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.

1 files changed, 1 insertions, 0 deletions

diff --git a/ccache.h b/ccache.h
index 00aec468..48812df0 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);