Reverts llvm/llvm-project#87635

On some corner cases, lld generated an object file with an empty REL
section with `sh_info` set to 0. This file triggers an lld error when
used as its input. See
https://github.com/llvm/llvm-project/pull/87635#issuecomment-2155318065
for details.

Passing the result of c_str() to a stream is slow and redundant. This
change removes unnecessary c_str() calls and uses the string object
directly.

Caught by cppcheck -
lldb/tools/debugserver/source/JSON.cpp:398:19: performance: Passing the
result of c_str() to a stream is slow and redundant. [stlcstrStream]
lldb/tools/debugserver/source/JSON.cpp:408:64: performance: Passing the
result of c_str() to a stream is slow and redundant. [stlcstrStream]
lldb/tools/debugserver/source/JSON.cpp:420:54: performance: Passing the
result of c_str() to a stream is slow and redundant. [stlcstrStream]
lldb/tools/debugserver/source/JSON.cpp:46:13: performance: Passing the
result of c_str() to a stream is slow and redundant. [stlcstrStream]

Fix #91212

Also remove some unused Constraint paramters that appeared before
the sew parameter.

These usually have a single value that is always used. We can just
hardcode into the class body.

* generate Clang configuration file with provided target sysroot
(TOOLCHAIN_TARGET_SYSROOTFS)
* explicitly pass provided target sysroot into the compiler-rt tests
configuration.
* added ability to configure a type of the build libraries -- shared or
static (TOOLCHAIN_SHARED_LIBS, default OFF)

In behalf of: #94284

`HLSLShaderAttr::ShaderType` enum is a subset of
`llvm::Triple::EnvironmentType`. We can use
`llvm::Triple::EnvironmentType` directly and avoid converting one enum
to another.

DFSan's sscanf is incorrect
(https://github.com/llvm/llvm-project/issues/94769), which results in
erroneous matches when scraping RSS from /proc/maps. This patch works
around the issue by using strstr as a secondary check.

It also adds a loose validity check for the initial RSS measurement, to
guard against regressions in get_rss_kb().

Fixes https://github.com/llvm/llvm-project/issues/91287

[mlir] Handle the newly-added "Reserved" FramePointerKind for 1a523925 (NFC)

/llvm-project/mlir/lib/Target/LLVMIR/ModuleImport.cpp:48:
tools/mlir/include/mlir/Dialect/LLVMIR/LLVMConversionEnumsFromLLVM.inc:158:11:
error: enumeration value 'Reserved' not handled in switch [-Werror,-Wswitch]
  switch (value) {
          ^~~~~
1 error generated.

This job will run once per day on the main branch, and for every commit
on a release branch. It currently only builds llvm, but could add more
sub-projects in the future.

OpenSSF Best Practices recommends running a static analyzer on software
before it is released:
https://www.bestpractices.dev/en/criteria/0#0.static_analysis

This class is most closely related to VPatBinaryM.

These pseudoinstructions have a policy operand so calling them
TU is confusing.

VPseudoVROR can inherit from VPseudoVROL. Adjust the names to
VPseudoVROT_VV_VX and VPseudoVROT_VV_VX_VI.

The scheduler class name is hardcoded in the class so its not a
general class.

While we are at it, this patch changes the type of ValueCounts to
std:array<double, ...> so that we can use std::array:fill.

Identified with modernize-use-default-member-init.

So long as ld -r links using bitcode always result in an ELF object, and
not a merged bitcode object, the output form a relocatable link using
FatLTO objects should not have a .llvm.lto section. Prior to this, using
the object code sections would cause the bitcode section in the output
of a relocatable link to be corrupted, by concatenating all the
.llvm.lto
sections together.

This patch discards SHT_LLVM_LTO sections when not using
--fat-lto-objects, so that the relocatable ELF output won't contain
inalid bitcode.

This patch simplifies `sdiv` to `udiv` by preserving the `nsw` flag for
`(X | Op01C) + Op1C --> X + (Op01C + Op1C)` if the sum of `Op01C` and
`Op1C` will not overflow, and preserves the `nuw` flag unconditionally.

Alive2 Proofs (provided by @nikic): https://alive2.llvm.org/ce/z/nrdCZT,
https://alive2.llvm.org/ce/z/YnJHnH

We call llvm::sort in a couple of places in the V3 encoding:

- We sort Frames by FrameIds for stability of the output.

- We sort call stacks in the dictionary order to maximize the length
  of the common prefix between adjacent call stacks.

It turns out that we can improve the deserialization performance by
modifying the comparison functions -- without changing the format at
all.  Both places take advantage of the histogram of Frames -- how
many times each Frame occurs in the call stacks.

- Frames: We serialize popular Frames in the descending order of
  popularity for improved cache locality.  For two equally popular
  Frames, we break a tie by serializing one that tends to appear
  earlier in call stacks.  Here, "earlier" means a smaller index
  within llvm::SmallVector<FrameId>.

- Call Stacks: We sort the call stacks to reduce the number of times
  we follow pointers to parents during deserialization.  Specifically,
  instead of comparing two call stacks in the strcmp style -- integer
  comparisons of FrameIds, we compare two FrameIds F1 and F2 with
  Histogram[F1] < Histogram[F2] at respective indexes.  Since we
  encode from the end of the sorted list of call stacks, we tend to
  encode popular call stacks first.

Since the two places use the same histogram, we compute it once and
share it in the two places.

Sorting the call stacks reduces the number of "jumps" by 74% when we
deserialize all MemProfRecords.  The cycle and instruction counts go
down by 10% and 1.5%, respectively.

If we sort the Frames in addition to the call stacks, then the cycle
and instruction counts go down by 14% and 1.6%, respectively, relative
to the same baseline (that is, without this patch).

This is useful if you have a transcript of a user session and want to
rerun those commands with RunCommandInterpreter. The same functionality
is also useful in testing.

I'm adding it primarily for the second reason. In a subsequent patch,
I'm adding the ability to Python based commands to provide their
"auto-repeat" command. Among other things, that will allow potentially
state destroying user commands to prevent auto-repeat. Testing this with
Shell or pexpect tests is not nearly as accurate or convenient as using
RunCommandInterpreter, but to use that I need to allow auto-repeat.

I think for consistency's sake, having interactive sessions always do
auto-repeats is the right choice, though that's a lightly held
opinion...

It doesn't always have a CarryIn. One of the parameters is named
CarryIn. It always has CarryOut or a CarryIn and in some cases both.

They were always passed the same values, 1 for CarryIn and "" for
Constraint.

To help debug or surface matching issues, add more statistics to the
matching. Also add optional emission of each context seen in the
function profiles along with its allocation type, size in bytes, and
whether it was matched. This information is emitted along with a hash of
the full stack context, to allow deduplication across modules for
allocations within header files.

This patch adds `getLoopInductionVars`, `getLoopLowerBounds`,
`getLoopBounds`, `getLoopSteps` interface methods to
`LoopLIkeOpInterface`. The corresponding single value versions have been
moved to shared class declaration and have been implemented based on the
new interface methods.

This reverts commit b6824c9d.

This relands commit 0a6c74e2.

The original commit was reverted due to buildbot failures. These bots
should be updated now, so hopefully this will stick.

See Buildbot failure:
https://lab.llvm.org/buildbot/#/builders/138/builds/67337.

Add new check misc-use-internal-linkage to detect variable and function
can be marked as static.

---------

Co-authored-by: Danny Mösch <danny.moesch@icloud.com>

Part of #93566.

These instructions are very similar to narrowing shift instructions
which already have this.

Remove TargetConstraintType parameter from VPseudoBinaryV_WV
class. Only 2 was ever passed to it. Pass 2 directly to the classes
instantiated from VPseudoBinaryV_WV instead.

Summary:
Use workaround for quadratic behavior inside
AttemptToFoldSymbolOffsetDifference called from BinaryEmitter::emitLSDA.


https://github.com/llvm/llvm-project/commit/b06e736982a3568fe2bcea8688550f9e393b7450#commitcomment-142836456