1 fe621944 2020-11-10 stsp /* Produce a unidiff output from a diff_result. */
  2 fe621944 2020-11-10 stsp /*
  3 fe621944 2020-11-10 stsp  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
  4 fe621944 2020-11-10 stsp  *
  5 fe621944 2020-11-10 stsp  * Permission to use, copy, modify, and distribute this software for any
  6 fe621944 2020-11-10 stsp  * purpose with or without fee is hereby granted, provided that the above
  7 fe621944 2020-11-10 stsp  * copyright notice and this permission notice appear in all copies.
  8 fe621944 2020-11-10 stsp  *
  9 fe621944 2020-11-10 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 10 fe621944 2020-11-10 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 11 fe621944 2020-11-10 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 12 fe621944 2020-11-10 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 13 fe621944 2020-11-10 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 14 fe621944 2020-11-10 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 15 fe621944 2020-11-10 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 16 fe621944 2020-11-10 stsp  */
 17 fe621944 2020-11-10 stsp 
 18 fe621944 2020-11-10 stsp #include <errno.h>
 19 fe621944 2020-11-10 stsp #include <stdbool.h>
 20 f3c44083 2020-11-14 naddy #include <stdint.h>
 21 fe621944 2020-11-10 stsp #include <stdio.h>
 22 fe621944 2020-11-10 stsp #include <stdlib.h>
 23 f3b2b552 2020-12-10 stsp #include <string.h>
 24 fe621944 2020-11-10 stsp #include <assert.h>
 25 fe621944 2020-11-10 stsp 
 26 fe621944 2020-11-10 stsp #include <arraylist.h>
 27 fe621944 2020-11-10 stsp #include <diff_main.h>
 28 fe621944 2020-11-10 stsp #include <diff_output.h>
 29 fe621944 2020-11-10 stsp 
 30 fe621944 2020-11-10 stsp #include "diff_internal.h"
 31 fe621944 2020-11-10 stsp #include "diff_debug.h"
 32 fe621944 2020-11-10 stsp 
 33 fe621944 2020-11-10 stsp bool
 34 fe621944 2020-11-10 stsp diff_chunk_context_empty(const struct diff_chunk_context *cc)
 35 fe621944 2020-11-10 stsp {
 36 fe621944 2020-11-10 stsp 	return diff_range_empty(&cc->chunk);
 37 fe621944 2020-11-10 stsp }
 38 fe621944 2020-11-10 stsp 
 39 fe621944 2020-11-10 stsp int
 40 fe621944 2020-11-10 stsp diff_chunk_get_left_start(const struct diff_chunk *c,
 41 fe621944 2020-11-10 stsp     const struct diff_result *r, int context_lines)
 42 fe621944 2020-11-10 stsp {
 43 fe621944 2020-11-10 stsp 	int left_start = diff_atom_root_idx(r->left, c->left_start);
 44 fe621944 2020-11-10 stsp 	return MAX(0, left_start - context_lines);
 45 fe621944 2020-11-10 stsp }
 46 fe621944 2020-11-10 stsp 
 47 fe621944 2020-11-10 stsp int
 48 fe621944 2020-11-10 stsp diff_chunk_get_left_end(const struct diff_chunk *c,
 49 fe621944 2020-11-10 stsp     const struct diff_result *r, int context_lines)
 50 fe621944 2020-11-10 stsp {
 51 fe621944 2020-11-10 stsp 	int left_start = diff_chunk_get_left_start(c, r, 0);
 52 fe621944 2020-11-10 stsp 	return MIN(r->left->atoms.len,
 53 fe621944 2020-11-10 stsp 	    left_start + c->left_count + context_lines);
 54 fe621944 2020-11-10 stsp }
 55 fe621944 2020-11-10 stsp 
 56 fe621944 2020-11-10 stsp int
 57 fe621944 2020-11-10 stsp diff_chunk_get_right_start(const struct diff_chunk *c,
 58 fe621944 2020-11-10 stsp     const struct diff_result *r, int context_lines)
 59 fe621944 2020-11-10 stsp {
 60 fe621944 2020-11-10 stsp 	int right_start = diff_atom_root_idx(r->right, c->right_start);
 61 fe621944 2020-11-10 stsp 	return MAX(0, right_start - context_lines);
 62 fe621944 2020-11-10 stsp }
 63 fe621944 2020-11-10 stsp 
 64 fe621944 2020-11-10 stsp int
 65 fe621944 2020-11-10 stsp diff_chunk_get_right_end(const struct diff_chunk *c,
 66 fe621944 2020-11-10 stsp     const struct diff_result *r, int context_lines)
 67 fe621944 2020-11-10 stsp {
 68 fe621944 2020-11-10 stsp 	int right_start = diff_chunk_get_right_start(c, r, 0);
 69 fe621944 2020-11-10 stsp 	return MIN(r->right->atoms.len,
 70 fe621944 2020-11-10 stsp 	    right_start + c->right_count + context_lines);
 71 fe621944 2020-11-10 stsp }
 72 fe621944 2020-11-10 stsp 
 73 fe621944 2020-11-10 stsp struct diff_chunk *
 74 fe621944 2020-11-10 stsp diff_chunk_get(const struct diff_result *r, int chunk_idx)
 75 fe621944 2020-11-10 stsp {
 76 fe621944 2020-11-10 stsp 	return &r->chunks.head[chunk_idx];
 77 fe621944 2020-11-10 stsp }
 78 fe621944 2020-11-10 stsp 
 79 fe621944 2020-11-10 stsp int
 80 fe621944 2020-11-10 stsp diff_chunk_get_left_count(struct diff_chunk *c)
 81 fe621944 2020-11-10 stsp {
 82 fe621944 2020-11-10 stsp 	return c->left_count;
 83 fe621944 2020-11-10 stsp }
 84 fe621944 2020-11-10 stsp 
 85 fe621944 2020-11-10 stsp int
 86 fe621944 2020-11-10 stsp diff_chunk_get_right_count(struct diff_chunk *c)
 87 fe621944 2020-11-10 stsp {
 88 fe621944 2020-11-10 stsp 	return c->right_count;
 89 fe621944 2020-11-10 stsp }
 90 fe621944 2020-11-10 stsp 
 91 fe621944 2020-11-10 stsp void
 92 fe621944 2020-11-10 stsp diff_chunk_context_get(struct diff_chunk_context *cc, const struct diff_result *r,
 93 fe621944 2020-11-10 stsp 		  int chunk_idx, int context_lines)
 94 fe621944 2020-11-10 stsp {
 95 fe621944 2020-11-10 stsp 	const struct diff_chunk *c = &r->chunks.head[chunk_idx];
 96 fe621944 2020-11-10 stsp 	int left_start = diff_chunk_get_left_start(c, r, context_lines);
 97 fe621944 2020-11-10 stsp 	int left_end = diff_chunk_get_left_end(c, r, context_lines);
 98 fe621944 2020-11-10 stsp 	int right_start = diff_chunk_get_right_start(c, r, context_lines);
 99 fe621944 2020-11-10 stsp 	int right_end = diff_chunk_get_right_end(c, r,  context_lines);
100 fe621944 2020-11-10 stsp 
101 fe621944 2020-11-10 stsp 	*cc = (struct diff_chunk_context){
102 fe621944 2020-11-10 stsp 		.chunk = {
103 fe621944 2020-11-10 stsp 			.start = chunk_idx,
104 fe621944 2020-11-10 stsp 			.end = chunk_idx + 1,
105 fe621944 2020-11-10 stsp 		},
106 fe621944 2020-11-10 stsp 		.left = {
107 fe621944 2020-11-10 stsp 			.start = left_start,
108 fe621944 2020-11-10 stsp 			.end = left_end,
109 fe621944 2020-11-10 stsp 		},
110 fe621944 2020-11-10 stsp 		.right = {
111 fe621944 2020-11-10 stsp 			.start = right_start,
112 fe621944 2020-11-10 stsp 			.end = right_end,
113 fe621944 2020-11-10 stsp 		},
114 fe621944 2020-11-10 stsp 	};
115 fe621944 2020-11-10 stsp }
116 fe621944 2020-11-10 stsp 
117 fe621944 2020-11-10 stsp bool
118 fe621944 2020-11-10 stsp diff_chunk_contexts_touch(const struct diff_chunk_context *cc,
119 fe621944 2020-11-10 stsp 			  const struct diff_chunk_context *other)
120 fe621944 2020-11-10 stsp {
121 fe621944 2020-11-10 stsp 	return diff_ranges_touch(&cc->chunk, &other->chunk)
122 fe621944 2020-11-10 stsp 		|| diff_ranges_touch(&cc->left, &other->left)
123 fe621944 2020-11-10 stsp 		|| diff_ranges_touch(&cc->right, &other->right);
124 fe621944 2020-11-10 stsp }
125 fe621944 2020-11-10 stsp 
126 fe621944 2020-11-10 stsp void
127 fe621944 2020-11-10 stsp diff_chunk_contexts_merge(struct diff_chunk_context *cc,
128 fe621944 2020-11-10 stsp 			  const struct diff_chunk_context *other)
129 fe621944 2020-11-10 stsp {
130 fe621944 2020-11-10 stsp 	diff_ranges_merge(&cc->chunk, &other->chunk);
131 fe621944 2020-11-10 stsp 	diff_ranges_merge(&cc->left, &other->left);
132 fe621944 2020-11-10 stsp 	diff_ranges_merge(&cc->right, &other->right);
133 fe621944 2020-11-10 stsp }
134 fe621944 2020-11-10 stsp 
135 fe621944 2020-11-10 stsp void
136 fe621944 2020-11-10 stsp diff_chunk_context_load_change(struct diff_chunk_context *cc,
137 fe621944 2020-11-10 stsp 			       int *nchunks_used,
138 fe621944 2020-11-10 stsp 			       struct diff_result *result,
139 fe621944 2020-11-10 stsp 			       int start_chunk_idx,
140 fe621944 2020-11-10 stsp 			       int context_lines)
141 fe621944 2020-11-10 stsp {
142 fe621944 2020-11-10 stsp 	int i;
143 fe621944 2020-11-10 stsp 	int seen_minus = 0, seen_plus = 0;
144 fe621944 2020-11-10 stsp 
145 fe621944 2020-11-10 stsp 	if (nchunks_used)
146 fe621944 2020-11-10 stsp 		*nchunks_used = 0;
147 fe621944 2020-11-10 stsp 
148 fe621944 2020-11-10 stsp 	for (i = start_chunk_idx; i < result->chunks.len; i++) {
149 fe621944 2020-11-10 stsp 		struct diff_chunk *chunk = &result->chunks.head[i];
150 fe621944 2020-11-10 stsp 		enum diff_chunk_type t = diff_chunk_type(chunk);
151 fe621944 2020-11-10 stsp 		struct diff_chunk_context next;
152 fe621944 2020-11-10 stsp 
153 fe621944 2020-11-10 stsp 		if (t != CHUNK_MINUS && t != CHUNK_PLUS) {
154 fe621944 2020-11-10 stsp 			if (nchunks_used)
155 fe621944 2020-11-10 stsp 				(*nchunks_used)++;
156 fe621944 2020-11-10 stsp 			if (seen_minus || seen_plus)
157 fe621944 2020-11-10 stsp 				break;
158 fe621944 2020-11-10 stsp 			else
159 fe621944 2020-11-10 stsp 				continue;
160 fe621944 2020-11-10 stsp 		} else if (t == CHUNK_MINUS)
161 fe621944 2020-11-10 stsp 			seen_minus = 1;
162 fe621944 2020-11-10 stsp 		else if (t == CHUNK_PLUS)
163 fe621944 2020-11-10 stsp 			seen_plus = 1;
164 fe621944 2020-11-10 stsp 
165 fe621944 2020-11-10 stsp 		if (diff_chunk_context_empty(cc)) {
166 fe621944 2020-11-10 stsp 			/* Note down the start point, any number of subsequent
167 fe621944 2020-11-10 stsp 			 * chunks may be joined up to this chunk by being
168 fe621944 2020-11-10 stsp 			 * directly adjacent. */
169 fe621944 2020-11-10 stsp 			diff_chunk_context_get(cc, result, i, context_lines);
170 fe621944 2020-11-10 stsp 			if (nchunks_used)
171 fe621944 2020-11-10 stsp 				(*nchunks_used)++;
172 fe621944 2020-11-10 stsp 			continue;
173 fe621944 2020-11-10 stsp 		}
174 fe621944 2020-11-10 stsp 
175 fe621944 2020-11-10 stsp 		/* There already is a previous chunk noted down for being
176 fe621944 2020-11-10 stsp 		 * printed. Does it join up with this one? */
177 fe621944 2020-11-10 stsp 		diff_chunk_context_get(&next, result, i, context_lines);
178 fe621944 2020-11-10 stsp 
179 fe621944 2020-11-10 stsp 		if (diff_chunk_contexts_touch(cc, &next)) {
180 fe621944 2020-11-10 stsp 			/* This next context touches or overlaps the previous
181 fe621944 2020-11-10 stsp 			 * one, join. */
182 fe621944 2020-11-10 stsp 			diff_chunk_contexts_merge(cc, &next);
183 fe621944 2020-11-10 stsp 			if (nchunks_used)
184 fe621944 2020-11-10 stsp 				(*nchunks_used)++;
185 fe621944 2020-11-10 stsp 			continue;
186 fe621944 2020-11-10 stsp 		} else
187 fe621944 2020-11-10 stsp 			break;
188 fe621944 2020-11-10 stsp 	}
189 fe621944 2020-11-10 stsp }
190 fe621944 2020-11-10 stsp 
191 fe621944 2020-11-10 stsp struct diff_output_unidiff_state {
192 fe621944 2020-11-10 stsp 	bool header_printed;
193 f3b2b552 2020-12-10 stsp 	char prototype[DIFF_FUNCTION_CONTEXT_SIZE];
194 f3b2b552 2020-12-10 stsp 	int last_prototype_idx;
195 fe621944 2020-11-10 stsp };
196 fe621944 2020-11-10 stsp 
197 fe621944 2020-11-10 stsp struct diff_output_unidiff_state *
198 fe621944 2020-11-10 stsp diff_output_unidiff_state_alloc(void)
199 fe621944 2020-11-10 stsp {
200 fe621944 2020-11-10 stsp 	struct diff_output_unidiff_state *state;
201 fe621944 2020-11-10 stsp 
202 fe621944 2020-11-10 stsp 	state = calloc(1, sizeof(struct diff_output_unidiff_state));
203 fe621944 2020-11-10 stsp 	if (state != NULL)
204 fe621944 2020-11-10 stsp 		diff_output_unidiff_state_reset(state);
205 fe621944 2020-11-10 stsp 	return state;
206 fe621944 2020-11-10 stsp }
207 fe621944 2020-11-10 stsp 
208 fe621944 2020-11-10 stsp void
209 fe621944 2020-11-10 stsp diff_output_unidiff_state_reset(struct diff_output_unidiff_state *state)
210 fe621944 2020-11-10 stsp {
211 fe621944 2020-11-10 stsp 	state->header_printed = false;
212 f3b2b552 2020-12-10 stsp 	memset(state->prototype, 0, sizeof(state->prototype));
213 f3b2b552 2020-12-10 stsp 	state->last_prototype_idx = 0;
214 fe621944 2020-11-10 stsp }
215 fe621944 2020-11-10 stsp 
216 fe621944 2020-11-10 stsp void
217 fe621944 2020-11-10 stsp diff_output_unidiff_state_free(struct diff_output_unidiff_state *state)
218 fe621944 2020-11-10 stsp {
219 fe621944 2020-11-10 stsp 	free(state);
220 fe621944 2020-11-10 stsp }
221 fe621944 2020-11-10 stsp 
222 fe621944 2020-11-10 stsp static int
223 fe621944 2020-11-10 stsp output_unidiff_chunk(struct diff_output_info *outinfo, FILE *dest,
224 fe621944 2020-11-10 stsp 		     struct diff_output_unidiff_state *state,
225 fe621944 2020-11-10 stsp 		     const struct diff_input_info *info,
226 fe621944 2020-11-10 stsp 		     const struct diff_result *result,
227 fe621944 2020-11-10 stsp 		     bool print_header, bool show_function_prototypes,
228 fe621944 2020-11-10 stsp 		     const struct diff_chunk_context *cc)
229 fe621944 2020-11-10 stsp {
230 fe621944 2020-11-10 stsp 	int rc, left_start, left_len, right_start, right_len;
231 fe621944 2020-11-10 stsp 	off_t outoff = 0, *offp;
232 fe621944 2020-11-10 stsp 
233 fe621944 2020-11-10 stsp 	if (diff_range_empty(&cc->left) && diff_range_empty(&cc->right))
234 fe621944 2020-11-10 stsp 		return DIFF_RC_OK;
235 fe621944 2020-11-10 stsp 
236 fe621944 2020-11-10 stsp 	if (outinfo && outinfo->line_offsets.len > 0) {
237 fe621944 2020-11-10 stsp 		unsigned int idx = outinfo->line_offsets.len - 1;
238 fe621944 2020-11-10 stsp 		outoff = outinfo->line_offsets.head[idx];
239 fe621944 2020-11-10 stsp 	}
240 fe621944 2020-11-10 stsp 
241 fe621944 2020-11-10 stsp 	if (print_header && !(state->header_printed)) {
242 c4cd9c5b 2020-11-21 stsp 		rc = fprintf(dest, "--- %s\n",
243 c4cd9c5b 2020-11-21 stsp 		    diff_output_get_label_left(info));
244 fe621944 2020-11-10 stsp 		if (rc < 0)
245 fe621944 2020-11-10 stsp 			return errno;
246 fe621944 2020-11-10 stsp 		if (outinfo) {
247 fe621944 2020-11-10 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
248 fe621944 2020-11-10 stsp 			if (offp == NULL)
249 fe621944 2020-11-10 stsp 				return ENOMEM;
250 fe621944 2020-11-10 stsp 			outoff += rc;
251 fe621944 2020-11-10 stsp 			*offp = outoff;
252 fe621944 2020-11-10 stsp 
253 fe621944 2020-11-10 stsp 		}
254 c4cd9c5b 2020-11-21 stsp 		rc = fprintf(dest, "+++ %s\n",
255 c4cd9c5b 2020-11-21 stsp 		    diff_output_get_label_right(info));
256 fe621944 2020-11-10 stsp 		if (rc < 0)
257 fe621944 2020-11-10 stsp 			return errno;
258 fe621944 2020-11-10 stsp 		if (outinfo) {
259 fe621944 2020-11-10 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
260 fe621944 2020-11-10 stsp 			if (offp == NULL)
261 fe621944 2020-11-10 stsp 				return ENOMEM;
262 fe621944 2020-11-10 stsp 			outoff += rc;
263 fe621944 2020-11-10 stsp 			*offp = outoff;
264 fe621944 2020-11-10 stsp 
265 fe621944 2020-11-10 stsp 		}
266 fe621944 2020-11-10 stsp 		state->header_printed = true;
267 fe621944 2020-11-10 stsp 	}
268 fe621944 2020-11-10 stsp 
269 fe621944 2020-11-10 stsp 	left_len = cc->left.end - cc->left.start;
270 fe621944 2020-11-10 stsp 	if (result->left->atoms.len == 0)
271 fe621944 2020-11-10 stsp 		left_start = 0;
272 fe621944 2020-11-10 stsp 	else if (left_len == 0 && cc->left.start > 0)
273 fe621944 2020-11-10 stsp 		left_start = cc->left.start;
274 fe621944 2020-11-10 stsp 	else
275 fe621944 2020-11-10 stsp 		left_start = cc->left.start + 1;
276 fe621944 2020-11-10 stsp 
277 fe621944 2020-11-10 stsp 	right_len = cc->right.end - cc->right.start;
278 fe621944 2020-11-10 stsp 	if (result->right->atoms.len == 0)
279 fe621944 2020-11-10 stsp 		right_start = 0;
280 fe621944 2020-11-10 stsp 	else if (right_len == 0 && cc->right.start > 0)
281 fe621944 2020-11-10 stsp 		right_start = cc->right.start;
282 fe621944 2020-11-10 stsp 	else
283 fe621944 2020-11-10 stsp 		right_start = cc->right.start + 1;
284 fe621944 2020-11-10 stsp 
285 fe621944 2020-11-10 stsp 	if (show_function_prototypes) {
286 f3b2b552 2020-12-10 stsp 		rc = diff_output_match_function_prototype(state->prototype,
287 f3b2b552 2020-12-10 stsp 		    sizeof(state->prototype), &state->last_prototype_idx,
288 fe621944 2020-11-10 stsp 		    result, cc);
289 fe621944 2020-11-10 stsp 		if (rc)
290 fe621944 2020-11-10 stsp 			return rc;
291 fe621944 2020-11-10 stsp 	}
292 fe621944 2020-11-10 stsp 
293 fe621944 2020-11-10 stsp 	if (left_len == 1 && right_len == 1) {
294 fe621944 2020-11-10 stsp 		rc = fprintf(dest, "@@ -%d +%d @@%s%s\n",
295 fe621944 2020-11-10 stsp 			left_start, right_start,
296 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? " " : "",
297 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? state->prototype : "");
298 fe621944 2020-11-10 stsp 	} else if (left_len == 1 && right_len != 1) {
299 fe621944 2020-11-10 stsp 		rc = fprintf(dest, "@@ -%d +%d,%d @@%s%s\n",
300 fe621944 2020-11-10 stsp 			left_start, right_start, right_len,
301 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? " " : "",
302 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? state->prototype : "");
303 fe621944 2020-11-10 stsp 	} else if (left_len != 1 && right_len == 1) {
304 fe621944 2020-11-10 stsp 		rc = fprintf(dest, "@@ -%d,%d +%d @@%s%s\n",
305 fe621944 2020-11-10 stsp 			left_start, left_len, right_start,
306 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? " " : "",
307 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? state->prototype : "");
308 fe621944 2020-11-10 stsp 	} else {
309 fe621944 2020-11-10 stsp 		rc = fprintf(dest, "@@ -%d,%d +%d,%d @@%s%s\n",
310 fe621944 2020-11-10 stsp 			left_start, left_len, right_start, right_len,
311 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? " " : "",
312 f3b2b552 2020-12-10 stsp 			state->prototype[0] ? state->prototype : "");
313 fe621944 2020-11-10 stsp 	}
314 fe621944 2020-11-10 stsp 	if (rc < 0)
315 fe621944 2020-11-10 stsp 		return errno;
316 fe621944 2020-11-10 stsp 	if (outinfo) {
317 fe621944 2020-11-10 stsp 		ARRAYLIST_ADD(offp, outinfo->line_offsets);
318 fe621944 2020-11-10 stsp 		if (offp == NULL)
319 fe621944 2020-11-10 stsp 			return ENOMEM;
320 fe621944 2020-11-10 stsp 		outoff += rc;
321 fe621944 2020-11-10 stsp 		*offp = outoff;
322 fe621944 2020-11-10 stsp 
323 fe621944 2020-11-10 stsp 	}
324 fe621944 2020-11-10 stsp 
325 fe621944 2020-11-10 stsp 	/* Got the absolute line numbers where to start printing, and the index
326 fe621944 2020-11-10 stsp 	 * of the interesting (non-context) chunk.
327 fe621944 2020-11-10 stsp 	 * To print context lines above the interesting chunk, nipping on the
328 fe621944 2020-11-10 stsp 	 * previous chunk index may be necessary.
329 fe621944 2020-11-10 stsp 	 * It is guaranteed to be only context lines where left == right, so it
330 fe621944 2020-11-10 stsp 	 * suffices to look on the left. */
331 fe621944 2020-11-10 stsp 	const struct diff_chunk *first_chunk;
332 fe621944 2020-11-10 stsp 	int chunk_start_line;
333 fe621944 2020-11-10 stsp 	first_chunk = &result->chunks.head[cc->chunk.start];
334 fe621944 2020-11-10 stsp 	chunk_start_line = diff_atom_root_idx(result->left,
335 fe621944 2020-11-10 stsp 					      first_chunk->left_start);
336 fe621944 2020-11-10 stsp 	if (cc->left.start < chunk_start_line) {
337 fe621944 2020-11-10 stsp 		rc = diff_output_lines(outinfo, dest, " ",
338 fe621944 2020-11-10 stsp 				  &result->left->atoms.head[cc->left.start],
339 fe621944 2020-11-10 stsp 				  chunk_start_line - cc->left.start);
340 fe621944 2020-11-10 stsp 		if (rc)
341 fe621944 2020-11-10 stsp 			return rc;
342 fe621944 2020-11-10 stsp 	}
343 fe621944 2020-11-10 stsp 
344 fe621944 2020-11-10 stsp 	/* Now write out all the joined chunks and contexts between them */
345 fe621944 2020-11-10 stsp 	int c_idx;
346 fe621944 2020-11-10 stsp 	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
347 fe621944 2020-11-10 stsp 		const struct diff_chunk *c = &result->chunks.head[c_idx];
348 fe621944 2020-11-10 stsp 
349 fe621944 2020-11-10 stsp 		if (c->left_count && c->right_count)
350 fe621944 2020-11-10 stsp 			rc = diff_output_lines(outinfo, dest,
351 fe621944 2020-11-10 stsp 					  c->solved ? " " : "?",
352 fe621944 2020-11-10 stsp 					  c->left_start, c->left_count);
353 fe621944 2020-11-10 stsp 		else if (c->left_count && !c->right_count)
354 fe621944 2020-11-10 stsp 			rc = diff_output_lines(outinfo, dest,
355 fe621944 2020-11-10 stsp 					  c->solved ? "-" : "?",
356 fe621944 2020-11-10 stsp 					  c->left_start, c->left_count);
357 fe621944 2020-11-10 stsp 		else if (c->right_count && !c->left_count)
358 fe621944 2020-11-10 stsp 			rc = diff_output_lines(outinfo, dest,
359 fe621944 2020-11-10 stsp 					  c->solved ? "+" : "?",
360 fe621944 2020-11-10 stsp 					  c->right_start, c->right_count);
361 fe621944 2020-11-10 stsp 		if (rc)
362 fe621944 2020-11-10 stsp 			return rc;
363 fe621944 2020-11-10 stsp 
364 fe621944 2020-11-10 stsp 		if (cc->chunk.end == result->chunks.len) {
365 fe621944 2020-11-10 stsp 			rc = diff_output_trailing_newline_msg(outinfo, dest, c);
366 fe621944 2020-11-10 stsp 			if (rc != DIFF_RC_OK)
367 fe621944 2020-11-10 stsp 				return rc;
368 fe621944 2020-11-10 stsp 		}
369 fe621944 2020-11-10 stsp 	}
370 fe621944 2020-11-10 stsp 
371 fe621944 2020-11-10 stsp 	/* Trailing context? */
372 fe621944 2020-11-10 stsp 	const struct diff_chunk *last_chunk;
373 fe621944 2020-11-10 stsp 	int chunk_end_line;
374 fe621944 2020-11-10 stsp 	last_chunk = &result->chunks.head[cc->chunk.end - 1];
375 fe621944 2020-11-10 stsp 	chunk_end_line = diff_atom_root_idx(result->left,
376 fe621944 2020-11-10 stsp 					    last_chunk->left_start
377 fe621944 2020-11-10 stsp 					    + last_chunk->left_count);
378 fe621944 2020-11-10 stsp 	if (cc->left.end > chunk_end_line) {
379 fe621944 2020-11-10 stsp 		rc = diff_output_lines(outinfo, dest, " ",
380 fe621944 2020-11-10 stsp 				  &result->left->atoms.head[chunk_end_line],
381 fe621944 2020-11-10 stsp 				  cc->left.end - chunk_end_line);
382 fe621944 2020-11-10 stsp 		if (rc)
383 fe621944 2020-11-10 stsp 			return rc;
384 fe621944 2020-11-10 stsp 	}
385 fe621944 2020-11-10 stsp 
386 fe621944 2020-11-10 stsp 	return DIFF_RC_OK;
387 fe621944 2020-11-10 stsp }
388 fe621944 2020-11-10 stsp 
389 fe621944 2020-11-10 stsp int
390 fe621944 2020-11-10 stsp diff_output_unidiff_chunk(struct diff_output_info **output_info, FILE *dest,
391 fe621944 2020-11-10 stsp 			  struct diff_output_unidiff_state *state,
392 fe621944 2020-11-10 stsp 			  const struct diff_input_info *info,
393 fe621944 2020-11-10 stsp 			  const struct diff_result *result,
394 fe621944 2020-11-10 stsp 			  const struct diff_chunk_context *cc)
395 fe621944 2020-11-10 stsp {
396 fe621944 2020-11-10 stsp 	struct diff_output_info *outinfo = NULL;
397 fe621944 2020-11-10 stsp 	int flags = (result->left->root->diff_flags |
398 fe621944 2020-11-10 stsp 	    result->right->root->diff_flags);
399 fe621944 2020-11-10 stsp 	bool show_function_prototypes = (flags & DIFF_FLAG_SHOW_PROTOTYPES);
400 fe621944 2020-11-10 stsp 
401 fe621944 2020-11-10 stsp 	if (output_info) {
402 fe621944 2020-11-10 stsp 		*output_info = diff_output_info_alloc();
403 fe621944 2020-11-10 stsp 		if (*output_info == NULL)
404 fe621944 2020-11-10 stsp 			return ENOMEM;
405 fe621944 2020-11-10 stsp 		outinfo = *output_info;
406 fe621944 2020-11-10 stsp 	}
407 fe621944 2020-11-10 stsp 
408 fe621944 2020-11-10 stsp 	return output_unidiff_chunk(outinfo, dest, state, info,
409 fe621944 2020-11-10 stsp 	    result, false, show_function_prototypes, cc);
410 fe621944 2020-11-10 stsp }
411 fe621944 2020-11-10 stsp 
412 fe621944 2020-11-10 stsp int
413 fe621944 2020-11-10 stsp diff_output_unidiff(struct diff_output_info **output_info,
414 fe621944 2020-11-10 stsp 		    FILE *dest, const struct diff_input_info *info,
415 fe621944 2020-11-10 stsp 		    const struct diff_result *result,
416 fe621944 2020-11-10 stsp 		    unsigned int context_lines)
417 fe621944 2020-11-10 stsp {
418 fe621944 2020-11-10 stsp 	struct diff_output_unidiff_state *state;
419 fe621944 2020-11-10 stsp 	struct diff_chunk_context cc = {};
420 fe621944 2020-11-10 stsp 	struct diff_output_info *outinfo = NULL;
421 b67f3bcb 2020-11-21 stsp 	int atomizer_flags = (result->left->atomizer_flags|
422 b67f3bcb 2020-11-21 stsp 	    result->right->atomizer_flags);
423 fe621944 2020-11-10 stsp 	int flags = (result->left->root->diff_flags |
424 fe621944 2020-11-10 stsp 	    result->right->root->diff_flags);
425 fe621944 2020-11-10 stsp 	bool show_function_prototypes = (flags & DIFF_FLAG_SHOW_PROTOTYPES);
426 b67f3bcb 2020-11-21 stsp 	bool force_text = (flags & DIFF_FLAG_FORCE_TEXT_DATA);
427 b67f3bcb 2020-11-21 stsp 	bool have_binary = (atomizer_flags & DIFF_ATOMIZER_FOUND_BINARY_DATA);
428 2471f5c4 2022-01-06 stsp 	off_t outoff = 0, *offp;
429 2471f5c4 2022-01-06 stsp 	int rc, i;
430 fe621944 2020-11-10 stsp 
431 fe621944 2020-11-10 stsp 	if (!result)
432 fe621944 2020-11-10 stsp 		return EINVAL;
433 fe621944 2020-11-10 stsp 	if (result->rc != DIFF_RC_OK)
434 fe621944 2020-11-10 stsp 		return result->rc;
435 fe621944 2020-11-10 stsp 
436 fe621944 2020-11-10 stsp 	if (output_info) {
437 fe621944 2020-11-10 stsp 		*output_info = diff_output_info_alloc();
438 fe621944 2020-11-10 stsp 		if (*output_info == NULL)
439 fe621944 2020-11-10 stsp 			return ENOMEM;
440 fe621944 2020-11-10 stsp 		outinfo = *output_info;
441 fe621944 2020-11-10 stsp 	}
442 b67f3bcb 2020-11-21 stsp 
443 b67f3bcb 2020-11-21 stsp 	if (have_binary && !force_text) {
444 b67f3bcb 2020-11-21 stsp 		for (i = 0; i < result->chunks.len; i++) {
445 b67f3bcb 2020-11-21 stsp 			struct diff_chunk *c = &result->chunks.head[i];
446 b67f3bcb 2020-11-21 stsp 			enum diff_chunk_type t = diff_chunk_type(c);
447 fe621944 2020-11-10 stsp 
448 b67f3bcb 2020-11-21 stsp 			if (t != CHUNK_MINUS && t != CHUNK_PLUS)
449 b67f3bcb 2020-11-21 stsp 				continue;
450 b67f3bcb 2020-11-21 stsp 
451 2471f5c4 2022-01-06 stsp 			if (outinfo && outinfo->line_offsets.len > 0) {
452 2471f5c4 2022-01-06 stsp 				unsigned int idx =
453 2471f5c4 2022-01-06 stsp 				    outinfo->line_offsets.len - 1;
454 2471f5c4 2022-01-06 stsp 				outoff = outinfo->line_offsets.head[idx];
455 2471f5c4 2022-01-06 stsp 			}
456 2471f5c4 2022-01-06 stsp 
457 2471f5c4 2022-01-06 stsp 			rc = fprintf(dest, "Binary files %s and %s differ\n",
458 c4cd9c5b 2020-11-21 stsp 			    diff_output_get_label_left(info),
459 c4cd9c5b 2020-11-21 stsp 			    diff_output_get_label_right(info));
460 2471f5c4 2022-01-06 stsp 			if (outinfo) {
461 2471f5c4 2022-01-06 stsp 				ARRAYLIST_ADD(offp, outinfo->line_offsets);
462 2471f5c4 2022-01-06 stsp 				if (offp == NULL)
463 2471f5c4 2022-01-06 stsp 					return ENOMEM;
464 2471f5c4 2022-01-06 stsp 				outoff += rc;
465 2471f5c4 2022-01-06 stsp 				*offp = outoff;
466 2471f5c4 2022-01-06 stsp 
467 2471f5c4 2022-01-06 stsp 			}
468 b67f3bcb 2020-11-21 stsp 			break;
469 b67f3bcb 2020-11-21 stsp 		}
470 b67f3bcb 2020-11-21 stsp 
471 b67f3bcb 2020-11-21 stsp 		return DIFF_RC_OK;
472 b67f3bcb 2020-11-21 stsp 	}
473 b67f3bcb 2020-11-21 stsp 
474 fe621944 2020-11-10 stsp 	state = diff_output_unidiff_state_alloc();
475 fe621944 2020-11-10 stsp 	if (state == NULL) {
476 fe621944 2020-11-10 stsp 		if (output_info) {
477 fe621944 2020-11-10 stsp 			diff_output_info_free(*output_info);
478 fe621944 2020-11-10 stsp 			*output_info = NULL;
479 fe621944 2020-11-10 stsp 		}
480 fe621944 2020-11-10 stsp 		return ENOMEM;
481 fe621944 2020-11-10 stsp 	}
482 fe621944 2020-11-10 stsp 
483 fe621944 2020-11-10 stsp #if DEBUG
484 fe621944 2020-11-10 stsp 	unsigned int check_left_pos, check_right_pos;
485 fe621944 2020-11-10 stsp 	check_left_pos = 0;
486 fe621944 2020-11-10 stsp 	check_right_pos = 0;
487 fe621944 2020-11-10 stsp 	for (i = 0; i < result->chunks.len; i++) {
488 fe621944 2020-11-10 stsp 		struct diff_chunk *c = &result->chunks.head[i];
489 fe621944 2020-11-10 stsp 		enum diff_chunk_type t = diff_chunk_type(c);
490 fe621944 2020-11-10 stsp 
491 fe621944 2020-11-10 stsp 		debug("[%d] %s lines L%d R%d @L %d @R %d\n",
492 fe621944 2020-11-10 stsp 		      i, (t == CHUNK_MINUS ? "minus" :
493 fe621944 2020-11-10 stsp 			  (t == CHUNK_PLUS ? "plus" :
494 fe621944 2020-11-10 stsp 			   (t == CHUNK_SAME ? "same" : "?"))),
495 fe621944 2020-11-10 stsp 		      c->left_count,
496 fe621944 2020-11-10 stsp 		      c->right_count,
497 fe621944 2020-11-10 stsp 		      c->left_start ? diff_atom_root_idx(result->left, c->left_start) : -1,
498 fe621944 2020-11-10 stsp 		      c->right_start ? diff_atom_root_idx(result->right, c->right_start) : -1);
499 fe621944 2020-11-10 stsp 		assert(check_left_pos == diff_atom_root_idx(result->left, c->left_start));
500 fe621944 2020-11-10 stsp 		assert(check_right_pos == diff_atom_root_idx(result->right, c->right_start));
501 fe621944 2020-11-10 stsp 		check_left_pos += c->left_count;
502 fe621944 2020-11-10 stsp 		check_right_pos += c->right_count;
503 fe621944 2020-11-10 stsp 
504 fe621944 2020-11-10 stsp 	}
505 fe621944 2020-11-10 stsp 	assert(check_left_pos == result->left->atoms.len);
506 fe621944 2020-11-10 stsp 	assert(check_right_pos == result->right->atoms.len);
507 fe621944 2020-11-10 stsp #endif
508 fe621944 2020-11-10 stsp 
509 fe621944 2020-11-10 stsp 	for (i = 0; i < result->chunks.len; i++) {
510 fe621944 2020-11-10 stsp 		struct diff_chunk *c = &result->chunks.head[i];
511 fe621944 2020-11-10 stsp 		enum diff_chunk_type t = diff_chunk_type(c);
512 fe621944 2020-11-10 stsp 		struct diff_chunk_context next;
513 fe621944 2020-11-10 stsp 
514 fe621944 2020-11-10 stsp 		if (t != CHUNK_MINUS && t != CHUNK_PLUS)
515 fe621944 2020-11-10 stsp 			continue;
516 fe621944 2020-11-10 stsp 
517 fe621944 2020-11-10 stsp 		if (diff_chunk_context_empty(&cc)) {
518 fe621944 2020-11-10 stsp 			/* These are the first lines being printed.
519 fe621944 2020-11-10 stsp 			 * Note down the start point, any number of subsequent
520 fe621944 2020-11-10 stsp 			 * chunks may be joined up to this unidiff chunk by
521 fe621944 2020-11-10 stsp 			 * context lines or by being directly adjacent. */
522 fe621944 2020-11-10 stsp 			diff_chunk_context_get(&cc, result, i, context_lines);
523 fe621944 2020-11-10 stsp 			debug("new chunk to be printed:"
524 fe621944 2020-11-10 stsp 			      " chunk %d-%d left %d-%d right %d-%d\n",
525 fe621944 2020-11-10 stsp 			      cc.chunk.start, cc.chunk.end,
526 fe621944 2020-11-10 stsp 			      cc.left.start, cc.left.end,
527 fe621944 2020-11-10 stsp 			      cc.right.start, cc.right.end);
528 fe621944 2020-11-10 stsp 			continue;
529 fe621944 2020-11-10 stsp 		}
530 fe621944 2020-11-10 stsp 
531 fe621944 2020-11-10 stsp 		/* There already is a previous chunk noted down for being
532 fe621944 2020-11-10 stsp 		 * printed. Does it join up with this one? */
533 fe621944 2020-11-10 stsp 		diff_chunk_context_get(&next, result, i, context_lines);
534 fe621944 2020-11-10 stsp 		debug("new chunk to be printed:"
535 fe621944 2020-11-10 stsp 		      " chunk %d-%d left %d-%d right %d-%d\n",
536 fe621944 2020-11-10 stsp 		      next.chunk.start, next.chunk.end,
537 fe621944 2020-11-10 stsp 		      next.left.start, next.left.end,
538 fe621944 2020-11-10 stsp 		      next.right.start, next.right.end);
539 fe621944 2020-11-10 stsp 
540 fe621944 2020-11-10 stsp 		if (diff_chunk_contexts_touch(&cc, &next)) {
541 fe621944 2020-11-10 stsp 			/* This next context touches or overlaps the previous
542 fe621944 2020-11-10 stsp 			 * one, join. */
543 fe621944 2020-11-10 stsp 			diff_chunk_contexts_merge(&cc, &next);
544 fe621944 2020-11-10 stsp 			debug("new chunk to be printed touches previous chunk,"
545 fe621944 2020-11-10 stsp 			      " now: left %d-%d right %d-%d\n",
546 fe621944 2020-11-10 stsp 			      cc.left.start, cc.left.end,
547 fe621944 2020-11-10 stsp 			      cc.right.start, cc.right.end);
548 fe621944 2020-11-10 stsp 			continue;
549 fe621944 2020-11-10 stsp 		}
550 fe621944 2020-11-10 stsp 
551 fe621944 2020-11-10 stsp 		/* No touching, so the previous context is complete with a gap
552 fe621944 2020-11-10 stsp 		 * between it and this next one. Print the previous one and
553 fe621944 2020-11-10 stsp 		 * start fresh here. */
554 fe621944 2020-11-10 stsp 		debug("new chunk to be printed does not touch previous chunk;"
555 fe621944 2020-11-10 stsp 		      " print left %d-%d right %d-%d\n",
556 fe621944 2020-11-10 stsp 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
557 fe621944 2020-11-10 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result,
558 fe621944 2020-11-10 stsp 		    true, show_function_prototypes, &cc);
559 fe621944 2020-11-10 stsp 		cc = next;
560 fe621944 2020-11-10 stsp 		debug("new unprinted chunk is left %d-%d right %d-%d\n",
561 fe621944 2020-11-10 stsp 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
562 fe621944 2020-11-10 stsp 	}
563 fe621944 2020-11-10 stsp 
564 fe621944 2020-11-10 stsp 	if (!diff_chunk_context_empty(&cc))
565 fe621944 2020-11-10 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result,
566 fe621944 2020-11-10 stsp 		    true, show_function_prototypes, &cc);
567 fe621944 2020-11-10 stsp 	diff_output_unidiff_state_free(state);
568 fe621944 2020-11-10 stsp 	return DIFF_RC_OK;
569 fe621944 2020-11-10 stsp }