1 fe621944 2020-11-10 stsp /* Output all lines of 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 f3c44083 2020-11-14 naddy #include <stdint.h>
 20 fe621944 2020-11-10 stsp #include <stdio.h>
 21 fe621944 2020-11-10 stsp #include <stdbool.h>
 22 fe621944 2020-11-10 stsp #include <stdlib.h>
 23 fe621944 2020-11-10 stsp 
 24 fe621944 2020-11-10 stsp #include <arraylist.h>
 25 fe621944 2020-11-10 stsp #include <diff_main.h>
 26 fe621944 2020-11-10 stsp #include <diff_output.h>
 27 fe621944 2020-11-10 stsp 
 28 fe621944 2020-11-10 stsp #include "diff_internal.h"
 29 fe621944 2020-11-10 stsp 
 30 f068d119 2022-09-02 stsp static int
 31 f068d119 2022-09-02 stsp output_plain_chunk(struct diff_output_info *outinfo,
 32 f068d119 2022-09-02 stsp     FILE *dest, const struct diff_input_info *info,
 33 f068d119 2022-09-02 stsp     const struct diff_result *result,
 34 f068d119 2022-09-02 stsp     struct diff_chunk_context *cc)
 35 f068d119 2022-09-02 stsp {
 36 f068d119 2022-09-02 stsp 	off_t outoff = 0, *offp;
 37 f068d119 2022-09-02 stsp 	int left_start, left_len, right_start, right_len;
 38 f068d119 2022-09-02 stsp 	int rc;
 39 f068d119 2022-09-02 stsp 	bool change = false;
 40 f068d119 2022-09-02 stsp 
 41 f068d119 2022-09-02 stsp 	left_len = cc->left.end - cc->left.start;
 42 f068d119 2022-09-02 stsp 	if (left_len < 0)
 43 f068d119 2022-09-02 stsp 		return EINVAL;
 44 f068d119 2022-09-02 stsp 	else if (result->left->atoms.len == 0)
 45 f068d119 2022-09-02 stsp 		left_start = 0;
 46 f068d119 2022-09-02 stsp 	else if (left_len == 0 && cc->left.start > 0)
 47 f068d119 2022-09-02 stsp 		left_start = cc->left.start;
 48 f068d119 2022-09-02 stsp 	else if (cc->left.end > 0)
 49 f068d119 2022-09-02 stsp 		left_start = cc->left.start + 1;
 50 f068d119 2022-09-02 stsp 	else
 51 f068d119 2022-09-02 stsp 		left_start = cc->left.start;
 52 f068d119 2022-09-02 stsp 
 53 f068d119 2022-09-02 stsp 	right_len = cc->right.end - cc->right.start;
 54 f068d119 2022-09-02 stsp 	if (right_len < 0)
 55 f068d119 2022-09-02 stsp 		return EINVAL;
 56 f068d119 2022-09-02 stsp 	else if (result->right->atoms.len == 0)
 57 f068d119 2022-09-02 stsp 		right_start = 0;
 58 f068d119 2022-09-02 stsp 	else if (right_len == 0 && cc->right.start > 0)
 59 f068d119 2022-09-02 stsp 		right_start = cc->right.start;
 60 f068d119 2022-09-02 stsp 	else if (cc->right.end > 0)
 61 f068d119 2022-09-02 stsp 		right_start = cc->right.start + 1;
 62 f068d119 2022-09-02 stsp 	else
 63 f068d119 2022-09-02 stsp 		right_start = cc->right.start;
 64 f068d119 2022-09-02 stsp 
 65 f068d119 2022-09-02 stsp 	if (left_len == 0) {
 66 f068d119 2022-09-02 stsp 		/* addition */
 67 f068d119 2022-09-02 stsp 		if (right_len == 1) {
 68 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%da%d\n", left_start, right_start);
 69 f068d119 2022-09-02 stsp 		} else {
 70 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%da%d,%d\n", left_start,
 71 f068d119 2022-09-02 stsp 			    right_start, cc->right.end);
 72 f068d119 2022-09-02 stsp 		}
 73 f068d119 2022-09-02 stsp 	} else if (right_len == 0) {
 74 f068d119 2022-09-02 stsp 		/* deletion */
 75 f068d119 2022-09-02 stsp 		if (left_len == 1) {
 76 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%dd%d\n", left_start,
 77 f068d119 2022-09-02 stsp 			    right_start);
 78 f068d119 2022-09-02 stsp 		} else {
 79 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%d,%dd%d\n", left_start,
 80 f068d119 2022-09-02 stsp 			    cc->left.end, right_start);
 81 f068d119 2022-09-02 stsp 		}
 82 f068d119 2022-09-02 stsp 	} else {
 83 f068d119 2022-09-02 stsp 		/* change */
 84 f068d119 2022-09-02 stsp 		change = true;
 85 f068d119 2022-09-02 stsp 		if (left_len == 1 && right_len == 1) {
 86 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%dc%d\n", left_start, right_start);
 87 f068d119 2022-09-02 stsp 		} else if (left_len == 1) {
 88 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%dc%d,%d\n", left_start,
 89 f068d119 2022-09-02 stsp 			    right_start, cc->right.end);
 90 f068d119 2022-09-02 stsp 		} else if (right_len == 1) {
 91 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%d,%dc%d\n", left_start,
 92 f068d119 2022-09-02 stsp 			    cc->left.end, right_start);
 93 f068d119 2022-09-02 stsp 		} else {
 94 f068d119 2022-09-02 stsp 			rc = fprintf(dest, "%d,%dc%d,%d\n", left_start,
 95 f068d119 2022-09-02 stsp 			    cc->left.end, right_start, cc->right.end);
 96 f068d119 2022-09-02 stsp 		}
 97 f068d119 2022-09-02 stsp 	}
 98 f068d119 2022-09-02 stsp 
 99 f068d119 2022-09-02 stsp 	/*
100 f068d119 2022-09-02 stsp 	 * Now write out all the joined chunks.
101 f068d119 2022-09-02 stsp 	 *
102 f068d119 2022-09-02 stsp 	 * If the hunk denotes a change, it will come in the form of a deletion
103 f068d119 2022-09-02 stsp 	 * chunk followed by a addition chunk. Print a marker to break up the
104 f068d119 2022-09-02 stsp 	 * additions and deletions when this happens.
105 f068d119 2022-09-02 stsp 	 */
106 f068d119 2022-09-02 stsp 	int c_idx;
107 f068d119 2022-09-02 stsp 	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
108 f068d119 2022-09-02 stsp 		const struct diff_chunk *c = &result->chunks.head[c_idx];
109 f068d119 2022-09-02 stsp 		if (c->left_count && !c->right_count)
110 f068d119 2022-09-02 stsp 			rc = diff_output_lines(outinfo, dest,
111 f068d119 2022-09-02 stsp 					  c->solved ? "< " : "?",
112 f068d119 2022-09-02 stsp 					  c->left_start, c->left_count);
113 f068d119 2022-09-02 stsp 		else if (c->right_count && !c->left_count) {
114 f068d119 2022-09-02 stsp 			if (change)
115 f068d119 2022-09-02 stsp 				fprintf(dest, "---\n");
116 f068d119 2022-09-02 stsp 			rc = diff_output_lines(outinfo, dest,
117 f068d119 2022-09-02 stsp 					  c->solved ? "> " : "?",
118 f068d119 2022-09-02 stsp 					  c->right_start, c->right_count);
119 f068d119 2022-09-02 stsp 		}
120 f068d119 2022-09-02 stsp 		if (rc)
121 f068d119 2022-09-02 stsp 			return rc;
122 f068d119 2022-09-02 stsp 		if (cc->chunk.end == result->chunks.len) {
123 f068d119 2022-09-02 stsp 			rc = diff_output_trailing_newline_msg(outinfo, dest, c);
124 f068d119 2022-09-02 stsp 			if (rc != DIFF_RC_OK)
125 f068d119 2022-09-02 stsp 				return rc;
126 f068d119 2022-09-02 stsp 		}
127 f068d119 2022-09-02 stsp 	}
128 f068d119 2022-09-02 stsp 
129 f068d119 2022-09-02 stsp 	if (rc < 0)
130 f068d119 2022-09-02 stsp 		return errno;
131 f068d119 2022-09-02 stsp 	if (outinfo) {
132 f068d119 2022-09-02 stsp 		ARRAYLIST_ADD(offp, outinfo->line_offsets);
133 f068d119 2022-09-02 stsp 		if (offp == NULL)
134 f068d119 2022-09-02 stsp 			return ENOMEM;
135 f068d119 2022-09-02 stsp 		outoff += rc;
136 f068d119 2022-09-02 stsp 		*offp = outoff;
137 f068d119 2022-09-02 stsp 	}
138 f068d119 2022-09-02 stsp 
139 f068d119 2022-09-02 stsp 	return DIFF_RC_OK;
140 f068d119 2022-09-02 stsp }
141 f068d119 2022-09-02 stsp 
142 fe621944 2020-11-10 stsp int
143 f068d119 2022-09-02 stsp diff_output_plain(struct diff_output_info **output_info,
144 f068d119 2022-09-02 stsp     FILE *dest, const struct diff_input_info *info,
145 f068d119 2022-09-02 stsp     const struct diff_result *result)
146 fe621944 2020-11-10 stsp {
147 fe621944 2020-11-10 stsp 	struct diff_output_info *outinfo = NULL;
148 f068d119 2022-09-02 stsp 	struct diff_chunk_context cc = {};
149 f068d119 2022-09-02 stsp 	int atomizer_flags = (result->left->atomizer_flags|
150 f068d119 2022-09-02 stsp 	    result->right->atomizer_flags);
151 f068d119 2022-09-02 stsp 	int flags = (result->left->root->diff_flags |
152 f068d119 2022-09-02 stsp 	    result->right->root->diff_flags);
153 f068d119 2022-09-02 stsp 	bool force_text = (flags & DIFF_FLAG_FORCE_TEXT_DATA);
154 f068d119 2022-09-02 stsp 	bool have_binary = (atomizer_flags & DIFF_ATOMIZER_FOUND_BINARY_DATA);
155 fe621944 2020-11-10 stsp 	int i, rc;
156 fe621944 2020-11-10 stsp 
157 fe621944 2020-11-10 stsp 	if (!result)
158 fe621944 2020-11-10 stsp 		return EINVAL;
159 fe621944 2020-11-10 stsp 	if (result->rc != DIFF_RC_OK)
160 fe621944 2020-11-10 stsp 		return result->rc;
161 f068d119 2022-09-02 stsp 
162 fe621944 2020-11-10 stsp 	if (output_info) {
163 fe621944 2020-11-10 stsp 		*output_info = diff_output_info_alloc();
164 fe621944 2020-11-10 stsp 		if (*output_info == NULL)
165 f068d119 2022-09-02 stsp 			return ENOMEM;
166 fe621944 2020-11-10 stsp 		outinfo = *output_info;
167 fe621944 2020-11-10 stsp 	}
168 fe621944 2020-11-10 stsp 
169 f068d119 2022-09-02 stsp 	if (have_binary && !force_text) {
170 f068d119 2022-09-02 stsp 		for (i = 0; i < result->chunks.len; i++) {
171 f068d119 2022-09-02 stsp 			struct diff_chunk *c = &result->chunks.head[i];
172 f068d119 2022-09-02 stsp 			enum diff_chunk_type t = diff_chunk_type(c);
173 f068d119 2022-09-02 stsp 
174 f068d119 2022-09-02 stsp 			if (t != CHUNK_MINUS && t != CHUNK_PLUS)
175 f068d119 2022-09-02 stsp 				continue;
176 f068d119 2022-09-02 stsp 
177 f068d119 2022-09-02 stsp 			fprintf(dest, "Binary files %s and %s differ\n",
178 f068d119 2022-09-02 stsp 			    diff_output_get_label_left(info),
179 f068d119 2022-09-02 stsp 			    diff_output_get_label_right(info));
180 f068d119 2022-09-02 stsp 			break;
181 f068d119 2022-09-02 stsp 		}
182 f068d119 2022-09-02 stsp 
183 f068d119 2022-09-02 stsp 		return DIFF_RC_OK;
184 f068d119 2022-09-02 stsp 	}
185 f068d119 2022-09-02 stsp 
186 fe621944 2020-11-10 stsp 	for (i = 0; i < result->chunks.len; i++) {
187 f068d119 2022-09-02 stsp 		struct diff_chunk *chunk = &result->chunks.head[i];
188 f068d119 2022-09-02 stsp 		enum diff_chunk_type t = diff_chunk_type(chunk);
189 f068d119 2022-09-02 stsp 		struct diff_chunk_context next;
190 f068d119 2022-09-02 stsp 
191 f068d119 2022-09-02 stsp 		if (t != CHUNK_MINUS && t != CHUNK_PLUS)
192 f068d119 2022-09-02 stsp 			continue;
193 f068d119 2022-09-02 stsp 
194 f068d119 2022-09-02 stsp 		if (diff_chunk_context_empty(&cc)) {
195 f068d119 2022-09-02 stsp 			/* Note down the start point, any number of subsequent
196 f068d119 2022-09-02 stsp 			 * chunks may be joined up to this chunk by being
197 f068d119 2022-09-02 stsp 			 * directly adjacent. */
198 f068d119 2022-09-02 stsp 			diff_chunk_context_get(&cc, result, i, 0);
199 f068d119 2022-09-02 stsp 			continue;
200 f068d119 2022-09-02 stsp 		}
201 f068d119 2022-09-02 stsp 
202 f068d119 2022-09-02 stsp 		/* There already is a previous chunk noted down for being
203 f068d119 2022-09-02 stsp 		 * printed. Does it join up with this one? */
204 f068d119 2022-09-02 stsp 		diff_chunk_context_get(&next, result, i, 0);
205 f068d119 2022-09-02 stsp 
206 f068d119 2022-09-02 stsp 		if (diff_chunk_contexts_touch(&cc, &next)) {
207 f068d119 2022-09-02 stsp 			/* This next context touches or overlaps the previous
208 f068d119 2022-09-02 stsp 			 * one, join. */
209 f068d119 2022-09-02 stsp 			diff_chunk_contexts_merge(&cc, &next);
210 f068d119 2022-09-02 stsp 			/* When we merge the last chunk we can end up with one
211 f068d119 2022-09-02 stsp 			 * hanging chunk and have to come back for it after the
212 f068d119 2022-09-02 stsp 			 * loop */
213 f068d119 2022-09-02 stsp 			continue;
214 f068d119 2022-09-02 stsp 		}
215 f068d119 2022-09-02 stsp 		rc = output_plain_chunk(outinfo, dest, info, result, &cc);
216 f068d119 2022-09-02 stsp 		if (rc != DIFF_RC_OK)
217 fe621944 2020-11-10 stsp 			return rc;
218 f068d119 2022-09-02 stsp 		cc = next;
219 fe621944 2020-11-10 stsp 	}
220 f068d119 2022-09-02 stsp 	if (!diff_chunk_context_empty(&cc))
221 f068d119 2022-09-02 stsp 		return output_plain_chunk(outinfo, dest, info, result, &cc);
222 fe621944 2020-11-10 stsp 	return DIFF_RC_OK;
223 fe621944 2020-11-10 stsp }