6 files changed, 36 insertions, 6 deletions
diff --git a/runtime/Intrinsic/Makefile b/runtime/Intrinsic/Makefile
index 849bfeee..3c6b01b3 100644
--- a/runtime/Intrinsic/Makefile
+++ b/runtime/Intrinsic/Makefile
@@ -17,6 +17,7 @@ BYTECODE_LIBRARY=1
 DEBUG_RUNTIME=1
 NO_PEDANTIC=1
 
+MODULE_NAME=kleeRuntimeIntrinsic
 C.Flags += -fno-builtin
 
 include $(LEVEL)/Makefile.common
diff --git a/runtime/Intrinsic/klee_overshift_check.c b/runtime/Intrinsic/klee_overshift_check.c
new file mode 100644
index 00000000..c0cb6102
--- /dev/null
+++ b/runtime/Intrinsic/klee_overshift_check.c
@@ -0,0 +1,31 @@
+//===-- klee_overshift_check.c ---------------------------------------------===//
+//
+//                     The KLEE Symbolic Virtual Machine
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <klee/klee.h>
+
+/* This instrumentation call is used to check for overshifting.
+ * If we do try to do x << y or x >> y
+ * where
+ *   bitWidth = sizeof(x)*8
+ *   shift = y
+ *
+ * then we can detect overshifting (which has undefined behaviour).
+ */
+void klee_overshift_check(unsigned long long bitWidth, unsigned long long shift) {
+  if (shift >= bitWidth) {
+    /* Maybe we shouldn't throw an error because
+     * overshifting can be non-fatal? Perhaps
+     * we should generate a test case but carry
+     * on executing the state with a warning?
+     */
+    klee_report_error("IGNORED", 0 /*Ignored */, "overshift error", "overshift.err");
+  }
+}
+
+
diff --git a/runtime/Intrinsic/memcpy.c b/runtime/Intrinsic/memcpy.c
index 7f7f133d..bd9f3e38 100644
--- a/runtime/Intrinsic/memcpy.c
+++ b/runtime/Intrinsic/memcpy.c
@@ -9,7 +9,7 @@
 
 #include <stdlib.h>
 
-void *memcpy(void *destaddr, void const *srcaddr, size_t len) {
+__attribute__((weak)) void *memcpy(void *destaddr, void const *srcaddr, size_t len) {
   char *dest = destaddr;
   char const *src = srcaddr;
 
diff --git a/runtime/Intrinsic/memmove.c b/runtime/Intrinsic/memmove.c
index c6e1ada9..e89abf7d 100644
--- a/runtime/Intrinsic/memmove.c
+++ b/runtime/Intrinsic/memmove.c
@@ -9,7 +9,7 @@
 
 #include <stdlib.h>
 
-void *memmove(void *dst, const void *src, size_t count) {
+__attribute__((weak)) void *memmove(void *dst, const void *src, size_t count) {
   char *a = dst;
   const char *b = src;
 
diff --git a/runtime/Intrinsic/mempcpy.c b/runtime/Intrinsic/mempcpy.c
index 31e142d9..e47a94b1 100644
--- a/runtime/Intrinsic/mempcpy.c
+++ b/runtime/Intrinsic/mempcpy.c
@@ -8,8 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include <stdlib.h>
-
-void *mempcpy(void *destaddr, void const *srcaddr, size_t len) {
+__attribute__((weak)) void *mempcpy(void *destaddr, void const *srcaddr, size_t len) {
   char *dest = destaddr;
   char const *src = srcaddr;
 
diff --git a/runtime/Intrinsic/memset.c b/runtime/Intrinsic/memset.c
index bef85e6a..c21f1fa9 100644
--- a/runtime/Intrinsic/memset.c
+++ b/runtime/Intrinsic/memset.c
@@ -8,8 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include <stdlib.h>
-
-void *memset(void * dst, int s, size_t count) {
+__attribute__ ((weak)) void *memset(void * dst, int s, size_t count) {
     volatile char * a = dst;
     while (count-- > 0)
       *a++ = s;