Commit Graph

5 Commits

Author SHA1 Message Date
Richard Smith e5945871cf Revisit PR10177: don't instantiate a variable if it's only referenced in a
dependent context and can't be used in a constant expression.

Per C++ [temp.inst]p2, "the instantiation of a static data member does not
occur unless the static data member is used in a way that requires the
definition to exist".

This doesn't /quite/ match that, as we still instantiate static data members
that are usable in constant expressions even if the use doesn't require a
definition. A followup patch will fix that for both variables and functions.

llvm-svn: 291295
2017-01-06 22:52:53 +00:00
Serge Pavlov 7dcc97e7ac Warn if function or variable cannot be implicitly instantiated
With this patch compiler emits warning if it tries to make implicit instantiation
of a template but cannot find the template definition. The warning can be suppressed
by explicit instantiation declaration or by command line options
-Wundefined-var-template and -Wundefined-func-template. The implementation follows
the discussion of http://reviews.llvm.org/D12326.

Differential Revision: http://reviews.llvm.org/D16396

llvm-svn: 266719
2016-04-19 06:19:52 +00:00
Larisse Voufo f73da98f48 Not all instantiated variable is odr-used. Do not mark non-odr-used variable template specializations as such.
llvm-svn: 214267
2014-07-30 00:49:55 +00:00
Larisse Voufo b6fab26109 Fix PR10177 where non-type template arguments to alias templates are not marked as used in dependent contexts. The fix actually forces non-dependent names to be checked at template definition time as expected from the standard.
llvm-svn: 214192
2014-07-29 18:44:19 +00:00
Richard Smith 764d2fe666 Unlike in C++03, a constant-expression is not an unevaluated operand in C++11.
Split out a new ExpressionEvaluationContext flag for this case, and don't treat
it as unevaluated in C++11. This fixes some crash-on-invalids where we would
allow references to class members in potentially-evaluated constant expressions
in static member functions, and also fixes half of PR10177.

The fix to PR10177 exposed a case where template instantiation failed to provide
a source location for a diagnostic, so TreeTransform has been tweaked to supply
source locations when transforming a type. The source location is still not very
good, but MarkDeclarationsReferencedInType would need to operate on a TypeLoc to
improve it further.

Also fix MarkDeclarationReferenced in C++98 mode to trigger instantiation for
static data members of class templates which are used in constant expressions.
This fixes a link-time problem, but we still incorrectly treat the member as
non-constant. The rest of the fix for that issue is blocked on PCH support for
early-instantiated static data members, which will be added in a subsequent
patch.

llvm-svn: 146955
2011-12-20 02:08:33 +00:00