[cfe-commits] r153488 - in /cfe/trunk: lib/Parse/ParseDecl.cpp test/Parser/cxx-class.cpp test/SemaCXX/copy-assignment.cpp

[Eli Friedman]

On Mon, Mar 26, 2012 at 5:56 PM, Richard Smith
<richard-llvm at metafoo.co.uk> wrote:
> Author: rsmith
> Date: Mon Mar 26 19:56:56 2012
> New Revision: 153488
>
> URL: http://llvm.org/viewvc/llvm-project?rev=153488&view=rev
> Log:
> When we see 'Class(X' or 'Class::Class(X' and we suspect that it names a
> constructor, but X is not a known typename, check whether the tokens could
> possibly match the syntax of a declarator before concluding that it isn't
> a constructor. If it's definitely ill-formed, assume it is a constructor.
>
> Empirical evidence suggests that this pattern is much more often a
> constructor with a typoed (or not-yet-declared) type name than any of the
> other possibilities, so the extra cost of the check is not expected to be
> problematic.
>
> Modified:
>    cfe/trunk/lib/Parse/ParseDecl.cpp
>    cfe/trunk/test/Parser/cxx-class.cpp
>    cfe/trunk/test/SemaCXX/copy-assignment.cpp
>
> Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=153488&r1=153487&r2=153488&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
> +++ cfe/trunk/lib/Parse/ParseDecl.cpp Mon Mar 26 19:56:56 2012
> @@ -3379,7 +3379,42 @@
>   // Check whether the next token(s) are part of a declaration
>   // specifier, in which case we have the start of a parameter and,
>   // therefore, we know that this is a constructor.
> -  bool IsConstructor = isDeclarationSpecifier();
> +  bool IsConstructor = false;
> +  if (isDeclarationSpecifier())
> +    IsConstructor = true;
> +  else if (Tok.is(tok::identifier) ||
> +           (Tok.is(tok::annot_cxxscope) && NextToken().is(tok::identifier))) {
> +    // We've seen "C ( X" or "C ( X::Y", but "X" / "X::Y" is not a type.
> +    // This might be a parenthesized member name, but is more likely to
> +    // be a constructor declaration with an invalid argument type. Keep
> +    // looking.
> +    if (Tok.is(tok::annot_cxxscope))
> +      ConsumeToken();
> +    ConsumeToken();
> +
> +    // If this is not a constructor, we must be parsing a declarator,
> +    // which must have one of the following syntactic forms:
> +    switch (Tok.getKind()) {
> +    case tok::l_paren:
> +      // C(X   (   int));
> +    case tok::l_square:
> +      // C(X   [   5]);
> +      // C(X   [   [attribute]]);
> +    case tok::coloncolon:
> +      // C(X   ::   Y);
> +      // C(X   ::   *p);
> +    case tok::r_paren:
> +      // C(X   )
> +      // Assume this isn't a constructor, rather than assuming it's a
> +      // constructor with an unnamed parameter of an ill-formed type.
> +      break;

I really don't like adding new lists of tokens like this... can you at
least leave a note pointing here from the place which actually handles
this grammar?

-Eli