r295114 - Improve diagnostic reporting when using __declspec without enabling __declspec as a keyword.

[Mikael Holmén via cfe-commits]

Hi Aaron,


On 02/14/2017 11:47 PM, Aaron Ballman via cfe-commits wrote:
> Author: aaronballman
> Date: Tue Feb 14 16:47:20 2017
> New Revision: 295114
>
> URL: http://llvm.org/viewvc/llvm-project?rev=295114&view=rev
> Log:
> Improve diagnostic reporting when using __declspec without enabling __declspec as a keyword.
>
> Fixes PR31936.
>
> Added:
>     cfe/trunk/test/Parser/declspec-recovery.c
>     cfe/trunk/test/Parser/declspec-supported.c
> Modified:
>     cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
>     cfe/trunk/lib/Parse/ParseDecl.cpp
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td?rev=295114&r1=295113&r2=295114&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td Tue Feb 14 16:47:20 2017
> @@ -176,6 +176,9 @@ def warn_gcc_attribute_location : Warnin
>  def warn_attribute_no_decl : Warning<
>    "attribute %0 ignored, because it is not attached to a declaration">,
>    InGroup<IgnoredAttributes>;
> +def err_ms_attributes_not_enabled : Error<
> +  "'__declspec' attributes are not enabled; use '-fdeclspec' or "
> +  "'-fms-extensions' to enable support for __declspec attributes">;
>  def err_expected_method_body : Error<"expected method body">;
>  def err_declspec_after_virtspec : Error<
>    "'%0' qualifier may not appear after the virtual specifier '%1'">;
>
> Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=295114&r1=295113&r2=295114&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
> +++ cfe/trunk/lib/Parse/ParseDecl.cpp Tue Feb 14 16:47:20 2017
> @@ -2966,6 +2966,31 @@ void Parser::ParseDeclarationSpecifiers(
>        if (DS.hasTypeSpecifier())
>          goto DoneWithDeclSpec;
>
> +      // If the token is an identifier named "__declspec" and Microsoft
> +      // extensions are not enabled, it is likely that there will be cascading
> +      // parse errors if this really is a __declspec attribute. Attempt to
> +      // recognize that scenario and recover gracefully.
> +      if (!getLangOpts().DeclSpecKeyword && Tok.is(tok::identifier) &&
> +          Tok.getIdentifierInfo()->getName().equals("__declspec")) {
> +        Diag(Loc, diag::err_ms_attributes_not_enabled);
> +
> +        // The next token should be an open paren. If it is, eat the entire
> +        // attribute declaration and continue.
> +        if (NextToken().is(tok::l_paren)) {
> +          // Consume the __declspec identifier.
> +          SourceLocation Loc = ConsumeToken();

I get a warning about Loc not being used here:

../tools/clang/lib/Parse/ParseDecl.cpp:2981:26: error: unused variable 
'Loc' [-Werror,-Wunused-variable]
           SourceLocation Loc = ConsumeToken();

Regards,
Mikael

> +
> +          // Eat the parens and everything between them.
> +          BalancedDelimiterTracker T(*this, tok::l_paren);
> +          if (T.consumeOpen()) {
> +            assert(false && "Not a left paren?");
> +            return;
> +          }
> +          T.skipToEnd();
> +          continue;
> +        }
> +      }
> +
>        // In C++, check to see if this is a scope specifier like foo::bar::, if
>        // so handle it as such.  This is important for ctor parsing.
>        if (getLangOpts().CPlusPlus) {
>
> Added: cfe/trunk/test/Parser/declspec-recovery.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/declspec-recovery.c?rev=295114&view=auto
> ==============================================================================
> --- cfe/trunk/test/Parser/declspec-recovery.c (added)
> +++ cfe/trunk/test/Parser/declspec-recovery.c Tue Feb 14 16:47:20 2017
> @@ -0,0 +1,8 @@
> +// RUN: %clang_cc1 -triple i386-pc-unknown -fsyntax-only -verify %s
> +
> +__declspec(naked) void f(void) {} // expected-error{{'__declspec' attributes are not enabled; use '-fdeclspec' or '-fms-extensions' to enable support for __declspec attributes}}
> +
> +struct S {
> +  __declspec(property(get=Getter, put=Setter)) int X; // expected-error{{'__declspec' attributes are not enabled; use '-fdeclspec' or '-fms-extensions' to enable support for __declspec attributes}}
> +  int Y;
> +};
>
> Added: cfe/trunk/test/Parser/declspec-supported.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/declspec-supported.c?rev=295114&view=auto
> ==============================================================================
> --- cfe/trunk/test/Parser/declspec-supported.c (added)
> +++ cfe/trunk/test/Parser/declspec-supported.c Tue Feb 14 16:47:20 2017
> @@ -0,0 +1,10 @@
> +// RUN: %clang_cc1 -triple i386-pc-unknown -fsyntax-only -fms-extensions -verify %s
> +// RUN: %clang_cc1 -triple i386-pc-unknown -fsyntax-only -fdeclspec -verify %s
> +// expected-no-diagnostics
> +
> +__declspec(naked) void f(void) {}
> +
> +struct S {
> +  __declspec(property(get=Getter, put=Setter)) int X;
> +  int Y;
> +};
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>