1 /*
2 * Copyright (C) the libgit2 contributors. All rights reserved.
3 *
4 * This file is part of libgit2, distributed under the GNU GPL v2 with
5 * a Linking Exception. For full terms see the included COPYING file.
6 */
7
8 #include "diff_xdiff.h"
9 #include "util.h"
10
11 #include "git2/errors.h"
12 #include "diff.h"
13 #include "diff_driver.h"
14 #include "patch_generate.h"
15
git_xdiff_scan_int(const char ** str,int * value)16 static int git_xdiff_scan_int(const char **str, int *value)
17 {
18 const char *scan = *str;
19 int v = 0, digits = 0;
20 /* find next digit */
21 for (scan = *str; *scan && !git__isdigit(*scan); scan++);
22 /* parse next number */
23 for (; git__isdigit(*scan); scan++, digits++)
24 v = (v * 10) + (*scan - '0');
25 *str = scan;
26 *value = v;
27 return (digits > 0) ? 0 : -1;
28 }
29
git_xdiff_parse_hunk(git_diff_hunk * hunk,const char * header)30 static int git_xdiff_parse_hunk(git_diff_hunk *hunk, const char *header)
31 {
32 /* expect something of the form "@@ -%d[,%d] +%d[,%d] @@" */
33 if (*header != '@')
34 goto fail;
35 if (git_xdiff_scan_int(&header, &hunk->old_start) < 0)
36 goto fail;
37 if (*header == ',') {
38 if (git_xdiff_scan_int(&header, &hunk->old_lines) < 0)
39 goto fail;
40 } else
41 hunk->old_lines = 1;
42 if (git_xdiff_scan_int(&header, &hunk->new_start) < 0)
43 goto fail;
44 if (*header == ',') {
45 if (git_xdiff_scan_int(&header, &hunk->new_lines) < 0)
46 goto fail;
47 } else
48 hunk->new_lines = 1;
49 if (hunk->old_start < 0 || hunk->new_start < 0)
50 goto fail;
51
52 return 0;
53
54 fail:
55 git_error_set(GIT_ERROR_INVALID, "malformed hunk header from xdiff");
56 return -1;
57 }
58
59 typedef struct {
60 git_xdiff_output *xo;
61 git_patch_generated *patch;
62 git_diff_hunk hunk;
63 int old_lineno, new_lineno;
64 mmfile_t xd_old_data, xd_new_data;
65 } git_xdiff_info;
66
diff_update_lines(git_xdiff_info * info,git_diff_line * line,const char * content,size_t content_len)67 static int diff_update_lines(
68 git_xdiff_info *info,
69 git_diff_line *line,
70 const char *content,
71 size_t content_len)
72 {
73 const char *scan = content, *scan_end = content + content_len;
74
75 for (line->num_lines = 0; scan < scan_end; ++scan)
76 if (*scan == '\n')
77 ++line->num_lines;
78
79 line->content = content;
80 line->content_len = content_len;
81
82 /* expect " "/"-"/"+", then data */
83 switch (line->origin) {
84 case GIT_DIFF_LINE_ADDITION:
85 case GIT_DIFF_LINE_DEL_EOFNL:
86 line->old_lineno = -1;
87 line->new_lineno = info->new_lineno;
88 info->new_lineno += (int)line->num_lines;
89 break;
90 case GIT_DIFF_LINE_DELETION:
91 case GIT_DIFF_LINE_ADD_EOFNL:
92 line->old_lineno = info->old_lineno;
93 line->new_lineno = -1;
94 info->old_lineno += (int)line->num_lines;
95 break;
96 case GIT_DIFF_LINE_CONTEXT:
97 case GIT_DIFF_LINE_CONTEXT_EOFNL:
98 line->old_lineno = info->old_lineno;
99 line->new_lineno = info->new_lineno;
100 info->old_lineno += (int)line->num_lines;
101 info->new_lineno += (int)line->num_lines;
102 break;
103 default:
104 git_error_set(GIT_ERROR_INVALID, "unknown diff line origin %02x",
105 (unsigned int)line->origin);
106 return -1;
107 }
108
109 return 0;
110 }
111
git_xdiff_cb(void * priv,mmbuffer_t * bufs,int len)112 static int git_xdiff_cb(void *priv, mmbuffer_t *bufs, int len)
113 {
114 git_xdiff_info *info = priv;
115 git_patch_generated *patch = info->patch;
116 const git_diff_delta *delta = patch->base.delta;
117 git_patch_generated_output *output = &info->xo->output;
118 git_diff_line line;
119 size_t buffer_len;
120
121 if (len == 1) {
122 output->error = git_xdiff_parse_hunk(&info->hunk, bufs[0].ptr);
123 if (output->error < 0)
124 return output->error;
125
126 info->hunk.header_len = bufs[0].size;
127 if (info->hunk.header_len >= sizeof(info->hunk.header))
128 info->hunk.header_len = sizeof(info->hunk.header) - 1;
129
130 /* Sanitize the hunk header in case there is invalid Unicode */
131 buffer_len = git__utf8_valid_buf_length((const uint8_t *) bufs[0].ptr, info->hunk.header_len);
132 /* Sanitizing the hunk header may delete the newline, so add it back again if there is room */
133 if (buffer_len < info->hunk.header_len) {
134 bufs[0].ptr[buffer_len] = '\n';
135 buffer_len += 1;
136 info->hunk.header_len = buffer_len;
137 }
138
139 memcpy(info->hunk.header, bufs[0].ptr, info->hunk.header_len);
140 info->hunk.header[info->hunk.header_len] = '\0';
141
142 if (output->hunk_cb != NULL &&
143 (output->error = output->hunk_cb(
144 delta, &info->hunk, output->payload)))
145 return output->error;
146
147 info->old_lineno = info->hunk.old_start;
148 info->new_lineno = info->hunk.new_start;
149 }
150
151 if (len == 2 || len == 3) {
152 /* expect " "/"-"/"+", then data */
153 line.origin =
154 (*bufs[0].ptr == '+') ? GIT_DIFF_LINE_ADDITION :
155 (*bufs[0].ptr == '-') ? GIT_DIFF_LINE_DELETION :
156 GIT_DIFF_LINE_CONTEXT;
157
158 if (line.origin == GIT_DIFF_LINE_ADDITION)
159 line.content_offset = bufs[1].ptr - info->xd_new_data.ptr;
160 else if (line.origin == GIT_DIFF_LINE_DELETION)
161 line.content_offset = bufs[1].ptr - info->xd_old_data.ptr;
162 else
163 line.content_offset = -1;
164
165 output->error = diff_update_lines(
166 info, &line, bufs[1].ptr, bufs[1].size);
167
168 if (!output->error && output->data_cb != NULL)
169 output->error = output->data_cb(
170 delta, &info->hunk, &line, output->payload);
171 }
172
173 if (len == 3 && !output->error) {
174 /* If we have a '+' and a third buf, then we have added a line
175 * without a newline and the old code had one, so DEL_EOFNL.
176 * If we have a '-' and a third buf, then we have removed a line
177 * with out a newline but added a blank line, so ADD_EOFNL.
178 */
179 line.origin =
180 (*bufs[0].ptr == '+') ? GIT_DIFF_LINE_DEL_EOFNL :
181 (*bufs[0].ptr == '-') ? GIT_DIFF_LINE_ADD_EOFNL :
182 GIT_DIFF_LINE_CONTEXT_EOFNL;
183
184 line.content_offset = -1;
185
186 output->error = diff_update_lines(
187 info, &line, bufs[2].ptr, bufs[2].size);
188
189 if (!output->error && output->data_cb != NULL)
190 output->error = output->data_cb(
191 delta, &info->hunk, &line, output->payload);
192 }
193
194 return output->error;
195 }
196
git_xdiff(git_patch_generated_output * output,git_patch_generated * patch)197 static int git_xdiff(git_patch_generated_output *output, git_patch_generated *patch)
198 {
199 git_xdiff_output *xo = (git_xdiff_output *)output;
200 git_xdiff_info info;
201 git_diff_find_context_payload findctxt;
202
203 memset(&info, 0, sizeof(info));
204 info.patch = patch;
205 info.xo = xo;
206
207 xo->callback.priv = &info;
208
209 git_diff_find_context_init(
210 &xo->config.find_func, &findctxt, git_patch_generated_driver(patch));
211 xo->config.find_func_priv = &findctxt;
212
213 if (xo->config.find_func != NULL)
214 xo->config.flags |= XDL_EMIT_FUNCNAMES;
215 else
216 xo->config.flags &= ~XDL_EMIT_FUNCNAMES;
217
218 /* TODO: check ofile.opts_flags to see if driver-specific per-file
219 * updates are needed to xo->params.flags
220 */
221
222 git_patch_generated_old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch);
223 git_patch_generated_new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch);
224
225 if (info.xd_old_data.size > GIT_XDIFF_MAX_SIZE ||
226 info.xd_new_data.size > GIT_XDIFF_MAX_SIZE) {
227 git_error_set(GIT_ERROR_INVALID, "files too large for diff");
228 return -1;
229 }
230
231 xdl_diff(&info.xd_old_data, &info.xd_new_data,
232 &xo->params, &xo->config, &xo->callback);
233
234 git_diff_find_context_clear(&findctxt);
235
236 return xo->output.error;
237 }
238
git_xdiff_init(git_xdiff_output * xo,const git_diff_options * opts)239 void git_xdiff_init(git_xdiff_output *xo, const git_diff_options *opts)
240 {
241 uint32_t flags = opts ? opts->flags : 0;
242
243 xo->output.diff_cb = git_xdiff;
244
245 xo->config.ctxlen = opts ? opts->context_lines : 3;
246 xo->config.interhunkctxlen = opts ? opts->interhunk_lines : 0;
247
248 if (flags & GIT_DIFF_IGNORE_WHITESPACE)
249 xo->params.flags |= XDF_WHITESPACE_FLAGS;
250 if (flags & GIT_DIFF_IGNORE_WHITESPACE_CHANGE)
251 xo->params.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
252 if (flags & GIT_DIFF_IGNORE_WHITESPACE_EOL)
253 xo->params.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
254 if (flags & GIT_DIFF_INDENT_HEURISTIC)
255 xo->params.flags |= XDF_INDENT_HEURISTIC;
256
257 if (flags & GIT_DIFF_PATIENCE)
258 xo->params.flags |= XDF_PATIENCE_DIFF;
259 if (flags & GIT_DIFF_MINIMAL)
260 xo->params.flags |= XDF_NEED_MINIMAL;
261
262 xo->callback.outf = git_xdiff_cb;
263 }
264