Commit Graph

22 Commits

Author SHA1 Message Date
Richard Smith 08d6a2cc7a C++1y: track object lifetime during constexpr evaluation, and don't allow
objects to be used once their lifetimes end. This completes the C++1y
constexpr extensions.

llvm-svn: 187025
2013-07-24 07:11:57 +00:00
Richard Smith 3da88fac54 C++1y: support simple variable assignments in constexpr functions.
llvm-svn: 180603
2013-04-26 14:36:30 +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 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 e434590bd9 Change the diagnostics which said 'accepted as an extension' to instead say
'is an extension'. The former is inappropriate and confusing when building with
-Werror/-pedantic-errors.

llvm-svn: 147357
2011-12-29 21:57:33 +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
Richard Smith 733237db23 Revert r142844, it broke selfhost. The problem appears to be a missing
lvalue-to-rvalue conversion on the LHS operand of '->'.

llvm-svn: 142872
2011-10-24 23:14:33 +00:00
Richard Smith cbb407268e Constant expression evaluation: evaluate lvalues as lvalues, and rvalues as
rvalues, as C++11 constant evaluation semantics require. DeclRefs referring to
references can now use the normal initialization-caching codepath, which
incidentally fixes a crash in cyclic initialization of references.

llvm-svn: 142844
2011-10-24 21:07:08 +00:00
Richard Smith c3e31e7bb2 In accordance with the C89, C99 and C++98 standards, ICEs can only contain
floating-point literals if they are the immediate operands of casts.
ImplicitCastExpr is not a cast in the language-standards sense.

llvm-svn: 142832
2011-10-24 18:26:35 +00:00
Eli Friedman ce3e02a343 Extend lvalue evaluation in ExprConstant.cpp to handle CK_LValueBitCast (which is completely trivial). PR8836.
llvm-svn: 141604
2011-10-11 00:13:24 +00:00
Eli Friedman 76d4e43063 PR11040: CheckICE should not allow an lvalue bitcast as part of an integer constant expression.
llvm-svn: 140812
2011-09-29 21:49:34 +00:00
Chris Lattner 9925ec8bf4 fix rdar://9204520 - Accept int(0.85 * 10) as an initializer in a class member
as an extension.

llvm-svn: 132980
2011-06-14 05:46:29 +00:00
Eli Friedman abebebf742 Update test for r113128.
llvm-svn: 113131
2010-09-06 00:30:50 +00:00
John McCall d3dfbd6f4f If a switch condition is constant, don't warn about missing enum cases.
If a switch condition is constant, warn if there's no case for it.

Constant switch conditions do come up in reasonable template code.

llvm-svn: 104010
2010-05-18 03:19:21 +00:00
John McCall 6dee473780 References to const int parameters with ICE default arguments are not ICEs.
Fixes PR6373.

llvm-svn: 97037
2010-02-24 09:03:18 +00:00
John McCall 52cc0897f3 Per discussion, remove the explicit restriction on static const data members with
out-of-line initializers as integer constant expressions.  Fixes PR6206.

llvm-svn: 95463
2010-02-06 01:07:37 +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
Eli Friedman 1d6fb1669c Add recursion guards to ice-checking and evaluation for declrefs, so we
don't infinitely recurse for cases we can't evaluate.

llvm-svn: 90480
2009-12-03 20:31:57 +00:00
Douglas Gregor 8ef65fbd49 Eliminate some "default"s in CheckICE.
llvm-svn: 81477
2009-09-10 23:31:45 +00:00
Douglas Gregor 7736e2ad98 static_cast, reinterpret_cast, and const_cast can all be used in C++
integral constant expressions (for conversions to integer types,
naturally). I don't *think* that const_casts will ever get to this
point, but I also can't convince myself that they won't... so I've
taken the safe route and allowed the ICE checking code to look at
const_cast.

llvm-svn: 81453
2009-09-10 17:44:23 +00:00
Daniel Dunbar a45cf5b6b0 Rename clang to clang-cc.
Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
2009-03-24 02:24:46 +00:00
Sebastian Redl f3b5e27fee Make const-initialized const integral variables I-C-Es in C++.
llvm-svn: 64015
2009-02-07 13:06:23 +00:00