https://github.com/andykaylor created https://github.com/llvm/llvm-project/pull/167370
This adds handling in CIR's ScalarExprEmitter for CK_DerivedToBase cast expressions. >From 719dfa81f765367f7de62933f4e983ba636d5328 Mon Sep 17 00:00:00 2001 From: Andy Kaylor <[email protected]> Date: Fri, 7 Nov 2025 15:36:49 -0800 Subject: [PATCH] [CIR] Handle scalar DerivedToBase cast expressions This adds handling in CIR's ScalarExprEmitter for CK_DerivedToBase cast expressions. --- clang/include/clang/CIR/MissingFeatures.h | 1 + clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp | 8 ++ clang/lib/CIR/CodeGen/CIRGenFunction.h | 6 + clang/lib/CIR/CodeGen/CIRGenPointerAuth.cpp | 23 ++++ clang/lib/CIR/CodeGen/CMakeLists.txt | 1 + clang/test/CIR/CodeGen/derived-to-base.cpp | 129 ++++++++++++++++++++ 6 files changed, 168 insertions(+) create mode 100644 clang/lib/CIR/CodeGen/CIRGenPointerAuth.cpp create mode 100644 clang/test/CIR/CodeGen/derived-to-base.cpp diff --git a/clang/include/clang/CIR/MissingFeatures.h b/clang/include/clang/CIR/MissingFeatures.h index af1ffffcf54c0..3f6fab0447445 100644 --- a/clang/include/clang/CIR/MissingFeatures.h +++ b/clang/include/clang/CIR/MissingFeatures.h @@ -294,6 +294,7 @@ struct MissingFeatures { static bool opTBAA() { return false; } static bool peepholeProtection() { return false; } static bool pgoUse() { return false; } + static bool pointerAuthentication() { return false; } static bool pointerOverflowSanitizer() { return false; } static bool preservedAccessIndexRegion() { return false; } static bool requiresCleanups() { return false; } diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp index 5eba5ba6c3df1..3f40cf0c0027a 100644 --- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp @@ -1929,6 +1929,14 @@ mlir::Value ScalarExprEmitter::VisitCastExpr(CastExpr *ce) { return builder.createIntToPtr(middleVal, destCIRTy); } + case CK_UncheckedDerivedToBase: + case CK_DerivedToBase: { + // The EmitPointerWithAlignment path does this fine; just discard + // the alignment. + return cgf.getAsNaturalPointerTo(cgf.emitPointerWithAlignment(ce), + ce->getType()->getPointeeType()); + } + case CK_Dynamic: { Address v = cgf.emitPointerWithAlignment(subExpr); const auto *dce = cast<CXXDynamicCastExpr>(ce); diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.h b/clang/lib/CIR/CodeGen/CIRGenFunction.h index f879e580989f7..cab4a3d4d3b25 100644 --- a/clang/lib/CIR/CodeGen/CIRGenFunction.h +++ b/clang/lib/CIR/CodeGen/CIRGenFunction.h @@ -497,6 +497,12 @@ class CIRGenFunction : public CIRGenTypeCache { VlaSizePair getVLASize(const VariableArrayType *type); VlaSizePair getVLASize(QualType type); + Address getAsNaturalAddressOf(Address addr, QualType pointeeTy); + + mlir::Value getAsNaturalPointerTo(Address addr, QualType pointeeType) { + return getAsNaturalAddressOf(addr, pointeeType).getBasePointer(); + } + void finishFunction(SourceLocation endLoc); /// Determine whether the given initializer is trivial in the sense diff --git a/clang/lib/CIR/CodeGen/CIRGenPointerAuth.cpp b/clang/lib/CIR/CodeGen/CIRGenPointerAuth.cpp new file mode 100644 index 0000000000000..20b0646fdab44 --- /dev/null +++ b/clang/lib/CIR/CodeGen/CIRGenPointerAuth.cpp @@ -0,0 +1,23 @@ +//===--- CIRGenPointerAuth.cpp - CIR generation for ptr auth --------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file contains common routines relating to the emission of +// pointer authentication operations. +// +//===----------------------------------------------------------------------===// + +#include "CIRGenFunction.h" + +using namespace clang; +using namespace clang::CIRGen; + +Address CIRGenFunction::getAsNaturalAddressOf(Address addr, + QualType pointeeTy) { + assert(!cir::MissingFeatures::pointerAuthentication()); + return addr; +} diff --git a/clang/lib/CIR/CodeGen/CMakeLists.txt b/clang/lib/CIR/CodeGen/CMakeLists.txt index 7c31beacc5fb3..d3e2290ceea0b 100644 --- a/clang/lib/CIR/CodeGen/CMakeLists.txt +++ b/clang/lib/CIR/CodeGen/CMakeLists.txt @@ -35,6 +35,7 @@ add_clang_library(clangCIR CIRGenOpenACC.cpp CIRGenOpenACCClause.cpp CIRGenOpenACCRecipe.cpp + CIRGenPointerAuth.cpp CIRGenRecordLayoutBuilder.cpp CIRGenStmt.cpp CIRGenStmtOpenACC.cpp diff --git a/clang/test/CIR/CodeGen/derived-to-base.cpp b/clang/test/CIR/CodeGen/derived-to-base.cpp new file mode 100644 index 0000000000000..13acb47022c65 --- /dev/null +++ b/clang/test/CIR/CodeGen/derived-to-base.cpp @@ -0,0 +1,129 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir +// RUN: FileCheck --input-file=%t.cir %s --check-prefix=CIR +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --input-file=%t-cir.ll %s --check-prefix=LLVM +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.ll +// RUN: FileCheck --input-file=%t.ll %s --check-prefix=OGCG + +// TODO(cir): The constructors in this test case are only here because we don't +// have support for zero-initialization of base classes yet. We should +// fix that soon. + +struct Base { + Base(); + void f(); + int a; +}; + +struct Derived : Base { + Derived(); + double b; +}; + +void f() { + Derived d; + d.f(); +} + +// CIR: cir.func {{.*}} @_Z1fv() +// CIR: %[[D:.*]] = cir.alloca !rec_Derived, !cir.ptr<!rec_Derived>, ["d", init] +// CIR: cir.call @_ZN7DerivedC1Ev(%[[D]]) : (!cir.ptr<!rec_Derived>) -> () +// CIR: %[[D_BASE:.*]] = cir.base_class_addr %[[D]] : !cir.ptr<!rec_Derived> nonnull [0] -> !cir.ptr<!rec_Base> +// CIR: cir.call @_ZN4Base1fEv(%[[D_BASE]]) : (!cir.ptr<!rec_Base>) -> () + +// LLVM: define {{.*}}void @_Z1fv() +// LLVM: %[[D:.*]] = alloca %struct.Derived +// LLVM: call void @_ZN7DerivedC1Ev(ptr %[[D]]) +// LLVM: call void @_ZN4Base1fEv(ptr %[[D]]) + +// OGCG: define {{.*}}void @_Z1fv() +// OGCG: %[[D:.*]] = alloca %struct.Derived +// OGCG: call void @_ZN7DerivedC1Ev(ptr {{.*}} %[[D]]) +// OGCG: call void @_ZN4Base1fEv(ptr {{.*}} %[[D]]) + +void useBase(Base *base); +void callBaseUsingDerived(Derived *derived) { + useBase(derived); +} + + +// CIR: cir.func {{.*}} @_Z20callBaseUsingDerivedP7Derived(%[[DERIVED_ARG:.*]]: !cir.ptr<!rec_Derived> {{.*}}) +// CIR: %[[DERIVED_ADDR:.*]] = cir.alloca !cir.ptr<!rec_Derived>, !cir.ptr<!cir.ptr<!rec_Derived>>, ["derived", init] +// CIR: cir.store %[[DERIVED_ARG]], %[[DERIVED_ADDR]] +// CIR: %[[DERIVED:.*]] = cir.load{{.*}} %[[DERIVED_ADDR]] +// CIR: %[[DERIVED_BASE:.*]] = cir.base_class_addr %[[DERIVED]] : !cir.ptr<!rec_Derived> nonnull [0] -> !cir.ptr<!rec_Base> +// CIR: cir.call @_Z7useBaseP4Base(%[[DERIVED_BASE]]) : (!cir.ptr<!rec_Base>) -> () + +// LLVM: define {{.*}} void @_Z20callBaseUsingDerivedP7Derived(ptr %[[DERIVED_ARG:.*]]) +// LLVM: %[[DERIVED_ADDR:.*]] = alloca ptr +// LLVM: store ptr %[[DERIVED_ARG]], ptr %[[DERIVED_ADDR]] +// LLVM: %[[DERIVED:.*]] = load ptr, ptr %[[DERIVED_ADDR]] +// LLVM: call void @_Z7useBaseP4Base(ptr %[[DERIVED]]) + +// OGCG: define {{.*}} void @_Z20callBaseUsingDerivedP7Derived(ptr {{.*}} %[[DERIVED_ARG:.*]]) +// OGCG: %[[DERIVED_ADDR:.*]] = alloca ptr +// OGCG: store ptr %[[DERIVED_ARG]], ptr %[[DERIVED_ADDR]] +// OGCG: %[[DERIVED:.*]] = load ptr, ptr %[[DERIVED_ADDR]] +// OGCG: call void @_Z7useBaseP4Base(ptr {{.*}} %[[DERIVED]]) + +Base *returnBaseFromDerived(Derived* derived) { + return derived; +} + +// CIR: cir.func {{.*}} @_Z21returnBaseFromDerivedP7Derived(%[[DERIVED_ARG:.*]]: !cir.ptr<!rec_Derived> {{.*}}) -> !cir.ptr<!rec_Base> +// CIR: %[[DERIVED_ADDR:.*]] = cir.alloca !cir.ptr<!rec_Derived>, !cir.ptr<!cir.ptr<!rec_Derived>>, ["derived", init] +// CIR: %[[BASE_ADDR:.*]] = cir.alloca !cir.ptr<!rec_Base>, !cir.ptr<!cir.ptr<!rec_Base>>, ["__retval"] +// CIR: cir.store %[[DERIVED_ARG]], %[[DERIVED_ADDR]] +// CIR: %[[DERIVED:.*]] = cir.load{{.*}} %[[DERIVED_ADDR]] +// CIR: %[[DERIVED_BASE:.*]] = cir.base_class_addr %[[DERIVED]] : !cir.ptr<!rec_Derived> nonnull [0] -> !cir.ptr<!rec_Base> +// CIR: cir.store %[[DERIVED_BASE]], %[[BASE_ADDR]] +// CIR: %[[BASE:.*]] = cir.load{{.*}} %[[BASE_ADDR]] +// CIR: cir.return %[[BASE]] : !cir.ptr<!rec_Base> + +// LLVM: define {{.*}} ptr @_Z21returnBaseFromDerivedP7Derived(ptr %[[DERIVED_ARG:.*]]) +// LLVM: %[[DERIVED_ADDR:.*]] = alloca ptr +// LLVM: store ptr %[[DERIVED_ARG]], ptr %[[DERIVED_ADDR]] +// LLVM: %[[DERIVED:.*]] = load ptr, ptr %[[DERIVED_ADDR]] + +// OGCG: define {{.*}} ptr @_Z21returnBaseFromDerivedP7Derived(ptr {{.*}} %[[DERIVED_ARG:.*]]) +// OGCG: %[[DERIVED_ADDR:.*]] = alloca ptr +// OGCG: store ptr %[[DERIVED_ARG]], ptr %[[DERIVED_ADDR]] +// OGCG: %[[DERIVED:.*]] = load ptr, ptr %[[DERIVED_ADDR]] + +volatile Derived derivedObj; + +void test_volatile_store() { + derivedObj.a = 0; +} + +// CIR: cir.func {{.*}} @_Z19test_volatile_storev() +// CIR: %[[ZERO:.*]] = cir.const #cir.int<0> : !s32i +// CIR: %[[DERIVED_OBJ:.*]] = cir.get_global @derivedObj : !cir.ptr<!rec_Derived> +// CIR: %[[DERIVED_OBJ_BASE:.*]] = cir.base_class_addr %[[DERIVED_OBJ]] : !cir.ptr<!rec_Derived> nonnull [0] -> !cir.ptr<!rec_Base> +// CIR: %[[DERIVED_OBJ_A:.*]] = cir.get_member %[[DERIVED_OBJ_BASE]][0] {name = "a"} : !cir.ptr<!rec_Base> -> !cir.ptr<!s32i> +// CIR: cir.store volatile {{.*}} %[[ZERO]], %[[DERIVED_OBJ_A]] : !s32i, !cir.ptr<!s32i> + +// LLVM: define {{.*}} void @_Z19test_volatile_storev() +// LLVM: store volatile i32 0, ptr @derivedObj + +// OGCG: define {{.*}} void @_Z19test_volatile_storev() +// OGCG: store volatile i32 0, ptr @derivedObj + +void test_volatile_load() { + [[maybe_unused]] int val = derivedObj.a; +} + +// CIR: cir.func {{.*}} @_Z18test_volatile_loadv() +// CIR: %[[DERIVED_OBJ:.*]] = cir.get_global @derivedObj : !cir.ptr<!rec_Derived> +// CIR: %[[DERIVED_OBJ_BASE:.*]] = cir.base_class_addr %[[DERIVED_OBJ]] : !cir.ptr<!rec_Derived> nonnull [0] -> !cir.ptr<!rec_Base> +// CIR: %[[DERIVED_OBJ_A:.*]] = cir.get_member %[[DERIVED_OBJ_BASE]][0] {name = "a"} : !cir.ptr<!rec_Base> -> !cir.ptr<!s32i> +// CIR: %[[VAL:.*]] = cir.load volatile {{.*}} %[[DERIVED_OBJ_A]] : !cir.ptr<!s32i>, !s32i + +// LLVM: define {{.*}} void @_Z18test_volatile_loadv() +// LLVM: %[[VAL_ADDR:.*]] = alloca i32 +// LLVM: %[[DERIVED_OBJ:.*]] = load volatile i32, ptr @derivedObj + +// OGCG: define {{.*}} void @_Z18test_volatile_loadv() +// OGCG: %[[VAL_ADDR:.*]] = alloca i32 +// OGCG: %[[DERIVED_OBJ:.*]] = load volatile i32, ptr @derivedObj +// OGCG: store i32 %[[DERIVED_OBJ]], ptr %[[VAL_ADDR]] _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
