Refactored dtor sanitizing into EHScopeStack

Summary:
Dtor sanitization handled amidst other dtor cleanups,
between cleaning bases and fields. Sanitizer call pushed onto
stack of cleanup operations.

Reviewers: eugenis, kcc

Differential Revision: http://reviews.llvm.org/D12022

Refactoring dtor sanitizing emission order.

- Support multiple inheritance by poisoning after
 member destructors are invoked, and before base
 class destructors are invoked.
- Poison for virtual destructor and virtual bases.
- Repress dtor aliasing when sanitizing in dtor.
- CFE test for dtor aliasing, and repression of aliasing in dtor
 code generation.
- Poison members on field-by-field basis, with collective poisoning
 of trivial members when possible.
- Check msan flags and existence of fields, before dtor sanitizing,
 and when determining if aliasing is allowed.
- Testing sanitizing bit fields.

llvm-svn: 246815

3 files changed, 196 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/sanitize-dtor-bit-field.cpp b/clang/test/CodeGenCXX/sanitize-dtor-bit-field.cpp
new file mode 100644
index 00000000000..d4497f6aac0
--- /dev/null
+++ b/clang/test/CodeGenCXX/sanitize-dtor-bit-field.cpp
@@ -0,0 +1,84 @@
+// Test -fsanitize-memory-use-after-dtor
+// 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
+
+// 24 bytes total
+struct Packed {
+  // Packed into 4 bytes
+  unsigned int a : 1;
+  unsigned int b : 1;
+  //unsigned int c : 1;
+  // Force alignment to next 4 bytes
+  unsigned int   : 0;
+  unsigned int d : 1;
+  // Force alignment, 8 more bytes
+  double e = 5.0;
+  // 4 bytes
+  unsigned int f : 1;
+  ~Packed() {}
+};
+Packed p;
+
+
+// 1 byte total
+struct Empty {
+  unsigned int : 0;
+  ~Empty() {}
+};
+Empty e;
+
+
+// 4 byte total
+struct Simple {
+  unsigned int a : 1;
+  ~Simple() {}
+};
+Simple s;
+
+
+// 8 bytes total
+struct Anon {
+  // 1 byte
+  unsigned int a : 1;
+  unsigned int b : 2;
+  // Force alignment to next byte
+  unsigned int   : 0;
+  unsigned int c : 1;
+  ~Anon() {}
+};
+Anon an;
+
+
+struct CharStruct {
+  char c;
+  ~CharStruct();
+};
+
+struct Adjacent {
+  CharStruct a;
+  int b : 1;
+  CharStruct c;
+  ~Adjacent() {}
+};
+Adjacent ad;
+
+
+// CHECK-LABEL: define {{.*}}PackedD2Ev
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 17
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}EmptyD2Ev
+// CHECK-NOT: call void @__sanitizer_dtor_callback{{.*}}i64 0
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}SimpleD2Ev
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 1
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}AnonD2Ev
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 5
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}AdjacentD2Ev
+// CHECK: call void @__sanitizer_dtor_callback{{.*}}i64 1
+// CHECK: ret void
diff --git a/clang/test/CodeGenCXX/sanitize-dtor-nontrivial-virtual-base.cpp b/clang/test/CodeGenCXX/sanitize-dtor-nontrivial-virtual-base.cpp
new file mode 100644
index 00000000000..27eb64b5534
--- /dev/null
+++ b/clang/test/CodeGenCXX/sanitize-dtor-nontrivial-virtual-base.cpp
@@ -0,0 +1,82 @@
+// RUN: %clang_cc1 -fsanitize=memory -O0 -fsanitize-memory-use-after-dtor -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -fsanitize=memory -O1 -fsanitize-memory-use-after-dtor -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+
+template <class T>
+class Vector {
+public:
+  int size;
+  ~Vector() {
+    size += 1;
+  }
+};
+
+struct Base {
+  int b1;
+  double b2;
+  Base() {
+    b1 = 5;
+    b2 = 10.989;
+  }
+  virtual ~Base() {}
+};
+
+struct VirtualBase {
+  int vb1;
+  int vb2;
+  VirtualBase() {
+    vb1 = 10;
+    vb2 = 11;
+  }
+  virtual ~VirtualBase() {}
+};
+
+struct Derived : public Base, public virtual VirtualBase {
+  int d1;
+  Vector<int> v;
+  int d2;
+  Derived() {
+    d1 = 10;
+  }
+  ~Derived() {}
+};
+
+Derived d;
+
+// Destruction order:
+// Derived: int, Vector, Base, VirtualBase
+
+// CHECK-LABEL: define {{.*}}ZN7DerivedD1Ev
+// CHECK: call void {{.*}}ZN11VirtualBaseD2Ev
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}ZN7DerivedD0Ev
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}ZN11VirtualBaseD1Ev
+// CHECK: ret void
+
+// CHECK-LABEL: define {{.*}}ZN11VirtualBaseD0Ev
+// CHECK: ret void
+
+// poison 2 ints
+// CHECK-LABEL: define {{.*}}ZN11VirtualBaseD2Ev
+// CHECK: call void {{.*}}sanitizer_dtor_callback({{.*}}, i64 8)
+// CHECK: ret void
+
+// poison int and double
+// CHECK-LABEL: define {{.*}}ZN4BaseD2Ev
+// CHECK: call void {{.*}}sanitizer_dtor_callback({{.*}}, i64 16)
+// CHECK: ret void
+
+// poison int, ignore vector, poison int
+// CHECK-LABEL: define {{.*}}ZN7DerivedD2Ev
+// CHECK: call void {{.*}}ZN6VectorIiED1Ev
+// CHECK: call void {{.*}}sanitizer_dtor_callback({{.*}}, i64 4)
+// CHECK: call void {{.*}}sanitizer_dtor_callback({{.*}}, i64 4)
+// CHECK: call void {{.*}}ZN4BaseD2Ev
+// CHECK: ret void
+
+// poison int
+// CHECK-LABEL: define {{.*}}ZN6VectorIiED2Ev
+// CHECK: call void {{.*}}sanitizer_dtor_callback({{.*}}, i64 4)
+// CHECK: ret void
diff --git a/clang/test/CodeGenCXX/sanitize-dtor-repress-aliasing.cpp b/clang/test/CodeGenCXX/sanitize-dtor-repress-aliasing.cpp
new file mode 100644
index 00000000000..28624a0e7ae
--- /dev/null
+++ b/clang/test/CodeGenCXX/sanitize-dtor-repress-aliasing.cpp
@@ -0,0 +1,30 @@
+// Test -fsanitize-memory-use-after-dtor
+// RUN: %clang_cc1 -fsanitize=memory -O1 -fsanitize-memory-use-after-dtor -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -fsanitize=memory -O2 -fsanitize-memory-use-after-dtor -std=c++11 -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
+
+template <class T>
+class Vector {
+public:
+  int size;
+  ~Vector() {}
+};
+
+// Virtual function table for the derived class only contains
+// its own destructors, with no aliasing to base class dtors.
+struct Base {
+  Vector<int> v;
+  int x;
+  Base() { x = 5; }
+  virtual ~Base() {}
+};
+
+struct Derived : public Base {
+  int z;
+  Derived() { z = 10; }
+  ~Derived() {}
+};
+
+Derived d;
+
+// Definition of virtual function table
+// CHECK: @_ZTV7Derived = {{.*}}@_ZN7DerivedD1Ev{{.*}}@_ZN7DerivedD0Ev