Implementation and testing for poisoning vtable

ptr in dtor.

Summary:
After destruction, invocation of virtual functions prevented
by poisoning vtable pointer.

Reviewers: eugenis, kcc

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D12712

Fixed testing callback emission order to account for vptr.
Poison vtable in either complete or base dtor, depending on
if virtual bases exist. If virtual bases exist, poison in
complete dtor. Otherwise, poison in base.
Remove commented-out block.

llvm-svn: 247762

2 files changed, 56 insertions, 3 deletions

diff --git a/clang/test/CodeGenCXX/sanitize-dtor-derived-class.cpp b/clang/test/CodeGenCXX/sanitize-dtor-derived-class.cpp
index 723a504dd71..f3134711824 100644
--- a/clang/test/CodeGenCXX/sanitize-dtor-derived-class.cpp
+++ b/clang/test/CodeGenCXX/sanitize-dtor-derived-class.cpp
@@ -1,8 +1,9 @@
 // RUN: %clang_cc1 -fsanitize=memory -fsanitize-memory-use-after-dtor -disable-llvm-optzns -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
 // RUN: %clang_cc1 -O1 -fsanitize=memory -fsanitize-memory-use-after-dtor -disable-llvm-optzns -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
 
-// Only the last dtor of a class invokes the sanitizing callback
-// Sanitizing callback emited prior to base class dtor invocations
+// Base dtor poisons members
+// Complete dtor poisons vtable ptr after destroying members and
+// virtual bases
 
 class Base {
  public:
@@ -28,6 +29,7 @@ class Derived : public Base {
 
 Derived d;
 
+// Invoke base destructor. No vtable pointer to poison.
 // CHECK-LABEL: define {{.*}}DerivedD1Ev
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: call void {{.*}}DerivedD2Ev
@@ -40,6 +42,7 @@ Derived d;
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
 
+// Invokes base destructor, and poison vtable pointer.
 // CHECK-LABEL: define {{.*}}BaseD1Ev
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: call void {{.*}}BaseD2Ev
@@ -52,14 +55,17 @@ Derived d;
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
 
+// Poison members and vtable ptr.
 // CHECK-LABEL: define {{.*}}BaseD2Ev
 // CHECK: call void @__sanitizer_dtor_callback
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 8
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: ret void
 
+// Poison members and destroy non-virtual base.
 // CHECK-LABEL: define {{.*}}DerivedD2Ev
 // CHECK: call void @__sanitizer_dtor_callback
 // CHECK-NOT: call void @__sanitizer_dtor_callback
 // CHECK: call void {{.*}}BaseD2Ev
-// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 8
 // CHECK: ret void
diff --git a/clang/test/CodeGenCXX/sanitize-dtor-vtable.cpp b/clang/test/CodeGenCXX/sanitize-dtor-vtable.cpp
new file mode 100644
index 00000000000..78be7949c32
--- /dev/null
+++ b/clang/test/CodeGenCXX/sanitize-dtor-vtable.cpp
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -O0 -fsanitize=memory -fsanitize-memory-use-after-dtor -disable-llvm-optzns -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -O1 -fsanitize=memory -fsanitize-memory-use-after-dtor -disable-llvm-optzns -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+
+class A {
+ public:
+  int x;
+  A() {}
+  virtual ~A() {}
+};
+A a;
+
+class B : virtual public A {
+ public:
+  int y;
+  B() {}
+  ~B() {}
+};
+B b;
+
+// CHECK-LABEL: define {{.*}}AD1Ev
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: call void {{.*}}AD2Ev
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: ret void
+
+// After invoking base dtor and dtor for virtual base, poison vtable ptr.
+// CHECK-LABEL: define {{.*}}BD1Ev
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: call void {{.*}}BD2Ev
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: call void {{.*}}AD2Ev
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 8
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: ret void
+
+// Since no virtual bases, poison vtable ptr here.
+// CHECK-LABEL: define {{.*}}AD2Ev
+// CHECK: call void @__sanitizer_dtor_callback
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 8
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: ret void
+
+// Poison members
+// CHECK-LABEL: define {{.*}}BD2Ev
+// CHECK: call void @__sanitizer_dtor_callback
+// CHECK-NOT: call void @__sanitizer_dtor_callback
+// CHECK: ret void