Commit Graph

867 Commits

Author SHA1 Message Date
Fangrui Song 6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
Erich Keane 1ddd4bf87f Prevent Scoped Enums from being Integral constant expressions:
Discovered because of: https://bugs.llvm.org/show_bug.cgi?id=38235

It seems to me that a scoped enum should NOT be an integral constant expression
without a cast, so this seems like a sensical change.

Attributes that check for an integer parameter simply use this function to
ensure that they have an integer, so it was previously allowing a scoped enum.

Also added a test based on Richard's feedback to ensure that case labels still work.

Differential Revision: https://reviews.llvm.org/D49599

llvm-svn: 337585
2018-07-20 17:42:09 +00:00
Richard Smith 81dfef9202 PR38095: Allow constant-folding of loads through bitcasted pointers if
the bitcast only changed cvr-qualifications within the pointer type.

llvm-svn: 336746
2018-07-11 00:29:05 +00:00
Erich Keane cb54964f80 Fix __builtin_*_overflow when out-param isn't constexpr
As brought up on cfe-commits[1], r334650 causes the dependency of the
out parameter to the __builtin_*_overflow functions to be ignored. The result
was a usage that was otherwise constexpr (both operands to the operation were
constexpr) would be evaluated, but the out parameter wouldn't be modified, so
it would still be 'undef'.

This patch correctly handles the return value of handleAssignment to ensure that
this value is properly considered/evaluated.

[1] http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180702/233667.html

llvm-svn: 336364
2018-07-05 15:52:58 +00:00
Leonard Chan db01c3adc6 [Fixed Point Arithmetic] Fixed Point Precision Bits and Fixed Point Literals
This diff includes the logic for setting the precision bits for each primary fixed point type in the target info and logic for initializing a fixed point literal.

Fixed point literals are declared using the suffixes

```
hr: short _Fract
uhr: unsigned short _Fract
r: _Fract
ur: unsigned _Fract
lr: long _Fract
ulr: unsigned long _Fract
hk: short _Accum
uhk: unsigned short _Accum
k: _Accum
uk: unsigned _Accum
```
Errors are also thrown for illegal literal values

```
unsigned short _Accum u_short_accum = 256.0uhk;   // expected-error{{the integral part of this literal is too large for this unsigned _Accum type}}
```

Differential Revision: https://reviews.llvm.org/D46915

llvm-svn: 335148
2018-06-20 17:19:40 +00:00
Leonard Chan ab80f3c8b7 [Fixed Point Arithmetic] Addition of the remaining fixed point types and their saturated equivalents
This diff includes changes for the remaining _Fract and _Sat fixed point types.

```
signed short _Fract s_short_fract;
signed _Fract s_fract;
signed long _Fract s_long_fract;
unsigned short _Fract u_short_fract;
unsigned _Fract u_fract;
unsigned long _Fract u_long_fract;

// Aliased fixed point types
short _Accum short_accum;
_Accum accum;
long _Accum long_accum;
short _Fract short_fract;
_Fract fract;
long _Fract long_fract;

// Saturated fixed point types
_Sat signed short _Accum sat_s_short_accum;
_Sat signed _Accum sat_s_accum;
_Sat signed long _Accum sat_s_long_accum;
_Sat unsigned short _Accum sat_u_short_accum;
_Sat unsigned _Accum sat_u_accum;
_Sat unsigned long _Accum sat_u_long_accum;
_Sat signed short _Fract sat_s_short_fract;
_Sat signed _Fract sat_s_fract;
_Sat signed long _Fract sat_s_long_fract;
_Sat unsigned short _Fract sat_u_short_fract;
_Sat unsigned _Fract sat_u_fract;
_Sat unsigned long _Fract sat_u_long_fract;

// Aliased saturated fixed point types
_Sat short _Accum sat_short_accum;
_Sat _Accum sat_accum;
_Sat long _Accum sat_long_accum;
_Sat short _Fract sat_short_fract;
_Sat _Fract sat_fract;
_Sat long _Fract sat_long_fract;
```

This diff only allows for declaration of these fixed point types. Assignment and other operations done on fixed point types according to http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1169.pdf will be added in future patches.

Differential Revision: https://reviews.llvm.org/D46911

llvm-svn: 334718
2018-06-14 14:53:51 +00:00
Erich Keane 00958270aa Implement constexpr __builtin_*_overflow
As requested here:https://bugs.llvm.org/show_bug.cgi?id=37633
permit the __builtin_*_overflow builtins in constexpr functions.

Differential Revision: https://reviews.llvm.org/D48040

llvm-svn: 334650
2018-06-13 20:43:27 +00:00
Leonard Chan f921d85422 This diff includes changes for supporting the following types.
// Primary fixed point types
signed short _Accum s_short_accum;
signed _Accum s_accum;
signed long _Accum s_long_accum;
unsigned short _Accum u_short_accum;
unsigned _Accum u_accum;
unsigned long _Accum u_long_accum;

// Aliased fixed point types
short _Accum short_accum;
_Accum accum;
long _Accum long_accum;
This diff only allows for declaration of the fixed point types. Assignment and other operations done on fixed point types according to http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1169.pdf will be added in future patches. The saturated versions of these types and the equivalent _Fract types will also be added in future patches.

The tests included are for asserting that we can declare these types.

Fixed the test that was failing by not checking for dso_local on some
targets.

Differential Revision: https://reviews.llvm.org/D46084

llvm-svn: 333923
2018-06-04 16:07:52 +00:00
Leonard Chan 0d485dbb40 Revert "This diff includes changes for supporting the following types."
This reverts commit r333814, which fails for a test checking the bit
width on ubuntu.

llvm-svn: 333815
2018-06-02 03:27:13 +00:00
Leonard Chan db55d8331e This diff includes changes for supporting the following types.
```

// Primary fixed point types
signed short _Accum s_short_accum;
signed _Accum s_accum;
signed long _Accum s_long_accum;
unsigned short _Accum u_short_accum;
unsigned _Accum u_accum;
unsigned long _Accum u_long_accum;

// Aliased fixed point types
short _Accum short_accum;
_Accum accum;
long _Accum long_accum;

```

This diff only allows for declaration of the fixed point types. Assignment and other operations done on fixed point types according to http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1169.pdf will be added in future patches. The saturated versions of these types and the equivalent `_Fract` types will also be added in future patches.

The tests included are for asserting that we can declare these types.

Differential Revision: https://reviews.llvm.org/D46084

llvm-svn: 333814
2018-06-02 02:58:51 +00:00
Richard Smith 08b682bec1 Rework __builtin_classify_type support to better match GCC and to not assert on
unusual types.

Following the observed behavior of GCC, we now return -1 for vector types
(along with all of our extensions that GCC doesn't support), and for atomic
types we classify the underlying type.

GCC appears to have changed its classification for function and array arguments
between version 5 and version 6. Previously it would classify them as pointers
in C and as functions or arrays in C++, but from version 6 onwards, it
classifies them as pointers. We now follow the more recent GCC behavior rather
than emulating what I can only assume to be a historical bug in their C++
support for this builtin.

Finally, no version of GCC that I can find has ever used the "method"
classification for C++ pointers to member functions. Instead, GCC classifies
them as record types, presumably reflecting an internal implementation detail,
but whatever the reason we now produce compatible results.

llvm-svn: 333126
2018-05-23 21:18:00 +00:00
Richard Smith 3f1d6de4f7 Revert r332847; it caused us to miscompile certain forms of reference initialization.
llvm-svn: 332886
2018-05-21 20:36:58 +00:00
Serge Pavlov 9f8068420a [CodeGen] Recognize more cases of zero initialization
If a variable has an initializer, codegen tries to build its value. If
the variable is large in size, building its value requires substantial
resources. It causes strange behavior from user viewpoint: compilation
of huge zero initialized arrays like:

    char data_1[2147483648u] = { 0 };

consumes enormous amount of time and memory.

With this change codegen tries to determine if variable initializer is
equivalent to zero initializer. In this case variable value is not
constructed.

This change fixes PR18978.

Differential Revision: https://reviews.llvm.org/D46241

llvm-svn: 332847
2018-05-21 16:09:54 +00:00
Nicola Zaghen 3538b39ed5 [clang] Update uses of DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM

Explicitly avoided changing the strings in the clang-format tests.

Differential Revision: https://reviews.llvm.org/D44975

llvm-svn: 332350
2018-05-15 13:30:56 +00:00
Reid Kleckner 1a840d29b4 Allow dllimport non-type template arguments in C++17
Summary:
Fixes PR35772.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D43320

llvm-svn: 332018
2018-05-10 18:57:35 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Simon Pilgrim 3366dcfe1f Fix 'not all control paths return a value' MSVC warnings. NFCI.
llvm-svn: 331753
2018-05-08 09:40:32 +00:00
Eric Fiselier 0683c0e68d [C++2a] Implement operator<=> CodeGen and ExprConstant
Summary:
This patch tackles long hanging fruit for the builtin operator<=> expressions. It is currently needs some cleanup before landing, but I want to get some initial feedback.

The main changes are:

* Lookup, build, and store the required standard library types and expressions in `ASTContext`. By storing them in ASTContext we don't need to store (and duplicate) the required expressions in the BinaryOperator AST nodes. 

* Implement [expr.spaceship] checking, including diagnosing narrowing conversions. 

* Implement `ExprConstant` for builtin spaceship operators.

* Implement builitin operator<=> support in `CodeGenAgg`. Initially I emitted the required comparisons using `ScalarExprEmitter::VisitBinaryOperator`, but this caused the operand expressions to be emitted once for every required cmp.

* Implement [builtin.over] with modifications to support the intent of P0946R0. See the note on `BuiltinOperatorOverloadBuilder::addThreeWayArithmeticOverloads` for more information about the workaround.




Reviewers: rsmith, aaron.ballman, majnemer, rnk, compnerd, rjmccall

Reviewed By: rjmccall

Subscribers: rjmccall, rsmith, aaron.ballman, junbuml, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D45476

llvm-svn: 331677
2018-05-07 21:07:10 +00:00
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
Nick Lewycky 19ae6dc853 ObjCBoxedExpr can't be evaluated by the constant expression evaluator.
A boxed expression evaluates its subexpr and then calls an objc method to transform it into another value with pointer type. The objc method can never be constexpr and therefore this expression can never be evaluated. Fixes a miscompile boxing expressions with side-effects.

Also make ObjCBoxedExpr handling a normal part of the expression evaluator instead of being the only case besides full-expression where we check for integer overflow.

llvm-svn: 301721
2017-04-29 00:07:27 +00:00
Nick Lewycky ad8886896e In the expression evaluator, visit the index of an ArraySubscriptExpr even if we can't evaluate the base, if the evaluation mode tells us to continue evaluation.
llvm-svn: 301522
2017-04-27 07:27:36 +00:00
Nick Lewycky 20edee6a3e In the expression evaluator, descend into both the true and false expressions of a ConditionalOperator when the condition can't be evaluated and we're in an evaluation mode that says we should continue evaluating.
llvm-svn: 301520
2017-04-27 07:11:09 +00:00
Benjamin Kramer f6021ecddc Apply clang-tidy's performance-unnecessary-value-param to parts of clang.
No functionality change intended.

llvm-svn: 298443
2017-03-21 21:35:04 +00:00
Roger Ferrer Ibanez 3fa38a14ac Honor __unaligned in codegen for declarations and expressions
This patch honors the unaligned type qualifier (currently available through he
keyword __unaligned and -fms-extensions) in CodeGen. In the current form the
patch affects declarations and expressions. It does not affect fields of
classes.

Differential Revision: https://reviews.llvm.org/D30166

llvm-svn: 297276
2017-03-08 14:00:44 +00:00
Eric Fiselier 20f25cb6df [coroutines] Add DependentCoawaitExpr and fix re-building CoroutineBodyStmt.
Summary:
The changes contained in this patch are:

1. Defines a new AST node `CoawaitDependentExpr` for representing co_await expressions while the promise type is still dependent.
2. Correctly detect and transform the 'co_await' operand to  `p.await_transform(<expr>)`  when possible.
3. Change the initial/final suspend points to build during the initial parse, so they have the correct operator co_await lookup results.
4.  Fix transformation of the CoroutineBodyStmt so that it doesn't re-build the final/initial suspends.


@rsmith: This change is a little big, but it's not trivial for me to split it up. Please let me know if you would prefer this submitted as multiple patches.



Reviewers: rsmith, GorNishanov

Reviewed By: rsmith

Subscribers: ABataev, rsmith, mehdi_amini, cfe-commits

Differential Revision: https://reviews.llvm.org/D26057

llvm-svn: 297093
2017-03-06 23:38:15 +00:00
Richard Smith 64cb9ca456 PR32034: Evaluate _Atomic(T) in-place when T is a class or array type.
This is necessary in order for the evaluation of an _Atomic initializer for
those types to have an associated object, which an initializer for class or
array type needs.

llvm-svn: 295886
2017-02-22 22:09:50 +00:00
Benjamin Kramer aad1bdc863 Silence sign compare warning. NFC.
ExprConstant.cpp:6344:20: warning: comparison of integers of different
signs: 'const size_t' (aka 'const unsigned long') and 'typename
iterator_traits<Expr *const *>::difference_type' (aka 'long')
[-Wsign-compare]

llvm-svn: 295320
2017-02-16 14:08:41 +00:00
Anastasia Stulova 58984e7087 [OpenCL] Correct ndrange_t implementation
Removed ndrange_t as Clang builtin type and added
as a struct type in the OpenCL header.

Use type name to do the Sema checking in enqueue_kernel
and modify IR generation accordingly.

Review: D28058

Patch by Dmitry Borisenkov!  
 

llvm-svn: 295311
2017-02-16 12:27:47 +00:00
Faisal Vali 051e3a2b7d [cxx1z-constexpr-lambda] Implement captures - thus completing implementation of constexpr lambdas.
Enable evaluation of captures within constexpr lambdas by using a strategy similar to that used in CodeGen:
  - when starting evaluation of a lambda's call operator, create a map from VarDecl's to a closure's FieldDecls
  - every time a VarDecl (or '*this) that represents a capture is encountered while evaluating the expression via the expression evaluator (specifically the LValueEvaluator) in ExprConstant.cpp - it is replaced by the corresponding FieldDecl LValue (an Lvalue-to-Rvalue conversion on this LValue representation then determines the right rvalue when needed).

Thanks to Richard Smith and Hubert Tong for their review and feedback!

https://reviews.llvm.org/D29748

llvm-svn: 295279
2017-02-16 04:12:21 +00:00
George Burgess IV f9013bf8f0 Don't let EvaluationModes dictate whether an invalid base is OK
What we want to actually control this behavior is something more local
than an EvalutationMode. Please see the linked revision for more
discussion on why/etc.

This fixes PR31843.

Differential Revision: https://reviews.llvm.org/D29469

llvm-svn: 294800
2017-02-10 22:52:29 +00:00
George Burgess IV 5731707668 Fix typo. NFC
llvm-svn: 293871
2017-02-02 07:53:55 +00:00
Akira Hatanaka bc332648e8 Handle ObjCEncodeExpr in extractStringLiteralCharacter.
This fixes an assertion failure that occurs later in the function when
an ObjCEncodeExpr is cast to StringLiteral.

rdar://problem/30111207

llvm-svn: 293596
2017-01-31 02:31:39 +00:00
Richard Smith d6cc198d53 Improve fix for PR28739
Don't try to map an APSInt addend to an int64_t in pointer arithmetic before
bounds-checking it. This gives more consistent behavior (outside C++11, we
consistently use 2s complement semantics for both pointer and integer overflow
in constant expressions) and fixes some cases where in C++11 we would fail to
properly check for out-of-bounds pointer arithmetic (if the 2s complement
64-bit overflow landed us back in-bounds).

In passing, also fix some cases where we'd perform possibly-overflowing
arithmetic on CharUnits (which have a signed underlying type) during constant
expression evaluation.

llvm-svn: 293595
2017-01-31 02:23:02 +00:00
Richard Smith 642a2365fb PR28739: Check that integer values fit into 64 bits before extracting them as 64 bit values for pointer arithmetic.
This fixes various ways to tickle an assertion in constant expression
evaluation when using __int128. Longer term, we need to figure out what should
happen here: either any kind of overflow in offset calculation should result in
a non-constant value or we should truncate to 64 bits. In C++11 onwards, we're
effectively already checking for overflow because we strictly enforce array
bounds checks, but even there some forms of overflow can slip past undetected.

llvm-svn: 293568
2017-01-30 23:30:26 +00:00
Richard Smith 600b5261c4 PR0091R3: Implement parsing support for using templates as types.
This change adds a new type node, DeducedTemplateSpecializationType, to
represent a type template name that has been used as a type. This is modeled
around AutoType, and shares a common base class for representing a deduced
placeholder type.

We allow deduced class template types in a few more places than the standard
does: in conditions and for-range-declarators, and in new-type-ids. This is
consistent with GCC and with discussion on the core reflector. This patch
does not yet support deduced class template types being named in typename
specifiers.

llvm-svn: 293207
2017-01-26 20:40:47 +00:00
Richard Smith 5e29dd3fe0 P0426: Make the library implementation of constexpr char_traits a little easier
by providing a memchr builtin that returns char* instead of void*.

Also add a __has_feature flag to indicate the presence of constexpr forms of
the relevant <string> functions.

llvm-svn: 292555
2017-01-20 00:45:35 +00:00
David L. Jones f55ce36c02 Allow constexpr construction of subobjects unconditionally, not just in C++14.
Summary:
Per https://wg21.link/CWG1677, the C++11 standard did not clarify that constant
initialization of an object allowed constexpr brace-or-equal initialization of
subobjects:

  struct foo_t { union { int i; volatile int j; } u; };

  __attribute__((__require_constant_initialization__))
  static const foo_t x = {{0}};

Because foo_t::u has a volatile member, the initializer for x fails. However,
there is really no good reason, because this:

  union foo_u { int i; volatile int j; };
  __attribute__((__require_constant_initialization__))
  static const foo_u x = {0};

does have a constant initializer.

(This was triggered by musl's pthread_mutex_t type when building under C++11.)

Reviewers: rsmith

Subscribers: EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D28427

llvm-svn: 291480
2017-01-09 21:38:07 +00:00
George Burgess IV 177399e227 Add the diagnose_if attribute to clang.
`diagnose_if` can be used to have clang emit either warnings or errors
for function calls that meet user-specified conditions. For example:

```
constexpr int foo(int a)
  __attribute__((diagnose_if(a > 10, "configurations with a > 10 are "
                                      "expensive.", "warning")));

int f1 = foo(9);
int f2 = foo(10); // warning: configuration with a > 10 are expensive.
int f3 = foo(f2);
```

It currently only emits diagnostics in cases where the condition is
guaranteed to always be true. So, the following code will emit no
warnings:

```
constexpr int bar(int a) {
  foo(a);
  return 0;
}

constexpr int i = bar(10);
```

We hope to support optionally emitting diagnostics for cases like that
(and emitting runtime checks) in the future.

Release notes will appear shortly. :)

Differential Revision: https://reviews.llvm.org/D27424

llvm-svn: 291418
2017-01-09 04:12:14 +00:00
Faisal Vali c72a08c1f6 [cxx1z-constexpr-lambda] Implement constant evaluation of non-capturing lambda expressions.
Add a visitor for lambda expressions to RecordExprEvaluator in ExprConstant.cpp that creates an empty APValue of Struct type to represent the closure object. Additionally, add a LambdaExpr visitor to the TemporaryExprEvaluator that forwards constant evaluation of immediately-called-lambda-expressions to the one in RecordExprEvaluator through VisitConstructExpr.

This patch supports:
constexpr auto ID = [] (auto a) { return a; };
static_assert(ID(3.14) == 3.14);
static_assert([](auto a) { return a + 1; }(10) == 11);

Lambda captures are still not supported for constexpr lambdas.

llvm-svn: 291416
2017-01-09 03:02:53 +00:00
Faisal Vali d92e7499fb [cxx1z-constexpr-lambda] Make conversion function constexpr, and teach the expression-evaluator to evaluate the static-invoker.
This patch has been sitting in review hell since july 2016 and our lack of constexpr lambda support is getting embarrassing (given that I've had a branch that implements the feature (modulo *this capture) for over a year.  While in Issaquah I was enjoying shamelessly trying to convince folks of the lie that this was Richard's fault ;) I won't be able to do so in Kona since I won't be attending - so I'm going to aim to have this feature be implemented by then.

I'm quite confident of the approach in this patch, which simply maps the static-invoker 'thunk' back to the corresponding call-operator (specialization).

Thanks!

llvm-svn: 291397
2017-01-08 18:56:11 +00:00
George Burgess IV 7fb7e361bf Re-add objectsize function/incomplete type checks.
I accidentally omitted these when refactoring this code. This caused
problems when building parts of the test-suite on MacOS.

llvm-svn: 290916
2017-01-03 23:35:19 +00:00
George Burgess IV b531698ff0 Emit CCEDiags when evaluating a const variable.
This addresses post-review feedback from r290577.

llvm-svn: 290584
2016-12-27 05:33:20 +00:00
Egor Churaev 89831421af Fix problems in "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
Summary: Fixed warnings in commit: https://reviews.llvm.org/rL290171

Reviewers: djasper, Anastasia

Subscribers: yaxunl, cfe-commits, bader

Differential Revision: https://reviews.llvm.org/D27981

llvm-svn: 290431
2016-12-23 14:55:49 +00:00
George Burgess IV e37633713d Add the alloc_size attribute to clang, attempt 2.
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.

Fingers crossed that this patch sticks this time. :)

Original commit message:

This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
  number of bytes handed back to us by malloc/realloc/calloc/any user
  functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
  is OK sometimes. This is why we have a change in
  test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
  unrelated tests. Richard Smith okay'ed this idea some time ago in
  person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
  D26410. Lack of uniquing only really shows up as a problem when
  combined with our new eagerness in the face of const.

llvm-svn: 290297
2016-12-22 02:50:20 +00:00
Daniel Jasper 9068938eb0 Revert "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand."
This reverts commit r290171. It triggers a bunch of warnings, because
the new enumerator isn't handled in all switches. We want a warning-free
build.

Replied on the commit with more details.

llvm-svn: 290173
2016-12-20 10:05:04 +00:00
Egor Churaev 67c3f3ec68 [OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare operand.
Summary: Enabling the compression of CLK_NULL_QUEUE to variable of type queue_t.

Reviewers: Anastasia

Subscribers: cfe-commits, yaxunl, bader

Differential Revision: https://reviews.llvm.org/D27569

llvm-svn: 290171
2016-12-20 09:15:21 +00:00
Chandler Carruth d7738fe6ad Revert r290149: Add the alloc_size attribute to clang.
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.

George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.

llvm-svn: 290169
2016-12-20 08:28:19 +00:00
George Burgess IV a747027bc6 Add the alloc_size attribute to clang.
This patch does three things:

- Gives us the alloc_size attribute in clang, which lets us infer the
  number of bytes handed back to us by malloc/realloc/calloc/any user
  functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
  is OK sometimes. This is why we have a change in
  test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
  unrelated tests. Richard Smith okay'ed this idea some time ago in
  person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
  D26410. Lack of uniquing only really shows up as a problem when
  combined with our new eagerness in the face of const.

Differential Revision: https://reviews.llvm.org/D14274

llvm-svn: 290149
2016-12-20 01:05:42 +00:00
Yaxun Liu 402804b6d6 Re-commit r289252 and r289285, and fix PR31374
llvm-svn: 289787
2016-12-15 08:09:08 +00:00
Richard Smith dfe85e2d88 [c++1z] Permit constant evaluation of a call through a function pointer whose
type differs from the type of the actual function due to having a different
exception specification.

llvm-svn: 289754
2016-12-15 02:35:39 +00:00
Nico Weber 7849eeb035 Revert 289252 (and follow-up 289285), it caused PR31374
llvm-svn: 289713
2016-12-14 21:38:18 +00:00