Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
Warning:line 454, column 25
4th function call argument is an uninitialized value

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ExternalFunctions.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/ExecutionEngine/Interpreter/ExternalFunctions.cpp
1//===-- ExternalFunctions.cpp - Implement External Functions --------------===//
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 both code to deal with invoking "external" functions, but
10// also contains code that implements "exported" external functions.
11//
12// There are currently two mechanisms for handling external functions in the
13// Interpreter. The first is to implement lle_* wrapper functions that are
14// specific to well-known library functions which manually translate the
15// arguments from GenericValues and make the call. If such a wrapper does
16// not exist, and libffi is available, then the Interpreter will attempt to
17// invoke the function using libffi, after finding its address.
18//
19//===----------------------------------------------------------------------===//
20
21#include "Interpreter.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/ArrayRef.h"
24#include "llvm/Config/config.h" // Detect libffi
25#include "llvm/ExecutionEngine/GenericValue.h"
26#include "llvm/IR/DataLayout.h"
27#include "llvm/IR/DerivedTypes.h"
28#include "llvm/IR/Function.h"
29#include "llvm/IR/Type.h"
30#include "llvm/Support/Casting.h"
31#include "llvm/Support/DynamicLibrary.h"
32#include "llvm/Support/ErrorHandling.h"
33#include "llvm/Support/ManagedStatic.h"
34#include "llvm/Support/Mutex.h"
35#include "llvm/Support/raw_ostream.h"
36#include <cassert>
37#include <cmath>
38#include <csignal>
39#include <cstdint>
40#include <cstdio>
41#include <cstring>
42#include <map>
43#include <mutex>
44#include <string>
45#include <utility>
46#include <vector>
47
48#ifdef HAVE_FFI_CALL
49#ifdef HAVE_FFI_H
50#include <ffi.h>
51#define USE_LIBFFI
52#elif HAVE_FFI_FFI_H
53#include <ffi/ffi.h>
54#define USE_LIBFFI
55#endif
56#endif
57
58using namespace llvm;
59
60static ManagedStatic<sys::Mutex> FunctionsLock;
61
62typedef GenericValue (*ExFunc)(FunctionType *, ArrayRef<GenericValue>);
63static ManagedStatic<std::map<const Function *, ExFunc> > ExportedFunctions;
64static ManagedStatic<std::map<std::string, ExFunc> > FuncNames;
65
66#ifdef USE_LIBFFI
67typedef void (*RawFunc)();
68static ManagedStatic<std::map<const Function *, RawFunc> > RawFunctions;
69#endif
70
71static Interpreter *TheInterpreter;
72
73static char getTypeID(Type *Ty) {
74 switch (Ty->getTypeID()) {
75 case Type::VoidTyID: return 'V';
76 case Type::IntegerTyID:
77 switch (cast<IntegerType>(Ty)->getBitWidth()) {
78 case 1: return 'o';
79 case 8: return 'B';
80 case 16: return 'S';
81 case 32: return 'I';
82 case 64: return 'L';
83 default: return 'N';
84 }
85 case Type::FloatTyID: return 'F';
86 case Type::DoubleTyID: return 'D';
87 case Type::PointerTyID: return 'P';
88 case Type::FunctionTyID:return 'M';
89 case Type::StructTyID: return 'T';
90 case Type::ArrayTyID: return 'A';
91 default: return 'U';
92 }
93}
94
95// Try to find address of external function given a Function object.
96// Please note, that interpreter doesn't know how to assemble a
97// real call in general case (this is JIT job), that's why it assumes,
98// that all external functions has the same (and pretty "general") signature.
99// The typical example of such functions are "lle_X_" ones.
100static ExFunc lookupFunction(const Function *F) {
101 // Function not found, look it up... start by figuring out what the
102 // composite function name should be.
103 std::string ExtName = "lle_";
104 FunctionType *FT = F->getFunctionType();
105 ExtName += getTypeID(FT->getReturnType());
106 for (Type *T : FT->params())
107 ExtName += getTypeID(T);
108 ExtName += ("_" + F->getName()).str();
109
110 sys::ScopedLock Writer(*FunctionsLock);
111 ExFunc FnPtr = (*FuncNames)[ExtName];
112 if (!FnPtr)
113 FnPtr = (*FuncNames)[("lle_X_" + F->getName()).str()];
114 if (!FnPtr) // Try calling a generic function... if it exists...
115 FnPtr = (ExFunc)(intptr_t)sys::DynamicLibrary::SearchForAddressOfSymbol(
116 ("lle_X_" + F->getName()).str());
117 if (FnPtr)
118 ExportedFunctions->insert(std::make_pair(F, FnPtr)); // Cache for later
119 return FnPtr;
120}
121
122#ifdef USE_LIBFFI
123static ffi_type *ffiTypeFor(Type *Ty) {
124 switch (Ty->getTypeID()) {
125 case Type::VoidTyID: return &ffi_type_void;
126 case Type::IntegerTyID:
127 switch (cast<IntegerType>(Ty)->getBitWidth()) {
128 case 8: return &ffi_type_sint8;
129 case 16: return &ffi_type_sint16;
130 case 32: return &ffi_type_sint32;
131 case 64: return &ffi_type_sint64;
132 }
133 llvm_unreachable("Unhandled integer type bitwidth")__builtin_unreachable();
134 case Type::FloatTyID: return &ffi_type_float;
135 case Type::DoubleTyID: return &ffi_type_double;
136 case Type::PointerTyID: return &ffi_type_pointer;
137 default: break;
138 }
139 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
140 report_fatal_error("Type could not be mapped for use with libffi.");
141 return NULL__null;
142}
143
144static void *ffiValueFor(Type *Ty, const GenericValue &AV,
145 void *ArgDataPtr) {
146 switch (Ty->getTypeID()) {
147 case Type::IntegerTyID:
148 switch (cast<IntegerType>(Ty)->getBitWidth()) {
149 case 8: {
150 int8_t *I8Ptr = (int8_t *) ArgDataPtr;
151 *I8Ptr = (int8_t) AV.IntVal.getZExtValue();
152 return ArgDataPtr;
153 }
154 case 16: {
155 int16_t *I16Ptr = (int16_t *) ArgDataPtr;
156 *I16Ptr = (int16_t) AV.IntVal.getZExtValue();
157 return ArgDataPtr;
158 }
159 case 32: {
160 int32_t *I32Ptr = (int32_t *) ArgDataPtr;
161 *I32Ptr = (int32_t) AV.IntVal.getZExtValue();
162 return ArgDataPtr;
163 }
164 case 64: {
165 int64_t *I64Ptr = (int64_t *) ArgDataPtr;
166 *I64Ptr = (int64_t) AV.IntVal.getZExtValue();
167 return ArgDataPtr;
168 }
169 }
170 llvm_unreachable("Unhandled integer type bitwidth")__builtin_unreachable();
171 case Type::FloatTyID: {
172 float *FloatPtr = (float *) ArgDataPtr;
173 *FloatPtr = AV.FloatVal;
174 return ArgDataPtr;
175 }
176 case Type::DoubleTyID: {
177 double *DoublePtr = (double *) ArgDataPtr;
178 *DoublePtr = AV.DoubleVal;
179 return ArgDataPtr;
180 }
181 case Type::PointerTyID: {
182 void **PtrPtr = (void **) ArgDataPtr;
183 *PtrPtr = GVTOP(AV);
184 return ArgDataPtr;
185 }
186 default: break;
187 }
188 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
189 report_fatal_error("Type value could not be mapped for use with libffi.");
190 return NULL__null;
191}
192
193static bool ffiInvoke(RawFunc Fn, Function *F, ArrayRef<GenericValue> ArgVals,
194 const DataLayout &TD, GenericValue &Result) {
195 ffi_cif cif;
196 FunctionType *FTy = F->getFunctionType();
197 const unsigned NumArgs = F->arg_size();
198
199 // TODO: We don't have type information about the remaining arguments, because
200 // this information is never passed into ExecutionEngine::runFunction().
201 if (ArgVals.size() > NumArgs && F->isVarArg()) {
202 report_fatal_error("Calling external var arg function '" + F->getName()
203 + "' is not supported by the Interpreter.");
204 }
205
206 unsigned ArgBytes = 0;
207
208 std::vector<ffi_type*> args(NumArgs);
209 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
210 A != E; ++A) {
211 const unsigned ArgNo = A->getArgNo();
212 Type *ArgTy = FTy->getParamType(ArgNo);
213 args[ArgNo] = ffiTypeFor(ArgTy);
214 ArgBytes += TD.getTypeStoreSize(ArgTy);
215 }
216
217 SmallVector<uint8_t, 128> ArgData;
218 ArgData.resize(ArgBytes);
219 uint8_t *ArgDataPtr = ArgData.data();
220 SmallVector<void*, 16> values(NumArgs);
221 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
222 A != E; ++A) {
223 const unsigned ArgNo = A->getArgNo();
224 Type *ArgTy = FTy->getParamType(ArgNo);
225 values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr);
226 ArgDataPtr += TD.getTypeStoreSize(ArgTy);
227 }
228
229 Type *RetTy = FTy->getReturnType();
230 ffi_type *rtype = ffiTypeFor(RetTy);
231
232 if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, args.data()) ==
233 FFI_OK) {
234 SmallVector<uint8_t, 128> ret;
235 if (RetTy->getTypeID() != Type::VoidTyID)
236 ret.resize(TD.getTypeStoreSize(RetTy));
237 ffi_call(&cif, Fn, ret.data(), values.data());
238 switch (RetTy->getTypeID()) {
239 case Type::IntegerTyID:
240 switch (cast<IntegerType>(RetTy)->getBitWidth()) {
241 case 8: Result.IntVal = APInt(8 , *(int8_t *) ret.data()); break;
242 case 16: Result.IntVal = APInt(16, *(int16_t*) ret.data()); break;
243 case 32: Result.IntVal = APInt(32, *(int32_t*) ret.data()); break;
244 case 64: Result.IntVal = APInt(64, *(int64_t*) ret.data()); break;
245 }
246 break;
247 case Type::FloatTyID: Result.FloatVal = *(float *) ret.data(); break;
248 case Type::DoubleTyID: Result.DoubleVal = *(double*) ret.data(); break;
249 case Type::PointerTyID: Result.PointerVal = *(void **) ret.data(); break;
250 default: break;
251 }
252 return true;
253 }
254
255 return false;
256}
257#endif // USE_LIBFFI
258
259GenericValue Interpreter::callExternalFunction(Function *F,
260 ArrayRef<GenericValue> ArgVals) {
261 TheInterpreter = this;
262
263 std::unique_lock<sys::Mutex> Guard(*FunctionsLock);
264
265 // Do a lookup to see if the function is in our cache... this should just be a
266 // deferred annotation!
267 std::map<const Function *, ExFunc>::iterator FI = ExportedFunctions->find(F);
268 if (ExFunc Fn = (FI == ExportedFunctions->end()) ? lookupFunction(F)
269 : FI->second) {
270 Guard.unlock();
271 return Fn(F->getFunctionType(), ArgVals);
272 }
273
274#ifdef USE_LIBFFI
275 std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F);
276 RawFunc RawFn;
277 if (RF == RawFunctions->end()) {
278 RawFn = (RawFunc)(intptr_t)
279 sys::DynamicLibrary::SearchForAddressOfSymbol(std::string(F->getName()));
280 if (!RawFn)
281 RawFn = (RawFunc)(intptr_t)getPointerToGlobalIfAvailable(F);
282 if (RawFn != 0)
283 RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later
284 } else {
285 RawFn = RF->second;
286 }
287
288 Guard.unlock();
289
290 GenericValue Result;
291 if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getDataLayout(), Result))
292 return Result;
293#endif // USE_LIBFFI
294
295 if (F->getName() == "__main")
296 errs() << "Tried to execute an unknown external function: "
297 << *F->getType() << " __main\n";
298 else
299 report_fatal_error("Tried to execute an unknown external function: " +
300 F->getName());
301#ifndef USE_LIBFFI
302 errs() << "Recompiling LLVM with --enable-libffi might help.\n";
303#endif
304 return GenericValue();
305}
306
307//===----------------------------------------------------------------------===//
308// Functions "exported" to the running application...
309//
310
311// void atexit(Function*)
312static GenericValue lle_X_atexit(FunctionType *FT,
313 ArrayRef<GenericValue> Args) {
314 assert(Args.size() == 1)((void)0);
315 TheInterpreter->addAtExitHandler((Function*)GVTOP(Args[0]));
316 GenericValue GV;
317 GV.IntVal = 0;
318 return GV;
319}
320
321// void exit(int)
322static GenericValue lle_X_exit(FunctionType *FT, ArrayRef<GenericValue> Args) {
323 TheInterpreter->exitCalled(Args[0]);
324 return GenericValue();
325}
326
327// void abort(void)
328static GenericValue lle_X_abort(FunctionType *FT, ArrayRef<GenericValue> Args) {
329 //FIXME: should we report or raise here?
330 //report_fatal_error("Interpreted program raised SIGABRT");
331 raise (SIGABRT6);
332 return GenericValue();
333}
334
335// int sprintf(char *, const char *, ...) - a very rough implementation to make
336// output useful.
337static GenericValue lle_X_sprintf(FunctionType *FT,
338 ArrayRef<GenericValue> Args) {
339 char *OutputBuffer = (char *)GVTOP(Args[0]);
340 const char *FmtStr = (const char *)GVTOP(Args[1]);
341 unsigned ArgNo = 2;
342
343 // printf should return # chars printed. This is completely incorrect, but
344 // close enough for now.
345 GenericValue GV;
346 GV.IntVal = APInt(32, strlen(FmtStr));
347 while (true) {
348 switch (*FmtStr) {
349 case 0: return GV; // Null terminator...
350 default: // Normal nonspecial character
351 sprintf(OutputBuffer++, "%c", *FmtStr++);
352 break;
353 case '\\': { // Handle escape codes
354 sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
355 FmtStr += 2; OutputBuffer += 2;
356 break;
357 }
358 case '%': { // Handle format specifiers
359 char FmtBuf[100] = "", Buffer[1000] = "";
360 char *FB = FmtBuf;
361 *FB++ = *FmtStr++;
362 char Last = *FB++ = *FmtStr++;
363 unsigned HowLong = 0;
364 while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
365 Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
366 Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
367 Last != 'p' && Last != 's' && Last != '%') {
368 if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's
369 Last = *FB++ = *FmtStr++;
370 }
371 *FB = 0;
372
373 switch (Last) {
374 case '%':
375 memcpy(Buffer, "%", 2); break;
376 case 'c':
377 sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
378 break;
379 case 'd': case 'i':
380 case 'u': case 'o':
381 case 'x': case 'X':
382 if (HowLong >= 1) {
383 if (HowLong == 1 &&
384 TheInterpreter->getDataLayout().getPointerSizeInBits() == 64 &&
385 sizeof(long) < sizeof(int64_t)) {
386 // Make sure we use %lld with a 64 bit argument because we might be
387 // compiling LLI on a 32 bit compiler.
388 unsigned Size = strlen(FmtBuf);
389 FmtBuf[Size] = FmtBuf[Size-1];
390 FmtBuf[Size+1] = 0;
391 FmtBuf[Size-1] = 'l';
392 }
393 sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue());
394 } else
395 sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
396 break;
397 case 'e': case 'E': case 'g': case 'G': case 'f':
398 sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
399 case 'p':
400 sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break;
401 case 's':
402 sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break;
403 default:
404 errs() << "<unknown printf code '" << *FmtStr << "'!>";
405 ArgNo++; break;
406 }
407 size_t Len = strlen(Buffer);
408 memcpy(OutputBuffer, Buffer, Len + 1);
409 OutputBuffer += Len;
410 }
411 break;
412 }
413 }
414 return GV;
415}
416
417// int printf(const char *, ...) - a very rough implementation to make output
418// useful.
419static GenericValue lle_X_printf(FunctionType *FT,
420 ArrayRef<GenericValue> Args) {
421 char Buffer[10000];
422 std::vector<GenericValue> NewArgs;
423 NewArgs.push_back(PTOGV((void*)&Buffer[0]));
424 llvm::append_range(NewArgs, Args);
425 GenericValue GV = lle_X_sprintf(FT, NewArgs);
426 outs() << Buffer;
427 return GV;
428}
429
430// int sscanf(const char *format, ...);
431static GenericValue lle_X_sscanf(FunctionType *FT,
432 ArrayRef<GenericValue> args) {
433 assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!")((void)0);
434
435 char *Args[10];
436 for (unsigned i = 0; i < args.size(); ++i)
437 Args[i] = (char*)GVTOP(args[i]);
438
439 GenericValue GV;
440 GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
441 Args[5], Args[6], Args[7], Args[8], Args[9]));
442 return GV;
443}
444
445// int scanf(const char *format, ...);
446static GenericValue lle_X_scanf(FunctionType *FT, ArrayRef<GenericValue> args) {
447 assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!")((void)0);
448
449 char *Args[10];
450 for (unsigned i = 0; i < args.size(); ++i)
1
Assuming the condition is true
→
2
←
Loop condition is true. Entering loop body
→
3
←
Assuming the condition is true
→
4
←
Loop condition is true. Entering loop body
→
5
←
Assuming the condition is true
→
6
←
Loop condition is true. Entering loop body
→
7
←
Assuming the condition is false
→
8
←
Loop condition is false. Execution continues on line 453
→
451 Args[i] = (char*)GVTOP(args[i]);
452
453 GenericValue GV;
454 GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4],
9
←
4th function call argument is an uninitialized value
455 Args[5], Args[6], Args[7], Args[8], Args[9]));
456 return GV;
457}
458
459// int fprintf(FILE *, const char *, ...) - a very rough implementation to make
460// output useful.
461static GenericValue lle_X_fprintf(FunctionType *FT,
462 ArrayRef<GenericValue> Args) {
463 assert(Args.size() >= 2)((void)0);
464 char Buffer[10000];
465 std::vector<GenericValue> NewArgs;
466 NewArgs.push_back(PTOGV(Buffer));
467 NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
468 GenericValue GV = lle_X_sprintf(FT, NewArgs);
469
470 fputs(Buffer, (FILE *) GVTOP(Args[0]));
471 return GV;
472}
473
474static GenericValue lle_X_memset(FunctionType *FT,
475 ArrayRef<GenericValue> Args) {
476 int val = (int)Args[1].IntVal.getSExtValue();
477 size_t len = (size_t)Args[2].IntVal.getZExtValue();
478 memset((void *)GVTOP(Args[0]), val, len);
479 // llvm.memset.* returns void, lle_X_* returns GenericValue,
480 // so here we return GenericValue with IntVal set to zero
481 GenericValue GV;
482 GV.IntVal = 0;
483 return GV;
484}
485
486static GenericValue lle_X_memcpy(FunctionType *FT,
487 ArrayRef<GenericValue> Args) {
488 memcpy(GVTOP(Args[0]), GVTOP(Args[1]),
489 (size_t)(Args[2].IntVal.getLimitedValue()));
490
491 // llvm.memcpy* returns void, lle_X_* returns GenericValue,
492 // so here we return GenericValue with IntVal set to zero
493 GenericValue GV;
494 GV.IntVal = 0;
495 return GV;
496}
497
498void Interpreter::initializeExternalFunctions() {
499 sys::ScopedLock Writer(*FunctionsLock);
500 (*FuncNames)["lle_X_atexit"] = lle_X_atexit;
501 (*FuncNames)["lle_X_exit"] = lle_X_exit;
502 (*FuncNames)["lle_X_abort"] = lle_X_abort;
503
504 (*FuncNames)["lle_X_printf"] = lle_X_printf;
505 (*FuncNames)["lle_X_sprintf"] = lle_X_sprintf;
506 (*FuncNames)["lle_X_sscanf"] = lle_X_sscanf;
507 (*FuncNames)["lle_X_scanf"] = lle_X_scanf;
508 (*FuncNames)["lle_X_fprintf"] = lle_X_fprintf;
509 (*FuncNames)["lle_X_memset"] = lle_X_memset;
510 (*FuncNames)["lle_X_memcpy"] = lle_X_memcpy;
511}