[PATCH] D141690: [clang] fix consteval ctor code generation assert

[Luke Nihlen via Phabricator via cfe-commits]

luken-google updated this revision to Diff 489058.
luken-google added a comment.

Add newline at end of test file.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D141690/new/

https://reviews.llvm.org/D141690

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/CodeGen/CGCall.cpp
  clang/test/CodeGenCXX/cxx20-consteval-crash.cpp


Index: clang/test/CodeGenCXX/cxx20-consteval-crash.cpp
===================================================================
--- clang/test/CodeGenCXX/cxx20-consteval-crash.cpp
+++ clang/test/CodeGenCXX/cxx20-consteval-crash.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 %s -emit-llvm -o - | FileCheck %s
-// RUN: %clang_cc1 -emit-obj -debug-info-kind=constructor -std=c++20 %s -o -
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -fexceptions -fcxx-exceptions %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -emit-obj -debug-info-kind=constructor -std=c++20 -fexceptions -fcxx-exceptions %s -o -
 
 namespace PR50787 {
 // This code would previously cause a crash.
@@ -92,3 +92,41 @@
 }
 } // namespace Issue55065
 
+namespace Issue53983 {
+// This code would previously cause a crash in code generation
+// for the `bar` element in the `MyStruct` constructor.
+struct Base {
+    constexpr Base() : a(), b() {}
+    char a : 1;
+    char b;
+};
+
+struct Foo : private Base {
+    constexpr Foo(bool b) {
+        if (b) throw "test";
+    }
+};
+
+struct Bar : private Base {
+    consteval Bar(bool) {}
+};
+
+struct MyStruct {
+    Foo foo = true;
+    Bar bar = false;
+};
+MyStruct structTest;
+
+// clang should issue a constructor for MyStruct that calls Foo and Bar,
+// and a constructor for Bar that calls Base.
+// CHECK: define{{.*}} void @_ZN10Issue539838MyStructC2Ev(
+// CHECK: entry:
+// CHECK: call void @_ZN10Issue539833FooC2Eb(
+// CHECK: call void @_ZN10Issue539833BarC2Eb(
+// CHECK: ret void
+
+// CHECK: define{{.*}} void @_ZN10Issue539833BarC2Eb(
+// CHECK: entry:
+// CHECK: call void @_ZN10Issue539834BaseC2Ev(
+// CHECK: ret void
+} // namespace Issue53983
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -1334,7 +1334,8 @@
 void CodeGenFunction::EmitAggregateStore(llvm::Value *Val, Address Dest,
                                          bool DestIsVolatile) {
   // Prefer scalar stores to first-class aggregate stores.
-  if (llvm::StructType *STy = dyn_cast<llvm::StructType>(Val->getType())) {
+  llvm::StructType *STy = dyn_cast<llvm::StructType>(Val->getType());
+  if (STy && STy->canLosslesslyBitCastTo(Dest.getElementType())) {
     for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
       Address EltPtr = Builder.CreateStructGEP(Dest, i);
       llvm::Value *Elt = Builder.CreateExtractValue(Val, i);
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -739,6 +739,8 @@
   which specifies constrained lambdas and constrained template *template-parameter*\s.
 - Required parameter pack to be provided at the end of the concept parameter list. This
   fixes `Issue 48182 <https://github.com/llvm/llvm-project/issues/48182>`_.
+- Fixed a assert triggered in some cases of a ``consteval`` implicit cast constructor. Fixes
+  `Issue 53983 <https://github.com/llvm/llvm-project/issues/53983>`_.
 
 - Do not hide templated base members introduced via using-decl in derived class
   (useful specially for constrained members). Fixes `GH50886 <https://github.com/llvm/llvm-project/issues/50886>`_.


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