From a4acb0eb140d80141ac564a09219a10c3ab76449 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 23 May 2005 16:09:09 -0700 Subject: [PATCH 1/1] git-apply: parse the diff headers (both traditional and new) .. and print out the information. This sets up all the pathname information, and whether it's a new file, deleted file, rename, copy or whatever. It's slowly getting to the point where it all comes together, and we can actually apply all the information that we've gathered. --- apply.c | 248 +++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 217 insertions(+), 31 deletions(-) diff --git a/apply.c b/apply.c index 05f921a31..c3c7e6da5 100644 --- a/apply.c +++ b/apply.c @@ -21,9 +21,18 @@ static int merge_patch = 1; static const char apply_usage[] = "git-apply "; +/* + * Various "current state", notably line numbers and what + * file (and how) we're patching right now.. The "is_xxxx" + * things are flags, where -1 means "don't know yet". + */ static int linenr = 1; +static int old_mode, new_mode; +static char *old_name, *new_name, *def_name; +static int is_rename, is_copy, is_new, is_delete; #define CHUNKSIZE (8192) +#define SLOP (16) static void *read_patch_file(int fd, unsigned long *sizep) { @@ -48,6 +57,15 @@ static void *read_patch_file(int fd, unsigned long *sizep) size += nr; } *sizep = size; + + /* + * Make sure that we have some slop in the buffer + * so that we can do speculative "memcmp" etc, and + * see to it that it is NUL-filled. + */ + if (alloc < size + SLOP) + buffer = xrealloc(buffer, size + SLOP); + memset(buffer + size, 0, SLOP); return buffer; } @@ -62,48 +80,200 @@ static unsigned long linelen(char *buffer, unsigned long size) return len; } -static int match_word(const char *line, const char *match) +static int is_dev_null(const char *str) +{ + return !memcmp("/dev/null", str, 9) && isspace(str[9]); +} + +static char * find_name(const char *line, char *def, int p_value) { + int len; + const char *start = line; + char *name; + for (;;) { - char c = *match++; - if (!c) + char c = *line; + if (isspace(c)) break; - if (*line++ != c) - return 0; + line++; + if (c == '/' && !--p_value) + start = line; + } + if (!start) + return def; + len = line - start; + if (!len) + return def; + + /* + * Generally we prefer the shorter name, especially + * if the other one is just a variation of that with + * something else tacked on to the end (ie "file.orig" + * or "file~"). + */ + if (def) { + int deflen = strlen(def); + if (deflen < len && !strncmp(start, def, deflen)) + return def; } - return *line == ' '; + + name = xmalloc(len + 1); + memcpy(name, start, len); + name[len] = 0; + free(def); + return name; +} + +/* + * Get the name etc info from the --/+++ lines of a traditional patch header + * + * NOTE! This hardcodes "-p1" behaviour in filename detection. + */ +static int parse_traditional_patch(const char *first, const char *second) +{ + int p_value = 1; + char *name; + + first += 4; // skip "--- " + second += 4; // skip "+++ " + if (is_dev_null(first)) { + is_new = 1; + name = find_name(second, def_name, p_value); + } else if (is_dev_null(second)) { + is_delete = 1; + name = find_name(first, def_name, p_value); + } else { + name = find_name(first, def_name, p_value); + name = find_name(second, name, p_value); + } + if (!name) + die("unable to find filename in patch at line %d", linenr); + old_name = name; + new_name = name; +} + +static int gitdiff_hdrend(const char *line) +{ + return -1; +} + +static int gitdiff_oldname(const char *line) +{ + if (!old_name) + old_name = find_name(line, NULL, 1); + return 0; +} + +static int gitdiff_newname(const char *line) +{ + if (!new_name) + new_name = find_name(line, NULL, 1); + return 0; +} + +static int gitdiff_oldmode(const char *line) +{ + old_mode = strtoul(line, NULL, 8); + return 0; +} + +static int gitdiff_newmode(const char *line) +{ + new_mode = strtoul(line, NULL, 8); + return 0; +} + +static int gitdiff_delete(const char *line) +{ + is_delete = 1; + return gitdiff_oldmode(line); +} + +static int gitdiff_newfile(const char *line) +{ + is_new = 1; + return gitdiff_newmode(line); +} + +static int gitdiff_copysrc(const char *line) +{ + is_copy = 1; + old_name = find_name(line, NULL, 0); + return 0; +} + +static int gitdiff_copydst(const char *line) +{ + is_copy = 1; + new_name = find_name(line, NULL, 0); + return 0; +} + +static int gitdiff_renamesrc(const char *line) +{ + is_rename = 1; + old_name = find_name(line, NULL, 0); + return 0; +} + +static int gitdiff_renamedst(const char *line) +{ + is_rename = 1; + new_name = find_name(line, NULL, 0); + return 0; +} + +static int gitdiff_similarity(const char *line) +{ + return 0; } /* Verify that we recognize the lines following a git header */ -static int parse_git_header(char *line, unsigned int size) +static int parse_git_header(char *line, int len, unsigned int size) { - unsigned long offset, len; + unsigned long offset; + + /* A git diff has explicit new/delete information, so we don't guess */ + is_new = 0; + is_delete = 0; + + line += len; + size -= len; + linenr++; + for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) { + static const struct opentry { + const char *str; + int (*fn)(const char *); + } optable[] = { + { "@@ -", gitdiff_hdrend }, + { "--- ", gitdiff_oldname }, + { "+++ ", gitdiff_newname }, + { "old mode ", gitdiff_oldmode }, + { "new mode ", gitdiff_newmode }, + { "deleted file mode ", gitdiff_delete }, + { "new file mode ", gitdiff_newfile }, + { "copy from ", gitdiff_copysrc }, + { "copy to ", gitdiff_copydst }, + { "rename from ", gitdiff_renamesrc }, + { "rename to ", gitdiff_renamedst }, + { "similarity index ", gitdiff_similarity }, + }; + int i; - for (offset = 0 ; size > 0 ; offset += len, size -= len, line += len, linenr++) { len = linelen(line, size); - if (!len) - break; - if (line[len-1] != '\n') - return -1; - if (len < 4) + if (!len || line[len-1] != '\n') break; - if (!memcmp(line, "@@ -", 4)) - return offset; - if (match_word(line, "new file mode")) - continue; - if (match_word(line, "deleted file mode")) - continue; - if (match_word(line, "copy")) - continue; - if (match_word(line, "rename")) - continue; - if (match_word(line, "similarity index")) - continue; - break; + for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) { + const struct opentry *p = optable + i; + int oplen = strlen(p->str); + if (len < oplen || memcmp(p->str, line, oplen)) + continue; + if (p->fn(line + oplen) < 0) + return offset; + } } - /* We want either a patch _or_ something real */ - return offset ? :-1; + return offset; } static int parse_num(const char *line, int len, int offset, const char *expect, unsigned long *p) @@ -159,6 +329,10 @@ static int find_header(char *line, unsigned long size, int *hdrsize) { unsigned long offset, len; + is_rename = is_copy = 0; + is_new = is_delete = -1; + old_mode = new_mode = -1; + def_name = old_name = new_name = NULL; for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) { unsigned long nextlen; @@ -190,11 +364,11 @@ static int find_header(char *line, unsigned long size, int *hdrsize) * or mode change, so we handle that specially */ if (!memcmp("diff --git ", line, 11)) { - int git_hdr_len = parse_git_header(line + len, size - len); + int git_hdr_len = parse_git_header(line, len, size); if (git_hdr_len < 0) continue; - *hdrsize = len + git_hdr_len; + *hdrsize = git_hdr_len; return offset; } @@ -212,6 +386,7 @@ static int find_header(char *line, unsigned long size, int *hdrsize) continue; /* Ok, we'll consider it a patch */ + parse_traditional_patch(line, line+len); *hdrsize = len + nextlen; linenr += 2; return offset; @@ -237,6 +412,11 @@ static int apply_fragment(char *line, unsigned long size) oldlines = pos[1]; newlines = pos[3]; + if (is_new < 0 && (pos[0] || oldlines)) + is_new = 0; + if (is_delete < 0 && (pos[1] || newlines)) + is_delete = 0; + /* Parse the thing.. */ line += len; size -= len; @@ -294,6 +474,12 @@ static int apply_chunk(char *buffer, unsigned long size) header = buffer + offset; printf("Found header:\n%.*s\n\n", hdrsize, header); +printf("Rename: %d\n", is_rename); +printf("Copy: %d\n", is_copy); +printf("New: %d\n", is_new); +printf("Delete: %d\n", is_delete); +printf("Mode: %o->%o\n", old_mode, new_mode); +printf("Name: '%s'->'%s'\n", old_name, new_name); patch = header + hdrsize; patchsize = apply_single_patch(patch, size - offset - hdrsize); -- 2.45.2