From: Jørgen P. Tjernø <jorgen@valvesoftware.com>
Date: Sat, 8 Jun 2013 01:43:18 +0000 (-0700)
Subject: Skip dependency filename options for object hash.
X-Git-Tag: v3.2~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cea77ffd4c15040e2e677677f20347ea77d82407;p=thirdparty%2Fccache.git

Skip dependency filename options for object hash.

The filename of a dependency file doesn't have any bearing on the result, so
using it to calculate object hashes gives incorrect results.

This skips the <file> part of:
  -Wp,-MD,<file>
  -Wp,-MMD,<file>
  -MF<file>
  -MF <file>

Also tests for this functionality.

Fixes issue jrosdahl#28.
---

diff --git a/ccache.c b/ccache.c
index 77590359c..0d6df5452 100644
--- a/ccache.c
+++ b/ccache.c
@@ -1152,6 +1152,36 @@ calculate_object_hash(struct args *args, struct mdfour *hash, int direct_mode)
 			}
 		}
 
+		/* If we're generating dependencies, we make sure to skip the
+		 * filename of the dependency file, since it doesn't impact the
+		 * output.
+		 */
+		if (generating_dependencies) {
+			if (str_startswith(args->argv[i], "-Wp,")) {
+				if (str_startswith(args->argv[i], "-Wp,-MD,")
+						&& !strchr(args->argv[i] + 8, ',')) {
+					hash_string_length(hash, args->argv[i], 8);
+					continue;
+				} else if (str_startswith(args->argv[i], "-Wp,-MMD,")
+						&& !strchr(args->argv[i] + 9, ',')) {
+					hash_string_length(hash, args->argv[i], 9);
+					continue;
+				}
+			} else if (str_startswith(args->argv[i], "-MF")) {
+				bool separate_argument = (strlen(args->argv[i]) == 3);
+
+				/* In either case, hash the "-MF" part. */
+				hash_string_length(hash, args->argv[i], 3);
+
+				if (separate_argument) {
+					/* Next argument is dependency name, so
+					 * skip it. */
+					i++;
+				}
+				continue;
+			}
+		}
+
 		p = NULL;
 		if (str_startswith(args->argv[i], "-specs=")) {
 			p = args->argv[i] + 7;
diff --git a/ccache.h b/ccache.h
index 00aec468a..48812df05 100644
--- a/ccache.h
+++ b/ccache.h
@@ -101,6 +101,7 @@ void hash_result_as_bytes(struct mdfour *md, unsigned char *out);
 bool hash_equal(struct mdfour *md1, struct mdfour *md2);
 void hash_delimiter(struct mdfour *md, const char *type);
 void hash_string(struct mdfour *md, const char *s);
+void hash_string_length(struct mdfour *md, const char *s, int length);
 void hash_int(struct mdfour *md, int x);
 bool hash_fd(struct mdfour *md, int fd);
 bool hash_file(struct mdfour *md, const char *fname);
diff --git a/hash.c b/hash.c
index b6a9e5ea2..80beed23a 100644
--- a/hash.c
+++ b/hash.c
@@ -80,7 +80,13 @@ hash_delimiter(struct mdfour *md, const char *type)
 void
 hash_string(struct mdfour *md, const char *s)
 {
-	hash_buffer(md, s, strlen(s));
+	hash_string_length(md, s, strlen(s));
+}
+
+void
+hash_string_length(struct mdfour *md, const char *s, int length)
+{
+        hash_buffer(md, s, length);
 }
 
 void
diff --git a/test.sh b/test.sh
index 95409ff44..efabac2c0 100755
--- a/test.sh
+++ b/test.sh
@@ -841,6 +841,15 @@ EOF
 
     rm -f other.d
 
+    $CCACHE $COMPILER -c -Wp,-MD,different_name.d test.c
+    checkstat 'cache hit (direct)' 2
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+    checkfile different_name.d "$expected_d_content"
+    compare_file reference_test.o test.o
+
+    rm -f different_name.d
+
     ##################################################################
     # Check that -Wp,-MMD,file.d works.
     testname="-Wp,-MMD"
@@ -865,6 +874,15 @@ EOF
 
     rm -f other.d
 
+    $CCACHE $COMPILER -c -Wp,-MMD,different_name.d test.c
+    checkstat 'cache hit (direct)' 2
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+    checkfile different_name.d "$expected_mmd_d_content"
+    compare_file reference_test.o test.o
+
+    rm -f different_name.d
+
     ##################################################################
     # Test some header modifications to get multiple objects in the manifest.
     testname="several objects"
@@ -963,6 +981,24 @@ EOF
     checkfile other.d "$expected_d_content"
     compare_file reference_test.o test.o
 
+    $CCACHE $COMPILER -c -MD -MF different_name.d test.c
+    checkstat 'cache hit (direct)' 2
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+    checkfile different_name.d "$expected_d_content"
+    compare_file reference_test.o test.o
+
+    rm -f different_name.d
+
+    $CCACHE $COMPILER -c -MD -MFthird_name.d test.c
+    checkstat 'cache hit (direct)' 3
+    checkstat 'cache hit (preprocessed)' 0
+    checkstat 'cache miss' 1
+    checkfile third_name.d "$expected_d_content"
+    compare_file reference_test.o test.o
+
+    rm -f third_name.d
+
     ##################################################################
     # Check that a missing .d file in the cache is handled correctly.
     testname="missing dependency file"