1 3b0f3d61 2020-01-22 neels /* Produce a unidiff output from a diff_result. */
  2 3b0f3d61 2020-01-22 neels /*
  3 3b0f3d61 2020-01-22 neels  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
  4 3b0f3d61 2020-01-22 neels  *
  5 3b0f3d61 2020-01-22 neels  * Permission to use, copy, modify, and distribute this software for any
  6 3b0f3d61 2020-01-22 neels  * purpose with or without fee is hereby granted, provided that the above
  7 3b0f3d61 2020-01-22 neels  * copyright notice and this permission notice appear in all copies.
  8 3b0f3d61 2020-01-22 neels  *
  9 3b0f3d61 2020-01-22 neels  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 10 3b0f3d61 2020-01-22 neels  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 11 3b0f3d61 2020-01-22 neels  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 12 3b0f3d61 2020-01-22 neels  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 13 3b0f3d61 2020-01-22 neels  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 14 3b0f3d61 2020-01-22 neels  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 15 3b0f3d61 2020-01-22 neels  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 16 3b0f3d61 2020-01-22 neels  */
 17 3b0f3d61 2020-01-22 neels 
 18 e10a628a 2020-09-16 stsp #include <errno.h>
 19 e10a628a 2020-09-16 stsp #include <inttypes.h>
 20 e10a628a 2020-09-16 stsp #include <stdbool.h>
 21 e10a628a 2020-09-16 stsp #include <stdio.h>
 22 e10a628a 2020-09-16 stsp #include <stdlib.h>
 23 e10a628a 2020-09-16 stsp 
 24 1dfba055 2020-10-07 stsp #include <arraylist.h>
 25 1dfba055 2020-10-07 stsp #include <diff_main.h>
 26 1dfba055 2020-10-07 stsp #include <diff_output.h>
 27 3b0f3d61 2020-01-22 neels 
 28 85ab4559 2020-09-22 stsp #include "diff_internal.h"
 29 2a1b94d0 2020-09-26 stsp #include "diff_debug.h"
 30 3b0f3d61 2020-01-22 neels 
 31 2f26640c 2020-10-17 stsp bool
 32 cbf93b70 2020-10-16 stsp diff_chunk_context_empty(const struct diff_chunk_context *cc)
 33 3b0f3d61 2020-01-22 neels {
 34 d362ea2e 2020-07-25 stsp 	return diff_range_empty(&cc->chunk);
 35 3b0f3d61 2020-01-22 neels }
 36 3b0f3d61 2020-01-22 neels 
 37 fe8af0d6 2020-10-06 stsp int
 38 fe8af0d6 2020-10-06 stsp diff_chunk_get_left_start(const struct diff_chunk *c,
 39 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 40 fe8af0d6 2020-10-06 stsp {
 41 fe8af0d6 2020-10-06 stsp 	int left_start = diff_atom_root_idx(&r->left, c->left_start);
 42 fe8af0d6 2020-10-06 stsp 	return MAX(0, left_start - context_lines);
 43 fe8af0d6 2020-10-06 stsp }
 44 fe8af0d6 2020-10-06 stsp 
 45 fe8af0d6 2020-10-06 stsp int
 46 fe8af0d6 2020-10-06 stsp diff_chunk_get_left_end(const struct diff_chunk *c,
 47 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 48 fe8af0d6 2020-10-06 stsp {
 49 fe8af0d6 2020-10-06 stsp 	int left_start = diff_chunk_get_left_start(c, r, 0);
 50 fe8af0d6 2020-10-06 stsp 	return MIN(r->left.atoms.len,
 51 fe8af0d6 2020-10-06 stsp 	    left_start + c->left_count + context_lines);
 52 fe8af0d6 2020-10-06 stsp }
 53 fe8af0d6 2020-10-06 stsp 
 54 fe8af0d6 2020-10-06 stsp int
 55 fe8af0d6 2020-10-06 stsp diff_chunk_get_right_start(const struct diff_chunk *c,
 56 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 57 fe8af0d6 2020-10-06 stsp {
 58 fe8af0d6 2020-10-06 stsp 	int right_start = diff_atom_root_idx(&r->right, c->right_start);
 59 fe8af0d6 2020-10-06 stsp 	return MAX(0, right_start - context_lines);
 60 fe8af0d6 2020-10-06 stsp }
 61 fe8af0d6 2020-10-06 stsp 
 62 fe8af0d6 2020-10-06 stsp int
 63 fe8af0d6 2020-10-06 stsp diff_chunk_get_right_end(const struct diff_chunk *c,
 64 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 65 fe8af0d6 2020-10-06 stsp {
 66 fe8af0d6 2020-10-06 stsp 	int right_start = diff_chunk_get_right_start(c, r, 0);
 67 fe8af0d6 2020-10-06 stsp 	return MIN(r->right.atoms.len,
 68 fe8af0d6 2020-10-06 stsp 	    right_start + c->right_count + context_lines);
 69 fe8af0d6 2020-10-06 stsp }
 70 fe8af0d6 2020-10-06 stsp 
 71 f374e913 2020-09-22 stsp void
 72 f374e913 2020-09-22 stsp diff_chunk_context_get(struct diff_chunk_context *cc, const struct diff_result *r,
 73 0d27172a 2020-05-06 neels 		  int chunk_idx, int context_lines)
 74 3b0f3d61 2020-01-22 neels {
 75 3b0f3d61 2020-01-22 neels 	const struct diff_chunk *c = &r->chunks.head[chunk_idx];
 76 fe8af0d6 2020-10-06 stsp 	int left_start = diff_chunk_get_left_start(c, r, context_lines);
 77 fe8af0d6 2020-10-06 stsp 	int left_end = diff_chunk_get_left_end(c, r, context_lines);
 78 fe8af0d6 2020-10-06 stsp 	int right_start = diff_chunk_get_right_start(c, r, context_lines);
 79 fe8af0d6 2020-10-06 stsp 	int right_end = diff_chunk_get_right_end(c, r,  context_lines);
 80 0d27172a 2020-05-06 neels 
 81 f374e913 2020-09-22 stsp 	*cc = (struct diff_chunk_context){
 82 3b0f3d61 2020-01-22 neels 		.chunk = {
 83 3b0f3d61 2020-01-22 neels 			.start = chunk_idx,
 84 3b0f3d61 2020-01-22 neels 			.end = chunk_idx + 1,
 85 3b0f3d61 2020-01-22 neels 		},
 86 3b0f3d61 2020-01-22 neels 		.left = {
 87 0d27172a 2020-05-06 neels 			.start = left_start,
 88 0d27172a 2020-05-06 neels 			.end = left_end,
 89 3b0f3d61 2020-01-22 neels 		},
 90 3b0f3d61 2020-01-22 neels 		.right = {
 91 0d27172a 2020-05-06 neels 			.start = right_start,
 92 0d27172a 2020-05-06 neels 			.end = right_end,
 93 3b0f3d61 2020-01-22 neels 		},
 94 3b0f3d61 2020-01-22 neels 	};
 95 3b0f3d61 2020-01-22 neels }
 96 3b0f3d61 2020-01-22 neels 
 97 2f26640c 2020-10-17 stsp bool
 98 26595c7d 2020-10-15 stsp diff_chunk_contexts_touch(const struct diff_chunk_context *cc,
 99 26595c7d 2020-10-15 stsp 			  const struct diff_chunk_context *other)
100 3b0f3d61 2020-01-22 neels {
101 d362ea2e 2020-07-25 stsp 	return diff_ranges_touch(&cc->chunk, &other->chunk)
102 d362ea2e 2020-07-25 stsp 		|| diff_ranges_touch(&cc->left, &other->left)
103 d362ea2e 2020-07-25 stsp 		|| diff_ranges_touch(&cc->right, &other->right);
104 3b0f3d61 2020-01-22 neels }
105 3b0f3d61 2020-01-22 neels 
106 26595c7d 2020-10-15 stsp void
107 26595c7d 2020-10-15 stsp diff_chunk_contexts_merge(struct diff_chunk_context *cc,
108 26595c7d 2020-10-15 stsp 			  const struct diff_chunk_context *other)
109 3b0f3d61 2020-01-22 neels {
110 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->chunk, &other->chunk);
111 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->left, &other->left);
112 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->right, &other->right);
113 7187fe97 2020-10-17 stsp }
114 7187fe97 2020-10-17 stsp 
115 7187fe97 2020-10-17 stsp void
116 7187fe97 2020-10-17 stsp diff_chunk_context_load_change(struct diff_chunk_context *cc,
117 7187fe97 2020-10-17 stsp 			       int *nchunks_used,
118 7187fe97 2020-10-17 stsp 			       struct diff_result *result,
119 7187fe97 2020-10-17 stsp 			       int start_chunk_idx,
120 7187fe97 2020-10-17 stsp 			       int context_lines)
121 7187fe97 2020-10-17 stsp {
122 7187fe97 2020-10-17 stsp 	int i;
123 7187fe97 2020-10-17 stsp 	int seen_minus = 0, seen_plus = 0;
124 7187fe97 2020-10-17 stsp 
125 7187fe97 2020-10-17 stsp 	if (nchunks_used)
126 7187fe97 2020-10-17 stsp 		*nchunks_used = 0;
127 7187fe97 2020-10-17 stsp 
128 7187fe97 2020-10-17 stsp 	for (i = start_chunk_idx; i < result->chunks.len; i++) {
129 7187fe97 2020-10-17 stsp 		struct diff_chunk *chunk = &result->chunks.head[i];
130 7187fe97 2020-10-17 stsp 		enum diff_chunk_type t = diff_chunk_type(chunk);
131 7187fe97 2020-10-17 stsp 		struct diff_chunk_context next;
132 7187fe97 2020-10-17 stsp 
133 7187fe97 2020-10-17 stsp 		if (t != CHUNK_MINUS && t != CHUNK_PLUS) {
134 7187fe97 2020-10-17 stsp 			if (nchunks_used)
135 7187fe97 2020-10-17 stsp 				(*nchunks_used)++;
136 f4867452 2020-10-17 stsp 			if (seen_minus || seen_plus)
137 7187fe97 2020-10-17 stsp 				break;
138 7187fe97 2020-10-17 stsp 			else
139 7187fe97 2020-10-17 stsp 				continue;
140 7187fe97 2020-10-17 stsp 		} else if (t == CHUNK_MINUS)
141 7187fe97 2020-10-17 stsp 			seen_minus = 1;
142 7187fe97 2020-10-17 stsp 		else if (t == CHUNK_PLUS)
143 7187fe97 2020-10-17 stsp 			seen_plus = 1;
144 7187fe97 2020-10-17 stsp 
145 7187fe97 2020-10-17 stsp 		if (diff_chunk_context_empty(cc)) {
146 7187fe97 2020-10-17 stsp 			/* Note down the start point, any number of subsequent
147 7187fe97 2020-10-17 stsp 			 * chunks may be joined up to this chunk by being
148 7187fe97 2020-10-17 stsp 			 * directly adjacent. */
149 7187fe97 2020-10-17 stsp 			diff_chunk_context_get(cc, result, i, context_lines);
150 7187fe97 2020-10-17 stsp 			if (nchunks_used)
151 7187fe97 2020-10-17 stsp 				(*nchunks_used)++;
152 7187fe97 2020-10-17 stsp 			continue;
153 7187fe97 2020-10-17 stsp 		}
154 7187fe97 2020-10-17 stsp 
155 7187fe97 2020-10-17 stsp 		/* There already is a previous chunk noted down for being
156 7187fe97 2020-10-17 stsp 		 * printed. Does it join up with this one? */
157 7187fe97 2020-10-17 stsp 		diff_chunk_context_get(&next, result, i, context_lines);
158 7187fe97 2020-10-17 stsp 
159 7187fe97 2020-10-17 stsp 		if (diff_chunk_contexts_touch(cc, &next)) {
160 7187fe97 2020-10-17 stsp 			/* This next context touches or overlaps the previous
161 7187fe97 2020-10-17 stsp 			 * one, join. */
162 7187fe97 2020-10-17 stsp 			diff_chunk_contexts_merge(cc, &next);
163 7187fe97 2020-10-17 stsp 			if (nchunks_used)
164 7187fe97 2020-10-17 stsp 				(*nchunks_used)++;
165 7187fe97 2020-10-17 stsp 			continue;
166 7187fe97 2020-10-17 stsp 		} else
167 7187fe97 2020-10-17 stsp 			break;
168 7187fe97 2020-10-17 stsp 	}
169 3b0f3d61 2020-01-22 neels }
170 3b0f3d61 2020-01-22 neels 
171 11caa5cc 2020-09-22 stsp struct diff_output_unidiff_state {
172 11caa5cc 2020-09-22 stsp 	bool header_printed;
173 11caa5cc 2020-09-22 stsp };
174 11caa5cc 2020-09-22 stsp 
175 11caa5cc 2020-09-22 stsp struct diff_output_unidiff_state *
176 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_alloc(void)
177 11caa5cc 2020-09-22 stsp {
178 11caa5cc 2020-09-22 stsp 	struct diff_output_unidiff_state *state;
179 11caa5cc 2020-09-22 stsp 
180 11caa5cc 2020-09-22 stsp 	state = calloc(1, sizeof(struct diff_output_unidiff_state));
181 11caa5cc 2020-09-22 stsp 	if (state != NULL)
182 11caa5cc 2020-09-22 stsp 		diff_output_unidiff_state_reset(state);
183 11caa5cc 2020-09-22 stsp 	return state;
184 11caa5cc 2020-09-22 stsp }
185 11caa5cc 2020-09-22 stsp 
186 f374e913 2020-09-22 stsp void
187 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_reset(struct diff_output_unidiff_state *state)
188 11caa5cc 2020-09-22 stsp {
189 11caa5cc 2020-09-22 stsp 	state->header_printed = false;
190 11caa5cc 2020-09-22 stsp }
191 11caa5cc 2020-09-22 stsp 
192 11caa5cc 2020-09-22 stsp void
193 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_free(struct diff_output_unidiff_state *state)
194 11caa5cc 2020-09-22 stsp {
195 11caa5cc 2020-09-22 stsp 	free(state);
196 11caa5cc 2020-09-22 stsp }
197 11caa5cc 2020-09-22 stsp 
198 2c20a3ed 2020-09-22 stsp static int
199 2c20a3ed 2020-09-22 stsp output_unidiff_chunk(struct diff_output_info *outinfo, FILE *dest,
200 2c20a3ed 2020-09-22 stsp 		     struct diff_output_unidiff_state *state,
201 2c20a3ed 2020-09-22 stsp 		     const struct diff_input_info *info,
202 2c20a3ed 2020-09-22 stsp 		     const struct diff_result *result,
203 13e2caa3 2020-10-17 stsp 		     bool print_header, bool show_function_prototypes,
204 2c20a3ed 2020-09-22 stsp 		     const struct diff_chunk_context *cc)
205 3b0f3d61 2020-01-22 neels {
206 b6adedb6 2020-10-07 stsp 	int rc, left_start, left_len, right_start, right_len;
207 ab528e22 2020-09-22 stsp 	off_t outoff = 0, *offp;
208 13e2caa3 2020-10-17 stsp 	char *prototype = NULL;
209 2c20a3ed 2020-09-22 stsp 
210 d362ea2e 2020-07-25 stsp 	if (diff_range_empty(&cc->left) && diff_range_empty(&cc->right))
211 2c20a3ed 2020-09-22 stsp 		return DIFF_RC_OK;
212 3b0f3d61 2020-01-22 neels 
213 2c20a3ed 2020-09-22 stsp 	if (outinfo && outinfo->line_offsets.len > 0) {
214 2c20a3ed 2020-09-22 stsp 		unsigned int idx = outinfo->line_offsets.len - 1;
215 2c20a3ed 2020-09-22 stsp 		outoff = outinfo->line_offsets.head[idx];
216 2c20a3ed 2020-09-22 stsp 	}
217 2c20a3ed 2020-09-22 stsp 
218 66ea8e5a 2020-10-17 stsp 	if (print_header && !(state->header_printed)) {
219 2c20a3ed 2020-09-22 stsp 		rc = fprintf(dest, "--- %s\n", info->left_path ? : "a");
220 2c20a3ed 2020-09-22 stsp 		if (rc < 0)
221 2c20a3ed 2020-09-22 stsp 			return errno;
222 2c20a3ed 2020-09-22 stsp 		if (outinfo) {
223 2c20a3ed 2020-09-22 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
224 dabc1008 2020-09-22 stsp 			if (offp == NULL)
225 dabc1008 2020-09-22 stsp 				return ENOMEM;
226 2c20a3ed 2020-09-22 stsp 			outoff += rc;
227 2c20a3ed 2020-09-22 stsp 			*offp = outoff;
228 2c20a3ed 2020-09-22 stsp 
229 2c20a3ed 2020-09-22 stsp 		}
230 2c20a3ed 2020-09-22 stsp 		rc = fprintf(dest, "+++ %s\n", info->right_path ? : "b");
231 2c20a3ed 2020-09-22 stsp 		if (rc < 0)
232 2c20a3ed 2020-09-22 stsp 			return errno;
233 2c20a3ed 2020-09-22 stsp 		if (outinfo) {
234 2c20a3ed 2020-09-22 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
235 dabc1008 2020-09-22 stsp 			if (offp == NULL)
236 dabc1008 2020-09-22 stsp 				return ENOMEM;
237 2c20a3ed 2020-09-22 stsp 			outoff += rc;
238 2c20a3ed 2020-09-22 stsp 			*offp = outoff;
239 2c20a3ed 2020-09-22 stsp 
240 2c20a3ed 2020-09-22 stsp 		}
241 11caa5cc 2020-09-22 stsp 		state->header_printed = true;
242 3b0f3d61 2020-01-22 neels 	}
243 3b0f3d61 2020-01-22 neels 
244 b6adedb6 2020-10-07 stsp 	left_len = cc->left.end - cc->left.start;
245 11d9f2f7 2020-10-07 stsp 	if (result->left.atoms.len == 0)
246 11d9f2f7 2020-10-07 stsp 		left_start = 0;
247 11d9f2f7 2020-10-07 stsp 	else if (left_len == 0 && cc->left.start > 0)
248 b6adedb6 2020-10-07 stsp 		left_start = cc->left.start;
249 b6adedb6 2020-10-07 stsp 	else
250 b6adedb6 2020-10-07 stsp 		left_start = cc->left.start + 1;
251 b6adedb6 2020-10-07 stsp 
252 b6adedb6 2020-10-07 stsp 	right_len = cc->right.end - cc->right.start;
253 11d9f2f7 2020-10-07 stsp 	if (result->right.atoms.len == 0)
254 11d9f2f7 2020-10-07 stsp 		right_start = 0;
255 11d9f2f7 2020-10-07 stsp 	else if (right_len == 0 && cc->right.start > 0)
256 b6adedb6 2020-10-07 stsp 		right_start = cc->right.start;
257 b6adedb6 2020-10-07 stsp 	else
258 b6adedb6 2020-10-07 stsp 		right_start = cc->right.start + 1;
259 13e2caa3 2020-10-17 stsp 
260 13e2caa3 2020-10-17 stsp 	if (show_function_prototypes) {
261 13e2caa3 2020-10-17 stsp 		rc = diff_output_match_function_prototype(&prototype,
262 13e2caa3 2020-10-17 stsp 		    result, cc);
263 13e2caa3 2020-10-17 stsp 		if (rc)
264 13e2caa3 2020-10-17 stsp 			return rc;
265 13e2caa3 2020-10-17 stsp 	}
266 b6adedb6 2020-10-07 stsp 
267 d2dfa2ec 2020-10-07 stsp 	if (left_len == 1 && right_len == 1) {
268 13e2caa3 2020-10-17 stsp 		rc = fprintf(dest, "@@ -%d +%d @@%s%s\n",
269 13e2caa3 2020-10-17 stsp 			left_start, right_start,
270 13e2caa3 2020-10-17 stsp 			prototype ? " " : "",
271 13e2caa3 2020-10-17 stsp 			prototype ? : "");
272 d2dfa2ec 2020-10-07 stsp 	} else if (left_len == 1 && right_len != 1) {
273 13e2caa3 2020-10-17 stsp 		rc = fprintf(dest, "@@ -%d +%d,%d @@%s%s\n",
274 13e2caa3 2020-10-17 stsp 			left_start, right_start, right_len,
275 13e2caa3 2020-10-17 stsp 			prototype ? " " : "",
276 13e2caa3 2020-10-17 stsp 			prototype ? : "");
277 b6adedb6 2020-10-07 stsp 	} else if (left_len != 1 && right_len == 1) {
278 13e2caa3 2020-10-17 stsp 		rc = fprintf(dest, "@@ -%d,%d +%d @@%s%s\n",
279 13e2caa3 2020-10-17 stsp 			left_start, left_len, right_start,
280 13e2caa3 2020-10-17 stsp 			prototype ? " " : "",
281 13e2caa3 2020-10-17 stsp 			prototype ? : "");
282 b6adedb6 2020-10-07 stsp 	} else {
283 13e2caa3 2020-10-17 stsp 		rc = fprintf(dest, "@@ -%d,%d +%d,%d @@%s%s\n",
284 13e2caa3 2020-10-17 stsp 			left_start, left_len, right_start, right_len,
285 13e2caa3 2020-10-17 stsp 			prototype ? " " : "",
286 13e2caa3 2020-10-17 stsp 			prototype ? : "");
287 b6adedb6 2020-10-07 stsp 	}
288 13e2caa3 2020-10-17 stsp 	free(prototype);
289 2c20a3ed 2020-09-22 stsp 	if (rc < 0)
290 2c20a3ed 2020-09-22 stsp 		return errno;
291 2c20a3ed 2020-09-22 stsp 	if (outinfo) {
292 2c20a3ed 2020-09-22 stsp 		ARRAYLIST_ADD(offp, outinfo->line_offsets);
293 dabc1008 2020-09-22 stsp 		if (offp == NULL)
294 dabc1008 2020-09-22 stsp 			return ENOMEM;
295 2c20a3ed 2020-09-22 stsp 		outoff += rc;
296 2c20a3ed 2020-09-22 stsp 		*offp = outoff;
297 3b0f3d61 2020-01-22 neels 
298 2c20a3ed 2020-09-22 stsp 	}
299 2c20a3ed 2020-09-22 stsp 
300 0d27172a 2020-05-06 neels 	/* Got the absolute line numbers where to start printing, and the index
301 0d27172a 2020-05-06 neels 	 * of the interesting (non-context) chunk.
302 0d27172a 2020-05-06 neels 	 * To print context lines above the interesting chunk, nipping on the
303 0d27172a 2020-05-06 neels 	 * previous chunk index may be necessary.
304 0d27172a 2020-05-06 neels 	 * It is guaranteed to be only context lines where left == right, so it
305 0d27172a 2020-05-06 neels 	 * suffices to look on the left. */
306 0d27172a 2020-05-06 neels 	const struct diff_chunk *first_chunk;
307 0d27172a 2020-05-06 neels 	int chunk_start_line;
308 0d27172a 2020-05-06 neels 	first_chunk = &result->chunks.head[cc->chunk.start];
309 0d27172a 2020-05-06 neels 	chunk_start_line = diff_atom_root_idx(&result->left,
310 0d27172a 2020-05-06 neels 					      first_chunk->left_start);
311 2c20a3ed 2020-09-22 stsp 	if (cc->left.start < chunk_start_line) {
312 2c20a3ed 2020-09-22 stsp 		rc = diff_output_lines(outinfo, dest, " ",
313 0d27172a 2020-05-06 neels 				  &result->left.atoms.head[cc->left.start],
314 3b0f3d61 2020-01-22 neels 				  chunk_start_line - cc->left.start);
315 2c20a3ed 2020-09-22 stsp 		if (rc)
316 2c20a3ed 2020-09-22 stsp 			return rc;
317 2c20a3ed 2020-09-22 stsp 	}
318 3b0f3d61 2020-01-22 neels 
319 3b0f3d61 2020-01-22 neels 	/* Now write out all the joined chunks and contexts between them */
320 3b0f3d61 2020-01-22 neels 	int c_idx;
321 3b0f3d61 2020-01-22 neels 	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
322 3b0f3d61 2020-01-22 neels 		const struct diff_chunk *c = &result->chunks.head[c_idx];
323 3b0f3d61 2020-01-22 neels 
324 3b0f3d61 2020-01-22 neels 		if (c->left_count && c->right_count)
325 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
326 0d27172a 2020-05-06 neels 					  c->solved ? " " : "?",
327 0d27172a 2020-05-06 neels 					  c->left_start, c->left_count);
328 3b0f3d61 2020-01-22 neels 		else if (c->left_count && !c->right_count)
329 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
330 0d27172a 2020-05-06 neels 					  c->solved ? "-" : "?",
331 0d27172a 2020-05-06 neels 					  c->left_start, c->left_count);
332 3b0f3d61 2020-01-22 neels 		else if (c->right_count && !c->left_count)
333 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
334 0d27172a 2020-05-06 neels 					  c->solved ? "+" : "?",
335 0d27172a 2020-05-06 neels 					  c->right_start, c->right_count);
336 2c20a3ed 2020-09-22 stsp 		if (rc)
337 2c20a3ed 2020-09-22 stsp 			return rc;
338 7021523c 2020-10-16 stsp 
339 7021523c 2020-10-16 stsp 		if (cc->chunk.end == result->chunks.len) {
340 7021523c 2020-10-16 stsp 			rc = diff_output_trailing_newline_msg(outinfo, dest, c);
341 7021523c 2020-10-16 stsp 			if (rc != DIFF_RC_OK)
342 7021523c 2020-10-16 stsp 				return rc;
343 7021523c 2020-10-16 stsp 		}
344 3b0f3d61 2020-01-22 neels 	}
345 3b0f3d61 2020-01-22 neels 
346 3b0f3d61 2020-01-22 neels 	/* Trailing context? */
347 0d27172a 2020-05-06 neels 	const struct diff_chunk *last_chunk;
348 0d27172a 2020-05-06 neels 	int chunk_end_line;
349 0d27172a 2020-05-06 neels 	last_chunk = &result->chunks.head[cc->chunk.end - 1];
350 0d27172a 2020-05-06 neels 	chunk_end_line = diff_atom_root_idx(&result->left,
351 0d27172a 2020-05-06 neels 					    last_chunk->left_start
352 0d27172a 2020-05-06 neels 					    + last_chunk->left_count);
353 2c20a3ed 2020-09-22 stsp 	if (cc->left.end > chunk_end_line) {
354 2c20a3ed 2020-09-22 stsp 		rc = diff_output_lines(outinfo, dest, " ",
355 0d27172a 2020-05-06 neels 				  &result->left.atoms.head[chunk_end_line],
356 3b0f3d61 2020-01-22 neels 				  cc->left.end - chunk_end_line);
357 2c20a3ed 2020-09-22 stsp 		if (rc)
358 2c20a3ed 2020-09-22 stsp 			return rc;
359 2c20a3ed 2020-09-22 stsp 	}
360 2c20a3ed 2020-09-22 stsp 
361 2c20a3ed 2020-09-22 stsp 	return DIFF_RC_OK;
362 3b0f3d61 2020-01-22 neels }
363 3b0f3d61 2020-01-22 neels 
364 3e6cba3a 2020-08-13 stsp int
365 2c20a3ed 2020-09-22 stsp diff_output_unidiff_chunk(struct diff_output_info **output_info, FILE *dest,
366 2c20a3ed 2020-09-22 stsp 			  struct diff_output_unidiff_state *state,
367 2c20a3ed 2020-09-22 stsp 			  const struct diff_input_info *info,
368 2c20a3ed 2020-09-22 stsp 			  const struct diff_result *result,
369 2c20a3ed 2020-09-22 stsp 			  const struct diff_chunk_context *cc)
370 2c20a3ed 2020-09-22 stsp {
371 2c20a3ed 2020-09-22 stsp 	struct diff_output_info *outinfo = NULL;
372 13e2caa3 2020-10-17 stsp 	int flags = (result->left.root->diff_flags |
373 13e2caa3 2020-10-17 stsp 	    result->right.root->diff_flags);
374 13e2caa3 2020-10-17 stsp 	bool show_function_prototypes = (flags & DIFF_FLAG_SHOW_PROTOTYPES);
375 2c20a3ed 2020-09-22 stsp 
376 2c20a3ed 2020-09-22 stsp 	if (output_info) {
377 2c20a3ed 2020-09-22 stsp 		*output_info = diff_output_info_alloc();
378 2c20a3ed 2020-09-22 stsp 		if (*output_info == NULL)
379 2c20a3ed 2020-09-22 stsp 			return ENOMEM;
380 2c20a3ed 2020-09-22 stsp 		outinfo = *output_info;
381 2c20a3ed 2020-09-22 stsp 	}
382 2c20a3ed 2020-09-22 stsp 
383 2c20a3ed 2020-09-22 stsp 	return output_unidiff_chunk(outinfo, dest, state, info,
384 13e2caa3 2020-10-17 stsp 	    result, false, show_function_prototypes, cc);
385 2c20a3ed 2020-09-22 stsp }
386 2c20a3ed 2020-09-22 stsp 
387 2c20a3ed 2020-09-22 stsp int
388 2c20a3ed 2020-09-22 stsp diff_output_unidiff(struct diff_output_info **output_info,
389 2c20a3ed 2020-09-22 stsp 		    FILE *dest, const struct diff_input_info *info,
390 0d27172a 2020-05-06 neels 		    const struct diff_result *result,
391 0d27172a 2020-05-06 neels 		    unsigned int context_lines)
392 3b0f3d61 2020-01-22 neels {
393 11caa5cc 2020-09-22 stsp 	struct diff_output_unidiff_state *state;
394 11caa5cc 2020-09-22 stsp 	struct diff_chunk_context cc = {};
395 2c20a3ed 2020-09-22 stsp 	struct diff_output_info *outinfo = NULL;
396 13e2caa3 2020-10-17 stsp 	int flags = (result->left.root->diff_flags |
397 13e2caa3 2020-10-17 stsp 	    result->right.root->diff_flags);
398 13e2caa3 2020-10-17 stsp 	bool show_function_prototypes = (flags & DIFF_FLAG_SHOW_PROTOTYPES);
399 11caa5cc 2020-09-22 stsp 	int i;
400 11caa5cc 2020-09-22 stsp 
401 3b0f3d61 2020-01-22 neels 	if (!result)
402 3e6cba3a 2020-08-13 stsp 		return EINVAL;
403 3b0f3d61 2020-01-22 neels 	if (result->rc != DIFF_RC_OK)
404 3b0f3d61 2020-01-22 neels 		return result->rc;
405 3b0f3d61 2020-01-22 neels 
406 2c20a3ed 2020-09-22 stsp 	if (output_info) {
407 2c20a3ed 2020-09-22 stsp 		*output_info = diff_output_info_alloc();
408 2c20a3ed 2020-09-22 stsp 		if (*output_info == NULL)
409 2c20a3ed 2020-09-22 stsp 			return ENOMEM;
410 2c20a3ed 2020-09-22 stsp 		outinfo = *output_info;
411 2c20a3ed 2020-09-22 stsp 	}
412 2c20a3ed 2020-09-22 stsp 
413 11caa5cc 2020-09-22 stsp 	state = diff_output_unidiff_state_alloc();
414 2c20a3ed 2020-09-22 stsp 	if (state == NULL) {
415 2c20a3ed 2020-09-22 stsp 		if (output_info) {
416 2c20a3ed 2020-09-22 stsp 			diff_output_info_free(*output_info);
417 2c20a3ed 2020-09-22 stsp 			*output_info = NULL;
418 2c20a3ed 2020-09-22 stsp 		}
419 11caa5cc 2020-09-22 stsp 		return ENOMEM;
420 2c20a3ed 2020-09-22 stsp 	}
421 3b0f3d61 2020-01-22 neels 
422 5ff75996 2020-10-11 neels #if DEBUG
423 5ff75996 2020-10-11 neels 	for (i = 0; i < result->chunks.len; i++) {
424 5ff75996 2020-10-11 neels 		struct diff_chunk *c = &result->chunks.head[i];
425 5ff75996 2020-10-11 neels 		enum diff_chunk_type t = diff_chunk_type(c);
426 2c20a3ed 2020-09-22 stsp 
427 5ff75996 2020-10-11 neels 		debug("[%d] %s lines L%d R%d @L %d @R %d\n",
428 5ff75996 2020-10-11 neels 		      i, (t == CHUNK_MINUS ? "minus" :
429 5ff75996 2020-10-11 neels 			  (t == CHUNK_PLUS ? "plus" :
430 5ff75996 2020-10-11 neels 			   (t == CHUNK_SAME ? "same" : "?"))),
431 5ff75996 2020-10-11 neels 		      c->left_count,
432 5ff75996 2020-10-11 neels 		      c->right_count,
433 5ff75996 2020-10-11 neels 		      c->left_start ? diff_atom_root_idx(&result->left, c->left_start) : -1,
434 5ff75996 2020-10-11 neels 		      c->right_start ? diff_atom_root_idx(&result->right, c->right_start) : -1);
435 5ff75996 2020-10-11 neels 	}
436 5ff75996 2020-10-11 neels #endif
437 5ff75996 2020-10-11 neels 
438 3b0f3d61 2020-01-22 neels 	for (i = 0; i < result->chunks.len; i++) {
439 3b0f3d61 2020-01-22 neels 		struct diff_chunk *c = &result->chunks.head[i];
440 8546b045 2020-09-20 neels 		enum diff_chunk_type t = diff_chunk_type(c);
441 f374e913 2020-09-22 stsp 		struct diff_chunk_context next;
442 3b0f3d61 2020-01-22 neels 
443 9cc49695 2020-05-05 neels 		if (t != CHUNK_MINUS && t != CHUNK_PLUS)
444 9cc49695 2020-05-05 neels 			continue;
445 9cc49695 2020-05-05 neels 
446 cbf93b70 2020-10-16 stsp 		if (diff_chunk_context_empty(&cc)) {
447 9cc49695 2020-05-05 neels 			/* These are the first lines being printed.
448 0d27172a 2020-05-06 neels 			 * Note down the start point, any number of subsequent
449 0d27172a 2020-05-06 neels 			 * chunks may be joined up to this unidiff chunk by
450 0d27172a 2020-05-06 neels 			 * context lines or by being directly adjacent. */
451 f374e913 2020-09-22 stsp 			diff_chunk_context_get(&cc, result, i, context_lines);
452 0d27172a 2020-05-06 neels 			debug("new chunk to be printed:"
453 0d27172a 2020-05-06 neels 			      " chunk %d-%d left %d-%d right %d-%d\n",
454 9cc49695 2020-05-05 neels 			      cc.chunk.start, cc.chunk.end,
455 9cc49695 2020-05-05 neels 			      cc.left.start, cc.left.end,
456 9cc49695 2020-05-05 neels 			      cc.right.start, cc.right.end);
457 9cc49695 2020-05-05 neels 			continue;
458 3b0f3d61 2020-01-22 neels 		}
459 3b0f3d61 2020-01-22 neels 
460 0d27172a 2020-05-06 neels 		/* There already is a previous chunk noted down for being
461 0d27172a 2020-05-06 neels 		 * printed. Does it join up with this one? */
462 f374e913 2020-09-22 stsp 		diff_chunk_context_get(&next, result, i, context_lines);
463 0d27172a 2020-05-06 neels 		debug("new chunk to be printed:"
464 0d27172a 2020-05-06 neels 		      " chunk %d-%d left %d-%d right %d-%d\n",
465 9cc49695 2020-05-05 neels 		      next.chunk.start, next.chunk.end,
466 9cc49695 2020-05-05 neels 		      next.left.start, next.left.end,
467 9cc49695 2020-05-05 neels 		      next.right.start, next.right.end);
468 9cc49695 2020-05-05 neels 
469 26595c7d 2020-10-15 stsp 		if (diff_chunk_contexts_touch(&cc, &next)) {
470 0d27172a 2020-05-06 neels 			/* This next context touches or overlaps the previous
471 0d27172a 2020-05-06 neels 			 * one, join. */
472 26595c7d 2020-10-15 stsp 			diff_chunk_contexts_merge(&cc, &next);
473 0d27172a 2020-05-06 neels 			debug("new chunk to be printed touches previous chunk,"
474 0d27172a 2020-05-06 neels 			      " now: left %d-%d right %d-%d\n",
475 9cc49695 2020-05-05 neels 			      cc.left.start, cc.left.end,
476 9cc49695 2020-05-05 neels 			      cc.right.start, cc.right.end);
477 9cc49695 2020-05-05 neels 			continue;
478 9cc49695 2020-05-05 neels 		}
479 9cc49695 2020-05-05 neels 
480 0d27172a 2020-05-06 neels 		/* No touching, so the previous context is complete with a gap
481 0d27172a 2020-05-06 neels 		 * between it and this next one. Print the previous one and
482 0d27172a 2020-05-06 neels 		 * start fresh here. */
483 0d27172a 2020-05-06 neels 		debug("new chunk to be printed does not touch previous chunk;"
484 0d27172a 2020-05-06 neels 		      " print left %d-%d right %d-%d\n",
485 9cc49695 2020-05-05 neels 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
486 66ea8e5a 2020-10-17 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result,
487 13e2caa3 2020-10-17 stsp 		    true, show_function_prototypes, &cc);
488 9cc49695 2020-05-05 neels 		cc = next;
489 9cc49695 2020-05-05 neels 		debug("new unprinted chunk is left %d-%d right %d-%d\n",
490 9cc49695 2020-05-05 neels 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
491 3b0f3d61 2020-01-22 neels 	}
492 3b0f3d61 2020-01-22 neels 
493 cbf93b70 2020-10-16 stsp 	if (!diff_chunk_context_empty(&cc))
494 66ea8e5a 2020-10-17 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result,
495 13e2caa3 2020-10-17 stsp 		    true, show_function_prototypes, &cc);
496 11caa5cc 2020-09-22 stsp 	diff_output_unidiff_state_free(state);
497 3b0f3d61 2020-01-22 neels 	return DIFF_RC_OK;
498 3b0f3d61 2020-01-22 neels }