Commit Graph

876 Commits

Author SHA1 Message Date
Richard Smith 8921007090 Move local helper class into anonymous namespace.
llvm-svn: 265364
2016-04-04 23:29:43 +00:00
Faisal Vali a734ab9808 [Cxx1z-constexpr-lambda-P0170R1] Support parsing of constexpr specifier (and its inference) on lambda expressions
Support the constexpr specifier on lambda expressions - and support its inference from the lambda call operator's body.

i.e.
  auto L = [] () constexpr { return 5; };
  static_assert(L() == 5); // OK
  auto Implicit = [] (auto a) { return a; };
  static_assert(Implicit(5) == 5); 

We do not support evaluation of lambda's within constant expressions just yet.

Implementation Strategy:
  - teach ParseLambdaExpressionAfterIntroducer to expect a constexpr specifier and mark the invented function call operator's declarator's decl-specifier with it; Have it emit fixits for multiple decl-specifiers (mutable or constexpr) in this location.
  - for cases where constexpr is not explicitly specified, have buildLambdaExpr check whether the invented function call operator satisfies the requirements of a constexpr function, by calling CheckConstexprFunctionDecl/Body.

Much obliged to Richard Smith for his patience and his care, in ensuring the code is clang-worthy.

llvm-svn: 264513
2016-03-26 16:11:37 +00:00
Richard Smith 01694c340d P0184R0: Allow types of 'begin' and 'end' expressions in range-based for loops to differ.
llvm-svn: 263895
2016-03-20 10:33:40 +00:00
Matt Arsenault c477f48f03 Update for new argument to scalbn
llvm-svn: 263371
2016-03-13 05:12:47 +00:00
Richard Smith 872307e2ac P0017R1: In C++1z, an aggregate class can have (public non-virtual) base classes; these are initialized as if they were data members.
llvm-svn: 262963
2016-03-08 22:17:41 +00:00
David Majnemer e9807b28af [MSVC Compat] Don't evaluate member base expressions w/o side effects
A member expression's base doesn't always have an impact on what the
member decl would evaluate to.  In such a case, the base is used as a
poor man's scope qualifier.

This fixes PR26738.

Differential Revision: http://reviews.llvm.org/D17619

llvm-svn: 261975
2016-02-26 04:23:19 +00:00
Andrey Bokhanko 5f6588ec2d PR26449: Fixes for bugs in __builtin_classify_type implementation
This patch fixes the following bugs in __builtin_classify_type implementation:
1) Support for member functions and fields
2) Same behavior as GCC in C mode (specifically, return integer_type_class for
   enums and pointer_type_class for function pointers and arrays). Behavior in
   C++ mode didn't changed.

Also, it refactors the whole implementation, by replacing a sequence of
if-else-if with a couple of switches.

Differential Revision: http://reviews.llvm.org/D16846

llvm-svn: 260881
2016-02-15 10:39:04 +00:00
Olivier Goffart 8bc0caa2e9 Fix ICE with constexpr and friend functions
Fix a crash while parsing this code:

  struct X  {
    friend constexpr int foo(X*) { return 12; }
    static constexpr int j = foo(static_cast<X*>(nullptr));
  };

Differential Revision: http://reviews.llvm.org/D16973

llvm-svn: 260675
2016-02-12 12:34:44 +00:00
Rui Ueyama 83aa97941f Update for LLVM function name change.
llvm-svn: 257802
2016-01-14 21:00:27 +00:00
George Burgess IV df1ed0099b [Bugfix] Fix ICE on constexpr vector splat.
In {CG,}ExprConstant.cpp, we weren't treating vector splats properly.
This patch makes us treat splats more properly.

Additionally, this patch adds a new cast kind which allows a bool->int
cast to result in -1 or 0, instead of 1 or 0 (for true and false,
respectively), so we can sanely model OpenCL bool->int casts in the AST.

Differential Revision: http://reviews.llvm.org/D14877

llvm-svn: 257559
2016-01-13 01:52:39 +00:00
James Y Knight 7281c357b1 [TrailingObjects] Convert OffsetOfExpr.
That necessitated moving the OffsetOfNode class out of OffsetOfExpr.

llvm-svn: 256590
2015-12-29 22:31:18 +00:00
George Burgess IV 533ff009ff Clean ExprConstant/CGExprConstant up a bit. NFC.
llvm-svn: 255314
2015-12-11 00:23:35 +00:00
Richard Smith ce8eca578d Explicitly permit undefined behavior in constant initializers for global
variables in C, in the cases where we can constant-fold it to a value
regardless (such as floating-point division by zero and signed integer
overflow). Strictly enforcing this rule breaks too much code.

llvm-svn: 254992
2015-12-08 03:21:47 +00:00
Richard Smith 5c40f09b3d Don't assert if evaluation of an expression that we're syntactically required
to treat as an ICE results in undefined behavior. Instead, return the "natural"
result of the operation (signed wraparound / inf / nan).

llvm-svn: 254699
2015-12-04 03:00:44 +00:00
Richard Smith 0c6124ba82 PR17381: Treat undefined behavior during expression evaluation as an unmodeled
side-effect, so that we don't allow speculative evaluation of such expressions
during code generation.

This caused a diagnostic quality regression, so fix constant expression
diagnostics to prefer either the first "can't be constant folded" diagnostic or
the first "not a constant expression" diagnostic depending on the kind of
evaluation we're doing. This was always the intent, but didn't quite work
correctly before.

This results in certain initializers that used to be constant initializers to
no longer be; in particular, things like:

  float f = 1e100;

are no longer accepted in C. This seems appropriate, as such constructs would
lead to code being executed if sanitizers are enabled.

llvm-svn: 254574
2015-12-03 01:36:22 +00:00
George Burgess IV 3e3bb95b69 Add the `pass_object_size` attribute to clang.
`pass_object_size` is our way of enabling `__builtin_object_size` to
produce high quality results without requiring inlining to happen
everywhere.

A link to the design doc for this attribute is available at the
Differential review link below.

Differential Revision: http://reviews.llvm.org/D13263

llvm-svn: 254554
2015-12-02 21:58:08 +00:00
Alexey Bataev f763027f04 [MSVC] 'property' with an empty array in array subscript expression.
MSVC supports 'property' attribute and allows to apply it to the declaration of an empty array in a class or structure definition.
For example:
```
__declspec(property(get=GetX, put=PutX)) int x[];
```
The above statement indicates that x[] can be used with one or more array indices. In this case, i=p->x[a][b] will be turned into i=p->GetX(a, b), and p->x[a][b] = i will be turned into p->PutX(a, b, i);
Differential Revision: http://reviews.llvm.org/D13336

llvm-svn: 254067
2015-11-25 12:01:00 +00:00
Benjamin Kramer 5b4296af77 Move global classes into anonymous namespaces. NFC.
llvm-svn: 251528
2015-10-28 17:16:26 +00:00
Richard Smith 9f690bd80b [coroutines] Creation of promise object, lookup of operator co_await, building
of await_* calls, and AST representation for same.

llvm-svn: 251387
2015-10-27 06:02:45 +00:00
George Burgess IV a51c4077c5 Make __builtin_object_size more conservative
r246877 made __builtin_object_size substantially more aggressive with
unknown bases if Type=1 or Type=3, which causes issues when we encounter
code like this:

struct Foo {
  int a;
  char str[1];
};

const char str[] = "Hello, World!";
struct Foo *f = (struct Foo *)malloc(sizeof(*f) + strlen(str));
strcpy(&f->str, str);

__builtin_object_size(&f->str, 1) would hand back 1, which is
technically correct given the type of Foo, but the type of Foo lies to
us about how many bytes are available in this case.

This patch adds support for this "writing off the end" idiom -- we now
answer conservatively when we're given the address of the very last
member in a struct.

Differential Revision: http://reviews.llvm.org/D12169

llvm-svn: 250488
2015-10-16 01:49:01 +00:00
Craig Topper 9798b931fa Pass ArrayRef by value. NFC.
llvm-svn: 248773
2015-09-29 04:30:05 +00:00
Nico Weber 9677562c8f Don't crash when passing &@selector to a _Nonnull parameter. Fixes PR24774.
The root cause here is that ObjCSelectorExpr is an rvalue, yet it can have its
address taken.  That's kind of awkward, but fixing this is awkward in other
ways, see https://llvm.org/bugs/show_bug.cgi?id=24774#c16 .  For now, just
fix the crash.

llvm-svn: 247740
2015-09-15 23:17:17 +00:00
George Burgess IV b40cd567c3 Fix a bug in __builtin_object_size cast removal
Apparently there are many cast kinds that may cause implicit pointer
arithmetic to happen. In light of this, the cast ignoring logic
introduced in r246877 has been changed to only ignore a small set of
cast kinds, and a test for this behavior has been added.

Thanks to Richard for catching this before it became a bug report. :)

llvm-svn: 246890
2015-09-04 22:36:18 +00:00
George Burgess IV 3a03fabdd0 Increase accuracy of __builtin_object_size.
Improvements:

- For all types, we would give up in a case such as:
    __builtin_object_size((char*)&foo, N);
  even if we could provide an answer to
    __builtin_object_size(&foo, N);
  We now provide the same answer for both of the above examples in all
  cases.

- For type=1|3, we now support subobjects with unknown bases, as long
  as the designator is valid.

Thanks to Richard Smith for the review + design planning.

Review: http://reviews.llvm.org/D12169
llvm-svn: 246877
2015-09-04 21:28:13 +00:00
David Majnemer c378ca5043 [AST] Don't crash when comparing incomplete object
We cannot tell if an object is past-the-end if its type is incomplete.
Zero sized objects satisfy past-the-end criteria and our object might
turn out to be such an object.

This fixes PR24622.

llvm-svn: 246359
2015-08-29 08:32:55 +00:00
Richard Smith 52a980a97f PR24597: Fix in-place evaluation of call expressions to provide a proper "this"
pointer to an RVO construction of a returned object.

llvm-svn: 246263
2015-08-28 02:43:42 +00:00
Alexey Bataev 1a3320e463 [OPENMP 4.0] Initial support for array sections.
Adds parsing/sema analysis/serialization/deserialization for array sections in OpenMP constructs (introduced in OpenMP 4.0).
Currently it is allowed to use array sections only in OpenMP clauses that accepts list of expressions.
Differential Revision: http://reviews.llvm.org/D10732

llvm-svn: 245937
2015-08-25 14:24:04 +00:00
George Burgess IV bdb5b2687a Make __builtin_object_size always answer correctly
__builtin_object_size would return incorrect answers for many uses where
type=3. This fixes the inaccuracy by making us emit 0 instead of LLVM's
objectsize intrinsic.

Additionally, there are many cases where we would emit suboptimal (but
correct) answers, such as when arrays are involved. This patch fixes
some of these cases (please see new tests in test/CodeGen/object-size.c
for specifics on which cases are improved)

Resubmit of r245323 with PR24493 fixed.
Patch mostly by Richard Smith.
Differential Revision: http://reviews.llvm.org/D12000
This fixes PR15212.

llvm-svn: 245403
2015-08-19 02:19:07 +00:00
Nico Weber 19999b4816 Revert r245323, it caused PR24493.
llvm-svn: 245342
2015-08-18 20:32:55 +00:00
George Burgess IV 232c76213d Make __builtin_object_size always answer correctly
__builtin_object_size would return incorrect answers for many uses where
type=3. This fixes the inaccuracy by making us emit 0 instead of LLVM's
objectsize intrinsic.

Additionally, there are many cases where we would emit suboptimal (but
correct) answers, such as when arrays are involved. This patch fixes
some of these cases (please see new tests in test/CodeGen/object-size.c
for specifics on which cases are improved)

Patch mostly by Richard Smith.
Differential Revision: http://reviews.llvm.org/D12000
This fixes PR15212.

llvm-svn: 245323
2015-08-18 18:18:27 +00:00
David Blaikie 737260662b -Wdeprecated: Job objects are stored in a vector yet are not really copyable, make them movable instead
llvm-svn: 244829
2015-08-12 23:09:24 +00:00
Alexey Bataev 0039651304 [OPENMP] Introduced type trait "__builtin_omp_required_simd_align" for default simd alignment.
Adds type trait "__builtin_omp_required_simd_align" after discussions here http://reviews.llvm.org/D9894
Differential Revision: http://reviews.llvm.org/D10597

llvm-svn: 241237
2015-07-02 03:40:19 +00:00
Alexander Kornienko ab9db51042 Revert r240270 ("Fixed/added namespace ending comments using clang-tidy").
llvm-svn: 240353
2015-06-22 23:07:51 +00:00
Alexander Kornienko 3d9d929e42 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

  $ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
      -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
      work/llvm/tools/clang

To reduce churn, not touching namespaces spanning less than 10 lines.

llvm-svn: 240270
2015-06-22 09:47:44 +00:00
Yunzhong Gao cb77930d6b Implementing C99 partial re-initialization behavior (DR-253)
Based on previous discussion on the mailing list, clang currently lacks support
for C99 partial re-initialization behavior:
Reference: http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-April/029188.html
Reference: http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_253.htm

This patch attempts to fix this problem.

Given the following code snippet,

struct P1 { char x[6]; };
struct LP1 { struct P1 p1; };

struct LP1 l = { .p1 = { "foo" }, .p1.x[2] = 'x' };
// this example is adapted from the example for "struct fred x[]" in DR-253;
// currently clang produces in l: { "\0\0x" },
//   whereas gcc 4.8 produces { "fox" };
// with this fix, clang will also produce: { "fox" };


Differential Review: http://reviews.llvm.org/D5789

llvm-svn: 239446
2015-06-10 00:27:52 +00:00
Jonathan Roelofs 104cbf9c32 Fix PR21945: Crash in constant evaluator.
Patch by Косов Евгений!

llvm-svn: 238758
2015-06-01 16:23:08 +00:00
Richard Smith 419bd09415 PR23373: A defaulted union copy constructor that is not trivial must still be
emitted as a memcpy.

llvm-svn: 236142
2015-04-29 19:26:57 +00:00
Benjamin Kramer 8407df72a3 Make helper functions static. NFC.
Found by -Wmissing-prototypes.

llvm-svn: 231668
2015-03-09 16:47:52 +00:00
Petar Jovanovic d55ae6ba37 Add support for generating MIPS legacy NaN
Currently, the NaN values emitted for MIPS architectures do not cover
non-IEEE754-2008 compliant case. This change fixes the issue.

Patch by Vladimir Radosavljevic.

Differential Revision: http://reviews.llvm.org/D7882

llvm-svn: 230653
2015-02-26 18:19:22 +00:00
Aaron Ballman 673476684e Removing LLVM_EXPLICIT, as MSVC 2012 was the last reason for requiring the macro. NFC; Clang edition.
llvm-svn: 229336
2015-02-15 22:00:28 +00:00
Josh Magee 4d1a79b8c0 Catch more cases when diagnosing integer-constant-expression overflows.
When visiting AssignmentOps, keep evaluating after a failure (when possible) in
order to identify overflow in subexpressions.

Differential Revision: http://reviews.llvm.org/D1238

llvm-svn: 228202
2015-02-04 21:50:20 +00:00
Richard Smith 513955c487 Support constant evaluation for member calls on std::initializer_list
temporaries.

llvm-svn: 224449
2014-12-17 19:24:30 +00:00
Nick Lewycky f0202ca775 Improve handling of value dependent expressions in __attribute__((enable_if)), both in the condition expression and at the call site. Fixes PR20988!
llvm-svn: 224320
2014-12-16 06:12:01 +00:00
David Majnemer 8c92b87cd0 AST: Limit zero-sized constexpr behavior to array types
Restricting this "extension" to array types maximizes our standards
conformance while not miscompiling real-world programs.

llvm-svn: 224215
2014-12-14 08:40:47 +00:00
David Majnemer 27db35878d AST: Incomplete types might be zero sized
Comparing the address of an object with an incomplete type might return
true with a 'distinct' object if the former has a size of zero.
However, such an object should compare unequal with null.

llvm-svn: 224040
2014-12-11 19:36:24 +00:00
David Majnemer b511603281 AST: Don't assume two zero sized objects live at different addresses
Zero sized objects may overlap with each other or any other object.

This fixes PR21786.

llvm-svn: 223852
2014-12-09 23:32:34 +00:00
Anastasia Stulova 5d8ad8a7b8 [OpenCL] Implemented restrictions for pointer conversions specified in OpenCL v2.0.
OpenCL v2.0 s6.5.5 restricts conversion of pointers to different address spaces:
- the named address spaces (__global, __local, and __private) => __generic - implicitly converted;
- __generic => named - with an explicit cast;
- named <=> named - disallowed;
- __constant <=> any other - disallowed.

llvm-svn: 222834
2014-11-26 15:36:41 +00:00
Richard Smith be6dd818fb Fix bug where a trivial constexpr copy/move operation couldn't copy from an
empty non-constexpr object. Such a copy doesn't break any of the constexpr
rules.

llvm-svn: 222387
2014-11-19 21:27:17 +00:00
Richard Smith 98710fc4f5 Fix assert/crash on invalid with __builtin_constant_p conditionals in constant expressions.
llvm-svn: 221942
2014-11-13 23:03:19 +00:00
Richard Smith 0f0af19b05 [c++1z] N4295: fold-expressions.
This is a new form of expression of the form:

  (expr op ... op expr)

where one of the exprs is a parameter pack. It expands into

  (expr1 op (expr2onwards op ... op expr))

(and likewise if the pack is on the right). The non-pack operand can be
omitted; in that case, an empty pack gives a fallback value or an error,
depending on the operator.

llvm-svn: 221573
2014-11-08 05:07:16 +00:00
Kaelyn Takata e1f49d545d Add the initial TypoExpr AST node for delayed typo correction.
llvm-svn: 220692
2014-10-27 18:07:20 +00:00
Richard Smith d20f1e6dd3 PR21327 / C++ DR1652 / C++ DR73: comparing a past-the-end pointer for one
complete object to a pointer to the start of another complete object does
not evaluate to the constant 'false'. All other comparisons between the
addresses of subobjects of distinct complete objects still do.

llvm-svn: 220343
2014-10-21 23:01:04 +00:00
Chandler Carruth b29a743891 [complex] Teach the other two binary operators on complex numbers (==
and !=) to support mixed complex and real operand types.

This requires removing an assert from SemaChecking, and adding support
both to the constant evaluator and the code generator to synthesize the
imaginary part when needed. This seemed somewhat cleaner than having
just the comparison operators force real-to-complex conversions.

I've added test cases for these operations. I'm really terrified that
there were *no* tests in-tree which exercised this.

This turned up when trying to build R after my change to the complex
type lowering.

llvm-svn: 219570
2014-10-11 11:03:30 +00:00
Chandler Carruth a216cad0fc [complex] Teach Clang to preserve different-type operands to arithmetic
operators where one type is a C complex type, and to emit both the
efficient and correct implementation for complex arithmetic according to
C11 Annex G using this extra information.

For both multiply and divide the old code was writing a long-hand
reduced version of the math without any of the special handling of inf
and NaN recommended by the standard here. Instead of putting more
complexity here, this change does what GCC does which is to emit
a libcall for the fully general case.

However, the old code also failed to do the proper minimization of the
set of operations when there was a mixed complex and real operation. In
those cases, C provides a spec for much more minimal operations that are
valid. Clang now emits the exact suggested operations. This change isn't
*just* about performance though, without minimizing these operations, we
again lose the correct handling of infinities and NaNs. It is critical
that this happen in the frontend based on assymetric type operands to
complex math operations.

The performance implications of this change aren't trivial either. I've
run a set of benchmarks in Eigen, an open source mathematics library
that makes heavy use of complex. While a few have slowed down due to the
libcall being introduce, most sped up and some by a huge amount: up to
100% and 140%.

In order to make all of this work, also match the algorithm in the
constant evaluator to the one in the runtime library. Currently it is
a broken port of the simplifications from C's Annex G to the long-hand
formulation of the algorithm.

Splitting this patch up is very hard because none of this works without
the AST change to preserve non-complex operands. Sorry for the enormous
change.

Follow-up changes will include support for sinking the libcalls onto
cold paths in common cases and fastmath improvements to allow more
aggressive backend folding.

Differential Revision: http://reviews.llvm.org/D5698

llvm-svn: 219557
2014-10-11 00:57:18 +00:00
Alexey Bataev ec4747802a Fix for bug http://llvm.org/PR17427.
Assertion failed: "Computed __func__ length differs from type!"
Reworked PredefinedExpr representation with internal StringLiteral field for function declaration.
Differential Revision: http://reviews.llvm.org/D5365

llvm-svn: 219393
2014-10-09 08:45:04 +00:00
Hal Finkel 0dd05d4b59 constexpr evaluation for __builtin_assume_aligned
Richard noted in the review of r217349 that extra handling of
__builtin_assume_aligned inside of the expression evaluator was needed. He was
right, and this should address the concerns raised, namely:

 1. The offset argument to __builtin_assume_aligned can have side effects, and
    we need to make sure that all arguments are properly evaluated.

 2. If the alignment assumption does not hold, that introduces undefined
    behavior, and undefined behavior cannot appear inside a constexpr.

and hopefully the diagnostics produced are detailed enough to explain what is
going on.

llvm-svn: 218992
2014-10-03 17:18:37 +00:00
Hal Finkel 92b9b49f61 Revert useless part of r217349
Adding handling of __builtin_assume_aligned to IntExprEvaluator does not make
sense because __builtin_assume_aligned returns a pointer (not an integer).
Thanks to Richard for figuring out why this was not doing anything.

I'll add this back in a better place (PointerExprEvaluator perhaps).

llvm-svn: 218958
2014-10-03 04:46:46 +00:00
Fariborz Jahanian a3d8879be7 Fix evatuated value of __builtin_object_size according to its
'type'  argument when it cannot be determined which objects ptr 
points to at compile time. rdar://18334276

llvm-svn: 218258
2014-09-22 17:11:59 +00:00
Richard Smith b01fe40c07 Reject a slightly-sneaky way to perform a read of mutable state from within a
constexpr function. Part of this fix is a tentative fix for an as-yet-unfiled
core issue (we're missing a prohibition against reading mutable members from
unions via a trivial constructor/assignment, since that doesn't perform an
lvalue-to-rvalue conversion on the members).

llvm-svn: 217852
2014-09-16 01:24:02 +00:00
Hal Finkel bcc06085a8 Add __builtin_assume and __builtin_assume_aligned using @llvm.assume.
This makes use of the recently-added @llvm.assume intrinsic to implement a
__builtin_assume(bool) intrinsic (to provide additional information to the
optimizer). This hooks up __assume in MS-compatibility mode to mirror
__builtin_assume (the semantics have been intentionally kept compatible), and
implements GCC's __builtin_assume_aligned as assume((p - o) & mask == 0). LLVM
now contains special logic to deal with assumptions of this form.

llvm-svn: 217349
2014-09-07 22:58:14 +00:00
Craig Topper 5fc8fc2d31 Simplify creation of a bunch of ArrayRefs by using None, makeArrayRef or just letting them be implicitly created.
llvm-svn: 216528
2014-08-27 06:28:36 +00:00
Aaron Ballman dd69ef38db C++1y is now C++14!
Changes diagnostic options, language standard options, diagnostic identifiers, diagnostic wording to use c++14 instead of c++1y. It also modifies related test cases to use the updated diagnostic wording.

llvm-svn: 215982
2014-08-19 15:55:55 +00:00
Richard Smith 77be48ac47 PR18097: Support initializing an _Atomic(T) from an object of C++ class type T
or a class derived from T. We already supported this when initializing
_Atomic(T) from T for most (and maybe all) other reasonable values of T.

llvm-svn: 214390
2014-07-31 06:31:19 +00:00
Richard Smith 33b44ab2b7 Replace r213816's fix with a different one. It's not meaningful to call
isOnePastTheEnd on an invalid designator, so assert and push the check into the
one caller that wasn't already checking.

llvm-svn: 213820
2014-07-23 23:50:25 +00:00
Reid Kleckner 142dd46c2a Add a missing Invalid check to SubobjectDesignator::isOnePastEnd()
The class seems to have an invariant that Entries is non-empty if
Invalid is false.  It appears this method was previously private, and
all internal uses checked Invalid.  Now there is an external caller, so
check Invalid to avoid array OOB underflow.

Fixes PR20420.

llvm-svn: 213816
2014-07-23 23:24:25 +00:00
Hal Finkel a8443c36ae Handle __assume in the VoidExprEvaluator
This is a follow-up to an IRC conversation with Richard last night; __assume
does not evaluate its argument, and so the argument should not contribute to
whether (__assume(e), constant) can be used where a constant is required.

llvm-svn: 213267
2014-07-17 14:49:58 +00:00
Anders Carlsson 1a9fe3d4db Handle __builtin_clzs and __builtin_ctzs in the constant expression evaluator.
llvm-svn: 212464
2014-07-07 15:53:44 +00:00
Richard Smith 22a5d61b5d Add an explicit diagnostic for the case where an expression is not a constant
expression because it uses 'this'. Inspired by PR20219 comment#2.

llvm-svn: 212433
2014-07-07 06:00:13 +00:00
Craig Topper 00bbdcf9b3 Remove llvm:: from uses of ArrayRef.
llvm-svn: 211987
2014-06-28 23:22:23 +00:00
Hans Wennborg 82dd877e8a Don't allow dllimport variables in constant initializers
This is a follow-up to David's r211677. For the following code,
we would end up referring to 'foo' in the initializer for 'arr',
and then fail to link, because 'foo' is dllimport and needs to be
accessed through the __imp_?foo.

  __declspec(dllimport) extern const char foo[];
  const char* f() {
    static const char* const arr[] = { foo };
    return arr[0];
  }

Differential Revision: http://reviews.llvm.org/D4299

llvm-svn: 211736
2014-06-25 22:19:48 +00:00
David Majnemer 0c43d8077e AST: Initialization with dllimport functions in C
The C++ language requires that the address of a function be the same
across all translation units.  To make __declspec(dllimport) useful,
this means that a dllimported function must also obey this rule.  MSVC
implements this by dynamically querying the import address table located
in the linked executable.  This means that the address of such a
function in C++ is not constant (which violates other rules).

However, the C language has no notion of ODR nor does it permit dynamic
initialization whatsoever.  This requires implementations to _not_
dynamically query the import address table and instead utilize a wrapper
function that will be synthesized by the linker which will eventually
query the import address table.  The effect this has is, to say the
least, perplexing.

Consider the following C program:
__declspec(dllimport) void f(void);

typedef void (*fp)(void);

static const fp var = &f;

const fp fun() { return &f; }

int main() { return fun() == var; }

MSVC will statically initialize "var" with the address of the wrapper
function and "fun" returns the address of the actual imported function.
This means that "main" will return false!

Note that LLVM's optimizers are strong enough to figure out that "main"
should return true.  However, this result is dependent on having
optimizations enabled!

N.B.  This change also permits the usage of dllimport declarators inside
of template arguments; they are sufficiently constant for such a
purpose.  Add tests to make sure we don't regress here.

llvm-svn: 211677
2014-06-25 08:15:07 +00:00
David Majnemer 11a54c3465 AST: Address of dllimport functions isn't constant
The address of dllimport functions can be accessed one of two ways:
- Through the IAT which is symbolically referred to with a symbol
  starting with __imp_.
- Via the wrapper-function which ends up calling through the __imp_
  symbol.

The problem with using the wrapper-function is that it's address will
not compare as equal in all translation units.  Specifically, it will
compare unequally with the translation unit which defines the function.

This fixes PR19955.

llvm-svn: 211570
2014-06-24 06:40:51 +00:00
David Majnemer c28a964cba AST: Address of dllimport variables isn't constant
The address of dllimport variables isn't something that can be
meaningfully used in a constexpr context and isn't suitable for
evaluation at load-time.  They require loads from memory to properly
evaluate.

This fixes PR19955.

Differential Revision: http://reviews.llvm.org/D4250

llvm-svn: 211568
2014-06-24 05:59:13 +00:00
Richard Smith 3e79a57a6d Add missing "non-constant" diagnostic for a member call on a temporary of
non-literal class type.

llvm-svn: 210696
2014-06-11 19:53:12 +00:00
Richard Smith f6d7030f0f Related to PR19992: when the GNU alignof-expression extension is applied to an
expression of array-of-unknown-bound type, don't try to complete the array
bound, and return the alignment of the element type rather than 1.

llvm-svn: 210608
2014-06-10 23:34:28 +00:00
Craig Topper 36250ad632 [C++11] Use 'nullptr'. AST edition.
llvm-svn: 208517
2014-05-12 05:36:57 +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
Aaron Ballman c7e4e219b5 [C++11] Replacing CompoundStmt iterators body_begin() and body_end() with iterator_range body(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 204040
2014-03-17 14:19:37 +00:00
James Dennett 0492ef0e0b Fix a crash (assertion failure) in EvaluateAsRValue.
Summary:
Gracefully fail to evaluate a constant expression if its type is
unknown, rather than failing an assertion trying to access the type.

Reviewers: klimek

Reviewed By: klimek

CC: chandlerc, cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D3075

llvm-svn: 203950
2014-03-14 17:44:10 +00:00
Aaron Ballman 535bbcccb1 [C++11] Replacing DeclStmt iterators decl_begin() and decl_end() with iterator_range decls(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203947
2014-03-14 17:01:24 +00:00
Aaron Ballman 0ad78303de [C++11] Replacing CXXRecordDecl iterators init_begin() and init_end() with iterator_range inits(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203819
2014-03-13 17:34:31 +00:00
Aaron Ballman 62e47c423d Reverting llvm::distance changes to use std::distance with iterators instead, per post-commit review feedback.
Replacing llvm::copy changes with SmallVector range-based construction which is a considerably cleaner approach.

llvm-svn: 203461
2014-03-10 13:43:55 +00:00
Aaron Ballman e8a8baef44 [C++11] Replacing RecordDecl iterators field_begin() and field_end() with iterator_range fields(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203355
2014-03-08 20:12:42 +00:00
Aaron Ballman 29c9460d3e Renaming the chains() ranged iterator to chain() per suggestion by Richard Smith.
llvm-svn: 203262
2014-03-07 18:36:15 +00:00
Aaron Ballman 1391608234 [C++11] Replacing IndirectFieldDecl iterators chain_begin() and chain_end() with iterator_range chains(). Updating all of the usages of the iterators with range-based for loops.
llvm-svn: 203261
2014-03-07 18:11:58 +00:00
Richard Smith da3f4fd3fe PR19010: Make sure we initialize (empty) indirect base class subobjects when
evaluating trivial default initialization of a literal class type.

llvm-svn: 203025
2014-03-05 23:32:50 +00:00
Argyrios Kyrtzidis 3d9e38273b [AST] Follow-up for r201468, move the check to the caller and add an assertion.
Suggested by Richard Smith.

llvm-svn: 201753
2014-02-20 04:00:01 +00:00
Argyrios Kyrtzidis 90181d6180 [Sema] Fix assertion hit while trying to do constant evaluation for a dependent expression
inside a GNU statement expression.

rdar://16064952

llvm-svn: 201468
2014-02-15 18:53:57 +00:00
Richard Smith f137f9317b PR18283: If a const variable of integral or enumeration type is
initialized from a constant expression in C++98, it can be used in
constant expressions, even if it was brace-initialized. Patch by
Rahul Jain!

llvm-svn: 200098
2014-01-25 20:50:08 +00:00
Alp Toker 314cc81b8c Rename getResultType() on function and method declarations to getReturnType()
A return type is the declared or deduced part of the function type specified in
the declaration.

A result type is the (potentially adjusted) type of the value of an expression
that calls the function.

Rule of thumb:

  * Declarations have return types and parameters.
  * Expressions have result types and arguments.

llvm-svn: 200082
2014-01-25 16:55:45 +00:00
Nick Lewycky 35a6ef4c35 Add a new attribute 'enable_if' which can be used to control overload resolution based on the values of the function arguments at the call site.
llvm-svn: 198996
2014-01-11 02:50:57 +00:00
Aaron Ballman 68af21c975 Fixing a FIXME; the RetTy template parameter is always bool in practice, and so it has been removed. No functional changes intended.
llvm-svn: 198440
2014-01-03 19:26:43 +00:00
Alp Toker 95e7ff2ed1 Eliminate UnaryTypeTraitExpr
Remove UnaryTypeTraitExpr and switch all remaining type trait related handling
over to TypeTraitExpr.

The UTT/BTT/TT enum prefix and evaluation code is retained pending further
cleanup.

This is part of the ongoing work to unify type traits following the removal of
BinaryTypeTraitExpr in r197273.

llvm-svn: 198271
2014-01-01 05:57:51 +00:00
Alp Toker a724cff01b Rename isBuiltinCall() to getBuiltinCallee()
This better describes what the function does.

Cleanup only.

llvm-svn: 198127
2013-12-28 21:59:02 +00:00
Alp Toker cbb9034e2a Eliminate BinaryTypeTraitExpr
There's nothing special about type traits accepting two arguments.

This commit eliminates BinaryTypeTraitExpr and switches all related handling
over to TypeTraitExpr.

Also fixes a CodeGen failure with variadic type traits appearing in a
non-constant expression.

The BTT/TT prefix and evaluation code is retained as-is for now but will soon
be further cleaned up.

This is part of the ongoing work to unify type traits.

llvm-svn: 197273
2013-12-13 20:49:58 +00:00
David Tweed e1468322eb Add front-end infrastructure now address space casts are in LLVM IR.
With the introduction of explicit address space casts into LLVM, there's
a need to provide a new cast kind the front-end can create for C/OpenCL/CUDA
and code to produce address space casts from those kinds when appropriate.

Patch by Michele Scandale!

llvm-svn: 197036
2013-12-11 13:39:46 +00:00
Richard Smith e6c19f22b2 Modern gcc is happy to constant evaluate __builtin_strlen in various cases
where we didn't. Extend our constant evaluation for __builtin_strlen to handle
any constant array of chars, not just string literals, to match.

llvm-svn: 194762
2013-11-15 02:10:04 +00:00
Richard Smith 9ff62af3aa PR17615: A delegating constructor initializer is a full-expression. Don't
forget to clean up temporaries at the end of it.

llvm-svn: 194213
2013-11-07 18:45:03 +00:00
Aaron Ballman f682f53012 Silencing some MSVC warnings about not all control paths returning a value when they actually do.
llvm-svn: 194156
2013-11-06 18:15:02 +00:00
Richard Smith 4e66f1faa1 More constant evaluation cleanup, and fix an issue where we'd override an
earlier 'non-constant' diagnostic with a later one if the earlier one was from
a side-effect we thought we could evaluate past.

llvm-svn: 194117
2013-11-06 02:19:10 +00:00
Richard Smith e9ff770f8b Simplify: we don't care why constant evaluation might have failed when we're
checking an expression for constant overflow.

llvm-svn: 194099
2013-11-05 22:23:30 +00:00
Richard Smith 6d4c6586c9 Refactor constant expression handling and make a couple of tweaks to make it a
bit more robust against future changes. This includes a slight diagnostic
improvement: if we know we're only trying to form a constant expression, take
the first diagnostic which shows the expression is not a constant expression,
rather than preferring the first one which makes the expression unfoldable.

llvm-svn: 194098
2013-11-05 22:18:15 +00:00
Richard Smith ea3019d23a Add constant evaluation support for __builtin_isinf, __builtin_isfinite,
__builtin_isnan, and __builtin_isnormal. Patch by Karthik Bhat! Tests by me.

llvm-svn: 192729
2013-10-15 19:07:14 +00:00
Nick Lewycky e2b2caaded Fix comment to match name of variable.
llvm-svn: 191171
2013-09-22 10:07:22 +00:00
Hal Finkel c4d7c82c7f Add the intrinsic __builtin_convertvector
LLVM supports applying conversion instructions to vectors of the same number of
elements (fptrunc, fptosi, etc.) but there had been no way for a Clang user to
cause such instructions to be generated when using builtin vector types.

C-style casting on vectors is already defined in terms of bitcasts, and so
cannot be used for these conversions as well (without leading to a very
confusing set of semantics). As a result, this adds a __builtin_convertvector
intrinsic (patterned after the OpenCL __builtin_astype intrinsic). This is
intended to aid the creation of vector intrinsic headers that create generic IR
instead of target-dependent intrinsics (in other words, this is a generic
_mm_cvtepi32_ps). As noted in the documentation, the action of
__builtin_convertvector is defined in terms of the action of a C-style cast on
each vector element.

llvm-svn: 190915
2013-09-18 03:29:45 +00:00
Eli Friedman 1409e6e7c6 Fix const-eval of vector init-lists of a vector.
Like any other type, an init list for a vector can have the same type as
the vector itself; handle that case.

<rdar://problem/14990460>

llvm-svn: 190844
2013-09-17 04:07:02 +00:00
Richard Smith 17e32460ed Part three of PR15721: if we have an invalid CXXDefaultInitExpr, don't crash if
we try to constant-evaluate it. Patch by Karthik Bhat, test by me.

llvm-svn: 190722
2013-09-13 20:51:45 +00:00
Richard Smith 84c6b3d293 PR5683: Issue a warning when subtracting pointers to types of zero size, and
treat such subtractions as being non-constant. Patch by Serge Pavlov! With a
few tweaks by me.

llvm-svn: 190439
2013-09-10 21:34:14 +00:00
Eli Friedman 0718591771 Adjust clang for change to APFloat::toString.
I changed the diagnostic printing code because it's probably better
to cut off a digit from DBL_MAX than to print something like
1.300000001 when the user wrote 1.3.

llvm-svn: 189625
2013-08-29 23:44:43 +00:00
Craig Topper a31a882f87 Constify more uses of ASTContext&. No functional change.
llvm-svn: 188991
2013-08-22 07:09:37 +00:00
Richard Smith 49ca8aab58 PR16755: When initializing or modifying a bitfield member in a constant
expression, truncate the stored value to the size of the bitfield.

llvm-svn: 187782
2013-08-06 07:09:20 +00:00
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
Eli Friedman 75807f239e Make IgnoreParens() look through ChooseExprs.
This is the same way GenericSelectionExpr works, and it's generally a
more consistent approach.

A large part of this patch is devoted to caching the value of the condition
of a ChooseExpr; it's needed to avoid threading an ASTContext into
IgnoreParens().

Fixes <rdar://problem/14438917>.

llvm-svn: 186738
2013-07-20 00:40:58 +00:00
Richard Smith 6cbd65d84d Add a __builtin_addressof that performs the same functionality as the built-in
& operator (ignoring any overloaded operator& for the type). The purpose of
this builtin is for use in std::addressof, to allow it to be made constexpr;
the existing implementation technique (reinterpret_cast to some reference type,
take address, reinterpert_cast back) does not permit this because
reinterpret_cast between reference types is not permitted in a constant
expression in C++11 onwards.

llvm-svn: 186053
2013-07-11 02:27:57 +00:00
Richard Smith 51f0317e52 PR16377: Allow evaluation of statement expressions in constant evaluation,
why not. Apparently GCC supports this.

llvm-svn: 184396
2013-06-20 03:00:05 +00:00
Richard Smith 1a90f5956d PR14503: Don't assert if a constexpr constructor temploid instantiates to a
constructor that does not initialize all members, and that constructor is used
to initialize a global.

llvm-svn: 184211
2013-06-18 17:51:51 +00:00
Richard Smith a509f2fdfa Emit initializers for static-storage-duration temporaries as constants where
possible.

llvm-svn: 183967
2013-06-14 03:07:01 +00:00
Richard Smith ab341c62b3 More for PR12457: fix handling of __builtin_isinf_sign and test.
llvm-svn: 183890
2013-06-13 06:31:13 +00:00
Richard Smith 8889a3d3b5 Towards PR12457: constant expression evaluation support for __builtin_parity{,l,ll}, __builtin_ffs{,l,ll}, and __builtin_fpclassify.
llvm-svn: 183889
2013-06-13 06:26:32 +00:00
Richard Smith 80b3c8e32f Fix part of PR12457. Patch by Justin Bogner!
llvm-svn: 183886
2013-06-13 05:04:16 +00:00
Richard Smith cc1b96d356 PR12086, PR15117
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).

This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.

llvm-svn: 183872
2013-06-12 22:31:48 +00:00
Richard Smith ea4ad5d841 When a static storage duration temporary appears in a constant expression, it
must be initialized by a constant expression (not just a core constant
expression), because we're going to emit it as a global. Core issue for this is
pending.

llvm-svn: 183388
2013-06-06 08:19:16 +00:00
Richard Smith e6c0144208 Model temporary lifetime-extension explicitly in the AST. Use this model to
handle temporaries which have been lifetime-extended to static storage duration
within constant expressions. This correctly handles nested lifetime extension
(through reference members of aggregates in aggregate initializers) but
non-constant-expression emission hasn't yet been updated to do the same.

llvm-svn: 183283
2013-06-05 00:46:14 +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 a23ab514c2 PR14772: Support constant expression evaluation for _Atomic types.
* Treat _Atomic(T) as a literal type if T is a literal type.
 * Evaluate expressions of this type properly.
 * Fix a lurking bug where we built completely bogus ASTs for converting to
   _Atomic types in C++ in some cases, caught by the tests for this change.

llvm-svn: 182541
2013-05-23 00:30:41 +00:00
Richard Smith 37dc92eb4c Tidy up now that PointerUnion has an operator== that works.
llvm-svn: 181983
2013-05-16 05:04:51 +00:00
David Blaikie 7d17010db5 Use only explicit bool conversion operator
The most common (non-buggy) case are where such objects are used as
return expressions in bool-returning functions or as boolean function
arguments. In those cases I've used (& added if necessary) a named
function to provide the equivalent (or sometimes negative, depending on
convenient wording) test.

DiagnosticBuilder kept its implicit conversion operator owing to the
prevalent use of it in return statements.

One bug was found in ExprConstant.cpp involving a comparison of two
PointerUnions (PointerUnion did not previously have an operator==, so
instead both operands were converted to bool & then compared). A test
is included in test/SemaCXX/constant-expression-cxx1y.cpp for the fix
(adding operator== to PointerUnion in LLVM).

llvm-svn: 181869
2013-05-15 07:37:26 +00:00
Richard Smith 0838f3a1f2 Suppress bogus "use of undefined constexpr function" error if the function body
was erroneous and got discarded.

llvm-svn: 181758
2013-05-14 05:18:44 +00:00
Richard Smith f8cf9d4851 Suppress GCC warning for no return after covered switch, and remove some
debugging code from an unreachable codepath.

llvm-svn: 181731
2013-05-13 20:33:30 +00:00
Richard Smith 496ddcfba9 C++1y: support for 'switch' statements in constexpr functions. This is somewhat
inefficient; we perform a linear scan of switch labels to find the one matching
the condition, and then walk the body looking for that label. Both parts should
be straightforward to optimize.

llvm-svn: 181671
2013-05-12 17:32:42 +00:00
Richard Smith 7525ff67f1 Implement C++1y constant initializer rules: in a constant initializer for an
object x, x's subobjects can be constructed by constexpr constructor even if
they are of non-literal type, and can be read and written even though they're
not members of a constexpr object or temporary.

llvm-svn: 181506
2013-05-09 07:14:00 +00:00
Richard Smith a3d3bd215b C++1y: Add a step limit to constexpr evaluation, to catch runaway loops.
llvm-svn: 181388
2013-05-08 02:12:03 +00:00
Richard Smith 861b5b5aed C++1y constant expression evaluation: compound assignment support for floating-point and pointer types.
llvm-svn: 181376
2013-05-07 23:34:45 +00:00
Richard Smith 43e77733c2 C++1y constant expression evaluation: support for compound assignments on integers.
llvm-svn: 181287
2013-05-07 04:50:00 +00:00
Richard Smith 99005e65cd C++1y: an assignment operator is implicitly 'constexpr' if it would only call 'constexpr' assignment operators for a literal class type.
llvm-svn: 181284
2013-05-07 03:19:20 +00:00
Hans Wennborg 9242bd1b06 Add llvm_unreachable at end of fully covered switch
To pacify GCC warning about control reaching end of non-void function.

llvm-svn: 181197
2013-05-06 15:13:34 +00:00
John McCall 768439eb2e Require the containing type to be complete when we see
__alignof__ of a field.

This problem can only happen in C++11.

Also do some petty optimizations.

rdar://13784901

llvm-svn: 181185
2013-05-06 07:40:34 +00:00
Richard Smith 896e0d7568 C++1y: support range-based for loops in constant expressions.
llvm-svn: 181184
2013-05-06 06:51:17 +00:00
Richard Smith 4e18ca5200 C++1y: support 'for', 'while', and 'do ... while' in constant expressions.
llvm-svn: 181181
2013-05-06 05:56:11 +00:00
Richard Smith 243ef9077a C++1y: support for increment and decrement in constant expression evaluation.
llvm-svn: 181173
2013-05-05 23:31:59 +00:00
Richard Smith 3229b744a5 Factor out duplication between lvalue-to-rvalue conversions and variable
assignments in constant expressions. No significant functionality changes
(slight improvement to potential constant expression checking). 

llvm-svn: 181170
2013-05-05 21:17:10 +00:00
Richard Smith 9f8400eca4 PR15884: In the 'taking the address of a temporary' extension, materialize the
temporary to an lvalue before taking its address. This removes a weird special
case from the AST representation, and allows the constant expression evaluator
to deal with it without (broken) hacks.

llvm-svn: 180866
2013-05-01 19:00:39 +00:00
Benjamin Kramer 62498ab4d5 Move helper classes into anonymous namespaces.
llvm-svn: 180642
2013-04-26 22:01:47 +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 d9f663b510 C++1y constexpr extensions, round 1: Allow most forms of declaration and
statement in constexpr functions. Everything which doesn't require variable
mutation is also allowed as an extension in C++11. 'void' becomes a literal
type to support constexpr functions which return 'void'.

llvm-svn: 180022
2013-04-22 15:31:51 +00:00
Richard Smith 9543c5e371 Fix array constant expression evaluation bug: we can have different values for
different array elements, even if they're all constructed using the same
default constructor.

llvm-svn: 180017
2013-04-22 14:44:29 +00:00
Richard Smith 852c9db72b C++1y: Allow aggregates to have default initializers.
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.

There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.

llvm-svn: 179958
2013-04-20 22:23:05 +00:00
John McCall 5e77d76c95 Basic support for Microsoft property declarations and
references thereto.

Patch by Tong Shen!

llvm-svn: 179585
2013-04-16 07:28:30 +00:00
Richard Smith fd3834f7a1 Annotate flavor of TLS variable (statically or dynamically initialized) onto the AST.
llvm-svn: 179447
2013-04-13 02:43:54 +00:00
Jordan Rose b1312a5495 Force a load when creating a reference to a temporary copied from a bitfield.
For this source:
  const int &ref = someStruct.bitfield;

We used to generate this AST:

  DeclStmt [...]
  `-VarDecl [...] ref 'const int &'
    `-MaterializeTemporaryExpr [...] 'const int' lvalue
      `-ImplicitCastExpr [...] 'const int' lvalue <NoOp>
        `-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
          `-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'

Notice the lvalue inside the MaterializeTemporaryExpr, which is very
confusing (and caused an assertion to fire in the analyzer - PR15694).

We now generate this:

  DeclStmt [...]
  `-VarDecl [...] ref 'const int &'
    `-MaterializeTemporaryExpr [...] 'const int' lvalue
      `-ImplicitCastExpr [...] 'int' <LValueToRValue>
        `-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
          `-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'

Which makes a lot more sense. This allows us to remove code in both
CodeGen and AST that hacked around this special case.

The commit also makes Clang accept this (legal) C++11 code:

  int &&ref = std::move(someStruct).bitfield

PR15694 / <rdar://problem/13600396>

llvm-svn: 179250
2013-04-11 00:58:58 +00:00
Joey Gouly 0942e0b5e1 Fix a crash in OpenCL code by using the proper (RHS) bit-width.
llvm-svn: 173802
2013-01-29 15:09:40 +00:00
Fariborz Jahanian bbcf8548cb removed duplicated comment.
llvm-svn: 173378
2013-01-24 22:26:55 +00:00
Fariborz Jahanian e735ff93e8 Patch to check for integer overflow. It has been
commented on and approved by Richard Smith.

llvm-svn: 173377
2013-01-24 22:11:45 +00:00
Tim Northover 178723a687 Switch to APFloat constructor taking fltSemantics.
This change also makes the serialisation store the required semantics,
fixing an issue where PPC128 was always assumed when re-reading a
128-bit value.

llvm-svn: 173139
2013-01-22 09:46:51 +00:00
Guy Benyei 1b4fb3e08b Implement OpenCL event_t as Clang builtin type, including event_t related OpenCL restrictions (OpenCL 1.2 spec 6.9)
llvm-svn: 172973
2013-01-20 12:31:11 +00:00
Dmitri Gribenko f857950d39 Remove useless 'llvm::' qualifier from names like StringRef and others that are
brought into 'clang' namespace by clang/Basic/LLVM.h

llvm-svn: 172323
2013-01-12 19:30:44 +00:00
Fariborz Jahanian 8b115b7872 Issue warning when case value is too large to fit
in case condition type. // rdar://11577384.
Test is conditionalized on x86_64-apple triple as
I am not sure if the INT_MAX/LONG_MAX values in the test
will pass this test for other hosts.

llvm-svn: 172016
2013-01-09 23:04:56 +00:00
David Tweed 042e0883cb Scalar shifts in the OpenCL specification (as of v. 1.2) are defined to be
with respect to the lower "left-hand-side bitwidth" bits, even when negative);
see OpenCL spec 6.3j. This patch both implements this behaviour in the code
generator and "constant folding" bits of Sema, and also prevents tests
to detect undefinedness in terms of the weaker C99 or C++ specifications
from being applied. 

llvm-svn: 171755
2013-01-07 16:43:27 +00:00
Richard Smith 2bf7fdb723 s/CPlusPlus0x/CPlusPlus11/g
llvm-svn: 171367
2013-01-02 11:42:31 +00:00
Richard Smith 9e575dafad Replace magic numbers in CheckICE with an enum.
llvm-svn: 171192
2012-12-28 13:25:52 +00:00
Richard Smith 74fc72143a PR14729: Fix typo in CheckICE for BinaryConditionalOperators.
llvm-svn: 171191
2012-12-28 12:53:55 +00:00
Benjamin Kramer 444a1304ad Include pruning and general cleanup.
llvm-svn: 169095
2012-12-01 17:12:56 +00:00
Richard Smith 6f3d435c5a DR1535: only potentially-evaluated typeid expressions are disallowed in constant
expressions, not *any* typeid on a polymorphic class type.

llvm-svn: 166156
2012-10-17 23:52:07 +00:00
Benjamin Kramer a801f4a81d Expose __builtin_bswap16.
GCC has always supported this on PowerPC and 4.8 supports it on all platforms,
so it's a good idea to expose it in clang too. LLVM supports this on all targets.

llvm-svn: 165362
2012-10-06 14:42:22 +00:00
Benjamin Kramer daa0961244 CodeGen: Fix a silly typo when emitting subs of block addresses.
Part of PR14005.

llvm-svn: 165117
2012-10-03 14:15:39 +00:00
Richard Smith cdd1da209d Fix treatment of case which came up on std-proposals@: 'void' is permitted in core constant expressions, despite not being a literal type.
llvm-svn: 164968
2012-10-01 20:36:17 +00:00
Richard Smith 80ac9efec4 Allow __builtin_bswap32/64 in constant expressions, like gcc does. Patch by Tijl Coosemans!
llvm-svn: 164841
2012-09-28 20:20:52 +00:00
Richard Smith b15fe3a5e4 PR13811: Add a FunctionParmPackExpr node to handle references to function
parameter packs where the reference is not being expanded but the pack has
been. Previously, Clang would segfault in such cases.

llvm-svn: 163672
2012-09-12 00:56:43 +00:00
Eli Friedman 34866c7719 Change the representation of builtin functions in the AST
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call.  Fixes PR13195.

llvm-svn: 162962
2012-08-31 00:14:07 +00:00
Hans Wennborg cb9ad9908b Move TLS check from LValueExprEvaluator::VisitVarDecl to
CheckLValueConstantExpression.

Richard pointed out that using the address of a TLS variable is ok in a
core C++11 constant expression, as long as it isn't part of the eventual
result of constant expression evaluation. Having the check in
CheckLValueConstantExpression accomplishes this.

llvm-svn: 162850
2012-08-29 18:27:29 +00:00
Hans Wennborg 2efa2c33ec Fix r162835 as per Richard's comments.
VisitVarDecl should return Error(E), and we should test that the address
of a TLS var can't be used as a constexpr.

llvm-svn: 162837
2012-08-29 09:17:34 +00:00
Hans Wennborg 299f50b4e8 The address of a TLS var is not compile-time constant (PR13720)
This makes Clang produce an error for code such as:

  __thread int x;
  int *p = &x;

The lvalue of a thread-local variable cannot be evaluated at compile
time.

llvm-svn: 162835
2012-08-29 08:44:49 +00:00
Ted Kremenek 2883175e4c Change a bunch of cases where we do "getAs<...>->doSomething()" to
"castAs<...>->doSomething()".  The analyzer was flagging these
as potential null dereferences, which is technically true.  The
invariants appear to be that these casts should never fail, so
let's use castAs<> instead and avoid a runtime check.

llvm-svn: 162468
2012-08-23 20:46:57 +00:00
Richard Smith ef8bf4368e Factor out computation of whether a typeid's expression is potentially
evaluated into a CXXTypeid member function. No functionality change.

llvm-svn: 161779
2012-08-13 20:08:14 +00:00
Richard Smith 0421ce7b22 Teach Expr::HasSideEffects about all the Expr types, and fix a bug where it
was mistakenly classifying dynamic_casts which might throw as having no side
effects.

Switch it from a visitor to a switch, so it is kept up-to-date as future Expr
nodes are added. Move it from ExprConstant.cpp to Expr.cpp, since it's not
really related to constant expression evaluation.

Since we use HasSideEffect to determine whether to emit an unused global with
internal linkage, this has the effect of suppressing emission of globals in
some cases.

I've left many of the Objective-C cases conservatively assuming that the
expression has side-effects. I'll leave it to someone with better knowledge
of Objective-C than mine to improve them.

llvm-svn: 161388
2012-08-07 04:16:51 +00:00
Fariborz Jahanian 29489a9e9e objective-C string literal has no side-effect,
resulting in issuance of unused static variable
warning now. // rdar://10777111

llvm-svn: 161291
2012-08-04 01:24:33 +00:00
Nico Weber 9035951409 Let Expr::HasSideEffects() return false for NULL, bool literals, this, and nullptr.
Fixes PR13413, -Wunused-private-field now warns on unused fields initialized to NULL.

llvm-svn: 160541
2012-07-20 03:39:05 +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
Nuno Lopes e61e9dbf73 add support for conditional expressions in Expr::HasSideEffects()
This fixes a bug in __builtin_object_size() codegen

llvm-svn: 160191
2012-07-13 20:48:52 +00:00
Richard Smith 9fce7bc721 Fix crash when constant-evaluating a CXXConstructExpr representing
value-initialization for an array of class type with a trivial default
constructor.

llvm-svn: 160024
2012-07-10 22:12:55 +00:00
Richard Smith 1b9f2eb76b PR13290: Constant-evaluation support for CXXConstructExprs which construct a
multidimensional array of class type. Also, preserve zero-initialization when
evaluating an initializer list for an array, in case the initializers refer to
later elements (which have preceding zero-initialization).

llvm-svn: 159904
2012-07-07 22:48:24 +00:00
Richard Smith b063d93cfb Remove typedef which is unused after r159189.
llvm-svn: 159224
2012-06-26 20:54:26 +00:00
Richard Smith 26d4cc1b96 Fix lifetime issue for backing APValue of OpaqueValueExpr in recursive
constexpr function evaluation, and corresponding ASan / valgrind issue in
tests, by storing the corresponding value with the relevant stack frame. This
also prevents re-evaluation of the source of the underlying OpaqueValueExpr,
which makes a major performance difference for certain contrived code (see
testcase update).

llvm-svn: 159189
2012-06-26 08:12:11 +00:00
Eli Friedman 4830ec8260 Use std::map instead of llvm::DenseMap because we rely on the stability of references to values in these maps. PR13197.
llvm-svn: 159161
2012-06-25 21:21:08 +00:00
David Blaikie 40ed29730b Revert Decl's iterators back to pointer value_type rather than reference value_type
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.

This rolls back r155808 and r155869.

Review by Doug Gregor incorporating feedback from Chandler Carruth.

llvm-svn: 158104
2012-06-06 20:45:41 +00:00
Richard Smith 01ade177e9 If the first argument of __builtin_object_size can be folded to a constant
pointer, but such folding encounters side-effects, ignore the side-effects
rather than performing them at runtime: CodeGen generates wrong code for
__builtin_object_size in that case.

llvm-svn: 157310
2012-05-23 04:13:20 +00:00
John McCall d7bca7629c My first effort to do this more subtly failed, so elaborately
test for an invalid declaration at every single place in the
constant evaluator that's about to request a struct layout.

llvm-svn: 155868
2012-05-01 00:38:49 +00:00
David Blaikie 2d7c57ec1d Remove the ref/value inconsistency in filter_decl_iterator.
filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.

This change errs on the side of value, making op-> return T* and op* return
T&.

(reviewed by Richard Smith)

llvm-svn: 155808
2012-04-30 02:36:29 +00:00
John McCall 3c79d88f06 Fix a crash-on-invalid where the constant evaluator would try to
evaluate certain expressions involving invalidly-defined classes.

llvm-svn: 155645
2012-04-26 18:10:01 +00:00
Patrick Beard 0caa39474b Implements boxed expressions for Objective-C. <rdar://problem/10194391>
llvm-svn: 155082
2012-04-19 00:25:12 +00:00
Eli Friedman 2f5b7c542e Per Richard's comments on r154794, add the checks necessary to handle constant-folding relational comparisons safely in case the user is using -fwrapv or equivalent.
llvm-svn: 154849
2012-04-16 19:23:57 +00:00
Eli Friedman 6c31cb4d8d Make constant evaluation for pointer comparisons work correctly for some uncommon cases. <rdar://problem/10962435>.
llvm-svn: 154794
2012-04-16 04:30:08 +00:00
Francois Pichet 0066db9039 The result of the Microsoft __uuidof operator must be considered a global lvalue during constant expression evaluation.
Otherwise we would get this error in C++11 mode (because of a recent change):
   error: non-type template argument of type 'const _GUID *' is not a constant expression

For code like:
template <const GUID* g = &__uuidof(struct_with_uuid)>
class COM_CLASS { };

llvm-svn: 154790
2012-04-16 04:08:35 +00:00
Richard Smith 9ec1e48b59 PR12226: don't generate wrong code if a braced string literal is used to
initialize an array of unsigned char. Outside C++11 mode, this bug was benign,
and just resulted in us emitting a constant which was double the required
length, padded with 0s. In C++11, it resulted in us generating an array whose
first element was something like  i8 ptrtoint ([n x i8]* @str to i8).

llvm-svn: 154756
2012-04-15 02:50:59 +00:00
Richard Smith 01ba47d7b6 Implement the missing pieces needed to support libstdc++4.7's <atomic>:
__atomic_test_and_set, __atomic_clear, plus a pile of undocumented __GCC_*
predefined macros.

Implement library fallback for __atomic_is_lock_free and
__c11_atomic_is_lock_free, and implement __atomic_always_lock_free.

Contrary to their documentation, GCC's __atomic_fetch_add family don't
multiply the operand by sizeof(T) when operating on a pointer type.
libstdc++ relies on this quirk. Remove this handling for all but the
__c11_atomic_fetch_add and __c11_atomic_fetch_sub builtins.

Contrary to their documentation, __atomic_test_and_set and __atomic_clear
take a first argument of type 'volatile void *', not 'void *' or 'bool *',
and __atomic_is_lock_free and __atomic_always_lock_free have an argument
of type 'const volatile void *', not 'void *'.

With this change, libstdc++4.7's <atomic> passes libc++'s atomic test suite,
except for a couple of libstdc++ bugs and some cases where libc++'s test
suite tests for properties which implementations have latitude to vary.

llvm-svn: 154640
2012-04-13 00:45:38 +00:00
Richard Smith b1e36c662b Provide, and document, a set of __c11_atomic_* intrinsics to implement C11's
<stdatomic.h> header.

In passing, fix LanguageExtensions to note that C11 and C++11 are no longer
"upcoming standards" but are now actually standardized.

llvm-svn: 154513
2012-04-11 17:55:32 +00:00
Richard Smith 4051ff7650 Don't forget to evaluate the subexpression in a null pointer cast. If we're
converting from std::nullptr_t, the subexpression might have side-effects.

llvm-svn: 154278
2012-04-08 08:02:07 +00:00
Douglas Gregor 31f55dced5 Implement support for null non-type template arguments for non-type
template parameters of pointer, pointer-to-member, or nullptr_t
type in C++11. Fixes PR9700 / <rdar://problem/11193097>.

llvm-svn: 154219
2012-04-06 22:40:38 +00:00
Argyrios Kyrtzidis 5957b7042a Simplify DataRecursiveIntBinOpEvaluator::VisitBinOp() a bit and make sure we don't
evaluate RHS if LHS could not be evaluated and keepEvaluatingAfterFailure() is false.

llvm-svn: 153235
2012-03-22 02:13:06 +00:00
Richard Trieu ba4d0871f7 Change the binary operator data recursive evaluator to not stop at the first
non-constant value encountered.  This allows the evaluator to deduce that
expressions like (x < 5 || true) is equal to true.  Previously, it would visit
x and determined that the entire expression is could not evaluated to a
constant.

This fixes PR12318.

llvm-svn: 153226
2012-03-21 23:30:30 +00:00
Argyrios Kyrtzidis 57595e46fd [Sema] Introduce a data recursive evaluator specific to binary operators.
This allows us to handle extreme cases of chained binary operators without causing stack
overflow.
The binary operators that are handled with the data recursive evaluator are
comma, logical, or operators that have operands with integral or enumeration type.

Part of rdar://10941790.

llvm-svn: 152819
2012-03-15 18:07:16 +00:00
Argyrios Kyrtzidis 94d428bb81 Remove hacky temporary fix of r151585.
llvm-svn: 152818
2012-03-15 18:07:13 +00:00
Richard Smith ce1ec5e1f5 Unrevert r152761 (reverted in r152772) with a fix for the issue which was
breaking bootstrap. No test yet: it's quite hard to tickle the failure case.
The specific testcase for this wouldn't be useful for testing anything more
general than a reintroduction of this precise bug in any case.

llvm-svn: 152775
2012-03-15 04:53:45 +00:00
Daniel Dunbar dee601905a Revert r152761 "Minor optimization to constant evaluation: don't bother
computing expr source...", it breaks bootstrap.

llvm-svn: 152772
2012-03-15 03:04:21 +00:00
Richard Smith 79aa513231 Minor optimization to constant evaluation: don't bother computing expr source
locations for diagnostics we're not going to emit, and don't track the subobject
designator outside C++11 (since we're not going to use it anyway).

This seems to give about a 0.5% speedup on 403.gcc/combine.c, but the results
were sufficiently noisy that I can't reject the null hypothesis.

llvm-svn: 152761
2012-03-15 00:41:48 +00:00
Richard Smith ac2f0b1f91 Allow vectors to be constructed from constexpr function arguments in
constant expressions.

llvm-svn: 152665
2012-03-13 20:58:32 +00:00
David Blaikie bbafb8a745 Unify naming of LangOptions variable/get function across the Clang stack (Lex to AST).
The member variable is always "LangOpts" and the member function is always "getLangOpts".

Reviewed by Chris Lattner

llvm-svn: 152536
2012-03-11 07:00:24 +00:00
Douglas Gregor f31cee6e1d Add a missing 'template' keyword.
llvm-svn: 152526
2012-03-11 02:23:56 +00:00
John McCall 113bee0536 Remove BlockDeclRefExpr and introduce a bit on DeclRefExpr to
track whether the referenced declaration comes from an enclosing
local context.  I'm amenable to suggestions about the exact meaning
of this bit.

llvm-svn: 152491
2012-03-10 09:33:50 +00:00
Richard Smith 4e9e523fcf Assign APValues by swapping from a temporary. Removes a bunch of unnecessary
copy-construction, which Daniel Dunbar reports as giving a 0.75% speedup on
403.gcc/combine.c. The performance differences on my constexpr torture tests
are below the noise floor.

llvm-svn: 152455
2012-03-10 00:28:11 +00:00
Daniel Dunbar 9d35581907 [AST] Reduce Decl::getASTContext() calls.
- This function is not at all free; pass it around along some hot paths instead
   of recomputing it deep inside various VarDecl methods.

llvm-svn: 152363
2012-03-09 01:51:51 +00:00
Richard Smith c67fdd4eb9 AST representation for user-defined literals, plus just enough of semantic
analysis to make the AST representation testable. They are represented by a
new UserDefinedLiteral AST node, which is a sugared CallExpr. All semantic
properties, including full CodeGen support, are achieved for free by this
representation.

UserDefinedLiterals can never be dependent, so no custom instantiation
behavior is required. They are mangled as if they were direct calls to the
underlying literal operator. This matches g++'s apparent behavior (but not its
actual mangling, which is broken for literal-operator-ids).

User-defined *string* literals are now fully-operational, but the semantic
analysis is quite hacky and needs more work. No other forms of user-defined
literal are created yet, but the AST support for them is present.

This patch committed after midnight because we had already hit the quota for
new kinds of literal yesterday.

llvm-svn: 152211
2012-03-07 08:35:16 +00:00
Richard Smith ecc124733a The constant folder's diagnosic mechanism is irrelevant for C; don't bother
producing a C-only diagnostic.

llvm-svn: 152181
2012-03-07 00:30:44 +00:00
Ted Kremenek e65b086e07 Add clang support for new Objective-C literal syntax for NSDictionary, NSArray,
NSNumber, and boolean literals.  This includes both Sema and Codegen support.
Included is also support for new Objective-C container subscripting.

My apologies for the large patch.  It was very difficult to break apart.
The patch introduces changes to the driver as well to cause clang to link
in additional runtime support when needed to support the new language features.

Docs are forthcoming to document the implementation and behavior of these features.

llvm-svn: 152137
2012-03-06 20:05:56 +00:00
Richard Smith 2e312c8738 constexpr: Remove APValue/CCValue distinction. It is no longer useful given the
resolution of core issue 1454.

llvm-svn: 151991
2012-03-03 22:46:17 +00:00
Argyrios Kyrtzidis 981a961d03 Move llvm/ADT/SaveAndRestore.h -> llvm/Support/SaveAndRestore.h.
Needs llvm update.

llvm-svn: 151829
2012-03-01 19:45:56 +00:00
Argyrios Kyrtzidis 465e137558 When evaluating integer expressions include a check for sub-expressions
depth and error if we exceed a max value, to make sure we avoid a stack overflow.

This is a hacky temporary fix. rdar://10913206.

llvm-svn: 151585
2012-02-27 23:18:37 +00:00
Argyrios Kyrtzidis 91d0098dc8 Revert testing code I committed by mistake in r151464.
llvm-svn: 151548
2012-02-27 20:21:34 +00:00
Argyrios Kyrtzidis 8d4677ad26 Revert r151460 as it is not enough to address the issue.
Original log:
When evaluating integer expressions handle logical operators outside
VisitBinaryOperator() to reduce stack pressure for source with huge number
of logical operators.

Fixes rdar://10913206.

llvm-svn: 151464
2012-02-25 23:21:37 +00:00
Argyrios Kyrtzidis 70f9eb571e When evaluating integer expressions handle logical operators outside
VisitBinaryOperator() to reduce stack pressure for source with huge number
of logical operators.

Fixes rdar://10913206.

llvm-svn: 151460
2012-02-25 21:38:16 +00:00
Richard Smith 6365c9138e When checking whether a reference to a variable is an ICE, look at the type of
the declaration, not at the type of the DeclRefExpr, since within a lambda the
DeclRefExpr can be more const than the declaration is.

llvm-svn: 151399
2012-02-24 22:12:32 +00:00
Douglas Gregor 093d4be550 Remove some trivial uses of hasTrivialCopyConstructor() and
hasTrivialMoveConstructor().

llvm-svn: 151354
2012-02-24 07:55:51 +00:00
Douglas Gregor 29c42f2a25 Implement a new type trait __is_trivially_constructible(T, Args...)
that provides the behavior of the C++11 library trait
std::is_trivially_constructible<T, Args...>, which can't be
implemented purely as a library.

Since __is_trivially_constructible can have zero or more arguments, I
needed to add Yet Another Type Trait Expression Class, this one
handling arbitrary arguments. The next step will be to migrate
UnaryTypeTrait and BinaryTypeTrait over to this new, more general
TypeTrait class.

Fixes the Clang side of <rdar://problem/10895483> / PR12038.

llvm-svn: 151352
2012-02-24 07:38:34 +00:00
Douglas Gregor ed90df3800 Generate an AST for the conversion from a lambda closure type to a
block pointer that returns a block literal which captures (by copy)
the lambda closure itself. Some aspects of the block literal are left
unspecified, namely the capture variable (which doesn't actually
exist) and the body (which will be filled in by IRgen because it can't
be written as an AST).

Because we're switching to this model, this patch also eliminates
tracking the copy-initialization expression for the block capture of
the conversion function, since that information is now embedded in the
synthesized block literal. -1 side tables FTW.

llvm-svn: 151131
2012-02-22 05:02:47 +00:00
Eli Friedman ebea9aff0d Fix a crash in the diangostic code in EvalConstant. PR12043.
llvm-svn: 151100
2012-02-21 22:41:33 +00:00
Sebastian Redl e6c32e6293 Refuse to compile global std::initializer_lists instead of doing completely the wrong thing.
llvm-svn: 150928
2012-02-19 14:53:49 +00:00
Richard Smith 66c9699ac3 Implement constant expression support for __real__ and __imag__ on lvalue
complex numbers. Treat complex numbers as arrays of the corresponding component
type, in order to make std::complex behave properly if implemented in terms of
_Complex T.

Apparently libstdc++'s std::complex is implemented this way, and we were
rejecting a member like this:

  constexpr double real() { return __real__ val; }

because it was marked constexpr but unable to produce a constant expression.

llvm-svn: 150895
2012-02-18 22:04:06 +00:00
Richard Smith 0dea49e324 Fix a problem in the GCC testsuite, exposed by r150557. Compound literals
are represented as prvalues in C++; don't be fooled into thinking they're
global lvalues.

llvm-svn: 150870
2012-02-18 04:58:18 +00:00
Richard Smith 14a941380a Make sure all remaining parts of the constant evaluator are aware that an array
can be represented by an LValue, and use that to simplify the code a little.

llvm-svn: 150789
2012-02-17 03:35:37 +00:00
Richard Smith 5d108606cc PR12012: Fix a regression in r150419 where we would try (and fail) to
zero-initialize class types with virtual bases when constant-evaluating an
initializer.

llvm-svn: 150770
2012-02-17 00:44:16 +00:00
Richard Smith 17100bad0a constexpr tidyups:
* Fix bug when determining whether && / || are potential constant expressions
  * Try harder when determining whether ?: is a potential constant expression
  * Produce a diagnostic on sizeof(VLA) to provide a better source location

llvm-svn: 150657
2012-02-16 02:46:34 +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
John McCall c62bb39142 Split reinterpret_casts of member pointers out from CK_BitCast; this
is general goodness because representations of member pointers are
not always equivalent across member pointer types on all ABIs
(even though this isn't really standard-endorsed).

Take advantage of the new information to teach IR-generation how
to do these reinterprets in constant initializers.  Make sure this
works when intermingled with hierarchy conversions (although
this is not part of our motivating use case).  Doing this in the
constant-evaluator would probably have been better, but that would
require a *lot* of extra structure in the representation of
constant member pointers:  you'd really have to track an arbitrary
chain of hierarchy conversions and reinterpretations in order to
get this right.  Ultimately, this seems less complex.  I also
wasn't quite sure how to extend the constant evaluator to handle
foldings that we don't actually want to treat as extended
constant expressions.

llvm-svn: 150551
2012-02-15 01:22:51 +00:00
Richard Smith ab44d9b321 constexpr: evaluation support for nullptr comparisons.
llvm-svn: 150521
2012-02-14 22:35:28 +00:00
Richard Smith 98a0a49fbf Pending clear answer from WG21 on whether core issue 903 is intended to apply to
C++11 or just C++17, restrict the set of null pointer constants in C++11 mode
back to those which were considered null in C++98.

llvm-svn: 150510
2012-02-14 21:38:30 +00:00
Richard Smith 6331c408b5 Deal with a horrible C++11 special case. If a non-literal type has a constexpr
constructor, and that constructor is used to initialize an object of static
storage duration such that all members and bases are initialized by constant
expressions, constant initialization is performed. In this case, the object
can still have a non-trivial destructor, and if it does, we must emit a dynamic
initializer which performs no initialization and instead simply registers that
destructor.

llvm-svn: 150419
2012-02-13 22:16:19 +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 5a294e6a2c CWG issue 1405: mutable members are allowed in literal types, but can't undergo
lvalue-to-rvalue conversions in constant expressions.

llvm-svn: 150145
2012-02-09 03:29:58 +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 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
Benjamin Kramer 7ec12c928a Revert my patches which removed Diagnostic.h includes by moving some operator overloads out of line.
This seems to negatively affect compile time onsome ObjC tests
(which use a lot of partial diagnostics I assume). I have to come
up with a way to keep them inline without including Diagnostic.h
everywhere. Now adding a new diagnostic requires a full rebuild
of e.g. the static analyzer which doesn't even use those diagnostics.

This reverts commit 6496bd10dc3a6d5e3266348f08b6e35f8184bc99.
This reverts commit 7af19b817ba964ac560b50c1ed6183235f699789.
This reverts commit fdd15602a42bbe26185978ef1e17019f6d969aa7.
This reverts commit 00bd44d5677783527d7517c1ffe45e4d75a0f56f.
This reverts commit ef9b60ffed980864a8db26ad30344be429e58ff5.

llvm-svn: 150006
2012-02-07 22:29:24 +00:00
Douglas Gregor e31e606ff3 Introduce basic ASTs for lambda expressions. This covers:
- Capturing variables by-reference and by-copy within a lambda
  - The representation of lambda captures
  - The creation of the non-static data members in the lambda class
  that store the captured variables
  - The initialization of the non-static data members from the
  captured variables
  - Pretty-printing lambda expressions

There are a number of FIXMEs, both explicit and implied, including:
  - Creating a field for a capture of 'this'
  - Improved diagnostics for initialization failures when capturing
  variables by copy
  - Dealing with temporaries created during said initialization
  - Template instantiation
  - AST (de-)serialization
  - Binding and returning the lambda expression; turning it into a
  proper temporary
  - Lots and lots of semantic constraints
  - Parameter pack captures

llvm-svn: 149977
2012-02-07 10:09:13 +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
Benjamin Kramer 3307c508c9 Move various diagnostic operator<< overloads out of line and remove includes of Diagnostic.h.
Fix all the files that depended on transitive includes of Diagnostic.h.
With this patch in place changing a diagnostic no longer requires a full rebuild of the StaticAnalyzer.

llvm-svn: 149781
2012-02-04 12:31:12 +00:00
Richard Smith 74388b4ec0 constexpr:
The recent support for potential constant expressions exposed a bug in the
  implementation of libstdc++4.6, where numeric_limits<int>::min() is defined
  as (int)1 << 31, which isn't a constant expression. Disable the 'constexpr
  function never produces a constant expression' error inside system headers
  to compensate.

llvm-svn: 149729
2012-02-04 00:33:54 +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