[PATCH] D11109: basic code generation for use-after-dtor

[Naomi Musgrave]

nmusgrave updated this revision to Diff 29595.
nmusgrave added a comment.

- passing in array instead of vector, simple codegen tests started


http://reviews.llvm.org/D11109

Files:
  lib/CodeGen/CGClass.cpp
  test/CodeGen/sanitize-dtor-usage.cpp

Index: test/CodeGen/sanitize-dtor-usage.cpp
===================================================================
--- /dev/null
+++ test/CodeGen/sanitize-dtor-usage.cpp
@@ -0,0 +1,22 @@
+// Test -fsanitize-memory-use-after-dtor
+// RUN: %clang_cc1 -fsanitize=memory -fsanitize-memory-use-after-dtor -emit-llvm -o - %s | FileCheck %s --check-prefix=DTOR
+
+//#include <sanitizer/msan_interface.h>
+struct A {
+  int x_;
+  A() {
+    x_ = 5;
+  }
+  ~A() {
+    // __msan_poison(this, sizeof(*this));
+  }
+};
+int main() {
+  A a;
+  a.~A();
+  //__msan_check_mem_is_initialized(&a.x_, sizeof(a.x_));
+}
+
+// Check that MSan destructor sanitization poisons simple internal attribute
+// DTOR: call void @__sanitizer_dtor_callback
+// CHECK: ret void
Index: lib/CodeGen/CGClass.cpp
===================================================================
--- lib/CodeGen/CGClass.cpp
+++ lib/CodeGen/CGClass.cpp
@@ -1448,6 +1448,29 @@
   // Exit the try if applicable.
   if (isTryBody)
     ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true);
+
+  // Insert memory-posioning instrumentation.
+  // Generates function call for handling object poisoning, passing in
+  // references to 'this' and its size as arguments.
+  if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor) {
+    const ASTRecordLayout &Layout =
+        getContext().getASTRecordLayout(Dtor->getParent());
+
+    llvm::Value *Args[2] = {
+      Builder.CreateBitCast(LoadCXXThis(), VoidPtrTy),
+      llvm::ConstantInt::get(CGM.SizeTy, Layout.getSize().getQuantity())
+    };
+    llvm::Type *ArgTypes[2] = {
+      VoidPtrTy,
+      SizeTy
+    };
+
+    llvm::FunctionType *FnType =
+        llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
+    llvm::Value *Fn =
+        CGM.CreateRuntimeFunction(FnType, "__sanitizer_dtor_callback");
+    EmitNounwindRuntimeCall(Fn, Args);
+  }
 }
 
 void CodeGenFunction::emitImplicitAssignmentOperatorBody(FunctionArgList &Args) {


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