1 fe621944 2020-11-10 stsp /* Produce ed(1) script 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  * Copyright (c) 2020 Stefan Sperling <stsp@openbsd.org>
  5 fe621944 2020-11-10 stsp  *
  6 fe621944 2020-11-10 stsp  * Permission to use, copy, modify, and distribute this software for any
  7 fe621944 2020-11-10 stsp  * purpose with or without fee is hereby granted, provided that the above
  8 fe621944 2020-11-10 stsp  * copyright notice and this permission notice appear in all copies.
  9 fe621944 2020-11-10 stsp  *
 10 fe621944 2020-11-10 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 11 fe621944 2020-11-10 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 12 fe621944 2020-11-10 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 13 fe621944 2020-11-10 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 14 fe621944 2020-11-10 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 15 fe621944 2020-11-10 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 16 fe621944 2020-11-10 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 17 fe621944 2020-11-10 stsp  */
 18 fe621944 2020-11-10 stsp 
 19 fe621944 2020-11-10 stsp #include <errno.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 fe621944 2020-11-10 stsp #include <stdbool.h>
 24 fe621944 2020-11-10 stsp 
 25 fe621944 2020-11-10 stsp #include <arraylist.h>
 26 fe621944 2020-11-10 stsp #include <diff_main.h>
 27 fe621944 2020-11-10 stsp #include <diff_output.h>
 28 fe621944 2020-11-10 stsp 
 29 fe621944 2020-11-10 stsp #include "diff_internal.h"
 30 fe621944 2020-11-10 stsp 
 31 fe621944 2020-11-10 stsp static int
 32 fe621944 2020-11-10 stsp output_edscript_chunk(struct diff_output_info *outinfo,
 33 fe621944 2020-11-10 stsp     FILE *dest, const struct diff_input_info *info,
 34 fe621944 2020-11-10 stsp     const struct diff_result *result,
 35 fe621944 2020-11-10 stsp     struct diff_chunk_context *cc)
 36 fe621944 2020-11-10 stsp {
 37 fe621944 2020-11-10 stsp 	off_t outoff = 0, *offp;
 38 fe621944 2020-11-10 stsp 	int left_start, left_len, right_start, right_len;
 39 fe621944 2020-11-10 stsp 	int rc;
 40 fe621944 2020-11-10 stsp 
 41 fe621944 2020-11-10 stsp 	left_len = cc->left.end - cc->left.start;
 42 fe621944 2020-11-10 stsp 	if (left_len < 0)
 43 fe621944 2020-11-10 stsp 		return EINVAL;
 44 fe621944 2020-11-10 stsp 	else if (result->left->atoms.len == 0)
 45 fe621944 2020-11-10 stsp 		left_start = 0;
 46 fe621944 2020-11-10 stsp 	else if (left_len == 0 && cc->left.start > 0)
 47 fe621944 2020-11-10 stsp 		left_start = cc->left.start;
 48 fe621944 2020-11-10 stsp 	else
 49 fe621944 2020-11-10 stsp 		left_start = cc->left.start + 1;
 50 fe621944 2020-11-10 stsp 
 51 fe621944 2020-11-10 stsp 	right_len = cc->right.end - cc->right.start;
 52 fe621944 2020-11-10 stsp 	if (right_len < 0)
 53 fe621944 2020-11-10 stsp 		return EINVAL;
 54 fe621944 2020-11-10 stsp 	else if (result->right->atoms.len == 0)
 55 fe621944 2020-11-10 stsp 		right_start = 0;
 56 fe621944 2020-11-10 stsp 	else if (right_len == 0 && cc->right.start > 0)
 57 fe621944 2020-11-10 stsp 		right_start = cc->right.start;
 58 fe621944 2020-11-10 stsp 	else
 59 fe621944 2020-11-10 stsp 		right_start = cc->right.start + 1;
 60 fe621944 2020-11-10 stsp 
 61 fe621944 2020-11-10 stsp 	if (left_len == 0) {
 62 fe621944 2020-11-10 stsp 		/* addition */
 63 fe621944 2020-11-10 stsp 		if (right_len == 1) {
 64 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%da%d\n", left_start, right_start);
 65 fe621944 2020-11-10 stsp 		} else {
 66 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%da%d,%d\n", left_start,
 67 fe621944 2020-11-10 stsp 			    right_start, cc->right.end);
 68 fe621944 2020-11-10 stsp 		}
 69 fe621944 2020-11-10 stsp 	} else if (right_len == 0) {
 70 fe621944 2020-11-10 stsp 		/* deletion */
 71 fe621944 2020-11-10 stsp 		if (left_len == 1) {
 72 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%dd%d\n", left_start,
 73 fe621944 2020-11-10 stsp 			    right_start);
 74 fe621944 2020-11-10 stsp 		} else {
 75 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%d,%dd%d\n", left_start,
 76 fe621944 2020-11-10 stsp 			    cc->left.end, right_start);
 77 fe621944 2020-11-10 stsp 		}
 78 fe621944 2020-11-10 stsp 	} else {
 79 fe621944 2020-11-10 stsp 		/* change */
 80 fe621944 2020-11-10 stsp 		if (left_len == 1 && right_len == 1) {
 81 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%dc%d\n", left_start, right_start);
 82 fe621944 2020-11-10 stsp 		} else if (left_len == 1) {
 83 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%dc%d,%d\n", left_start,
 84 fe621944 2020-11-10 stsp 			    right_start, cc->right.end);
 85 fe621944 2020-11-10 stsp 		} else if (right_len == 1) {
 86 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%d,%dc%d\n", left_start,
 87 fe621944 2020-11-10 stsp 			    cc->left.end, right_start);
 88 fe621944 2020-11-10 stsp 		} else {
 89 fe621944 2020-11-10 stsp 			rc = fprintf(dest, "%d,%dc%d,%d\n", left_start,
 90 fe621944 2020-11-10 stsp 			    cc->left.end, right_start, cc->right.end);
 91 fe621944 2020-11-10 stsp 		}
 92 fe621944 2020-11-10 stsp 	}
 93 fe621944 2020-11-10 stsp 	if (rc < 0)
 94 fe621944 2020-11-10 stsp 		return errno;
 95 fe621944 2020-11-10 stsp 	if (outinfo) {
 96 fe621944 2020-11-10 stsp 		ARRAYLIST_ADD(offp, outinfo->line_offsets);
 97 fe621944 2020-11-10 stsp 		if (offp == NULL)
 98 fe621944 2020-11-10 stsp 			return ENOMEM;
 99 fe621944 2020-11-10 stsp 		outoff += rc;
100 fe621944 2020-11-10 stsp 		*offp = outoff;
101 fe621944 2020-11-10 stsp 	}
102 fe621944 2020-11-10 stsp 
103 fe621944 2020-11-10 stsp 	return DIFF_RC_OK;
104 fe621944 2020-11-10 stsp }
105 fe621944 2020-11-10 stsp 
106 fe621944 2020-11-10 stsp int
107 fe621944 2020-11-10 stsp diff_output_edscript(struct diff_output_info **output_info,
108 fe621944 2020-11-10 stsp     FILE *dest, const struct diff_input_info *info,
109 fe621944 2020-11-10 stsp     const struct diff_result *result)
110 fe621944 2020-11-10 stsp {
111 fe621944 2020-11-10 stsp 	struct diff_output_info *outinfo = NULL;
112 fe621944 2020-11-10 stsp 	struct diff_chunk_context cc = {};
113 fe621944 2020-11-10 stsp 	int i, rc;
114 fe621944 2020-11-10 stsp 
115 fe621944 2020-11-10 stsp 	if (!result)
116 fe621944 2020-11-10 stsp 		return EINVAL;
117 fe621944 2020-11-10 stsp 	if (result->rc != DIFF_RC_OK)
118 fe621944 2020-11-10 stsp 		return result->rc;
119 fe621944 2020-11-10 stsp 
120 fe621944 2020-11-10 stsp 	if (output_info) {
121 fe621944 2020-11-10 stsp 		*output_info = diff_output_info_alloc();
122 fe621944 2020-11-10 stsp 		if (*output_info == NULL)
123 fe621944 2020-11-10 stsp 			return ENOMEM;
124 fe621944 2020-11-10 stsp 		outinfo = *output_info;
125 fe621944 2020-11-10 stsp 	}
126 fe621944 2020-11-10 stsp 
127 fe621944 2020-11-10 stsp 	for (i = 0; i < result->chunks.len; i++) {
128 fe621944 2020-11-10 stsp 		struct diff_chunk *chunk = &result->chunks.head[i];
129 fe621944 2020-11-10 stsp 		enum diff_chunk_type t = diff_chunk_type(chunk);
130 fe621944 2020-11-10 stsp 		struct diff_chunk_context next;
131 fe621944 2020-11-10 stsp 
132 fe621944 2020-11-10 stsp 		if (t != CHUNK_MINUS && t != CHUNK_PLUS)
133 fe621944 2020-11-10 stsp 			continue;
134 fe621944 2020-11-10 stsp 
135 fe621944 2020-11-10 stsp 		if (diff_chunk_context_empty(&cc)) {
136 fe621944 2020-11-10 stsp 			/* Note down the start point, any number of subsequent
137 fe621944 2020-11-10 stsp 			 * chunks may be joined up to this chunk by being
138 fe621944 2020-11-10 stsp 			 * directly adjacent. */
139 fe621944 2020-11-10 stsp 			diff_chunk_context_get(&cc, result, i, 0);
140 fe621944 2020-11-10 stsp 			continue;
141 fe621944 2020-11-10 stsp 		}
142 fe621944 2020-11-10 stsp 
143 fe621944 2020-11-10 stsp 		/* There already is a previous chunk noted down for being
144 fe621944 2020-11-10 stsp 		 * printed. Does it join up with this one? */
145 fe621944 2020-11-10 stsp 		diff_chunk_context_get(&next, result, i, 0);
146 fe621944 2020-11-10 stsp 
147 fe621944 2020-11-10 stsp 		if (diff_chunk_contexts_touch(&cc, &next)) {
148 fe621944 2020-11-10 stsp 			/* This next context touches or overlaps the previous
149 fe621944 2020-11-10 stsp 			 * one, join. */
150 fe621944 2020-11-10 stsp 			diff_chunk_contexts_merge(&cc, &next);
151 fe621944 2020-11-10 stsp 			continue;
152 fe621944 2020-11-10 stsp 		}
153 fe621944 2020-11-10 stsp 
154 fe621944 2020-11-10 stsp 		rc = output_edscript_chunk(outinfo, dest, info, result, &cc);
155 fe621944 2020-11-10 stsp 		if (rc != DIFF_RC_OK)
156 fe621944 2020-11-10 stsp 			return rc;
157 fe621944 2020-11-10 stsp 		cc = next;
158 fe621944 2020-11-10 stsp 	}
159 fe621944 2020-11-10 stsp 
160 fe621944 2020-11-10 stsp 	if (!diff_chunk_context_empty(&cc))
161 fe621944 2020-11-10 stsp 		return output_edscript_chunk(outinfo, dest, info, result, &cc);
162 fe621944 2020-11-10 stsp 	return DIFF_RC_OK;
163 fe621944 2020-11-10 stsp }