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))
58 #define DIFF_OUTPUT_BUF_SIZE 512
61 diff_output_lines(struct diff_output_info *outinfo, FILE *dest,
62 const char *prefix, struct diff_atom *start_atom,
65 struct diff_atom *atom;
66 off_t outoff = 0, *offp;
69 if (outinfo && outinfo->line_offsets.len > 0) {
70 unsigned int idx = outinfo->line_offsets.len - 1;
71 outoff = outinfo->line_offsets.head[idx];
74 foreach_diff_atom(atom, start_atom, count) {
77 unsigned int len = atom->len;
78 unsigned char buf[DIFF_OUTPUT_BUF_SIZE + 1 /* '\n' */];
81 n = strlcpy(buf, prefix, sizeof(buf));
82 if (n >= DIFF_OUTPUT_BUF_SIZE) /* leave room for '\n' */
87 rc = get_atom_byte(&ch, atom, len - 1);
93 rc = get_atom_byte(&ch, atom, len - 1);
101 for (i = 0; i < len; i++) {
102 rc = get_atom_byte(&ch, atom, i);
105 if (nbuf >= DIFF_OUTPUT_BUF_SIZE) {
106 rc = fwrite(buf, 1, nbuf, dest);
115 rc = fwrite(buf, 1, nbuf, dest);
120 ARRAYLIST_ADD(offp, outinfo->line_offsets);
132 diff_output_chunk_left_version(struct diff_output_info **output_info,
134 const struct diff_input_info *info,
135 const struct diff_result *result,
136 const struct diff_chunk_context *cc)
139 struct diff_output_info *outinfo = NULL;
141 if (diff_range_empty(&cc->left))
145 *output_info = diff_output_info_alloc();
146 if (*output_info == NULL)
148 outinfo = *output_info;
151 /* Write out all chunks on the left side. */
152 for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
153 const struct diff_chunk *c = &result->chunks.head[c_idx];
156 rc = diff_output_lines(outinfo, dest, "",
157 c->left_start, c->left_count);
167 diff_output_chunk_right_version(struct diff_output_info **output_info,
169 const struct diff_input_info *info,
170 const struct diff_result *result,
171 const struct diff_chunk_context *cc)
174 struct diff_output_info *outinfo = NULL;
176 if (diff_range_empty(&cc->right))
180 *output_info = diff_output_info_alloc();
181 if (*output_info == NULL)
183 outinfo = *output_info;
186 /* Write out all chunks on the right side. */
187 for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
188 const struct diff_chunk *c = &result->chunks.head[c_idx];
190 if (c->right_count) {
191 rc = diff_output_lines(outinfo, dest, "", c->right_start,
202 diff_output_trailing_newline_msg(struct diff_output_info *outinfo, FILE *dest,
203 const struct diff_chunk *c)
205 enum diff_chunk_type chunk_type = diff_chunk_type(c);
206 struct diff_atom *atom, *start_atom;
207 unsigned int atom_count;
209 off_t outoff = 0, *offp;
211 if (chunk_type == CHUNK_MINUS || chunk_type == CHUNK_SAME) {
212 start_atom = c->left_start;
213 atom_count = c->left_count;
214 } else if (chunk_type == CHUNK_PLUS) {
215 start_atom = c->right_start;
216 atom_count = c->right_count;
220 /* Locate the last atom. */
223 atom = &start_atom[atom_count - 1];
225 rc = get_atom_byte(&ch, atom, atom->len - 1);
226 if (rc != DIFF_RC_OK)
230 if (outinfo && outinfo->line_offsets.len > 0) {
231 unsigned int idx = outinfo->line_offsets.len - 1;
232 outoff = outinfo->line_offsets.head[idx];
234 rc = fprintf(dest, "\\ No newline at end of file\n");
238 ARRAYLIST_ADD(offp, outinfo->line_offsets);
250 is_function_prototype(unsigned char ch)
252 return (isalpha(ch) || ch == '_' || ch == '$');
255 #define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0)
258 diff_output_match_function_prototype(char *prototype, size_t prototype_size,
259 int *last_prototype_idx, const struct diff_result *result,
260 const struct diff_chunk_context *cc)
262 struct diff_atom *start_atom, *atom;
263 const struct diff_data *data;
264 unsigned char buf[DIFF_FUNCTION_CONTEXT_SIZE];
268 if (result->left->atoms.len > 0 && cc->left.start > 0) {
270 start_atom = &data->atoms.head[cc->left.start - 1];
274 diff_data_foreach_atom_backwards_from(start_atom, atom, data) {
275 int atom_idx = diff_atom_root_idx(data, atom);
276 if (atom_idx < *last_prototype_idx)
278 rc = get_atom_byte(&ch, atom, 0);
281 buf[0] = (unsigned char)ch;
282 if (!is_function_prototype(buf[0]))
284 for (i = 1; i < atom->len && i < sizeof(buf) - 1; i++) {
285 rc = get_atom_byte(&ch, atom, i);
290 buf[i] = (unsigned char)ch;
293 if (begins_with(buf, "private:")) {
295 state = " (private)";
296 } else if (begins_with(buf, "protected:")) {
298 state = " (protected)";
299 } else if (begins_with(buf, "public:")) {
303 if (state) /* don't care about truncation */
304 strlcat(buf, state, sizeof(buf));
305 strlcpy(prototype, buf, prototype_size);
310 *last_prototype_idx = diff_atom_root_idx(data, start_atom);
314 struct diff_output_info *
315 diff_output_info_alloc(void)
317 struct diff_output_info *output_info;
320 output_info = malloc(sizeof(*output_info));
321 if (output_info != NULL) {
322 ARRAYLIST_INIT(output_info->line_offsets, 128);
323 ARRAYLIST_ADD(offp, output_info->line_offsets);
325 diff_output_info_free(output_info);
334 diff_output_info_free(struct diff_output_info *output_info)
336 ARRAYLIST_FREE(output_info->line_offsets);
341 diff_output_get_label_left(const struct diff_input_info *info)
343 if (info->flags & DIFF_INPUT_LEFT_NONEXISTENT)
346 return info->left_path ? : "a";
350 diff_output_get_label_right(const struct diff_input_info *info)
352 if (info->flags & DIFF_INPUT_RIGHT_NONEXISTENT)
355 return info->right_path ? : "b";