1 /* Common parts for printing diff output */
3 * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
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.
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.
27 #include <arraylist.h>
28 #include <diff_main.h>
29 #include <diff_output.h>
31 #include "diff_internal.h"
34 get_atom_byte(int *ch, struct diff_atom *atom, off_t off)
38 if (atom->at != NULL) {
43 cur = ftello(atom->root->f);
47 if (cur != atom->pos + off &&
48 fseeko(atom->root->f, atom->pos + off, SEEK_SET) == -1)
51 *ch = fgetc(atom->root->f);
52 if (*ch == EOF && ferror(atom->root->f))
59 diff_output_lines(struct diff_output_info *outinfo, FILE *dest,
60 const char *prefix, struct diff_atom *start_atom,
63 struct diff_atom *atom;
64 off_t outoff = 0, *offp;
67 if (outinfo && outinfo->line_offsets.len > 0) {
68 unsigned int idx = outinfo->line_offsets.len - 1;
69 outoff = outinfo->line_offsets.head[idx];
72 foreach_diff_atom(atom, start_atom, count) {
75 unsigned int len = atom->len;
76 rc = fprintf(dest, "%s", prefix);
81 rc = get_atom_byte(&ch, atom, len - 1);
87 rc = get_atom_byte(&ch, atom, len - 1);
95 for (i = 0; i < len; i++) {
96 rc = get_atom_byte(&ch, atom, i);
99 rc = fprintf(dest, "%c", (unsigned char)ch);
104 rc = fprintf(dest, "\n");
109 ARRAYLIST_ADD(offp, outinfo->line_offsets);
121 diff_output_chunk_left_version(struct diff_output_info **output_info,
123 const struct diff_input_info *info,
124 const struct diff_result *result,
125 const struct diff_chunk_context *cc)
128 struct diff_output_info *outinfo = NULL;
130 if (diff_range_empty(&cc->left))
134 *output_info = diff_output_info_alloc();
135 if (*output_info == NULL)
137 outinfo = *output_info;
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];
145 rc = diff_output_lines(outinfo, dest, "",
146 c->left_start, c->left_count);
156 diff_output_chunk_right_version(struct diff_output_info **output_info,
158 const struct diff_input_info *info,
159 const struct diff_result *result,
160 const struct diff_chunk_context *cc)
163 struct diff_output_info *outinfo = NULL;
165 if (diff_range_empty(&cc->right))
169 *output_info = diff_output_info_alloc();
170 if (*output_info == NULL)
172 outinfo = *output_info;
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];
179 if (c->right_count) {
180 rc = diff_output_lines(outinfo, dest, "", c->right_start,
191 diff_output_trailing_newline_msg(struct diff_output_info *outinfo, FILE *dest,
192 const struct diff_chunk *c)
194 enum diff_chunk_type chunk_type = diff_chunk_type(c);
195 struct diff_atom *atom, *start_atom;
196 unsigned int atom_count;
198 off_t outoff = 0, *offp;
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;
209 /* Locate the last atom. */
212 atom = &start_atom[atom_count - 1];
214 rc = get_atom_byte(&ch, atom, atom->len - 1);
215 if (rc != DIFF_RC_OK)
219 if (outinfo && outinfo->line_offsets.len > 0) {
220 unsigned int idx = outinfo->line_offsets.len - 1;
221 outoff = outinfo->line_offsets.head[idx];
223 rc = fprintf(dest, "\\ No newline at end of file\n");
227 ARRAYLIST_ADD(offp, outinfo->line_offsets);
239 is_function_prototype(const char *buf)
241 return isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$';
244 #define FUNCTION_CONTEXT_SIZE 55
247 diff_output_match_function_prototype(char **prototype,
248 const struct diff_result *result,
249 const struct diff_chunk_context *cc)
251 struct diff_atom *start_atom, *atom;
252 const struct diff_data *data;
253 unsigned char buf[FUNCTION_CONTEXT_SIZE];
258 if (result->left.atoms.len > 0 && cc->left.start > 0) {
259 data = &result->left;
260 start_atom = &data->atoms.head[cc->left.start - 1];
261 } else if (result->right.atoms.len > 0 && cc->right.start > 0) {
262 data = &result->right;
263 start_atom = &data->atoms.head[cc->right.start - 1];
267 diff_data_foreach_atom_backwards_from(start_atom, atom, data) {
268 for (i = 0; i < atom->len && i < sizeof(buf) - 1; i++) {
270 rc = get_atom_byte(&ch, atom, i);
278 if (is_function_prototype(buf)) {
279 *prototype = strdup(buf);
280 if (*prototype == NULL)
289 struct diff_output_info *
290 diff_output_info_alloc(void)
292 struct diff_output_info *output_info;
295 output_info = malloc(sizeof(*output_info));
296 if (output_info != NULL) {
297 ARRAYLIST_INIT(output_info->line_offsets, 128);
298 ARRAYLIST_ADD(offp, output_info->line_offsets);
300 diff_output_info_free(output_info);
309 diff_output_info_free(struct diff_output_info *output_info)
311 ARRAYLIST_FREE(output_info->line_offsets);