Commit Graph

732 Commits

Author SHA1 Message Date
Corentin Jabot 6882ca9aff [Clang] Adjust extension warnings for delimited sequences
WG21 approved delimited escape sequences and named escape
sequences.
Adjust the extension warnings accordingly, and update
the release notes.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D129664
2022-07-14 07:50:58 +02:00
Corentin Jabot d4892a168f [Clang] Add a warning on invalid UTF-8 in comments.
Introduce an off-by default `-Winvalid-utf8` warning
that detects invalid UTF-8 code units sequences in comments.

Invalid UTF-8 in other places is already diagnosed,
as that cannot appear in identifiers and other grammar constructs.

The warning is off by default as its likely to be somewhat disruptive
otherwise.

This warning allows clang to conform to the yet-to be approved WG21
"P2295R5 Support for UTF-8 as a portable source file encoding"
paper.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D128059
2022-07-13 10:19:26 +02:00
Jonas Devlieghere a262f4dbd7 Revert "[Clang] Add a warning on invalid UTF-8 in comments."
This reverts commit cc309721d2 because it
breaks the following tests on GreenDragon:

  TestDataFormatterObjCCF.py
  TestDataFormatterObjCExpr.py
  TestDataFormatterObjCKVO.py
  TestDataFormatterObjCNSBundle.py
  TestDataFormatterObjCNSData.py
  TestDataFormatterObjCNSError.py
  TestDataFormatterObjCNSNumber.py
  TestDataFormatterObjCNSURL.py
  TestDataFormatterObjCPlain.py
  TestDataFormatterObjNSException.py

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45288/
2022-07-12 15:22:29 -07:00
Roy Jacobson 0b89d1d59f [Sema] Add deprecation warnings for some compiler provided __has_* type traits
Some compiler provided type traits like __has_trivial_constructor have been documented
as deprecated for quite some time.
Still, some people apparently still use them, even though mixing them with concepts
and with deleted functions leads to weird results. There's also disagreement about some
edge cases between GCC (which Clang claims to follow) and MSVC.

This patch adds deprecation warnings for the usage of those builtins, except for __has_trivial_destructor
which doesn't have a GCC alternative.

I made the warning on by default, so I had to silence it for some tests but it's not too many.

Some (decade old) history of issues with those builtins:
https://github.com/llvm/llvm-project/issues/18187
https://github.com/llvm/llvm-project/issues/18559
https://github.com/llvm/llvm-project/issues/22161
https://github.com/llvm/llvm-project/issues/33063

The abseil usage of them that triggered me to add this warning:
https://github.com/abseil/abseil-cpp/issues/1201

Weird interaction of those builtins with C++20's conditionally trivial special member functions:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106085

Reviewed By: #clang-language-wg, aaron.ballman

Differential Revision: https://reviews.llvm.org/D129170
2022-07-12 19:24:17 +03:00
Nick Desaulniers 2240d72f15 [X86] initial -mfunction-return=thunk-extern support
Adds support for:
* `-mfunction-return=<value>` command line flag, and
* `__attribute__((function_return("<value>")))` function attribute

Where the supported <value>s are:
* keep (disable)
* thunk-extern (enable)

thunk-extern enables clang to change ret instructions into jmps to an
external symbol named __x86_return_thunk, implemented as a new
MachineFunctionPass named "x86-return-thunks", keyed off the new IR
attribute fn_ret_thunk_extern.

The symbol __x86_return_thunk is expected to be provided by the runtime
the compiled code is linked against and is not defined by the compiler.
Enabling this option alone doesn't provide mitigations without
corresponding definitions of __x86_return_thunk!

This new MachineFunctionPass is very similar to "x86-lvi-ret".

The <value>s "thunk" and "thunk-inline" are currently unsupported. It's
not clear yet that they are necessary: whether the thunk pattern they
would emit is beneficial or used anywhere.

Should the <value>s "thunk" and "thunk-inline" become necessary,
x86-return-thunks could probably be merged into x86-retpoline-thunks
which has pre-existing machinery for emitting thunks (which could be
used to implement the <value> "thunk").

Has been found to build+boot with corresponding Linux
kernel patches. This helps the Linux kernel mitigate RETBLEED.
* CVE-2022-23816
* CVE-2022-28693
* CVE-2022-29901

See also:
* "RETBLEED: Arbitrary Speculative Code Execution with Return
Instructions."
* AMD SECURITY NOTICE AMD-SN-1037: AMD CPU Branch Type Confusion
* TECHNICAL GUIDANCE FOR MITIGATING BRANCH TYPE CONFUSION REVISION 1.0
  2022-07-12
* Return Stack Buffer Underflow / Return Stack Buffer Underflow /
  CVE-2022-29901, CVE-2022-28693 / INTEL-SA-00702

SystemZ may eventually want to support "thunk-extern" and "thunk"; both
options are used by the Linux kernel's CONFIG_EXPOLINE.

This functionality has been available in GCC since the 8.1 release, and
was backported to the 7.3 release.

Many thanks for folks that provided discrete review off list due to the
embargoed nature of this hardware vulnerability. Many Bothans died to
bring us this information.

Link: https://www.youtube.com/watch?v=IF6HbCKQHK8
Link: https://github.com/llvm/llvm-project/issues/54404
Link: https://gcc.gnu.org/legacy-ml/gcc-patches/2018-01/msg01197.html
Link: https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/return-stack-buffer-underflow.html
Link: https://arstechnica.com/information-technology/2022/07/intel-and-amd-cpus-vulnerable-to-a-new-speculative-execution-attack/?comments=1
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce114c866860aa9eae3f50974efc68241186ba60
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00702.html
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00707.html

Reviewed By: aaron.ballman, craig.topper

Differential Revision: https://reviews.llvm.org/D129572
2022-07-12 09:17:54 -07:00
Chuanqi Xu 4b95a5a772 [Modules] Add ODR Check for concepts
Closing https://github.com/llvm/llvm-project/issues/56310

Previously we don't check the contents of concept so it might merge
inconsistent results.

Important Note: this patch might break existing code but the behavior
might be right.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D129104
2022-07-12 23:45:53 +08:00
Corentin Jabot cc309721d2 [Clang] Add a warning on invalid UTF-8 in comments.
Introduce an off-by default `-Winvalid-utf8` warning
that detects invalid UTF-8 code units sequences in comments.

Invalid UTF-8 in other places is already diagnosed,
as that cannot appear in identifiers and other grammar constructs.

The warning is off by default as its likely to be somewhat disruptive
otherwise.

This warning allows clang to conform to the yet-to be approved WG21
"P2295R5 Support for UTF-8 as a portable source file encoding"
paper.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D128059
2022-07-12 14:34:30 +02:00
Aaron Ballman 3cfa32a71e Undeprecate ATOMIC_FLAG_INIT in C++
C++20 deprecated ATOMIC_FLAG_INIT thinking it was deprecated in C when it
wasn't. It is expected to be undeprecated in C++23 as part of LWG3659
(https://wg21.link/LWG3659), which is currently Tentatively Ready.

This handles the case where the user includes <stdatomic.h> in C++ code in a
freestanding compile mode. The corollary libc++ changes are in
1544d1f9fd.
2022-07-12 06:48:31 -04:00
Xiang1 Zhang a45dd3d814 [X86] Support -mstack-protector-guard-symbol
Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D129346
2022-07-12 10:17:00 +08:00
Xiang1 Zhang 643786213b Revert "[X86] Support -mstack-protector-guard-symbol"
This reverts commit efbaad1c4a.
due to miss adding review info.
2022-07-12 10:14:32 +08:00
Xiang1 Zhang efbaad1c4a [X86] Support -mstack-protector-guard-symbol 2022-07-12 10:13:48 +08:00
serge-sans-paille da6a14b91a [clang] Enforce instantiation of constexpr template functions during non-constexpr evaluation
Otherwise these functions are not instantiated and we end up with an undefined
symbol.

Fix #55560

Differential Revision: https://reviews.llvm.org/D128119
2022-07-10 08:40:03 +02:00
Corentin Jabot 50416e5454 Revert "[Clang] Add a warning on invalid UTF-8 in comments."
It is probable thart this change crashes on the powerpc bots.

This reverts commit 355532a149.
2022-07-09 17:18:35 +02:00
Corentin Jabot 355532a149 [Clang] Add a warning on invalid UTF-8 in comments.
Introduce an off-by default `-Winvalid-utf8` warning
that detects invalid UTF-8 code units sequences in comments.

Invalid UTF-8 in other places is already diagnosed,
as that cannot appear in identifiers and other grammar constructs.

The warning is off by default as its likely to be somewhat disruptive
otherwise.

This warning allows clang to conform to the yet-to be approved WG21
"P2295R5 Support for UTF-8 as a portable source file encoding"
paper.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D128059
2022-07-09 11:26:45 +02:00
Nathan James 54f57d3847
[clang] Add a fixit for warn-self-assign if LHS is a field with the same name as parameter on RHS
Add a fix-it for the common case of setters/constructors using parameters with the same name as fields
```lang=c++
struct A{
  int X;
  A(int X) { /*this->*/X = X; }
  void setX(int X) { /*this->*/X = X;
};
```

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D129202
2022-07-09 08:28:07 +01:00
serge-sans-paille cc5b77273a [clang] Introduce -Warray-parameter
This warning exist in GCC[0] and warns about re-declarations of functions
involving arguments of array or pointer types of inconsistent kinds or forms.

This is not the exact same implementation as GCC's : there's no warning level
and that flag has no effect on -Warray-bounds.

[0] https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gcc/Warning-Options.html#index-Wno-array-parameter

Differential Revision: https://reviews.llvm.org/D128449
2022-07-08 22:36:05 +02:00
tlattner eb1ffd817c Update references to Discourse instead of the mailing lists.
Update the references to the old Mailman mailing lists to point to Discourse forums.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D128766
2022-07-08 11:16:47 -07:00
Peter Waller 2db2a4e112 [doc][ReleaseNotes] Document AArch64 SVE ABI fix from D127209
D127209 fixed LLVM to bring it in line with the AAPCS. The fix affects
functions where the first SVE parameter appears in the 9th or later
arguments, and the function does not return an SVE type.

Differential Revision: https://reviews.llvm.org/D129135
2022-07-07 10:55:40 +00:00
Nico Weber e9fe20dab3 Revert "[Clang] Add a warning on invalid UTF-8 in comments."
This reverts commit 4174f0ca61.

Also revert follow-up "[Clang] Fix invalid utf-8 detection"
This reverts commit bf45e27a67.

The second commit broke tests, see comments on
https://reviews.llvm.org/D129223, and it sounds like the first
commit isn't valid without the second one. So reverting both for now.
2022-07-06 22:51:52 +02:00
Corentin Jabot 4174f0ca61 [Clang] Add a warning on invalid UTF-8 in comments.
Introduce an off-by default `-Winvalid-utf8` warning
that detects invalid UTF-8 code units sequences in comments.

Invalid UTF-8 in other places is already diagnosed,
as that cannot appear in identifiers and other grammar constructs.

The warning is off by default as its likely to be somewhat disruptive
otherwise.

This warning allows clang to conform to the yet-to be approved WG21
"P2295R5 Support for UTF-8 as a portable source file encoding"
paper.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D128059
2022-07-06 21:18:29 +02:00
Corentin Jabot fb06dd3e8c Revert "[Clang] Add a warning on invalid UTF-8 in comments."
Reverting while I investigate build failures

This reverts commit e3dc56805f.
2022-07-06 19:45:12 +02:00
Corentin Jabot e3dc56805f [Clang] Add a warning on invalid UTF-8 in comments.
Introduce an off-by default `-Winvalid-utf8` warning
that detects invalid UTF-8 code units sequences in comments.

Invalid UTF-8 in other places is already diagnosed,
as that cannot appear in identifiers and other grammar constructs.

The warning is off by default as its likely to be somewhat disruptive
otherwise.

This warning allows clang to conform to the yet-to be approved WG21
"P2295R5 Support for UTF-8 as a portable source file encoding"
paper.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D128059
2022-07-06 17:59:44 +02:00
Paul Robinson 08e4fe6c61 [X86] Add RDPRU instruction
Add support for the RDPRU instruction on Zen2 processors.

User-facing features:

- Clang option -m[no-]rdpru to enable/disable the feature
- Support is implicit for znver2/znver3 processors
- Preprocessor symbol __RDPRU__ to indicate support
- Header rdpruintrin.h to define intrinsics
- "rdpru" mnemonic supported for assembler code

Internal features:

- Clang builtin __builtin_ia32_rdpru
- IR intrinsic @llvm.x86.rdpru

Differential Revision: https://reviews.llvm.org/D128934
2022-07-06 07:17:47 -07:00
Félix Cloutier 92edd74b37 Allow non-variadic functions to be attributed with `__attribute__((format))`
Clang only allows you to use __attribute__((format)) on variadic functions. There are legit use cases for __attribute__((format)) on non-variadic functions, such as:

(1) variadic templates

```c++
template<typename… Args>
void print(const char *fmt, Args… &&args) __attribute__((format(1, 2))); // error: format attribute requires variadic function
```

(2) functions which take fixed arguments and a custom format:

```c++
void print_number_string(const char *fmt, unsigned number, const char *string) __attribute__((format(1, 2)));
// ^error: format attribute requires variadic function

void foo(void) {
    print_number_string(“%08x %s\n”, 0xdeadbeef, “hello”);
    print_number_string(“%d %s”, 0xcafebabe, “bar”);
}
```

This change allows Clang users to attach __attribute__((format)) to non-variadic functions, including functions with C++ variadic templates. It replaces the error with a GCC compatibility warning and improves the type checker to ensure that received arrays are treated like pointers (this is a possibility in C++ since references to template types can bind to arrays).

Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D112579
rdar://84629099
2022-07-05 17:26:11 -07:00
Tobias Hieta e6ff553979 [clang-extdef-mapping] Directly process .ast files
When doing CTU analysis setup you pre-compile .cpp to .ast and then
you run clang-extdef-mapping on the .cpp file as well. This is a
pretty slow process since we have to recompile the file each time.

With this patch you can now run clang-extdef-mapping directly on
the .ast file. That saves a lot of time.

I tried this on llvm/lib/AsmParser/Parser.cpp and running
extdef-mapping on the .cpp file took 5.4s on my machine.

While running it on the .ast file it took 2s.

This can save a lot of time for the setup phase of CTU analysis.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D128704
2022-07-05 13:45:52 +02:00
Archibald Elliott 1666f09933 [ARM] Add Support for Cortex-M85
This patch adds support for Arm's Cortex-M85 CPU. The Cortex-M85 CPU is
an Arm v8.1m Mainline CPU, with optional support for MVE and PACBTI,
both of which are enabled by default.

Parts have been coauthored by by Mark Murray, Alexandros Lamprineas and
David Green.

Differential Revision: https://reviews.llvm.org/D128415
2022-07-05 10:43:31 +01:00
Erich Keane 258c3aee54 Revert "Re-apply "Deferred Concept Instantiation Implementation"""
This reverts commit befa8cf087.

Apparently this breaks some libc++ builds with an apparent assertion,
 so I'm looking into that .
2022-07-01 11:20:16 -07:00
Erich Keane befa8cf087 Re-apply "Deferred Concept Instantiation Implementation""
This reverts commit d4d47e574e.

This fixes the lldb crash that was observed by ensuring that our
friend-'template contains reference to' TreeTransform properly handles a
TemplateDecl.
2022-07-01 06:51:38 -07:00
Rashmi Mudduluru eb1d908e5c Adds AST matcher for ObjCStringLiteral
Differential Revision: https://reviews.llvm.org/D128103
2022-06-30 15:20:10 -07:00
Jonas Devlieghere d4d47e574e
Revert "Deferred Concept Instantiation Implementation"
This reverts commit 2f20743952 because it
triggers an assertion when building an LLDB test program:

  Assertion failed: (InstantiatingSpecializations.empty() && "failed to
  clean up an InstantiatingTemplate?"), function ~Sema, file
  /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/clang/lib/Sema/Sema.cpp,
  line 458.

More details in https://reviews.llvm.org/D126907.
2022-06-30 11:43:10 -07:00
Erich Keane 2f20743952 Deferred Concept Instantiation Implementation
This is a continuation of D119544.  Based on @rsmith 's feed back
showing me https://eel.is/c++draft/temp#friend-9, We should properly
handle friend functions now.

Differential Revision: https://reviews.llvm.org/D126907
2022-06-30 06:47:11 -07:00
Prathit Aswar cde1df4ca4 Correct -Winfinite-recursion warning on potentially-unevaluated operand
Fixing issue "incorrect -Winfinite-recursion warning on potentially-
unevaluated operand".

We add a dedicated visit function (VisitCXXTypeidExpr) for typeid,
instead of using the default (VisitStmt). In this new function we skip
over building the CFG for unevaluated operands of typeid.

Fixes #21668

Differential Revision: https://reviews.llvm.org/D128747
2022-06-30 09:09:28 -04:00
Phoebe Wang abeeae570e [X86] Support `_Float16` on SSE2 and up
This is split from D113107 to address #56204 and https://discourse.llvm.org/t/how-to-build-compiler-rt-for-new-x86-half-float-abi/63366

Reviewed By: zahiraam, rjmccall, bkramer, MaskRay

Differential Revision: https://reviews.llvm.org/D128571
2022-06-30 17:21:37 +08:00
Corentin Jabot 64ab2b1dcc Improve handling of static assert messages.
Instead of dumping the string literal (which
quotes it and escape every non-ascii symbol),
we can use the content of the string when it is a
8 byte string.

Wide, UTF-8/UTF-16/32 strings are still completely
escaped, until we clarify how these entities should
behave (cf https://wg21.link/p2361).

`FormatDiagnostic` is modified to escape
non printable characters and invalid UTF-8.

This ensures that unicode characters, spaces and new
lines are properly rendered in static messages.
This make clang more consistent with other implementation
and fixes this tweet
https://twitter.com/jfbastien/status/1298307325443231744 :)

Of note, `PaddingChecker` did print out new lines that were
later removed by the diagnostic printing code.
To be consistent with its tests, the new lines are removed
from the diagnostic.

Unicode tables updated to both use the Unicode definitions
and the Unicode 14.0 data.

U+00AD SOFT HYPHEN is still considered a print character
to match existing practices in terminals, in addition of
being considered a formatting character as per Unicode.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D108469
2022-06-29 14:57:35 +02:00
Corentin Jabot a774ba7f60 Revert "Improve handling of static assert messages."
This reverts commit 870b6d2183.

This seems to break some libc++ tests, reverting while investigating
2022-06-29 00:03:23 +02:00
Corentin Jabot 870b6d2183 Improve handling of static assert messages.
Instead of dumping the string literal (which
quotes it and escape every non-ascii symbol),
we can use the content of the string when it is a
8 byte string.

Wide, UTF-8/UTF-16/32 strings are still completely
escaped, until we clarify how these entities should
behave (cf https://wg21.link/p2361).

`FormatDiagnostic` is modified to escape
non printable characters and invalid UTF-8.

This ensures that unicode characters, spaces and new
lines are properly rendered in static messages.
This make clang more consistent with other implementation
and fixes this tweet
https://twitter.com/jfbastien/status/1298307325443231744 :)

Of note, `PaddingChecker` did print out new lines that were
later removed by the diagnostic printing code.
To be consistent with its tests, the new lines are removed
from the diagnostic.

Unicode tables updated to both use the Unicode definitions
and the Unicode 14.0 data.

U+00AD SOFT HYPHEN is still considered a print character
to match existing practices in terminals, in addition of
being considered a formatting character as per Unicode.

Reviewed By: aaron.ballman, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D108469
2022-06-28 22:26:00 +02:00
Ben Langmuir eab2a06f0f Revert "Reland "[X86] Support `_Float16` on SSE2 and up""
Broke compiler-rt on Darwin: https://green.lab.llvm.org/green/job/clang-stage1-RA/29920/

This reverts commit 527ef8ca98.
2022-06-28 10:59:03 -07:00
Phoebe Wang 527ef8ca98 Reland "[X86] Support `_Float16` on SSE2 and up"
Enable `COMPILER_RT_HAS_FLOAT16` to solve the lit fail.

This is split from D113107 to address #56204 and https://discourse.llvm.org/t/how-to-build-compiler-rt-for-new-x86-half-float-abi/63366

Reviewed By: zahiraam, rjmccall, bkramer

Differential Revision: https://reviews.llvm.org/D128571
2022-06-28 14:38:56 +08:00
Vitaly Buka df18167ac5 [docs] Restore missing blank line
Lost in resolving conflicts for cdfa15da94.
2022-06-27 14:21:08 -07:00
Vitaly Buka cdfa15da94 Revert "[clang] Introduce -fstrict-flex-arrays=<n> for stricter handling of flexible arrays"
This reverts D126864 and related fixes.

This reverts commit 572b08790a.
This reverts commit 886715af96.
2022-06-27 14:03:09 -07:00
Vitaly Buka 8f7cca90af Revert "[X86] Support `_Float16` on SSE2 and up"
Breaks buildbot
https://lab.llvm.org/buildbot/#/builders/37/builds/14334

This reverts commit f5d781d627.
2022-06-27 12:43:29 -07:00
Chris Bieneman ee0dd2ec11 [Docs] Update clang & llvm release notes for HLSL
Adding release note entries for LLVM & Clang to introduce the HLSL &
DirectX support that is being added.

Reviewed By: aaron.ballman, MaskRay

Differential Revision: https://reviews.llvm.org/D127890
2022-06-27 12:41:14 -05:00
Phoebe Wang f5d781d627 [X86] Support `_Float16` on SSE2 and up
This is split from D113107 to address #56204 and https://discourse.llvm.org/t/how-to-build-compiler-rt-for-new-x86-half-float-abi/63366

Reviewed By: zahiraam, rjmccall, bkramer

Differential Revision: https://reviews.llvm.org/D128571
2022-06-27 21:37:30 +08:00
Stephen Long 186bea3750 [MSVC] Add initial support for MSVC pragma optimize
MSVC's pragma optimize turns optimizations on or off based on the list
passed. At the moment, we only support an empty optimization list.

i.e. `#pragma optimize("", on | off)`

From MSVC's docs:

| Parameter | Type of optimization                             |
|-----------|--------------------------------------------------|
| g         | Enable global optimizations. Deprecated          |
| s or t    | Specify short or fast sequences of machine code  |
| y         | Generate frame pointers on the program stack     |

https://docs.microsoft.com/en-us/cpp/preprocessor/optimize?view=msvc-170

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D125723
2022-06-24 08:03:42 -07:00
serge-sans-paille 886715af96 [clang] Introduce -fstrict-flex-arrays=<n> for stricter handling of flexible arrays
Some code [0] consider that trailing arrays are flexible, whatever their size.
Support for these legacy code has been introduced in
f8f6324983 but it prevents evaluation of
__builtin_object_size and __builtin_dynamic_object_size in some legit cases.

Introduce -fstrict-flex-arrays=<n> to have stricter conformance when it is
desirable.

n = 0: current behavior, any trailing array member is a flexible array. The default.
n = 1: any trailing array member of undefined, 0 or 1 size is a flexible array member
n = 2: any trailing array member of undefined or 0 size is a flexible array member
n = 3: any trailing array member of undefined size is a flexible array member (strict c99 conformance)

Similar patch for gcc discuss here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836

[0] https://docs.freebsd.org/en/books/developers-handbook/sockets/#sockets-essential-functions
2022-06-24 16:13:29 +02:00
Balázs Kéri 60f3b07118 [clang][analyzer] Add checker for bad use of 'errno'.
Extend checker 'ErrnoModeling' with a state of 'errno' to indicate
the importance of the 'errno' value and how it should be used.
Add a new checker 'ErrnoChecker' that observes use of 'errno' and
finds possible wrong uses, based on the "errno state".
The "errno state" should be set (together with value of 'errno')
by other checkers (that perform modeling of the given function)
in the future. Currently only a test function can set this value.
The new checker has no user-observable effect yet.

Reviewed By: martong, steakhal

Differential Revision: https://reviews.llvm.org/D122150
2022-06-20 10:07:31 +02:00
Roy Jacobson 21eb1af469 [Concepts] Implement overload resolution for destructors (P0848)
This patch implements a necessary part of P0848, the overload resolution for destructors.
It is now possible to overload destructors based on constraints, and the eligible destructor
will be selected at the end of the class.

The approach this patch takes is to perform the overload resolution in Sema::ActOnFields
and to mark the selected destructor using a new property in FunctionDeclBitfields.

CXXRecordDecl::getDestructor is then modified to use this property to return the correct
destructor.

This closes https://github.com/llvm/llvm-project/issues/45614.

Reviewed By: #clang-language-wg, erichkeane

Differential Revision: https://reviews.llvm.org/D126194
2022-06-19 00:30:37 +03:00
Jolanta Jensen c80c57674e [Clang] Allow 'Complex float __attribute__((mode(HC)))'
Adding half float to types that can be represented by __attribute__((mode(xx))).
Original implementation authored by George Steed.

Differential Revision: https://reviews.llvm.org/D126479
2022-06-17 12:39:52 +01:00
Javier Alvarez 5ea341d7c4 [clang] Fix trivially copyable for copy constructor and copy assignment operator
From [class.copy.ctor]:

```
A non-template constructor for class X is a copy constructor if its first
parameter is of type X&, const X&, volatile X& or const volatile X&, and
either there are no other parameters or else all other parameters have
default arguments (9.3.4.7).

A copy/move constructor for class X is trivial if it is not user-provided and if:
- class X has no virtual functions (11.7.3) and no virtual base classes (11.7.2), and
- the constructor selected to copy/move each direct base class subobject is trivial, and
- or each non-static data member of X that is of class type (or array thereof),
  the constructor selected to copy/move that member is trivial;

otherwise the copy/move constructor is non-trivial.
```

So `T(T&) = default`; should be trivial assuming that the previous
provisions are met.

This works in GCC, but not in Clang at the moment:
https://godbolt.org/z/fTGe71b6P

Reviewed By: royjacobson

Differential Revision: https://reviews.llvm.org/D127593
2022-06-17 10:35:01 +03:00
Mitch Phillips 011e0604eb Add DWARF string debug to clang release notes.
D12353 added inline strings to the DWARF info produced by clang. This
turns out to break some debugging software that assumes that a
DW_TAG_variable *must* come with a DW_AT_name. Add a release note to
broadcast this change.

Reviewed By: paulkirth

Differential Revision: https://reviews.llvm.org/D126224
2022-06-16 14:54:12 -07:00
Timm Bäder c149fa1f5f [clang][sema] Provide better diagnostic for missing template arguments
Instead of just complaining that "x is not a class, namespace or
enumeration", mention that using x requires template arguments.

Differential Revision: https://reviews.llvm.org/D127638

Fixes https://github.com/llvm/llvm-project/issues/55962
2022-06-15 16:06:06 +02:00
Martin Boehme 665da187cc [Clang] Add the `annotate_type` attribute
This is an analog to the `annotate` attribute but for types. The intent is to allow adding arbitrary annotations to types for use in static analysis tools.

For details, see this RFC:

https://discourse.llvm.org/t/rfc-new-attribute-annotate-type-iteration-2/61378

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D111548
2022-06-15 09:47:28 +02:00
Anders Waldenborg 657e954939 [clang] Add tests for statement expression in initializers
The commit 683e83c5
  [Clang][C++2b] P2242R3: Non-literal variables [...] in constexpr
fixed a code generation bug when using (C-extension) statement
expressions inside initializer expressions.

Before that commit a nested static initializer inside the statement
expression would not be emitted, causing it to be zero initialized.

It is a bit surprising (at least to me) that a commit implementing a new
C++ feature would fix this code generation bug. Zooming in it is the
change done in ExprConstant.cpp that helps. That changes so that
"ESR_Failed" is returned in more cases, causing the expression to not be
deemed constant. This fixes the code generation as instead the compiler
has to resort to generating a dynamic initializer.

That commit also meant that some statement expressions (in particular
the ones using static variables) that previously were accepted now are
errors due to not being constant (matching GCC behavior).

Given how a seemingly unrelated change caused this behavior to change,
it is probably a good thing to add at least some rudimentary tests for
these kind expressions.

Differential Revision: https://reviews.llvm.org/D127201
2022-06-14 23:16:41 +02:00
Shivam Gupta 48e1829874 [Diagnostics] Fix inconsistent shift-overflow warnings in C++20
This fixes https://github.com/llvm/llvm-project/issues/52873.
Don't warn in C++2A mode (and newer), as signed left shifts
always wrap and never overflow. Ref. -
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html.
2022-06-14 20:19:46 +05:30
Balazs Benics 9da697e1bc Reland "[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag"
It was previously reverted by 8406839d19.

---

This flag was introduced by
6818991d71
    commit 6818991d71
    Author: Ted Kremenek <kremenek@apple.com>
    Date:   Mon Dec 7 22:06:12 2009 +0000

  Add clang-cc option '-analyzer-opt-analyze-nested-blocks' to treat
  block literals as an entry point for analyzer checks.

The last reference was removed by this commit:
5c32dfc5fb

    commit 5c32dfc5fb
    Author: Anna Zaks <ganna@apple.com>
    Date:   Fri Dec 21 01:19:15 2012 +0000

  [analyzer] Add blocks and ObjC messages to the call graph.
  This paves the road for constructing a better function dependency graph.
  If we analyze a function before the functions it calls and inlines,
  there is more opportunity for optimization.
  Note, we add call edges to the called methods that correspond to
  function definitions (declarations with bodies).

Consequently, we should remove this dead flag.
However, this arises a couple of burning questions.
 - Should the `cc1` frontend still accept this flag - to keep
   tools/users passing this flag directly to `cc1` (which is unsupported,
   unadvertised) working.
 - If we should remain backward compatible, how long?
 - How can we get rid of deprecated and obsolete flags at some point?

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126067
2022-06-14 10:22:37 +02:00
Balazs Benics ffe7950ebc Reland "[analyzer] Deprecate `-analyzer-store region` flag"
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;

After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488

In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.

In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.

Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.

I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126215
2022-06-14 09:20:41 +02:00
Christopher Di Bella f21187eb2d [clang][tablegen] adds human documentation to `WarningOption`
Building on D126796, this commit adds the infrastructure for being able
to print out descriptions of what each warning does.

Differential Revision: https://reviews.llvm.org/D126832
2022-06-10 17:23:00 +00:00
Simon Tatham 9073b53e5d [Clang,ARM] Add release note for D127197.
I should have put that in the original commit, but @lenary only just
reminded me that it needed to be there.
2022-06-10 15:19:33 +01:00
Nico Weber 8406839d19 Revert "[analyzer] Deprecate `-analyzer-store region` flag"
This reverts commit d50d9946d1.
Broke check-clang, see comments on https://reviews.llvm.org/D126067

Also revert dependent change "[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag"
This reverts commit 07b4a6d046.

Also revert "[analyzer] Fix buildbots after introducing a new frontend warning"
This reverts commit 90374df15d.
(See https://reviews.llvm.org/rG90374df15ddc58d823ca42326a76f58e748f20eb)
2022-06-10 08:50:13 -04:00
Balazs Benics 07b4a6d046 [analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag
This flag was introduced by
6818991d71
    commit 6818991d71
    Author: Ted Kremenek <kremenek@apple.com>
    Date:   Mon Dec 7 22:06:12 2009 +0000

  Add clang-cc option '-analyzer-opt-analyze-nested-blocks' to treat
  block literals as an entry point for analyzer checks.

The last reference was removed by this commit:
5c32dfc5fb

    commit 5c32dfc5fb
    Author: Anna Zaks <ganna@apple.com>
    Date:   Fri Dec 21 01:19:15 2012 +0000

  [analyzer] Add blocks and ObjC messages to the call graph.
  This paves the road for constructing a better function dependency graph.
  If we analyze a function before the functions it calls and inlines,
  there is more opportunity for optimization.
  Note, we add call edges to the called methods that correspond to
  function definitions (declarations with bodies).

Consequently, we should remove this dead flag.
However, this arises a couple of burning questions.
 - Should the `cc1` frontend still accept this flag - to keep
   tools/users passing this flag directly to `cc1` (which is unsupported,
   unadvertised) working.
 - If we should remain backward compatible, how long?
 - How can we get rid of deprecated and obsolete flags at some point?

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126067
2022-06-10 13:09:37 +02:00
Balazs Benics d50d9946d1 [analyzer] Deprecate `-analyzer-store region` flag
I'm trying to remove unused options from the `Analyses.def` file, then
merge the rest of the useful options into the `AnalyzerOptions.def`.
Then make sure one can set these by an `-analyzer-config XXX=YYY` style
flag.
Then surface the `-analyzer-config` to the `clang` frontend;

After all of this, we can pursue the tablegen approach described
https://discourse.llvm.org/t/rfc-tablegen-clang-static-analyzer-engine-options-for-better-documentation/61488

In this patch, I'm proposing flag deprecations.
We should support deprecated analyzer flags for exactly one release. In
this case I'm planning to drop this flag in `clang-16`.

In the clang frontend, now we won't pass this option to the cc1
frontend, rather emit a warning diagnostic reminding the users about
this deprecated flag, which will be turned into error in clang-16.

Unfortunately, I had to remove all the tests referring to this flag,
causing a mass change. I've also added a test for checking this warning.

I've seen that `scan-build` also uses this flag, but I think we should
remove that part only after we turn this into a hard error.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D126215
2022-06-10 12:57:15 +02:00
Matthias Gehre 7e17e15c9f clang: Introduce -fexperimental-max-bitint-width
This splits of the introduction of -fexperimental-max-bitint-width
from https://reviews.llvm.org/D122234
because that PR is still blocked on discussions on the backend side.

I was asked [0] to upstream at least the flag.

[0] 09854f2af3 (commitcomment-75116619)

Differential Revision: https://reviews.llvm.org/D127287
2022-06-09 07:15:03 +01:00
Andrew Browne c7689fd552 [Clang] Fix memory leak due to TemplateArgumentListInfo used in AST node.
It looks like the leak is rooted at the allocation here:
1a155ee7de/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp (L3857)

The VarTemplateSpecializationDecl is allocated using placement new which uses the AST structure for ownership: 1a155ee7de/clang/lib/AST/DeclBase.cpp (L99)

The problem is the TemplateArgumentListInfo inside 1a155ee7de/clang/include/clang/AST/DeclTemplate.h (L2721)
This object contains a vector which does not use placement new: 1a155ee7de/clang/include/clang/AST/TemplateBase.h (L564)

Apparently ASTTemplateArgumentListInfo should be used instead 1a155ee7de/clang/include/clang/AST/TemplateBase.h (L575)

https://reviews.llvm.org/D125802#3551305

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D126944
2022-06-08 09:58:25 -07:00
Martin Storsjö 20ca739701 [doc] Add release notes about SEH unwind information on ARM
Differential Revision: https://reviews.llvm.org/D127150
2022-06-08 11:32:17 +03:00
Evgeny Shulgin a4f8590247 [clang] Allow consteval functions in default arguments
We should not mark a function as "referenced" if we call it within a
ConstantExpr, because the expression will be folded to a value in LLVM
IR. To prevent emitting consteval function declarations, we should not "jump
over" a ConstantExpr when it is a top-level ParmVarDecl's subexpression.

Fixes https://github.com/llvm/llvm-project/issues/48230

Reviewed By: erichkeane, aaron.ballman, ChuanqiXu

Differenitial Revision: https://reviews.llvm.org/D119646
2022-06-07 10:54:37 +08:00
Aaron Ballman 881125ad91 Allow use of an elaborated type specifier in a _Generic association in C++
Currently, Clang accepts this code in C mode (where the tag is required
to be used) but rejects it in C++ mode thinking that the association is
defining a new type.

void foo(void) {
  struct S { int a; };
  _Generic(something, struct S : 1);
}
Clang thinks this in C++ because it sees struct S : when parsing the
class specifier and decides that must be a type definition (because the
colon signifies the presence of a base class type). This patch adds a
new declarator context to represent a _Generic association so that we
can distinguish these situations properly.

Fixes #55562

Differential Revision: https://reviews.llvm.org/D126969
2022-06-06 07:17:35 -04:00
Anders Waldenborg dd2362a8ba [clang] Allow const variables with weak attribute to be overridden
A variable with `weak` attribute signifies that it can be replaced with
a "strong" symbol link time. Therefore it must not emitted with
"weak_odr" linkage, as that allows the backend to use its value in
optimizations.

The frontend already considers weak const variables as
non-constant (note_constexpr_var_init_weak diagnostic) so this change
makes frontend and backend consistent.

This commit reverses the
  f49573d1 weak globals that are const should get weak_odr linkage.
commit from 2009-08-05 which introduced this behavior. Unfortunately
that commit doesn't provide any details on why the change was made.

This was discussed in
https://discourse.llvm.org/t/weak-attribute-semantics-on-const-variables/62311

Differential Revision: https://reviews.llvm.org/D126324
2022-06-03 23:44:15 +02:00
Akira Hatanaka b64f6e5722 Add a release note for the scope enum initialization bug fix in
https://reviews.llvm.org/D126084
2022-06-02 17:13:05 -07:00
Aaron Ballman c745f2ce6c Revert "Drop qualifiers from return types in C (DR423)"
This reverts commit d374b65f2d.

The changes lose AST fidelity (reported in #55778), but also may be
improperly dropping _Atomic qualifiers. I am rolling the changes back
until I've finished discussions in WG14 about the proper resolution to
DR423.
2022-06-02 08:28:43 -04:00
Mital Ashok 872f74440f Fix std::has_unique_object_representations for _BitInt types with padding bits
"std::has_unique_object_representations<_BitInt(N)>" was always true,
even if the type has padding bits (since the trait assumes all integer
types have no padding bits). The standard has an explicit note that
this should not hold for types with padding bits.

Differential Revision: https://reviews.llvm.org/D125802
2022-06-01 11:34:40 -04:00
Luke Nihlen 1f6ea2a37c Expand definition deprecation warning to include constexpr statements.
Clang currently warns on definitions downgraded to declarations
with a const modifier, but not for a constexpr modifier. This patch
updates the warning logic to warn on both inputs, and adds a test to
check the additional case as well.

See also: https://bugs.chromium.org/p/chromium/issues/detail?id=1284718

Differential Revision: https://reviews.llvm.org/D126664
2022-06-01 11:31:07 -04:00
Phoebe Wang a2ea5b496b [X86] Add support for `-mharden-sls=[none|all|return|indirect-jmp]`
The patch addresses the feature request from https://github.com/ClangBuiltLinux/linux/issues/1633. The implementation borrows a lot from aarch64.

Reviewed By: nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D126137
2022-06-01 09:45:04 +08:00
James Y Knight 997b072e10 C++ DR2394: Const-default-constructible for members.
Const class members may be initialized with a defaulted default
constructor under the same conditions it would be allowed for a const
object elsewhere.

Differential Revision: https://reviews.llvm.org/D126170
2022-05-25 14:20:11 -04:00
David Blaikie e59f648d69 Move GCC-compatible pod-packing change to v15/old behavior available at v14 and below
Since this didn't make it into the v14 release - anyone requesting the
v14 ABI shouldn't get this GCC-compatible change that isn't backwards
compatible with v14 Clang.

Differential Revision: https://reviews.llvm.org/D126334
2022-05-25 03:03:27 +00:00
Chuanqi Xu a1ffba8d52 [C++20] [Coroutines] Conform the updates for CWG issue 2585
According to the updates in CWG issue 2585
https://cplusplus.github.io/CWG/issues/2585.html, we shouldn't find an
allocation function with (size, p0, …, pn) in global scope.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D126187
2022-05-25 10:31:26 +08:00
David Blaikie 0b903ef6aa Re-add release notes for GCC ABI compatibility for non-POD in packed structs 2022-05-22 01:15:34 +00:00
Stephen Long ae80024fbe [clang] Honor __attribute__((no_builtin("foo"))) on functions
Support for `__attribute__((no_builtin("foo")))` was added in https://reviews.llvm.org/D68028,
but builtins were still being used even when the attribute was placed on a function.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D124701
2022-05-20 06:41:47 -07:00
Aaron Ballman d374b65f2d Drop qualifiers from return types in C (DR423)
WG14 DR423 (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2148.htm#dr_423),
resolved during the C11 time frame, changed the way qualifiers are
handled on function return types and in cast expressions after it was
noted that these types are now directly observable via generic
selection expressions. In C, the function declarator is adjusted to
ignore all qualifiers (including _Atomic qualifiers).

Clang already handles the cast expression case correctly (by performing
the lvalue conversion, which drops the qualifiers as well), but with
these changes it will now also handle function declarations
appropriately.

Fixes #39595

Differential Revision: https://reviews.llvm.org/D125919
2022-05-19 13:06:50 -04:00
Archibald Elliott 2321c36fbf [ARM] Don't Enable AES Pass for Generic Cores
This brings clang/llvm into line with GCC. The Pass is still enabled for
the affected cores, but is now opt-in when using `-march=`.

I also took the opportunity to add release notes for this change.

Reviewed By: john.brawn

Differential Revision: https://reviews.llvm.org/D125775
2022-05-18 13:10:31 +01:00
Gabor Marton 56b9b97c1e [clang][analyzer][ctu] Make CTU a two phase analysis
This new CTU implementation is the natural extension of the normal single TU
analysis. The approach consists of two analysis phases. During the first phase,
we do a normal single TU analysis. During this phase, if we find a foreign
function (that could be inlined from another TU) then we don’t inline that
immediately, we rather mark that to be analysed later.
When the first phase is finished then we start the second phase, the CTU phase.
In this phase, we continue the analysis from that point (exploded node)
which had been enqueued during the first phase. We gradually extend the
exploded graph of the single TU analysis with the new node that was
created by the inlining of the foreign function.

We count the number of analysis steps of the first phase and we limit the
second (ctu) phase with this number.

This new implementation makes it convenient for the users to run the
single-TU and the CTU analysis in one go, they don't need to run the two
analysis separately. Thus, we name this new implementation as "onego" CTU.

Discussion:
https://discourse.llvm.org/t/rfc-much-faster-cross-translation-unit-ctu-analysis-implementation/61728

Differential Revision: https://reviews.llvm.org/D123773
2022-05-18 10:35:52 +02:00
Erich Keane 2def74bef1 Fix release note typo from 6da3d66f 2022-05-17 06:35:06 -07:00
Erich Keane 6da3d66f03 [concepts] Implement dcl.decl.general p4: No constraints on non-template funcs
The standard says:
The optional requires-clause ([temp.pre]) in an init-declarator or
member-declarator shall be present only if the declarator declares a
templated function ([dcl.fct]).

This implements that limitation, and updates the tests to the best of my
ability to capture the intent of the original checks.

Differential Revision: https://reviews.llvm.org/D125711
2022-05-17 06:21:51 -07:00
Chuanqi Xu 452fac9534 [Frontend] [Coroutines] Emit error when we found incompatible allocation
function in promise_type

According to https://cplusplus.github.io/CWG/issues/2585.html, this
fixes https://github.com/llvm/llvm-project/issues/54881

Simply, the clang tried to found (do lookup and overload resolution. Is
there any better word to use than found?) allocation function in
promise_type and global scope. However, this is not consistent with the
standard. The standard behavior would be that the compiler shouldn't
lookup in global scope in case we lookup the allocation function name in
promise_type. In other words, the program is ill-formed if there is
incompatible allocation function in promise type.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D125517
2022-05-17 10:36:21 +08:00
Stephen Long b147717bb3 [MSVC] Add support for pragma alloc_text
`#pragma alloc_text` is a MSVC pragma that names the code section where functions should be placed. It only
applies to functions with C linkage.

https://docs.microsoft.com/en-us/cpp/preprocessor/alloc-text?view=msvc-170

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D125011
2022-05-16 07:00:17 -07:00
Stephen Long 3946de0456 [MSVC] Add support for pragma function
MSVC pragma function tells the compiler to generate calls to functions in the pragma function list, instead of using the builtin. Needs https://reviews.llvm.org/D124701

https://docs.microsoft.com/en-us/cpp/preprocessor/function-c-cpp?view=msvc-170

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D124702
2022-05-13 06:39:47 -07:00
Ken Matsui a247ba9d15 Suggest typo corrections for preprocessor directives
When a preprocessor directive is unknown outside of a skipped
conditional block, we give an error diagnostic because we don't know
how to proceed with preprocessing. But when the directive is in a
skipped conditional block, we would not diagnose it on the theory that
the directive may be known to an implementation other than Clang.

Now, for unknown directives inside a skipped conditional block, we
diagnose the unknown directive as a warning if it is sufficiently
similar to a directive specific to preprocessor conditional blocks. For
example, we'll warn about `#esle` and suggest `#else` but we won't warn
about `#progma` because it's not a directive specific to preprocessor
conditional blocks.

Fixes #51598

Differential Revision: https://reviews.llvm.org/D124726
2022-05-13 09:16:46 -04:00
Whisperity 9add949557 [ASTMatchers][clang-tidy][NFC] Hoist `forEachTemplateArgument` matcher into the core library
Fixes the `FIXME:` related to adding `forEachTemplateArgument` to the
core AST Matchers library.

Reviewed By: aaron.ballman

Differential Revision: http://reviews.llvm.org/D125383
2022-05-13 12:55:48 +02:00
Timm Bäder b91073db6a [clang][preprocessor] Fix unsigned-ness of utf8 char literals
UTF8 char literals are always unsigned.

Fixes https://github.com/llvm/llvm-project/issues/54886

Differential Revision: https://reviews.llvm.org/D124996
2022-05-13 07:57:10 +02:00
Aaron Ballman c671041720 Check for resource exhaustion when recursively parsing declarators
With sufficiently tortured code, it's possible to cause a stack
overflow when parsing declarators. Thus, we now check for resource
exhaustion when recursively parsing declarators so that we can at least
warn the user we're about to crash before we actually crash.

Fixes #51642

Differential Revision: https://reviews.llvm.org/D124915
2022-05-12 13:20:35 -04:00
Ken Matsui a1545f51a9 Warn if using `elifdef` & `elifndef` in not C2x & C++2b mode
This adds an extension warning when using the preprocessor conditionals
in a language mode they're not officially supported in, and an opt-in
warning for compatibility with previous standards.

Fixes #55306
Differential Revision: https://reviews.llvm.org/D125178
2022-05-12 09:26:44 -04:00
David Tenty d9c1d3cbcb [clang][AIX] Don't ignore XCOFF visibility by default
D87451 added -mignore-xcoff-visibility for AIX targets and made it the default (which mimicked the behaviour of the XL 16.1 compiler on AIX).

However, ignoring hidden visibility has unwanted side effects and some libraries depend on visibility to hide non-ABI facing entities from user headers and
reserve the right to change these implementation details based on this (https://libcxx.llvm.org/DesignDocs/VisibilityMacros.html). This forces us to use
internal linkage fallbacks for these cases on AIX and creates an unwanted divergence in implementations on the plaform.

For these reasons, it's preferable to not add -mignore-xcoff-visibility by default, which is what this patch does.

Reviewed By: DiggerLin

Differential Revision: https://reviews.llvm.org/D125141
2022-05-11 13:27:48 -04:00
Ken Matsui 786c721c2b Add extension diagnostic for linemarker directives
This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu,
to warn about use of the GNU linemarker preprocessor extension.

Fixes #55067

Differential Revision: https://reviews.llvm.org/D124534
2022-05-11 06:42:00 -04:00
Yaxun (Sam) Liu 180a8536ce Fix indentation in ReleaseNotes.rst 2022-05-10 14:56:28 -04:00
Yaxun (Sam) Liu afc9d674fe [CUDA][HIP] support __noinline__ as keyword
CUDA/HIP programs use __noinline__ like a keyword e.g.
__noinline__ void foo() {} since __noinline__ is defined
as a macro __attribute__((noinline)) in CUDA/HIP runtime
header files.

However, gcc and clang supports __attribute__((__noinline__))
the same as __attribute__((noinline)). Some C++ libraries
use __attribute__((__noinline__)) in their header files.
When CUDA/HIP programs include such header files,
clang will emit error about invalid attributes.

This patch fixes this issue by supporting __noinline__ as
a keyword, so that CUDA/HIP runtime could remove
the macro definition.

Reviewed by: Aaron Ballman, Artem Belevich

Differential Revision: https://reviews.llvm.org/D124866
2022-05-10 14:32:27 -04:00
Aaron Ballman ca75ac5f04 Diagnose unreachable generic selection associations
The controlling expression of a _Generic selection expression undergoes
lvalue conversion, array conversion, and function conversion before
picking the association. This means that array types, function types,
and qualified types are all unreachable code if they're used as an
association. I've been caught by this twice in the past few months and
I figure that if a WG14 member can't seem to remember this rule, users
are also likely to struggle with it. So this adds an on-by-default
unreachable code diagnostic for generic selection expression
associations.

Note, we don't have to worry about function types as those are already
a constraint violation which generates an error.

Differential Revision: https://reviews.llvm.org/D125259
2022-05-10 11:15:56 -04:00
Erich Keane 017abbb258 Revert ""Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""""
This reverts commit a425cac31e.

There is another libc++ test, that this time causes us to hit an
assertion. Reverting, likely for a while this time.
2022-05-09 09:12:05 -07:00
Micah Weston 882915df61 Enum conversion warning when one signed and other unsigned.
Ensures an -Wenum-conversion warning happens when one of the enums is
signed and the other is unsigned. Also adds a test file to verify these
warnings.

This warning would not happen since the -Wsign-conversion would make a
diagnostic then return, never allowing the -Wenum-conversion checks.

For example:

C
enum PE { P = -1 };
enum NE { N };
enum NE conv(enum PE E) { return E; }
Before this would only create a diagnostic with -Wsign-conversion and
never on -Wenum-conversion. Now it will create a diagnostic for both
-Wsign-conversion and -Wenum-conversion.

I could change it to just warn on -Wenum-conversion as that was what I
initially did. Seeing PR35200 (or GitHub Issue 316268), I let both
diagnostics check so that the sign conversion could generate a warning.
2022-05-09 10:16:19 -04:00
Aaron Puchert 44ae49e1a7 Thread safety analysis: Handle compound assignment and ->* overloads
Like regular assignment, compound assignment operators can be assumed to
write to their left-hand side operand. So we strengthen the requirements
there. (Previously only the default read access had been required.)

Just like operator->, operator->* can also be assumed to dereference the
left-hand side argument, so we require read access to the pointee. This
will generate new warnings if the left-hand side has a pt_guarded_by
attribute. This overload is rarely used, but it was trivial to add, so
why not. (Supporting the builtin operator requires changes to the TIL.)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D124966
2022-05-09 15:35:43 +02:00
Erich Keane a425cac31e "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""""
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.

This reverts commit 45c07db31c.
2022-05-09 06:29:47 -07:00
Shivam bbd031943a
Update ReleaseNotes.rst 2022-05-07 01:20:45 +05:30