[klee] r146350 - in /klee/trunk/runtime/Intrinsic: Makefile memset.c

[Cristian Cadar]

Author: cristic
Date: Sun Dec 11 15:29:52 2011
New Revision: 146350

URL: http://llvm.org/viewvc/llvm-project?rev=146350&view=rev
Log:
This is a workaround for the infinite loop reported at 
http://keeda.stanford.edu/pipermail/klee-dev/2011-August/000723.html

KLEE needs to use --fno-builtin when compiling its version of memset.
However, this patch also adds the workaround suggested by Paul in the
thread above, since support for --fno-builtin was added to llvm-gcc only
after LLVM 2.9 was released.

More details about this issue can be found here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110411/119376.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110711/124131.html

Thanks to Paul and arrowdodger for their explanations and patches.


Modified:
    klee/trunk/runtime/Intrinsic/Makefile
    klee/trunk/runtime/Intrinsic/memset.c

Modified: klee/trunk/runtime/Intrinsic/Makefile
URL: http://llvm.org/viewvc/llvm-project/klee/trunk/runtime/Intrinsic/Makefile?rev=146350&r1=146349&r2=146350&view=diff
==============================================================================
--- klee/trunk/runtime/Intrinsic/Makefile (original)
+++ klee/trunk/runtime/Intrinsic/Makefile Sun Dec 11 15:29:52 2011
@@ -17,4 +17,6 @@
 DEBUG_RUNTIME=1
 NO_PEDANTIC=1
 
+C.Flags += -fno-builtin
+
 include $(LEVEL)/Makefile.common

Modified: klee/trunk/runtime/Intrinsic/memset.c
URL: http://llvm.org/viewvc/llvm-project/klee/trunk/runtime/Intrinsic/memset.c?rev=146350&r1=146349&r2=146350&view=diff
==============================================================================
--- klee/trunk/runtime/Intrinsic/memset.c (original)
+++ klee/trunk/runtime/Intrinsic/memset.c Sun Dec 11 15:29:52 2011
@@ -10,7 +10,7 @@
 #include <stdlib.h>
 
 void *memset(void * dst, int s, size_t count) {
-    char * a = dst;
+    volatile char * a = dst;
     while (count-- > 0)
       *a++ = s;
     return dst;