[clang] 32d7aae - [clang] Fix a clang crash on invalid code in C++20 mode.

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2022-12-23T12:40:39+01:00
New Revision: 32d7aae04fdb58e65a952f281ff2f2c3f396d98f

URL: https://github.com/llvm/llvm-project/commit/32d7aae04fdb58e65a952f281ff2f2c3f396d98f
DIFF: https://github.com/llvm/llvm-project/commit/32d7aae04fdb58e65a952f281ff2f2c3f396d98f.diff

LOG: [clang] Fix a clang crash on invalid code in C++20 mode.

This crash is a combination of recovery-expr + new SemaInit.cpp code
introduced by by https://reviews.llvm.org/D129531.

Differential Revision: https://reviews.llvm.org/D140587

Added: 
    

Modified: 
    clang/lib/Sema/SemaInit.cpp
    clang/test/SemaCXX/recovery-expr-type.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 103986521f76e..efc3274ce7d3c 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -6176,7 +6176,11 @@ void InitializationSequence::InitializeFrom(Sema &S,
       // constructors. For example, conversion function.
       if (const auto *RD =
               dyn_cast<CXXRecordDecl>(DestType->getAs<RecordType>()->getDecl());
-          S.getLangOpts().CPlusPlus20 && RD && RD->isAggregate() && Failed() &&
+          // In general, we should call isCompleteType for RD to check its
+          // completeness, we don't call it here as it was already called in the
+          // above TryConstructorInitialization.
+          S.getLangOpts().CPlusPlus20 && RD && RD->hasDefinition() &&
+          RD->isAggregate() && Failed() &&
           getFailureKind() == FK_ConstructorOverloadFailed) {
         // C++20 [dcl.init] 17.6.2.2:
         //   - Otherwise, if no constructor is viable, the destination type is

diff  --git a/clang/test/SemaCXX/recovery-expr-type.cpp b/clang/test/SemaCXX/recovery-expr-type.cpp
index a5ba1ae2b8222..479039f284799 100644
--- a/clang/test/SemaCXX/recovery-expr-type.cpp
+++ b/clang/test/SemaCXX/recovery-expr-type.cpp
@@ -1,4 +1,6 @@
-// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -frecovery-ast -frecovery-ast-type -o - %s -std=gnu++17 -fsyntax-only -verify
+// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -o - %s -std=gnu++17 -fsyntax-only -verify
+// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -o - %s -std=gnu++20 -fsyntax-only -verify
+
 
 namespace test0 {
 struct Indestructible {
@@ -171,3 +173,13 @@ void f() {
   S.m(1); // no crash
 }
 }
+
+namespace test16 {
+// verify we do not crash on incomplete class type.
+template<typename T, typename U> struct A; // expected-note 5{{template is declared here}}
+A<int, int> foo() { // expected-error {{implicit instantiation of undefined template}}
+  if (1 == 1)
+    return A<int, int>{1}; // expected-error 2{{implicit instantiation of undefined template}}
+  return A<int, int>(1); // expected-error 2{{implicit instantiation of undefined template}}
+}
+}