From: Andrew Tridgell <tridge@samba.org>
Date: Tue, 26 Mar 2002 22:25:14 +0000 (+0100)
Subject: ccache is now pretty well ready for use
X-Git-Tag: v1.0~48
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11628d7f7bd4f5f134e95877d835ae6fa68b8a6f;p=thirdparty%2Fccache.git

ccache is now pretty well ready for use
---

diff --git a/ccache.c b/ccache.c
index a4a1010b1..d0ed0193b 100644
--- a/ccache.c
+++ b/ccache.c
@@ -57,7 +57,7 @@ static void stabs_hash(const char *fname)
 {
 	FILE *f;
 	char *s;
-	char line[1024];
+	static char line[102400];
 
 	line[sizeof(line)-2] = 0;
 
@@ -93,6 +93,7 @@ static void find_hash(ARGS *args)
 	char *path_stdout, *path_stderr, *path_status;
 	char *hash_dir;
 	char *s;
+	struct stat st;
 
 	hash_start();
 
@@ -101,6 +102,15 @@ static void find_hash(ARGS *args)
 		hash_string(args->argv[i]);
 	}
 
+	/* the compiler driver size and date. This is a simple minded way
+	   to try and detect compiler upgrades. It is not 100% reliable */
+	if (stat(args->argv[0], &st) != 0) {
+		cc_log("Couldn't stat the compiler!?\n");
+		failed();
+	}
+	hash_int(st.st_size);
+	hash_int(st.st_mtime);
+
 	/* now the run */
 	x_asprintf(&path_stdout, "%s/tmp.stdout.%d", cache_dir, getpid());
 	x_asprintf(&path_stderr, "%s/tmp.stderr.%d", cache_dir, getpid());
@@ -110,6 +120,11 @@ static void find_hash(ARGS *args)
 	execute(args->argv, path_stdout, path_stderr, path_status);
 	args->argc--;
 
+	/* if the compilation is with -g then we have to inlcude the whole of the
+	   preprocessor output, which means we are sensitive to line number
+	   information. Otherwise we can discard line number info, which makes
+	   us less sensitive to reformatting changes 
+	*/
 	if (found_debug) {
 		hash_file(path_stdout);
 	} else {
@@ -127,7 +142,10 @@ static void find_hash(ARGS *args)
 
 	s = hash_result();
 	x_asprintf(&hash_dir, "%s/%c", cache_dir, *s);
-	mkdir(hash_dir, 0755);
+	if (create_dir(hash_dir) != 0) {
+		cc_log("failed to create %s\n", cache_dir);
+		failed();
+	}
 	x_asprintf(&hashname, "%s/%s", hash_dir, s+1);
 	free(hash_dir);
 }
@@ -168,9 +186,10 @@ static void from_cache(int first)
 	unlink(output_file);
 	ret = link(hashname, output_file);
 	if (ret == -1 && errno != ENOENT) {
-		/* copy it instead */
-		cc_log("copy not implemented\n");
-		failed();
+		ret = symlink(hashname, output_file);
+	}
+	if (ret == 0) {
+		utime(output_file, NULL);
 	}
 
 	/* send the stderr */
@@ -217,8 +236,14 @@ static char *find_compiler(const char *argv0)
 		base = argv0;
 	}
 
-	path = getenv("PATH");
-	if (!path) return NULL;
+	path = getenv("CCACHE_PATH");
+	if (!path) {
+		path = getenv("PATH");
+	}
+	if (!path) {
+		cc_log("no PATH variable!?\n");
+		failed();
+	}
 
 	path = x_strdup(path);
 	
@@ -380,8 +405,8 @@ static void ccache(int argc, char *argv[])
 
 int main(int argc, char *argv[])
 {
-	if (mkdir(cache_dir, 0755) != 0 && errno != EEXIST) {
-		fprintf(stderr,"Failed to create %s (%s)\n", 
+	if (create_dir(cache_dir) != 0) {
+		fprintf(stderr,"ccache: failed to create %s (%s)\n", 
 			cache_dir, strerror(errno));
 		exit(1);
 	}
diff --git a/ccache.h b/ccache.h
index 6c633312c..093e11bea 100644
--- a/ccache.h
+++ b/ccache.h
@@ -11,6 +11,7 @@
 #include <fcntl.h>
 #include <string.h>
 #include <ctype.h>
+#include <utime.h>
 #include <stdarg.h>
 
 #define STATUS_NOTFOUND 3
@@ -27,6 +28,7 @@ typedef unsigned uint32;
 
 void hash_start(void);
 void hash_string(const char *s);
+void hash_int(int x);
 void hash_file(const char *fname);
 char *hash_result(void);
 
@@ -36,6 +38,8 @@ void oom(const char *msg);
 
 void copy_fd(int fd_in, int fd_out);
 
+int create_dir(const char *dir);
+
 void execute(char **argv, 
 	     const char *path_stdout,
 	     const char *path_stderr,
diff --git a/hash.c b/hash.c
index 125945ff4..ebcd8a7eb 100644
--- a/hash.c
+++ b/hash.c
@@ -18,6 +18,11 @@ void hash_string(const char *s)
 	mdfour_update(&md, s, strlen(s));
 }
 
+void hash_int(int x)
+{
+	mdfour_update(&md, (unsigned char *)&x, sizeof(x));
+}
+
 /* add contents of a file to the hash */
 void hash_file(const char *fname)
 {
diff --git a/util.c b/util.c
index 52cdd0120..98f48617a 100644
--- a/util.c
+++ b/util.c
@@ -41,3 +41,19 @@ void oom(const char *msg)
 	cc_log("Out of memory: %s\n", msg);
 	exit(1);
 }
+
+int create_dir(const char *dir)
+{
+	struct stat st;
+	if (stat(dir, &st) == 0) {
+		if (S_ISDIR(st.st_mode)) {
+			return 0;
+		}
+		errno = ENOTDIR;
+		return 1;
+	}
+	if (mkdir(dir, 0777) != 0) {
+		return 1;
+	}
+	return 0;
+}