Author: adams381 Date: 2026-06-23T12:47:22-05:00 New Revision: 87789e236d9de4b8d688a0d7291c7390fc2c58b4
URL: https://github.com/llvm/llvm-project/commit/87789e236d9de4b8d688a0d7291c7390fc2c58b4 DIFF: https://github.com/llvm/llvm-project/commit/87789e236d9de4b8d688a0d7291c7390fc2c58b4.diff LOG: [CIR] Handle non-zero-initializable types in emitNullInitialization (#201654) Value-initializing an aggregate containing a pointer-to-data-member (e.g. `new Inner()` where `Inner` has an `int Inner::*` field) crashed with "type is not zero initializable" because `emitNullInitialization` unconditionally called `errorNYI` for types where `isZeroInitializable` returns false. Member pointers use -1 as the null sentinel, so a plain zero store is incorrect. Replace the `errorNYI` with `emitNullConstant`, which already builds the correct per-field pattern (-1 for member-pointer fields, zero elsewhere), and store the result. Types with virtual bases are still guarded with `errorNYI` since `emitNullConstant` does not yet handle them. Added: clang/test/CIR/CodeGen/member-pointer-null-init.cpp Modified: clang/lib/CIR/CodeGen/CIRGenFunction.cpp Removed: ################################################################################ diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp index 4b020c96964a7..6606cf74c7dea 100644 --- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp @@ -1385,7 +1385,15 @@ void CIRGenFunction::emitNullInitialization(mlir::Location loc, Address destPtr, // TODO: there are other patterns besides zero that we can usefully memset, // like -1, which happens to be the pattern used by member-pointers. if (!cgm.getTypes().isZeroInitializable(ty)) { - cgm.errorNYI(loc, "type is not zero initializable"); + // Only the pointer-to-data-member case is tested here; emitNullConstant + // owns the NYIs for shapes it cannot build (virtual bases, non-zero-init + // arrays). + assert((ty->isMemberDataPointerType() || ty->isRecordType()) && + "emitNullInitialization: only pointer-to-data-member (directly or " + "within a record) null initialization is implemented"); + mlir::Value nullVal = cgm.emitNullConstant(ty, loc); + builder.createStore(loc, nullVal, destPtr); + return; } // In LLVM Codegen: otherwise, just memset the whole thing to zero using diff --git a/clang/test/CIR/CodeGen/member-pointer-null-init.cpp b/clang/test/CIR/CodeGen/member-pointer-null-init.cpp new file mode 100644 index 0000000000000..74ee344c6f407 --- /dev/null +++ b/clang/test/CIR/CodeGen/member-pointer-null-init.cpp @@ -0,0 +1,47 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -fclangir -emit-cir %s -o %t.cir +// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -fclangir -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --check-prefix=LLVM,LLVMCIR --input-file=%t-cir.ll %s +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++17 -emit-llvm %s -o %t.ll +// RUN: FileCheck --check-prefix=LLVM,OGCG --input-file=%t.ll %s + +struct Inner { + int Inner::*p; +}; + +struct Outer { + Inner a; + int b; +}; + +// Value-init of a heap-allocated struct containing a pointer-to-data-member. +// The member pointer is null (-1), so the stored constant must carry -1. + +// CIR-LABEL: cir.func {{.*}}@_Z8make_newv +// CIR: [[NULL:%.*]] = cir.const #cir.const_record<{#cir.int<-1> : !s64i}> : !rec_Inner +// CIR: cir.store align(8) [[NULL]], {{%.*}} : !rec_Inner, !cir.ptr<!rec_Inner> + +// LLVMCIR-LABEL: define {{.*}} ptr @_Z8make_newv +// LLVMCIR: call {{.*}} @_Znwm +// LLVMCIR: store %struct.Inner { i64 -1 }, ptr %{{.*}}, align 8 + +// OGCG: @{{.*}} = private constant %struct.Inner { i64 -1 } +// OGCG-LABEL: define {{.*}} ptr @_Z8make_newv +// OGCG: call {{.*}} @llvm.memcpy{{.*}}i64 8 + +Inner *make_new() { return new Inner(); } + +// Partial aggregate init: Inner subobject 'a' is value-initialized because +// it has no designated initializer. + +// CIR-LABEL: cir.func {{.*}}@_Z11runtime_aggi +// CIR: cir.const #cir.int<-1> : !s64i +// CIR: cir.store align(8) {{%.*}}, {{%.*}} : !s64i + +// LLVM-LABEL: define {{.*}} void @_Z11runtime_aggi +// LLVM: store i64 -1, ptr %{{.*}}, align 8 + +void runtime_agg(int x) { + Outer o = {.b = x}; + (void)o; +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
