[Lldb-commits] [lldb] r360024 - Revert r359949 "[clang] adding explicit(bool) from c++2a"

[Hans Wennborg via lldb-commits]

Author: hans
Date: Mon May  6 02:51:10 2019
New Revision: 360024

URL: http://llvm.org/viewvc/llvm-project?rev=360024&view=rev
Log:
Revert r359949 "[clang] adding explicit(bool) from c++2a"

This caused Clang to start erroring on the following:

  struct S {
    template <typename = int> explicit S();
  };

  struct T : S {};

  struct U : T {
    U();
  };
  U::U() {}

  $ clang -c /tmp/x.cc
  /tmp/x.cc:10:4: error: call to implicitly-deleted default constructor of 'T'
  U::U() {}
     ^
  /tmp/x.cc:5:12: note: default constructor of 'T' is implicitly deleted
    because base class 'S' has no default constructor
  struct T : S {};
             ^
  1 error generated.

See discussion on the cfe-commits email thread.

This also reverts the follow-ups r359966 and r359968.

> this patch adds support for the explicit bool specifier.
>
> Changes:
> - The parsing for the explicit(bool) specifier was added in ParseDecl.cpp.
> - The storage of the explicit specifier was changed. the explicit specifier was stored as a boolean value in the FunctionDeclBitfields and in the DeclSpec class. now it is stored as a PointerIntPair<Expr*, 2> with a flag and a potential expression in CXXConstructorDecl, CXXDeductionGuideDecl, CXXConversionDecl and in the DeclSpec class.
> - Following the AST change, Serialization, ASTMatchers, ASTComparator and ASTPrinter were adapted.
> - Template instantiation was adapted to instantiate the potential expressions of the explicit(bool) specifier When instantiating their associated declaration.
> - The Add*Candidate functions were adapted, they now take a Boolean indicating if the context allowing explicit constructor or conversion function and this boolean is used to remove invalid overloads that required template instantiation to be detected.
> - Test for Semantic and Serialization were added.
>
> This patch is not yet complete. I still need to check that interaction with CTAD and deduction guides is correct. and add more tests for AST operations. But I wanted first feedback.
> Perhaps this patch should be spited in smaller patches, but making each patch testable as a standalone may be tricky.
>
> Patch by Tyker
>
> Differential Revision: https://reviews.llvm.org/D60934

Modified:
    lldb/trunk/source/Symbol/ClangASTContext.cpp

Modified: lldb/trunk/source/Symbol/ClangASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Symbol/ClangASTContext.cpp?rev=360024&r1=360023&r2=360024&view=diff
==============================================================================
--- lldb/trunk/source/Symbol/ClangASTContext.cpp (original)
+++ lldb/trunk/source/Symbol/ClangASTContext.cpp Mon May  6 02:51:10 2019
@@ -8167,10 +8167,6 @@ clang::CXXMethodDecl *ClangASTContext::A
   if (is_artificial)
     return nullptr; // skip everything artificial
 
-  const clang::ExplicitSpecifier explicit_spec(
-      nullptr /*expr*/, is_explicit
-                            ? clang::ExplicitSpecKind::ResolvedTrue
-                            : clang::ExplicitSpecKind::ResolvedFalse);
   if (name[0] == '~') {
     cxx_dtor_decl = clang::CXXDestructorDecl::Create(
         *getASTContext(), cxx_record_decl, clang::SourceLocation(),
@@ -8189,7 +8185,7 @@ clang::CXXMethodDecl *ClangASTContext::A
             clang::SourceLocation()),
         method_qual_type,
         nullptr, // TypeSourceInfo *
-        explicit_spec, is_inline, is_artificial, false /*is_constexpr*/);
+        is_explicit, is_inline, is_artificial, false /*is_constexpr*/);
     cxx_method_decl = cxx_ctor_decl;
   } else {
     clang::StorageClass SC = is_static ? clang::SC_Static : clang::SC_None;
@@ -8224,7 +8220,7 @@ clang::CXXMethodDecl *ClangASTContext::A
                 clang::SourceLocation()),
             method_qual_type,
             nullptr, // TypeSourceInfo *
-            is_inline, explicit_spec, false /*is_constexpr*/,
+            is_inline, is_explicit, false /*is_constexpr*/,
             clang::SourceLocation());
       }
     }