ModuleUtil: improve and test valueIsOnlyCalled

  * handle BlockAddress (which is not a valid function pointer)
  * there is no instruction with opcode 0
  * add test for functionality

1 files changed, 49 insertions, 0 deletions

diff --git a/test/Feature/EscapingFunctions.c b/test/Feature/EscapingFunctions.c
new file mode 100644
index 00000000..8c9612a5
--- /dev/null
+++ b/test/Feature/EscapingFunctions.c
@@ -0,0 +1,49 @@
+// RUN: %llvmgcc -emit-llvm -O0 -g -c %s -o %t.bc
+// RUN: rm -rf %t.klee-out
+// RUN: %klee -debug-print-escaping-functions --output-dir=%t.klee-out %t.bc 2> %t.log
+// RUN: FileCheck --input-file=%t.log %s
+
+int functionpointer(void) {
+    return 1;
+}
+
+int functionpointer_as_argument(void) {
+    return 2;
+}
+
+short bitcasted_functionpointer(void) {
+    return 3;
+}
+
+int receives_functionpointer(int (*f)(void));
+
+int blockaddress(int x) {
+    void * target = &&one;
+    switch (x) {
+        case 1: break;
+        case 2:
+            target = &&two;
+            goto *target;
+        default:
+            goto *target;
+    }
+one:
+    return 1;
+two:
+    return 2;
+}
+
+int main(int argc, char *argv[]) {
+    int (*f1)(void) = functionpointer;
+    f1();
+
+    receives_functionpointer(functionpointer_as_argument);
+
+    int (*f2)(void) =(int (*)(void))bitcasted_functionpointer;
+    f2();
+
+    blockaddress(argc);
+
+    // CHECK: KLEE: escaping functions: {{\[((functionpointer|functionpointer_as_argument|bitcasted_functionpointer), ){3}\]}}
+    return 0;
+}