Remove stat-based file identity tests.

Replace it with a simple pathname comparison instead.

The pathname check is not only portable (no need for any
compatibility helper functions), but we can do it much
earlier, and thus make the check much cheaper by avoiding
three extra system calls when it triggers (open/fstat/close).

And the pathname test seems to match all the cases anyway.

1 files changed, 19 insertions, 0 deletions

diff --git a/pre-process.c b/pre-process.c
index 950aea3..0a24f56 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -596,6 +596,23 @@ static const char *token_name_sequence(struct token *token, int endop, struct to
 	return buffer;
 }
 
+static int already_tokenized(const char *path)
+{
+	int i;
+	struct stream *s = input_streams;
+
+	for (i = input_stream_nr-1; i >= 0; i--, s++) {
+		if (s->constant != CONSTANT_FILE_YES)
+			continue;
+		if (strcmp(path, s->name))
+			continue;
+		if (!lookup_symbol(s->protect, NS_MACRO))
+			continue;
+		return 1;
+	}
+	return 0;
+}
+
 static int try_include(const char *path, int plen, const char *filename, int flen, struct token **where, const char **next_path)
 {
 	int fd;
@@ -607,6 +624,8 @@ static int try_include(const char *path, int plen, const char *filename, int fle
 		plen++;
 	}
 	memcpy(fullname+plen, filename, flen);
+	if (already_tokenized(fullname))
+		return 1;
 	fd = open(fullname, O_RDONLY);
 	if (fd >= 0) {
 		char * streamname = __alloc_bytes(plen + flen);