Otherwise callers of these functions have to check both the return value
for and the contents of the returned llvm::Optional.
Fixes#53742
Differential Revision: https://reviews.llvm.org/D119525
Adds a new option InsertBraces to insert the optional braces after
if, else, for, while, and do in C++.
Differential Revision: https://reviews.llvm.org/D120217
This adds support for http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2764.pdf,
which was adopted at the Feb 2022 WG14 meeting. That paper adds
[[noreturn]] and [[_Noreturn]] to the list of supported attributes in
C2x. These attributes have the same semantics as the [[noreturn]]
attribute in C++.
The [[_Noreturn]] attribute was added as a deprecated feature so that
translation units which include <stdnoreturn.h> do not get an error on
use of [[noreturn]] because the macro expands to _Noreturn. Users can
use -Wno-deprecated-attributes to silence the diagnostic.
Use of <stdnotreturn.h> or the noreturn macro were both deprecated.
Users can define the _CLANG_DISABLE_CRT_DEPRECATION_WARNINGS macro to
suppress the deprecation diagnostics coming from the header file.
When forming the function type from a declarator, we look for an
overloadable attribute before issuing a diagnostic in C about a
function signature containing only .... When the attribute is present,
we allow such a declaration for compatibility with the overloading
rules in C++. However, we were not looking for the attribute in all of
the places it is legal to write it on a declarator and so we only
accepted the signature in some forms and incorrectly rejected the
signature in others.
We now check for the attribute preceding the declarator instead of only
being applied to the declarator directly.
The introduction and some examples are on this page:
https://devblogs.microsoft.com/cppblog/announcing-jmc-stepping-in-visual-studio/
The `/JMC` flag enables these instrumentations:
- Insert at the beginning of every function immediately after the prologue with
a call to `void __fastcall __CheckForDebuggerJustMyCode(unsigned char *JMC_flag)`.
The argument for `__CheckForDebuggerJustMyCode` is the address of a boolean
global variable (the global variable is initialized to 1) with the name
convention `__<hash>_<filename>`. All such global variables are placed in
the `.msvcjmc` section.
- The `<hash>` part of `__<hash>_<filename>` has a one-to-one mapping
with a directory path. MSVC uses some unknown hashing function. Here I
used DJB.
- Add a dummy/empty COMDAT function `__JustMyCode_Default`.
- Add `/alternatename:__CheckForDebuggerJustMyCode=__JustMyCode_Default` link
option via ".drectve" section. This is to prevent failure in
case `__CheckForDebuggerJustMyCode` is not provided during linking.
Implementation:
All the instrumentations are implemented in an IR codegen pass. The pass is placed immediately before CodeGenPrepare pass. This is to not interfere with mid-end optimizations and make the instrumentation target-independent (I'm still working on an ELF port in a separate patch).
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D118428
These changes make the Clang parser recognize expression parameter pack
expansion and initializer lists in attribute arguments. Because
expression parameter pack expansion requires additional handling while
creating and instantiating templates, the support for them must be
explicitly supported through the AcceptsExprPack flag.
Handling expression pack expansions may require a delay to when the
arguments of an attribute are correctly populated. To this end,
attributes that are set to accept these - through setting the
AcceptsExprPack flag - will automatically have an additional variadic
expression argument member named DelayedArgs. This member is not
exposed the same way other arguments are but is set through the new
CreateWithDelayedArgs creator function generated for applicable
attributes.
To illustrate how to implement support for expression pack expansion
support, clang::annotate is made to support pack expansions. This is
done by making handleAnnotationAttr delay setting the actual attribute
arguments until after template instantiation if it was unable to
populate the arguments due to dependencies in the parsed expressions.
Implement P2128R6 in C++23 mode.
Unlike GCC's implementation, this doesn't try to recover when a user
meant to use a comma expression.
Because the syntax changes meaning in C++23, the patch is *NOT*
implemented as an extension. Instead, declaring an array with not
exactly 1 parameter is an error in older languages modes. There is an
off-by-default extension warning in C++23 mode.
Unlike the standard, we supports default arguments;
Ie, we assume, based on conversations in WG21, that the proposed
resolution to CWG2507 will be accepted.
We allow arrays OpenMP sections and C++23 multidimensional array to
coexist:
[a , b] multi dimensional array
[a : b] open mp section
[a, b: c] // error
The rest of the patch is relatively straight forward: we take care to
support an arbitrary number of arguments everywhere.
This patch adds more documentation for the OpenMP offloading driver.
This includes a new file that describes the overall pipeline becuase
that was not previously explained in full elsewhere.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D118815
This updates all the non-runtime project release notes to use the
version number from CMake instead of the hard-coded version numbers
in conf.py.
It also hides warnings about pre-releases when the git suffix
is dropped from the LLVM version in CMake.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D112181
This patch introduces a linker wrapper tool that allows us to preprocess
files before they are sent to the linker. This adds a dummy action and
job to the driver stage that builds the linker command as usual and then
replaces the command line with the wrapper tool.
Depends on D116543
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D116544
to give users a final warning that they need to migrate away. They could still
use -flegacy-pass-manager for Clang 14.0.0, but the functionality may not work
for 15.0.0.
-fexperimental-new-pass-manager is a no-op for default builds, so not urgent to
be removed for 14.0.0.
clang/test/Frontend/optimization-remark-with-hotness.c is removed because its
new PM replacement optimization-remark-with-hotness-new-pm.c exists.
Reviewed By: aeubanks, nikic
Differential Revision: https://reviews.llvm.org/D118313
Part of the _BitInt feature in C2x
(http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf) is a new
macro in limits.h named BITINT_MAXWIDTH that can be used to determine
the maximum width of a bit-precise integer type. This macro must expand
to a value that is at least as large as ULLONG_WIDTH.
This adds an implementation-defined macro named __BITINT_MAXWIDTH__ to
specify that value, which is used by limits.h for the standard macro.
This also limits the maximum bit width to 128 bits because backends do
not currently support all mathematical operations (such as division) on
wider types yet. This maximum is expected to be increased in the future.
This matches GCC: https://godbolt.org/z/sM5q95PGY
I realize this is an API break for clang+clang - so I'm totally open to
discussing how we should deal with that. If Apple wants to keep the
Clang layout indefinitely, if we want to put a flag on this so non-Apple
folks can opt out of this fix/new behavior.
Differential Revision: https://reviews.llvm.org/D117616
With 118f966b46, Clang matches GCC's behaviour and allows enabling
-Wdeclaration-after-statement with C99 and later.
However, the check for mixing declarations and code is not a constant time
algorithm, and therefore should be guarded with Diags.isIgnored().
Furthermore, improve test coverage with: non-pedantic C89 with the
warning; C11 with the warning; and when using -Wall.
Finally, mention the changed behaviour in ReleaseNotes.rst.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D117232
This patch adds support for the MSVC /HOTPATCH flag: https://docs.microsoft.com/sv-se/cpp/build/reference/hotpatch-create-hotpatchable-image?view=msvc-170&viewFallbackFrom=vs-2019
The flag is translated to a new -fms-hotpatch flag, which in turn adds a 'patchable-function' attribute for each function in the TU. This is then picked up by the PatchableFunction pass which would generate a TargetOpcode::PATCHABLE_OP of minsize = 2 (which means the target instruction must resolve to at least two bytes). TargetOpcode::PATCHABLE_OP is only implemented for x86/x64. When targetting ARM/ARM64, /HOTPATCH isn't required (instructions are always 2/4 bytes and suitable for hotpatching).
Additionally, when using /Z7, we generate a 'hot patchable' flag in the CodeView debug stream, in the S_COMPILE3 record. This flag is then picked up by LLD (or link.exe) and is used in conjunction with the linker /FUNCTIONPADMIN flag to generate extra space before each function, to accommodate for live patching long jumps. Please see: d703b92296/lld/COFF/Writer.cpp (L1298)
The outcome is that we can finally use Live++ or Recode along with clang-cl.
NOTE: It seems that MSVC cl.exe always enables /HOTPATCH on x64 by default, although if we did the same I thought we might generate sub-optimal code (if this flag was active by default). Additionally, MSVC always generates a .debug$S section and a S_COMPILE3 record, which Clang doesn't do without /Z7. Therefore, the following MSVC command-line "cl /c file.cpp" would have to be written with Clang such as "clang-cl /c file.cpp /HOTPATCH /Z7" in order to obtain the same result.
Depends on D43002, D80833 and D81301 for the full feature.
Differential Revision: https://reviews.llvm.org/D116511
C17 deprecated ATOMIC_VAR_INIT with the resolution of DR 485. C++
followed suit when adopting P0883R2 for C++20, but additionally chose
to deprecate ATOMIC_FLAG_INIT at the same time despite the macro still
being required in C. This patch marks both macros as deprecated when
appropriate to do so.
This style is similar to AlwaysBreak, but places closing brackets on new lines.
For example, if you have a multiline parameter list, clang-format currently only supports breaking per-parameter, but places the closing bracket on the line of the last parameter.
Function(
param1,
param2,
param3);
A style supported by other code styling tools (e.g. rustfmt) is to allow the closing brackets to be placed on their own line, aiding the user in being able to quickly infer the bounds of the block of code.
Function(
param1,
param2,
param3
);
For prior work on a similar feature, see: https://reviews.llvm.org/D33029.
Note: This currently only supports block indentation for closing parentheses.
Differential Revision: https://reviews.llvm.org/D109557
This completes the implementation of
WG14 N2412 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf),
which standardizes C on a twos complement representation for integer
types. The only work that remained there was to define the correct
macros in the standard headers, which this patch does.
I noticed that the following case would compile in Clang but not GCC:
void *x(void) {
void *p = &&foo;
asm goto ("# %0\n\t# %l1":"+r"(p):::foo);
foo:;
return p;
}
Changing the output template above from %l2 would compile in GCC but not
Clang.
This demonstrates that when using tied outputs (say via the "+r" output
constraint), the hidden inputs occur or are numbered BEFORE the labels,
at least with GCC.
In fact, GCC does denote this in its documentation:
https://gcc.gnu.org/onlinedocs/gcc-11.2.0/gcc/Extended-Asm.html#Goto-Labels
> Output operand with constraint modifier ‘+’ is counted as two operands
> because it is considered as one output and one input operand.
For the sake of compatibility, I think it's worthwhile to just make this
change.
It's better to use symbolic names for compatibility (especially now
between released version of Clang that support asm goto with outputs).
ie. %l1 from the above would be %l[foo]. The GCC docs also make this
recommendation.
Also, I cleaned up some cruft in GCCAsmStmt::getNamedOperand. AFAICT,
NumPlusOperands was no longer used, though I couldn't find which commit
didn't clean that up correctly.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98096
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103640
Link: https://gcc.gnu.org/onlinedocs/gcc-11.2.0/gcc/Extended-Asm.html#Goto-Labels
Reviewed By: void
Differential Revision: https://reviews.llvm.org/D115471
Previously this was documented as having the behavior of the
"target's native float-to-int conversion". After D115804, clang
uses saturating FP cast intrinsics which have the same behavior
on all targets.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D116856
This change adds an option AfterOverloadedOperator in SpaceBeforeParensOptions to add a space between overloaded operator and opening parentheses in clang-format.
Reviewed By: MyDeveloperDay, curdeius, HazardyKnusperkeks
Differential Revision: https://reviews.llvm.org/D116283
This commit resolves GitHub issue #45895 (Bugzilla #46550), to
add or remove empty line between definition blocks including
namespaces, classes, structs, enums and functions.
Reviewed By: MyDeveloperDay, curdeius, HazardyKnusperkeks
Differential Revision: https://reviews.llvm.org/D116314
This diff extends the -style=file option to allow a config file to be specified explicitly. This is useful (for instance) when adding IDE commands to reformat code to a personal style.
Usage: `clang-format -style=file:<path/to/config/file> ...`
Reviewed By: HazardyKnusperkeks, curdeius, MyDeveloperDay, zwliew
Differential Revision: https://reviews.llvm.org/D72326
Extends response file expansion to recognize `<CFGDIR>` and expand to the
current file's directory. This makes it much easier to author clang config
files rooted in portable, potentially not-installed SDK directories.
A typical use case may be something like the following:
```
# sample_sdk.cfg
--target=sample
-isystem <CFGDIR>/include
-L <CFGDIR>/lib
-T <CFGDIR>/ldscripts/link.ld
```
Reviewed By: sepavloff
Differential Revision: https://reviews.llvm.org/D115604
This reverts commit cc56c66f27.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.
Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().
Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
breaking existing patterns and following the precedent of ElaboratedType.
Scope:
- This does not cover types associated with template names introduced by
using declarations. A future patch should introduce a sugar TemplateName
variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
probably any other matchers, though more may be useful later.
Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
Previously, typeLoc(loc(recordType())) matched whether a struct was
referred to by its original scope or introduced via using-decl.
Now, the using-decl case is not matched, and needs a separate matcher.
This is similar to the case of typedefs but nevertheless both adds
complexity and breaks existing code.
Differential Revision: https://reviews.llvm.org/D114251
In 2015-05, GCC added the configure option `--enable-default-pie`. When enabled,
* in the absence of -fno-pic/-fpie/-fpic (and their upper-case variants), -fPIE is the default.
* in the absence of -no-pie/-pie/-shared/-static/-static-pie, -pie is the default.
This has been adopted by all(?) major distros.
I think default PIE is the majority in the Linux world, but
--disable-default-pie users is not that uncommon because GCC upstream hasn't
switched the default yet (https://gcc.gnu.org/PR103398).
This patch add CLANG_DEFAULT_PIE_ON_LINUX which allows distros to use default PIE.
The option is justified as its adoption can be very high among Linux distros
to make Clang default match GCC, and is likely a future-new-default, at which
point we will remove CLANG_DEFAULT_PIE_ON_LINUX.
The lit feature `default-pie-on-linux` can be handy to exclude default PIE sensitive tests.
Reviewed By: foutrelis, sylvestre.ledru, thesamesam
Differential Revision: https://reviews.llvm.org/D113372
Some users have a need to control attribute extension diagnostics
independent of other extension diagnostics. Consider something like use
of [[nodiscard]] within C++11:
```
[[nodiscard]]
int f();
```
If compiled with -Wc++17-extensions enabled, this will produce warning:
use of the 'nodiscard' attribute is a C++17 extension. This diagnostic
is correct -- using [[nodiscard]] in C++11 mode is a C++17 extension.
And the behavior of __has_cpp_attribute(nodiscard) is also correct --
we support [[nodiscard]] in C++11 mode as a conforming extension. But
this makes use of -Werror or -pedantic-errors` builds more onerous.
This patch adds diagnostic groups for attribute extensions so that
users can selectively disable attribute extension diagnostics. I
believe this is preferable to requiring users to specify additional
flags because it means -Wc++17-extensions continues to be the way we
enable all C++17-related extension diagnostics. It would be quite easy
for someone to use that flag thinking they're protected from some
portability issues without realizing it skipped attribute extensions if
we went the other way.
This addresses PR33518.
Nathan James