Commit Graph

56 Commits

Author SHA1 Message Date
Richard Smith 410cc89374 [c++1z] Most of N4268 (allow constant evaluation for non-type template arguments).
We don't yet support pointer-to-member template arguments that have undergone
pointer-to-member conversions, mostly because we don't have a mangling for them yet.

llvm-svn: 222807
2014-11-26 03:26:53 +00:00
Richard Smith 640775b428 PR21180: Lambda closure types are neither aggregates nor literal types.
llvm-svn: 219222
2014-10-07 18:01:33 +00:00
Richard Smith 6c6bbfab19 PR19346: Adding 0 to a null pointer has defined behavior in C++. Allow it in constant expressions.
llvm-svn: 205757
2014-04-08 12:19:28 +00:00
Yunzhong Gao fcdc45ff2d Creating a printing policy for "half":
Since "half" is an OpenCL keyword and clang accepts __fp16 as an extension for
other languages, error messages and metadata (and hence debug info) should refer
to the half-precision floating point as "__fp16" instead of "half" when
compiling for non-OpenCL languages. This patch creates a new printing policy for
half in a similar manner to what is done for bool and wchar_t.

Differential Revision: http://llvm-reviews.chandlerc.com/D2952

llvm-svn: 204164
2014-03-18 17:55:18 +00:00
Alp Toker 6ed7251683 Revert "Don't require -re suffix on -verify directives with regexes."
This patch was submitted to the list for review and didn't receive a LGTM.

(In fact one explicit objection and one query were raised.)

This reverts commit r197295.

llvm-svn: 197299
2013-12-14 01:07:05 +00:00
Hans Wennborg 9b395ef284 Don't require -re suffix on -verify directives with regexes.
Differential Revision: http://llvm-reviews.chandlerc.com/D2392

llvm-svn: 197295
2013-12-14 00:46:53 +00:00
Hans Wennborg 86be54cc80 Tighten test regexes checking for __attribute__((thiscall)) on function types.
The tests were perhaps made too relaxed in r197164 when we switched to the new
MinGW ABI. This makes sure we check explicitly for an optional thiscall
attribute and nothing else.

We should still look into whether we should print these attributes at all in
these cases.

llvm-svn: 197252
2013-12-13 18:34:23 +00:00
Rafael Espindola 3497069784 Switch to the new MingW ABI.
GCC 4.7 changed the MingW ABI. On the clang side this means that methods now
have the thiscall calling convention by default.

llvm-svn: 197164
2013-12-12 16:07:11 +00:00
David Majnemer 9adc361008 Sema: Do not allow lambda expressions to appear inside of constant expressions
We would previously not diagnose this which would lead to crashes (on
very strange code).

This fixes PR17675.

llvm-svn: 193397
2013-10-25 09:12:52 +00:00
Larisse Voufo 98b20f1278 FIXME fix: improving diagnostics for template arguments deduction of class templates and explicit specializations
This patch essentially removes all the FIXMEs following calls to DeduceTemplateArguments() that want to keep track of deduction failure info.

llvm-svn: 186730
2013-07-19 23:00:19 +00:00
Larisse Voufo 47c0845e0b Revert "Use function overloading instead of template specialization for diagnosis of bad template argument deductions."
This reverts commit a730f548325756d050d4caaa28fcbffdae8dfe95.

llvm-svn: 186729
2013-07-19 22:53:23 +00:00
Larisse Voufo 8d33da6d58 Use function overloading instead of template specialization for diagnosis of bad template argument deductions.
llvm-svn: 186727
2013-07-19 22:34:32 +00:00
Richard Smith 82c9b5183f Fix handling of const_cast from prvalue to rvalue reference: such a cast is
only permitted if the source object is of class type, and should materialize a
temporary for the reference to bind to.

llvm-svn: 184017
2013-06-14 22:27:52 +00:00
Richard Smith 844010455d Refactor constant expression evaluation to associate the complete object of a
materialized temporary with the corresponding MaterializeTemporaryExpr. This is
groundwork for providing C++11's guaranteed static initialization for global
references bound to lifetime-extended temporaries (if the initialization is a
constant expression).

In passing, fix a couple of bugs where some evaluation failures didn't trigger
diagnostics, and a rejects-valid where potential constant expression testing
would assume that it knew the dynamic type of *this and would reject programs
which relied on it being some derived type.

llvm-svn: 183093
2013-06-03 05:03:02 +00:00
Richard Smith 034185c2f9 The 'constexpr implies const' rule for non-static member functions is gone in
C++1y, so stop adding the 'const' there. Provide a compatibility warning for
code relying on this in C++11, with a fix-it hint. Update our lazily-written
tests to add the const, except for those ones which were testing our
implementation of this rule.

llvm-svn: 179969
2013-04-21 01:08:50 +00:00
Douglas Gregor 0b7bc7f996 Don't crash while printing APValues that are lvalues casted to a
decidedly non-reference, non-pointer type. Fixes <rdar://problem/13090123>.

llvm-svn: 173747
2013-01-29 01:26:43 +00:00
Michael Han 64536a6d25 Teach Clang parser to reject C++11 attributes that appertain to declaration specifiers.
We don't support any C++11 attributes that appertain to declaration specifiers so reject 
the attributes in parser until we support them; this also conforms to what g++ 4.8 is doing.

llvm-svn: 167481
2012-11-06 19:34:54 +00:00
Andy Gibbs c6e68daac0 Prior to adding the new "expected-no-diagnostics" directive to VerifyDiagnosticConsumer, make the necessary adjustment to 580 test-cases which will henceforth require this new directive.
llvm-svn: 166280
2012-10-19 12:44:48 +00:00
Richard Smith ca24ed473b Revert r163829. The world (or libstdc++, at least) is not ready.
llvm-svn: 163846
2012-09-13 22:00:12 +00:00
Richard Smith b67ada6687 Remove speculative fix for C++ core issue 1407, since it was resolved as NAD.
llvm-svn: 163829
2012-09-13 19:55:13 +00:00
Eli Friedman 4eafb6b77b Don't treat overflow in floating-point conversions as a hard error in constant evaluation. <rdar://problem/11874571>.
llvm-svn: 160394
2012-07-17 21:03:05 +00:00
Eli Friedman 2b22a6e61c Extend -Wc++11-narrowing to cover converted constant expressions as well as braced-initializers. <rdar://problem/11121178>.
llvm-svn: 153703
2012-03-29 23:39:39 +00:00
Richard Smith 35ecb36fcd Ensure that we instantiate static reference data members of class templates
early, since their values can be used in constant expressions in C++11. For
odr-use checking, the opposite change is required, since references are
odr-used whether or not they satisfy the requirements for appearing in a
constant expression.

llvm-svn: 151881
2012-03-02 04:14:40 +00:00
Richard Smith b228a86fcf Implement DR1454. This allows all intermediate results in constant expressions
to be core constant expressions (including pointers and references to
temporaries), and makes constexpr calculations Turing-complete. A Turing machine
simulator is included as a testcase.

This opens up the possibilty of removing CCValue entirely, and removing some
copies from the constant evaluator in the process, but that cleanup is not part
of this change.

llvm-svn: 150557
2012-02-15 02:18:13 +00:00
Richard Smith 3607ffee5c Update constexpr implementation to match CWG's chosen approach for core issues
1358, 1360, 1452 and 1453.
 - Instantiations of constexpr functions are always constexpr. This removes the
   need for separate declaration/definition checking, which is now gone.
 - This makes it possible for a constexpr function to be virtual, if they are
   only dependently virtual. Virtual calls to such functions are not constant
   expressions.
 - Likewise, it's now possible for a literal type to have virtual base classes.
   A constexpr constructor for such a type cannot actually produce a constant
   expression, though, so add a special-case diagnostic for a constructor call
   to such a type rather than trying to evaluate it.
 - Classes with trivial default constructors (for which value initialization can
   produce a fully-initialized value) are considered literal types.
 - Classes with volatile members are not literal types.
 - constexpr constructors can be members of non-literal types. We do not yet use
   static initialization for global objects constructed in this way.

llvm-svn: 150359
2012-02-13 03:54:03 +00:00
Richard Smith 0cd4ab194b Update to new resolution for DR1458. When taking the address of an object of
incomplete class type which has an overloaded operator&, it's now just
unspecified whether the overloaded operator or the builtin is used.

llvm-svn: 150234
2012-02-10 07:41:06 +00:00
Richard Smith 90cacbbf3e Implement DR1458: Taking the address of an object of incomplete class type is
not a constant expression, because we can't tell whether the complete class type
will have an overloaded operator&.

llvm-svn: 150066
2012-02-08 08:11:33 +00:00
Richard Smith 3c7ad4e01b Add more testing for r149776.
llvm-svn: 150061
2012-02-08 06:41:34 +00:00
Richard Smith da7c4ba1af Implement the agreed resolution to DR1457: a signed left shift of a 1 bit into
the sign bit doesn't have undefined behavior, but a signed left shift of a 1 bit
out of the sign bit still does. As promised to Howard :)

The suppression of the potential constant expression checking in system headers
is also removed, since the problem it was working around is gone.

llvm-svn: 150059
2012-02-08 06:14:53 +00:00
Richard Smith c82fae6070 constexpr: Fix implementation of DR1311: check for volatile qualifiers in
lvalue-to-rvalue conversions on the source type of the conversion, not the
target type (which has them removed for non-class types).

llvm-svn: 149796
2012-02-05 01:23:16 +00:00
Richard Smith f4c51d9d76 In C++11 mode, when an integral constant expression is desired and we have a
value of class type, look for a unique conversion operator converting to
integral or unscoped enumeration type and use that. Implements [expr.const]p5.

Sema::VerifyIntegerConstantExpression now performs the conversion and returns
the converted result. Some important callers of Expr::isIntegralConstantExpr
have been switched over to using it (including all of those required for C++11
conformance); this switch brings a side-benefit of improved diagnostics and, in
several cases, simpler code. However, some language extensions and attributes
have not been moved across and will not perform implicit conversions on
constant expressions of literal class type where an ICE is required.

In passing, fix static_assert to perform a contextual conversion to bool on its
argument.

llvm-svn: 149776
2012-02-04 09:53:13 +00:00
Richard Smith 84f6dcf2b5 constexpr:
* support the gcc __builtin_constant_p() ? ... : ... folding hack in C++11
  * check for unspecified values in pointer comparisons and pointer subtractions

llvm-svn: 149578
2012-02-02 01:16:57 +00:00
Richard Smith 1b470417e4 constexpr: check for overflow in pointer subtraction.
This is a mess. According to the C++11 standard, pointer subtraction only has
undefined behavior if the difference of the array indices does not fit into a
ptrdiff_t.

However, common implementations effectively perform a char* subtraction first,
and then divide the result by the element size, which can cause overflows in
some cases. Those cases are not considered to be undefined behavior by this
change; perhaps they should be.

llvm-svn: 149490
2012-02-01 08:10:20 +00:00
Richard Smith c8042323e1 constexpr: overflow checking for integral and floating-point arithmetic.
llvm-svn: 149473
2012-02-01 05:53:12 +00:00
Richard Smith 47b349328b constexpr: require 'this' to point to an object in a constexpr method call.
llvm-svn: 149467
2012-02-01 02:39:43 +00:00
Richard Smith 000e9aa7ed constexpr: Treat INT_MIN % -1 as undefined behavior in C++11. Technically, it
isn't, but this is just a (reported) defect in the wording.

llvm-svn: 149448
2012-01-31 23:24:19 +00:00
Richard Smith de21b245c6 constexpr: the result of a relational operator between pointers to void is
unspecified unless the pointers are equal; therefore, such a comparison is not
a constant expression unless the pointers are equal.

llvm-svn: 149366
2012-01-31 06:41:30 +00:00
Richard Smith fe800031ec constexpr: catch a collection of integral undefined behaviors:
-INT_MIN and INT_MIN / -1
  Shift by a negative or too large quantity
  Left shift of negative value
  Overflow in left shift

llvm-svn: 149344
2012-01-31 04:08:20 +00:00
Richard Smith 006bfc91e8 constexpr: remove integral conversion overflow checking introduced in r149286.
As Eli points out, this is implementation-defined, and the way we define it
makes this fine.

llvm-svn: 149327
2012-01-31 01:47:46 +00:00
Richard Smith 911e142f03 constexpr: disallow signed integer overflow in integral conversions in constant
expressions in C++11.

llvm-svn: 149286
2012-01-30 22:27:01 +00:00
Richard Smith f8379a0fc3 constexpr: converted constant expression handling for enumerator values, case
values and non-type template arguments of integral and enumeration types.

This change causes some legal C++98 code to no longer compile in C++11 mode, by
enforcing the C++11 rule that narrowing integral conversions are not permitted
in the final implicit conversion sequence for the above cases.

llvm-svn: 148439
2012-01-18 23:55:52 +00:00
Richard Smith 2ec4061e39 Pedantic diagnostic correction: in C++, we have integral constant expressions,
not integer constant expressions. In passing, fix the 'folding is an extension'
diagnostic to not claim we're accepting the code, since that's not true in
-pedantic-errors mode, and add this diagnostic to -Wgnu.

llvm-svn: 148209
2012-01-15 03:51:30 +00:00
Richard Smith 02ab9c2940 Allow constant-folding of references which were formed in a manner not permitted
in a constant expression, for compatibility with g++.

llvm-svn: 148020
2012-01-12 06:08:57 +00:00
Richard Smith a8105bc9ce C++11 generalized constant expressions: implement checking and diagnostics for
pointer-arithmetic-related undefined behavior and unspecified results. We
continue to fold such values, but now notice they aren't constant expressions.

llvm-svn: 147659
2012-01-06 16:39:00 +00:00
Richard Smith fddd384b73 Unrevert r147271, reverted in r147361.
Also temporarily remove the assumption from IR gen that we can emit IR for every
constant we can fold, since it isn't currently true in C++11, to fix PR11676.

Original comment from r147271:

constexpr: perform zero-initialization prior to / instead of performing a
constructor call when appropriate. Thanks to Eli for spotting this.

llvm-svn: 147384
2011-12-30 21:15:51 +00:00
Rafael Espindola fafe4b7572 Revert r147271. This fixes PR11676.
llvm-svn: 147362
2011-12-30 03:11:50 +00:00
Richard Smith 6e52514c5d constexpr: support for evaluation and codegen of typeid constants.
llvm-svn: 147290
2011-12-27 12:18:28 +00:00
Richard Smith 771c4a1775 constexpr: perform zero-initialization prior to / instead of performing a
constructor call when appropriate. Thanks to Eli for spotting this.

llvm-svn: 147271
2011-12-25 20:00:17 +00:00
Richard Smith f2b681b4d8 constexpr: diagnostic improvements for invalid lvalue-to-rvalue conversions in
constant expressions.

llvm-svn: 147035
2011-12-21 05:04:46 +00:00
Richard Smith d0b4dd656d constexpr handling improvements. Produce detailed diagnostics when a 'constexpr'
variable is initialized by a non-constant expression, and pass in the variable
being declared so that earlier-initialized fields' values can be used.

Rearrange VarDecl init evaluation to make this possible, and in so doing fix a
long-standing issue in our C++ constant expression handling, where we would
mishandle cases like:

  extern const int a;
  const int n = a;
  const int a = 5;
  int arr[n];

Here, n is not initialized by a constant expression, so can't be used in an ICE,
even though the initialization expression would be an ICE if it appeared later
in the TU. This requires computing whether the initializer is an ICE eagerly,
and saving that information in PCH files.

llvm-svn: 146856
2011-12-19 06:19:21 +00:00