Commit Graph

179 Commits

Author SHA1 Message Date
Richard Smith f57d8cb131 C++11 constant expressions: Don't use CheckICE in C++11; instead, determine
whether an expression is a (core) constant expression as a side-effect of
evaluation. This takes us from accepting far too few expressions as ICEs to
accepting slightly too many -- fixes for the remaining cases are coming next.

The diagnostics produced when an expression is found to be non-constant are
currently quite poor (with generic wording but reasonable source locations),
and will be improved in subsequent commits.

llvm-svn: 146289
2011-12-09 22:58:01 +00:00
Matt Beaumont-Gay 63be19122e Wordsmith the -Warray-bounds diagnostic text a bit
llvm-svn: 145116
2011-11-24 00:27:38 +00:00
Richard Smith 027bf11eb3 Constant expression evaluation: add support for evaluation of member pointers
and base-to-derived casts, and add proper handling of temporaries.

llvm-svn: 144926
2011-11-17 22:56:20 +00:00
Richard Smith ce40ad677e Represent an APValue based on a Decl as that Decl, rather than a DeclRefExpr
or MemberExpr which refers to it. As a side-effect, MemberExprs which refer to
static member functions and static data members are now emitted as constant
expressions.

llvm-svn: 144468
2011-11-12 22:28:03 +00:00
Richard Smith 6804be5a2e Constant expression evalation: const_cast support.
llvm-svn: 144382
2011-11-11 08:28:03 +00:00
Richard Smith e97cbd7b3a Constant expression evaluation: support for constexpr member functions. This
reinstates r144273; a combination of r144333's fix for NoOp rvalue-to-lvalue
casts and some corresponding changes here resolve the regression which that
caused.

This patch also adds support for some additional forms of member function call,
along with additional testing.

llvm-svn: 144369
2011-11-11 04:05:33 +00:00
Devang Patel 63104ad417 Revert r144273. It causes clang self-host build failure.
llvm-svn: 144296
2011-11-10 17:47:39 +00:00
Richard Smith 656d49d890 Constant expression evaluation: support for constexpr member functions.
llvm-svn: 144273
2011-11-10 09:31:24 +00:00
Richard Smith d62306a481 Constant expression evaluation: support for evaluation of structs and unions of
literal types, as well as derived-to-base casts for lvalues and
derived-to-virtual-base casts.

llvm-svn: 144265
2011-11-10 06:34:14 +00:00
Richard Smith f8120cad16 Constant expression evaluation: support for default arguments.
llvm-svn: 144156
2011-11-09 02:12:41 +00:00
Richard Smith ec8dcd2716 Fix a cluster of related issues involving value-dependence and constant
expression evaluation:
 - When folding a non-value-dependent expression, we may try to use the
   initializer of a value-dependent variable. If that happens, give up.
 - In C++98, actually check that a const, non-volatile DeclRefExpr inside an ICE
   is of integral or enumeration type (a reference isn't OK!)
 - In C++11, DeclRefExprs for objects of const literal type initialized with
   value-dependent expressions are themselves value-dependent.
 - So are references initialized with value-dependent expressions (though this
   case is missing from the C++11 standard, along with many others).

llvm-svn: 144056
2011-11-08 01:31:09 +00:00
Richard Smith f3e9e43da4 Constant expression evaluation: support for arrays.
llvm-svn: 143922
2011-11-07 09:22:26 +00:00
Richard Smith 8081560048 Constant expression evaluation: preserve subobject designator when flattening a
core constant value down to an APValue.

llvm-svn: 143909
2011-11-07 05:07:52 +00:00
Richard Smith a08acd8588 Allow constexpr variables' initializers to be folded in C++11 mode. This
partially undoes the revert in r143491, but does not introduce any new instances
of the underlying issue (which is not yet fixed) in code which does not use
the 'constexpr' keyword.

llvm-svn: 143905
2011-11-07 03:22:51 +00:00
Richard Smith fe5354b945 Clean up C++11 constant expression testing.
llvm-svn: 143720
2011-11-04 18:32:57 +00:00
Richard Smith 96e0c101fe Constant expression evaluation: track the manner in which an lvalue was written,
to allow us to implement the C++11 rule that a non-active union member can't be
read, and use it to implement subobject access for string literals.

llvm-svn: 143677
2011-11-04 02:25:55 +00:00
Richard Smith 1a77e8d10d Fix r143463 to test what it was intended to test.
llvm-svn: 143505
2011-11-01 21:48:46 +00:00
Richard Smith 1f1f2d8ca3 Temporarily disable lvalue-to-rvalue conversions on const pointers while an
apparent miscompile triggered by this is investigated. This is essentially a
revert of r143298.

llvm-svn: 143491
2011-11-01 20:38:59 +00:00
Richard Smith fec0992aca Implement C++11 'constexpr calls must return constant expressions' rule, and
perform the code simplifications this rule allows.

llvm-svn: 143463
2011-11-01 16:57:24 +00:00
Eli Friedman c6be94b3de Don't try to fold comparisons between the address of an object and an arbitrary integer constant. Fixes regression from r143334.
llvm-svn: 143374
2011-10-31 22:28:05 +00:00
Eli Friedman 90a2cdf1fb Add missing lvalue-to-rvalue conversion.
llvm-svn: 143364
2011-10-31 20:59:03 +00:00
Richard Smith 4e4c78ffff C++11 generalized constant expression handling: evaluation support for
materialized temporaries.

llvm-svn: 143335
2011-10-31 05:52:43 +00:00
Richard Smith 83c682115b C++11 generalized constant expressions: evaluate equality comparisons between
arbitrary pointers, if those pointers don't point to weak objects or literals.

llvm-svn: 143334
2011-10-31 05:11:32 +00:00
Richard Smith 8b3497ee54 C++11 generalized constant expressions: support pointer comparisons where the
result is not unspecified.

llvm-svn: 143329
2011-10-31 01:37:14 +00:00
Richard Smith 35a1f85466 constexpr evaluation: allow lvalue-to-rvalue conversion on any literal type, not
just integers and floating point types. Since we don't support evaluating class
types or performing lvalue-to-rvalue conversions on array elements yet, this
just means pointer types right now.

llvm-svn: 143298
2011-10-29 21:53:17 +00:00
Richard Smith 0b0a0b6174 constexpr function substitution:
Track the function invocation where an lvalue referring to a constexpr function
parameter originated from, and use it to substitute the correct argument and to
determine whether such an argument's lifetime has ended.

llvm-svn: 143296
2011-10-29 20:57:55 +00:00
Richard Smith 254a73d636 Initial support for C++11 constexpr function invocation substitution. Using
constexpr function arguments outside of their function (passing or returning
them by reference) does not work correctly yet.

Calling constexpr function templates does not work yet, since the bodies are not
instantiated until the end of the translation unit.

llvm-svn: 143234
2011-10-28 22:34:42 +00:00
Richard Smith 11562c5e10 Reinstate r142844 (reverted in r142872) now that lvalue-to-rvalue conversions
are present in all the necessary places:

In constant expression evaluation, evaluate lvalues as lvalues and rvalues as
rvalues. Remove special case for caching reference initialization and fix a
cyclic initialization crash in the process.

llvm-svn: 143204
2011-10-28 17:51:58 +00:00
Richard Smith 08b12f1f5e Fix some cases where a CK_IntegralCast was being used to convert an lvalue to an
rvalue. An assertion to catch this is in ImpCastExprToType will follow, but
vector operations currently trip over this (due to omitting the usual arithmetic
conversions). Also add an assert to catch missing lvalue-to-rvalue conversions
on the LHS of ->.

llvm-svn: 143155
2011-10-27 22:11:44 +00:00