Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
Warning:line 1561, column 14
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DwarfDebug.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
1//===- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains support for writing dwarf debug info into asm files.
10//
11//===----------------------------------------------------------------------===//
12
13#include "DwarfDebug.h"
14#include "ByteStreamer.h"
15#include "DIEHash.h"
16#include "DwarfCompileUnit.h"
17#include "DwarfExpression.h"
18#include "DwarfUnit.h"
19#include "llvm/ADT/APInt.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ADT/Triple.h"
22#include "llvm/ADT/Twine.h"
23#include "llvm/CodeGen/AsmPrinter.h"
24#include "llvm/CodeGen/DIE.h"
25#include "llvm/CodeGen/LexicalScopes.h"
26#include "llvm/CodeGen/MachineBasicBlock.h"
27#include "llvm/CodeGen/MachineFunction.h"
28#include "llvm/CodeGen/MachineModuleInfo.h"
29#include "llvm/CodeGen/MachineOperand.h"
30#include "llvm/CodeGen/TargetInstrInfo.h"
31#include "llvm/CodeGen/TargetLowering.h"
32#include "llvm/CodeGen/TargetRegisterInfo.h"
33#include "llvm/CodeGen/TargetSubtargetInfo.h"
34#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
35#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
36#include "llvm/IR/Constants.h"
37#include "llvm/IR/Function.h"
38#include "llvm/IR/GlobalVariable.h"
39#include "llvm/IR/Module.h"
40#include "llvm/MC/MCAsmInfo.h"
41#include "llvm/MC/MCContext.h"
42#include "llvm/MC/MCSection.h"
43#include "llvm/MC/MCStreamer.h"
44#include "llvm/MC/MCSymbol.h"
45#include "llvm/MC/MCTargetOptions.h"
46#include "llvm/MC/MachineLocation.h"
47#include "llvm/MC/SectionKind.h"
48#include "llvm/Pass.h"
49#include "llvm/Support/Casting.h"
50#include "llvm/Support/CommandLine.h"
51#include "llvm/Support/Debug.h"
52#include "llvm/Support/ErrorHandling.h"
53#include "llvm/Support/MD5.h"
54#include "llvm/Support/MathExtras.h"
55#include "llvm/Support/Timer.h"
56#include "llvm/Support/raw_ostream.h"
57#include "llvm/Target/TargetLoweringObjectFile.h"
58#include "llvm/Target/TargetMachine.h"
59#include <algorithm>
60#include <cstddef>
61#include <iterator>
62#include <string>
63
64using namespace llvm;
65
66#define DEBUG_TYPE"dwarfdebug" "dwarfdebug"
67
68STATISTIC(NumCSParams, "Number of dbg call site params created")static llvm::Statistic NumCSParams = {"dwarfdebug", "NumCSParams"
, "Number of dbg call site params created"};
69
70static cl::opt<bool> UseDwarfRangesBaseAddressSpecifier(
71 "use-dwarf-ranges-base-address-specifier", cl::Hidden,
72 cl::desc("Use base address specifiers in debug_ranges"), cl::init(false));
73
74static cl::opt<bool> GenerateARangeSection("generate-arange-section",
75 cl::Hidden,
76 cl::desc("Generate dwarf aranges"),
77 cl::init(false));
78
79static cl::opt<bool>
80 GenerateDwarfTypeUnits("generate-type-units", cl::Hidden,
81 cl::desc("Generate DWARF4 type units."),
82 cl::init(false));
83
84static cl::opt<bool> SplitDwarfCrossCuReferences(
85 "split-dwarf-cross-cu-references", cl::Hidden,
86 cl::desc("Enable cross-cu references in DWO files"), cl::init(false));
87
88enum DefaultOnOff { Default, Enable, Disable };
89
90static cl::opt<DefaultOnOff> UnknownLocations(
91 "use-unknown-locations", cl::Hidden,
92 cl::desc("Make an absence of debug location information explicit."),
93 cl::values(clEnumVal(Default, "At top of block or after label")llvm::cl::OptionEnumValue { "Default", int(Default), "At top of block or after label"
},
94 clEnumVal(Enable, "In all cases")llvm::cl::OptionEnumValue { "Enable", int(Enable), "In all cases"
}, clEnumVal(Disable, "Never")llvm::cl::OptionEnumValue { "Disable", int(Disable), "Never" }),
95 cl::init(Default));
96
97static cl::opt<AccelTableKind> AccelTables(
98 "accel-tables", cl::Hidden, cl::desc("Output dwarf accelerator tables."),
99 cl::values(clEnumValN(AccelTableKind::Default, "Default",llvm::cl::OptionEnumValue { "Default", int(AccelTableKind::Default
), "Default for platform" }
100 "Default for platform")llvm::cl::OptionEnumValue { "Default", int(AccelTableKind::Default
), "Default for platform" },
101 clEnumValN(AccelTableKind::None, "Disable", "Disabled.")llvm::cl::OptionEnumValue { "Disable", int(AccelTableKind::None
), "Disabled." },
102 clEnumValN(AccelTableKind::Apple, "Apple", "Apple")llvm::cl::OptionEnumValue { "Apple", int(AccelTableKind::Apple
), "Apple" },
103 clEnumValN(AccelTableKind::Dwarf, "Dwarf", "DWARF")llvm::cl::OptionEnumValue { "Dwarf", int(AccelTableKind::Dwarf
), "DWARF" }),
104 cl::init(AccelTableKind::Default));
105
106static cl::opt<DefaultOnOff>
107DwarfInlinedStrings("dwarf-inlined-strings", cl::Hidden,
108 cl::desc("Use inlined strings rather than string section."),
109 cl::values(clEnumVal(Default, "Default for platform")llvm::cl::OptionEnumValue { "Default", int(Default), "Default for platform"
},
110 clEnumVal(Enable, "Enabled")llvm::cl::OptionEnumValue { "Enable", int(Enable), "Enabled" },
111 clEnumVal(Disable, "Disabled")llvm::cl::OptionEnumValue { "Disable", int(Disable), "Disabled"
}),
112 cl::init(Default));
113
114static cl::opt<bool>
115 NoDwarfRangesSection("no-dwarf-ranges-section", cl::Hidden,
116 cl::desc("Disable emission .debug_ranges section."),
117 cl::init(false));
118
119static cl::opt<DefaultOnOff> DwarfSectionsAsReferences(
120 "dwarf-sections-as-references", cl::Hidden,
121 cl::desc("Use sections+offset as references rather than labels."),
122 cl::values(clEnumVal(Default, "Default for platform")llvm::cl::OptionEnumValue { "Default", int(Default), "Default for platform"
},
123 clEnumVal(Enable, "Enabled")llvm::cl::OptionEnumValue { "Enable", int(Enable), "Enabled" }, clEnumVal(Disable, "Disabled")llvm::cl::OptionEnumValue { "Disable", int(Disable), "Disabled"
}),
124 cl::init(Default));
125
126static cl::opt<bool>
127 UseGNUDebugMacro("use-gnu-debug-macro", cl::Hidden,
128 cl::desc("Emit the GNU .debug_macro format with DWARF <5"),
129 cl::init(false));
130
131static cl::opt<DefaultOnOff> DwarfOpConvert(
132 "dwarf-op-convert", cl::Hidden,
133 cl::desc("Enable use of the DWARFv5 DW_OP_convert operator"),
134 cl::values(clEnumVal(Default, "Default for platform")llvm::cl::OptionEnumValue { "Default", int(Default), "Default for platform"
},
135 clEnumVal(Enable, "Enabled")llvm::cl::OptionEnumValue { "Enable", int(Enable), "Enabled" }, clEnumVal(Disable, "Disabled")llvm::cl::OptionEnumValue { "Disable", int(Disable), "Disabled"
}),
136 cl::init(Default));
137
138enum LinkageNameOption {
139 DefaultLinkageNames,
140 AllLinkageNames,
141 AbstractLinkageNames
142};
143
144static cl::opt<LinkageNameOption>
145 DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
146 cl::desc("Which DWARF linkage-name attributes to emit."),
147 cl::values(clEnumValN(DefaultLinkageNames, "Default",llvm::cl::OptionEnumValue { "Default", int(DefaultLinkageNames
), "Default for platform" }
148 "Default for platform")llvm::cl::OptionEnumValue { "Default", int(DefaultLinkageNames
), "Default for platform" },
149 clEnumValN(AllLinkageNames, "All", "All")llvm::cl::OptionEnumValue { "All", int(AllLinkageNames), "All"
},
150 clEnumValN(AbstractLinkageNames, "Abstract",llvm::cl::OptionEnumValue { "Abstract", int(AbstractLinkageNames
), "Abstract subprograms" }
151 "Abstract subprograms")llvm::cl::OptionEnumValue { "Abstract", int(AbstractLinkageNames
), "Abstract subprograms" }),
152 cl::init(DefaultLinkageNames));
153
154static cl::opt<DwarfDebug::MinimizeAddrInV5> MinimizeAddrInV5Option(
155 "minimize-addr-in-v5", cl::Hidden,
156 cl::desc("Always use DW_AT_ranges in DWARFv5 whenever it could allow more "
157 "address pool entry sharing to reduce relocations/object size"),
158 cl::values(clEnumValN(DwarfDebug::MinimizeAddrInV5::Default, "Default",llvm::cl::OptionEnumValue { "Default", int(DwarfDebug::MinimizeAddrInV5
::Default), "Default address minimization strategy" }
159 "Default address minimization strategy")llvm::cl::OptionEnumValue { "Default", int(DwarfDebug::MinimizeAddrInV5
::Default), "Default address minimization strategy" },
160 clEnumValN(DwarfDebug::MinimizeAddrInV5::Ranges, "Ranges",llvm::cl::OptionEnumValue { "Ranges", int(DwarfDebug::MinimizeAddrInV5
::Ranges), "Use rnglists for contiguous ranges if that allows "
"using a pre-existing base address" }
161 "Use rnglists for contiguous ranges if that allows "llvm::cl::OptionEnumValue { "Ranges", int(DwarfDebug::MinimizeAddrInV5
::Ranges), "Use rnglists for contiguous ranges if that allows "
"using a pre-existing base address" }
162 "using a pre-existing base address")llvm::cl::OptionEnumValue { "Ranges", int(DwarfDebug::MinimizeAddrInV5
::Ranges), "Use rnglists for contiguous ranges if that allows "
"using a pre-existing base address" },
163 clEnumValN(DwarfDebug::MinimizeAddrInV5::Expressions,llvm::cl::OptionEnumValue { "Expressions", int(DwarfDebug::MinimizeAddrInV5
::Expressions), "Use exprloc addrx+offset expressions for any "
"address with a prior base address" }
164 "Expressions",llvm::cl::OptionEnumValue { "Expressions", int(DwarfDebug::MinimizeAddrInV5
::Expressions), "Use exprloc addrx+offset expressions for any "
"address with a prior base address" }
165 "Use exprloc addrx+offset expressions for any "llvm::cl::OptionEnumValue { "Expressions", int(DwarfDebug::MinimizeAddrInV5
::Expressions), "Use exprloc addrx+offset expressions for any "
"address with a prior base address" }
166 "address with a prior base address")llvm::cl::OptionEnumValue { "Expressions", int(DwarfDebug::MinimizeAddrInV5
::Expressions), "Use exprloc addrx+offset expressions for any "
"address with a prior base address" },
167 clEnumValN(DwarfDebug::MinimizeAddrInV5::Form, "Form",llvm::cl::OptionEnumValue { "Form", int(DwarfDebug::MinimizeAddrInV5
::Form), "Use addrx+offset extension form for any address " "with a prior base address"
}
168 "Use addrx+offset extension form for any address "llvm::cl::OptionEnumValue { "Form", int(DwarfDebug::MinimizeAddrInV5
::Form), "Use addrx+offset extension form for any address " "with a prior base address"
}
169 "with a prior base address")llvm::cl::OptionEnumValue { "Form", int(DwarfDebug::MinimizeAddrInV5
::Form), "Use addrx+offset extension form for any address " "with a prior base address"
},
170 clEnumValN(DwarfDebug::MinimizeAddrInV5::Disabled, "Disabled",llvm::cl::OptionEnumValue { "Disabled", int(DwarfDebug::MinimizeAddrInV5
::Disabled), "Stuff" }
171 "Stuff")llvm::cl::OptionEnumValue { "Disabled", int(DwarfDebug::MinimizeAddrInV5
::Disabled), "Stuff" }),
172 cl::init(DwarfDebug::MinimizeAddrInV5::Default));
173
174static constexpr unsigned ULEB128PadSize = 4;
175
176void DebugLocDwarfExpression::emitOp(uint8_t Op, const char *Comment) {
177 getActiveStreamer().emitInt8(
178 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
179 : dwarf::OperationEncodingString(Op));
180}
181
182void DebugLocDwarfExpression::emitSigned(int64_t Value) {
183 getActiveStreamer().emitSLEB128(Value, Twine(Value));
184}
185
186void DebugLocDwarfExpression::emitUnsigned(uint64_t Value) {
187 getActiveStreamer().emitULEB128(Value, Twine(Value));
188}
189
190void DebugLocDwarfExpression::emitData1(uint8_t Value) {
191 getActiveStreamer().emitInt8(Value, Twine(Value));
192}
193
194void DebugLocDwarfExpression::emitBaseTypeRef(uint64_t Idx) {
195 assert(Idx < (1ULL << (ULEB128PadSize * 7)) && "Idx wont fit")((void)0);
196 getActiveStreamer().emitULEB128(Idx, Twine(Idx), ULEB128PadSize);
197}
198
199bool DebugLocDwarfExpression::isFrameRegister(const TargetRegisterInfo &TRI,
200 llvm::Register MachineReg) {
201 // This information is not available while emitting .debug_loc entries.
202 return false;
203}
204
205void DebugLocDwarfExpression::enableTemporaryBuffer() {
206 assert(!IsBuffering && "Already buffering?")((void)0);
207 if (!TmpBuf)
208 TmpBuf = std::make_unique<TempBuffer>(OutBS.GenerateComments);
209 IsBuffering = true;
210}
211
212void DebugLocDwarfExpression::disableTemporaryBuffer() { IsBuffering = false; }
213
214unsigned DebugLocDwarfExpression::getTemporaryBufferSize() {
215 return TmpBuf ? TmpBuf->Bytes.size() : 0;
216}
217
218void DebugLocDwarfExpression::commitTemporaryBuffer() {
219 if (!TmpBuf)
220 return;
221 for (auto Byte : enumerate(TmpBuf->Bytes)) {
222 const char *Comment = (Byte.index() < TmpBuf->Comments.size())
223 ? TmpBuf->Comments[Byte.index()].c_str()
224 : "";
225 OutBS.emitInt8(Byte.value(), Comment);
226 }
227 TmpBuf->Bytes.clear();
228 TmpBuf->Comments.clear();
229}
230
231const DIType *DbgVariable::getType() const {
232 return getVariable()->getType();
233}
234
235/// Get .debug_loc entry for the instruction range starting at MI.
236static DbgValueLoc getDebugLocValue(const MachineInstr *MI) {
237 const DIExpression *Expr = MI->getDebugExpression();
238 const bool IsVariadic = MI->isDebugValueList();
239 assert(MI->getNumOperands() >= 3)((void)0);
240 SmallVector<DbgValueLocEntry, 4> DbgValueLocEntries;
241 for (const MachineOperand &Op : MI->debug_operands()) {
242 if (Op.isReg()) {
243 MachineLocation MLoc(Op.getReg(),
244 MI->isNonListDebugValue() && MI->isDebugOffsetImm());
245 DbgValueLocEntries.push_back(DbgValueLocEntry(MLoc));
246 } else if (Op.isTargetIndex()) {
247 DbgValueLocEntries.push_back(
248 DbgValueLocEntry(TargetIndexLocation(Op.getIndex(), Op.getOffset())));
249 } else if (Op.isImm())
250 DbgValueLocEntries.push_back(DbgValueLocEntry(Op.getImm()));
251 else if (Op.isFPImm())
252 DbgValueLocEntries.push_back(DbgValueLocEntry(Op.getFPImm()));
253 else if (Op.isCImm())
254 DbgValueLocEntries.push_back(DbgValueLocEntry(Op.getCImm()));
255 else
256 llvm_unreachable("Unexpected debug operand in DBG_VALUE* instruction!")__builtin_unreachable();
257 }
258 return DbgValueLoc(Expr, DbgValueLocEntries, IsVariadic);
259}
260
261void DbgVariable::initializeDbgValue(const MachineInstr *DbgValue) {
262 assert(FrameIndexExprs.empty() && "Already initialized?")((void)0);
263 assert(!ValueLoc.get() && "Already initialized?")((void)0);
264
265 assert(getVariable() == DbgValue->getDebugVariable() && "Wrong variable")((void)0);
266 assert(getInlinedAt() == DbgValue->getDebugLoc()->getInlinedAt() &&((void)0)
267 "Wrong inlined-at")((void)0);
268
269 ValueLoc = std::make_unique<DbgValueLoc>(getDebugLocValue(DbgValue));
270 if (auto *E = DbgValue->getDebugExpression())
271 if (E->getNumElements())
272 FrameIndexExprs.push_back({0, E});
273}
274
275ArrayRef<DbgVariable::FrameIndexExpr> DbgVariable::getFrameIndexExprs() const {
276 if (FrameIndexExprs.size() == 1)
277 return FrameIndexExprs;
278
279 assert(llvm::all_of(FrameIndexExprs,((void)0)
280 [](const FrameIndexExpr &A) {((void)0)
281 return A.Expr->isFragment();((void)0)
282 }) &&((void)0)
283 "multiple FI expressions without DW_OP_LLVM_fragment")((void)0);
284 llvm::sort(FrameIndexExprs,
285 [](const FrameIndexExpr &A, const FrameIndexExpr &B) -> bool {
286 return A.Expr->getFragmentInfo()->OffsetInBits <
287 B.Expr->getFragmentInfo()->OffsetInBits;
288 });
289
290 return FrameIndexExprs;
291}
292
293void DbgVariable::addMMIEntry(const DbgVariable &V) {
294 assert(DebugLocListIndex == ~0U && !ValueLoc.get() && "not an MMI entry")((void)0);
295 assert(V.DebugLocListIndex == ~0U && !V.ValueLoc.get() && "not an MMI entry")((void)0);
296 assert(V.getVariable() == getVariable() && "conflicting variable")((void)0);
297 assert(V.getInlinedAt() == getInlinedAt() && "conflicting inlined-at location")((void)0);
298
299 assert(!FrameIndexExprs.empty() && "Expected an MMI entry")((void)0);
300 assert(!V.FrameIndexExprs.empty() && "Expected an MMI entry")((void)0);
301
302 // FIXME: This logic should not be necessary anymore, as we now have proper
303 // deduplication. However, without it, we currently run into the assertion
304 // below, which means that we are likely dealing with broken input, i.e. two
305 // non-fragment entries for the same variable at different frame indices.
306 if (FrameIndexExprs.size()) {
307 auto *Expr = FrameIndexExprs.back().Expr;
308 if (!Expr || !Expr->isFragment())
309 return;
310 }
311
312 for (const auto &FIE : V.FrameIndexExprs)
313 // Ignore duplicate entries.
314 if (llvm::none_of(FrameIndexExprs, [&](const FrameIndexExpr &Other) {
315 return FIE.FI == Other.FI && FIE.Expr == Other.Expr;
316 }))
317 FrameIndexExprs.push_back(FIE);
318
319 assert((FrameIndexExprs.size() == 1 ||((void)0)
320 llvm::all_of(FrameIndexExprs,((void)0)
321 [](FrameIndexExpr &FIE) {((void)0)
322 return FIE.Expr && FIE.Expr->isFragment();((void)0)
323 })) &&((void)0)
324 "conflicting locations for variable")((void)0);
325}
326
327static AccelTableKind computeAccelTableKind(unsigned DwarfVersion,
328 bool GenerateTypeUnits,
329 DebuggerKind Tuning,
330 const Triple &TT) {
331 // Honor an explicit request.
332 if (AccelTables != AccelTableKind::Default)
333 return AccelTables;
334
335 // Accelerator tables with type units are currently not supported.
336 if (GenerateTypeUnits)
337 return AccelTableKind::None;
338
339 // Accelerator tables get emitted if targetting DWARF v5 or LLDB. DWARF v5
340 // always implies debug_names. For lower standard versions we use apple
341 // accelerator tables on apple platforms and debug_names elsewhere.
342 if (DwarfVersion >= 5)
343 return AccelTableKind::Dwarf;
344 if (Tuning == DebuggerKind::LLDB)
345 return TT.isOSBinFormatMachO() ? AccelTableKind::Apple
346 : AccelTableKind::Dwarf;
347 return AccelTableKind::None;
348}
349
350DwarfDebug::DwarfDebug(AsmPrinter *A)
351 : DebugHandlerBase(A), DebugLocs(A->OutStreamer->isVerboseAsm()),
352 InfoHolder(A, "info_string", DIEValueAllocator),
353 SkeletonHolder(A, "skel_string", DIEValueAllocator),
354 IsDarwin(A->TM.getTargetTriple().isOSDarwin()) {
355 const Triple &TT = Asm->TM.getTargetTriple();
356
357 // Make sure we know our "debugger tuning". The target option takes
358 // precedence; fall back to triple-based defaults.
359 if (Asm->TM.Options.DebuggerTuning != DebuggerKind::Default)
360 DebuggerTuning = Asm->TM.Options.DebuggerTuning;
361 else if (IsDarwin)
362 DebuggerTuning = DebuggerKind::LLDB;
363 else if (TT.isPS4CPU())
364 DebuggerTuning = DebuggerKind::SCE;
365 else if (TT.isOSAIX())
366 DebuggerTuning = DebuggerKind::DBX;
367 else
368 DebuggerTuning = DebuggerKind::GDB;
369
370 if (DwarfInlinedStrings == Default)
371 UseInlineStrings = TT.isNVPTX() || tuneForDBX();
372 else
373 UseInlineStrings = DwarfInlinedStrings == Enable;
374
375 UseLocSection = !TT.isNVPTX();
376
377 HasAppleExtensionAttributes = tuneForLLDB();
378
379 // Handle split DWARF.
380 HasSplitDwarf = !Asm->TM.Options.MCOptions.SplitDwarfFile.empty();
381
382 // SCE defaults to linkage names only for abstract subprograms.
383 if (DwarfLinkageNames == DefaultLinkageNames)
384 UseAllLinkageNames = !tuneForSCE();
385 else
386 UseAllLinkageNames = DwarfLinkageNames == AllLinkageNames;
387
388 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
389 unsigned DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
390 : MMI->getModule()->getDwarfVersion();
391 // Use dwarf 4 by default if nothing is requested. For NVPTX, use dwarf 2.
392 DwarfVersion =
393 TT.isNVPTX() ? 2 : (DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION);
394
395 bool Dwarf64 = DwarfVersion >= 3 && // DWARF64 was introduced in DWARFv3.
396 TT.isArch64Bit(); // DWARF64 requires 64-bit relocations.
397
398 // Support DWARF64
399 // 1: For ELF when requested.
400 // 2: For XCOFF64: the AIX assembler will fill in debug section lengths
401 // according to the DWARF64 format for 64-bit assembly, so we must use
402 // DWARF64 in the compiler too for 64-bit mode.
403 Dwarf64 &=
404 ((Asm->TM.Options.MCOptions.Dwarf64 || MMI->getModule()->isDwarf64()) &&
405 TT.isOSBinFormatELF()) ||
406 TT.isOSBinFormatXCOFF();
407
408 if (!Dwarf64 && TT.isArch64Bit() && TT.isOSBinFormatXCOFF())
409 report_fatal_error("XCOFF requires DWARF64 for 64-bit mode!");
410
411 UseRangesSection = !NoDwarfRangesSection && !TT.isNVPTX();
412
413 // Use sections as references. Force for NVPTX.
414 if (DwarfSectionsAsReferences == Default)
415 UseSectionsAsReferences = TT.isNVPTX();
416 else
417 UseSectionsAsReferences = DwarfSectionsAsReferences == Enable;
418
419 // Don't generate type units for unsupported object file formats.
420 GenerateTypeUnits = (A->TM.getTargetTriple().isOSBinFormatELF() ||
421 A->TM.getTargetTriple().isOSBinFormatWasm()) &&
422 GenerateDwarfTypeUnits;
423
424 TheAccelTableKind = computeAccelTableKind(
425 DwarfVersion, GenerateTypeUnits, DebuggerTuning, A->TM.getTargetTriple());
426
427 // Work around a GDB bug. GDB doesn't support the standard opcode;
428 // SCE doesn't support GNU's; LLDB prefers the standard opcode, which
429 // is defined as of DWARF 3.
430 // See GDB bug 11616 - DW_OP_form_tls_address is unimplemented
431 // https://sourceware.org/bugzilla/show_bug.cgi?id=11616
432 UseGNUTLSOpcode = tuneForGDB() || DwarfVersion < 3;
433
434 // GDB does not fully support the DWARF 4 representation for bitfields.
435 UseDWARF2Bitfields = (DwarfVersion < 4) || tuneForGDB();
436
437 // The DWARF v5 string offsets table has - possibly shared - contributions
438 // from each compile and type unit each preceded by a header. The string
439 // offsets table used by the pre-DWARF v5 split-DWARF implementation uses
440 // a monolithic string offsets table without any header.
441 UseSegmentedStringOffsetsTable = DwarfVersion >= 5;
442
443 // Emit call-site-param debug info for GDB and LLDB, if the target supports
444 // the debug entry values feature. It can also be enabled explicitly.
445 EmitDebugEntryValues = Asm->TM.Options.ShouldEmitDebugEntryValues();
446
447 // It is unclear if the GCC .debug_macro extension is well-specified
448 // for split DWARF. For now, do not allow LLVM to emit it.
449 UseDebugMacroSection =
450 DwarfVersion >= 5 || (UseGNUDebugMacro && !useSplitDwarf());
451 if (DwarfOpConvert == Default)
452 EnableOpConvert = !((tuneForGDB() && useSplitDwarf()) || (tuneForLLDB() && !TT.isOSBinFormatMachO()));
453 else
454 EnableOpConvert = (DwarfOpConvert == Enable);
455
456 // Split DWARF would benefit object size significantly by trading reductions
457 // in address pool usage for slightly increased range list encodings.
458 if (DwarfVersion >= 5) {
459 MinimizeAddr = MinimizeAddrInV5Option;
460 // FIXME: In the future, enable this by default for Split DWARF where the
461 // tradeoff is more pronounced due to being able to offload the range
462 // lists to the dwo file and shrink object files/reduce relocations there.
463 if (MinimizeAddr == MinimizeAddrInV5::Default)
464 MinimizeAddr = MinimizeAddrInV5::Disabled;
465 }
466
467 Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
468 Asm->OutStreamer->getContext().setDwarfFormat(Dwarf64 ? dwarf::DWARF64
469 : dwarf::DWARF32);
470}
471
472// Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
473DwarfDebug::~DwarfDebug() = default;
474
475static bool isObjCClass(StringRef Name) {
476 return Name.startswith("+") || Name.startswith("-");
477}
478
479static bool hasObjCCategory(StringRef Name) {
480 if (!isObjCClass(Name))
481 return false;
482
483 return Name.find(") ") != StringRef::npos;
484}
485
486static void getObjCClassCategory(StringRef In, StringRef &Class,
487 StringRef &Category) {
488 if (!hasObjCCategory(In)) {
489 Class = In.slice(In.find('[') + 1, In.find(' '));
490 Category = "";
491 return;
492 }
493
494 Class = In.slice(In.find('[') + 1, In.find('('));
495 Category = In.slice(In.find('[') + 1, In.find(' '));
496}
497
498static StringRef getObjCMethodName(StringRef In) {
499 return In.slice(In.find(' ') + 1, In.find(']'));
500}
501
502// Add the various names to the Dwarf accelerator table names.
503void DwarfDebug::addSubprogramNames(const DICompileUnit &CU,
504 const DISubprogram *SP, DIE &Die) {
505 if (getAccelTableKind() != AccelTableKind::Apple &&
506 CU.getNameTableKind() == DICompileUnit::DebugNameTableKind::None)
507 return;
508
509 if (!SP->isDefinition())
510 return;
511
512 if (SP->getName() != "")
513 addAccelName(CU, SP->getName(), Die);
514
515 // If the linkage name is different than the name, go ahead and output that as
516 // well into the name table. Only do that if we are going to actually emit
517 // that name.
518 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName() &&
519 (useAllLinkageNames() || InfoHolder.getAbstractSPDies().lookup(SP)))
520 addAccelName(CU, SP->getLinkageName(), Die);
521
522 // If this is an Objective-C selector name add it to the ObjC accelerator
523 // too.
524 if (isObjCClass(SP->getName())) {
525 StringRef Class, Category;
526 getObjCClassCategory(SP->getName(), Class, Category);
527 addAccelObjC(CU, Class, Die);
528 if (Category != "")
529 addAccelObjC(CU, Category, Die);
530 // Also add the base method name to the name table.
531 addAccelName(CU, getObjCMethodName(SP->getName()), Die);
532 }
533}
534
535/// Check whether we should create a DIE for the given Scope, return true
536/// if we don't create a DIE (the corresponding DIE is null).
537bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
538 if (Scope->isAbstractScope())
539 return false;
540
541 // We don't create a DIE if there is no Range.
542 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
543 if (Ranges.empty())
544 return true;
545
546 if (Ranges.size() > 1)
547 return false;
548
549 // We don't create a DIE if we have a single Range and the end label
550 // is null.
551 return !getLabelAfterInsn(Ranges.front().second);
552}
553
554template <typename Func> static void forBothCUs(DwarfCompileUnit &CU, Func F) {
555 F(CU);
556 if (auto *SkelCU = CU.getSkeleton())
557 if (CU.getCUNode()->getSplitDebugInlining())
558 F(*SkelCU);
559}
560
561bool DwarfDebug::shareAcrossDWOCUs() const {
562 return SplitDwarfCrossCuReferences;
563}
564
565void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &SrcCU,
566 LexicalScope *Scope) {
567 assert(Scope && Scope->getScopeNode())((void)0);
568 assert(Scope->isAbstractScope())((void)0);
569 assert(!Scope->getInlinedAt())((void)0);
570
571 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
572
573 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
574 // was inlined from another compile unit.
575 if (useSplitDwarf() && !shareAcrossDWOCUs() && !SP->getUnit()->getSplitDebugInlining())
576 // Avoid building the original CU if it won't be used
577 SrcCU.constructAbstractSubprogramScopeDIE(Scope);
578 else {
579 auto &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
580 if (auto *SkelCU = CU.getSkeleton()) {
581 (shareAcrossDWOCUs() ? CU : SrcCU)
582 .constructAbstractSubprogramScopeDIE(Scope);
583 if (CU.getCUNode()->getSplitDebugInlining())
584 SkelCU->constructAbstractSubprogramScopeDIE(Scope);
585 } else
586 CU.constructAbstractSubprogramScopeDIE(Scope);
587 }
588}
589
590/// Represents a parameter whose call site value can be described by applying a
591/// debug expression to a register in the forwarded register worklist.
592struct FwdRegParamInfo {
593 /// The described parameter register.
594 unsigned ParamReg;
595
596 /// Debug expression that has been built up when walking through the
597 /// instruction chain that produces the parameter's value.
598 const DIExpression *Expr;
599};
600
601/// Register worklist for finding call site values.
602using FwdRegWorklist = MapVector<unsigned, SmallVector<FwdRegParamInfo, 2>>;
603
604/// Append the expression \p Addition to \p Original and return the result.
605static const DIExpression *combineDIExpressions(const DIExpression *Original,
606 const DIExpression *Addition) {
607 std::vector<uint64_t> Elts = Addition->getElements().vec();
608 // Avoid multiple DW_OP_stack_values.
609 if (Original->isImplicit() && Addition->isImplicit())
610 erase_value(Elts, dwarf::DW_OP_stack_value);
611 const DIExpression *CombinedExpr =
612 (Elts.size() > 0) ? DIExpression::append(Original, Elts) : Original;
613 return CombinedExpr;
614}
615
616/// Emit call site parameter entries that are described by the given value and
617/// debug expression.
618template <typename ValT>
619static void finishCallSiteParams(ValT Val, const DIExpression *Expr,
620 ArrayRef<FwdRegParamInfo> DescribedParams,
621 ParamSet &Params) {
622 for (auto Param : DescribedParams) {
623 bool ShouldCombineExpressions = Expr && Param.Expr->getNumElements() > 0;
624
625 // TODO: Entry value operations can currently not be combined with any
626 // other expressions, so we can't emit call site entries in those cases.
627 if (ShouldCombineExpressions && Expr->isEntryValue())
628 continue;
629
630 // If a parameter's call site value is produced by a chain of
631 // instructions we may have already created an expression for the
632 // parameter when walking through the instructions. Append that to the
633 // base expression.
634 const DIExpression *CombinedExpr =
635 ShouldCombineExpressions ? combineDIExpressions(Expr, Param.Expr)
636 : Expr;
637 assert((!CombinedExpr || CombinedExpr->isValid()) &&((void)0)
638 "Combined debug expression is invalid")((void)0);
639
640 DbgValueLoc DbgLocVal(CombinedExpr, DbgValueLocEntry(Val));
641 DbgCallSiteParam CSParm(Param.ParamReg, DbgLocVal);
642 Params.push_back(CSParm);
643 ++NumCSParams;
644 }
645}
646
647/// Add \p Reg to the worklist, if it's not already present, and mark that the
648/// given parameter registers' values can (potentially) be described using
649/// that register and an debug expression.
650static void addToFwdRegWorklist(FwdRegWorklist &Worklist, unsigned Reg,
651 const DIExpression *Expr,
652 ArrayRef<FwdRegParamInfo> ParamsToAdd) {
653 auto I = Worklist.insert({Reg, {}});
654 auto &ParamsForFwdReg = I.first->second;
655 for (auto Param : ParamsToAdd) {
656 assert(none_of(ParamsForFwdReg,((void)0)
657 [Param](const FwdRegParamInfo &D) {((void)0)
658 return D.ParamReg == Param.ParamReg;((void)0)
659 }) &&((void)0)
660 "Same parameter described twice by forwarding reg")((void)0);
661
662 // If a parameter's call site value is produced by a chain of
663 // instructions we may have already created an expression for the
664 // parameter when walking through the instructions. Append that to the
665 // new expression.
666 const DIExpression *CombinedExpr = combineDIExpressions(Expr, Param.Expr);
667 ParamsForFwdReg.push_back({Param.ParamReg, CombinedExpr});
668 }
669}
670
671/// Interpret values loaded into registers by \p CurMI.
672static void interpretValues(const MachineInstr *CurMI,
673 FwdRegWorklist &ForwardedRegWorklist,
674 ParamSet &Params) {
675
676 const MachineFunction *MF = CurMI->getMF();
677 const DIExpression *EmptyExpr =
678 DIExpression::get(MF->getFunction().getContext(), {});
679 const auto &TRI = *MF->getSubtarget().getRegisterInfo();
680 const auto &TII = *MF->getSubtarget().getInstrInfo();
681 const auto &TLI = *MF->getSubtarget().getTargetLowering();
682
683 // If an instruction defines more than one item in the worklist, we may run
684 // into situations where a worklist register's value is (potentially)
685 // described by the previous value of another register that is also defined
686 // by that instruction.
687 //
688 // This can for example occur in cases like this:
689 //
690 // $r1 = mov 123
691 // $r0, $r1 = mvrr $r1, 456
692 // call @foo, $r0, $r1
693 //
694 // When describing $r1's value for the mvrr instruction, we need to make sure
695 // that we don't finalize an entry value for $r0, as that is dependent on the
696 // previous value of $r1 (123 rather than 456).
697 //
698 // In order to not have to distinguish between those cases when finalizing
699 // entry values, we simply postpone adding new parameter registers to the
700 // worklist, by first keeping them in this temporary container until the
701 // instruction has been handled.
702 FwdRegWorklist TmpWorklistItems;
703
704 // If the MI is an instruction defining one or more parameters' forwarding
705 // registers, add those defines.
706 auto getForwardingRegsDefinedByMI = [&](const MachineInstr &MI,
707 SmallSetVector<unsigned, 4> &Defs) {
708 if (MI.isDebugInstr())
709 return;
710
711 for (const MachineOperand &MO : MI.operands()) {
712 if (MO.isReg() && MO.isDef() &&
713 Register::isPhysicalRegister(MO.getReg())) {
714 for (auto &FwdReg : ForwardedRegWorklist)
715 if (TRI.regsOverlap(FwdReg.first, MO.getReg()))
716 Defs.insert(FwdReg.first);
717 }
718 }
719 };
720
721 // Set of worklist registers that are defined by this instruction.
722 SmallSetVector<unsigned, 4> FwdRegDefs;
723
724 getForwardingRegsDefinedByMI(*CurMI, FwdRegDefs);
725 if (FwdRegDefs.empty())
726 return;
727
728 for (auto ParamFwdReg : FwdRegDefs) {
729 if (auto ParamValue = TII.describeLoadedValue(*CurMI, ParamFwdReg)) {
730 if (ParamValue->first.isImm()) {
731 int64_t Val = ParamValue->first.getImm();
732 finishCallSiteParams(Val, ParamValue->second,
733 ForwardedRegWorklist[ParamFwdReg], Params);
734 } else if (ParamValue->first.isReg()) {
735 Register RegLoc = ParamValue->first.getReg();
736 Register SP = TLI.getStackPointerRegisterToSaveRestore();
737 Register FP = TRI.getFrameRegister(*MF);
738 bool IsSPorFP = (RegLoc == SP) || (RegLoc == FP);
739 if (TRI.isCalleeSavedPhysReg(RegLoc, *MF) || IsSPorFP) {
740 MachineLocation MLoc(RegLoc, /*Indirect=*/IsSPorFP);
741 finishCallSiteParams(MLoc, ParamValue->second,
742 ForwardedRegWorklist[ParamFwdReg], Params);
743 } else {
744 // ParamFwdReg was described by the non-callee saved register
745 // RegLoc. Mark that the call site values for the parameters are
746 // dependent on that register instead of ParamFwdReg. Since RegLoc
747 // may be a register that will be handled in this iteration, we
748 // postpone adding the items to the worklist, and instead keep them
749 // in a temporary container.
750 addToFwdRegWorklist(TmpWorklistItems, RegLoc, ParamValue->second,
751 ForwardedRegWorklist[ParamFwdReg]);
752 }
753 }
754 }
755 }
756
757 // Remove all registers that this instruction defines from the worklist.
758 for (auto ParamFwdReg : FwdRegDefs)
759 ForwardedRegWorklist.erase(ParamFwdReg);
760
761 // Now that we are done handling this instruction, add items from the
762 // temporary worklist to the real one.
763 for (auto &New : TmpWorklistItems)
764 addToFwdRegWorklist(ForwardedRegWorklist, New.first, EmptyExpr, New.second);
765 TmpWorklistItems.clear();
766}
767
768static bool interpretNextInstr(const MachineInstr *CurMI,
769 FwdRegWorklist &ForwardedRegWorklist,
770 ParamSet &Params) {
771 // Skip bundle headers.
772 if (CurMI->isBundle())
773 return true;
774
775 // If the next instruction is a call we can not interpret parameter's
776 // forwarding registers or we finished the interpretation of all
777 // parameters.
778 if (CurMI->isCall())
779 return false;
780
781 if (ForwardedRegWorklist.empty())
782 return false;
783
784 // Avoid NOP description.
785 if (CurMI->getNumOperands() == 0)
786 return true;
787
788 interpretValues(CurMI, ForwardedRegWorklist, Params);
789
790 return true;
791}
792
793/// Try to interpret values loaded into registers that forward parameters
794/// for \p CallMI. Store parameters with interpreted value into \p Params.
795static void collectCallSiteParameters(const MachineInstr *CallMI,
796 ParamSet &Params) {
797 const MachineFunction *MF = CallMI->getMF();
798 const auto &CalleesMap = MF->getCallSitesInfo();
799 auto CallFwdRegsInfo = CalleesMap.find(CallMI);
800
801 // There is no information for the call instruction.
802 if (CallFwdRegsInfo == CalleesMap.end())
803 return;
804
805 const MachineBasicBlock *MBB = CallMI->getParent();
806
807 // Skip the call instruction.
808 auto I = std::next(CallMI->getReverseIterator());
809
810 FwdRegWorklist ForwardedRegWorklist;
811
812 const DIExpression *EmptyExpr =
813 DIExpression::get(MF->getFunction().getContext(), {});
814
815 // Add all the forwarding registers into the ForwardedRegWorklist.
816 for (const auto &ArgReg : CallFwdRegsInfo->second) {
817 bool InsertedReg =
818 ForwardedRegWorklist.insert({ArgReg.Reg, {{ArgReg.Reg, EmptyExpr}}})
819 .second;
820 assert(InsertedReg && "Single register used to forward two arguments?")((void)0);
821 (void)InsertedReg;
822 }
823
824 // Do not emit CSInfo for undef forwarding registers.
825 for (auto &MO : CallMI->uses())
826 if (MO.isReg() && MO.isUndef())
827 ForwardedRegWorklist.erase(MO.getReg());
828
829 // We erase, from the ForwardedRegWorklist, those forwarding registers for
830 // which we successfully describe a loaded value (by using
831 // the describeLoadedValue()). For those remaining arguments in the working
832 // list, for which we do not describe a loaded value by
833 // the describeLoadedValue(), we try to generate an entry value expression
834 // for their call site value description, if the call is within the entry MBB.
835 // TODO: Handle situations when call site parameter value can be described
836 // as the entry value within basic blocks other than the first one.
837 bool ShouldTryEmitEntryVals = MBB->getIterator() == MF->begin();
838
839 // Search for a loading value in forwarding registers inside call delay slot.
840 if (CallMI->hasDelaySlot()) {
841 auto Suc = std::next(CallMI->getIterator());
842 // Only one-instruction delay slot is supported.
843 auto BundleEnd = llvm::getBundleEnd(CallMI->getIterator());
844 (void)BundleEnd;
845 assert(std::next(Suc) == BundleEnd &&((void)0)
846 "More than one instruction in call delay slot")((void)0);
847 // Try to interpret value loaded by instruction.
848 if (!interpretNextInstr(&*Suc, ForwardedRegWorklist, Params))
849 return;
850 }
851
852 // Search for a loading value in forwarding registers.
853 for (; I != MBB->rend(); ++I) {
854 // Try to interpret values loaded by instruction.
855 if (!interpretNextInstr(&*I, ForwardedRegWorklist, Params))
856 return;
857 }
858
859 // Emit the call site parameter's value as an entry value.
860 if (ShouldTryEmitEntryVals) {
861 // Create an expression where the register's entry value is used.
862 DIExpression *EntryExpr = DIExpression::get(
863 MF->getFunction().getContext(), {dwarf::DW_OP_LLVM_entry_value, 1});
864 for (auto &RegEntry : ForwardedRegWorklist) {
865 MachineLocation MLoc(RegEntry.first);
866 finishCallSiteParams(MLoc, EntryExpr, RegEntry.second, Params);
867 }
868 }
869}
870
871void DwarfDebug::constructCallSiteEntryDIEs(const DISubprogram &SP,
872 DwarfCompileUnit &CU, DIE &ScopeDIE,
873 const MachineFunction &MF) {
874 // Add a call site-related attribute (DWARF5, Sec. 3.3.1.3). Do this only if
875 // the subprogram is required to have one.
876 if (!SP.areAllCallsDescribed() || !SP.isDefinition())
877 return;
878
879 // Use DW_AT_call_all_calls to express that call site entries are present
880 // for both tail and non-tail calls. Don't use DW_AT_call_all_source_calls
881 // because one of its requirements is not met: call site entries for
882 // optimized-out calls are elided.
883 CU.addFlag(ScopeDIE, CU.getDwarf5OrGNUAttr(dwarf::DW_AT_call_all_calls));
884
885 const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
886 assert(TII && "TargetInstrInfo not found: cannot label tail calls")((void)0);
887
888 // Delay slot support check.
889 auto delaySlotSupported = [&](const MachineInstr &MI) {
890 if (!MI.isBundledWithSucc())
891 return false;
892 auto Suc = std::next(MI.getIterator());
893 auto CallInstrBundle = getBundleStart(MI.getIterator());
894 (void)CallInstrBundle;
895 auto DelaySlotBundle = getBundleStart(Suc);
896 (void)DelaySlotBundle;
897 // Ensure that label after call is following delay slot instruction.
898 // Ex. CALL_INSTRUCTION {
899 // DELAY_SLOT_INSTRUCTION }
900 // LABEL_AFTER_CALL
901 assert(getLabelAfterInsn(&*CallInstrBundle) ==((void)0)
902 getLabelAfterInsn(&*DelaySlotBundle) &&((void)0)
903 "Call and its successor instruction don't have same label after.")((void)0);
904 return true;
905 };
906
907 // Emit call site entries for each call or tail call in the function.
908 for (const MachineBasicBlock &MBB : MF) {
909 for (const MachineInstr &MI : MBB.instrs()) {
910 // Bundles with call in them will pass the isCall() test below but do not
911 // have callee operand information so skip them here. Iterator will
912 // eventually reach the call MI.
913 if (MI.isBundle())
914 continue;
915
916 // Skip instructions which aren't calls. Both calls and tail-calling jump
917 // instructions (e.g TAILJMPd64) are classified correctly here.
918 if (!MI.isCandidateForCallSiteEntry())
919 continue;
920
921 // Skip instructions marked as frame setup, as they are not interesting to
922 // the user.
923 if (MI.getFlag(MachineInstr::FrameSetup))
924 continue;
925
926 // Check if delay slot support is enabled.
927 if (MI.hasDelaySlot() && !delaySlotSupported(*&MI))
928 return;
929
930 // If this is a direct call, find the callee's subprogram.
931 // In the case of an indirect call find the register that holds
932 // the callee.
933 const MachineOperand &CalleeOp = TII->getCalleeOperand(MI);
934 if (!CalleeOp.isGlobal() &&
935 (!CalleeOp.isReg() ||
936 !Register::isPhysicalRegister(CalleeOp.getReg())))
937 continue;
938
939 unsigned CallReg = 0;
940 const DISubprogram *CalleeSP = nullptr;
941 const Function *CalleeDecl = nullptr;
942 if (CalleeOp.isReg()) {
943 CallReg = CalleeOp.getReg();
944 if (!CallReg)
945 continue;
946 } else {
947 CalleeDecl = dyn_cast<Function>(CalleeOp.getGlobal());
948 if (!CalleeDecl || !CalleeDecl->getSubprogram())
949 continue;
950 CalleeSP = CalleeDecl->getSubprogram();
951 }
952
953 // TODO: Omit call site entries for runtime calls (objc_msgSend, etc).
954
955 bool IsTail = TII->isTailCall(MI);
956
957 // If MI is in a bundle, the label was created after the bundle since
958 // EmitFunctionBody iterates over top-level MIs. Get that top-level MI
959 // to search for that label below.
960 const MachineInstr *TopLevelCallMI =
961 MI.isInsideBundle() ? &*getBundleStart(MI.getIterator()) : &MI;
962
963 // For non-tail calls, the return PC is needed to disambiguate paths in
964 // the call graph which could lead to some target function. For tail
965 // calls, no return PC information is needed, unless tuning for GDB in
966 // DWARF4 mode in which case we fake a return PC for compatibility.
967 const MCSymbol *PCAddr =
968 (!IsTail || CU.useGNUAnalogForDwarf5Feature())
969 ? const_cast<MCSymbol *>(getLabelAfterInsn(TopLevelCallMI))
970 : nullptr;
971
972 // For tail calls, it's necessary to record the address of the branch
973 // instruction so that the debugger can show where the tail call occurred.
974 const MCSymbol *CallAddr =
975 IsTail ? getLabelBeforeInsn(TopLevelCallMI) : nullptr;
976
977 assert((IsTail || PCAddr) && "Non-tail call without return PC")((void)0);
978
979 LLVM_DEBUG(dbgs() << "CallSiteEntry: " << MF.getName() << " -> "do { } while (false)
980 << (CalleeDecl ? CalleeDecl->getName()do { } while (false)
981 : StringRef(MF.getSubtarget()do { } while (false)
982 .getRegisterInfo()do { } while (false)
983 ->getName(CallReg)))do { } while (false)
984 << (IsTail ? " [IsTail]" : "") << "\n")do { } while (false);
985
986 DIE &CallSiteDIE = CU.constructCallSiteEntryDIE(
987 ScopeDIE, CalleeSP, IsTail, PCAddr, CallAddr, CallReg);
988
989 // Optionally emit call-site-param debug info.
990 if (emitDebugEntryValues()) {
991 ParamSet Params;
992 // Try to interpret values of call site parameters.
993 collectCallSiteParameters(&MI, Params);
994 CU.constructCallSiteParmEntryDIEs(CallSiteDIE, Params);
995 }
996 }
997 }
998}
999
1000void DwarfDebug::addGnuPubAttributes(DwarfCompileUnit &U, DIE &D) const {
1001 if (!U.hasDwarfPubSections())
1002 return;
1003
1004 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
1005}
1006
1007void DwarfDebug::finishUnitAttributes(const DICompileUnit *DIUnit,
1008 DwarfCompileUnit &NewCU) {
1009 DIE &Die = NewCU.getUnitDie();
1010 StringRef FN = DIUnit->getFilename();
1011
1012 StringRef Producer = DIUnit->getProducer();
1013 StringRef Flags = DIUnit->getFlags();
1014 if (!Flags.empty() && !useAppleExtensionAttributes()) {
1015 std::string ProducerWithFlags = Producer.str() + " " + Flags.str();
1016 NewCU.addString(Die, dwarf::DW_AT_producer, ProducerWithFlags);
1017 } else
1018 NewCU.addString(Die, dwarf::DW_AT_producer, Producer);
1019
1020 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1021 DIUnit->getSourceLanguage());
1022 NewCU.addString(Die, dwarf::DW_AT_name, FN);
1023 StringRef SysRoot = DIUnit->getSysRoot();
1024 if (!SysRoot.empty())
1025 NewCU.addString(Die, dwarf::DW_AT_LLVM_sysroot, SysRoot);
1026 StringRef SDK = DIUnit->getSDK();
1027 if (!SDK.empty())
1028 NewCU.addString(Die, dwarf::DW_AT_APPLE_sdk, SDK);
1029
1030 // Add DW_str_offsets_base to the unit DIE, except for split units.
1031 if (useSegmentedStringOffsetsTable() && !useSplitDwarf())
1032 NewCU.addStringOffsetsStart();
1033
1034 if (!useSplitDwarf()) {
1035 NewCU.initStmtList();
1036
1037 // If we're using split dwarf the compilation dir is going to be in the
1038 // skeleton CU and so we don't need to duplicate it here.
1039 if (!CompilationDir.empty())
1040 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1041 addGnuPubAttributes(NewCU, Die);
1042 }
1043
1044 if (useAppleExtensionAttributes()) {
1045 if (DIUnit->isOptimized())
1046 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
1047
1048 StringRef Flags = DIUnit->getFlags();
1049 if (!Flags.empty())
1050 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
1051
1052 if (unsigned RVer = DIUnit->getRuntimeVersion())
1053 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
1054 dwarf::DW_FORM_data1, RVer);
1055 }
1056
1057 if (DIUnit->getDWOId()) {
1058 // This CU is either a clang module DWO or a skeleton CU.
1059 NewCU.addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8,
1060 DIUnit->getDWOId());
1061 if (!DIUnit->getSplitDebugFilename().empty()) {
1062 // This is a prefabricated skeleton CU.
1063 dwarf::Attribute attrDWOName = getDwarfVersion() >= 5
1064 ? dwarf::DW_AT_dwo_name
1065 : dwarf::DW_AT_GNU_dwo_name;
1066 NewCU.addString(Die, attrDWOName, DIUnit->getSplitDebugFilename());
1067 }
1068 }
1069}
1070// Create new DwarfCompileUnit for the given metadata node with tag
1071// DW_TAG_compile_unit.
1072DwarfCompileUnit &
1073DwarfDebug::getOrCreateDwarfCompileUnit(const DICompileUnit *DIUnit) {
1074 if (auto *CU = CUMap.lookup(DIUnit))
1075 return *CU;
1076
1077 CompilationDir = DIUnit->getDirectory();
1078
1079 auto OwnedUnit = std::make_unique<DwarfCompileUnit>(
1080 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
1081 DwarfCompileUnit &NewCU = *OwnedUnit;
1082 InfoHolder.addUnit(std::move(OwnedUnit));
1083
1084 for (auto *IE : DIUnit->getImportedEntities())
1085 NewCU.addImportedEntity(IE);
1086
1087 // LTO with assembly output shares a single line table amongst multiple CUs.
1088 // To avoid the compilation directory being ambiguous, let the line table
1089 // explicitly describe the directory of all files, never relying on the
1090 // compilation directory.
1091 if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
1092 Asm->OutStreamer->emitDwarfFile0Directive(
1093 CompilationDir, DIUnit->getFilename(), getMD5AsBytes(DIUnit->getFile()),
1094 DIUnit->getSource(), NewCU.getUniqueID());
1095
1096 if (useSplitDwarf()) {
1097 NewCU.setSkeleton(constructSkeletonCU(NewCU));
1098 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
1099 } else {
1100 finishUnitAttributes(DIUnit, NewCU);
1101 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());
1102 }
1103
1104 // Create DIEs for function declarations used for call site debug info.
1105 for (auto Scope : DIUnit->getRetainedTypes())
1106 if (auto *SP = dyn_cast_or_null<DISubprogram>(Scope))
1107 NewCU.getOrCreateSubprogramDIE(SP);
1108
1109 CUMap.insert({DIUnit, &NewCU});
1110 CUDieMap.insert({&NewCU.getUnitDie(), &NewCU});
1111 return NewCU;
1112}
1113
1114void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
1115 const DIImportedEntity *N) {
1116 if (isa<DILocalScope>(N->getScope()))
1117 return;
1118 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
1119 D->addChild(TheCU.constructImportedEntityDIE(N));
1120}
1121
1122/// Sort and unique GVEs by comparing their fragment offset.
1123static SmallVectorImpl<DwarfCompileUnit::GlobalExpr> &
1124sortGlobalExprs(SmallVectorImpl<DwarfCompileUnit::GlobalExpr> &GVEs) {
1125 llvm::sort(
1126 GVEs, [](DwarfCompileUnit::GlobalExpr A, DwarfCompileUnit::GlobalExpr B) {
1127 // Sort order: first null exprs, then exprs without fragment
1128 // info, then sort by fragment offset in bits.
1129 // FIXME: Come up with a more comprehensive comparator so
1130 // the sorting isn't non-deterministic, and so the following
1131 // std::unique call works correctly.
1132 if (!A.Expr || !B.Expr)
1133 return !!B.Expr;
1134 auto FragmentA = A.Expr->getFragmentInfo();
1135 auto FragmentB = B.Expr->getFragmentInfo();
1136 if (!FragmentA || !FragmentB)
1137 return !!FragmentB;
1138 return FragmentA->OffsetInBits < FragmentB->OffsetInBits;
1139 });
1140 GVEs.erase(std::unique(GVEs.begin(), GVEs.end(),
1141 [](DwarfCompileUnit::GlobalExpr A,
1142 DwarfCompileUnit::GlobalExpr B) {
1143 return A.Expr == B.Expr;
1144 }),
1145 GVEs.end());
1146 return GVEs;
1147}
1148
1149// Emit all Dwarf sections that should come prior to the content. Create
1150// global DIEs and emit initial debug info sections. This is invoked by
1151// the target AsmPrinter.
1152void DwarfDebug::beginModule(Module *M) {
1153 DebugHandlerBase::beginModule(M);
1154
1155 if (!Asm || !MMI->hasDebugInfo())
1156 return;
1157
1158 unsigned NumDebugCUs = std::distance(M->debug_compile_units_begin(),
1159 M->debug_compile_units_end());
1160 assert(NumDebugCUs > 0 && "Asm unexpectedly initialized")((void)0);
1161 assert(MMI->hasDebugInfo() &&((void)0)
1162 "DebugInfoAvailabilty unexpectedly not initialized")((void)0);
1163 SingleCU = NumDebugCUs == 1;
1164 DenseMap<DIGlobalVariable *, SmallVector<DwarfCompileUnit::GlobalExpr, 1>>
1165 GVMap;
1166 for (const GlobalVariable &Global : M->globals()) {
1167 SmallVector<DIGlobalVariableExpression *, 1> GVs;
1168 Global.getDebugInfo(GVs);
1169 for (auto *GVE : GVs)
1170 GVMap[GVE->getVariable()].push_back({&Global, GVE->getExpression()});
1171 }
1172
1173 // Create the symbol that designates the start of the unit's contribution
1174 // to the string offsets table. In a split DWARF scenario, only the skeleton
1175 // unit has the DW_AT_str_offsets_base attribute (and hence needs the symbol).
1176 if (useSegmentedStringOffsetsTable())
1177 (useSplitDwarf() ? SkeletonHolder : InfoHolder)
1178 .setStringOffsetsStartSym(Asm->createTempSymbol("str_offsets_base"));
1179
1180
1181 // Create the symbols that designates the start of the DWARF v5 range list
1182 // and locations list tables. They are located past the table headers.
1183 if (getDwarfVersion() >= 5) {
1184 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1185 Holder.setRnglistsTableBaseSym(
1186 Asm->createTempSymbol("rnglists_table_base"));
1187
1188 if (useSplitDwarf())
1189 InfoHolder.setRnglistsTableBaseSym(
1190 Asm->createTempSymbol("rnglists_dwo_table_base"));
1191 }
1192
1193 // Create the symbol that points to the first entry following the debug
1194 // address table (.debug_addr) header.
1195 AddrPool.setLabel(Asm->createTempSymbol("addr_table_base"));
1196 DebugLocs.setSym(Asm->createTempSymbol("loclists_table_base"));
1197
1198 for (DICompileUnit *CUNode : M->debug_compile_units()) {
1199 // FIXME: Move local imported entities into a list attached to the
1200 // subprogram, then this search won't be needed and a
1201 // getImportedEntities().empty() test should go below with the rest.
1202 bool HasNonLocalImportedEntities = llvm::any_of(
1203 CUNode->getImportedEntities(), [](const DIImportedEntity *IE) {
1204 return !isa<DILocalScope>(IE->getScope());
1205 });
1206
1207 if (!HasNonLocalImportedEntities && CUNode->getEnumTypes().empty() &&
1208 CUNode->getRetainedTypes().empty() &&
1209 CUNode->getGlobalVariables().empty() && CUNode->getMacros().empty())
1210 continue;
1211
1212 DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(CUNode);
1213
1214 // Global Variables.
1215 for (auto *GVE : CUNode->getGlobalVariables()) {
1216 // Don't bother adding DIGlobalVariableExpressions listed in the CU if we
1217 // already know about the variable and it isn't adding a constant
1218 // expression.
1219 auto &GVMapEntry = GVMap[GVE->getVariable()];
1220 auto *Expr = GVE->getExpression();
1221 if (!GVMapEntry.size() || (Expr && Expr->isConstant()))
1222 GVMapEntry.push_back({nullptr, Expr});
1223 }
1224
1225 DenseSet<DIGlobalVariable *> Processed;
1226 for (auto *GVE : CUNode->getGlobalVariables()) {
1227 DIGlobalVariable *GV = GVE->getVariable();
1228 if (Processed.insert(GV).second)
1229 CU.getOrCreateGlobalVariableDIE(GV, sortGlobalExprs(GVMap[GV]));
1230 }
1231
1232 for (auto *Ty : CUNode->getEnumTypes()) {
1233 // The enum types array by design contains pointers to
1234 // MDNodes rather than DIRefs. Unique them here.
1235 CU.getOrCreateTypeDIE(cast<DIType>(Ty));
1236 }
1237 for (auto *Ty : CUNode->getRetainedTypes()) {
1238 // The retained types array by design contains pointers to
1239 // MDNodes rather than DIRefs. Unique them here.
1240 if (DIType *RT = dyn_cast<DIType>(Ty))
1241 // There is no point in force-emitting a forward declaration.
1242 CU.getOrCreateTypeDIE(RT);
1243 }
1244 // Emit imported_modules last so that the relevant context is already
1245 // available.
1246 for (auto *IE : CUNode->getImportedEntities())
1247 constructAndAddImportedEntityDIE(CU, IE);
1248 }
1249}
1250
1251void DwarfDebug::finishEntityDefinitions() {
1252 for (const auto &Entity : ConcreteEntities) {
1253 DIE *Die = Entity->getDIE();
1254 assert(Die)((void)0);
1255 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
1256 // in the ConcreteEntities list, rather than looking it up again here.
1257 // DIE::getUnit isn't simple - it walks parent pointers, etc.
1258 DwarfCompileUnit *Unit = CUDieMap.lookup(Die->getUnitDie());
1259 assert(Unit)((void)0);
1260 Unit->finishEntityDefinition(Entity.get());
1261 }
1262}
1263
1264void DwarfDebug::finishSubprogramDefinitions() {
1265 for (const DISubprogram *SP : ProcessedSPNodes) {
1266 assert(SP->getUnit()->getEmissionKind() != DICompileUnit::NoDebug)((void)0);
1267 forBothCUs(
1268 getOrCreateDwarfCompileUnit(SP->getUnit()),
1269 [&](DwarfCompileUnit &CU) { CU.finishSubprogramDefinition(SP); });
1270 }
1271}
1272
1273void DwarfDebug::finalizeModuleInfo() {
1274 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1275
1276 finishSubprogramDefinitions();
1277
1278 finishEntityDefinitions();
1279
1280 // Include the DWO file name in the hash if there's more than one CU.
1281 // This handles ThinLTO's situation where imported CUs may very easily be
1282 // duplicate with the same CU partially imported into another ThinLTO unit.
1283 StringRef DWOName;
1284 if (CUMap.size() > 1)
1285 DWOName = Asm->TM.Options.MCOptions.SplitDwarfFile;
1286
1287 // Handle anything that needs to be done on a per-unit basis after
1288 // all other generation.
1289 for (const auto &P : CUMap) {
1290 auto &TheCU = *P.second;
1291 if (TheCU.getCUNode()->isDebugDirectivesOnly())
1292 continue;
1293 // Emit DW_AT_containing_type attribute to connect types with their
1294 // vtable holding type.
1295 TheCU.constructContainingTypeDIEs();
1296
1297 // Add CU specific attributes if we need to add any.
1298 // If we're splitting the dwarf out now that we've got the entire
1299 // CU then add the dwo id to it.
1300 auto *SkCU = TheCU.getSkeleton();
1301
1302 bool HasSplitUnit = SkCU && !TheCU.getUnitDie().children().empty();
1303
1304 if (HasSplitUnit) {
1305 dwarf::Attribute attrDWOName = getDwarfVersion() >= 5
1306 ? dwarf::DW_AT_dwo_name
1307 : dwarf::DW_AT_GNU_dwo_name;
1308 finishUnitAttributes(TheCU.getCUNode(), TheCU);
1309 TheCU.addString(TheCU.getUnitDie(), attrDWOName,
1310 Asm->TM.Options.MCOptions.SplitDwarfFile);
1311 SkCU->addString(SkCU->getUnitDie(), attrDWOName,
1312 Asm->TM.Options.MCOptions.SplitDwarfFile);
1313 // Emit a unique identifier for this CU.
1314 uint64_t ID =
1315 DIEHash(Asm, &TheCU).computeCUSignature(DWOName, TheCU.getUnitDie());
1316 if (getDwarfVersion() >= 5) {
1317 TheCU.setDWOId(ID);
1318 SkCU->setDWOId(ID);
1319 } else {
1320 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
1321 dwarf::DW_FORM_data8, ID);
1322 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
1323 dwarf::DW_FORM_data8, ID);
1324 }
1325
1326 if (getDwarfVersion() < 5 && !SkeletonHolder.getRangeLists().empty()) {
1327 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
1328 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
1329 Sym, Sym);
1330 }
1331 } else if (SkCU) {
1332 finishUnitAttributes(SkCU->getCUNode(), *SkCU);
1333 }
1334
1335 // If we have code split among multiple sections or non-contiguous
1336 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
1337 // remain in the .o file, otherwise add a DW_AT_low_pc.
1338 // FIXME: We should use ranges allow reordering of code ala
1339 // .subsections_via_symbols in mach-o. This would mean turning on
1340 // ranges for all subprogram DIEs for mach-o.
1341 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
1342
1343 if (unsigned NumRanges = TheCU.getRanges().size()) {
1344 if (NumRanges > 1 && useRangesSection())
1345 // A DW_AT_low_pc attribute may also be specified in combination with
1346 // DW_AT_ranges to specify the default base address for use in
1347 // location lists (see Section 2.6.2) and range lists (see Section
1348 // 2.17.3).
1349 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
1350 else
1351 U.setBaseAddress(TheCU.getRanges().front().Begin);
1352 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
1353 }
1354
1355 // We don't keep track of which addresses are used in which CU so this
1356 // is a bit pessimistic under LTO.
1357 if ((HasSplitUnit || getDwarfVersion() >= 5) && !AddrPool.isEmpty())
1358 U.addAddrTableBase();
1359
1360 if (getDwarfVersion() >= 5) {
1361 if (U.hasRangeLists())
1362 U.addRnglistsBase();
1363
1364 if (!DebugLocs.getLists().empty()) {
1365 if (!useSplitDwarf())
1366 U.addSectionLabel(U.getUnitDie(), dwarf::DW_AT_loclists_base,
1367 DebugLocs.getSym(),
1368 TLOF.getDwarfLoclistsSection()->getBeginSymbol());
1369 }
1370 }
1371
1372 auto *CUNode = cast<DICompileUnit>(P.first);
1373 // If compile Unit has macros, emit "DW_AT_macro_info/DW_AT_macros"
1374 // attribute.
1375 if (CUNode->getMacros()) {
1376 if (UseDebugMacroSection) {
1377 if (useSplitDwarf())
1378 TheCU.addSectionDelta(
1379 TheCU.getUnitDie(), dwarf::DW_AT_macros, U.getMacroLabelBegin(),
1380 TLOF.getDwarfMacroDWOSection()->getBeginSymbol());
1381 else {
1382 dwarf::Attribute MacrosAttr = getDwarfVersion() >= 5
1383 ? dwarf::DW_AT_macros
1384 : dwarf::DW_AT_GNU_macros;
1385 U.addSectionLabel(U.getUnitDie(), MacrosAttr, U.getMacroLabelBegin(),
1386 TLOF.getDwarfMacroSection()->getBeginSymbol());
1387 }
1388 } else {
1389 if (useSplitDwarf())
1390 TheCU.addSectionDelta(
1391 TheCU.getUnitDie(), dwarf::DW_AT_macro_info,
1392 U.getMacroLabelBegin(),
1393 TLOF.getDwarfMacinfoDWOSection()->getBeginSymbol());
1394 else
1395 U.addSectionLabel(U.getUnitDie(), dwarf::DW_AT_macro_info,
1396 U.getMacroLabelBegin(),
1397 TLOF.getDwarfMacinfoSection()->getBeginSymbol());
1398 }
1399 }
1400 }
1401
1402 // Emit all frontend-produced Skeleton CUs, i.e., Clang modules.
1403 for (auto *CUNode : MMI->getModule()->debug_compile_units())
1404 if (CUNode->getDWOId())
1405 getOrCreateDwarfCompileUnit(CUNode);
1406
1407 // Compute DIE offsets and sizes.
1408 InfoHolder.computeSizeAndOffsets();
1409 if (useSplitDwarf())
1410 SkeletonHolder.computeSizeAndOffsets();
1411}
1412
1413// Emit all Dwarf sections that should come after the content.
1414void DwarfDebug::endModule() {
1415 assert(CurFn == nullptr)((void)0);
1416 assert(CurMI == nullptr)((void)0);
1417
1418 for (const auto &P : CUMap) {
1419 auto &CU = *P.second;
1420 CU.createBaseTypeDIEs();
1421 }
1422
1423 // If we aren't actually generating debug info (check beginModule -
1424 // conditionalized on the presence of the llvm.dbg.cu metadata node)
1425 if (!Asm || !MMI->hasDebugInfo())
1426 return;
1427
1428 // Finalize the debug info for the module.
1429 finalizeModuleInfo();
1430
1431 if (useSplitDwarf())
1432 // Emit debug_loc.dwo/debug_loclists.dwo section.
1433 emitDebugLocDWO();
1434 else
1435 // Emit debug_loc/debug_loclists section.
1436 emitDebugLoc();
1437
1438 // Corresponding abbreviations into a abbrev section.
1439 emitAbbreviations();
1440
1441 // Emit all the DIEs into a debug info section.
1442 emitDebugInfo();
1443
1444 // Emit info into a debug aranges section.
1445 if (GenerateARangeSection)
1446 emitDebugARanges();
1447
1448 // Emit info into a debug ranges section.
1449 emitDebugRanges();
1450
1451 if (useSplitDwarf())
1452 // Emit info into a debug macinfo.dwo section.
1453 emitDebugMacinfoDWO();
1454 else
1455 // Emit info into a debug macinfo/macro section.
1456 emitDebugMacinfo();
1457
1458 emitDebugStr();
1459
1460 if (useSplitDwarf()) {
1461 emitDebugStrDWO();
1462 emitDebugInfoDWO();
1463 emitDebugAbbrevDWO();
1464 emitDebugLineDWO();
1465 emitDebugRangesDWO();
1466 }
1467
1468 emitDebugAddr();
1469
1470 // Emit info into the dwarf accelerator table sections.
1471 switch (getAccelTableKind()) {
1472 case AccelTableKind::Apple:
1473 emitAccelNames();
1474 emitAccelObjC();
1475 emitAccelNamespaces();
1476 emitAccelTypes();
1477 break;
1478 case AccelTableKind::Dwarf:
1479 emitAccelDebugNames();
1480 break;
1481 case AccelTableKind::None:
1482 break;
1483 case AccelTableKind::Default:
1484 llvm_unreachable("Default should have already been resolved.")__builtin_unreachable();
1485 }
1486
1487 // Emit the pubnames and pubtypes sections if requested.
1488 emitDebugPubSections();
1489
1490 // clean up.
1491 // FIXME: AbstractVariables.clear();
1492}
1493
1494void DwarfDebug::ensureAbstractEntityIsCreated(DwarfCompileUnit &CU,
1495 const DINode *Node,
1496 const MDNode *ScopeNode) {
1497 if (CU.getExistingAbstractEntity(Node))
1498 return;
1499
1500 CU.createAbstractEntity(Node, LScopes.getOrCreateAbstractScope(
1501 cast<DILocalScope>(ScopeNode)));
1502}
1503
1504void DwarfDebug::ensureAbstractEntityIsCreatedIfScoped(DwarfCompileUnit &CU,
1505 const DINode *Node, const MDNode *ScopeNode) {
1506 if (CU.getExistingAbstractEntity(Node))
1507 return;
1508
1509 if (LexicalScope *Scope =
1510 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
1511 CU.createAbstractEntity(Node, Scope);
1512}
1513
1514// Collect variable information from side table maintained by MF.
1515void DwarfDebug::collectVariableInfoFromMFTable(
1516 DwarfCompileUnit &TheCU, DenseSet<InlinedEntity> &Processed) {
1517 SmallDenseMap<InlinedEntity, DbgVariable *> MFVars;
1518 LLVM_DEBUG(dbgs() << "DwarfDebug: collecting variables from MF side table\n")do { } while (false);
1519 for (const auto &VI : Asm->MF->getVariableDbgInfo()) {
1520 if (!VI.Var)
1521 continue;
1522 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&((void)0)
1523 "Expected inlined-at fields to agree")((void)0);
1524
1525 InlinedEntity Var(VI.Var, VI.Loc->getInlinedAt());
1526 Processed.insert(Var);
1527 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1528
1529 // If variable scope is not found then skip this variable.
1530 if (!Scope) {
1531 LLVM_DEBUG(dbgs() << "Dropping debug info for " << VI.Var->getName()do { } while (false)
1532 << ", no variable scope found\n")do { } while (false);
1533 continue;
1534 }
1535
1536 ensureAbstractEntityIsCreatedIfScoped(TheCU, Var.first, Scope->getScopeNode());
1537 auto RegVar = std::make_unique<DbgVariable>(
1538 cast<DILocalVariable>(Var.first), Var.second);
1539 RegVar->initializeMMI(VI.Expr, VI.Slot);
1540 LLVM_DEBUG(dbgs() << "Created DbgVariable for " << VI.Var->getName()do { } while (false)
1541 << "\n")do { } while (false);
1542
1543 if (DbgVariable *DbgVar = MFVars.lookup(Var))
1544 DbgVar->addMMIEntry(*RegVar);
1545 else if (InfoHolder.addScopeVariable(Scope, RegVar.get())) {
1546 MFVars.insert({Var, RegVar.get()});
1547 ConcreteEntities.push_back(std::move(RegVar));
1548 }
1549 }
1550}
1551
1552/// Determine whether a *singular* DBG_VALUE is valid for the entirety of its
1553/// enclosing lexical scope. The check ensures there are no other instructions
1554/// in the same lexical scope preceding the DBG_VALUE and that its range is
1555/// either open or otherwise rolls off the end of the scope.
1556static bool validThroughout(LexicalScopes &LScopes,
1557 const MachineInstr *DbgValue,
1558 const MachineInstr *RangeEnd,
1559 const InstructionOrdering &Ordering) {
1560 assert(DbgValue->getDebugLoc() && "DBG_VALUE without a debug location")((void)0);
1561 auto MBB = DbgValue->getParent();
24
←
Called C++ object pointer is null
1562 auto DL = DbgValue->getDebugLoc();
1563 auto *LScope = LScopes.findLexicalScope(DL);
1564 // Scope doesn't exist; this is a dead DBG_VALUE.
1565 if (!LScope)
1566 return false;
1567 auto &LSRange = LScope->getRanges();
1568 if (LSRange.size() == 0)
1569 return false;
1570
1571 const MachineInstr *LScopeBegin = LSRange.front().first;
1572 // If the scope starts before the DBG_VALUE then we may have a negative
1573 // result. Otherwise the location is live coming into the scope and we
1574 // can skip the following checks.
1575 if (!Ordering.isBefore(DbgValue, LScopeBegin)) {
1576 // Exit if the lexical scope begins outside of the current block.
1577 if (LScopeBegin->getParent() != MBB)
1578 return false;
1579
1580 MachineBasicBlock::const_reverse_iterator Pred(DbgValue);
1581 for (++Pred; Pred != MBB->rend(); ++Pred) {
1582 if (Pred->getFlag(MachineInstr::FrameSetup))
1583 break;
1584 auto PredDL = Pred->getDebugLoc();
1585 if (!PredDL || Pred->isMetaInstruction())
1586 continue;
1587 // Check whether the instruction preceding the DBG_VALUE is in the same
1588 // (sub)scope as the DBG_VALUE.
1589 if (DL->getScope() == PredDL->getScope())
1590 return false;
1591 auto *PredScope = LScopes.findLexicalScope(PredDL);
1592 if (!PredScope || LScope->dominates(PredScope))
1593 return false;
1594 }
1595 }
1596
1597 // If the range of the DBG_VALUE is open-ended, report success.
1598 if (!RangeEnd)
1599 return true;
1600
1601 // Single, constant DBG_VALUEs in the prologue are promoted to be live
1602 // throughout the function. This is a hack, presumably for DWARF v2 and not
1603 // necessarily correct. It would be much better to use a dbg.declare instead
1604 // if we know the constant is live throughout the scope.
1605 if (MBB->pred_empty() &&
1606 all_of(DbgValue->debug_operands(),
1607 [](const MachineOperand &Op) { return Op.isImm(); }))
1608 return true;
1609
1610 // Test if the location terminates before the end of the scope.
1611 const MachineInstr *LScopeEnd = LSRange.back().second;
1612 if (Ordering.isBefore(RangeEnd, LScopeEnd))
1613 return false;
1614
1615 // There's a single location which starts at the scope start, and ends at or
1616 // after the scope end.
1617 return true;
1618}
1619
1620/// Build the location list for all DBG_VALUEs in the function that
1621/// describe the same variable. The resulting DebugLocEntries will have
1622/// strict monotonically increasing begin addresses and will never
1623/// overlap. If the resulting list has only one entry that is valid
1624/// throughout variable's scope return true.
1625//
1626// See the definition of DbgValueHistoryMap::Entry for an explanation of the
1627// different kinds of history map entries. One thing to be aware of is that if
1628// a debug value is ended by another entry (rather than being valid until the
1629// end of the function), that entry's instruction may or may not be included in
1630// the range, depending on if the entry is a clobbering entry (it has an
1631// instruction that clobbers one or more preceding locations), or if it is an
1632// (overlapping) debug value entry. This distinction can be seen in the example
1633// below. The first debug value is ended by the clobbering entry 2, and the
1634// second and third debug values are ended by the overlapping debug value entry
1635// 4.
1636//
1637// Input:
1638//
1639// History map entries [type, end index, mi]
1640//
1641// 0 | [DbgValue, 2, DBG_VALUE $reg0, [...] (fragment 0, 32)]
1642// 1 | | [DbgValue, 4, DBG_VALUE $reg1, [...] (fragment 32, 32)]
1643// 2 | | [Clobber, $reg0 = [...], -, -]
1644// 3 | | [DbgValue, 4, DBG_VALUE 123, [...] (fragment 64, 32)]
1645// 4 [DbgValue, ~0, DBG_VALUE @g, [...] (fragment 0, 96)]
1646//
1647// Output [start, end) [Value...]:
1648//
1649// [0-1) [(reg0, fragment 0, 32)]
1650// [1-3) [(reg0, fragment 0, 32), (reg1, fragment 32, 32)]
1651// [3-4) [(reg1, fragment 32, 32), (123, fragment 64, 32)]
1652// [4-) [(@g, fragment 0, 96)]
1653bool DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1654 const DbgValueHistoryMap::Entries &Entries) {
1655 using OpenRange =
1656 std::pair<DbgValueHistoryMap::EntryIndex, DbgValueLoc>;
1657 SmallVector<OpenRange, 4> OpenRanges;
1658 bool isSafeForSingleLocation = true;
1659 const MachineInstr *StartDebugMI = nullptr;
19
←
'StartDebugMI' initialized to a null pointer value
→
1660 const MachineInstr *EndMI = nullptr;
1661
1662 for (auto EB = Entries.begin(), EI = EB, EE = Entries.end(); EI != EE; ++EI) {
20
←
Assuming 'EI' is equal to 'EE'
→
21
←
Loop condition is false. Execution continues on line 1771
→
1663 const MachineInstr *Instr = EI->getInstr();
1664
1665 // Remove all values that are no longer live.
1666 size_t Index = std::distance(EB, EI);
1667 erase_if(OpenRanges, [&](OpenRange &R) { return R.first <= Index; });
1668
1669 // If we are dealing with a clobbering entry, this iteration will result in
1670 // a location list entry starting after the clobbering instruction.
1671 const MCSymbol *StartLabel =
1672 EI->isClobber() ? getLabelAfterInsn(Instr) : getLabelBeforeInsn(Instr);
1673 assert(StartLabel &&((void)0)
1674 "Forgot label before/after instruction starting a range!")((void)0);
1675
1676 const MCSymbol *EndLabel;
1677 if (std::next(EI) == Entries.end()) {
1678 const MachineBasicBlock &EndMBB = Asm->MF->back();
1679 EndLabel = Asm->MBBSectionRanges[EndMBB.getSectionIDNum()].EndLabel;
1680 if (EI->isClobber())
1681 EndMI = EI->getInstr();
1682 }
1683 else if (std::next(EI)->isClobber())
1684 EndLabel = getLabelAfterInsn(std::next(EI)->getInstr());
1685 else
1686 EndLabel = getLabelBeforeInsn(std::next(EI)->getInstr());
1687 assert(EndLabel && "Forgot label after instruction ending a range!")((void)0);
1688
1689 if (EI->isDbgValue())
1690 LLVM_DEBUG(dbgs() << "DotDebugLoc: " << *Instr << "\n")do { } while (false);
1691
1692 // If this history map entry has a debug value, add that to the list of
1693 // open ranges and check if its location is valid for a single value
1694 // location.
1695 if (EI->isDbgValue()) {
1696 // Do not add undef debug values, as they are redundant information in
1697 // the location list entries. An undef debug results in an empty location
1698 // description. If there are any non-undef fragments then padding pieces
1699 // with empty location descriptions will automatically be inserted, and if
1700 // all fragments are undef then the whole location list entry is
1701 // redundant.
1702 if (!Instr->isUndefDebugValue()) {
1703 auto Value = getDebugLocValue(Instr);
1704 OpenRanges.emplace_back(EI->getEndIndex(), Value);
1705
1706 // TODO: Add support for single value fragment locations.
1707 if (Instr->getDebugExpression()->isFragment())
1708 isSafeForSingleLocation = false;
1709
1710 if (!StartDebugMI)
1711 StartDebugMI = Instr;
1712 } else {
1713 isSafeForSingleLocation = false;
1714 }
1715 }
1716
1717 // Location list entries with empty location descriptions are redundant
1718 // information in DWARF, so do not emit those.
1719 if (OpenRanges.empty())
1720 continue;
1721
1722 // Omit entries with empty ranges as they do not have any effect in DWARF.
1723 if (StartLabel == EndLabel) {
1724 LLVM_DEBUG(dbgs() << "Omitting location list entry with empty range.\n")do { } while (false);
1725 continue;
1726 }
1727
1728 SmallVector<DbgValueLoc, 4> Values;
1729 for (auto &R : OpenRanges)
1730 Values.push_back(R.second);
1731
1732 // With Basic block sections, it is posssible that the StartLabel and the
1733 // Instr are not in the same section. This happens when the StartLabel is
1734 // the function begin label and the dbg value appears in a basic block
1735 // that is not the entry. In this case, the range needs to be split to
1736 // span each individual section in the range from StartLabel to EndLabel.
1737 if (Asm->MF->hasBBSections() && StartLabel == Asm->getFunctionBegin() &&
1738 !Instr->getParent()->sameSection(&Asm->MF->front())) {
1739 const MCSymbol *BeginSectionLabel = StartLabel;
1740
1741 for (const MachineBasicBlock &MBB : *Asm->MF) {
1742 if (MBB.isBeginSection() && &MBB != &Asm->MF->front())
1743 BeginSectionLabel = MBB.getSymbol();
1744
1745 if (MBB.sameSection(Instr->getParent())) {
1746 DebugLoc.emplace_back(BeginSectionLabel, EndLabel, Values);
1747 break;
1748 }
1749 if (MBB.isEndSection())
1750 DebugLoc.emplace_back(BeginSectionLabel, MBB.getEndSymbol(), Values);
1751 }
1752 } else {
1753 DebugLoc.emplace_back(StartLabel, EndLabel, Values);
1754 }
1755
1756 // Attempt to coalesce the ranges of two otherwise identical
1757 // DebugLocEntries.
1758 auto CurEntry = DebugLoc.rbegin();
1759 LLVM_DEBUG({do { } while (false)
1760 dbgs() << CurEntry->getValues().size() << " Values:\n";do { } while (false)
1761 for (auto &Value : CurEntry->getValues())do { } while (false)
1762 Value.dump();do { } while (false)
1763 dbgs() << "-----\n";do { } while (false)
1764 })do { } while (false);
1765
1766 auto PrevEntry = std::next(CurEntry);
1767 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1768 DebugLoc.pop_back();
1769 }
1770
1771 if (!isSafeForSingleLocation
21.1
'isSafeForSingleLocation' is true
 ||
1772 !validThroughout(LScopes, StartDebugMI, EndMI, getInstOrdering()))
22
←
Passing null pointer value via 2nd parameter 'DbgValue'
→
23
←
Calling 'validThroughout'
→
1773 return false;
1774
1775 if (DebugLoc.size() == 1)
1776 return true;
1777
1778 if (!Asm->MF->hasBBSections())
1779 return false;
1780
1781 // Check here to see if loclist can be merged into a single range. If not,
1782 // we must keep the split loclists per section. This does exactly what
1783 // MergeRanges does without sections. We don't actually merge the ranges
1784 // as the split ranges must be kept intact if this cannot be collapsed
1785 // into a single range.
1786 const MachineBasicBlock *RangeMBB = nullptr;
1787 if (DebugLoc[0].getBeginSym() == Asm->getFunctionBegin())
1788 RangeMBB = &Asm->MF->front();
1789 else
1790 RangeMBB = Entries.begin()->getInstr()->getParent();
1791 auto *CurEntry = DebugLoc.begin();
1792 auto *NextEntry = std::next(CurEntry);
1793 while (NextEntry != DebugLoc.end()) {
1794 // Get the last machine basic block of this section.
1795 while (!RangeMBB->isEndSection())
1796 RangeMBB = RangeMBB->getNextNode();
1797 if (!RangeMBB->getNextNode())
1798 return false;
1799 // CurEntry should end the current section and NextEntry should start
1800 // the next section and the Values must match for these two ranges to be
1801 // merged.
1802 if (CurEntry->getEndSym() != RangeMBB->getEndSymbol() ||
1803 NextEntry->getBeginSym() != RangeMBB->getNextNode()->getSymbol() ||
1804 CurEntry->getValues() != NextEntry->getValues())
1805 return false;
1806 RangeMBB = RangeMBB->getNextNode();
1807 CurEntry = NextEntry;
1808 NextEntry = std::next(CurEntry);
1809 }
1810 return true;
1811}
1812
1813DbgEntity *DwarfDebug::createConcreteEntity(DwarfCompileUnit &TheCU,
1814 LexicalScope &Scope,
1815 const DINode *Node,
1816 const DILocation *Location,
1817 const MCSymbol *Sym) {
1818 ensureAbstractEntityIsCreatedIfScoped(TheCU, Node, Scope.getScopeNode());
1819 if (isa<const DILocalVariable>(Node)) {
1820 ConcreteEntities.push_back(
1821 std::make_unique<DbgVariable>(cast<const DILocalVariable>(Node),
1822 Location));
1823 InfoHolder.addScopeVariable(&Scope,
1824 cast<DbgVariable>(ConcreteEntities.back().get()));
1825 } else if (isa<const DILabel>(Node)) {
1826 ConcreteEntities.push_back(
1827 std::make_unique<DbgLabel>(cast<const DILabel>(Node),
1828 Location, Sym));
1829 InfoHolder.addScopeLabel(&Scope,
1830 cast<DbgLabel>(ConcreteEntities.back().get()));
1831 }
1832 return ConcreteEntities.back().get();
1833}
1834
1835// Find variables for each lexical scope.
1836void DwarfDebug::collectEntityInfo(DwarfCompileUnit &TheCU,
1837 const DISubprogram *SP,
1838 DenseSet<InlinedEntity> &Processed) {
1839 // Grab the variable info that was squirreled away in the MMI side-table.
1840 collectVariableInfoFromMFTable(TheCU, Processed);
1841
1842 for (const auto &I : DbgValues) {
1843 InlinedEntity IV = I.first;
1844 if (Processed.count(IV))
3
←
Assuming the condition is false
→
4
←
Taking false branch
→
1845 continue;
1846
1847 // Instruction ranges, specifying where IV is accessible.
1848 const auto &HistoryMapEntries = I.second;
1849
1850 // Try to find any non-empty variable location. Do not create a concrete
1851 // entity if there are no locations.
1852 if (!DbgValues.hasNonEmptyLocation(HistoryMapEntries))
5
←
Assuming the condition is false
→
6
←
Taking false branch
→
1853 continue;
1854
1855 LexicalScope *Scope = nullptr;
1856 const DILocalVariable *LocalVar = cast<DILocalVariable>(IV.first);
7
←
Field 'first' is a 'DILocalVariable'
→
1857 if (const DILocation *IA = IV.second)
8
←
Assuming 'IA' is null
→
9
←
Taking false branch
→
1858 Scope = LScopes.findInlinedScope(LocalVar->getScope(), IA);
1859 else
1860 Scope = LScopes.findLexicalScope(LocalVar->getScope());
1861 // If variable scope is not found then skip this variable.
1862 if (!Scope)
10
←
Assuming 'Scope' is non-null
→
11
←
Taking false branch
→
1863 continue;
1864
1865 Processed.insert(IV);
1866 DbgVariable *RegVar = cast<DbgVariable>(createConcreteEntity(TheCU,
12
←
The object is a 'DbgVariable'
→
1867 *Scope, LocalVar, IV.second));
1868
1869 const MachineInstr *MInsn = HistoryMapEntries.front().getInstr();
1870 assert(MInsn->isDebugValue() && "History must begin with debug value")((void)0);
1871
1872 // Check if there is a single DBG_VALUE, valid throughout the var's scope.
1873 // If the history map contains a single debug value, there may be an
1874 // additional entry which clobbers the debug value.
1875 size_t HistSize = HistoryMapEntries.size();
1876 bool SingleValueWithClobber =
1877 HistSize == 2 && HistoryMapEntries[1].isClobber();
13
←
Assuming 'HistSize' is not equal to 2
→
1878 if (HistSize == 1 || SingleValueWithClobber
14.1
'SingleValueWithClobber' is false
) {
14
←
Assuming 'HistSize' is not equal to 1
→
15
←
Taking false branch
→
1879 const auto *End =
1880 SingleValueWithClobber ? HistoryMapEntries[1].getInstr() : nullptr;
1881 if (validThroughout(LScopes, MInsn, End, getInstOrdering())) {
1882 RegVar->initializeDbgValue(MInsn);
1883 continue;
1884 }
1885 }
1886
1887 // Do not emit location lists if .debug_loc secton is disabled.
1888 if (!useLocSection())
16
←
Assuming the condition is false
→
17
←
Taking false branch
→
1889 continue;
1890
1891 // Handle multiple DBG_VALUE instructions describing one variable.
1892 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
1893
1894 // Build the location list for this variable.
1895 SmallVector<DebugLocEntry, 8> Entries;
1896 bool isValidSingleLocation = buildLocationList(Entries, HistoryMapEntries);
18
←
Calling 'DwarfDebug::buildLocationList'
→
1897
1898 // Check whether buildLocationList managed to merge all locations to one
1899 // that is valid throughout the variable's scope. If so, produce single
1900 // value location.
1901 if (isValidSingleLocation) {
1902 RegVar->initializeDbgValue(Entries[0].getValues()[0]);
1903 continue;
1904 }
1905
1906 // If the variable has a DIBasicType, extract it. Basic types cannot have
1907 // unique identifiers, so don't bother resolving the type with the
1908 // identifier map.
1909 const DIBasicType *BT = dyn_cast<DIBasicType>(
1910 static_cast<const Metadata *>(LocalVar->getType()));
1911
1912 // Finalize the entry by lowering it into a DWARF bytestream.
1913 for (auto &Entry : Entries)
1914 Entry.finalize(*Asm, List, BT, TheCU);
1915 }
1916
1917 // For each InlinedEntity collected from DBG_LABEL instructions, convert to
1918 // DWARF-related DbgLabel.
1919 for (const auto &I : DbgLabels) {
1920 InlinedEntity IL = I.first;
1921 const MachineInstr *MI = I.second;
1922 if (MI == nullptr)
1923 continue;
1924
1925 LexicalScope *Scope = nullptr;
1926 const DILabel *Label = cast<DILabel>(IL.first);
1927 // The scope could have an extra lexical block file.
1928 const DILocalScope *LocalScope =
1929 Label->getScope()->getNonLexicalBlockFileScope();
1930 // Get inlined DILocation if it is inlined label.
1931 if (const DILocation *IA = IL.second)
1932 Scope = LScopes.findInlinedScope(LocalScope, IA);
1933 else
1934 Scope = LScopes.findLexicalScope(LocalScope);
1935 // If label scope is not found then skip this label.
1936 if (!Scope)
1937 continue;
1938
1939 Processed.insert(IL);
1940 /// At this point, the temporary label is created.
1941 /// Save the temporary label to DbgLabel entity to get the
1942 /// actually address when generating Dwarf DIE.
1943 MCSymbol *Sym = getLabelBeforeInsn(MI);
1944 createConcreteEntity(TheCU, *Scope, Label, IL.second, Sym);
1945 }
1946
1947 // Collect info for variables/labels that were optimized out.
1948 for (const DINode *DN : SP->getRetainedNodes()) {
1949 if (!Processed.insert(InlinedEntity(DN, nullptr)).second)
1950 continue;
1951 LexicalScope *Scope = nullptr;
1952 if (auto *DV = dyn_cast<DILocalVariable>(DN)) {
1953 Scope = LScopes.findLexicalScope(DV->getScope());
1954 } else if (auto *DL = dyn_cast<DILabel>(DN)) {
1955 Scope = LScopes.findLexicalScope(DL->getScope());
1956 }
1957
1958 if (Scope)
1959 createConcreteEntity(TheCU, *Scope, DN, nullptr);
1960 }
1961}
1962
1963// Process beginning of an instruction.
1964void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1965 const MachineFunction &MF = *MI->getMF();
1966 const auto *SP = MF.getFunction().getSubprogram();
1967 bool NoDebug =
1968 !SP || SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug;
1969
1970 // Delay slot support check.
1971 auto delaySlotSupported = [](const MachineInstr &MI) {
1972 if (!MI.isBundledWithSucc())
1973 return false;
1974 auto Suc = std::next(MI.getIterator());
1975 (void)Suc;
1976 // Ensure that delay slot instruction is successor of the call instruction.
1977 // Ex. CALL_INSTRUCTION {
1978 // DELAY_SLOT_INSTRUCTION }
1979 assert(Suc->isBundledWithPred() &&((void)0)
1980 "Call bundle instructions are out of order")((void)0);
1981 return true;
1982 };
1983
1984 // When describing calls, we need a label for the call instruction.
1985 if (!NoDebug && SP->areAllCallsDescribed() &&
1986 MI->isCandidateForCallSiteEntry(MachineInstr::AnyInBundle) &&
1987 (!MI->hasDelaySlot() || delaySlotSupported(*MI))) {
1988 const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
1989 bool IsTail = TII->isTailCall(*MI);
1990 // For tail calls, we need the address of the branch instruction for
1991 // DW_AT_call_pc.
1992 if (IsTail)
1993 requestLabelBeforeInsn(MI);
1994 // For non-tail calls, we need the return address for the call for
1995 // DW_AT_call_return_pc. Under GDB tuning, this information is needed for
1996 // tail calls as well.
1997 requestLabelAfterInsn(MI);
1998 }
1999
2000 DebugHandlerBase::beginInstruction(MI);
2001 if (!CurMI)
2002 return;
2003
2004 if (NoDebug)
2005 return;
2006
2007 // Check if source location changes, but ignore DBG_VALUE and CFI locations.
2008 // If the instruction is part of the function frame setup code, do not emit
2009 // any line record, as there is no correspondence with any user code.
2010 if (MI->isMetaInstruction() || MI->getFlag(MachineInstr::FrameSetup))
2011 return;
2012 const DebugLoc &DL = MI->getDebugLoc();
2013 // When we emit a line-0 record, we don't update PrevInstLoc; so look at
2014 // the last line number actually emitted, to see if it was line 0.
2015 unsigned LastAsmLine =
2016 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine();
2017
2018 if (DL == PrevInstLoc) {
2019 // If we have an ongoing unspecified location, nothing to do here.
2020 if (!DL)
2021 return;
2022 // We have an explicit location, same as the previous location.
2023 // But we might be coming back to it after a line 0 record.
2024 if (LastAsmLine == 0 && DL.getLine() != 0) {
2025 // Reinstate the source location but not marked as a statement.
2026 const MDNode *Scope = DL.getScope();
2027 recordSourceLine(DL.getLine(), DL.getCol(), Scope, /*Flags=*/0);
2028 }
2029 return;
2030 }
2031
2032 if (!DL) {
2033 // We have an unspecified location, which might want to be line 0.
2034 // If we have already emitted a line-0 record, don't repeat it.
2035 if (LastAsmLine == 0)
2036 return;
2037 // If user said Don't Do That, don't do that.
2038 if (UnknownLocations == Disable)
2039 return;
2040 // See if we have a reason to emit a line-0 record now.
2041 // Reasons to emit a line-0 record include:
2042 // - User asked for it (UnknownLocations).
2043 // - Instruction has a label, so it's referenced from somewhere else,
2044 // possibly debug information; we want it to have a source location.
2045 // - Instruction is at the top of a block; we don't want to inherit the
2046 // location from the physically previous (maybe unrelated) block.
2047 if (UnknownLocations == Enable || PrevLabel ||
2048 (PrevInstBB && PrevInstBB != MI->getParent())) {
2049 // Preserve the file and column numbers, if we can, to save space in
2050 // the encoded line table.
2051 // Do not update PrevInstLoc, it remembers the last non-0 line.
2052 const MDNode *Scope = nullptr;
2053 unsigned Column = 0;
2054 if (PrevInstLoc) {
2055 Scope = PrevInstLoc.getScope();
2056 Column = PrevInstLoc.getCol();
2057 }
2058 recordSourceLine(/*Line=*/0, Column, Scope, /*Flags=*/0);
2059 }
2060 return;
2061 }
2062
2063 // We have an explicit location, different from the previous location.
2064 // Don't repeat a line-0 record, but otherwise emit the new location.
2065 // (The new location might be an explicit line 0, which we do emit.)
2066 if (DL.getLine() == 0 && LastAsmLine == 0)
2067 return;
2068 unsigned Flags = 0;
2069 if (DL == PrologEndLoc) {
2070 Flags |= DWARF2_FLAG_PROLOGUE_END(1 << 2) | DWARF2_FLAG_IS_STMT(1 << 0);
2071 PrologEndLoc = DebugLoc();
2072 }
2073 // If the line changed, we call that a new statement; unless we went to
2074 // line 0 and came back, in which case it is not a new statement.
2075 unsigned OldLine = PrevInstLoc ? PrevInstLoc.getLine() : LastAsmLine;
2076 if (DL.getLine() && DL.getLine() != OldLine)
2077 Flags |= DWARF2_FLAG_IS_STMT(1 << 0);
2078
2079 const MDNode *Scope = DL.getScope();
2080 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
2081
2082 // If we're not at line 0, remember this location.
2083 if (DL.getLine())
2084 PrevInstLoc = DL;
2085}
2086
2087static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
2088 // First known non-DBG_VALUE and non-frame setup location marks
2089 // the beginning of the function body.
2090 for (const auto &MBB : *MF)
2091 for (const auto &MI : MBB)
2092 if (!MI.isMetaInstruction() && !MI.getFlag(MachineInstr::FrameSetup) &&
2093 MI.getDebugLoc())
2094 return MI.getDebugLoc();
2095 return DebugLoc();
2096}
2097
2098/// Register a source line with debug info. Returns the unique label that was
2099/// emitted and which provides correspondence to the source line list.
2100static void recordSourceLine(AsmPrinter &Asm, unsigned Line, unsigned Col,
2101 const MDNode *S, unsigned Flags, unsigned CUID,
2102 uint16_t DwarfVersion,
2103 ArrayRef<std::unique_ptr<DwarfCompileUnit>> DCUs) {
2104 StringRef Fn;
2105 unsigned FileNo = 1;
2106 unsigned Discriminator = 0;
2107 if (auto *Scope = cast_or_null<DIScope>(S)) {
2108 Fn = Scope->getFilename();
2109 if (Line != 0 && DwarfVersion >= 4)
2110 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
2111 Discriminator = LBF->getDiscriminator();
2112
2113 FileNo = static_cast<DwarfCompileUnit &>(*DCUs[CUID])
2114 .getOrCreateSourceID(Scope->getFile());
2115 }
2116 Asm.OutStreamer->emitDwarfLocDirective(FileNo, Line, Col, Flags, 0,
2117 Discriminator, Fn);
2118}
2119
2120DebugLoc DwarfDebug::emitInitialLocDirective(const MachineFunction &MF,
2121 unsigned CUID) {
2122 // Get beginning of function.
2123 if (DebugLoc PrologEndLoc = findPrologueEndLoc(&MF)) {
2124 // Ensure the compile unit is created if the function is called before
2125 // beginFunction().
2126 (void)getOrCreateDwarfCompileUnit(
2127 MF.getFunction().getSubprogram()->getUnit());
2128 // We'd like to list the prologue as "not statements" but GDB behaves
2129 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
2130 const DISubprogram *SP = PrologEndLoc->getInlinedAtScope()->getSubprogram();
2131 ::recordSourceLine(*Asm, SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT(1 << 0),
2132 CUID, getDwarfVersion(), getUnits());
2133 return PrologEndLoc;
2134 }
2135 return DebugLoc();
2136}
2137
2138// Gather pre-function debug information. Assumes being called immediately
2139// after the function entry point has been emitted.
2140void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
2141 CurFn = MF;
2142
2143 auto *SP = MF->getFunction().getSubprogram();
2144 assert(LScopes.empty() || SP == LScopes.getCurrentFunctionScope()->getScopeNode())((void)0);
2145 if (SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug)
2146 return;
2147
2148 DwarfCompileUnit &CU = getOrCreateDwarfCompileUnit(SP->getUnit());
2149
2150 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
2151 // belongs to so that we add to the correct per-cu line table in the
2152 // non-asm case.
2153 if (Asm->OutStreamer->hasRawTextSupport())
2154 // Use a single line table if we are generating assembly.
2155 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
2156 else
2157 Asm->OutStreamer->getContext().setDwarfCompileUnitID(CU.getUniqueID());
2158
2159 // Record beginning of function.
2160 PrologEndLoc = emitInitialLocDirective(
2161 *MF, Asm->OutStreamer->getContext().getDwarfCompileUnitID());
2162}
2163
2164void DwarfDebug::skippedNonDebugFunction() {
2165 // If we don't have a subprogram for this function then there will be a hole
2166 // in the range information. Keep note of this by setting the previously used
2167 // section to nullptr.
2168 PrevCU = nullptr;
2169 CurFn = nullptr;
2170}
2171
2172// Gather and emit post-function debug information.
2173void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
2174 const DISubprogram *SP = MF->getFunction().getSubprogram();
2175
2176 assert(CurFn == MF &&((void)0)
2177 "endFunction should be called with the same function as beginFunction")((void)0);
2178
2179 // Set DwarfDwarfCompileUnitID in MCContext to default value.
2180 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
2181
2182 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
2183 assert(!FnScope || SP == FnScope->getScopeNode())((void)0);
2184 DwarfCompileUnit &TheCU = *CUMap.lookup(SP->getUnit());
2185 if (TheCU.getCUNode()->isDebugDirectivesOnly()) {
1
Taking false branch
→
2186 PrevLabel = nullptr;
2187 CurFn = nullptr;
2188 return;
2189 }
2190
2191 DenseSet<InlinedEntity> Processed;
2192 collectEntityInfo(TheCU, SP, Processed);
2
←
Calling 'DwarfDebug::collectEntityInfo'
→
2193
2194 // Add the range of this function to the list of ranges for the CU.
2195 // With basic block sections, add ranges for all basic block sections.
2196 for (const auto &R : Asm->MBBSectionRanges)
2197 TheCU.addRange({R.second.BeginLabel, R.second.EndLabel});
2198
2199 // Under -gmlt, skip building the subprogram if there are no inlined
2200 // subroutines inside it. But with -fdebug-info-for-profiling, the subprogram
2201 // is still needed as we need its source location.
2202 if (!TheCU.getCUNode()->getDebugInfoForProfiling() &&
2203 TheCU.getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly &&
2204 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
2205 assert(InfoHolder.getScopeVariables().empty())((void)0);
2206 PrevLabel = nullptr;
2207 CurFn = nullptr;
2208 return;
2209 }
2210
2211#ifndef NDEBUG1
2212 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
2213#endif
2214 // Construct abstract scopes.
2215 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
2216 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
2217 for (const DINode *DN : SP->getRetainedNodes()) {
2218 if (!Processed.insert(InlinedEntity(DN, nullptr)).second)
2219 continue;
2220
2221 const MDNode *Scope = nullptr;
2222 if (auto *DV = dyn_cast<DILocalVariable>(DN))
2223 Scope = DV->getScope();
2224 else if (auto *DL = dyn_cast<DILabel>(DN))
2225 Scope = DL->getScope();
2226 else
2227 llvm_unreachable("Unexpected DI type!")__builtin_unreachable();
2228
2229 // Collect info for variables/labels that were optimized out.
2230 ensureAbstractEntityIsCreated(TheCU, DN, Scope);
2231 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes((void)0)
2232 && "ensureAbstractEntityIsCreated inserted abstract scopes")((void)0);
2233 }
2234 constructAbstractSubprogramScopeDIE(TheCU, AScope);
2235 }
2236
2237 ProcessedSPNodes.insert(SP);
2238 DIE &ScopeDIE = TheCU.constructSubprogramScopeDIE(SP, FnScope);
2239 if (auto *SkelCU = TheCU.getSkeleton())
2240 if (!LScopes.getAbstractScopesList().empty() &&
2241 TheCU.getCUNode()->getSplitDebugInlining())
2242 SkelCU->constructSubprogramScopeDIE(SP, FnScope);
2243
2244 // Construct call site entries.
2245 constructCallSiteEntryDIEs(*SP, TheCU, ScopeDIE, *MF);
2246
2247 // Clear debug info
2248 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
2249 // DbgVariables except those that are also in AbstractVariables (since they
2250 // can be used cross-function)
2251 InfoHolder.getScopeVariables().clear();
2252 InfoHolder.getScopeLabels().clear();
2253 PrevLabel = nullptr;
2254 CurFn = nullptr;
2255}
2256
2257// Register a source line with debug info. Returns the unique label that was
2258// emitted and which provides correspondence to the source line list.
2259void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
2260 unsigned Flags) {
2261 ::recordSourceLine(*Asm, Line, Col, S, Flags,
2262 Asm->OutStreamer->getContext().getDwarfCompileUnitID(),
2263 getDwarfVersion(), getUnits());
2264}
2265
2266//===----------------------------------------------------------------------===//
2267// Emit Methods
2268//===----------------------------------------------------------------------===//
2269
2270// Emit the debug info section.
2271void DwarfDebug::emitDebugInfo() {
2272 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2273 Holder.emitUnits(/* UseOffsets */ false);
2274}
2275
2276// Emit the abbreviation section.
2277void DwarfDebug::emitAbbreviations() {
2278 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2279
2280 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
2281}
2282
2283void DwarfDebug::emitStringOffsetsTableHeader() {
2284 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2285 Holder.getStringPool().emitStringOffsetsTableHeader(
2286 *Asm, Asm->getObjFileLowering().getDwarfStrOffSection(),
2287 Holder.getStringOffsetsStartSym());
2288}
2289
2290template <typename AccelTableT>
2291void DwarfDebug::emitAccel(AccelTableT &Accel, MCSection *Section,
2292 StringRef TableName) {
2293 Asm->OutStreamer->SwitchSection(Section);
2294
2295 // Emit the full data.
2296 emitAppleAccelTable(Asm, Accel, TableName, Section->getBeginSymbol());
2297}
2298
2299void DwarfDebug::emitAccelDebugNames() {
2300 // Don't emit anything if we have no compilation units to index.
2301 if (getUnits().empty())
2302 return;
2303
2304 emitDWARF5AccelTable(Asm, AccelDebugNames, *this, getUnits());
2305}
2306
2307// Emit visible names into a hashed accelerator table section.
2308void DwarfDebug::emitAccelNames() {
2309 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
2310 "Names");
2311}
2312
2313// Emit objective C classes and categories into a hashed accelerator table
2314// section.
2315void DwarfDebug::emitAccelObjC() {
2316 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
2317 "ObjC");
2318}
2319
2320// Emit namespace dies into a hashed accelerator table.
2321void DwarfDebug::emitAccelNamespaces() {
2322 emitAccel(AccelNamespace,
2323 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
2324 "namespac");
2325}
2326
2327// Emit type dies into a hashed accelerator table.
2328void DwarfDebug::emitAccelTypes() {
2329 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
2330 "types");
2331}
2332
2333// Public name handling.
2334// The format for the various pubnames:
2335//
2336// dwarf pubnames - offset/name pairs where the offset is the offset into the CU
2337// for the DIE that is named.
2338//
2339// gnu pubnames - offset/index value/name tuples where the offset is the offset
2340// into the CU and the index value is computed according to the type of value
2341// for the DIE that is named.
2342//
2343// For type units the offset is the offset of the skeleton DIE. For split dwarf
2344// it's the offset within the debug_info/debug_types dwo section, however, the
2345// reference in the pubname header doesn't change.
2346
2347/// computeIndexValue - Compute the gdb index value for the DIE and CU.
2348static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
2349 const DIE *Die) {
2350 // Entities that ended up only in a Type Unit reference the CU instead (since
2351 // the pub entry has offsets within the CU there's no real offset that can be
2352 // provided anyway). As it happens all such entities (namespaces and types,
2353 // types only in C++ at that) are rendered as TYPE+EXTERNAL. If this turns out
2354 // not to be true it would be necessary to persist this information from the
2355 // point at which the entry is added to the index data structure - since by
2356 // the time the index is built from that, the original type/namespace DIE in a
2357 // type unit has already been destroyed so it can't be queried for properties
2358 // like tag, etc.
2359 if (Die->getTag() == dwarf::DW_TAG_compile_unit)
2360 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE,
2361 dwarf::GIEL_EXTERNAL);
2362 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
2363
2364 // We could have a specification DIE that has our most of our knowledge,
2365 // look for that now.
2366 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
2367 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
2368 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
2369 Linkage = dwarf::GIEL_EXTERNAL;
2370 } else if (Die->findAttribute(dwarf::DW_AT_external))
2371 Linkage = dwarf::GIEL_EXTERNAL;
2372
2373 switch (Die->getTag()) {
2374 case dwarf::DW_TAG_class_type:
2375 case dwarf::DW_TAG_structure_type:
2376 case dwarf::DW_TAG_union_type:
2377 case dwarf::DW_TAG_enumeration_type:
2378 return dwarf::PubIndexEntryDescriptor(
2379 dwarf::GIEK_TYPE,
2380 dwarf::isCPlusPlus((dwarf::SourceLanguage)CU->getLanguage())
2381 ? dwarf::GIEL_EXTERNAL
2382 : dwarf::GIEL_STATIC);
2383 case dwarf::DW_TAG_typedef:
2384 case dwarf::DW_TAG_base_type:
2385 case dwarf::DW_TAG_subrange_type:
2386 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
2387 case dwarf::DW_TAG_namespace:
2388 return dwarf::GIEK_TYPE;
2389 case dwarf::DW_TAG_subprogram:
2390 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
2391 case dwarf::DW_TAG_variable:
2392 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
2393 case dwarf::DW_TAG_enumerator:
2394 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
2395 dwarf::GIEL_STATIC);
2396 default:
2397 return dwarf::GIEK_NONE;
2398 }
2399}
2400
2401/// emitDebugPubSections - Emit visible names and types into debug pubnames and
2402/// pubtypes sections.
2403void DwarfDebug::emitDebugPubSections() {
2404 for (const auto &NU : CUMap) {
2405 DwarfCompileUnit *TheU = NU.second;
2406 if (!TheU->hasDwarfPubSections())
2407 continue;
2408
2409 bool GnuStyle = TheU->getCUNode()->getNameTableKind() ==
2410 DICompileUnit::DebugNameTableKind::GNU;
2411
2412 Asm->OutStreamer->SwitchSection(
2413 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2414 : Asm->getObjFileLowering().getDwarfPubNamesSection());
2415 emitDebugPubSection(GnuStyle, "Names", TheU, TheU->getGlobalNames());
2416
2417 Asm->OutStreamer->SwitchSection(
2418 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2419 : Asm->getObjFileLowering().getDwarfPubTypesSection());
2420 emitDebugPubSection(GnuStyle, "Types", TheU, TheU->getGlobalTypes());
2421 }
2422}
2423
2424void DwarfDebug::emitSectionReference(const DwarfCompileUnit &CU) {
2425 if (useSectionsAsReferences())
2426 Asm->emitDwarfOffset(CU.getSection()->getBeginSymbol(),
2427 CU.getDebugSectionOffset());
2428 else
2429 Asm->emitDwarfSymbolReference(CU.getLabelBegin());
2430}
2431
2432void DwarfDebug::emitDebugPubSection(bool GnuStyle, StringRef Name,
2433 DwarfCompileUnit *TheU,
2434 const StringMap<const DIE *> &Globals) {
2435 if (auto *Skeleton = TheU->getSkeleton())
2436 TheU = Skeleton;
2437
2438 // Emit the header.
2439 MCSymbol *EndLabel = Asm->emitDwarfUnitLength(
2440 "pub" + Name, "Length of Public " + Name + " Info");
2441
2442 Asm->OutStreamer->AddComment("DWARF Version");
2443 Asm->emitInt16(dwarf::DW_PUBNAMES_VERSION);
2444
2445 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
2446 emitSectionReference(*TheU);
2447
2448 Asm->OutStreamer->AddComment("Compilation Unit Length");
2449 Asm->emitDwarfLengthOrOffset(TheU->getLength());
2450
2451 // Emit the pubnames for this compilation unit.
2452 for (const auto &GI : Globals) {
2453 const char *Name = GI.getKeyData();
2454 const DIE *Entity = GI.second;
2455
2456 Asm->OutStreamer->AddComment("DIE offset");
2457 Asm->emitDwarfLengthOrOffset(Entity->getOffset());
2458
2459 if (GnuStyle) {
2460 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2461 Asm->OutStreamer->AddComment(
2462 Twine("Attributes: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) +
2463 ", " + dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2464 Asm->emitInt8(Desc.toBits());
2465 }
2466
2467 Asm->OutStreamer->AddComment("External Name");
2468 Asm->OutStreamer->emitBytes(StringRef(Name, GI.getKeyLength() + 1));
2469 }
2470
2471 Asm->OutStreamer->AddComment("End Mark");
2472 Asm->emitDwarfLengthOrOffset(0);
2473 Asm->OutStreamer->emitLabel(EndLabel);
2474}
2475
2476/// Emit null-terminated strings into a debug str section.
2477void DwarfDebug::emitDebugStr() {
2478 MCSection *StringOffsetsSection = nullptr;
2479 if (useSegmentedStringOffsetsTable()) {
2480 emitStringOffsetsTableHeader();
2481 StringOffsetsSection = Asm->getObjFileLowering().getDwarfStrOffSection();
2482 }
2483 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2484 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection(),
2485 StringOffsetsSection, /* UseRelativeOffsets = */ true);
2486}
2487
2488void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2489 const DebugLocStream::Entry &Entry,
2490 const DwarfCompileUnit *CU) {
2491 auto &&Comments = DebugLocs.getComments(Entry);
2492 auto Comment = Comments.begin();
2493 auto End = Comments.end();
2494
2495 // The expressions are inserted into a byte stream rather early (see
2496 // DwarfExpression::addExpression) so for those ops (e.g. DW_OP_convert) that
2497 // need to reference a base_type DIE the offset of that DIE is not yet known.
2498 // To deal with this we instead insert a placeholder early and then extract
2499 // it here and replace it with the real reference.
2500 unsigned PtrSize = Asm->MAI->getCodePointerSize();
2501 DWARFDataExtractor Data(StringRef(DebugLocs.getBytes(Entry).data(),
2502 DebugLocs.getBytes(Entry).size()),
2503 Asm->getDataLayout().isLittleEndian(), PtrSize);
2504 DWARFExpression Expr(Data, PtrSize, Asm->OutContext.getDwarfFormat());
2505
2506 using Encoding = DWARFExpression::Operation::Encoding;
2507 uint64_t Offset = 0;
2508 for (auto &Op : Expr) {
2509 assert(Op.getCode() != dwarf::DW_OP_const_type &&((void)0)
2510 "3 operand ops not yet supported")((void)0);
2511 Streamer.emitInt8(Op.getCode(), Comment != End ? *(Comment++) : "");
2512 Offset++;
2513 for (unsigned I = 0; I < 2; ++I) {
2514 if (Op.getDescription().Op[I] == Encoding::SizeNA)
2515 continue;
2516 if (Op.getDescription().Op[I] == Encoding::BaseTypeRef) {
2517 uint64_t Offset =
2518 CU->ExprRefedBaseTypes[Op.getRawOperand(I)].Die->getOffset();
2519 assert(Offset < (1ULL << (ULEB128PadSize * 7)) && "Offset wont fit")((void)0);
2520 Streamer.emitULEB128(Offset, "", ULEB128PadSize);
2521 // Make sure comments stay aligned.
2522 for (unsigned J = 0; J < ULEB128PadSize; ++J)
2523 if (Comment != End)
2524 Comment++;
2525 } else {
2526 for (uint64_t J = Offset; J < Op.getOperandEndOffset(I); ++J)
2527 Streamer.emitInt8(Data.getData()[J], Comment != End ? *(Comment++) : "");
2528 }
2529 Offset = Op.getOperandEndOffset(I);
2530 }
2531 assert(Offset == Op.getEndOffset())((void)0);
2532 }
2533}
2534
2535void DwarfDebug::emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
2536 const DbgValueLoc &Value,
2537 DwarfExpression &DwarfExpr) {
2538 auto *DIExpr = Value.getExpression();
2539 DIExpressionCursor ExprCursor(DIExpr);
2540 DwarfExpr.addFragmentOffset(DIExpr);
2541
2542 // If the DIExpr is is an Entry Value, we want to follow the same code path
2543 // regardless of whether the DBG_VALUE is variadic or not.
2544 if (DIExpr && DIExpr->isEntryValue()) {
2545 // Entry values can only be a single register with no additional DIExpr,
2546 // so just add it directly.
2547 assert(Value.getLocEntries().size() == 1)((void)0);
2548 assert(Value.getLocEntries()[0].isLocation())((void)0);
2549 MachineLocation Location = Value.getLocEntries()[0].getLoc();
2550 DwarfExpr.setLocation(Location, DIExpr);
2551
2552 DwarfExpr.beginEntryValueExpression(ExprCursor);
2553
2554 const TargetRegisterInfo &TRI = *AP.MF->getSubtarget().getRegisterInfo();
2555 if (!DwarfExpr.addMachineRegExpression(TRI, ExprCursor, Location.getReg()))
2556 return;
2557 return DwarfExpr.addExpression(std::move(ExprCursor));
2558 }
2559
2560 // Regular entry.
2561 auto EmitValueLocEntry = [&DwarfExpr, &BT,
2562 &AP](const DbgValueLocEntry &Entry,
2563 DIExpressionCursor &Cursor) -> bool {
2564 if (Entry.isInt()) {
2565 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
2566 BT->getEncoding() == dwarf::DW_ATE_signed_char))
2567 DwarfExpr.addSignedConstant(Entry.getInt());
2568 else
2569 DwarfExpr.addUnsignedConstant(Entry.getInt());
2570 } else if (Entry.isLocation()) {
2571 MachineLocation Location = Entry.getLoc();
2572 if (Location.isIndirect())
2573 DwarfExpr.setMemoryLocationKind();
2574
2575 const TargetRegisterInfo &TRI = *AP.MF->getSubtarget().getRegisterInfo();
2576 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
2577 return false;
2578 } else if (Entry.isTargetIndexLocation()) {
2579 TargetIndexLocation Loc = Entry.getTargetIndexLocation();
2580 // TODO TargetIndexLocation is a target-independent. Currently only the
2581 // WebAssembly-specific encoding is supported.
2582 assert(AP.TM.getTargetTriple().isWasm())((void)0);
2583 DwarfExpr.addWasmLocation(Loc.Index, static_cast<uint64_t>(Loc.Offset));
2584 } else if (Entry.isConstantFP()) {
2585 if (AP.getDwarfVersion() >= 4 && !AP.getDwarfDebug()->tuneForSCE() &&
2586 !Cursor) {
2587 DwarfExpr.addConstantFP(Entry.getConstantFP()->getValueAPF(), AP);
2588 } else if (Entry.getConstantFP()
2589 ->getValueAPF()
2590 .bitcastToAPInt()
2591 .getBitWidth() <= 64 /*bits*/) {
2592 DwarfExpr.addUnsignedConstant(
2593 Entry.getConstantFP()->getValueAPF().bitcastToAPInt());
2594 } else {
2595 LLVM_DEBUG(do { } while (false)
2596 dbgs() << "Skipped DwarfExpression creation for ConstantFP of size"do { } while (false)
2597 << Entry.getConstantFP()do { } while (false)
2598 ->getValueAPF()do { } while (false)
2599 .bitcastToAPInt()do { } while (false)
2600 .getBitWidth()do { } while (false)
2601 << " bits\n")do { } while (false);
2602 return false;
2603 }
2604 }
2605 return true;
2606 };
2607
2608 if (!Value.isVariadic()) {
2609 if (!EmitValueLocEntry(Value.getLocEntries()[0], ExprCursor))
2610 return;
2611 DwarfExpr.addExpression(std::move(ExprCursor));
2612 return;
2613 }
2614
2615 // If any of the location entries are registers with the value 0, then the
2616 // location is undefined.
2617 if (any_of(Value.getLocEntries(), [](const DbgValueLocEntry &Entry) {
2618 return Entry.isLocation() && !Entry.getLoc().getReg();
2619 }))
2620 return;
2621
2622 DwarfExpr.addExpression(
2623 std::move(ExprCursor),
2624 [EmitValueLocEntry, &Value](unsigned Idx,
2625 DIExpressionCursor &Cursor) -> bool {
2626 return EmitValueLocEntry(Value.getLocEntries()[Idx], Cursor);
2627 });
2628}
2629
2630void DebugLocEntry::finalize(const AsmPrinter &AP,
2631 DebugLocStream::ListBuilder &List,
2632 const DIBasicType *BT,
2633 DwarfCompileUnit &TheCU) {
2634 assert(!Values.empty() &&((void)0)
2635 "location list entries without values are redundant")((void)0);
2636 assert(Begin != End && "unexpected location list entry with empty range")((void)0);
2637 DebugLocStream::EntryBuilder Entry(List, Begin, End);
2638 BufferByteStreamer Streamer = Entry.getStreamer();
2639 DebugLocDwarfExpression DwarfExpr(AP.getDwarfVersion(), Streamer, TheCU);
2640 const DbgValueLoc &Value = Values[0];
2641 if (Value.isFragment()) {
2642 // Emit all fragments that belong to the same variable and range.
2643 assert(llvm::all_of(Values, [](DbgValueLoc P) {((void)0)
2644 return P.isFragment();((void)0)
2645 }) && "all values are expected to be fragments")((void)0);
2646 assert(llvm::is_sorted(Values) && "fragments are expected to be sorted")((void)0);
2647
2648 for (const auto &Fragment : Values)
2649 DwarfDebug::emitDebugLocValue(AP, BT, Fragment, DwarfExpr);
2650
2651 } else {
2652 assert(Values.size() == 1 && "only fragments may have >1 value")((void)0);
2653 DwarfDebug::emitDebugLocValue(AP, BT, Value, DwarfExpr);
2654 }
2655 DwarfExpr.finalize();
2656 if (DwarfExpr.TagOffset)
2657 List.setTagOffset(*DwarfExpr.TagOffset);
2658}
2659
2660void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry,
2661 const DwarfCompileUnit *CU) {
2662 // Emit the size.
2663 Asm->OutStreamer->AddComment("Loc expr size");
2664 if (getDwarfVersion() >= 5)
2665 Asm->emitULEB128(DebugLocs.getBytes(Entry).size());
2666 else if (DebugLocs.getBytes(Entry).size() <= std::numeric_limits<uint16_t>::max())
2667 Asm->emitInt16(DebugLocs.getBytes(Entry).size());
2668 else {
2669 // The entry is too big to fit into 16 bit, drop it as there is nothing we
2670 // can do.
2671 Asm->emitInt16(0);
2672 return;
2673 }
2674 // Emit the entry.
2675 APByteStreamer Streamer(*Asm);
2676 emitDebugLocEntry(Streamer, Entry, CU);
2677}
2678
2679// Emit the header of a DWARF 5 range list table list table. Returns the symbol
2680// that designates the end of the table for the caller to emit when the table is
2681// complete.
2682static MCSymbol *emitRnglistsTableHeader(AsmPrinter *Asm,
2683 const DwarfFile &Holder) {
2684 MCSymbol *TableEnd = mcdwarf::emitListsTableHeaderStart(*Asm->OutStreamer);
2685
2686 Asm->OutStreamer->AddComment("Offset entry count");
2687 Asm->emitInt32(Holder.getRangeLists().size());
2688 Asm->OutStreamer->emitLabel(Holder.getRnglistsTableBaseSym());
2689
2690 for (const RangeSpanList &List : Holder.getRangeLists())
2691 Asm->emitLabelDifference(List.Label, Holder.getRnglistsTableBaseSym(),
2692 Asm->getDwarfOffsetByteSize());
2693
2694 return TableEnd;
2695}
2696
2697// Emit the header of a DWARF 5 locations list table. Returns the symbol that
2698// designates the end of the table for the caller to emit when the table is
2699// complete.
2700static MCSymbol *emitLoclistsTableHeader(AsmPrinter *Asm,
2701 const DwarfDebug &DD) {
2702 MCSymbol *TableEnd = mcdwarf::emitListsTableHeaderStart(*Asm->OutStreamer);
2703
2704 const auto &DebugLocs = DD.getDebugLocs();
2705
2706 Asm->OutStreamer->AddComment("Offset entry count");
2707 Asm->emitInt32(DebugLocs.getLists().size());
2708 Asm->OutStreamer->emitLabel(DebugLocs.getSym());
2709
2710 for (const auto &List : DebugLocs.getLists())
2711 Asm->emitLabelDifference(List.Label, DebugLocs.getSym(),
2712 Asm->getDwarfOffsetByteSize());
2713
2714 return TableEnd;
2715}
2716
2717template <typename Ranges, typename PayloadEmitter>
2718static void emitRangeList(
2719 DwarfDebug &DD, AsmPrinter *Asm, MCSymbol *Sym, const Ranges &R,
2720 const DwarfCompileUnit &CU, unsigned BaseAddressx, unsigned OffsetPair,
2721 unsigned StartxLength, unsigned EndOfList,
2722 StringRef (*StringifyEnum)(unsigned),
2723 bool ShouldUseBaseAddress,
2724 PayloadEmitter EmitPayload) {
2725
2726 auto Size = Asm->MAI->getCodePointerSize();
2727 bool UseDwarf5 = DD.getDwarfVersion() >= 5;
2728
2729 // Emit our symbol so we can find the beginning of the range.
2730 Asm->OutStreamer->emitLabel(Sym);
2731
2732 // Gather all the ranges that apply to the same section so they can share
2733 // a base address entry.
2734 MapVector<const MCSection *, std::vector<decltype(&*R.begin())>> SectionRanges;
2735
2736 for (const auto &Range : R)
2737 SectionRanges[&Range.Begin->getSection()].push_back(&Range);
2738
2739 const MCSymbol *CUBase = CU.getBaseAddress();
2740 bool BaseIsSet = false;
2741 for (const auto &P : SectionRanges) {
2742 auto *Base = CUBase;
2743 if (!Base && ShouldUseBaseAddress) {
2744 const MCSymbol *Begin = P.second.front()->Begin;
2745 const MCSymbol *NewBase = DD.getSectionLabel(&Begin->getSection());
2746 if (!UseDwarf5) {
2747 Base = NewBase;
2748 BaseIsSet = true;
2749 Asm->OutStreamer->emitIntValue(-1, Size);
2750 Asm->OutStreamer->AddComment(" base address");
2751 Asm->OutStreamer->emitSymbolValue(Base, Size);
2752 } else if (NewBase != Begin || P.second.size() > 1) {
2753 // Only use a base address if
2754 // * the existing pool address doesn't match (NewBase != Begin)
2755 // * or, there's more than one entry to share the base address
2756 Base = NewBase;
2757 BaseIsSet = true;
2758 Asm->OutStreamer->AddComment(StringifyEnum(BaseAddressx));
2759 Asm->emitInt8(BaseAddressx);
2760 Asm->OutStreamer->AddComment(" base address index");
2761 Asm->emitULEB128(DD.getAddressPool().getIndex(Base));
2762 }
2763 } else if (BaseIsSet && !UseDwarf5) {
2764 BaseIsSet = false;
2765 assert(!Base)((void)0);
2766 Asm->OutStreamer->emitIntValue(-1, Size);
2767 Asm->OutStreamer->emitIntValue(0, Size);
2768 }
2769
2770 for (const auto *RS : P.second) {
2771 const MCSymbol *Begin = RS->Begin;
2772 const MCSymbol *End = RS->End;
2773 assert(Begin && "Range without a begin symbol?")((void)0);
2774 assert(End && "Range without an end symbol?")((void)0);
2775 if (Base) {
2776 if (UseDwarf5) {
2777 // Emit offset_pair when we have a base.
2778 Asm->OutStreamer->AddComment(StringifyEnum(OffsetPair));
2779 Asm->emitInt8(OffsetPair);
2780 Asm->OutStreamer->AddComment(" starting offset");
2781 Asm->emitLabelDifferenceAsULEB128(Begin, Base);
2782 Asm->OutStreamer->AddComment(" ending offset");
2783 Asm->emitLabelDifferenceAsULEB128(End, Base);
2784 } else {
2785 Asm->emitLabelDifference(Begin, Base, Size);
2786 Asm->emitLabelDifference(End, Base, Size);
2787 }
2788 } else if (UseDwarf5) {
2789 Asm->OutStreamer->AddComment(StringifyEnum(StartxLength));
2790 Asm->emitInt8(StartxLength);
2791 Asm->OutStreamer->AddComment(" start index");
2792 Asm->emitULEB128(DD.getAddressPool().getIndex(Begin));
2793 Asm->OutStreamer->AddComment(" length");
2794 Asm->emitLabelDifferenceAsULEB128(End, Begin);
2795 } else {
2796 Asm->OutStreamer->emitSymbolValue(Begin, Size);
2797 Asm->OutStreamer->emitSymbolValue(End, Size);
2798 }
2799 EmitPayload(*RS);
2800 }
2801 }
2802
2803 if (UseDwarf5) {
2804 Asm->OutStreamer->AddComment(StringifyEnum(EndOfList));
2805 Asm->emitInt8(EndOfList);
2806 } else {
2807 // Terminate the list with two 0 values.
2808 Asm->OutStreamer->emitIntValue(0, Size);
2809 Asm->OutStreamer->emitIntValue(0, Size);
2810 }
2811}
2812
2813// Handles emission of both debug_loclist / debug_loclist.dwo
2814static void emitLocList(DwarfDebug &DD, AsmPrinter *Asm, const DebugLocStream::List &List) {
2815 emitRangeList(DD, Asm, List.Label, DD.getDebugLocs().getEntries(List),
2816 *List.CU, dwarf::DW_LLE_base_addressx,
2817 dwarf::DW_LLE_offset_pair, dwarf::DW_LLE_startx_length,
2818 dwarf::DW_LLE_end_of_list, llvm::dwarf::LocListEncodingString,
2819 /* ShouldUseBaseAddress */ true,
2820 [&](const DebugLocStream::Entry &E) {
2821 DD.emitDebugLocEntryLocation(E, List.CU);
2822 });
2823}
2824
2825void DwarfDebug::emitDebugLocImpl(MCSection *Sec) {
2826 if (DebugLocs.getLists().empty())
2827 return;
2828
2829 Asm->OutStreamer->SwitchSection(Sec);
2830
2831 MCSymbol *TableEnd = nullptr;
2832 if (getDwarfVersion() >= 5)
2833 TableEnd = emitLoclistsTableHeader(Asm, *this);
2834
2835 for (const auto &List : DebugLocs.getLists())
2836 emitLocList(*this, Asm, List);
2837
2838 if (TableEnd)
2839 Asm->OutStreamer->emitLabel(TableEnd);
2840}
2841
2842// Emit locations into the .debug_loc/.debug_loclists section.
2843void DwarfDebug::emitDebugLoc() {
2844 emitDebugLocImpl(
2845 getDwarfVersion() >= 5
2846 ? Asm->getObjFileLowering().getDwarfLoclistsSection()
2847 : Asm->getObjFileLowering().getDwarfLocSection());
2848}
2849
2850// Emit locations into the .debug_loc.dwo/.debug_loclists.dwo section.
2851void DwarfDebug::emitDebugLocDWO() {
2852 if (getDwarfVersion() >= 5) {
2853 emitDebugLocImpl(
2854 Asm->getObjFileLowering().getDwarfLoclistsDWOSection());
2855
2856 return;
2857 }
2858
2859 for (const auto &List : DebugLocs.getLists()) {
2860 Asm->OutStreamer->SwitchSection(
2861 Asm->getObjFileLowering().getDwarfLocDWOSection());
2862 Asm->OutStreamer->emitLabel(List.Label);
2863
2864 for (const auto &Entry : DebugLocs.getEntries(List)) {
2865 // GDB only supports startx_length in pre-standard split-DWARF.
2866 // (in v5 standard loclists, it currently* /only/ supports base_address +
2867 // offset_pair, so the implementations can't really share much since they
2868 // need to use different representations)
2869 // * as of October 2018, at least
2870 //
2871 // In v5 (see emitLocList), this uses SectionLabels to reuse existing
2872 // addresses in the address pool to minimize object size/relocations.
2873 Asm->emitInt8(dwarf::DW_LLE_startx_length);
2874 unsigned idx = AddrPool.getIndex(Entry.Begin);
2875 Asm->emitULEB128(idx);
2876 // Also the pre-standard encoding is slightly different, emitting this as
2877 // an address-length entry here, but its a ULEB128 in DWARFv5 loclists.
2878 Asm->emitLabelDifference(Entry.End, Entry.Begin, 4);
2879 emitDebugLocEntryLocation(Entry, List.CU);
2880 }
2881 Asm->emitInt8(dwarf::DW_LLE_end_of_list);
2882 }
2883}
2884
2885struct ArangeSpan {
2886 const MCSymbol *Start, *End;
2887};
2888
2889// Emit a debug aranges section, containing a CU lookup for any
2890// address we can tie back to a CU.
2891void DwarfDebug::emitDebugARanges() {
2892 // Provides a unique id per text section.
2893 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
2894
2895 // Filter labels by section.
2896 for (const SymbolCU &SCU : ArangeLabels) {
2897 if (SCU.Sym->isInSection()) {
2898 // Make a note of this symbol and it's section.
2899 MCSection *Section = &SCU.Sym->getSection();
2900 if (!Section->getKind().isMetadata())
2901 SectionMap[Section].push_back(SCU);
2902 } else {
2903 // Some symbols (e.g. common/bss on mach-o) can have no section but still
2904 // appear in the output. This sucks as we rely on sections to build
2905 // arange spans. We can do it without, but it's icky.
2906 SectionMap[nullptr].push_back(SCU);
2907 }
2908 }
2909
2910 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
2911
2912 for (auto &I : SectionMap) {
2913 MCSection *Section = I.first;
2914 SmallVector<SymbolCU, 8> &List = I.second;
2915 if (List.size() < 1)
2916 continue;
2917
2918 // If we have no section (e.g. common), just write out
2919 // individual spans for each symbol.
2920 if (!Section) {
2921 for (const SymbolCU &Cur : List) {
2922 ArangeSpan Span;
2923 Span.Start = Cur.Sym;
2924 Span.End = nullptr;
2925 assert(Cur.CU)((void)0);
2926 Spans[Cur.CU].push_back(Span);
2927 }
2928 continue;
2929 }
2930
2931 // Sort the symbols by offset within the section.
2932 llvm::stable_sort(List, [&](const SymbolCU &A, const SymbolCU &B) {
2933 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
2934 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
2935
2936 // Symbols with no order assigned should be placed at the end.
2937 // (e.g. section end labels)
2938 if (IA == 0)
2939 return false;
2940 if (IB == 0)
2941 return true;
2942 return IA < IB;
2943 });
2944
2945 // Insert a final terminator.
2946 List.push_back(SymbolCU(nullptr, Asm->OutStreamer->endSection(Section)));
2947
2948 // Build spans between each label.
2949 const MCSymbol *StartSym = List[0].Sym;
2950 for (size_t n = 1, e = List.size(); n < e; n++) {
2951 const SymbolCU &Prev = List[n - 1];
2952 const SymbolCU &Cur = List[n];
2953
2954 // Try and build the longest span we can within the same CU.
2955 if (Cur.CU != Prev.CU) {
2956 ArangeSpan Span;
2957 Span.Start = StartSym;
2958 Span.End = Cur.Sym;
2959 assert(Prev.CU)((void)0);
2960 Spans[Prev.CU].push_back(Span);
2961 StartSym = Cur.Sym;
2962 }
2963 }
2964 }
2965
2966 // Start the dwarf aranges section.
2967 Asm->OutStreamer->SwitchSection(
2968 Asm->getObjFileLowering().getDwarfARangesSection());
2969
2970 unsigned PtrSize = Asm->MAI->getCodePointerSize();
2971
2972 // Build a list of CUs used.
2973 std::vector<DwarfCompileUnit *> CUs;
2974 for (const auto &it : Spans) {
2975 DwarfCompileUnit *CU = it.first;
2976 CUs.push_back(CU);
2977 }
2978
2979 // Sort the CU list (again, to ensure consistent output order).
2980 llvm::sort(CUs, [](const DwarfCompileUnit *A, const DwarfCompileUnit *B) {
2981 return A->getUniqueID() < B->getUniqueID();
2982 });
2983
2984 // Emit an arange table for each CU we used.
2985 for (DwarfCompileUnit *CU : CUs) {
2986 std::vector<ArangeSpan> &List = Spans[CU];
2987
2988 // Describe the skeleton CU's offset and length, not the dwo file's.
2989 if (auto *Skel = CU->getSkeleton())
2990 CU = Skel;
2991
2992 // Emit size of content not including length itself.
2993 unsigned ContentSize =
2994 sizeof(int16_t) + // DWARF ARange version number
2995 Asm->getDwarfOffsetByteSize() + // Offset of CU in the .debug_info
2996 // section
2997 sizeof(int8_t) + // Pointer Size (in bytes)
2998 sizeof(int8_t); // Segment Size (in bytes)
2999
3000 unsigned TupleSize = PtrSize * 2;
3001
3002 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
3003 unsigned Padding = offsetToAlignment(
3004 Asm->getUnitLengthFieldByteSize() + ContentSize, Align(TupleSize));
3005
3006 ContentSize += Padding;
3007 ContentSize += (List.size() + 1) * TupleSize;
3008
3009 // For each compile unit, write the list of spans it covers.
3010 Asm->emitDwarfUnitLength(ContentSize, "Length of ARange Set");
3011 Asm->OutStreamer->AddComment("DWARF Arange version number");
3012 Asm->emitInt16(dwarf::DW_ARANGES_VERSION);
3013 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
3014 emitSectionReference(*CU);
3015 Asm->OutStreamer->AddComment("Address Size (in bytes)");
3016 Asm->emitInt8(PtrSize);
3017 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
3018 Asm->emitInt8(0);
3019
3020 Asm->OutStreamer->emitFill(Padding, 0xff);
3021
3022 for (const ArangeSpan &Span : List) {
3023 Asm->emitLabelReference(Span.Start, PtrSize);
3024
3025 // Calculate the size as being from the span start to it's end.
3026 if (Span.End) {
3027 Asm->emitLabelDifference(Span.End, Span.Start, PtrSize);
3028 } else {
3029 // For symbols without an end marker (e.g. common), we
3030 // write a single arange entry containing just that one symbol.
3031 uint64_t Size = SymSize[Span.Start];
3032 if (Size == 0)
3033 Size = 1;
3034
3035 Asm->OutStreamer->emitIntValue(Size, PtrSize);
3036 }
3037 }
3038
3039 Asm->OutStreamer->AddComment("ARange terminator");
3040 Asm->OutStreamer->emitIntValue(0, PtrSize);
3041 Asm->OutStreamer->emitIntValue(0, PtrSize);
3042 }
3043}
3044
3045/// Emit a single range list. We handle both DWARF v5 and earlier.
3046static void emitRangeList(DwarfDebug &DD, AsmPrinter *Asm,
3047 const RangeSpanList &List) {
3048 emitRangeList(DD, Asm, List.Label, List.Ranges, *List.CU,
3049 dwarf::DW_RLE_base_addressx, dwarf::DW_RLE_offset_pair,
3050 dwarf::DW_RLE_startx_length, dwarf::DW_RLE_end_of_list,
3051 llvm::dwarf::RangeListEncodingString,
3052 List.CU->getCUNode()->getRangesBaseAddress() ||
3053 DD.getDwarfVersion() >= 5,
3054 [](auto) {});
3055}
3056
3057void DwarfDebug::emitDebugRangesImpl(const DwarfFile &Holder, MCSection *Section) {
3058 if (Holder.getRangeLists().empty())
3059 return;
3060
3061 assert(useRangesSection())((void)0);
3062 assert(!CUMap.empty())((void)0);
3063 assert(llvm::any_of(CUMap, [](const decltype(CUMap)::value_type &Pair) {((void)0)
3064 return !Pair.second->getCUNode()->isDebugDirectivesOnly();((void)0)
3065 }))((void)0);
3066
3067 Asm->OutStreamer->SwitchSection(Section);
3068
3069 MCSymbol *TableEnd = nullptr;
3070 if (getDwarfVersion() >= 5)
3071 TableEnd = emitRnglistsTableHeader(Asm, Holder);
3072
3073 for (const RangeSpanList &List : Holder.getRangeLists())
3074 emitRangeList(*this, Asm, List);
3075
3076 if (TableEnd)
3077 Asm->OutStreamer->emitLabel(TableEnd);
3078}
3079
3080/// Emit address ranges into the .debug_ranges section or into the DWARF v5
3081/// .debug_rnglists section.
3082void DwarfDebug::emitDebugRanges() {
3083 const auto &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
3084
3085 emitDebugRangesImpl(Holder,
3086 getDwarfVersion() >= 5
3087 ? Asm->getObjFileLowering().getDwarfRnglistsSection()
3088 : Asm->getObjFileLowering().getDwarfRangesSection());
3089}
3090
3091void DwarfDebug::emitDebugRangesDWO() {
3092 emitDebugRangesImpl(InfoHolder,
3093 Asm->getObjFileLowering().getDwarfRnglistsDWOSection());
3094}
3095
3096/// Emit the header of a DWARF 5 macro section, or the GNU extension for
3097/// DWARF 4.
3098static void emitMacroHeader(AsmPrinter *Asm, const DwarfDebug &DD,
3099 const DwarfCompileUnit &CU, uint16_t DwarfVersion) {
3100 enum HeaderFlagMask {
3101#define HANDLE_MACRO_FLAG(ID, NAME) MACRO_FLAG_##NAME = ID,
3102#include "llvm/BinaryFormat/Dwarf.def"
3103 };
3104 Asm->OutStreamer->AddComment("Macro information version");
3105 Asm->emitInt16(DwarfVersion >= 5 ? DwarfVersion : 4);
3106 // We emit the line offset flag unconditionally here, since line offset should
3107 // be mostly present.
3108 if (Asm->isDwarf64()) {
3109 Asm->OutStreamer->AddComment("Flags: 64 bit, debug_line_offset present");
3110 Asm->emitInt8(MACRO_FLAG_OFFSET_SIZE | MACRO_FLAG_DEBUG_LINE_OFFSET);
3111 } else {
3112 Asm->OutStreamer->AddComment("Flags: 32 bit, debug_line_offset present");
3113 Asm->emitInt8(MACRO_FLAG_DEBUG_LINE_OFFSET);
3114 }
3115 Asm->OutStreamer->AddComment("debug_line_offset");
3116 if (DD.useSplitDwarf())
3117 Asm->emitDwarfLengthOrOffset(0);
3118 else
3119 Asm->emitDwarfSymbolReference(CU.getLineTableStartSym());
3120}
3121
3122void DwarfDebug::handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U) {
3123 for (auto *MN : Nodes) {
3124 if (auto *M = dyn_cast<DIMacro>(MN))
3125 emitMacro(*M);
3126 else if (auto *F = dyn_cast<DIMacroFile>(MN))
3127 emitMacroFile(*F, U);
3128 else
3129 llvm_unreachable("Unexpected DI type!")__builtin_unreachable();
3130 }
3131}
3132
3133void DwarfDebug::emitMacro(DIMacro &M) {
3134 StringRef Name = M.getName();
3135 StringRef Value = M.getValue();
3136
3137 // There should be one space between the macro name and the macro value in
3138 // define entries. In undef entries, only the macro name is emitted.
3139 std::string Str = Value.empty() ? Name.str() : (Name + " " + Value).str();
3140
3141 if (UseDebugMacroSection) {
3142 if (getDwarfVersion() >= 5) {
3143 unsigned Type = M.getMacinfoType() == dwarf::DW_MACINFO_define
3144 ? dwarf::DW_MACRO_define_strx
3145 : dwarf::DW_MACRO_undef_strx;
3146 Asm->OutStreamer->AddComment(dwarf::MacroString(Type));
3147 Asm->emitULEB128(Type);
3148 Asm->OutStreamer->AddComment("Line Number");
3149 Asm->emitULEB128(M.getLine());
3150 Asm->OutStreamer->AddComment("Macro String");
3151 Asm->emitULEB128(
3152 InfoHolder.getStringPool().getIndexedEntry(*Asm, Str).getIndex());
3153 } else {
3154 unsigned Type = M.getMacinfoType() == dwarf::DW_MACINFO_define
3155 ? dwarf::DW_MACRO_GNU_define_indirect
3156 : dwarf::DW_MACRO_GNU_undef_indirect;
3157 Asm->OutStreamer->AddComment(dwarf::GnuMacroString(Type));
3158 Asm->emitULEB128(Type);
3159 Asm->OutStreamer->AddComment("Line Number");
3160 Asm->emitULEB128(M.getLine());
3161 Asm->OutStreamer->AddComment("Macro String");
3162 Asm->emitDwarfSymbolReference(
3163 InfoHolder.getStringPool().getEntry(*Asm, Str).getSymbol());
3164 }
3165 } else {
3166 Asm->OutStreamer->AddComment(dwarf::MacinfoString(M.getMacinfoType()));
3167 Asm->emitULEB128(M.getMacinfoType());
3168 Asm->OutStreamer->AddComment("Line Number");
3169 Asm->emitULEB128(M.getLine());
3170 Asm->OutStreamer->AddComment("Macro String");
3171 Asm->OutStreamer->emitBytes(Str);
3172 Asm->emitInt8('\0');
3173 }
3174}
3175
3176void DwarfDebug::emitMacroFileImpl(
3177 DIMacroFile &MF, DwarfCompileUnit &U, unsigned StartFile, unsigned EndFile,
3178 StringRef (*MacroFormToString)(unsigned Form)) {
3179
3180 Asm->OutStreamer->AddComment(MacroFormToString(StartFile));
3181 Asm->emitULEB128(StartFile);
3182 Asm->OutStreamer->AddComment("Line Number");
3183 Asm->emitULEB128(MF.getLine());
3184 Asm->OutStreamer->AddComment("File Number");
3185 DIFile &F = *MF.getFile();
3186 if (useSplitDwarf())
3187 Asm->emitULEB128(getDwoLineTable(U)->getFile(
3188 F.getDirectory(), F.getFilename(), getMD5AsBytes(&F),
3189 Asm->OutContext.getDwarfVersion(), F.getSource()));
3190 else
3191 Asm->emitULEB128(U.getOrCreateSourceID(&F));
3192 handleMacroNodes(MF.getElements(), U);
3193 Asm->OutStreamer->AddComment(MacroFormToString(EndFile));
3194 Asm->emitULEB128(EndFile);
3195}
3196
3197void DwarfDebug::emitMacroFile(DIMacroFile &F, DwarfCompileUnit &U) {
3198 // DWARFv5 macro and DWARFv4 macinfo share some common encodings,
3199 // so for readibility/uniformity, We are explicitly emitting those.
3200 assert(F.getMacinfoType() == dwarf::DW_MACINFO_start_file)((void)0);
3201 if (UseDebugMacroSection)
3202 emitMacroFileImpl(
3203 F, U, dwarf::DW_MACRO_start_file, dwarf::DW_MACRO_end_file,
3204 (getDwarfVersion() >= 5) ? dwarf::MacroString : dwarf::GnuMacroString);
3205 else
3206 emitMacroFileImpl(F, U, dwarf::DW_MACINFO_start_file,
3207 dwarf::DW_MACINFO_end_file, dwarf::MacinfoString);
3208}
3209
3210void DwarfDebug::emitDebugMacinfoImpl(MCSection *Section) {
3211 for (const auto &P : CUMap) {
3212 auto &TheCU = *P.second;
3213 auto *SkCU = TheCU.getSkeleton();
3214 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
3215 auto *CUNode = cast<DICompileUnit>(P.first);
3216 DIMacroNodeArray Macros = CUNode->getMacros();
3217 if (Macros.empty())
3218 continue;
3219 Asm->OutStreamer->SwitchSection(Section);
3220 Asm->OutStreamer->emitLabel(U.getMacroLabelBegin());
3221 if (UseDebugMacroSection)
3222 emitMacroHeader(Asm, *this, U, getDwarfVersion());
3223 handleMacroNodes(Macros, U);
3224 Asm->OutStreamer->AddComment("End Of Macro List Mark");
3225 Asm->emitInt8(0);
3226 }
3227}
3228
3229/// Emit macros into a debug macinfo/macro section.
3230void DwarfDebug::emitDebugMacinfo() {
3231 auto &ObjLower = Asm->getObjFileLowering();
3232 emitDebugMacinfoImpl(UseDebugMacroSection
3233 ? ObjLower.getDwarfMacroSection()
3234 : ObjLower.getDwarfMacinfoSection());
3235}
3236
3237void DwarfDebug::emitDebugMacinfoDWO() {
3238 auto &ObjLower = Asm->getObjFileLowering();
3239 emitDebugMacinfoImpl(UseDebugMacroSection
3240 ? ObjLower.getDwarfMacroDWOSection()
3241 : ObjLower.getDwarfMacinfoDWOSection());
3242}
3243
3244// DWARF5 Experimental Separate Dwarf emitters.
3245
3246void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
3247 std::unique_ptr<DwarfCompileUnit> NewU) {
3248
3249 if (!CompilationDir.empty())
3250 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
3251 addGnuPubAttributes(*NewU, Die);
3252
3253 SkeletonHolder.addUnit(std::move(NewU));
3254}
3255
3256DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
3257
3258 auto OwnedUnit = std::make_unique<DwarfCompileUnit>(
3259 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder,
3260 UnitKind::Skeleton);
3261 DwarfCompileUnit &NewCU = *OwnedUnit;
3262 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());
3263
3264 NewCU.initStmtList();
3265
3266 if (useSegmentedStringOffsetsTable())
3267 NewCU.addStringOffsetsStart();
3268
3269 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
3270
3271 return NewCU;
3272}
3273
3274// Emit the .debug_info.dwo section for separated dwarf. This contains the
3275// compile units that would normally be in debug_info.
3276void DwarfDebug::emitDebugInfoDWO() {
3277 assert(useSplitDwarf() && "No split dwarf debug info?")((void)0);
3278 // Don't emit relocations into the dwo file.
3279 InfoHolder.emitUnits(/* UseOffsets */ true);
3280}
3281
3282// Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
3283// abbreviations for the .debug_info.dwo section.
3284void DwarfDebug::emitDebugAbbrevDWO() {
3285 assert(useSplitDwarf() && "No split dwarf?")((void)0);
3286 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
3287}
3288
3289void DwarfDebug::emitDebugLineDWO() {
3290 assert(useSplitDwarf() && "No split dwarf?")((void)0);
3291 SplitTypeUnitFileTable.Emit(
3292 *Asm->OutStreamer, MCDwarfLineTableParams(),
3293 Asm->getObjFileLowering().getDwarfLineDWOSection());
3294}
3295
3296void DwarfDebug::emitStringOffsetsTableHeaderDWO() {
3297 assert(useSplitDwarf() && "No split dwarf?")((void)0);
3298 InfoHolder.getStringPool().emitStringOffsetsTableHeader(
3299 *Asm, Asm->getObjFileLowering().getDwarfStrOffDWOSection(),
3300 InfoHolder.getStringOffsetsStartSym());
3301}
3302
3303// Emit the .debug_str.dwo section for separated dwarf. This contains the
3304// string section and is identical in format to traditional .debug_str
3305// sections.
3306void DwarfDebug::emitDebugStrDWO() {
3307 if (useSegmentedStringOffsetsTable())
3308 emitStringOffsetsTableHeaderDWO();
3309 assert(useSplitDwarf() && "No split dwarf?")((void)0);
3310 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
3311 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
3312 OffSec, /* UseRelativeOffsets = */ false);
3313}
3314
3315// Emit address pool.
3316void DwarfDebug::emitDebugAddr() {
3317 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
3318}
3319
3320MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
3321 if (!useSplitDwarf())
3322 return nullptr;
3323 const DICompileUnit *DIUnit = CU.getCUNode();
3324 SplitTypeUnitFileTable.maybeSetRootFile(
3325 DIUnit->getDirectory(), DIUnit->getFilename(),
3326 getMD5AsBytes(DIUnit->getFile()), DIUnit->getSource());
3327 return &SplitTypeUnitFileTable;
3328}
3329
3330uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
3331 MD5 Hash;
3332 Hash.update(Identifier);
3333 // ... take the least significant 8 bytes and return those. Our MD5
3334 // implementation always returns its results in little endian, so we actually
3335 // need the "high" word.
3336 MD5::MD5Result Result;
3337 Hash.final(Result);
3338 return Result.high();
3339}
3340
3341void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
3342 StringRef Identifier, DIE &RefDie,
3343 const DICompositeType *CTy) {
3344 // Fast path if we're building some type units and one has already used the
3345 // address pool we know we're going to throw away all this work anyway, so
3346 // don't bother building dependent types.
3347 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
3348 return;
3349
3350 auto Ins = TypeSignatures.insert(std::make_pair(CTy, 0));
3351 if (!Ins.second) {
3352 CU.addDIETypeSignature(RefDie, Ins.first->second);
3353 return;
3354 }
3355
3356 bool TopLevelType = TypeUnitsUnderConstruction.empty();
3357 AddrPool.resetUsedFlag();
3358
3359 auto OwnedUnit = std::make_unique<DwarfTypeUnit>(CU, Asm, this, &InfoHolder,
3360 getDwoLineTable(CU));
3361 DwarfTypeUnit &NewTU = *OwnedUnit;
3362 DIE &UnitDie = NewTU.getUnitDie();
3363 TypeUnitsUnderConstruction.emplace_back(std::move(OwnedUnit), CTy);
3364
3365 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
3366 CU.getLanguage());
3367
3368 uint64_t Signature = makeTypeSignature(Identifier);
3369 NewTU.setTypeSignature(Signature);
3370 Ins.first->second = Signature;
3371
3372 if (useSplitDwarf()) {
3373 MCSection *Section =
3374 getDwarfVersion() <= 4
3375 ? Asm->getObjFileLowering().getDwarfTypesDWOSection()
3376 : Asm->getObjFileLowering().getDwarfInfoDWOSection();
3377 NewTU.setSection(Section);
3378 } else {
3379 MCSection *Section =
3380 getDwarfVersion() <= 4
3381 ? Asm->getObjFileLowering().getDwarfTypesSection(Signature)
3382 : Asm->getObjFileLowering().getDwarfInfoSection(Signature);
3383 NewTU.setSection(Section);
3384 // Non-split type units reuse the compile unit's line table.
3385 CU.applyStmtList(UnitDie);
3386 }
3387
3388 // Add DW_AT_str_offsets_base to the type unit DIE, but not for split type
3389 // units.
3390 if (useSegmentedStringOffsetsTable() && !useSplitDwarf())
3391 NewTU.addStringOffsetsStart();
3392
3393 NewTU.setType(NewTU.createTypeDIE(CTy));
3394
3395 if (TopLevelType) {
3396 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
3397 TypeUnitsUnderConstruction.clear();
3398
3399 // Types referencing entries in the address table cannot be placed in type
3400 // units.
3401 if (AddrPool.hasBeenUsed()) {
3402
3403 // Remove all the types built while building this type.
3404 // This is pessimistic as some of these types might not be dependent on
3405 // the type that used an address.
3406 for (const auto &TU : TypeUnitsToAdd)
3407 TypeSignatures.erase(TU.second);
3408
3409 // Construct this type in the CU directly.
3410 // This is inefficient because all the dependent types will be rebuilt
3411 // from scratch, including building them in type units, discovering that
3412 // they depend on addresses, throwing them out and rebuilding them.
3413 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
3414 return;
3415 }
3416
3417 // If the type wasn't dependent on fission addresses, finish adding the type
3418 // and all its dependent types.
3419 for (auto &TU : TypeUnitsToAdd) {
3420 InfoHolder.computeSizeAndOffsetsForUnit(TU.first.get());
3421 InfoHolder.emitUnit(TU.first.get(), useSplitDwarf());
3422 }
3423 }
3424 CU.addDIETypeSignature(RefDie, Signature);
3425}
3426
3427DwarfDebug::NonTypeUnitContext::NonTypeUnitContext(DwarfDebug *DD)
3428 : DD(DD),
3429 TypeUnitsUnderConstruction(std::move(DD->TypeUnitsUnderConstruction)), AddrPoolUsed(DD->AddrPool.hasBeenUsed()) {
3430 DD->TypeUnitsUnderConstruction.clear();
3431 DD->AddrPool.resetUsedFlag();
3432}
3433
3434DwarfDebug::NonTypeUnitContext::~NonTypeUnitContext() {
3435 DD->TypeUnitsUnderConstruction = std::move(TypeUnitsUnderConstruction);
3436 DD->AddrPool.resetUsedFlag(AddrPoolUsed);
3437}
3438
3439DwarfDebug::NonTypeUnitContext DwarfDebug::enterNonTypeUnitContext() {
3440 return NonTypeUnitContext(this);
3441}
3442
3443// Add the Name along with its companion DIE to the appropriate accelerator
3444// table (for AccelTableKind::Dwarf it's always AccelDebugNames, for
3445// AccelTableKind::Apple, we use the table we got as an argument). If
3446// accelerator tables are disabled, this function does nothing.
3447template <typename DataT>
3448void DwarfDebug::addAccelNameImpl(const DICompileUnit &CU,
3449 AccelTable<DataT> &AppleAccel, StringRef Name,
3450 const DIE &Die) {
3451 if (getAccelTableKind() == AccelTableKind::None)
3452 return;
3453
3454 if (getAccelTableKind() != AccelTableKind::Apple &&
3455 CU.getNameTableKind() != DICompileUnit::DebugNameTableKind::Default)
3456 return;
3457
3458 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
3459 DwarfStringPoolEntryRef Ref = Holder.getStringPool().getEntry(*Asm, Name);
3460
3461 switch (getAccelTableKind()) {
3462 case AccelTableKind::Apple:
3463 AppleAccel.addName(Ref, Die);
3464 break;
3465 case AccelTableKind::Dwarf:
3466 AccelDebugNames.addName(Ref, Die);
3467 break;
3468 case AccelTableKind::Default:
3469 llvm_unreachable("Default should have already been resolved.")__builtin_unreachable();
3470 case AccelTableKind::None:
3471 llvm_unreachable("None handled above")__builtin_unreachable();
3472 }
3473}
3474
3475void DwarfDebug::addAccelName(const DICompileUnit &CU, StringRef Name,
3476 const DIE &Die) {
3477 addAccelNameImpl(CU, AccelNames, Name, Die);
3478}
3479
3480void DwarfDebug::addAccelObjC(const DICompileUnit &CU, StringRef Name,
3481 const DIE &Die) {
3482 // ObjC names go only into the Apple accelerator tables.
3483 if (getAccelTableKind() == AccelTableKind::Apple)
3484 addAccelNameImpl(CU, AccelObjC, Name, Die);
3485}
3486
3487void DwarfDebug::addAccelNamespace(const DICompileUnit &CU, StringRef Name,
3488 const DIE &Die) {
3489 addAccelNameImpl(CU, AccelNamespace, Name, Die);
3490}
3491
3492void DwarfDebug::addAccelType(const DICompileUnit &CU, StringRef Name,
3493 const DIE &Die, char Flags) {
3494 addAccelNameImpl(CU, AccelTypes, Name, Die);
3495}
3496
3497uint16_t DwarfDebug::getDwarfVersion() const {
3498 return Asm->OutStreamer->getContext().getDwarfVersion();
3499}
3500
3501dwarf::Form DwarfDebug::getDwarfSectionOffsetForm() const {
3502 if (Asm->getDwarfVersion() >= 4)
3503 return dwarf::Form::DW_FORM_sec_offset;
3504 assert((!Asm->isDwarf64() || (Asm->getDwarfVersion() == 3)) &&((void)0)
3505 "DWARF64 is not defined prior DWARFv3")((void)0);
3506 return Asm->isDwarf64() ? dwarf::Form::DW_FORM_data8
3507 : dwarf::Form::DW_FORM_data4;
3508}
3509
3510const MCSymbol *DwarfDebug::getSectionLabel(const MCSection *S) {
3511 auto I = SectionLabels.find(S);
3512 if (I == SectionLabels.end())
3513 return nullptr;
3514 return I->second;
3515}
3516void DwarfDebug::insertSectionLabel(const MCSymbol *S) {
3517 if (SectionLabels.insert(std::make_pair(&S->getSection(), S)).second)
3518 if (useSplitDwarf() || getDwarfVersion() >= 5)
3519 AddrPool.getIndex(S);
3520}
3521
3522Optional<MD5::MD5Result> DwarfDebug::getMD5AsBytes(const DIFile *File) const {
3523 assert(File)((void)0);
3524 if (getDwarfVersion() < 5)
3525 return None;
3526 Optional<DIFile::ChecksumInfo<StringRef>> Checksum = File->getChecksum();
3527 if (!Checksum || Checksum->Kind != DIFile::CSK_MD5)
3528 return None;
3529
3530 // Convert the string checksum to an MD5Result for the streamer.
3531 // The verifier validates the checksum so we assume it's okay.
3532 // An MD5 checksum is 16 bytes.
3533 std::string ChecksumString = fromHex(Checksum->Value);
3534 MD5::MD5Result CKMem;
3535 std::copy(ChecksumString.begin(), ChecksumString.end(), CKMem.Bytes.data());
3536 return CKMem;
3537}