[clang] 08128fe - [clang] Make member var invalid when static initializer is invalid.

[Adam Czachorowski via cfe-commits]

Author: Adam Czachorowski
Date: 2021-08-03T11:52:52+02:00
New Revision: 08128fe7059e20b3f97ae5abbdeff2e6f6c711ed

URL: https://github.com/llvm/llvm-project/commit/08128fe7059e20b3f97ae5abbdeff2e6f6c711ed
DIFF: https://github.com/llvm/llvm-project/commit/08128fe7059e20b3f97ae5abbdeff2e6f6c711ed.diff

LOG: [clang] Make member var invalid when static initializer is invalid.

Previously we would show an error, but keep the member, and also the
CXXRrecordDecl, valid. This could lead to crashes when attempting to
access the record layout or size.

Differential Revision: https://reviews.llvm.org/D105478

Added: 
    clang/test/AST/ast-dump-undeduced-expr.cpp

Modified: 
    clang/lib/Parse/ParseDeclCXX.cpp
    clang/test/SemaCXX/crash-auto-36064.cpp
    clang/test/SemaCXX/cxx11-crashes.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index ca5c013a51fe0..760600a3ea3ca 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -2989,9 +2989,11 @@ Parser::ParseCXXClassMemberDeclaration(AccessSpecifier AS,
       ExprResult Init = ParseCXXMemberInitializer(
           ThisDecl, DeclaratorInfo.isDeclarationOfFunction(), EqualLoc);
 
-      if (Init.isInvalid())
+      if (Init.isInvalid()) {
+        if (ThisDecl)
+          Actions.ActOnUninitializedDecl(ThisDecl);
         SkipUntil(tok::comma, StopAtSemi | StopBeforeMatch);
-      else if (ThisDecl)
+      } else if (ThisDecl)
         Actions.AddInitializerToDecl(ThisDecl, Init.get(), EqualLoc.isInvalid());
     } else if (ThisDecl && DS.getStorageClassSpec() == DeclSpec::SCS_static)
       // No initializer.

diff  --git a/clang/test/AST/ast-dump-undeduced-expr.cpp b/clang/test/AST/ast-dump-undeduced-expr.cpp
new file mode 100644
index 0000000000000..d404db9285974
--- /dev/null
+++ b/clang/test/AST/ast-dump-undeduced-expr.cpp
@@ -0,0 +1,7 @@
+// RUN: not %clang_cc1 -triple x86_64-unknown-unknown -ast-dump %s | FileCheck %s
+
+struct Foo {
+  static constexpr auto Bar = ;
+};
+
+// CHECK: -VarDecl {{.*}} invalid Bar 'const auto' static constexpr

diff  --git a/clang/test/SemaCXX/crash-auto-36064.cpp b/clang/test/SemaCXX/crash-auto-36064.cpp
index 5678cd8b730b8..a34e5eea51cb0 100644
--- a/clang/test/SemaCXX/crash-auto-36064.cpp
+++ b/clang/test/SemaCXX/crash-auto-36064.cpp
@@ -1,8 +1,9 @@
 // RUN: %clang_cc1 -fsyntax-only -std=c++11 %s -verify
-template <typename A, decltype(new A)> // expected-error{{new expression for type 'auto' requires a constructor argument}}
+template <typename A, decltype(new A)>
 struct b;
 struct d {
   static auto c = ;              // expected-error{{expected expression}}
+                                 // expected-error at -1 {{declaration of variable 'c' with deduced type 'auto' requires an initializer}}
+
   decltype(b<decltype(c), int>); // expected-error{{expected '(' for function-style cast or type construction}}
-                                 // expected-note at -1{{while substituting prior template arguments into non-type template parameter [with A = auto]}}
 };

diff  --git a/clang/test/SemaCXX/cxx11-crashes.cpp b/clang/test/SemaCXX/cxx11-crashes.cpp
index d60782df35f45..e63a9be956942 100644
--- a/clang/test/SemaCXX/cxx11-crashes.cpp
+++ b/clang/test/SemaCXX/cxx11-crashes.cpp
@@ -104,3 +104,22 @@ namespace pr29091 {
   bool baz() { return __has_nothrow_constructor(B); }
   bool qux() { return __has_nothrow_copy(B); }
 }
+
+namespace undeduced_field {
+template<class T>
+struct Foo {
+  typedef T type;
+};
+
+struct Bar {
+  Bar();
+  // The missing expression makes A undeduced.
+  static constexpr auto A = ;  // expected-error {{expected expression}}
+                               // expected-error at -1 {{declaration of variable 'A' with deduced type 'const auto' requires an initializer}}
+
+  Foo<decltype(A)>::type B;  // The type of B is also undeduced (wrapped in Elaborated).
+};
+
+// This used to crash when trying to get the layout of B.
+Bar x;
+}