The way this code checks whether a pointer is null is wrong for other
reasons; it doesn't actually check whether a null pointer constant is a
"constant" in the C++ standard sense. But this fix at least makes sure
we don't treat a non-null pointer as if it were null.
Fixes https://github.com/llvm/llvm-project/issues/57883
Differential Revision: https://reviews.llvm.org/D134928
This is an alternative of D120395 and D120411.
Previously we use `__bfloat16` as a typedef of `unsigned short`. The
name may give user an impression it is a brand new type to represent
BF16. So that they may use it in arithmetic operations and we don't have
a good way to block it.
To solve the problem, we introduced `__bf16` to X86 psABI and landed the
support in Clang by D130964. Now we can solve the problem by switching
intrinsics to the new type.
Reviewed By: LuoYuanke, RKSimon
Differential Revision: https://reviews.llvm.org/D132329
The parser assumes that the lexer never emits coloncolon token for C code, but this assumption no longer holds in C2x attribute namespaces. As a result, stray coloncolon tokens out of attributes cause assertion failures and hangs in release build, which this patch tries to handle.
Crash input minimal example: `T n::v`
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D133248
There are currently two options that are used to tell the compiler to perform
unsafe floating-point optimizations:
'-ffast-math' and '-funsafe-math-optimizations'.
'-ffast-math' is enabled by default. It automatically enables the driver option
'-menable-unsafe-fp-math'.
Below is a table illustrating the special operations enabled automatically by
'-ffast-math', '-funsafe-math-optimizations' and '-menable-unsafe-fp-math'
respectively.
Special Operations -ffast-math -funsafe-math-optimizations -menable-unsafe-fp-math
MathErrno 0 1 1
FiniteMathOnly 1 0 0
AllowFPReassoc 1 1 1
NoSignedZero 1 1 1
AllowRecip 1 1 1
ApproxFunc 1 1 1
RoundingMath 0 0 0
UnsafeFPMath 1 0 1
FPContract fast on on
'-ffast-math' enables '-fno-math-errno', '-ffinite-math-only',
'-funsafe-math-optimzations' and sets 'FpContract' to 'fast'. The driver option
'-menable-unsafe-fp-math' enables the same special options than
'-funsafe-math-optimizations'. This is redundant.
We propose to remove the driver option '-menable-unsafe-fp-math' and use
instead, the setting of the special operations to set the function attribute
'unsafe-fp-math'. This attribute will be enabled only if those special
operations are enabled and if 'FPContract' is either 'fast' or set to the
default value.
Differential Revision: https://reviews.llvm.org/D135097
This introduces support for nullptr and nullptr_t in C2x mode. The
proposal accepted by WG14 is:
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3042.htm
Note, there are quite a few incompatibilities with the C++ feature in
some of the edge cases of this feature. Therefore, there are some FIXME
comments in tests for testing behavior that might change after WG14 has
resolved national body comments (a process we've not yet started). So
this implementation might change slightly depending on the resolution
of comments. This is called out explicitly in the release notes as
well.
Differential Revision: https://reviews.llvm.org/D135099
When support for copy elision was initially added in e97654b2f2, it
was taking attributes from a constructor call, although that constructor
call is actually not involved. It seems more natural to use attributes
on the function returning the scoped capability, which is where it's
actually coming from. This would also support a number of interesting
use cases, like producing different scope kinds without the need for tag
types, or producing scopes from a private mutex.
Changing the behavior was surprisingly difficult: we were not handling
CXXConstructorExpr calls like regular calls but instead handled them
through the DeclStmt they're contained in. This was based on the
assumption that constructors are basically only called in variable
declarations (not true because of temporaries), and that variable
declarations necessitate constructors (not true with C++17 anymore).
Untangling this required separating construction from assigning a
variable name. When a call produces an object, we use a placeholder
til::LiteralPtr for `this`, and we collect the call expression and
placeholder in a map. Later when going through a DeclStmt, we look up
the call expression and set the placeholder to the new VarDecl.
The change has a couple of nice side effects:
* We don't miss constructor calls not contained in DeclStmts anymore,
allowing patterns like
MutexLock{&mu}, requiresMutex();
The scoped lock temporary will be destructed at the end of the full
statement, so it protects the following call without the need for a
scope, but with the ability to unlock in case of an exception.
* We support lifetime extension of temporaries. While unusual, one can
now write
const MutexLock &scope = MutexLock(&mu);
and have it behave as expected.
* Destructors used to be handled in a weird way: since there is no
expression in the AST for implicit destructor calls, we instead
provided a made-up DeclRefExpr to the variable being destructed, and
passed that instead of a CallExpr. Then later in translateAttrExpr
there was special code that knew that destructor expressions worked a
bit different.
* We were producing dummy DeclRefExprs in a number of places, this has
been eliminated. We now use til::SExprs instead.
Technically this could break existing code, but the current handling
seems unexpected enough to justify this change.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D129755
See https://reproducible-builds.org/docs/source-date-epoch/ . The environment
variable ``SOURCE_DATE_EPOCH`` been recognized by many compilers.
In GCC, if `SOURCE_DATE_EPOCH` is set, it specifies a UNIX timestamp to be used
in replacement of the current date and time in the `__DATE__` and `__TIME__`
macros. Note: GCC as of today does not update `__TIMESTAMP__` (the modification
time of the current source file) but
https://wiki.debian.org/ReproducibleBuilds/TimestampsFromCPPMacros expresses the
intention to update it.
This patches parses SOURCE_DATE_EPOCH and changes all the three macros.
In addition, in case gmtime/localtime returns null (e.g. on 64-bit Windows
gmtime returns null when the timestamp is larger than 32536850399
(3001-01-19T21:59:59Z)), use `??? ?? ????` as used by GCC.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D135045
This makes it possible to be used in all modes, instead of just when
`-fms-extensions` is enabled. Also moves the `-fms-extensions`-exclusive
traits into their own file so we can check the others aren't dependent
on this flag.
This is information that the compiler already has, and should be exposed
so that the library doesn't need to reimplement the exact same
functionality.
This was originally a part of D116280.
Depends on D135177.
Differential Revision: https://reviews.llvm.org/D135339
... as builtins.
This is information that the compiler already has, and should be exposed
so that the library doesn't need to reimplement the exact same
functionality.
This was originally a part of D116280.
Depends on D135175.
Differential Revision: https://reviews.llvm.org/D135177
This is information that the compiler already has, and should be exposed
so that the library doesn't need to reimplement the exact same
functionality.
This was originally a part of D116280.
Differential Revision: https://reviews.llvm.org/D135175
MSVC allows bit-fields to be specified as instruction operands in inline asm
blocks. Such references are resolved to the address of the allocation unit that
the named bitfield is a part of. The result is that reads and writes of such
operands will read or mutate nearby bit-fields stored in the same allocation
unit. This is a surprising behavior for which MSVC issues warning C4401,
"'<identifier>': member is bit field". Intel's icc compiler also allows such
bit-field references, but does not issue a diagnostic.
Prior to this change, Clang fails the following assertion when a bit-field is
referenced in such instructions:
clang/lib/CodeGen/CGValue.h:338: llvm::Value* clang::CodeGen::LValue::getPointer(clang::CodeGen::CodeGenFunction&) const: Assertion `isSimple()' failed.
In non-assert enabled builds, Clang's behavior appears to match the behavior
of the MSVC and icc compilers, though it is unknown if that is by design or
happenstance.
Following this change, attempts to use a bit-field as an instruction operand
in Microsoft style asm blocks is diagnosed as an error due to the risk of
unintentionally reading or writing nearby bit-fields.
Fixes https://github.com/llvm/llvm-project/issues/57791
Reviewed By: erichkeane, aaron.ballman
Differential Revision: https://reviews.llvm.org/D135500
It isn't clear that this is what it is complaining about, but looking
closer, I think this is what I got wrong here. So submitting this to
hope that the Sphinx build will be happy.
Fixes: https://github.com/llvm/llvm-project/issues/58217
This change is to remove extraneous and unnecessary ';' from after a function definition, its off by default and carries the same "code modification" warning as some of our other code manipulating changes.
Reviewed By: HazardyKnusperkeks, owenpan
Differential Revision: https://reviews.llvm.org/D135466
PCH supported for HLSL is added when compile in -cc1 mode using -include-pch for test AST.
This change add some notes about the support of PCH for HLSL.
Reviewed By: beanz
Differential Revision: https://reviews.llvm.org/D134330
This caused false positives, see comment on the code review.
> When support for copy elision was initially added in e97654b2f2, it
> was taking attributes from a constructor call, although that constructor
> call is actually not involved. It seems more natural to use attributes
> on the function returning the scoped capability, which is where it's
> actually coming from. This would also support a number of interesting
> use cases, like producing different scope kinds without the need for tag
> types, or producing scopes from a private mutex.
>
> Changing the behavior was surprisingly difficult: we were not handling
> CXXConstructorExpr calls like regular calls but instead handled them
> through the DeclStmt they're contained in. This was based on the
> assumption that constructors are basically only called in variable
> declarations (not true because of temporaries), and that variable
> declarations necessitate constructors (not true with C++17 anymore).
>
> Untangling this required separating construction from assigning a
> variable name. When a call produces an object, we use a placeholder
> til::LiteralPtr for `this`, and we collect the call expression and
> placeholder in a map. Later when going through a DeclStmt, we look up
> the call expression and set the placeholder to the new VarDecl.
>
> The change has a couple of nice side effects:
> * We don't miss constructor calls not contained in DeclStmts anymore,
> allowing patterns like
> MutexLock{&mu}, requiresMutex();
> The scoped lock temporary will be destructed at the end of the full
> statement, so it protects the following call without the need for a
> scope, but with the ability to unlock in case of an exception.
> * We support lifetime extension of temporaries. While unusual, one can
> now write
> const MutexLock &scope = MutexLock(&mu);
> and have it behave as expected.
> * Destructors used to be handled in a weird way: since there is no
> expression in the AST for implicit destructor calls, we instead
> provided a made-up DeclRefExpr to the variable being destructed, and
> passed that instead of a CallExpr. Then later in translateAttrExpr
> there was special code that knew that destructor expressions worked a
> bit different.
> * We were producing dummy DeclRefExprs in a number of places, this has
> been eliminated. We now use til::SExprs instead.
>
> Technically this could break existing code, but the current handling
> seems unexpected enough to justify this change.
>
> Reviewed By: aaron.ballman
>
> Differential Revision: https://reviews.llvm.org/D129755
This reverts commit 0041a69495 and the follow-up
warning fix in 83d93d3c11.
Previously we were stripping these normally inherited attributes during
explicit specialization. However for class template member functions
(but not function templates), MSVC keeps the attribute.
This makes Clang match that behavior, and fixes GitHub issue #54717
Differential revision: https://reviews.llvm.org/D135154
When support for copy elision was initially added in e97654b2f2, it
was taking attributes from a constructor call, although that constructor
call is actually not involved. It seems more natural to use attributes
on the function returning the scoped capability, which is where it's
actually coming from. This would also support a number of interesting
use cases, like producing different scope kinds without the need for tag
types, or producing scopes from a private mutex.
Changing the behavior was surprisingly difficult: we were not handling
CXXConstructorExpr calls like regular calls but instead handled them
through the DeclStmt they're contained in. This was based on the
assumption that constructors are basically only called in variable
declarations (not true because of temporaries), and that variable
declarations necessitate constructors (not true with C++17 anymore).
Untangling this required separating construction from assigning a
variable name. When a call produces an object, we use a placeholder
til::LiteralPtr for `this`, and we collect the call expression and
placeholder in a map. Later when going through a DeclStmt, we look up
the call expression and set the placeholder to the new VarDecl.
The change has a couple of nice side effects:
* We don't miss constructor calls not contained in DeclStmts anymore,
allowing patterns like
MutexLock{&mu}, requiresMutex();
The scoped lock temporary will be destructed at the end of the full
statement, so it protects the following call without the need for a
scope, but with the ability to unlock in case of an exception.
* We support lifetime extension of temporaries. While unusual, one can
now write
const MutexLock &scope = MutexLock(&mu);
and have it behave as expected.
* Destructors used to be handled in a weird way: since there is no
expression in the AST for implicit destructor calls, we instead
provided a made-up DeclRefExpr to the variable being destructed, and
passed that instead of a CallExpr. Then later in translateAttrExpr
there was special code that knew that destructor expressions worked a
bit different.
* We were producing dummy DeclRefExprs in a number of places, this has
been eliminated. We now use til::SExprs instead.
Technically this could break existing code, but the current handling
seems unexpected enough to justify this change.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D129755
We would issue the same diagnostic twice in the case that the K&R C
function definition is preceded by a static declaration of the function
with a prototype.
Fixes#58181
Adds a fix to the diagnostic of replacing the `= default` to `= delete`
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D134549
requires-expression
As reported: https://github.com/llvm/llvm-project/issues/57487
We properly treated a failed instantiation of a concept as a
unsatisified constraint, however, we need to do this at the 'requires
clause' level as well. This ensures that the parameters on a requires
clause that fail instantiation will cause a satisfaction failure.
This patch implements this by running requires parameter clause
instantiation under a SFINAE trap, then stores any such failure as a
requirement failure, so it can be diagnosed later.
D128745 handled DR1432 for the partial ordering of partial specializations, but
missed the handling for the partial ordering of function templates. This patch
implements the latter. While at it, also simplifies the previous implementation to
be more close to the wording without functional changes.
Fixes https://github.com/llvm/llvm-project/issues/56090
Reviewed By: erichkeane, #clang-language-wg, mizvekov
Differential Revision: https://reviews.llvm.org/D133683
This adds support under AArch64 for the target("..") attributes. The
current parsing is very X86-shaped, this patch attempts to bring it line
with the GCC implementation from
https://gcc.gnu.org/onlinedocs/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes.
The supported formats are:
- "arch=<arch>" strings, that specify the architecture features for a
function as per the -march=arch+feature option.
- "cpu=<cpu>" strings, that specify the target-cpu and any implied
atributes as per the -mcpu=cpu+feature option.
- "tune=<cpu>" strings, that specify the tune-cpu cpu for a function as
per -mtune.
- "+<feature>", "+no<feature>" enables/disables the specific feature, for
compatibility with GCC target attributes.
- "<feature>", "no-<feature>" enabled/disables the specific feature, for
backward compatibility with previous releases.
To do this, the parsing of target attributes has been moved into
TargetInfo to give the target the opportunity to override the existing
parsing. The only non-aarch64 change should be a minor alteration to the
error message, specifying using "CPU" to describe the cpu, not
"architecture", and the DuplicateArch/Tune from ParsedTargetAttr have
been combined into a single option.
Differential Revision: https://reviews.llvm.org/D133848
Change the default config file loading logic to be more flexible
and more readable at the same time. The new algorithm focuses on four
locations, in order:
1. <triple>-<mode>.cfg using real driver mode
2. <triple>-<mode>.cfg using executable suffix
3. <triple>.cfg + <mode>.cfg using real driver mode
4. <triple>.cfg + <mode>.cfg using executable suffix
This is meant to preserve reasonable level of compatibility with
the existing use, while introducing more flexibility and making the code
simpler. Notably:
1. In this layout, the actual target triple is normally respected,
and e.g. in `-m32` build the `x86_64-*` configs will never be used.
2. Both real driver mode (preferable) and executable suffix are
supported. This permits correctly handling calls with explicit
`--driver-mode=` while at the same time preserving compatibility
with the existing code.
3. The first two locations provide users with the ability to override
configuration per specific target+mode combinaton, while the next two
make it possible to independently specify per-target and per-mode
configuration.
4. All config file locations are applicable independently of whether
clang is started via a prefixed executable, or bare `clang`.
5. If the target is not explicitly specified and the executable prefix
does not name a valid triple, it is used instead of the actual target
triple for backwards compatibility.
This is particularly meant to address Gentoo's use case for
configuration files: to configure the default runtimes (i.e. `-rtlib=`,
`-stdlib=`) and `--gcc-install-dir=` for all the relevant drivers,
as well as to make it more convenient for users to override `-W` flags
to test compatibility with future versions of Clang easier.
Differential Revision: https://reviews.llvm.org/D134337
Driver options usually use `Joined` instead of `Separate`. It is also weird that
`--config-system-dir=`/etc exist while `--config=` did not exist.
Reviewed By: mgorny
Differential Revision: https://reviews.llvm.org/D134790
A code block was separated from its release note, so this re-associates
them again. It also adds an example code block to another potentially
breaking change entry.
This implements WG14 N2927 and WG14 N2930, which together define the
feature for typeof and typeof_unqual, which get the type of their
argument as either fully qualified or fully unqualified. The argument
to either operator is either a type name or an expression. If given a
type name, the type information is pulled directly from the given name.
If given an expression, the type information is pulled from the
expression. Recursive use of these operators is allowed and has the
expected behavior (the innermost operator is resolved to a type, and
that's used to resolve the next layer of typeof specifier, until a
fully resolved type is determined.
Note, we already supported typeof in GNU mode as a non-conforming
extension and we are *not* exposing typeof_unqual as a non-conforming
extension in that mode, nor are we exposing typeof or typeof_unqual as
a nonconforming extension in other language modes. The GNU variant of
typeof supports a form where the parentheses are elided from the
operator when given an expression (e.g., typeof 0 i = 12;). When in C2x
mode, we do not support this extension.
Differential Revision: https://reviews.llvm.org/D134286
This patch implements P0634r3 that removes the need for 'typename' in certain contexts.
For example,
```
template <typename T>
using foo = T::type; // ok
```
This is also allowed in previous language versions as an extension, because I think it's pretty useful. :)
Reviewed By: #clang-language-wg, erichkeane
Differential Revision: https://reviews.llvm.org/D53847
This eagerly reports use of undef values when passed to noundef
parameters or returned from noundef functions.
This also decreases binary sizes under msan.
To go back to the previous behavior, pass `-fno-sanitize-memory-param-retval`.
Reviewed By: vitalybuka, MaskRay
Differential Revision: https://reviews.llvm.org/D134669
Although using-enum's grammar is 'using elaborated-enum-specifier',
the lookup for the enum is ordinary lookup (and not the tagged-type
lookup that normally occurs wth an tagged-type specifier). Thus (a)
we can find typedefs and (b) do not find enum tags hidden by a non-tag
name (the struct stat thing).
This reimplements that part of using-enum handling, to address DR2621,
where clang's behaviour does not match std intent (and other
compilers).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D134283
This reverts commit 192d69f7e6.
This fixes the condition to check whether this is a situation where we
are in a recovery-expr'ed concept a little better, so we don't access an
inactive member of a union, which should make the bots happy.
Differential Revision: https://reviews.llvm.org/D134542
Eli Friedman