[clang] eed0af6 - [clang] Exclude invalid destructors from lookups.

[Adam Czachorowski via cfe-commits]

Author: Adam Czachorowski
Date: 2020-08-26T19:29:30+02:00
New Revision: eed0af6179ca4fe9e60121e0829ed8d3849b1ce5

URL: https://github.com/llvm/llvm-project/commit/eed0af6179ca4fe9e60121e0829ed8d3849b1ce5
DIFF: https://github.com/llvm/llvm-project/commit/eed0af6179ca4fe9e60121e0829ed8d3849b1ce5.diff

LOG: [clang] Exclude invalid destructors from lookups.

This fixes a crash when declaring a destructor with a wrong name, then
writing result to pch file and loading it again. The PCH storage uses
DeclarationNameKey as key and it is the same key for both the invalid
destructor and the implicit one that was created because the other one
was invalid. When querying for the Foo::~Foo we end up getting
Foo::~Bar, which is then rejected and we end up with nullptr in
CXXRecordDecl::GetDestructor().

Fixes https://bugs.llvm.org/show_bug.cgi?id=47270

Differential Revision: https://reviews.llvm.org/D86624

Added: 
    clang/test/PCH/cxx-invalid-destructor.cpp
    clang/test/PCH/cxx-invalid-destructor.h

Modified: 
    clang/lib/AST/DeclBase.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index da1eadd9d931d..f4314d0bd9614 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -1487,6 +1487,13 @@ static bool shouldBeHidden(NamedDecl *D) {
     if (FD->isFunctionTemplateSpecialization())
       return true;
 
+  // Hide destructors that are invalid. There should always be one destructor,
+  // but if it is an invalid decl, another one is created. We need to hide the
+  // invalid one from places that expect exactly one destructor, like the
+  // serialization code.
+  if (isa<CXXDestructorDecl>(D) && D->isInvalidDecl())
+    return true;
+
   return false;
 }
 

diff  --git a/clang/test/PCH/cxx-invalid-destructor.cpp b/clang/test/PCH/cxx-invalid-destructor.cpp
new file mode 100644
index 0000000000000..fc89cf1f3dfc1
--- /dev/null
+++ b/clang/test/PCH/cxx-invalid-destructor.cpp
@@ -0,0 +1,4 @@
+// RUN: %clang_cc1 -x c++ -std=c++11 -emit-pch -o %t %S/cxx-invalid-destructor.h -fallow-pch-with-compiler-errors
+// RUN: %clang_cc1 -x c++ -std=c++11 -include-pch %t %S/cxx-invalid-destructor.cpp -fsyntax-only -fno-validate-pch
+
+Foo f;

diff  --git a/clang/test/PCH/cxx-invalid-destructor.h b/clang/test/PCH/cxx-invalid-destructor.h
new file mode 100644
index 0000000000000..59095a37c203e
--- /dev/null
+++ b/clang/test/PCH/cxx-invalid-destructor.h
@@ -0,0 +1,7 @@
+struct Base {
+  ~Base();
+};
+
+struct Foo : public Base {
+  ~Base();
+};