From 1b322f5fe45adfc02a8f841d149dd826ecb2cb8e Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Wed, 28 Apr 2010 21:21:42 +0200
Subject: [PATCH] Don't hash -U in the preprocessor mode

---
 NEWS.txt | 4 ++++
 ccache.c | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/NEWS.txt b/NEWS.txt
index 03797adfb..e5b3f166c 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -100,6 +100,10 @@ New features and improvements
     - For debugging purposes, the variable `CCACHE_VERBOSE` may now be set to
       make ccache print executed commands to standard output.
 
+    - The following options are no longer hashed in the preprocessor mode:
+      `-imacros`, `-iprefix`, `-iwithprefix`, `-iwithprefixbefore`,
+      `-nostdinc`, `-nostdinc++` and `-U`.
+
 
 Bug fixes
 ~~~~~~~~~
diff --git a/ccache.c b/ccache.c
index ea25a2778..1cd4cec70 100644
--- a/ccache.c
+++ b/ccache.c
@@ -863,7 +863,8 @@ static struct file_hash *calculate_object_hash(
 				    strcmp(args->argv[i], "-idirafter") == 0 ||
 				    strcmp(args->argv[i], "-isystem") == 0 ||
 				    strcmp(args->argv[i], "-nostdinc") == 0 ||
-				    strcmp(args->argv[i], "-nostdinc++") == 0) {
+				    strcmp(args->argv[i], "-nostdinc++") == 0 ||
+				    strcmp(args->argv[i], "-U") == 0) {
 					/* Skip from hash. */
 					i++;
 					continue;
-- 
2.47.3