Commit Graph

4 Commits

Author SHA1 Message Date
Richard Smith 17c59472e8 Improve error recovery for missing 'template' keyword in contexts where the
template is valid with or without it (with different meanings).

If we see "dependent.x<...", and what follows the '<' is a valid expression,
we must parse the '<' as a comparison rather than a template angle bracket.
When we later come to instantiate, if we find that the LHS of the '<' actually
names an overload set containing function templates, produce a diagnostic
suggesting that the 'template' keyword was missed rather than producing a
mysterious diagnostic saying that the function must be called (and pointing
at what looks to already be a function call!).

llvm-svn: 304852
2017-06-07 00:29:44 +00:00
Douglas Gregor 23648d7e3b When constructing source-location information for a
DependentTemplateSpecializationType during tree transformation, retain
the NestedNameSpecifierLoc as it was used to translate the template
name, rather than reconstructing it from the template name.

Fixes PR9401.

llvm-svn: 127015
2011-03-04 18:53:13 +00:00
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