Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.

- AMDGPU uses the fp32-denormals and fp64-f16-denormals subtarget features
- NVPTX uses the nvptx-f32ftz attribute
- ARM directly uses the denormal-fp-math attribute
- Other targets indirectly use denormal-fp-math in one DAGCombine
- cl-denorms-are-zero has a corresponding denorms-are-zero attribute

AMDGPU wants a distinct control for f32 flushing from f16/f64, and as
far as I can tell the same is true for NVPTX (based on the attribute
name).

Work on consolidating these into the denormal-fp-math attribute, and a
new type specific denormal-fp-math-f32 variant. Only ARM seems to
support the two different flush modes, so this is overkill for the
other use cases. Ideally we would error on the unsupported
positive-zero mode on other targets from somewhere.

Move the logic for selecting the flush mode into the compiler driver,
instead of handling it in cc1. denormal-fp-math/denormal-fp-math-f32
are now both cc1 flags, but denormal-fp-math-f32 is not yet exposed as
a user flag.

-cl-denorms-are-zero, -fcuda-flush-denormals-to-zero and
-fno-cuda-flush-denormals-to-zero will be mapped to
-fp-denormal-math-f32=ieee or preserve-sign rather than the old
attributes.

Stop emitting the denorms-are-zero attribute for the OpenCL flag. It
has no in-tree users. The meaning would also be target dependent, such
as the AMDGPU choice to treat this as only meaning allow flushing of
f32 and not f16 or f64. The naming is also potentially confusing,
since DAZ in other contexts refers to instructions implicitly treating
input denormals as zero, not necessarily flushing output denormals to
zero.

This also does not attempt to change the behavior for the current
attribute. The LangRef now states that the default is ieee behavior,
but this is inaccurate for the current implementation. The clang
handling is slightly hacky to avoid touching the existing
denormal-fp-math uses. Fixing this will be left for a future patch.

AMDGPU is still using the subtarget feature to control the denormal
mode, but the new attribute are now emitted. A future change will
switch this and remove the subtarget features.

A TemplateIdAnnotation represents only a template-id, not a
nested-name-specifier plus a template-id. Don't make a redundant copy of
the CXXScopeSpec and store it on the template-id annotation.

This slightly improves error recovery by more properly handling the case
where we would form an invalid CXXScopeSpec while parsing a typename
specifier, instead of accidentally putting the token stream into a
broken "annot_template_id with a scope specifier, but with no preceding
annot_cxxscope token" state.

This is an alternative to the continous mode that was implemented in
D68351. This mode relies on padding and the ability to mmap a file over
the existing mapping which is generally only available on POSIX systems
and isn't suitable for other platforms.

This change instead introduces the ability to relocate counters at
runtime using a level of indirection. On every counter access, we add a
bias to the counter address. This bias is stored in a symbol that's
provided by the profile runtime and is initially set to zero, meaning no
relocation. The runtime can mmap the profile into memory at abitrary
location, and set bias to the offset between the original and the new
counter location, at which point every subsequent counter access will be
to the new location, which allows updating profile directly akin to the
continous mode.

The advantage of this implementation is that doesn't require any special
OS support. The disadvantage is the extra overhead due to additional
instructions required for each counter access (overhead both in terms of
binary size and performance) plus duplication of counters (i.e. one copy
in the binary itself and another copy that's mmapped).

Differential Revision: https://reviews.llvm.org/D69740

Summary: Depends on D72847

Reviewers: vvereschaka, aorlov, andreil99

Reviewed By: vvereschaka

Subscribers: mgorny, kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72850

Extend -fxray-instrumentation-bundle to split function-entry and
function-exit into two separate options, so that it is possible to
instrument only function entry or only function exit.  For use cases
that only care about one or the other this will save significant overhead
and code size.

Differential Revision: https://reviews.llvm.org/D72890

XRay allows tuning by minimum function size, but also always instruments
functions with loops in them. If the minimum function size is set to a
large value the loop instrumention ends up causing most functions to be
instrumented anyway. This adds a new flag, -fxray-ignore-loops, to disable
the loop detection logic.

Differential Revision: https://reviews.llvm.org/D72873

[this re-applies c0176916
 with the correct commit message and phabricator link]

This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213

The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.

This should have no effect on DWARF consumers other than LLDB.

Differential Revision: https://reviews.llvm.org/D71732

This reverts commit 12e47947.

I accidentally landed this patch with the wrong commit message ...

Emit more precise debug locations for the OpenMP outlined regions.

llvm-nm on Linux prints 0 line while llvm-nm on macOS prints 1 line.

Summary:
When compiling with -munwind-tables, the SEH filter funclet needs the uwtable
function attribute, which gets automatically added if we use
SetInternalFunctionAttributes.  The filter funclet is internal so this seems
appropriate.

Reviewers: rnk

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72786

After D69825, the output of clang -### when running in process can be
prefixed by ' (in-process)'. Skip it.

This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.

This attribute only appears in Clang module debug info.

Differential Revision: https://reviews.llvm.org/D71722

Summary: Currently, an attempt to rewrite source code inside a macro expansion succeeds, but results in empty text, rather than failing with an error.  This patch restructures to the code to explicitly validate ranges before attempting to edit them.

Reviewers: gribozavr

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72274

RecursiveASTVisitor expects TraverseDecl to be implemented by
subclasses.

Right now every dataflow algorithm uses its own worklist implementation.
This is a first step to reduce this duplication. Some upcoming
algorithms such as the lifetime analysis is going to use the factored
out implementations.

Differential Revision: https://reviews.llvm.org/D72380

Summary:
tslint and tsc (the TypeScript compiler itself) use comment pragmas of
the style:

  // tslint:disable-next-line:foo
  // @ts-ignore

These must not be wrapped and must stay on their own line, in isolation.
For tslint, this required adding it to the pragma regexp. The comments
starting with `@` are already left alone, but this change adds test
coverage for them.

Reviewers: krasimir

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72907

Summary:
Revision a75f8d98 fixed spacing for operators,
but caused the const and non-const versions to diverge:
```
// With Style.PointerAlignment = FormatStyle::PAS_Left:

struct A {
  operator char*() { return ""; }
  operator const char *() const { return ""; }
};

```
The code was checking if the type specifier was directly preceded by `operator`.
However there could be comments and `const/volatile` in between.

Reviewers: mprobst

Reviewed By: mprobst

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72911

Summary:
Including `do`, `for`, and `while`, `if`, `else`, `try`, `catch`, in
addition to the previously handled fields. The unit test explicitly uses
methods, but this code path handles both fields and methods.

Reviewers: krasimir

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72827

Glibc issue: https://sourceware.org/bugzilla/show_bug.cgi?id=25399
The fix consist in considering the missing function as a builtin lowered to a nop.

Differential Revision: https://reviews.llvm.org/D72869

This reverts commit 3d210ed3.

See https://reviews.llvm.org/D71082 for the patch and discussion that make it
possible to reapply this patch.

Partially reverts 0a2be46c as it turned
out to cause redundant module rebuilds in multi-process incremental builds.
When a module was getting out of date, all compilation processes started at the
same time were marking it as `ToBuild`. So each process was building the same
module instead of checking if it was built by someone else and using that
result. In addition to the work duplication, contention on the same .pcm file
wasn't making builds faster.

Note that for a single-process build this change would cause redundant module
reads and validations. But reading a module is faster than building it and
multi-process builds are more common than single-process. So I'm willing to
make such a trade-off.

rdar://problem/54395127

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D72860

When LLVM_APPEND_VC_REV=OFF is set, the current git hash is no
longer embedded into binaries (mostly for --version output).
Without it, most binaries need to relink after every single
commit, even if they didn't change otherwise (due to, say,
a documentation-only commit).

LLVM_APPEND_VC_REV is ON by default, so this doesn't change the
default behavior of anything.

With this, all clients of GenerateVersionFromVCS.cmake honor
LLVM_APPEND_VC_REV.

Differential Revision: https://reviews.llvm.org/D72855

PointerLikeTypeTraits: Standardize NumLowBitsAvailable on static constexpr rather than anonymous enum

This is (more?) usable by GDB pretty printers and seems nicer to write.

There's one tricky caveat that in C++14 (LLVM's codebase today) the
static constexpr member declaration is not a definition - so odr use of
this constant requires an out of line definition, which won't be
provided (that'd make all these trait classes more annoyidng/expensive
to maintain). But the use of this constant in the library implementation
is/should always be in a non-odr context - only two unit tests needed to
be touched to cope with this/avoid odr using these constants.

Based on/expanded from D72590 by Christian Sigg.

Need to disable emission of RTTI descriptors for NVPTX devices to be
able to use dynamic classes without unresolved symbols at link stage.

generation function, NFC.

In addition to that, use target features to validate intrinsic
availability on a given target.

Use floating-point instead of integer zero constants to avoid
creating implicit conversions, which currently cause suboptimal
code to be generated with -ffp-exception-behavior=strict.

NFC otherwise.

Summary:
The old pass manager separated speed optimization and size optimization
levels into two unsigned values. Coallescing both in an enum in the new
pass manager may lead to unintentional casts and comparisons.

In particular, taking a look at how the loop unroll passes were constructed
previously, the Os/Oz are now (==new pass manager) treated just like O3,
likely unintentionally.

This change disallows raw comparisons between optimization levels, to
avoid such unintended effects. As an effect, the O{s|z} behavior changes
for loop unrolling and loop unroll and jam, matching O2 rather than O3.

The change also parameterizes the threshold values used for loop
unrolling, primarily to aid testing.

Reviewers: tejohnson, davidxl

Reviewed By: tejohnson

Subscribers: zzheng, ychen, mehdi_amini, hiraditya, steven_wu, dexonsmith, dang, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72547

$URL$ is an SVN keyword substitution enabled via
`svn propset svn:keywords "URL" tools/clang/lib/Basic/Version.cpp`.
Now that we no longer use SVN, it's no longer being replaced by
anything, and we no longer offer svn exports. So remove the
$URL$-specific logic.

The "cfe" path prefix removal also no longer makes sense now that
we're on git: Both CLANG_REPOSITORY and LLVM_REPOSITORY are usually
set to https://github.com/llvm/llvm-project.git

So remove that too, and remove the "llvm" prefix removal for symmetry.
With the github url, "llvm" _is_ found in the string, but not in
the place the function expected. Nobody noticed since the llvm
repository path is only used if CLANG_REVISION and LLVM_REVISION are
different, which in the git monorepo world they never should be.
(I might remove the "// Support LLVM in a separate repository"
block in a separate commit.)

Differential Revision: https://reviews.llvm.org/D72848