Commit Graph

2 Commits

Author SHA1 Message Date
Douglas Gregor 20c38a7c58 Improve recovery when we see a dependent template name that is missing
the required "template" keyword, using the same heuristics we do for
dependent template names in member access expressions, e.g.,

test/SemaTemplate/dependent-template-recover.cpp:11:8: error: use 'template'
      keyword to treat 'getAs' as a dependent template name
    T::getAs<U>();
       ^
       template 

Fixes PR5404.

llvm-svn: 104409
2010-05-21 23:43:39 +00:00
Douglas Gregor 786123dc48 Improve parser recovery when we encounter a dependent template name
that is missing the 'template' keyword, e.g., 

  t->getAs<T>()

where getAs is a member of an unknown specialization. C++ requires
that we treat "getAs" as a value, but that would fail to parse since T
is the name of a type. We would then fail at the '>', since a type
cannot be followed by a '>'.

This is a very common error for C++ programmers to make, especially
since GCC occasionally allows it when it shouldn't (as does Visual
C++). So, when we are in this case, we use tentative parsing to see if
the tokens starting at "<" can only be parsed as a template argument
list. If so, we produce a diagnostic with a fix-it that states that
the 'template' keyword is needed:

test/SemaTemplate/dependent-template-recover.cpp:5:8: error: 'template' keyword
      is required to treat 'getAs' as a dependent template name
    t->getAs<T>();
       ^
       template 

This is just a start of this patch; I'd like to apply the same
approach to everywhere that a template-id with dependent template name
can be parsed.

llvm-svn: 104406
2010-05-21 23:18:07 +00:00