Commit Graph

799 Commits

Author SHA1 Message Date
Richard Smith
3a8244df6f Implement P0482R2, support for char8_t type.
This is not yet part of any C++ working draft, and so is controlled by the flag
-fchar8_t rather than a -std= flag. (The GCC implementation is controlled by a
flag with the same name.)

This implementation is experimental, and will be removed or revised
substantially to match the proposal as it makes its way through the C++
committee.

llvm-svn: 331244
2018-05-01 05:02:45 +00:00
Benjamin Kramer
33b7092601 [AST] strcmp/memcmp always compares unsigned chars.
This makes it return the right result in a couple of edge cases. The
wide versions always do the comparison on the underlying wchar_t type.

llvm-svn: 330656
2018-04-23 22:04:34 +00:00
Malcolm Parsons
fab3680990 Clean carriage returns from lib/ and include/. NFC.
Summary:
Clean carriage returns from lib/ and include/. NFC.
(I have to make this change locally in order for `git diff` to show sane output after I edit a file, so I might as well ask for it to be committed. I don't have commit privs myself.)
(Without this patch, `git rebase`ing any change involving SemaDeclCXX.cpp is a real nightmare. :( So while I have no right to ask for this to be committed, geez would it make my workflow easier if it were.)

Here's the command I used to reformat things. (Requires bash and OSX/FreeBSD sed.)

    git grep -l $'\r' lib include | xargs sed -i -e $'s/\r//'
    find lib include -name '*-e' -delete

Reviewers: malcolm.parsons

Reviewed By: malcolm.parsons

Subscribers: emaste, krytarowski, cfe-commits

Differential Revision: https://reviews.llvm.org/D45591

Patch by Arthur O'Dwyer.

llvm-svn: 330112
2018-04-16 08:31:08 +00:00
Akira Hatanaka
4e2698ca9e [ExprConstant] Use an AST node and a version number as a key to create
an APValue and retrieve it from map Temporaries.

The version number is needed when a single AST node is visited multiple
times and is used to create APValues that are required to be distinct
from each other (for example, MaterializeTemporaryExprs in default
arguments and VarDecls in loops).

rdar://problem/36505742

Differential Revision: https://reviews.llvm.org/D42776

llvm-svn: 329671
2018-04-10 05:15:01 +00:00
Manoj Gupta
4b3eefa5e8 Disable -fmerge-all-constants as default.
Summary:
"-fmerge-all-constants" is a non-conforming optimization and should not
be the default. It is also causing miscompiles when building Linux
Kernel (https://lkml.org/lkml/2018/3/20/872).

Fixes PR18538.

Reviewers: rjmccall, rsmith, chandlerc

Reviewed By: rsmith, chandlerc

Subscribers: srhines, cfe-commits

Differential Revision: https://reviews.llvm.org/D45289

llvm-svn: 329300
2018-04-05 15:29:52 +00:00
Erik Pilkington
11232912b1 [AST] Don't track lambda captures when checking a potential constant expression.
Fixes PR36054.

Differential revision: https://reviews.llvm.org/D45194

llvm-svn: 329244
2018-04-05 00:12:05 +00:00
Joel E. Denny
8150810556 Reland "[Attr] Fix parameter indexing for several attributes"
Relands r326602 (reverted in r326862) with new test and fix for
PR36620.

Differential Revision: https://reviews.llvm.org/D43248

llvm-svn: 327405
2018-03-13 14:51:22 +00:00
Richard Smith
69cf59ed26 PR36645: Go looking for an appropriate array bound when constant-evaluating a
name of an array object.

llvm-svn: 327099
2018-03-09 02:00:01 +00:00
George Burgess IV
4763876f4b Reland r326766 (with a slightly modified test)
The original revert was done in r326869, since reverting r326602 broke
the test added by this.

The new test should be less dependent on r326602.

llvm-svn: 326872
2018-03-07 04:52:34 +00:00
Nico Weber
b2ecd46ae4 Revert 326766 too, after r326862 the test fails and I don't know how to fix.
llvm-svn: 326869
2018-03-07 03:00:25 +00:00
Nico Weber
bbf648253d Revert r326602, it caused PR36620.
llvm-svn: 326862
2018-03-07 02:22:41 +00:00
George Burgess IV
9753b7903d [ExprConstant] Look through ExprWithCleanups for allocsize
llvm-svn: 326766
2018-03-06 07:42:36 +00:00
Joel E. Denny
4925445958 [Attr] Fix parameter indexing for several attributes
The patch fixes a number of bugs related to parameter indexing in
attributes:

* Parameter indices in some attributes (argument_with_type_tag,
  pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
  and ownership_returns) are specified in source as one-origin
  including any C++ implicit this parameter, were stored as
  zero-origin excluding any this parameter, and were erroneously
  printing (-ast-print) and confusingly dumping (-ast-dump) as the
  stored values.

* For alloc_size, the C++ implicit this parameter was not subtracted
  correctly in Sema, leading to assert failures or to silent failures
  of __builtin_object_size to compute a value.

* For argument_with_type_tag, pointer_with_type_tag, and
  ownership_returns, the C++ implicit this parameter was not added
  back to parameter indices in some diagnostics.

This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes.  ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed.  Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*].  This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument.  The only exception is xray_log_args's
argument, which is encoded as a count not an index.

Differential Revision: https://reviews.llvm.org/D43248

llvm-svn: 326602
2018-03-02 19:03:22 +00:00
George Burgess IV
00f70bd933 Remove redundant casts. NFC
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.

Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).

I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.

llvm-svn: 326416
2018-03-01 05:43:23 +00:00
Volodymyr Sapsai
e8f1ffb50a [ExprConstant] Fix crash when initialize an indirect field with another field.
When indirect field is initialized with another field, you have
MemberExpr with CXXThisExpr that corresponds to the field's immediate
anonymous parent. But 'this' was referring to the non-anonymous parent.
So when we were building LValue Designator, it was incorrect as it had
wrong starting point. Usage of such designator would cause unexpected
APValue changes and crashes.

The fix is in adjusting 'this' for indirect fields from non-anonymous
parent to the field's immediate parent.

Discovered by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4985

rdar://problem/36359187

Reviewers: rsmith, efriedma

Reviewed By: rsmith

Subscribers: cfe-commits, jkorous-apple

Differential Revision: https://reviews.llvm.org/D42498

llvm-svn: 325997
2018-02-23 23:59:20 +00:00
Richard Smith
9defb7d6b1 In C++14 onwards, it is permitted to read mutable members in constant
expressions, if their lifetime began during the evaluation of the expression.

This is technically not allowed in C++11, though we could consider permitting
it there too, as an extension.

llvm-svn: 325663
2018-02-21 03:38:30 +00:00
Ivan A. Kosarev
01df519f7e [AST] Refine the condition for element-dependent array fillers
This patch fixes clang to not consider braced initializers for
aggregate elements of arrays to be potentially dependent on the
indices of the initialized elements. Resolves bug 18978:
initialize a large static array = clang oom?
https://bugs.llvm.org/show_bug.cgi?id=18978

Differential Revision: https://reviews.llvm.org/D43187

llvm-svn: 325120
2018-02-14 13:10:35 +00:00
Aaron Ballman
a503855906 Track in the AST whether the operand to a UnaryOperator can overflow and then use that logic when evaluating constant expressions and emitting codegen.
llvm-svn: 322074
2018-01-09 13:07:03 +00:00
Benjamin Kramer
dfecbe9ad8 Add support for a limited subset of TS 18661-3 math builtins.
These just overloads for _Float128. They're supported by GCC 7 and used
by glibc. APFloat support is already there so just add the overloads.

__builtin_copysignf128
__builtin_fabsf128
__builtin_huge_valf128
__builtin_inff128
__builtin_nanf128
__builtin_nansf128

This is the same support that GCC has, according to the documentation,
but limited to _Float128.

llvm-svn: 321948
2018-01-06 21:49:54 +00:00
Alex Lorenz
4e246485a8 Fix an assertion failure regression in isDesignatorAtObjectEnd for
__builtin_object_size with incomplete array type in struct

The commit r316245 introduced a regression that causes an assertion failure when
Clang tries to cast an IncompleteArrayType to a PointerType when evaluating
__builtin_object_size.

rdar://36094951

Differential Revision: https://reviews.llvm.org/D41405

llvm-svn: 321222
2017-12-20 21:03:38 +00:00
Adrian Prantl
f3b3ccda59 Silence a bunch of implicit fallthrough warnings
llvm-svn: 321115
2017-12-19 22:06:11 +00:00
Richard Smith
c70f1d63f8 [c++20] P0515R3: Parsing support and basic AST construction for operator <=>.
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.

All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.

llvm-svn: 320707
2017-12-14 15:16:18 +00:00
Richard Smith
efdb50375f PR35214: don't crash if we see an array of unknown bound added to an empty but invalid designator.
llvm-svn: 318258
2017-11-15 03:03:56 +00:00
Jordan Rose
d4503da40c Unnamed bitfields don't block constant evaluation of constexpr ctors
C++14 [dcl.constexpr]p4 states that in the body of a constexpr
constructor,

> every non-variant non-static data member and base class sub-object
  shall be initialized

However, [class.bit]p2 notes that

> Unnamed bit-fields are not members and cannot be initialized.

Therefore, we should make sure to filter them out of the check that
all fields are initialized.

Fixing this makes the constant evaluator a bit smarter, and
specifically allows constexpr constructors to avoid tripping
-Wglobal-constructors when the type contains unnamed bitfields.

Reviewed at https://reviews.llvm.org/D39035.

llvm-svn: 316408
2017-10-24 02:17:07 +00:00
Richard Smith
6f4f0f1865 Implement current CWG direction for support of arrays of unknown bounds in
constant expressions.

We permit array-to-pointer decay on such arrays, but disallow pointer
arithmetic (since we do not know whether it will have defined behavior).

This is based on r311970 and r301822 (the former by me and the latter by Robert
Haberlach). Between then and now, two things have changed: we have committee
feedback indicating that this is indeed the right direction, and the code
broken by this change has been fixed.

This is necessary in C++17 to continue accepting certain forms of non-type
template argument involving arrays of unknown bound.

llvm-svn: 316245
2017-10-20 22:56:25 +00:00
Jonas Hahnfeld
23604a8399 [OpenMP] Implement omp_is_initial_device() as builtin
This allows to return the static value that we know at compile time.

Differential Revision: https://reviews.llvm.org/D38968

llvm-svn: 316001
2017-10-17 14:28:14 +00:00
Erik Pilkington
4292549fb4 [ExprConstant] Allow constexpr ctor to modify non static data members
Fixes PR19741.

Differential revision: https://reviews.llvm.org/D38483

llvm-svn: 314865
2017-10-04 00:18:55 +00:00
Martin Bohme
542c84b2a1 Revert "Improve constant expression evaluation of arrays of unknown bound."
This reverts commit r311970.

Breaks internal tests.

llvm-svn: 312108
2017-08-30 10:44:46 +00:00
Richard Smith
2cd5604823 Improve constant expression evaluation of arrays of unknown bound.
The standard is not clear on how these are supposed to be handled, so we
conservatively treat as non-constant any cases whose value is unknown or whose
evaluation might result in undefined behavior.

llvm-svn: 311970
2017-08-29 01:52:13 +00:00
Richard Smith
7cd577bb0d PR34161: support evaluation of 'void()' expressions in C++14 onwards.
llvm-svn: 311115
2017-08-17 19:35:50 +00:00
Daniel Jasper
a7e061f07b Fix undefined behavior that is caused by not always initializing a bool.
The fix in r310994 is incomplete, as moveFromAndCancel can set the
pointer without initializing OldIsSpeculativelyEvaluating.

llvm-svn: 311070
2017-08-17 06:33:46 +00:00
Chandler Carruth
bacb80d0d9 Fix a UBSan failure where this boolean was copied when uninitialized.
When r310905 moved the pointer and bool out of a PointerIntPair, it made
them end up uninitialized and caused UBSan failures when copying the
uninitialized boolean. However, making the pointer be null should avoid
the reference to the boolean entirely.

llvm-svn: 310994
2017-08-16 07:22:49 +00:00
Reid Kleckner
fdb3df65b6 Avoid PointerIntPair of constexpr EvalInfo structs
They are stack allocated, so their alignment is not to be trusted.
32-bit MSVC only guarantees 4 byte stack alignment, even though alignof
would tell you otherwise. I tried fixing this with __declspec align, but
that apparently upsets GCC. Hopefully this version will satisfy all
compilers.

See PR32018 for some info about the mingw issues.

Should supercede https://reviews.llvm.org/D34873

llvm-svn: 310905
2017-08-15 01:17:47 +00:00
Reid Kleckner
cd016d8dc6 [MS] Don't statically initialize dllimport member function pointers
Summary:
r306137 made dllimport pointers to member functions non-constant. This
is correct because a load must be executed to resolve any dllimported
data. However, r306137 did not account for the use of dllimport member
function pointers used as template arguments.

This change re-lands r306137 with a template instantiation fix.

This fixes PR33570.

Reviewers: rnk, majnemer

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D34714

llvm-svn: 307446
2017-07-07 22:04:29 +00:00
Hiroshi Inoue
0c2734f8de fix trivial typos in comments; NFC
llvm-svn: 307123
2017-07-05 05:37:45 +00:00
Richard Smith
9f7df0c068 Revert r301742, which caused us to try to evaluate all full-expressions.
Also add testcases for a bunch of expression forms that cause our evaluator to
crash. See PR33140 and PR32864 for crashes that this was causing.

This reverts r305287, which reverted r305239, which reverted r301742. The
previous revert claimed that buildbots were broken, but did not add any
testcases and the buildbots have lost all memory of what was wrong here.

Changes to test/OpenMP are not reverted; another change has triggered those
tests to change their output in the same way that r301742 did.

llvm-svn: 306346
2017-06-26 23:19:32 +00:00
Reid Kleckner
33d501f7d1 Revert "[MS] Don't statically initialize dllimport member function pointers"
This reverts commit r306137. It has problems on code like this:

  struct __declspec(dllimport) Foo {
    int a;
    int get_a() { return a; }
  };
  template <int (Foo::*Getter)()> struct HasValue {
    int operator()(Foo *p) { return (p->*Getter)(); }
  };
  int main() {
    Foo f;
    f.a = 3;
    int x = HasValue<&Foo::get_a>()(&f);
  }

llvm-svn: 306175
2017-06-23 22:39:01 +00:00
Reid Kleckner
9c980cb502 [MS] Don't statically initialize dllimport member function pointers
We were already applying the same rules to dllimport function pointers.
David Majnemer added that logic back in r211677 to fix PR20130.  We
failed to extend that logic to non-virtual member function pointers,
which are basically function pointers in a struct with some extra
offsets.

Fixes PR33570.

llvm-svn: 306137
2017-06-23 18:29:13 +00:00
Diana Picus
bec724cbb0 Revert "Revert r301742 which made ExprConstant checking apply to all full-exprs."
This reverts commit r305239 because it broke the buildbots (the
diag-flags.cpp test is failing).

llvm-svn: 305287
2017-06-13 12:50:06 +00:00
Nick Lewycky
54992386f3 Revert r301742 which made ExprConstant checking apply to all full-exprs.
This patch also exposed pre-existing bugs in clang, see PR32864 and PR33140#c3 .

llvm-svn: 305239
2017-06-12 21:59:18 +00:00
Nick Lewycky
13073a6425 Revert r303316, a change to ExprConstant to evaluate function arguments.
The patch was itself correct but it uncovered other bugs which are going to be difficult to fix, per PR33140.

llvm-svn: 305233
2017-06-12 21:15:44 +00:00
Galina Kistanova
f87496d107 Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.
llvm-svn: 304650
2017-06-03 06:31:42 +00:00
Tim Northover
0150333a3c Create valid LValue to represent null pointers in constant exprs
We were leaving the SubobjectDesignator in a surprising situation, where
it was allegedly valid but didn't actually refer to a type. This caused
a crash later on.

This patch fills out the SubobjectDesignator with the pointee type (as
happens in other evaluations of constant pointers) so that we don't
crash later.

llvm-svn: 303957
2017-05-26 02:16:00 +00:00
Nick Lewycky
9add1594d2 The constant expression evaluator should examine function arguments for non-constexpr function calls unless the EvalInfo says to stop.
llvm-svn: 303317
2017-05-17 23:56:54 +00:00
Daniel Jasper
ffdee09350 Revert r301822 (and dependent r301825), which tried to improve the
handling of constexprs with unknown bounds.

This triggers a corner case of the language where it's not yet clear
whether this should be an error:

  struct A {
    static void *const a[];
    static void *const b[];
  };
  constexpr void *A::a[] = {&b[0]};
  constexpr void *A::b[] = {&a[0]};

When discovering the initializer for A::a, the bounds of A::b aren't known yet.
It is unclear whether warning about errors should be deferred until the end of
the translation unit, possibly resolving errors that can be resolved. In
practice, the compiler can know the bounds of all arrays in this example.

Credits for reproducers and explanation go to Richard Smith. Richard, please
add more info in case my explanation is wrong.

llvm-svn: 301963
2017-05-02 19:21:42 +00:00
Nick Lewycky
c190f96b7d Revert r301785 (and r301787) because they caused PR32864.
The fix is that ExprEvaluatorBase::VisitInitListExpr should handle transparent exprs instead of exprs with one element. Fixing that uncovers one testcase failure because the AST for "constexpr _Complex float test2 = {1};" is wrong (the _Complex prvalue should not be const-qualified), and a number of test failures in test/OpenMP where the captured stmt contains an InitListExpr that is in syntactic form.

llvm-svn: 301891
2017-05-02 01:06:16 +00:00
Benjamin Kramer
5699969912 Silence unused variable warning. NFC.
llvm-svn: 301825
2017-05-01 20:00:23 +00:00
Richard Smith
eec904f849 Improve handling of arrays of unknown bound in constant expressions.
Do not spuriously reject constexpr functions that access elements of an array
of unknown bound; this may later become valid once the bound is known. Permit
array-to-pointer decay on such arrays, but disallow pointer arithmetic (since
we do not know whether it will have defined behavior).

The standard is not clear on how this should work, but this seems to be a
decent answer.

Patch by Robert Haberlach!

llvm-svn: 301822
2017-05-01 18:49:04 +00:00
Nick Lewycky
499968f8a5 Handle expressions with non-literal types like ignored expressions if we are supposed to continue evaluating them.
Also fix a crash casting a derived nullptr to a virtual base.

llvm-svn: 301785
2017-05-01 02:03:23 +00:00
Nick Lewycky
e7d6fbdfb7 Remove Sema::CheckForIntOverflow, and instead check all full-expressions.
CheckForIntOverflow used to implement a whitelist of top-level expressions to
send to the constant expression evaluator, which handled many more expressions
than the CheckForIntOverflow whitelist did.

llvm-svn: 301742
2017-04-29 09:33:46 +00:00