Commit Graph

15 Commits

Author SHA1 Message Date
Matheus Izvekov ad14b5b008 [clang] Stop providing builtin overload candidate for relational function pointer comparisons
Word on the grapevine was that the committee had some discussion that
ended with unanimous agreement on eliminating relational function pointer comparisons.

We wanted to be bold and just ban all of them cold turkey.
But then we chickened out at the last second and are going for
eliminating just the spaceship overload candidate instead, for now.

See D104680 for reference.

This should be fine and "safe", because the only possible semantic change this
would cause is that overload resolution could possibly be ambiguous if
there was another viable candidate equally as good.

But to save face a little we are going to:
* Issue an "error" for three-way comparisons on function pointers.
  But all this is doing really is changing one vague error message,
  from an "invalid operands to binary expression" into an
  "ordered comparison of function pointers", which sounds more like we mean business.
* Otherwise "warn" that comparing function pointers like that is totally
  not cool (unless we are told to keep quiet about this).

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D104892
2021-06-26 00:08:02 +02:00
Richard Smith 0c42539df3 Improve error recovery from missing '>' in template argument list.
Produce the conventional "to match this '<'" note, so that the user
knows why we expected a '>', and properly handle '>>' in C++11 onwards.
2020-03-27 18:59:01 -07:00
Richard Smith beda951d78 Make tentative parsing to detect template-argument-lists less aggressive
(and less wrong).

It's not correct to assume that X<something, Type> is always a
template-id; there are a few cases where the comma takes us into a
non-expression syntactic context in which 'Type' might be permissible.
Stop doing that.

This slightly regresses our error recovery on the cases where the
construct is intended to be a template-id. We typically do still manage
to diagnose a missing 'template' keyword, but we realize this too late
to properly recover from the error.

This fixes a regression introduced by r360308.

llvm-svn: 360827
2019-05-15 23:36:14 +00:00
Richard Smith b23c5e8c3d [c++20] Implement P0846R0: allow (ADL-only) calls to template-ids whose
template name is not visible to unqualified lookup.

In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.

Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.

The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.

llvm-svn: 360308
2019-05-09 03:31:27 +00:00
Richard Smith 74639b1900 When a type-id is unexpectedly given a name, assume that the name is unrelated
syntax unless we have a reason to think otherwise.

This improves error recovery in a couple of cases.

llvm-svn: 303398
2017-05-19 01:54:59 +00:00
Charles Li 85dec55989 [Lit Test] Updated 20 Lit tests to be C++11 compatible.
This is the 5th Lit test patch.
Expanded expected diagnostics to vary by C++ dialect.
Expanded RUN line to: default, C++98/03 and C++11.

llvm-svn: 255196
2015-12-10 01:07:17 +00:00
Richard Smith bdf54a21b5 PR18793: If we try to EnterTokenStream when our current lexer is a caching
lexer, add the token buffer underneath the caching lexer where possible and
push the tokens directly into the caching lexer otherwise. We previously
put the lexer into a corrupted state where we could not guarantee to provide
the tokens in the right order and would sometimes assert.

llvm-svn: 218333
2014-09-23 21:05:52 +00:00
Faisal Vali cb7e5df97e Fix PR17637: incorrect calculation of template parameter depth
In delayed template parsing mode, adjust the template depth counter for each template parameter list associated with an out of line member template specialization.

llvm-svn: 196351
2013-12-04 03:51:14 +00:00
Serge Pavlov b716b3ca1f Avoid spurious error messages if parent template class cannot be instantiated
Differential Revision: http://llvm-reviews.chandlerc.com/D924

llvm-svn: 188133
2013-08-10 05:54:47 +00:00
Richard Smith 9ce302ed9c PR5066: If a declarator cannot have an identifier, and cannot possibly be
followed by an identifier, then diagnose an identifier as being a bogus part of
the declarator instead of tripping over it. Improves diagnostics for cases like

  std::vector<const int *p> my_vec;

llvm-svn: 186061
2013-07-11 05:10:21 +00:00
Richard Smith 4f605aff7f PR41111, PR5925, PR13210: Teach tentative parsing to annotate identifiers and
nested names as id-expressions, using the annot_primary_expr annotation, where
possible. This removes some redundant lookups, and also allows us to
typo-correct within tentative parsing, and to carry on disambiguating past an
identifier which we can determine will fail lookup as both a type and as a
non-type, allowing us to disambiguate more declarations (and thus offer
improved error recovery for such cases).

This also introduces to the parser the notion of a tentatively-declared name,
which is an identifier which we *might* have seen a declaration for in a
tentative parse (but only if we end up disambiguating the tokens as a
declaration). This is necessary to correctly disambiguate cases where a
variable is used within its own initializer.

llvm-svn: 162159
2012-08-18 00:55:03 +00:00
Richard Smith 7b3f322517 Extend the error recovery for a template-argument-list terminated by '>>' to
also deal with '>>>' (in CUDA), '>=', and '>>='. Fix the FixItHints logic to
deal with cases where the token is followed by an adjacent '=', '==', '>=',
'>>=', or '>>>' token, where a naive fix-it would result in a differing token
stream on a re-lex.

llvm-svn: 158652
2012-06-18 06:11:04 +00:00
Douglas Gregor 94a32477fd When we're inside a functional cast, '>' is an operator. Fixes PR8912.
llvm-svn: 123201
2011-01-11 00:33:19 +00:00
John McCall 1f476a1783 Fix an assertion-on-error during tentative constructor parsing by
propagating error conditions out of the various annotate-me-a-snowflake
routines.  Generally (but not universally) removes redundant diagnostics
as well as, you know, not crashing on bad code.  On the other hand,
I have just signed myself up to fix fiddly parser errors for the next
week.  Again.

llvm-svn: 97221
2010-02-26 08:45:28 +00:00
Eli Friedman affd5fdf37 Make sure to give an error for template argument lists followed by junk.
llvm-svn: 92177
2009-12-27 22:31:18 +00:00