/home/ben/Projects/got/tog/../lib/diff_output.c

Bug Summary

File:	tog/../lib/diff_output.c
Warning:	line 270, column 10 Assigned value is garbage or undefined

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd6.9 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name diff_output.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -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 pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/local/lib/clang/11.1.0 -I /home/ben/Projects/got/tog/../include -I /home/ben/Projects/got/tog/../lib -D GOT_LIBEXECDIR=/home/ben/bin -D GOT_VERSION=0.53-current -internal-isystem /usr/local/lib/clang/11.1.0/include -internal-externc-isystem /usr/include -O0 -fdebug-compilation-dir /home/ben/Projects/got/tog/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -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 -o /home/ben/Projects/got/scan/2021-05-28-230913-68537-1 -x c /home/ben/Projects/got/tog/../lib/diff_output.c

1/* Common parts for printing diff output */
2/*
3 * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17 
18#include <ctype.h>
19#include <errno(*__errno()).h>
20#include <stdbool.h>
21#include <stdint.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <unistd.h>
26 
27#include <arraylist.h>
28#include <diff_main.h>
29#include <diff_output.h>
30 
31#include "diff_internal.h"
32 
33static int
34get_atom_byte(int *ch, struct diff_atom *atom, off_t off)
35{
36	off_t cur;
37 
38	if (atom->at != NULL((void *)0)) {
13
←
Assuming field 'at' is equal to NULL→
14
←
Taking false branch→
39		*ch = atom->at[off];
40		return 0;
41	}
42 
43	cur = ftello(atom->root->f);
44	if (cur == -1)
15
←
Assuming the condition is true→
16
←
Taking true branch→
45		return errno(*__errno());
17
←
Returning without writing to '*ch'→
18
←
Returning value, which participates in a condition later→
46 
47	if (cur != atom->pos + off &&
48	    fseeko(atom->root->f, atom->pos + off, SEEK_SET0) == -1)
49		return errno(*__errno());
50 
51	*ch = fgetc(atom->root->f);
52	if (*ch == EOF(-1) && ferror(atom->root->f)(!__isthreaded ? (((atom->root->f)->_flags & 0x0040
) != 0) : (ferror)(atom->root->f)))
53		return errno(*__errno());
54 
55	return 0;
56}
57 
58int
59diff_output_lines(struct diff_output_info *outinfo, FILE *dest,
60		  const char *prefix, struct diff_atom *start_atom,
61		  unsigned int count)
62{
63	struct diff_atom *atom;
64	off_t outoff = 0, *offp;
65	int rc;
66 
67	if (outinfo && outinfo->line_offsets.len > 0) {
68		unsigned int idx = outinfo->line_offsets.len - 1;
69		outoff = outinfo->line_offsets.head[idx];
70	}
71 
72	foreach_diff_atom(atom, start_atom, count)for ((atom) = (start_atom); (atom) && ((atom) >= (
start_atom)) && ((atom) - (start_atom) < (count));
 (atom)++) {
73		off_t outlen = 0;
74		int i, ch;
75		unsigned int len = atom->len;
76		rc = fprintf(dest, "%s", prefix);
77		if (rc < 0)
78			return errno(*__errno());
79		outlen += rc;
80		if (len) {
81			rc = get_atom_byte(&ch, atom, len - 1);
82			if (rc)
83				return rc;
84			if (ch == '\n')
85				len--;
86			if (len) {
87				rc = get_atom_byte(&ch, atom, len - 1);
88				if (rc)
89					return rc;
90				if (ch == '\r')
91					len--;
92			}
93		}
94 
95		for (i = 0; i < len; i++) {
96			rc = get_atom_byte(&ch, atom, i);
97			if (rc)
98				return rc;
99			rc = fprintf(dest, "%c", (unsigned char)ch);
100			if (rc < 0)
101				return errno(*__errno());
102			outlen += rc;
103		}
104		rc = fprintf(dest, "\n");
105		if (rc < 0)
106			return errno(*__errno());
107		outlen += rc;
108		if (outinfo) {
109			ARRAYLIST_ADD(offp, outinfo->line_offsets)do { if ((outinfo->line_offsets).len && !(outinfo->
line_offsets).allocated) { offp = ((void *)0); break; } if ((
outinfo->line_offsets).head == ((void *)0) || (outinfo->
line_offsets).allocated < (outinfo->line_offsets).len +
 1) { (outinfo->line_offsets).p = recallocarray((outinfo->
line_offsets).head, (outinfo->line_offsets).len, (outinfo->
line_offsets).allocated + ((outinfo->line_offsets).alloc_blocksize
 ? : 8), sizeof(*(outinfo->line_offsets).head)); if ((outinfo
->line_offsets).p == ((void *)0)) { offp = ((void *)0); break
; } (outinfo->line_offsets).allocated += (outinfo->line_offsets
).alloc_blocksize ? : 8; (outinfo->line_offsets).head = (outinfo
->line_offsets).p; (outinfo->line_offsets).p = ((void *
)0); }; if ((outinfo->line_offsets).head == ((void *)0) ||
 (outinfo->line_offsets).allocated < (outinfo->line_offsets
).len + 1) { offp = ((void *)0); break; } (offp) = &(outinfo
->line_offsets).head[(outinfo->line_offsets).len]; (outinfo
->line_offsets).len++; } while (0);
110			if (offp == NULL((void *)0))
111				return ENOMEM12;
112			outoff += outlen;
113			*offp = outoff;
114		}
115	}
116 
117	return DIFF_RC_OK0;
118}
119 
120int
121diff_output_chunk_left_version(struct diff_output_info **output_info,
122			       FILE *dest,
123			       const struct diff_input_info *info,
124			       const struct diff_result *result,
125			       const struct diff_chunk_context *cc)
126{
127	int rc, c_idx;
128	struct diff_output_info *outinfo = NULL((void *)0);
129 
130	if (diff_range_empty(&cc->left))
131		return DIFF_RC_OK0;
132 
133	if (output_info) {
134		*output_info = diff_output_info_alloc();
135		if (*output_info == NULL((void *)0))
136			return ENOMEM12;
137		outinfo = *output_info;
138	}
139 
140	/* Write out all chunks on the left side. */
141	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
142		const struct diff_chunk *c = &result->chunks.head[c_idx];
143 
144		if (c->left_count) {
145			rc = diff_output_lines(outinfo, dest, "",
146			    c->left_start, c->left_count);
147			if (rc)
148				return rc;
149		}
150	}
151 
152	return DIFF_RC_OK0;
153}
154 
155int
156diff_output_chunk_right_version(struct diff_output_info **output_info,
157				FILE *dest,
158				const struct diff_input_info *info,
159				const struct diff_result *result,
160				const struct diff_chunk_context *cc)
161{
162	int rc, c_idx;
163	struct diff_output_info *outinfo = NULL((void *)0);
164 
165	if (diff_range_empty(&cc->right))
166		return DIFF_RC_OK0;
167 
168	if (output_info) {
169		*output_info = diff_output_info_alloc();
170		if (*output_info == NULL((void *)0))
171			return ENOMEM12;
172		outinfo = *output_info;
173	}
174 
175	/* Write out all chunks on the right side. */
176	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
177		const struct diff_chunk *c = &result->chunks.head[c_idx];
178 
179		if (c->right_count) {
180			rc = diff_output_lines(outinfo, dest, "", c->right_start,
181			    c->right_count);
182			if (rc)
183				return rc;
184		}
185	}
186 
187	return DIFF_RC_OK0;
188}
189 
190int
191diff_output_trailing_newline_msg(struct diff_output_info *outinfo, FILE *dest,
192				 const struct diff_chunk *c)
193{
194	enum diff_chunk_type chunk_type = diff_chunk_type(c);
195	struct diff_atom *atom, *start_atom;
196	unsigned int atom_count;
197	int rc, ch;
198	off_t outoff = 0, *offp;
199 
200	if (chunk_type == CHUNK_MINUS || chunk_type == CHUNK_SAME) {
201		start_atom = c->left_start;
202		atom_count = c->left_count;
203	} else if (chunk_type == CHUNK_PLUS) {
204		start_atom = c->right_start;
205		atom_count = c->right_count;
206	} else
207		return EINVAL22;
208 
209	/* Locate the last atom. */
210	if (atom_count == 0)
211		return EINVAL22;
212	atom = &start_atom[atom_count - 1];
213 
214	rc = get_atom_byte(&ch, atom, atom->len - 1);
215	if (rc != DIFF_RC_OK0)
216		return rc;
217 
218	if (ch != '\n') {
219		if (outinfo && outinfo->line_offsets.len > 0) {
220			unsigned int idx = outinfo->line_offsets.len - 1;
221			outoff = outinfo->line_offsets.head[idx];
222		}
223		rc = fprintf(dest, "\\ No newline at end of file\n");
224		if (rc < 0)
225			return errno(*__errno());
226		if (outinfo) {
227			ARRAYLIST_ADD(offp, outinfo->line_offsets)do { if ((outinfo->line_offsets).len && !(outinfo->
line_offsets).allocated) { offp = ((void *)0); break; } if ((
outinfo->line_offsets).head == ((void *)0) || (outinfo->
line_offsets).allocated < (outinfo->line_offsets).len +
 1) { (outinfo->line_offsets).p = recallocarray((outinfo->
line_offsets).head, (outinfo->line_offsets).len, (outinfo->
line_offsets).allocated + ((outinfo->line_offsets).alloc_blocksize
 ? : 8), sizeof(*(outinfo->line_offsets).head)); if ((outinfo
->line_offsets).p == ((void *)0)) { offp = ((void *)0); break
; } (outinfo->line_offsets).allocated += (outinfo->line_offsets
).alloc_blocksize ? : 8; (outinfo->line_offsets).head = (outinfo
->line_offsets).p; (outinfo->line_offsets).p = ((void *
)0); }; if ((outinfo->line_offsets).head == ((void *)0) ||
 (outinfo->line_offsets).allocated < (outinfo->line_offsets
).len + 1) { offp = ((void *)0); break; } (offp) = &(outinfo
->line_offsets).head[(outinfo->line_offsets).len]; (outinfo
->line_offsets).len++; } while (0);
228			if (offp == NULL((void *)0))
229				return ENOMEM12;
230			outoff += rc;
231			*offp = outoff;
232		}
233	}
234 
235	return DIFF_RC_OK0;
236}
237 
238static bool_Bool
239is_function_prototype(unsigned char ch)
240{
241	return (isalpha(ch) || ch == '_' || ch == '$');
242}
243 
244#define begins_with(s, pre)(strncmp(s, pre, sizeof(pre)-1) == 0) (strncmp(s, pre, sizeof(pre)-1) == 0)
245 
246int
247diff_output_match_function_prototype(char *prototype, size_t prototype_size,
248    int *last_prototype_idx, const struct diff_result *result,
249    const struct diff_chunk_context *cc)
250{
251	struct diff_atom *start_atom, *atom;
252	const struct diff_data *data;
253	unsigned char buf[DIFF_FUNCTION_CONTEXT_SIZE55];
254	char *state = NULL((void *)0);
255	int rc, i, ch;
1
'ch' declared without an initial value→
256 
257	if (result->left->atoms.len > 0 && cc->left.start > 0) {
2
←
Assuming field 'len' is > 0→
3
←
Assuming field 'start' is > 0→
4
←
Taking true branch→
258		data = result->left;
259		start_atom = &data->atoms.head[cc->left.start - 1];
260	} else
261		return DIFF_RC_OK0;
262 
263	diff_data_foreach_atom_backwards_from(start_atom, atom, data)for ((atom) = (start_atom); (atom) && ((atom) >= (
data)->atoms.head) && ((atom) - (data)->atoms.head
 >= 0); (atom)--) {
5
←
Assuming 'atom' is non-null→
6
←
Assuming 'atom' is >= field 'head'→
7
←
Loop condition is true.  Entering loop body→
264		int atom_idx = diff_atom_root_idx(data, atom)((atom) && ((atom) >= (data)->root->atoms.head
) ? (unsigned int)((atom) - ((data)->root->atoms.head))
 : (data)->root->atoms.len);
8
←
Assuming 'atom' is < field 'head'→
9
←
'?' condition is false→
265		if (atom_idx < *last_prototype_idx)
10
←
Assuming the condition is false→
11
←
Taking false branch→
266			break;
267		rc = get_atom_byte(&ch, atom, 0);
12
←
Calling 'get_atom_byte'→
19
←
Returning from 'get_atom_byte'→
268		if (rc)
20
←
Assuming 'rc' is 0→
21
←
Taking false branch→
269			return rc;
270		buf[0] = (unsigned char)ch;
22
←
Assigned value is garbage or undefined
271		if (!is_function_prototype(buf[0]))
272			continue;
273		for (i = 1; i < atom->len && i < sizeof(buf) - 1; i++) {
274			rc = get_atom_byte(&ch, atom, i);
275			if (rc)
276				return rc;
277			if (ch == '\n')
278				break;
279			buf[i] = (unsigned char)ch;
280		}
281		buf[i] = '\0';
282		if (begins_with(buf, "private:")(strncmp(buf, "private:", sizeof("private:")-1) == 0)) {
283			if (!state)
284				state = " (private)";
285		} else if (begins_with(buf, "protected:")(strncmp(buf, "protected:", sizeof("protected:")-1) == 0)) {
286			if (!state)
287				state = " (protected)";
288		} else if (begins_with(buf, "public:")(strncmp(buf, "public:", sizeof("public:")-1) == 0)) {
289			if (!state)
290				state = " (public)";
291		} else {
292			if (state)  /* don't care about truncation */
293				strlcat(buf, state, sizeof(buf));
294			strlcpy(prototype, buf, prototype_size);
295			break;
296		}
297	}
298 
299	*last_prototype_idx = diff_atom_root_idx(data, start_atom)((start_atom) && ((start_atom) >= (data)->root->
atoms.head) ? (unsigned int)((start_atom) - ((data)->root->
atoms.head)) : (data)->root->atoms.len);
300	return DIFF_RC_OK0;
301}
302 
303struct diff_output_info *
304diff_output_info_alloc(void)
305{
306	struct diff_output_info *output_info;
307	off_t *offp;
308 
309	output_info = malloc(sizeof(*output_info));
310	if (output_info != NULL((void *)0)) {
311		ARRAYLIST_INIT(output_info->line_offsets, 128)do { (output_info->line_offsets).head = ((void *)0); (output_info
->line_offsets).len = 0; (output_info->line_offsets).allocated
 = 0; (output_info->line_offsets).alloc_blocksize = 128; }
 while(0);
312		ARRAYLIST_ADD(offp, output_info->line_offsets)do { if ((output_info->line_offsets).len && !(output_info
->line_offsets).allocated) { offp = ((void *)0); break; } if
 ((output_info->line_offsets).head == ((void *)0) || (output_info
->line_offsets).allocated < (output_info->line_offsets
).len + 1) { (output_info->line_offsets).p = recallocarray
((output_info->line_offsets).head, (output_info->line_offsets
).len, (output_info->line_offsets).allocated + ((output_info
->line_offsets).alloc_blocksize ? : 8), sizeof(*(output_info
->line_offsets).head)); if ((output_info->line_offsets)
.p == ((void *)0)) { offp = ((void *)0); break; } (output_info
->line_offsets).allocated += (output_info->line_offsets
).alloc_blocksize ? : 8; (output_info->line_offsets).head =
 (output_info->line_offsets).p; (output_info->line_offsets
).p = ((void *)0); }; if ((output_info->line_offsets).head
 == ((void *)0) || (output_info->line_offsets).allocated <
 (output_info->line_offsets).len + 1) { offp = ((void *)0)
; break; } (offp) = &(output_info->line_offsets).head[
(output_info->line_offsets).len]; (output_info->line_offsets
).len++; } while (0);
313		if (offp == NULL((void *)0)) {
314			diff_output_info_free(output_info);
315			return NULL((void *)0);
316		}
317		*offp = 0;
318	}
319	return output_info;
320}
321 
322void
323diff_output_info_free(struct diff_output_info *output_info)
324{
325	ARRAYLIST_FREE(output_info->line_offsets)do { if ((output_info->line_offsets).head && (output_info
->line_offsets).allocated) free((output_info->line_offsets
).head); do { (output_info->line_offsets).head = ((void *)
0); (output_info->line_offsets).len = 0; (output_info->
line_offsets).allocated = 0; (output_info->line_offsets).alloc_blocksize
 = (output_info->line_offsets).alloc_blocksize; } while(0)
; } while(0);
326	free(output_info);
327}
328 
329const char *
330diff_output_get_label_left(const struct diff_input_info *info)
331{
332	if (info->flags & DIFF_INPUT_LEFT_NONEXISTENT0x00000001)
333		return "/dev/null";
334 
335	return info->left_path ? : "a";
336}
337 
338const char *
339diff_output_get_label_right(const struct diff_input_info *info)
340{
341	if (info->flags & DIFF_INPUT_RIGHT_NONEXISTENT0x00000002)
342		return "/dev/null";
343 
344	return info->right_path ? : "b";
345}