[PATCH] D142534: [clang][codegen] Fix emission of consteval constructor of derived type

[Mariya Podchishchaeva via Phabricator via cfe-commits]

Fznamznon updated this revision to Diff 495851.
Fznamznon added a comment.

Rebase and add a release note


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142534/new/

https://reviews.llvm.org/D142534

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/CodeGen/CGExprAgg.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
@@ -92,3 +92,27 @@
 }
 } // namespace Issue55065
 
+namespace GH60166 {
+
+struct Base {
+   void* one = nullptr;
+   void* two = nullptr;
+};
+
+struct Derived : Base {
+   void* three = nullptr;
+   consteval Derived() = default;
+};
+
+void method() {
+  // CHECK: %agg.tmp.ensured = alloca %"struct.GH60166::Derived"
+  // CHECK: %0 = getelementptr inbounds { ptr, ptr, ptr }, ptr %agg.tmp.ensured, i32 0, i32 0
+  // CHECK: store ptr null, ptr %0, align 8
+  // CHECK: %1 = getelementptr inbounds { ptr, ptr, ptr }, ptr %agg.tmp.ensured, i32 0, i32 1
+  // CHECK: store ptr null, ptr %1, align 8
+  // CHECK: %2 = getelementptr inbounds { ptr, ptr, ptr }, ptr %agg.tmp.ensured, i32 0, i32 2
+  // CHECK: store ptr null, ptr %2, align 8
+   (void)Derived();
+}
+
+} // namespace GH60166
Index: clang/lib/CodeGen/CGExprAgg.cpp
===================================================================
--- clang/lib/CodeGen/CGExprAgg.cpp
+++ clang/lib/CodeGen/CGExprAgg.cpp
@@ -131,7 +131,14 @@
     EnsureDest(E->getType());
 
     if (llvm::Value *Result = ConstantEmitter(CGF).tryEmitConstantExpr(E)) {
-      CGF.EmitAggregateStore(Result, Dest.getAddress(),
+      Address StoreDest = Dest.getAddress();
+      // The emitted value is guaranteed to have the same size as the
+      // destination but can have a different type. Just do a bitcast in this
+      // case to avoid incorrect GEPs.
+      if (Result->getType() != StoreDest.getType())
+        StoreDest =
+            CGF.Builder.CreateElementBitCast(StoreDest, Result->getType());
+      CGF.EmitAggregateStore(Result, StoreDest,
                              E->getType().isVolatileQualified());
       return;
     }
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -64,6 +64,9 @@
   driver mode and emit an error which suggests using ``/TC`` or ``/TP``
   ``clang-cl`` options instead. This fixes
   `Issue 59307 <https://github.com/llvm/llvm-project/issues/59307>`_.
+- Fix crash when evaluating consteval constructor of derived class whose base
+  has more than one field. This fixes
+  `Issue 60166 <https://github.com/llvm/llvm-project/issues/60166>`_.
 
 Improvements to Clang's diagnostics
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


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