Update following rebase.

- update ubsan vptr codegen/tests for hash/mixer change
- adopt renamed siphash function; pass SmallString as StringRef
- bring back removed getConstantSignedPointer declaration
- move shouldSignPointer into CGM
- remove unneeded addSignedPointer variant
- move other addSignedPointer variant back to ConstantInitBuilder

Author: ahmedbougacha

clang/include/clang/CodeGen/ConstantInitBuilder.h

@@ -203,15 +203,9 @@ class ConstantAggregateBuilderBase {
   }
 
   /// Add a signed pointer using the given pointer authentication schema.
-  void addSignedPointer(llvm::Constant *pointer,
-                        const PointerAuthSchema &schema, GlobalDecl calleeDecl,
-                        QualType calleeType);
-
-  /// Add a signed pointer using the given pointer authentication schema.
-  void addSignedPointer(llvm::Constant *pointer,
-                        unsigned key,
-                        bool useAddressDiscrimination,
-                        llvm::ConstantInt *otherDiscriminator);
+  void addSignedPointer(llvm::Constant *Pointer,
+                        const PointerAuthSchema &Schema, GlobalDecl CalleeDecl,
+                        QualType CalleeType);
 
   /// Add a null pointer of a specific type.
   void addNullPointer(llvm::PointerType *ptrTy) {

clang/lib/AST/ASTContext.cpp

@@ -3112,7 +3112,7 @@ uint16_t ASTContext::getPointerAuthVTablePointerDiscriminator(
   SmallString<256> Str;
   llvm::raw_svector_ostream Out(Str);
   MC->mangleCXXVTable(record, Out);
-  return llvm::getPointerAuthStableSipHash(Str.c_str());
+  return llvm::getPointerAuthStableSipHash(Str);
 }
 
 QualType ASTContext::getObjCGCQualType(QualType T,

clang/lib/CodeGen/CGPointerAuth.cpp

@@ -140,7 +140,7 @@ CodeGenModule::getConstantSignedPointer(llvm::Constant *Pointer, unsigned Key,
 }
 
 /// Does a given PointerAuthScheme require us to sign a value
-static bool shouldSignPointer(const PointerAuthSchema &Schema) {
+bool CodeGenModule::shouldSignPointer(const PointerAuthSchema &Schema) {
   auto AuthenticationMode = Schema.getAuthenticationMode();
   return AuthenticationMode == PointerAuthenticationMode::SignAndStrip ||
          AuthenticationMode == PointerAuthenticationMode::SignAndAuth;
@@ -160,35 +160,6 @@ llvm::Constant *CodeGenModule::getConstantSignedPointer(
                                   OtherDiscriminator);
 }
 
-/// Sign the given pointer and add it to the constant initializer
-/// currently being built.
-void ConstantAggregateBuilderBase::addSignedPointer(
-    llvm::Constant *Pointer, const PointerAuthSchema &Schema,
-    GlobalDecl CalleeDecl, QualType CalleeType) {
-  if (!Schema || !shouldSignPointer(Schema))
-    return add(Pointer);
-
-  llvm::Constant *StorageAddress = nullptr;
-  if (Schema.isAddressDiscriminated())
-    StorageAddress = getAddrOfCurrentPosition(Pointer->getType());
-
-  llvm::Constant *SignedPointer = Builder.CGM.getConstantSignedPointer(
-      Pointer, Schema, StorageAddress, CalleeDecl, CalleeType);
-  add(SignedPointer);
-}
-
-void ConstantAggregateBuilderBase::addSignedPointer(
-    llvm::Constant *Pointer, unsigned Key, bool UseAddressDiscrimination,
-    llvm::ConstantInt *OtherDiscriminator) {
-  llvm::Constant *StorageAddress = nullptr;
-  if (UseAddressDiscrimination)
-    StorageAddress = getAddrOfCurrentPosition(Pointer->getType());
-
-  llvm::Constant *SignedPointer = Builder.CGM.getConstantSignedPointer(
-      Pointer, Key, StorageAddress, OtherDiscriminator);
-  add(SignedPointer);
-}
-
 /// If applicable, sign a given constant function pointer with the ABI rules for
 /// functionType.
 llvm::Constant *CodeGenModule::getFunctionPointer(llvm::Constant *Pointer,

clang/lib/CodeGen/CodeGenModule.h

@@ -964,6 +964,13 @@ class CodeGenModule : public CodeGenTypeCache {
 
   CGPointerAuthInfo getFunctionPointerAuthInfo(QualType T);
 
+  bool shouldSignPointer(const PointerAuthSchema &Schema);
+  llvm::Constant *getConstantSignedPointer(llvm::Constant *Pointer,
+                                           const PointerAuthSchema &Schema,
+                                           llvm::Constant *StorageAddress,
+                                           GlobalDecl SchemaDecl,
+                                           QualType SchemaType);
+
   llvm::Constant *
   getConstantSignedPointer(llvm::Constant *Pointer, unsigned Key,
                            llvm::Constant *StorageAddress,

clang/lib/CodeGen/ConstantInitBuilder.cpp

@@ -296,3 +296,21 @@ ConstantAggregateBuilderBase::finishStruct(llvm::StructType *ty) {
   buffer.erase(buffer.begin() + Begin, buffer.end());
   return constant;
 }
+
+/// Sign the given pointer and add it to the constant initializer
+/// currently being built.
+void ConstantAggregateBuilderBase::addSignedPointer(
+    llvm::Constant *Pointer, const PointerAuthSchema &Schema,
+    GlobalDecl CalleeDecl, QualType CalleeType) {
+  if (!Schema || !Builder.CGM.shouldSignPointer(Schema))
+    return add(Pointer);
+
+  llvm::Constant *StorageAddress = nullptr;
+  if (Schema.isAddressDiscriminated()) {
+    StorageAddress = getAddrOfCurrentPosition(Pointer->getType());
+  }
+
+  llvm::Constant *SignedPointer = Builder.CGM.getConstantSignedPointer(
+      Pointer, Schema, StorageAddress, CalleeDecl, CalleeType);
+  add(SignedPointer);
+}

clang/test/CodeGenCXX/ubsan-vtable-checks.cpp

@@ -33,7 +33,7 @@ int get_v(T* t) {
   // CHECK-PTRAUTH: [[STRIPPED_PTR:%.*]] = inttoptr i64 [[STRIPPED_VTABLE]] to ptr
   // CHECK-PTRAUTH: [[STRIPPED_INT:%.*]] = ptrtoint ptr [[STRIPPED_PTR]] to i64
   // Make sure authed vtable pointer feeds into hashing
-  // CHECK-PTRAUTH: {{%.*}} = xor i64 {{.*}}, [[STRIPPED_INT]]
+  // CHECK-PTRAUTH: {{%.*}} = mul i64 [[STRIPPED_INT]], {{.*}}
 
   // Verify that we authenticate for the actual vcall
   // CHECK-PTRAUTH: [[BLENDED:%.*]] = call i64 @llvm.ptrauth.blend(i64 {{%.*}}, i64 17113)
@@ -59,7 +59,7 @@ void delete_it(T *t) {
   // CHECK-PTRAUTH: [[STRIPPED_VTABLE:%.*]] = call i64 @llvm.ptrauth.strip(i64 [[CAST_VTABLE]], i32 0)
   // CHECK-PTRAUTH: [[STRIPPED_PTR:%.*]] = inttoptr i64 [[STRIPPED_VTABLE]] to ptr
   // CHECK-PTRAUTH: [[STRIPPED_INT:%.*]] = ptrtoint ptr [[STRIPPED_PTR]] to i64
-  // CHECK-PTRAUTH: {{%.*}} = xor i64 {{.*}}, [[STRIPPED_INT]]
+  // CHECK-PTRAUTH: {{%.*}} = mul i64 [[STRIPPED_INT]], {{.*}}
   // CHECK-PTRAUTH: call void @__ubsan_handle_dynamic_type_cache_miss_abort(
   // Second, we check that vtable is actually loaded once the type check is done.
   // ptrauth for the virtual function load
@@ -85,7 +85,7 @@ U* dyncast(T *t) {
   // CHECK-PTRAUTH: [[STRIPPED_VTABLE:%.*]] = call i64 @llvm.ptrauth.strip(i64 [[CAST_VTABLE]], i32 0)
   // CHECK-PTRAUTH: [[STRIPPED_PTR:%.*]] = inttoptr i64 [[STRIPPED_VTABLE]] to ptr
   // CHECK-PTRAUTH: [[STRIPPED_INT:%.*]] = ptrtoint ptr [[STRIPPED_PTR]] to i64
-  // CHECK-PTRAUTH: {{%.*}} = xor i64 {{.*}}, [[STRIPPED_INT]]
+  // CHECK-PTRAUTH: {{%.*}} = mul i64 [[STRIPPED_INT]], {{.*}}
   // CHECK-VPTR: call void @__ubsan_handle_dynamic_type_cache_miss_abort
   // CHECK-PTRAUTH: [[BLENDED:%.*]] = call i64 @llvm.ptrauth.blend(i64 {{%.*}}, i64 17113)
   // CHECK-PTRAUTH: [[CAST_VTABLE:%.*]] = ptrtoint ptr %vtable1 to i64