Add ".git/config" file parser

This is a first cut at a very simple parser for a git config file.

The format of the file is a simple ini-file like thing, with simple
variable/value pairs. You can (and should) make the variables have a
simple single-level scope, ie a valid file looks something like this:

	#
	# This is the config file, and
	# a '#' or ';' character indicates
	# a comment
	#

	; core variables
	[core]
		; Don't trust file modes
		filemode = false

	; Our diff algorithm
	[diff]
		external = "/usr/local/bin/gnu-diff -u"
		renames = true

which parses into three variables: "core.filemode" is associated with the
string "false", and "diff.external" gets the appropriate quoted value.

Right now we only react to one variable: "core.filemode" is a boolean that
decides if we should care about the 0100 (user-execute) bit of the stat
information. Even that is just a parsing demonstration - this doesn't
actually implement that st_mode compare logic itself.

Different programs can react to different config options, although they
should always fall back to calling "git_default_config()" on any config
option name that they don't recognize.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Makefile b/Makefile
index 0ca8e8d..c31af7b 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -158,7 +158,7 @@ LIB_OBJS = \
        object.o pack-check.o patch-delta.o path.o pkt-line.o \
        quote.o read-cache.o refs.o run-command.o \
        server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
-       tag.o tree.o usage.o $(DIFF_OBJS)
+       tag.o tree.o usage.o config.o $(DIFF_OBJS)
 
 LIBS = $(LIB_FILE)
 LIBS += -lz

diff --git a/cache.h b/cache.h
index 5987d4c..0571282 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -178,6 +178,8 @@ extern int hold_index_file_for_update(struct cache_file *, const char *path);
 extern int commit_index_file(struct cache_file *);
 extern void rollback_index_file(struct cache_file *);
 
+extern int trust_executable_bit;
+
 #define MTIME_CHANGED  0x0001
 #define CTIME_CHANGED  0x0002
 #define OWNER_CHANGED  0x0004
@@ -372,4 +374,10 @@ extern int gitfakemunmap(void *start, size_t length);
 
 #endif
 
+typedef int (*config_fn_t)(const char *, const char *);
+extern int git_default_config(const char *, const char *);
+extern int git_config(config_fn_t fn);
+extern int git_config_int(const char *, const char *);
+extern int git_config_bool(const char *, const char *);
+
 #endif /* CACHE_H */

diff --git a/config.c b/config.c
new file mode 100644 (file)
index 0000000..f3c4fa4
--- /dev/null
+++ b/config.c
@@ -0,0 +1,222 @@
+#include <ctype.h>
+
+#include "cache.h"
+
+#define MAXNAME (256)
+
+static FILE *config_file;
+static int config_linenr;
+static int get_next_char(void)
+{
+       int c;
+       FILE *f;
+
+       c = '\n';
+       if ((f = config_file) != NULL) {
+               c = fgetc(f);
+               if (c == '\n')
+                       config_linenr++;
+               if (c == EOF) {
+                       config_file = NULL;
+                       c = '\n';
+               }
+       }
+       return c;
+}
+
+static char *parse_value(void)
+{
+       static char value[1024];
+       int quote = 0, comment = 0, len = 0, space = 0;
+
+       for (;;) {
+               int c = get_next_char();
+               if (len >= sizeof(value))
+                       return NULL;
+               if (c == '\n') {
+                       if (quote)
+                               return NULL;
+                       value[len] = 0;
+                       return value;
+               }
+               if (comment)
+                       continue;
+               if (isspace(c) && !quote) {
+                       space = 1;
+                       continue;
+               }
+               if (space) {
+                       if (len)
+                               value[len++] = ' ';
+                       space = 0;
+               }
+               if (c == '\\') {
+                       c = get_next_char();
+                       switch (c) {
+                       case '\n':
+                               continue;
+                       case 't':
+                               c = '\t';
+                               break;
+                       case 'b':
+                               c = '\b';
+                               break;
+                       case 'n':
+                               c = '\n';
+                               break;
+                       return NULL;
+                       }
+                       value[len++] = c;
+                       continue;
+               }
+               if (c == '"') {
+                       quote = 1-quote;
+                       continue;
+               }
+               if (!quote) {
+                       if (c == ';' || c == '#') {
+                               comment = 1;
+                               continue;
+                       }
+               }
+               value[len++] = c;
+       }
+}
+
+static int get_value(config_fn_t fn, char *name, unsigned int len)
+{
+       int c;
+       char *value;
+
+       /* Get the full name */
+       for (;;) {
+               c = get_next_char();
+               if (c == EOF)
+                       break;
+               if (!isalnum(c))
+                       break;
+               name[len++] = tolower(c);
+               if (len >= MAXNAME)
+                       return -1;
+       }
+       name[len] = 0;
+       while (c == ' ' || c == '\t')
+               c = get_next_char();
+
+       value = NULL;
+       if (c != '\n') {
+               if (c != '=')
+                       return -1;
+               value = parse_value();
+               if (!value)
+                       return -1;
+       }
+       return fn(name, value);
+}
+
+static int get_base_var(char *name)
+{
+       int baselen = 0;
+
+       for (;;) {
+               int c = get_next_char();
+               if (c == EOF)
+                       return -1;
+               if (c == ']')
+                       return baselen;
+               if (!isalnum(c))
+                       return -1;
+               if (baselen > MAXNAME / 2)
+                       return -1;
+               name[baselen++] = tolower(c);
+       }
+}
+
+static int git_parse_file(config_fn_t fn)
+{
+       int comment = 0;
+       int baselen = 0;
+       static char var[MAXNAME];
+
+       for (;;) {
+               int c = get_next_char();
+               if (c == '\n') {
+                       /* EOF? */
+                       if (!config_file)
+                               return 0;
+                       comment = 0;
+                       continue;
+               }
+               if (comment || isspace(c))
+                       continue;
+               if (c == '#' || c == ';') {
+                       comment = 1;
+                       continue;
+               }
+               if (c == '[') {
+                       baselen = get_base_var(var);
+                       if (baselen <= 0)
+                               break;
+                       var[baselen++] = '.';
+                       var[baselen] = 0;
+                       continue;
+               }
+               if (!isalpha(c))
+                       break;
+               var[baselen] = c;
+               if (get_value(fn, var, baselen+1) < 0)
+                       break;
+       }
+       die("bad config file line %d", config_linenr);
+}
+
+int git_config_int(const char *name, const char *value)
+{
+       if (value && *value) {
+               char *end;
+               int val = strtol(value, &end, 0);
+               if (!*end)
+                       return val;
+       }
+       die("bad config value for '%s'", name);
+}
+
+int git_config_bool(const char *name, const char *value)
+{
+       if (!value)
+               return 1;
+       if (!*value)
+               return 0;
+       if (!strcasecmp(value, "true"))
+               return 1;
+       if (!strcasecmp(value, "false"))
+               return 0;
+       return git_config_int(name, value) != 0;
+}
+
+int git_default_config(const char *var, const char *value)
+{
+       /* This needs a better name */
+       if (!strcmp(var, "core.filemode")) {
+               trust_executable_bit = git_config_bool(var, value);
+               return 0;
+       }
+
+       /* Add other config variables here.. */
+       return 0;
+}
+
+int git_config(config_fn_t fn)
+{
+       int ret;
+       FILE *f = fopen(git_path("config"), "r");
+
+       ret = -1;
+       if (f) {
+               config_file = f;
+               config_linenr = 1;
+               ret = git_parse_file(fn);
+               fclose(f);
+       }
+       return ret;
+}

diff --git a/diff-files.c b/diff-files.c
index 5e59832..96d2c7f 100644 (file)
--- a/diff-files.c
+++ b/diff-files.c
@@ -38,6 +38,7 @@ int main(int argc, const char **argv)
        const char *prefix = setup_git_directory();
        int entries, i;
 
+       git_config(git_default_config);
        diff_setup(&diff_options);
        while (1 < argc && argv[1][0] == '-') {
                if (!strcmp(argv[1], "-q"))

diff --git a/diff-tree.c b/diff-tree.c
index b2d74eb..2203fa5 100644 (file)
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -408,6 +408,7 @@ int main(int argc, const char **argv)
        unsigned char sha1[2][20];
        const char *prefix = setup_git_directory();
 
+       git_config(git_default_config);
        nr_sha1 = 0;
        diff_setup(&diff_options);
 

diff --git a/read-cache.c b/read-cache.c
index d2aebdd..c7f3b26 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -5,6 +5,7 @@
  */
 #include "cache.h"
 
+int trust_executable_bit = 1;
 struct cache_entry **active_cache = NULL;
 unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;