From: Joel Rosdahl <joel@rosdahl.net>
Date: Thu, 4 Mar 2010 19:30:27 +0000 (+0100)
Subject: Fix caching of empty source files in direct mode
X-Git-Tag: v3.0pre1~91
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=baf2ff5d6b882052d558815ff5d701ab65b3fb6f;p=thirdparty%2Fccache.git

Fix caching of empty source files in direct mode
---

diff --git a/comments.c b/comments.c
index 117395447..771b38b88 100644
--- a/comments.c
+++ b/comments.c
@@ -128,6 +128,10 @@ int hash_file_ignoring_comments(struct mdfour *hash, const char *path)
 		close(fd);
 		return 0;
 	}
+	if (st.st_size == 0) {
+		close(fd);
+		return 1;
+	}
 	data = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
 	if (data == (void *)-1) {
diff --git a/test.sh b/test.sh
index eda5443be..cded5cc3d 100755
--- a/test.sh
+++ b/test.sh
@@ -717,6 +717,20 @@ EOF
     checkstat 'cache hit (preprocessed)' 0
     checkstat 'cache miss' 2
 
+    ##################################################################
+    # Check that it's possible to compile and cache an empty source code file.
+    testname="empty source file"
+    $CCACHE -Cz >/dev/null
+    cp /dev/null empty.c
+    $CCACHE_COMPILE -c empty.c
+    checkstat 'cache hit (direct)' 0
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+    $CCACHE_COMPILE -c empty.c
+    checkstat 'cache hit (direct)' 1
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+
     ##################################################################
     # Reset things.
     CCACHE_NODIRECT=1