#include "cache.h" #include "attr.h" #include "run-command.h" /* * convert.c - convert a file when checking it out and checking it in. * * This should use the pathname to decide on whether it wants to do some * more interesting conversions (automatic gzip/unzip, general format * conversions etc etc), but by default it just does automatic CRLF<->LF * translation when the "auto_crlf" option is set. */ #define CRLF_GUESS (-1) #define CRLF_BINARY 0 #define CRLF_TEXT 1 #define CRLF_INPUT 2 struct text_stat { /* CR, LF and CRLF counts */ unsigned cr, lf, crlf; /* These are just approximations! */ unsigned printable, nonprintable; }; static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats) { unsigned long i; memset(stats, 0, sizeof(*stats)); for (i = 0; i < size; i++) { unsigned char c = buf[i]; if (c == '\r') { stats->cr++; if (i+1 < size && buf[i+1] == '\n') stats->crlf++; continue; } if (c == '\n') { stats->lf++; continue; } if (c == 127) /* DEL */ stats->nonprintable++; else if (c < 32) { switch (c) { /* BS, HT, ESC and FF */ case '\b': case '\t': case '\033': case '\014': stats->printable++; break; default: stats->nonprintable++; } } else stats->printable++; } } /* * The same heuristics as diff.c::mmfile_is_binary() */ static int is_binary(unsigned long size, struct text_stat *stats) { if ((stats->printable >> 7) < stats->nonprintable) return 1; /* * Other heuristics? Average line length might be relevant, * as might LF vs CR vs CRLF counts.. * * NOTE! It might be normal to have a low ratio of CRLF to LF * (somebody starts with a LF-only file and edits it with an editor * that adds CRLF only to lines that are added..). But do we * want to support CR-only? Probably not. */ return 0; } static char *crlf_to_git(const char *path, const char *src, unsigned long *sizep, int action) { char *buffer, *dst; unsigned long size, nsize; struct text_stat stats; if ((action == CRLF_BINARY) || !auto_crlf) return NULL; size = *sizep; if (!size) return NULL; gather_stats(src, size, &stats); /* No CR? Nothing to convert, regardless. */ if (!stats.cr) return NULL; if (action == CRLF_GUESS) { /* * We're currently not going to even try to convert stuff * that has bare CR characters. Does anybody do that crazy * stuff? */ if (stats.cr != stats.crlf) return NULL; /* * And add some heuristics for binary vs text, of course... */ if (is_binary(size, &stats)) return NULL; } /* * Ok, allocate a new buffer, fill it in, and return it * to let the caller know that we switched buffers. */ nsize = size - stats.crlf; buffer = xmalloc(nsize); *sizep = nsize; dst = buffer; if (action == CRLF_GUESS) { /* * If we guessed, we already know we rejected a file with * lone CR, and we can strip a CR without looking at what * follow it. */ do { unsigned char c = *src++; if (c != '\r') *dst++ = c; } while (--size); } else { do { unsigned char c = *src++; if (! (c == '\r' && (1 < size && *src == '\n'))) *dst++ = c; } while (--size); } return buffer; } static char *crlf_to_worktree(const char *path, const char *src, unsigned long *sizep, int action) { char *buffer, *dst; unsigned long size, nsize; struct text_stat stats; unsigned char last; if ((action == CRLF_BINARY) || (action == CRLF_INPUT) || auto_crlf <= 0) return NULL; size = *sizep; if (!size) return NULL; gather_stats(src, size, &stats); /* No LF? Nothing to convert, regardless. */ if (!stats.lf) return NULL; /* Was it already in CRLF format? */ if (stats.lf == stats.crlf) return NULL; if (action == CRLF_GUESS) { /* If we have any bare CR characters, we're not going to touch it */ if (stats.cr != stats.crlf) return NULL; if (is_binary(size, &stats)) return NULL; } /* * Ok, allocate a new buffer, fill it in, and return it * to let the caller know that we switched buffers. */ nsize = size + stats.lf - stats.crlf; buffer = xmalloc(nsize); *sizep = nsize; last = 0; dst = buffer; do { unsigned char c = *src++; if (c == '\n' && last != '\r') *dst++ = '\r'; *dst++ = c; last = c; } while (--size); return buffer; } static int filter_buffer(const char *path, const char *src, unsigned long size, const char *cmd) { /* * Spawn cmd and feed the buffer contents through its stdin. */ struct child_process child_process; int pipe_feed[2]; int write_err, status; memset(&child_process, 0, sizeof(child_process)); if (pipe(pipe_feed) < 0) { error("cannot create pipe to run external filter %s", cmd); return 1; } child_process.pid = fork(); if (child_process.pid < 0) { error("cannot fork to run external filter %s", cmd); close(pipe_feed[0]); close(pipe_feed[1]); return 1; } if (!child_process.pid) { dup2(pipe_feed[0], 0); close(pipe_feed[0]); close(pipe_feed[1]); execlp("sh", "sh", "-c", cmd, NULL); return 1; } close(pipe_feed[0]); write_err = (write_in_full(pipe_feed[1], src, size) < 0); if (close(pipe_feed[1])) write_err = 1; if (write_err) error("cannot feed the input to external filter %s", cmd); status = finish_command(&child_process); if (status) error("external filter %s failed %d", cmd, -status); return (write_err || status); } static char *apply_filter(const char *path, const char *src, unsigned long *sizep, const char *cmd) { /* * Create a pipeline to have the command filter the buffer's * contents. * * (child --> cmd) --> us */ const int SLOP = 4096; int pipe_feed[2]; int status; char *dst; unsigned long dstsize, dstalloc; struct child_process child_process; if (!cmd) return NULL; memset(&child_process, 0, sizeof(child_process)); if (pipe(pipe_feed) < 0) { error("cannot create pipe to run external filter %s", cmd); return NULL; } fflush(NULL); child_process.pid = fork(); if (child_process.pid < 0) { error("cannot fork to run external filter %s", cmd); close(pipe_feed[0]); close(pipe_feed[1]); return NULL; } if (!child_process.pid) { dup2(pipe_feed[1], 1); close(pipe_feed[0]); close(pipe_feed[1]); exit(filter_buffer(path, src, *sizep, cmd)); } close(pipe_feed[1]); dstalloc = *sizep; dst = xmalloc(dstalloc); dstsize = 0; while (1) { ssize_t numread = xread(pipe_feed[0], dst + dstsize, dstalloc - dstsize); if (numread <= 0) { if (!numread) break; error("read from external filter %s failed", cmd); free(dst); dst = NULL; break; } dstsize += numread; if (dstalloc <= dstsize + SLOP) { dstalloc = dstsize + SLOP; dst = xrealloc(dst, dstalloc); } } if (close(pipe_feed[0])) { error("read from external filter %s failed", cmd); free(dst); dst = NULL; } status = finish_command(&child_process); if (status) { error("external filter %s failed %d", cmd, -status); free(dst); dst = NULL; } if (dst) *sizep = dstsize; return dst; } static struct convert_driver { const char *name; struct convert_driver *next; char *smudge; char *clean; } *user_convert, **user_convert_tail; static int read_convert_config(const char *var, const char *value) { const char *ep, *name; int namelen; struct convert_driver *drv; /* * External conversion drivers are configured using * "filter.<name>.variable". */ if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6) return 0; name = var + 7; namelen = ep - name; for (drv = user_convert; drv; drv = drv->next) if (!strncmp(drv->name, name, namelen) && !drv->name[namelen]) break; if (!drv) { char *namebuf; drv = xcalloc(1, sizeof(struct convert_driver)); namebuf = xmalloc(namelen + 1); memcpy(namebuf, name, namelen); namebuf[namelen] = 0; drv->name = namebuf; drv->next = NULL; *user_convert_tail = drv; user_convert_tail = &(drv->next); } ep++; /* * filter.<name>.smudge and filter.<name>.clean specifies * the command line: * * command-line * * The command-line will not be interpolated in any way. */ if (!strcmp("smudge", ep)) { if (!value) return error("%s: lacks value", var); drv->smudge = strdup(value); return 0; } if (!strcmp("clean", ep)) { if (!value) return error("%s: lacks value", var); drv->clean = strdup(value); return 0; } return 0; } static void setup_convert_check(struct git_attr_check *check) { static struct git_attr *attr_crlf; static struct git_attr *attr_ident; static struct git_attr *attr_filter; if (!attr_crlf) { attr_crlf = git_attr("crlf", 4); attr_ident = git_attr("ident", 5); attr_filter = git_attr("filter", 6); user_convert_tail = &user_convert; git_config(read_convert_config); } check[0].attr = attr_crlf; check[1].attr = attr_ident; check[2].attr = attr_filter; } static int count_ident(const char *cp, unsigned long size) { /* * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$" */ int cnt = 0; char ch; while (size) { ch = *cp++; size--; if (ch != '$') continue; if (size < 3) break; if (memcmp("Id", cp, 2)) continue; ch = cp[2]; cp += 3; size -= 3; if (ch == '$') cnt++; /* $Id$ */ if (ch != ':') continue; /* * "$Id: ... "; scan up to the closing dollar sign and discard. */ while (size) { ch = *cp++; size--; if (ch == '$') { cnt++; break; } } } return cnt; } static char *ident_to_git(const char *path, const char *src, unsigned long *sizep, int ident) { int cnt; unsigned long size; char *dst, *buf; if (!ident) return NULL; size = *sizep; cnt = count_ident(src, size); if (!cnt) return NULL; buf = xmalloc(size); for (dst = buf; size; size--) { char ch = *src++; *dst++ = ch; if ((ch == '$') && (3 <= size) && !memcmp("Id:", src, 3)) { unsigned long rem = size - 3; const char *cp = src + 3; do { ch = *cp++; if (ch == '$') break; rem--; } while (rem); if (!rem) continue; memcpy(dst, "Id$", 3); dst += 3; size -= (cp - src); src = cp; } } *sizep = dst - buf; return buf; } static char *ident_to_worktree(const char *path, const char *src, unsigned long *sizep, int ident) { int cnt; unsigned long size; char *dst, *buf; unsigned char sha1[20]; if (!ident) return NULL; size = *sizep; cnt = count_ident(src, size); if (!cnt) return NULL; hash_sha1_file(src, size, "blob", sha1); buf = xmalloc(size + cnt * 43); for (dst = buf; size; size--) { const char *cp; /* Fetch next source character, move the pointer on */ char ch = *src++; /* Copy the current character to the destination */ *dst++ = ch; /* If the current character is "$" or there are less than three * remaining bytes or the two bytes following this one are not * "Id", then simply read the next character */ if ((ch != '$') || (size < 3) || memcmp("Id", src, 2)) continue; /* * Here when * - There are more than 2 bytes remaining * - The current three bytes are "$Id" * with * - ch == "$" * - src[0] == "I" */ /* * It's possible that an expanded Id has crept its way into the * repository, we cope with that by stripping the expansion out */ if (src[2] == ':') { /* Expanded keywords have "$Id:" at the front */ /* discard up to but not including the closing $ */ unsigned long rem = size - 3; /* Point at first byte after the ":" */ cp = src + 3; /* * Throw away characters until either * - we reach a "$" * - we run out of bytes (rem == 0) */ do { ch = *cp; if (ch == '$') break; cp++; rem--; } while (rem); /* If the above finished because it ran out of characters, then * this is an incomplete keyword, so don't run the expansion */ if (!rem) continue; } else if (src[2] == '$') cp = src + 2; else /* Anything other than "$Id:XXX$" or $Id$ and we skip the * expansion */ continue; /* cp is now pointing at the last $ of the keyword */ memcpy(dst, "Id: ", 4); dst += 4; memcpy(dst, sha1_to_hex(sha1), 40); dst += 40; *dst++ = ' '; /* Adjust for the characters we've discarded */ size -= (cp - src); src = cp; /* Copy the final "$" */ *dst++ = *src++; size--; } *sizep = dst - buf; return buf; } static int git_path_check_crlf(const char *path, struct git_attr_check *check) { const char *value = check->value; if (ATTR_TRUE(value)) return CRLF_TEXT; else if (ATTR_FALSE(value)) return CRLF_BINARY; else if (ATTR_UNSET(value)) ; else if (!strcmp(value, "input")) return CRLF_INPUT; return CRLF_GUESS; } static struct convert_driver *git_path_check_convert(const char *path, struct git_attr_check *check) { const char *value = check->value; struct convert_driver *drv; if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value)) return NULL; for (drv = user_convert; drv; drv = drv->next) if (!strcmp(value, drv->name)) return drv; return NULL; } static int git_path_check_ident(const char *path, struct git_attr_check *check) { const char *value = check->value; return !!ATTR_TRUE(value); } char *convert_to_git(const char *path, const char *src, unsigned long *sizep) { struct git_attr_check check[3]; int crlf = CRLF_GUESS; int ident = 0; char *filter = NULL; char *buf, *buf2; setup_convert_check(check); if (!git_checkattr(path, ARRAY_SIZE(check), check)) { struct convert_driver *drv; crlf = git_path_check_crlf(path, check + 0); ident = git_path_check_ident(path, check + 1); drv = git_path_check_convert(path, check + 2); if (drv && drv->clean) filter = drv->clean; } buf = apply_filter(path, src, sizep, filter); buf2 = crlf_to_git(path, buf ? buf : src, sizep, crlf); if (buf2) { free(buf); buf = buf2; } buf2 = ident_to_git(path, buf ? buf : src, sizep, ident); if (buf2) { free(buf); buf = buf2; } return buf; } char *convert_to_working_tree(const char *path, const char *src, unsigned long *sizep) { struct git_attr_check check[3]; int crlf = CRLF_GUESS; int ident = 0; char *filter = NULL; char *buf, *buf2; setup_convert_check(check); if (!git_checkattr(path, ARRAY_SIZE(check), check)) { struct convert_driver *drv; crlf = git_path_check_crlf(path, check + 0); ident = git_path_check_ident(path, check + 1); drv = git_path_check_convert(path, check + 2); if (drv && drv->smudge) filter = drv->smudge; } buf = ident_to_worktree(path, src, sizep, ident); buf2 = crlf_to_worktree(path, buf ? buf : src, sizep, crlf); if (buf2) { free(buf); buf = buf2; } buf2 = apply_filter(path, buf ? buf : src, sizep, filter); if (buf2) { free(buf); buf = buf2; } return buf; } void *convert_sha1_file(const char *path, const unsigned char *sha1, unsigned int mode, enum object_type *type, unsigned long *size) { void *buffer = read_sha1_file(sha1, type, size); if (S_ISREG(mode) && buffer) { void *converted = convert_to_working_tree(path, buffer, size); if (converted) { free(buffer); buffer = converted; } } return buffer; }