r178538 - [ASan] Emit lifetime markers for local variables in -fsanitize=use-after-scope mode

[Alexey Samsonov]

Author: samsonov
Date: Tue Apr  2 08:19:46 2013
New Revision: 178538

URL: http://llvm.org/viewvc/llvm-project?rev=178538&view=rev
Log:
[ASan] Emit lifetime markers for local variables in -fsanitize=use-after-scope mode

Added:
    cfe/trunk/test/CodeGen/sanitize-use-after-scope.c
Modified:
    cfe/trunk/lib/CodeGen/CGDecl.cpp

Modified: cfe/trunk/lib/CodeGen/CGDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDecl.cpp?rev=178538&r1=178537&r2=178538&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDecl.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDecl.cpp Tue Apr  2 08:19:46 2013
@@ -786,6 +786,9 @@ static bool shouldUseMemSetPlusStoresToI
 /// Should we use the LLVM lifetime intrinsics for the given local variable?
 static bool shouldUseLifetimeMarkers(CodeGenFunction &CGF, const VarDecl &D,
                                      unsigned Size) {
+  // Always emit lifetime markers in -fsanitize=use-after-scope mode.
+  if (CGF.getLangOpts().Sanitize.UseAfterScope)
+    return true;
   // For now, only in optimized builds.
   if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0)
     return false;

Added: cfe/trunk/test/CodeGen/sanitize-use-after-scope.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/sanitize-use-after-scope.c?rev=178538&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/sanitize-use-after-scope.c (added)
+++ cfe/trunk/test/CodeGen/sanitize-use-after-scope.c Tue Apr  2 08:19:46 2013
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -S -emit-llvm -o - -fsanitize=address,use-after-scope %s \
+// RUN:     | FileCheck %s -check-prefix=USE-AFTER-SCOPE
+// RUN: %clang_cc1 -S -emit-llvm -o - -fsanitize=address %s \
+// RUN:     | FileCheck %s -check-prefix=ADDRESS-ONLY
+
+extern int bar(char *A, int n);
+
+// ADDRESS-ONLY-NOT: @llvm.lifetime.start
+int foo (int n) {
+  if (n) {
+    // USE-AFTER-SCOPE: @llvm.lifetime.start(i64 10, i8* {{.*}})
+    char A[10];
+    return bar(A, 1);
+    // USE-AFTER-SCOPE: @llvm.lifetime.end(i64 10, i8* {{.*}})
+  } else {
+    // USE-AFTER-SCOPE: @llvm.lifetime.start(i64 20, i8* {{.*}})
+    char A[20];
+    return bar(A, 2);
+    // USE-AFTER-SCOPE: @llvm.lifetime.end(i64 20, i8* {{.*}})
+  }
+}
+