diff options
Diffstat (limited to 'contrib/libdiff/lib/diff_output_edscript.c')
| -rw-r--r-- | contrib/libdiff/lib/diff_output_edscript.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/contrib/libdiff/lib/diff_output_edscript.c b/contrib/libdiff/lib/diff_output_edscript.c new file mode 100644 index 000000000000..42d4d5b39ef5 --- /dev/null +++ b/contrib/libdiff/lib/diff_output_edscript.c @@ -0,0 +1,190 @@ +/* Produce ed(1) script output from a diff_result. */ +/* + * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de> + * Copyright (c) 2020 Stefan Sperling <stsp@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <errno.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> + +#include <arraylist.h> +#include <diff_main.h> +#include <diff_output.h> + +#include "diff_internal.h" + +static int +output_edscript_chunk(struct diff_output_info *outinfo, + FILE *dest, const struct diff_input_info *info, + const struct diff_result *result, + struct diff_chunk_context *cc) +{ + off_t outoff = 0, *offp; + int left_start, left_len, right_start, right_len; + int rc; + + left_len = cc->left.end - cc->left.start; + if (left_len < 0) + return EINVAL; + else if (result->left->atoms.len == 0) + left_start = 0; + else if (left_len == 0 && cc->left.start > 0) + left_start = cc->left.start; + else if (cc->left.end > 0) + left_start = cc->left.start + 1; + else + left_start = cc->left.start; + + right_len = cc->right.end - cc->right.start; + if (right_len < 0) + return EINVAL; + else if (result->right->atoms.len == 0) + right_start = 0; + else if (right_len == 0 && cc->right.start > 0) + right_start = cc->right.start; + else if (cc->right.end > 0) + right_start = cc->right.start + 1; + else + right_start = cc->right.start; + + if (left_len == 0) { + /* addition */ + if (right_len == 1) { + rc = fprintf(dest, "%da%d\n", left_start, right_start); + } else { + rc = fprintf(dest, "%da%d,%d\n", left_start, + right_start, cc->right.end); + } + } else if (right_len == 0) { + /* deletion */ + if (left_len == 1) { + rc = fprintf(dest, "%dd%d\n", left_start, + right_start); + } else { + rc = fprintf(dest, "%d,%dd%d\n", left_start, + cc->left.end, right_start); + } + } else { + /* change */ + if (left_len == 1 && right_len == 1) { + rc = fprintf(dest, "%dc%d\n", left_start, right_start); + } else if (left_len == 1) { + rc = fprintf(dest, "%dc%d,%d\n", left_start, + right_start, cc->right.end); + } else if (right_len == 1) { + rc = fprintf(dest, "%d,%dc%d\n", left_start, + cc->left.end, right_start); + } else { + rc = fprintf(dest, "%d,%dc%d,%d\n", left_start, + cc->left.end, right_start, cc->right.end); + } + } + if (rc < 0) + return errno; + if (outinfo) { + ARRAYLIST_ADD(offp, outinfo->line_offsets); + if (offp == NULL) + return ENOMEM; + outoff += rc; + *offp = outoff; + } + + return DIFF_RC_OK; +} + +int +diff_output_edscript(struct diff_output_info **output_info, + FILE *dest, const struct diff_input_info *info, + const struct diff_result *result) +{ + struct diff_output_info *outinfo = NULL; + struct diff_chunk_context cc = {}; + int atomizer_flags = (result->left->atomizer_flags| + result->right->atomizer_flags); + int flags = (result->left->root->diff_flags | + result->right->root->diff_flags); + bool force_text = (flags & DIFF_FLAG_FORCE_TEXT_DATA); + bool have_binary = (atomizer_flags & DIFF_ATOMIZER_FOUND_BINARY_DATA); + int i, rc; + + if (!result) + return EINVAL; + if (result->rc != DIFF_RC_OK) + return result->rc; + + if (output_info) { + *output_info = diff_output_info_alloc(); + if (*output_info == NULL) + return ENOMEM; + outinfo = *output_info; + } + + if (have_binary && !force_text) { + for (i = 0; i < result->chunks.len; i++) { + struct diff_chunk *c = &result->chunks.head[i]; + enum diff_chunk_type t = diff_chunk_type(c); + + if (t != CHUNK_MINUS && t != CHUNK_PLUS) + continue; + + fprintf(dest, "Binary files %s and %s differ\n", + diff_output_get_label_left(info), + diff_output_get_label_right(info)); + break; + } + + return DIFF_RC_OK; + } + + for (i = 0; i < result->chunks.len; i++) { + struct diff_chunk *chunk = &result->chunks.head[i]; + enum diff_chunk_type t = diff_chunk_type(chunk); + struct diff_chunk_context next; + + if (t != CHUNK_MINUS && t != CHUNK_PLUS) + continue; + + if (diff_chunk_context_empty(&cc)) { + /* Note down the start point, any number of subsequent + * chunks may be joined up to this chunk by being + * directly adjacent. */ + diff_chunk_context_get(&cc, result, i, 0); + continue; + } + + /* There already is a previous chunk noted down for being + * printed. Does it join up with this one? */ + diff_chunk_context_get(&next, result, i, 0); + + if (diff_chunk_contexts_touch(&cc, &next)) { + /* This next context touches or overlaps the previous + * one, join. */ + diff_chunk_contexts_merge(&cc, &next); + continue; + } + + rc = output_edscript_chunk(outinfo, dest, info, result, &cc); + if (rc != DIFF_RC_OK) + return rc; + cc = next; + } + + if (!diff_chunk_context_empty(&cc)) + return output_edscript_chunk(outinfo, dest, info, result, &cc); + return DIFF_RC_OK; +} |