[clang] 5d9889a - [clang][Interp] Fix zero-initializing records with non-trivial ctors

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-05-02T13:20:04+02:00
New Revision: 5d9889a6c6c97c92380c8eee48eaa35067f63766

URL: https://github.com/llvm/llvm-project/commit/5d9889a6c6c97c92380c8eee48eaa35067f63766
DIFF: https://github.com/llvm/llvm-project/commit/5d9889a6c6c97c92380c8eee48eaa35067f63766.diff

LOG: [clang][Interp] Fix zero-initializing records with non-trivial ctors

We need to do the zero-init and then subsequently call the constructor.

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeExprGen.cpp
    clang/test/AST/Interp/records.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index f1a51e81a92c2d..2dfa726cc75256 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -2095,10 +2095,16 @@ bool ByteCodeExprGen<Emitter>::VisitCXXConstructExpr(
   if (T->isRecordType()) {
     const CXXConstructorDecl *Ctor = E->getConstructor();
 
-    // Trivial zero initialization.
-    if (E->requiresZeroInitialization() && Ctor->isTrivial()) {
+    // Zero initialization.
+    if (E->requiresZeroInitialization()) {
       const Record *R = getRecord(E->getType());
-      return this->visitZeroRecordInitializer(R, E);
+
+      if (!this->visitZeroRecordInitializer(R, E))
+        return false;
+
+      // If the constructor is trivial anyway, we're done.
+      if (Ctor->isTrivial())
+        return true;
     }
 
     const Function *Func = getFunction(Ctor);

diff  --git a/clang/test/AST/Interp/records.cpp b/clang/test/AST/Interp/records.cpp
index 771e5adfca34a4..26efd6896a9f7e 100644
--- a/clang/test/AST/Interp/records.cpp
+++ b/clang/test/AST/Interp/records.cpp
@@ -999,10 +999,9 @@ namespace TemporaryObjectExpr {
       F f{12};
     };
     constexpr int foo(S x) {
-      return x.a; // expected-note {{read of uninitialized object}}
+      return x.a;
     }
-    static_assert(foo(S()) == 0, ""); // expected-error {{not an integral constant expression}} \
-                                      // expected-note {{in call to}}
+    static_assert(foo(S()) == 0, "");
   };
 #endif
 }
@@ -1425,6 +1424,11 @@ namespace ZeroInit {
   };
   constexpr S3 s3d; // both-error {{default initialization of an object of const type 'const S3' without a user-provided default constructor}}
   static_assert(s3d.n == 0, "");
+
+  struct P {
+    int a = 10;
+  };
+  static_assert(P().a == 10, "");
 }
 
 namespace {