From: Joel Rosdahl <joel@rosdahl.net>
Date: Fri, 8 Jul 2016 15:21:18 +0000 (+0200)
Subject: Don't rewrite source file path if it's absolute and a symlink
X-Git-Tag: v3.1.12~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49c9f13e6f825460218d6c54f3878215c0e54e4d;p=thirdparty%2Fccache.git

Don't rewrite source file path if it's absolute and a symlink

Fixes issue #111.
---

diff --git a/NEWS.txt b/NEWS.txt
index 849a10f11..d1956611f 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -2,6 +2,19 @@ ccache news
 ===========
 
 
+ccache 3.1.12
+-------------
+Release date: unknown
+
+
+Bug fixes
+~~~~~~~~~
+
+- Fixed a bug where (due to ccache rewriting paths) the compiler could choose
+  incorrect include files if `CCACHE_BASEDIR` is used and the source file path
+  is absolute and is a symlink.
+
+
 ccache 3.1.11
 -------------
 Release date: 2015-03-07
diff --git a/ccache.c b/ccache.c
index 1f182630d..d3e523023 100644
--- a/ccache.c
+++ b/ccache.c
@@ -2,7 +2,7 @@
  * ccache -- a fast C/C++ compiler cache
  *
  * Copyright (C) 2002-2007 Andrew Tridgell
- * Copyright (C) 2009-2015 Joel Rosdahl
+ * Copyright (C) 2009-2016 Joel Rosdahl
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
@@ -1747,8 +1747,17 @@ cc_process_args(struct args *orig_args, struct args **preprocessor_args,
 			goto out;
 		}
 
-		/* Rewrite to relative to increase hit rate. */
-		input_file = make_relative_path(x_strdup(argv[i]));
+		lstat(argv[i], &st);
+		if (S_ISLNK(st.st_mode)) {
+			/* Don't rewrite source file path if it's a symlink since
+			   make_relative_path resolves symlinks using realpath(3) and this leads
+			   to potentially choosing incorrect relative header files. See the
+			   "symlink to source file" test. */
+			input_file = x_strdup(argv[i]);
+		} else {
+			/* Rewrite to relative to increase hit rate. */
+			input_file = make_relative_path(x_strdup(argv[i]));
+		}
 	}
 
 	if (!input_file) {
diff --git a/test.sh b/test.sh
index 5efbca4f7..490e97576 100755
--- a/test.sh
+++ b/test.sh
@@ -3,7 +3,7 @@
 # A simple test suite for ccache.
 #
 # Copyright (C) 2002-2007 Andrew Tridgell
-# Copyright (C) 2009-2015 Joel Rosdahl
+# Copyright (C) 2009-2016 Joel Rosdahl
 #
 # This program is free software; you can redistribute it and/or modify it under
 # the terms of the GNU General Public License as published by the Free Software
@@ -1837,6 +1837,59 @@ EOF
     checkstat 'cache miss' 2
 }
 
+symlinks_suite() {
+    ##################################################################
+    testname="symlink to source directory"
+
+    mkdir dir
+    cd dir
+    mkdir -p d1/d2
+    echo '#define A "OK"' >d1/h.h
+    cat <<EOF >d1/d2/c.c
+#include <stdio.h>
+#include "../h.h"
+int main() { printf("%s\n", A); }
+EOF
+    echo '#define A "BUG"' >h.h
+    ln -s d1/d2 d3
+
+    CCACHE_BASEDIR=/ $CCACHE $COMPILER -c $PWD/d3/c.c
+    $COMPILER -c $PWD/d3/c.c
+    $COMPILER c.o -o c
+    result=$(./c)
+    if [ "$result" != OK ]; then
+        test_failed "Incorrect header file used"
+    fi
+
+    cd ..
+    rm -rf dir
+
+    ##################################################################
+    testname="symlink to source file"
+
+    mkdir dir
+    cd dir
+    mkdir d
+    echo '#define A "BUG"' >d/h.h
+    cat <<EOF >d/c.c
+#include <stdio.h>
+#include "h.h"
+int main() { printf("%s\n", A); }
+EOF
+    echo '#define A "OK"' >h.h
+    ln -s d/c.c c.c
+
+    CCACHE_BASEDIR=/ $CCACHE $COMPILER -c $PWD/c.c
+    $COMPILER c.o -o c
+    result=$(./c)
+    if [ "$result" != OK ]; then
+        test_failed "Incorrect header file used"
+    fi
+
+    cd ..
+    rm -rf dir
+}
+
 ######################################################################
 # main program
 
@@ -1885,6 +1938,7 @@ readonly
 extrafiles
 cleanup
 pch
+symlinks
 "
 
 host_os="`uname -s`"