diff options
Diffstat (limited to 'attr.c')
| -rw-r--r-- | attr.c | 644 |
1 files changed, 644 insertions, 0 deletions
@@ -0,0 +1,644 @@ +#include "cache.h" +#include "attr.h" + +const char git_attr__true[] = "(builtin)true"; +const char git_attr__false[] = "\0(builtin)false"; +static const char git_attr__unknown[] = "(builtin)unknown"; +#define ATTR__TRUE git_attr__true +#define ATTR__FALSE git_attr__false +#define ATTR__UNSET NULL +#define ATTR__UNKNOWN git_attr__unknown + +/* + * The basic design decision here is that we are not going to have + * insanely large number of attributes. + * + * This is a randomly chosen prime. + */ +#define HASHSIZE 257 + +#ifndef DEBUG_ATTR +#define DEBUG_ATTR 0 +#endif + +struct git_attr { + struct git_attr *next; + unsigned h; + int attr_nr; + char name[FLEX_ARRAY]; +}; +static int attr_nr; + +static struct git_attr_check *check_all_attr; +static struct git_attr *(git_attr_hash[HASHSIZE]); + +static unsigned hash_name(const char *name, int namelen) +{ + unsigned val = 0; + unsigned char c; + + while (namelen--) { + c = *name++; + val = ((val << 7) | (val >> 22)) ^ c; + } + return val; +} + +static int invalid_attr_name(const char *name, int namelen) +{ + /* + * Attribute name cannot begin with '-' and from + * [-A-Za-z0-9_.]. We'd specifically exclude '=' for now, + * as we might later want to allow non-binary value for + * attributes, e.g. "*.svg merge=special-merge-program-for-svg" + */ + if (*name == '-') + return -1; + while (namelen--) { + char ch = *name++; + if (! (ch == '-' || ch == '.' || ch == '_' || + ('0' <= ch && ch <= '9') || + ('a' <= ch && ch <= 'z') || + ('A' <= ch && ch <= 'Z')) ) + return -1; + } + return 0; +} + +struct git_attr *git_attr(const char *name, int len) +{ + unsigned hval = hash_name(name, len); + unsigned pos = hval % HASHSIZE; + struct git_attr *a; + + for (a = git_attr_hash[pos]; a; a = a->next) { + if (a->h == hval && + !memcmp(a->name, name, len) && !a->name[len]) + return a; + } + + if (invalid_attr_name(name, len)) + return NULL; + + a = xmalloc(sizeof(*a) + len + 1); + memcpy(a->name, name, len); + a->name[len] = 0; + a->h = hval; + a->next = git_attr_hash[pos]; + a->attr_nr = attr_nr++; + git_attr_hash[pos] = a; + + check_all_attr = xrealloc(check_all_attr, + sizeof(*check_all_attr) * attr_nr); + check_all_attr[a->attr_nr].attr = a; + check_all_attr[a->attr_nr].value = ATTR__UNKNOWN; + return a; +} + +/* + * .gitattributes file is one line per record, each of which is + * + * (1) glob pattern. + * (2) whitespace + * (3) whitespace separated list of attribute names, each of which + * could be prefixed with '-' to mean "set to false", '!' to mean + * "unset". + */ + +/* What does a matched pattern decide? */ +struct attr_state { + struct git_attr *attr; + const char *setto; +}; + +struct match_attr { + union { + char *pattern; + struct git_attr *attr; + } u; + char is_macro; + unsigned num_attr; + struct attr_state state[FLEX_ARRAY]; +}; + +static const char blank[] = " \t\r\n"; + +static const char *parse_attr(const char *src, int lineno, const char *cp, + int *num_attr, struct match_attr *res) +{ + const char *ep, *equals; + int len; + + ep = cp + strcspn(cp, blank); + equals = strchr(cp, '='); + if (equals && ep < equals) + equals = NULL; + if (equals) + len = equals - cp; + else + len = ep - cp; + if (!res) { + if (*cp == '-' || *cp == '!') { + cp++; + len--; + } + if (invalid_attr_name(cp, len)) { + fprintf(stderr, + "%.*s is not a valid attribute name: %s:%d\n", + len, cp, src, lineno); + return NULL; + } + } else { + struct attr_state *e; + + e = &(res->state[*num_attr]); + if (*cp == '-' || *cp == '!') { + e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET; + cp++; + len--; + } + else if (!equals) + e->setto = ATTR__TRUE; + else { + e->setto = xmemdupz(equals + 1, ep - equals - 1); + } + e->attr = git_attr(cp, len); + } + (*num_attr)++; + return ep + strspn(ep, blank); +} + +static struct match_attr *parse_attr_line(const char *line, const char *src, + int lineno, int macro_ok) +{ + int namelen; + int num_attr; + const char *cp, *name; + struct match_attr *res = NULL; + int pass; + int is_macro; + + cp = line + strspn(line, blank); + if (!*cp || *cp == '#') + return NULL; + name = cp; + namelen = strcspn(name, blank); + if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen && + !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) { + if (!macro_ok) { + fprintf(stderr, "%s not allowed: %s:%d\n", + name, src, lineno); + return NULL; + } + is_macro = 1; + name += strlen(ATTRIBUTE_MACRO_PREFIX); + name += strspn(name, blank); + namelen = strcspn(name, blank); + if (invalid_attr_name(name, namelen)) { + fprintf(stderr, + "%.*s is not a valid attribute name: %s:%d\n", + namelen, name, src, lineno); + return NULL; + } + } + else + is_macro = 0; + + for (pass = 0; pass < 2; pass++) { + /* pass 0 counts and allocates, pass 1 fills */ + num_attr = 0; + cp = name + namelen; + cp = cp + strspn(cp, blank); + while (*cp) { + cp = parse_attr(src, lineno, cp, &num_attr, res); + if (!cp) + return NULL; + } + if (pass) + break; + res = xcalloc(1, + sizeof(*res) + + sizeof(struct attr_state) * num_attr + + (is_macro ? 0 : namelen + 1)); + if (is_macro) + res->u.attr = git_attr(name, namelen); + else { + res->u.pattern = (char*)&(res->state[num_attr]); + memcpy(res->u.pattern, name, namelen); + res->u.pattern[namelen] = 0; + } + res->is_macro = is_macro; + res->num_attr = num_attr; + } + return res; +} + +/* + * Like info/exclude and .gitignore, the attribute information can + * come from many places. + * + * (1) .gitattribute file of the same directory; + * (2) .gitattribute file of the parent directory if (1) does not have + * any match; this goes recursively upwards, just like .gitignore. + * (3) $GIT_DIR/info/attributes, which overrides both of the above. + * + * In the same file, later entries override the earlier match, so in the + * global list, we would have entries from info/attributes the earliest + * (reading the file from top to bottom), .gitattribute of the root + * directory (again, reading the file from top to bottom) down to the + * current directory, and then scan the list backwards to find the first match. + * This is exactly the same as what excluded() does in dir.c to deal with + * .gitignore + */ + +static struct attr_stack { + struct attr_stack *prev; + char *origin; + unsigned num_matches; + unsigned alloc; + struct match_attr **attrs; +} *attr_stack; + +static void free_attr_elem(struct attr_stack *e) +{ + int i; + free(e->origin); + for (i = 0; i < e->num_matches; i++) { + struct match_attr *a = e->attrs[i]; + int j; + for (j = 0; j < a->num_attr; j++) { + const char *setto = a->state[j].setto; + if (setto == ATTR__TRUE || + setto == ATTR__FALSE || + setto == ATTR__UNSET || + setto == ATTR__UNKNOWN) + ; + else + free((char*) setto); + } + free(a); + } + free(e); +} + +static const char *builtin_attr[] = { + "[attr]binary -diff -crlf", + NULL, +}; + +static void handle_attr_line(struct attr_stack *res, + const char *line, + const char *src, + int lineno, + int macro_ok) +{ + struct match_attr *a; + + a = parse_attr_line(line, src, lineno, macro_ok); + if (!a) + return; + if (res->alloc <= res->num_matches) { + res->alloc = alloc_nr(res->num_matches); + res->attrs = xrealloc(res->attrs, + sizeof(struct match_attr *) * + res->alloc); + } + res->attrs[res->num_matches++] = a; +} + +static struct attr_stack *read_attr_from_array(const char **list) +{ + struct attr_stack *res; + const char *line; + int lineno = 0; + + res = xcalloc(1, sizeof(*res)); + while ((line = *(list++)) != NULL) + handle_attr_line(res, line, "[builtin]", ++lineno, 1); + return res; +} + +static struct attr_stack *read_attr_from_file(const char *path, int macro_ok) +{ + FILE *fp = fopen(path, "r"); + struct attr_stack *res; + char buf[2048]; + int lineno = 0; + + if (!fp) + return NULL; + res = xcalloc(1, sizeof(*res)); + while (fgets(buf, sizeof(buf), fp)) + handle_attr_line(res, buf, path, ++lineno, macro_ok); + fclose(fp); + return res; +} + +static void *read_index_data(const char *path) +{ + int pos, len; + unsigned long sz; + enum object_type type; + void *data; + + len = strlen(path); + pos = cache_name_pos(path, len); + if (pos < 0) { + /* + * We might be in the middle of a merge, in which + * case we would read stage #2 (ours). + */ + int i; + for (i = -pos - 1; + (pos < 0 && i < active_nr && + !strcmp(active_cache[i]->name, path)); + i++) + if (ce_stage(active_cache[i]) == 2) + pos = i; + } + if (pos < 0) + return NULL; + data = read_sha1_file(active_cache[pos]->sha1, &type, &sz); + if (!data || type != OBJ_BLOB) { + free(data); + return NULL; + } + return data; +} + +static struct attr_stack *read_attr(const char *path, int macro_ok) +{ + struct attr_stack *res; + char *buf, *sp; + int lineno = 0; + + res = read_attr_from_file(path, macro_ok); + if (res) + return res; + + res = xcalloc(1, sizeof(*res)); + + /* + * There is no checked out .gitattributes file there, but + * we might have it in the index. We allow operation in a + * sparsely checked out work tree, so read from it. + */ + buf = read_index_data(path); + if (!buf) + return res; + + for (sp = buf; *sp; ) { + char *ep; + int more; + for (ep = sp; *ep && *ep != '\n'; ep++) + ; + more = (*ep == '\n'); + *ep = '\0'; + handle_attr_line(res, sp, path, ++lineno, macro_ok); + sp = ep + more; + } + free(buf); + return res; +} + +#if DEBUG_ATTR +static void debug_info(const char *what, struct attr_stack *elem) +{ + fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()"); +} +static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v) +{ + const char *value = v; + + if (ATTR_TRUE(value)) + value = "set"; + else if (ATTR_FALSE(value)) + value = "unset"; + else if (ATTR_UNSET(value)) + value = "unspecified"; + + fprintf(stderr, "%s: %s => %s (%s)\n", + what, attr->name, (char *) value, match); +} +#define debug_push(a) debug_info("push", (a)) +#define debug_pop(a) debug_info("pop", (a)) +#else +#define debug_push(a) do { ; } while (0) +#define debug_pop(a) do { ; } while (0) +#define debug_set(a,b,c,d) do { ; } while (0) +#endif + +static void bootstrap_attr_stack(void) +{ + if (!attr_stack) { + struct attr_stack *elem; + + elem = read_attr_from_array(builtin_attr); + elem->origin = NULL; + elem->prev = attr_stack; + attr_stack = elem; + + if (!is_bare_repository()) { + elem = read_attr(GITATTRIBUTES_FILE, 1); + elem->origin = strdup(""); + elem->prev = attr_stack; + attr_stack = elem; + debug_push(elem); + } + + elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1); + if (!elem) + elem = xcalloc(1, sizeof(*elem)); + elem->origin = NULL; + elem->prev = attr_stack; + attr_stack = elem; + } +} + +static void prepare_attr_stack(const char *path, int dirlen) +{ + struct attr_stack *elem, *info; + int len; + struct strbuf pathbuf; + + strbuf_init(&pathbuf, dirlen+2+strlen(GITATTRIBUTES_FILE)); + + /* + * At the bottom of the attribute stack is the built-in + * set of attribute definitions. Then, contents from + * .gitattribute files from directories closer to the + * root to the ones in deeper directories are pushed + * to the stack. Finally, at the very top of the stack + * we always keep the contents of $GIT_DIR/info/attributes. + * + * When checking, we use entries from near the top of the + * stack, preferring $GIT_DIR/info/attributes, then + * .gitattributes in deeper directories to shallower ones, + * and finally use the built-in set as the default. + */ + if (!attr_stack) + bootstrap_attr_stack(); + + /* + * Pop the "info" one that is always at the top of the stack. + */ + info = attr_stack; + attr_stack = info->prev; + + /* + * Pop the ones from directories that are not the prefix of + * the path we are checking. + */ + while (attr_stack && attr_stack->origin) { + int namelen = strlen(attr_stack->origin); + + elem = attr_stack; + if (namelen <= dirlen && + !strncmp(elem->origin, path, namelen)) + break; + + debug_pop(elem); + attr_stack = elem->prev; + free_attr_elem(elem); + } + + /* + * Read from parent directories and push them down + */ + if (!is_bare_repository()) { + while (1) { + char *cp; + + len = strlen(attr_stack->origin); + if (dirlen <= len) + break; + strbuf_reset(&pathbuf); + strbuf_add(&pathbuf, path, dirlen); + strbuf_addch(&pathbuf, '/'); + cp = strchr(pathbuf.buf + len + 1, '/'); + strcpy(cp + 1, GITATTRIBUTES_FILE); + elem = read_attr(pathbuf.buf, 0); + *cp = '\0'; + elem->origin = strdup(pathbuf.buf); + elem->prev = attr_stack; + attr_stack = elem; + debug_push(elem); + } + } + + /* + * Finally push the "info" one at the top of the stack. + */ + info->prev = attr_stack; + attr_stack = info; +} + +static int path_matches(const char *pathname, int pathlen, + const char *pattern, + const char *base, int baselen) +{ + if (!strchr(pattern, '/')) { + /* match basename */ + const char *basename = strrchr(pathname, '/'); + basename = basename ? basename + 1 : pathname; + return (fnmatch(pattern, basename, 0) == 0); + } + /* + * match with FNM_PATHNAME; the pattern has base implicitly + * in front of it. + */ + if (*pattern == '/') + pattern++; + if (pathlen < baselen || + (baselen && pathname[baselen] != '/') || + strncmp(pathname, base, baselen)) + return 0; + if (baselen != 0) + baselen++; + return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0; +} + +static int fill_one(const char *what, struct match_attr *a, int rem) +{ + struct git_attr_check *check = check_all_attr; + int i; + + for (i = 0; 0 < rem && i < a->num_attr; i++) { + struct git_attr *attr = a->state[i].attr; + const char **n = &(check[attr->attr_nr].value); + const char *v = a->state[i].setto; + + if (*n == ATTR__UNKNOWN) { + debug_set(what, a->u.pattern, attr, v); + *n = v; + rem--; + } + } + return rem; +} + +static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem) +{ + int i; + const char *base = stk->origin ? stk->origin : ""; + + for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) { + struct match_attr *a = stk->attrs[i]; + if (a->is_macro) + continue; + if (path_matches(path, pathlen, + a->u.pattern, base, strlen(base))) + rem = fill_one("fill", a, rem); + } + return rem; +} + +static int macroexpand(struct attr_stack *stk, int rem) +{ + int i; + struct git_attr_check *check = check_all_attr; + + for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) { + struct match_attr *a = stk->attrs[i]; + if (!a->is_macro) + continue; + if (check[a->u.attr->attr_nr].value != ATTR__TRUE) + continue; + rem = fill_one("expand", a, rem); + } + return rem; +} + +int git_checkattr(const char *path, int num, struct git_attr_check *check) +{ + struct attr_stack *stk; + const char *cp; + int dirlen, pathlen, i, rem; + + bootstrap_attr_stack(); + for (i = 0; i < attr_nr; i++) + check_all_attr[i].value = ATTR__UNKNOWN; + + pathlen = strlen(path); + cp = strrchr(path, '/'); + if (!cp) + dirlen = 0; + else + dirlen = cp - path; + prepare_attr_stack(path, dirlen); + rem = attr_nr; + for (stk = attr_stack; 0 < rem && stk; stk = stk->prev) + rem = fill(path, pathlen, stk, rem); + + for (stk = attr_stack; 0 < rem && stk; stk = stk->prev) + rem = macroexpand(stk, rem); + + for (i = 0; i < num; i++) { + const char *value = check_all_attr[check[i].attr->attr_nr].value; + if (value == ATTR__UNKNOWN) + value = ATTR__UNSET; + check[i].value = value; + } + + return 0; +} |