Commit Graph

64 Commits

Author SHA1 Message Date
Richard Smith 6eedfe77c1 Implement C++ DR1391 (wg21.link/cwg1391)
Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside the
immediate context is much more common during substitution than during implicit
conversion sequence formation.

This re-commits r290808, reverted in r290811 and r291412, with a couple of
fixes for handling of explicitly-specified non-trailing template argument
packs.

llvm-svn: 291427
2017-01-09 08:01:21 +00:00
Richard Smith 7950d82ab5 Revert r291410 and r291411.
The test-suite bots are still failing even after r291410's fix.

llvm-svn: 291412
2017-01-09 01:18:18 +00:00
Richard Smith d22652122d Implement C++ DR1391 (wg21.link/cwg1391)
Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside the
immediate context is much more common during substitution than during implicit
conversion sequence formation.

This re-commits r290808, reverted in r290811, with a fix for handling of
explicitly-specified template argument packs.

llvm-svn: 291410
2017-01-09 00:43:47 +00:00
Renato Golin dad96d6751 Revert "DR1391: Check for implicit conversion sequences for non-dependent function template parameters between deduction and substitution. The idea is to accept as many cases as possible, on the basis that substitution failure outside the immediate context is much more common during substitution than during implicit conversion sequence formation."
This reverts commit r290808, as it broken all ARM and AArch64 test-suite
test: MultiSource/UnitTests/C++11/frame_layout

Also, please, next time, try to write a commit message in according to
our guidelines:

http://llvm.org/docs/DeveloperPolicy.html#commit-messages

llvm-svn: 290811
2017-01-02 11:15:42 +00:00
Richard Smith efcfe86072 DR1391: Check for implicit conversion sequences for non-dependent function
template parameters between deduction and substitution. The idea is to accept
as many cases as possible, on the basis that substitution failure outside
the immediate context is much more common during substitution than during
implicit conversion sequence formation.

This does not implement the partial ordering portion of DR1391, which so
far appears to be misguided.

llvm-svn: 290808
2017-01-02 02:42:17 +00:00
George Burgess IV fbad5b2f1b [Sema] Compare bad conversions in overload resolution.
r280553 introduced an issue where we'd emit ambiguity errors for code
like:

```
void foo(int *, int);
void foo(unsigned int *, unsigned int);

void callFoo() {
  unsigned int i;
  foo(&i, 0); // ambiguous: int->unsigned int is worse than int->int,
              // but unsigned int*->unsigned int* is better than
              // int*->int*.
}
```

This patch fixes this issue by changing how we handle ill-formed (but
valid) implicit conversions. Candidates with said conversions now always
rank worse than candidates without them, and two candidates are
considered to be equally bad if they both have these conversions for
the same argument.

Additionally, this fixes a case in C++11 where we'd complain about an
ambiguity in a case like:

```
void f(char *, int);
void f(const char *, unsigned);
void g() { f("abc", 0); }
```

...Since conversion to char* from a string literal is considered
ill-formed in C++11 (and deprecated in C++03), but we accept it as an
extension.

llvm-svn: 280847
2016-09-07 20:03:19 +00:00
David Blaikie ac92893a93 PR5941 - improve diagnostic for * vs & confusion when choosing overload candidate with a parameter of incomplete (ref or pointer) type
Reviewers: dblaikie

Differential Revision: http://reviews.llvm.org/D16949

llvm-svn: 262752
2016-03-04 22:29:11 +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
David Majnemer 475f9eabc2 Update a few more tests in response to the MS ABI enum semantics
Our self hosting buildbots found a few more tests which weren't updated
to reflect that the enum semantics are part of the Microsoft ABI.

llvm-svn: 249670
2015-10-08 08:28:09 +00:00
Richard Smith b94afe1dd6 In C++98, if an rvalue reference binds to a function lvalue (or an xvalue or an
array prvalue), treat that as a direct binding. Only the class prvalue case
needs to be excluded here; the rest are extensions anyway, so we can treat them
as we would in C++11.

llvm-svn: 212978
2014-07-14 19:54:05 +00:00
Richard Smith 19172c4f70 Superficial fix for PR20218: binding a function lvalue to a const reference to
a function pointer is neither better nor worse than binding a function lvalue
to a function rvalue reference. Don't get confused and think that both bindings
are binding to a function lvalue (which would make the lvalue form win); the
const reference is binding to an rvalue.

The "real" bug in PR20218 is still present: we're getting the wrong answer from
template argument deduction, and that's what leads us to this weird overload
set.

llvm-svn: 212916
2014-07-14 02:28:44 +00:00
Nick Lewycky 0c4833f07e Add testcase for r208062.
llvm-svn: 208138
2014-05-06 22:28:58 +00:00
Richard Smith ce4f608f86 DR1152 / PR12931 / PR6177: A candidate function which requires binding a const
volatile reference to a temporary is not viable. My interpretation is that
DR1152 was a bugfix, not a rule change for C++11, so this is not conditional on
the language mode. This matches g++'s behavior.

llvm-svn: 157370
2012-05-24 04:29:20 +00:00
David Blaikie 7555b6a4e5 Improve some of the conversion warnings to fire on conversion to bool.
Moves the bool bail-out down a little in SemaChecking - so now
-Wnull-conversion and -Wliteral-conversion can fire when the target type is
bool.

Also improve the wording/details in the -Wliteral-conversion warning to match
the -Wconstant-conversion.

llvm-svn: 156826
2012-05-15 16:56:36 +00:00
Richard Smith d72da1513a Further improvement to wording of overload resolution diagnostics, and including
the sole parameter name in the diagnostic in more cases. Patch by Terry Long!

llvm-svn: 156807
2012-05-15 06:21:54 +00:00
Richard Smith 10ff50d7d8 PR11857: When the wrong number of arguments are provided for a function
which expects exactly one argument, include the name of the argument in
the diagnostic text. Patch by Terry Long!

llvm-svn: 156607
2012-05-11 05:16:41 +00:00
David Blaikie 09ffc9b473 Enable warn_impcast_literal_float_to_integer by default.
This diagnostic seems to be production ready, it's just an oversight that it
wasn't turned on by default.

The test changes are a bit of a mixed bag. Some tests that seemed like they
clearly didn't need to use this behavior have been modified not to use it.
Others that I couldn't be sure about, I added the necessary expected-warnings
to.

It's possible the diagnostic message could be improved to make it clearer that
this warning can be suppressed by using a value that won't lose precision when
converted to the target type (but can still be a floating point literal, such
as "bool b = 1.0;").

llvm-svn: 154068
2012-04-05 00:16:44 +00:00
Douglas Gregor dfa5b22238 Qualifiers on a canonical array type go on the outermost type, not the
innermost type. Fixes PR12142.

llvm-svn: 152456
2012-03-10 00:29:33 +00:00
Richard Smith e06a2c1893 Fix a regression from r151117: ADL requires that we attempt to complete any
associated classes, since it can find friend functions declared within them,
but overload resolution does not otherwise require argument types to be
complete.

llvm-svn: 151434
2012-02-25 06:24:24 +00:00
Richard Smith fd555f6b1f Implement C++11 [expr.call]p11: If the operand to a decltype-specifier is a
function call (or a comma expression with a function call on its right-hand
side), possibly parenthesized, then the return type is not required to be
complete and a temporary is not bound. Other subexpressions inside a decltype
expression do not get this treatment.

This is implemented by deferring the relevant checks for all calls immediately
within a decltype expression, then, when the expression is fully-parsed,
checking the relevant constraints and stripping off any top-level temporary
binding.

Deferring the completion of the return type exposed a bug in overload
resolution where completion of the argument types was not attempted, which
is also fixed by this change.

llvm-svn: 151117
2012-02-22 02:04:18 +00:00
Richard Trieu 553b2b2e5d Modify how the -verify flag works. Currently, the verification string and
diagnostic message are compared.  If either is a substring of the other, then
no error is given.  This gives rise to an unexpected case:

  // expect-error{{candidate function has different number of parameters}}

will match the following error messages from Clang:

  candidate function has different number of parameters (expected 1 but has 2)
  candidate function has different number of parameters

It will also match these other error messages:

  candidate function
  function has different number of parameters
  number of parameters

This patch will change so that the verification string must be a substring of
the diagnostic message before accepting.  Also, all the failing tests from this
change have been corrected.  Some stats from this cleanup:

87 - removed extra spaces around verification strings
70 - wording updates to diagnostics
40 - extra leading or trailing characters (typos, unmatched parens or quotes)
35 - diagnostic level was included (error:, warning:, or note:)
18 - flag name put in the warning (-Wprotocol)

llvm-svn: 146619
2011-12-15 00:38:15 +00:00
Douglas Gregor cda2270217 Allow calling an overloaded function set by taking the address of the
functions, e.g., (&f)(0). Fixes <rdar://problem/9803316>.

llvm-svn: 141877
2011-10-13 18:10:35 +00:00
Douglas Gregor 377c109f21 Identity and non-identity standard conversion sequences can be
compared even when one is a reference binding and the other is not
(<rdar://problem/9173984>), but the definition of an identity sequence
does not involve lvalue-to-rvalue adjustments (PR9507). Fix both
inter-related issues.

llvm-svn: 132660
2011-06-05 06:15:20 +00:00
Douglas Gregor 928479e727 Revert the fix for PR8013.
That bug concerned the well-formedness of code such as (&ovl)(a, b,
c). GCC rejects the code, while EDG accepts it. On further study of the
standard, I see no support for EDG's position: in particular, C++
[over.over] does not list this as a context where we can take the
address of an overloaded function, C++ [over.call.func] does not
reference the address-of operator at any point, and C++ [expr.call]
claims that the function argument in a call is either a function
lvalue or a pointer-to-function; (&ovl) is neither.

llvm-svn: 118620
2010-11-09 20:03:54 +00:00
Douglas Gregor 8f225bb508 Handle overload resolution when calling an overloaded function set
with, e.g., (&f)(a, b, c). Fixes PR8013.

llvm-svn: 118508
2010-11-09 16:13:15 +00:00
Argyrios Kyrtzidis a992bbc08a Add test case for r115588.
llvm-svn: 115590
2010-10-05 03:15:43 +00:00
Chris Lattner 53fa04909c make clang print types as "const int *" instead of "int const*",
which is should have done from the beginning.  As usual, the most
fun with this sort of change is updating all the testcases.

llvm-svn: 113090
2010-09-05 00:04:01 +00:00
Douglas Gregor fb0c0d37b7 Extend the "cannot convert from base class pointer to derived class
pointer" diagnostic to handle references, too.

llvm-svn: 107372
2010-07-01 02:14:45 +00:00
Douglas Gregor 56f2e34a6a Improve diagnostic when we fail to pick an overload because it would
require a base-to-derived pointer conversion.

llvm-svn: 107349
2010-06-30 23:01:39 +00:00
Douglas Gregor 689999da1f String literals enclosed in parentheses are still string
literals. Fixes PR7488.

llvm-svn: 106607
2010-06-22 23:47:37 +00:00
Douglas Gregor 1fc3d66da4 Tweak our handling of the notion of a standard conversion sequence
being a subsequence of another standard conversion sequence. Instead
of requiring exact type equality for the second conversion step,
require type *similarity*, which is type equality with cv-qualifiers
removed at all levels. This appears to match the behavior of EDG and
VC++ (albeit not GCC), and feels more intuitive. Big thanks to John
for the line of reasoning that supports this change: since
cv-qualifiers are orthogonal to the second conversion step, we should
ignore them in the type comparison.

llvm-svn: 105678
2010-06-09 03:53:18 +00:00
Douglas Gregor b9f907bafc Make sure to strip off top-level cv-qualifiers as part of a
derived-to-base conversion on a pointer. Fixes PR7224.

llvm-svn: 104607
2010-05-25 15:31:05 +00:00
Douglas Gregor e87561aa2e An identity conversion is better than any non-identity
conversion. Fixes PR7095.

llvm-svn: 104476
2010-05-23 22:10:15 +00:00
Douglas Gregor c779e99540 When we are performing copy initialization of a class type via its
copy constructor, suppress user-defined conversions on the
argument. Otherwise, we can end up in a recursion loop where the
bind the argument of the copy constructor to another copy constructor call,
whose argument is then a copy constructor call...

Found by Boost.Regex which, alas, still isn't building.

llvm-svn: 102269
2010-04-24 20:54:38 +00:00
Douglas Gregor 4f4946aaaa Whenever we complain about a failed initialization of a function or
method parameter, provide a note pointing at the parameter itself so
the user does not have to manually look for the function/method being
called and match up parameters to arguments. For example, we now get:

t.c:4:5: warning: incompatible pointer types passing 'long *' to
parameter of
      type 'int *' [-pedantic]
  f(long_ptr);
    ^~~~~~~~
t.c:1:13: note: passing argument to parameter 'x' here
void f(int *x);
            ^

llvm-svn: 102038
2010-04-22 00:20:18 +00:00
Douglas Gregor 870f3743e4 When performing reference initialization for the purposes of overload
resolution ([over.ics.ref]), we take some shortcuts required by the
standard that effectively permit binding of a const volatile reference
to an rvalue. We have to treat lightly here to avoid infinite
recursion.

Fixes PR6177.

llvm-svn: 101712
2010-04-18 09:22:00 +00:00
Douglas Gregor e5e775bc8e When returning the result of a call to an object of class type, do not
return a NULL expression; return either an error or a proper
expression. Fixes PR6078.

llvm-svn: 101133
2010-04-13 15:50:39 +00:00
Douglas Gregor 1ce52caf0d Reference binding via user-defined conversion can compute a binding
that is not reference-related (because it requires another implicit
conversion to which we can find). Fixes PR6483.

llvm-svn: 97922
2010-03-07 23:17:44 +00:00
Douglas Gregor e489a7d3d3 Warn about the deprecated string literal -> char* conversion. Fixes PR6428.
llvm-svn: 97404
2010-02-28 18:30:25 +00:00
Douglas Gregor 83af86a6bc Allow us to compare derived-to-base conversions between a reference
binding and a copy-construction. Fixes an overloading problem in the
Clang-on-Clang build.

llvm-svn: 97161
2010-02-25 19:01:05 +00:00
John McCall 21b57fa4e5 When comparing two method overload candidates during overload diagnostics,
skip the object argument conversion if either of the candidates didn't
initialize it.

Fixes PR6421, which is such a very straightforward extension of PR6398 that I
should have worked it into the last test case (and therefore caught it then).
Ah well.

llvm-svn: 97135
2010-02-25 10:46:05 +00:00
John McCall 65eb879d22 Catch more uses of uninitialized implicit conversion sequences.
When diagnosing bad conversions, skip the conversion for ignored object
arguments.  Fixes PR 6398.

llvm-svn: 97090
2010-02-25 01:37:24 +00:00
Douglas Gregor 3edc4d5ec3 Fix a major oversight in the comparison of standard conversion
sequences, where we would occasionally determine (incorrectly) that
one standard conversion sequence was a proper subset of another when,
in fact, they contained completely incomparable conversions. 

This change records the types in each step within a standard
conversion sequence, so that we can check the specific comparison
types to determine when one sequence is a proper subset of the
other. Fixes this testcase (thanks, Anders!), which was distilled from
PR6095 (also thanks to Anders).

llvm-svn: 94660
2010-01-27 03:51:04 +00:00
John McCall 6d174646dd Produce a special diagnostic when users call a function with an argument of
incomplete type (or a pointer/reference to such).

The causes of this problem are different enough to justify a different "design"
for the diagnostic.  Most notably, it doesn't give an operand index:
it's usually pretty obvious which operand is the problem, it adds a lot of
clutter to mention it, and the fix is usually in a different part of the file
anyway.

This is yet another diagnostic that should really have an analogue in the
non-overloaded case --- which should be much easier to write because of
the weaker space constraints.

llvm-svn: 94303
2010-01-23 08:10:49 +00:00
John McCall a1709fd822 Improve the diagnostic for bad conversions in overload resolution to talk
about 'object argument' vs. 'nth argument'.

llvm-svn: 93395
2010-01-14 00:56:20 +00:00
John McCall e8c8cd2a58 Don't report ambiguities in the user-defined conversion if we weren't supposed
to be considering user-defined conversions in the first place.

Doug, please review;  I'm not sure what we should be doing if we see a real
ambiguity in selecting a copy constructor when otherwise suppressing
user-defined conversions.

Fixes PR6014.

llvm-svn: 93365
2010-01-13 22:30:33 +00:00
John McCall 6a61b5203d Record some basic information about bad conversion sequences. Use that
information to feed diagnostics instead of regenerating it.  Much room for
improvement here, but fixes some unfortunate problems reporting on method calls.

llvm-svn: 93316
2010-01-13 09:16:55 +00:00
John McCall e1ac8d1742 Improve the reporting of non-viable overload candidates by noting the reason
why the candidate is non-viable.  There's a lot we can do to improve this, but
it's a good start.  Further improvements should probably be integrated with the
bad-initialization reporting routines.

llvm-svn: 93277
2010-01-13 00:25:19 +00:00
John McCall 53262c96d9 Reorganize some of the code to note overload candidates. Improves the
fidelity with which we note them as functions/constructors and templates
thereof.  Also will be helpful when reporting bad conversions (next).

llvm-svn: 93224
2010-01-12 02:15:36 +00:00
Daniel Dunbar 8fbe78f6fc Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
   which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
   can be useful to redefine what gets run as 'clang -cc1' (for example, to set
   a default target).

llvm-svn: 91446
2009-12-15 20:14:24 +00:00