Resign pointer when materializing temporary

Author: ahatanak

clang/lib/CodeGen/CGExpr.cpp

@@ -527,7 +527,15 @@ EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
     // initialized it.
     if (!Var->hasInitializer()) {
       Var->setInitializer(CGM.EmitNullConstant(E->getType()));
-      EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
+      QualType RefType = M->getType();
+      if (RefType.getPointerAuth()) {
+        // Use the qualifier of the reference temporary to sign the pointer.
+        auto LV = MakeRawAddrLValue(Object.getPointer(), RefType,
+                                    Object.getAlignment());
+        EmitScalarInit(E, M->getExtendingDecl(), LV, false);
+      } else {
+        EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/ true);
+      }
     }
   } else {
     switch (M->getStorageDuration()) {

clang/test/CodeGen/ptrauth-qualifier-function.c

@@ -82,14 +82,51 @@ void test_const_ptr_function_call(void) {
 #ifdef __cplusplus
 void (* get_fptr(void))(int);
 void (* __ptrauth(0, 0, 42) f_const_ptr2)(int) = get_fptr();
-void (* const __ptrauth(0, 0, 42) &f_ref)(int) = f_const_ptr2;
+void (* const __ptrauth(0, 1, 43) &f_ref)(int) = f_const_ptr2;
+
+// CHECK-CXX-LABEL: define internal void @__cxx_global_var_init()
+// CHECK-CXX: [[ENTRY:.*]]:
+// CHECK-CXX: %[[CALL:.*]] = call ptr @get_fptr()
+// CHECK-CXX: %[[V0:.*]] = icmp ne ptr %[[CALL]], null
+// CHECK-CXX: br i1 %[[V0]], label %[[RESIGN_NONNULL:.*]], label %[[RESIGN_CONT:.*]]
+
+// CHECK-CXX: [[RESIGN_NONNULL]]:
+// CHECK-CXX: %[[V1:.*]] = ptrtoint ptr %[[CALL]] to i64
+// CHECK-CXX: %[[V2:.*]] = call i64 @llvm.ptrauth.resign(i64 %[[V1]], i32 0, i64 2712, i32 0, i64 42)
+// CHECK-CXX: %[[V3:.*]] = inttoptr i64 %[[V2]] to ptr
+// CHECK-CXX: br label %[[RESIGN_CONT]]
+
+// CHECK-CXX: [[RESIGN_CONT]]:
+// CHECK-CXX: %[[V4:.*]] = phi ptr [ null, %[[ENTRY]] ], [ %[[V3]], %[[RESIGN_NONNULL]] ]
+// CHECK-CXX: store ptr %[[V4]], ptr @f_const_ptr2, align 8
+
+// CHECK-CXX-LABEL: define internal void @__cxx_global_var_init.1()
+// CHECK-CXX: [[ENTRY:.*]]:
+// CHECK-CXX: %[[V0:.*]] = load ptr, ptr @f_const_ptr2, align 8
+// CHECK-CXX: %[[V1:.*]] = call i64 @llvm.ptrauth.blend(i64 ptrtoint (ptr @_ZGR5f_ref_ to i64), i64 43)
+// CHECK-CXX: %[[V2:.*]] = icmp ne ptr %[[V0]], null
+// CHECK-CXX: br i1 %[[V2]], label %[[RESIGN_NONNULL:.*]], label %[[RESIGN_CONT:.*]]
+
+// CHECK-CXX: [[RESIGN_NONNULL]]:
+// CHECK-CXX: %[[V3:.*]] = ptrtoint ptr %[[V0]] to i64
+// CHECK-CXX: %[[V4:.*]] = call i64 @llvm.ptrauth.resign(i64 %[[V3]], i32 0, i64 42, i32 0, i64 %[[V1]])
+// CHECK-CXX: %[[V5:.*]] = inttoptr i64 %[[V4]] to ptr
+// CHECK-CXX: br label %[[RESIGN_CONT]]
+
+// CHECK-CXX: [[RESIGN_CONT]]:
+// CHECK-CXX: %[[V6:.*]] = phi ptr [ null, %[[ENTRY]] ], [ %[[V5]], %[[RESIGN_NONNULL]] ]
+// CHECK-CXX: store ptr %[[V6]], ptr @_ZGR5f_ref_, align 8
+// CHECK-CXX: store ptr @_ZGR5f_ref_, ptr @f_ref, align 8
 
 // CHECK-CXX-LABEL: define void @test_const_ptr_ref_function_call()
 void test_const_ptr_ref_function_call(void) {
   f_ref(1);
 
-  // CHECK-CXX: %[[V0:.*]] = load ptr, ptr @f_const_ptr2, align 8
-  // CHECK-CXX: call void %[[V0]](i32 noundef 1) [ "ptrauth"(i32 0, i64 42) ]
+  // CHECK-CXX: %[[V0:.*]] = load ptr, ptr @f_ref, align 8
+  // CHECK-CXX: %[[V1:.*]] = load ptr, ptr %[[V0]], align 8
+  // CHECK-CXX: %[[V2:.*]] = ptrtoint ptr %[[V0]] to i64
+  // CHECK-CXX: %[[V3:.*]] = call i64 @llvm.ptrauth.blend(i64 %[[V2]], i64 43)
+  // CHECK-CXX: call void %[[V1]](i32 noundef 1) [ "ptrauth"(i32 0, i64 %[[V3]]) ]
 }
 }
 #endif