[clang][AIX] Add option to control quadword lock free atomics ABI on AIX

We are supporting quadword lock free atomics on AIX. For the situation that users on AIX are using a libatomic that is lock-b

[clang][AIX] Add option to control quadword lock free atomics ABI on AIX

We are supporting quadword lock free atomics on AIX. For the situation that users on AIX are using a libatomic that is lock-based for quadword types, we can't enable quadword lock free atomics by default on AIX in case user's new code and existing code accessing the same shared atomic quadword variable, we can't guarentee atomicity. So we need an option to enable quadword lock free atomics on AIX, thus we can build a quadword lock-free libatomic(also for advanced users considering atomic performance critical) for users to make the transition smooth.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D127189

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[clang] Use value instead of getValue (NFC)

[X86] initial -mfunction-return=thunk-extern support

Adds support for:
* `-mfunction-return=<value>` command line flag, and
* `__attribute__((function_return("<value>")))` function attribute

Where

[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

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[clang] Don't use Optional::hasValue (NFC)

This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.

Revert "Don't use Optional::hasValue (NFC)"

This reverts commit aa8feeefd3ac6c78ee8f67bf033976fc7d68bc6d.

Don't use Optional::hasValue (NFC)

Revert "DebugInfo: Fully integrate ctor type homing into 'limited' debug info"

Reverting to simplify some Google-internal rollout issues. Will recommit
in a week or two.

This reverts commit 517bbc6

Revert "DebugInfo: Fully integrate ctor type homing into 'limited' debug info"

Reverting to simplify some Google-internal rollout issues. Will recommit
in a week or two.

This reverts commit 517bbc64dbe493644eff8d55fd9566435e930520.

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DebugInfo: Fully integrate ctor type homing into 'limited' debug info

Simplify debug info back to just "limited" or "full" by rolling the ctor
type homing fully into the "limited" debug info.

Also

DebugInfo: Fully integrate ctor type homing into 'limited' debug info

Simplify debug info back to just "limited" or "full" by rolling the ctor
type homing fully into the "limited" debug info.

Also fix a bug I found along the way that was causing ctor type homing
to kick in even when something could be vtable homed (where vtable
homing is stronger/more effective than ctor homing) - fixing at the same
time as it keeps the tests (that were testing only "limited non ctor"
homing and now test ctor homing) passing.

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[clang] Don't use Optional::getValue (NFC)

[clang] Use value_or instead of getValueOr (NFC)

[analyzer][NFC] Replace getLastArg with hasArg when applicable

Depends on D126215.

Reland "[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag"

It was previously reverted by 8406839d1926486de900c7cabeea9f841bd3edf2.

---

This flag was introduced by
https

Reland "[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag"

It was previously reverted by 8406839d1926486de900c7cabeea9f841bd3edf2.

---

This flag was introduced by
https://github.com/llvm/llvm-project/commit/6818991d7165f68fe196922d9e5c6648dd57cc47
commit 6818991d7165f68fe196922d9e5c6648dd57cc47
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:
https://github.com/llvm/llvm-project/commit/5c32dfc5fb1cfcff8ae3671284e17daa8da3a188

commit 5c32dfc5fb1cfcff8ae3671284e17daa8da3a188
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

show more ...

[analyzer][NFC] Inline AnalyzerOptions::getUserMode()

When I read the code I found it easier to reason about if `getUserMode`
is inlined. It might be a personal preference though.

Reviewed By: mart

[analyzer][NFC] Inline AnalyzerOptions::getUserMode()

When I read the code I found it easier to reason about if `getUserMode`
is inlined. It might be a personal preference though.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D127486

show more ...

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`

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

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Revert "[analyzer] Deprecate `-analyzer-store region` flag"

This reverts commit d50d9946d1d7e5f20881f0bc71fbd025040b1c96.
Broke check-clang, see comments on https://reviews.llvm.org/D126067

Also re

Revert "[analyzer] Deprecate `-analyzer-store region` flag"

This reverts commit d50d9946d1d7e5f20881f0bc71fbd025040b1c96.
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 07b4a6d0461fe64e10d30029ed3d598e49ca3810.

Also revert "[analyzer] Fix buildbots after introducing a new frontend warning"
This reverts commit 90374df15ddc58d823ca42326a76f58e748f20eb.
(See https://reviews.llvm.org/rG90374df15ddc58d823ca42326a76f58e748f20eb)

show more ...

[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag

This flag was introduced by
https://github.com/llvm/llvm-project/commit/6818991d7165f68fe196922d9e5c6648dd57cc47
com

[analyzer] Deprecate the unused 'analyzer-opt-analyze-nested-blocks' cc1 flag

This flag was introduced by
https://github.com/llvm/llvm-project/commit/6818991d7165f68fe196922d9e5c6648dd57cc47
commit 6818991d7165f68fe196922d9e5c6648dd57cc47
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:
https://github.com/llvm/llvm-project/commit/5c32dfc5fb1cfcff8ae3671284e17daa8da3a188

commit 5c32dfc5fb1cfcff8ae3671284e17daa8da3a188
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

show more ...

[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 ma

[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

show more ...

[HLSL] Enable vector types for hlsl.

Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.

[HLSL] Enable vector types for hlsl.

Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D125052

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Revert "[HLSL] Enable vector types for hlsl."

This reverts commit e576280380d3f5221cfcc14e9fabeacc8506a43c.
Breaks tests on mac/arm, see comment on https://reviews.llvm.org/D125052

Also revert foll

Revert "[HLSL] Enable vector types for hlsl."

This reverts commit e576280380d3f5221cfcc14e9fabeacc8506a43c.
Breaks tests on mac/arm, see comment on https://reviews.llvm.org/D125052

Also revert follow-up "[gn build] Port e576280380d3"
This reverts commit 1e01b1ec72031fcaceb4e77e1c5c8e34f1e862e8.

show more ...

[HLSL] Enable vector types for hlsl.

Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.

[HLSL] Enable vector types for hlsl.

Vector types in hlsl is using clang ext_vector_type.
Declaration of vector types is in builtin header hlsl.h.
hlsl.h will be included by default for hlsl shader.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D125052

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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

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

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[clang] Add the flag -ffile-reproducible

When Clang generates the path prefix (i.e. the path of the directory
where the file is) when generating FILE, __builtin_FILE(), and
std::source_location, Cla

[clang] Add the flag -ffile-reproducible

When Clang generates the path prefix (i.e. the path of the directory
where the file is) when generating FILE, __builtin_FILE(), and
std::source_location, Clang uses the platform-specific path separator
character of the build environment where Clang _itself_ is built. This
leads to inconsistencies in Chrome builds where Clang running on
non-Windows environments uses the forward slash (/) path separator
while Clang running on Windows builds uses the backslash (\) path
separator. To fix this, we add a flag -ffile-reproducible (and its
inverse, -fno-file-reproducible) to have Clang use the target's
platform-specific file separator character.

Additionally, the existing flags -fmacro-prefix-map and
-ffile-prefix-map now both imply -ffile-reproducible. This can be
overriden by setting -fno-file-reproducible.

[0]: https://crbug.com/1310767

Differential revision: https://reviews.llvm.org/D122766

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[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).

H

[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

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Mark identifier prefixes as substitutable

The Itanium C++ ABI says prefixes are substitutable. For most prefixes
we already handle this: the manglePrefix(const DeclContext *, bool) and
manglePrefix(

Mark identifier prefixes as substitutable

The Itanium C++ ABI says prefixes are substitutable. For most prefixes
we already handle this: the manglePrefix(const DeclContext *, bool) and
manglePrefix(QualType) overloads explicitly handles substitutions or
defer to functions that handle substitutions on their behalf. The
manglePrefix(NestedNameSpecifier *) overload, however, is different and
handles some cases implicitly, but not all. The Identifier case was not
handled; this change adds handling for it, as well as a test case.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D122663

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Additionally set f32 mode with denormal-fp-math

When the denormal-fp-math option is used, this should set the
denormal handling mode for all floating point types. However,
currently 32-bit float typ

Additionally set f32 mode with denormal-fp-math

When the denormal-fp-math option is used, this should set the
denormal handling mode for all floating point types. However,
currently 32-bit float types can ignore this setting as there is a
variant of the option, denormal-fp-math-f32, specifically for that type
which takes priority when checking the mode based on type and remains
at the default of IEEE. From the description, denormal-fp-math would
be expected to set the mode for floats unless overridden by the f32
variant, and code in the front end only emits the f32 option if it is
different to the general one, so setting just denormal-fp-math should
be valid.

This patch changes the denormal-fp-math option to also set the f32
mode. If denormal-fp-math-f32 is also specified, this is then
overridden as expected, but if it is absent floats will be set to the
mode specified by the former option, rather than remain on the default.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D122589

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