[clang] 1bc7f3f - [Clang] Fix a crash when trying to initialize an invalid aggregate.

[Corentin Jabot via cfe-commits]

Author: Corentin Jabot
Date: 2023-07-05T15:45:46+02:00
New Revision: 1bc7f3fb936724dd7a2d0b5ac91f773d3168a5f0

URL: https://github.com/llvm/llvm-project/commit/1bc7f3fb936724dd7a2d0b5ac91f773d3168a5f0
DIFF: https://github.com/llvm/llvm-project/commit/1bc7f3fb936724dd7a2d0b5ac91f773d3168a5f0.diff

LOG: [Clang] Fix a crash when trying to initialize an invalid aggregate.

We did not return an error when failing to producing
a valid expression when performing the initialization of
an aggregate initialized with a parenthesized list of expressions.

This is a regression introduced in Clang 17.

Fixes #63278

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D154486

Added: 
    

Modified: 
    clang/lib/Sema/SemaInit.cpp
    clang/test/SemaCXX/paren-list-agg-init.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index b893d358dfe790..6db211a20e311f 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -9387,10 +9387,13 @@ ExprResult InitializationSequence::Perform(Sema &S,
     }
   }
 
+  Expr *Init = CurInit.get();
+  if (!Init)
+    return ExprError();
+
   // Check whether the initializer has a shorter lifetime than the initialized
   // entity, and if not, either lifetime-extend or warn as appropriate.
-  if (auto *Init = CurInit.get())
-    S.checkInitializerLifetime(Entity, Init);
+  S.checkInitializerLifetime(Entity, Init);
 
   // Diagnose non-fatal problems with the completed initialization.
   if (InitializedEntity::EntityKind EK = Entity.getKind();
@@ -9398,16 +9401,13 @@ ExprResult InitializationSequence::Perform(Sema &S,
        EK == InitializedEntity::EK_ParenAggInitMember) &&
       cast<FieldDecl>(Entity.getDecl())->isBitField())
     S.CheckBitFieldInitialization(Kind.getLocation(),
-                                  cast<FieldDecl>(Entity.getDecl()),
-                                  CurInit.get());
+                                  cast<FieldDecl>(Entity.getDecl()), Init);
 
   // Check for std::move on construction.
-  if (const Expr *E = CurInit.get()) {
-    CheckMoveOnConstruction(S, E,
-                            Entity.getKind() == InitializedEntity::EK_Result);
-  }
+  CheckMoveOnConstruction(S, Init,
+                          Entity.getKind() == InitializedEntity::EK_Result);
 
-  return CurInit;
+  return Init;
 }
 
 /// Somewhere within T there is an uninitialized reference subobject.

diff  --git a/clang/test/SemaCXX/paren-list-agg-init.cpp b/clang/test/SemaCXX/paren-list-agg-init.cpp
index 042ce3b3ddce2c..88d9b95c0e4be4 100644
--- a/clang/test/SemaCXX/paren-list-agg-init.cpp
+++ b/clang/test/SemaCXX/paren-list-agg-init.cpp
@@ -272,3 +272,25 @@ auto a = new A('a', {1.1});
 // expected-warning at -1 {{braces around scalar init}}
 // beforecxx20-warning at -2 {{aggregate initialization of type 'A' from a parenthesized list of values is a C++20 extension}}
 }
+
+
+namespace GH63278 {
+struct S {
+  int a = 0;
+  int b {0};
+  auto x = 1; // expected-error {{'auto' not allowed in non-static struct member}}
+  static const auto y = 1;
+};
+
+int test() {
+  // used to crash
+  S a(0, 1);
+  S b(0);
+  S c(0, 0, 1); // beforecxx20-warning {{aggregate initialization of type 'S' from a parenthesized list of values is a C++20 extension}}
+
+  S d {0, 1};
+  S e {0};
+  S f {0, 0, 1};
+}
+
+}