From: Anders Björklund <anders@itension.se>
Date: Sun, 26 Jun 2016 21:03:59 +0000 (+0200)
Subject: Work around preprocessor bugs in gcc version 6
X-Git-Tag: v3.2.6~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a21800173c6d981a3b2d40c57934335a0b08f69f;p=thirdparty%2Fccache.git

Work around preprocessor bugs in gcc version 6

Before hashing the output of the preprocessor (gcc -E):
- Ignore extra line `# 31 "<command-line>"` completely.
- Replace `# 32 "<command-line>" 2` with the regular # 1.
For some reason this only happens with gcc without macros.

Closes #96
---

diff --git a/ccache.c b/ccache.c
index b61fac4cb..1197e618e 100644
--- a/ccache.c
+++ b/ccache.c
@@ -750,6 +750,28 @@ process_preprocessed_file(struct mdfour *hash, const char *path)
 		    && (q == data || q[-1] == '\n')) {
 			char *path;
 
+			/* Workarounds for preprocessor linemarker bugs in GCC version 6 */
+			if (q[2] == '3') {
+				if (str_startswith(q, "# 31 \"<command-line>\"\n")) {
+					/* Bogus extra line with #31, after the regular #1:
+					   Ignore the whole line, and continue parsing */
+					while (q < end && *q != '\n') {
+						q++;
+					}
+					p = q;
+					continue;
+				} else if (str_startswith(q, "# 32 \"<command-line>\" 2\n")) {
+					/* Bogus wrong line with #32, instead of regular #1:
+					   Replace the line number with the usual one */
+					hash_buffer(hash, p, q - p);
+					q += 1;
+					q[0] = '#';
+					q[1] = ' ';
+					q[2] = '1';
+					p = q;
+				}
+			}
+
 			while (q < end && *q != '"' && *q != '\n') {
 				q++;
 			}