[MC] Remove unused includes (NFC) (#116317)

Identified with misc-include-cleaner.

[mc] Add CFI directive to emit val_offset() rules (#113971)

These specify that the value of the given register in the previous frame
is the CFA plus some offset. This isn't very common but can be n

[mc] Add CFI directive to emit val_offset() rules (#113971)

These specify that the value of the given register in the previous frame
is the CFA plus some offset. This isn't very common but can be necessary
if the original value is normally reconstructed from the stack/frame
pointer instead of being saved on the stack and reloaded from there.

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[AArch64][Libunwind] Add Support for FEAT_PAuthLR DWARF Instruction (#112171)

As part of FEAT_PAuthLR, a new DWARF Frame Instruction was introduced,
`DW_CFA_AARCH64_negate_ra_state_with_pc`. This i

[AArch64][Libunwind] Add Support for FEAT_PAuthLR DWARF Instruction (#112171)

As part of FEAT_PAuthLR, a new DWARF Frame Instruction was introduced,
`DW_CFA_AARCH64_negate_ra_state_with_pc`. This instructs Libunwind that
the PC has been used with the signing instruction. This change includes
three commits
- Libunwind support for the newly introduced DWARF Instruction
- CodeGen Support for the DWARF Instructions
- Reversing the changes made in #96377. Due to
`DW_CFA_AARCH64_negate_ra_state_with_pc`'s requirements to be placed
immediately after the signing instruction, this would mean the CFI
Instruction location was not consistent with the generated location when
not using FEAT_PAuthLR. The commit reverses the changes and makes the
location consistent across the different branch protection options.
While this does have a code size effect, this is a negligible one.

For the ABI information, see here:
https://github.com/ARM-software/abi-aa/blob/853286c7ab66048e4b819682ce17f567b77a0291/aadwarf64/aadwarf64.rst#id23

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[MC] Add .loc_label instruction (#99710)

As discussed in [the
RFC](https://discourse.llvm.org/t/rfc-extending-llvm-mc-loc-directive-with-labeling-support/79608)
we need a way to create labels in t

[MC] Add .loc_label instruction (#99710)

As discussed in [the
RFC](https://discourse.llvm.org/t/rfc-extending-llvm-mc-loc-directive-with-labeling-support/79608)
we need a way to create labels in the assembler-generated line section
in order to support the future addition of the
[DW_AT_LLVM_stmt_sequence](https://discourse.llvm.org/t/rfc-new-dwarf-attribute-for-symbolication-of-merged-functions/79434)
attribute.

We have a similar precedent for such behavior with the
[.cfi_label](https://github.com/llvm/llvm-project/pull/97922)
instruction - so we add the `.loc_label THE_LABEL_NAME` instruction
which:
- Terminates the current line sequence in the line section
- Creates a new label with the specified label name in the `.debug_line`
section

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[LLVM] Use {} instead of std::nullopt to initialize empty ArrayRef (#109133)

It is almost always simpler to use {} instead of std::nullopt to
initialize an empty ArrayRef. This patch changes all oc

[LLVM] Use {} instead of std::nullopt to initialize empty ArrayRef (#109133)

It is almost always simpler to use {} instead of std::nullopt to
initialize an empty ArrayRef. This patch changes all occurrences I could
find in LLVM itself. In future the ArrayRef(std::nullopt_t) constructor
could be deprecated or removed.

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[MC] Replace HasAggressiveSymbolFolding with SetDirectiveSuppressesReloc. NFC

The variable and its comment could lead to confusion (AMDGPU
unnecessarily set it).

[LLVM] [MC] Update frame layout & CFI generation to handle frames larger than 2gb (#99263)

Rebase of #84114. I've only included the core changes to frame layout
calculation & CFI generation which s

[LLVM] [MC] Update frame layout & CFI generation to handle frames larger than 2gb (#99263)

Rebase of #84114. I've only included the core changes to frame layout
calculation & CFI generation which sidesteps the regressions found after
merging #84114. Since these changes are a necessary precursor to the
overall fix and are themselves slightly beneficial as CFI is now
generated correctly, I think it is reasonable to merge this first step.

---

For very large stack frames, the offset from the stack pointer to a
local can be more than 2^31 which overflows various `int` offsets in the
frame lowering code.

This patch updates the frame lowering code to calculate the offsets as
64-bit values and fixes CFI to use the corrected sizes.

After this patch, additional work is needed to fix offset truncations in
each target's codegen.

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[MC] Support .cfi_label

GNU assembler 2.26 introduced the .cfi_label directive. It does not
expand to any CFI instructions, but defines a label in
.eh_frame/.debug_frame, which can be used by runtim

[MC] Support .cfi_label

GNU assembler 2.26 introduced the .cfi_label directive. It does not
expand to any CFI instructions, but defines a label in
.eh_frame/.debug_frame, which can be used by runtime patching code to
locate the FDE. .cfi_label is not allowed for CIE's initial
instructions, and can therefore be used to force the next instruction to
be placed in a FDE instead of a CIE.

In glibc since 2018, sysdeps/riscv/start.S utilizes .cfi_label to force
DW_CFA_undefined to be placed in a FDE. arc/csky/loongarch ports have
copied this use.
```
.cfi_startproc
// DW_CFA_undefined is allowed for CIE's initial instructions.
// Without .cfi_label, gas would place DW_CFA_undefined in a CIE.
.cfi_label .Ldummy
.cfi_undefined ra
.cfi_endproc
```

No CFI instruction is associated with .cfi_label, so the `case
MCCFIInstruction::OpLabel:` code in BOLT is unreachable and onlt to make
-Wswitch happy.

Close #97222

Pull Request: https://github.com/llvm/llvm-project/pull/97922

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[MC][DWARF][NFC] Drop CIEKey map (#96075)

We already sort frames by their CIEKey, so we know that we only need to
update the CIE symbol when the CIE key changes. No need for a DenseMap.

[MC] Remove setUseAssemblerInfoForParsing(false) workarounds

This reverts commit 245491a9f384e4c53421196533c2a2b693efaf8d ("[MC] Disable MCAssembler based constant folding for DwarfDebug")
and cb09b

[MC] Remove setUseAssemblerInfoForParsing(false) workarounds

This reverts commit 245491a9f384e4c53421196533c2a2b693efaf8d ("[MC] Disable MCAssembler based constant folding for DwarfDebug")
and cb09b5f3d53e5b7b4452bb3db78dca79fc9b3f17 ("[MC] Disable MCAssembler based constant folding for compact unwind and emitJumpTableEntry").

Checking the relative order of FA and FB is now faster due to
de19f7b6d46f1c38e10e604154f0fdaaffde9ebd ("[MC] Replace fragment ilist with singly-linked lists").

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[MC] Ensure UseAssemblerInfoForParsing is true upon return

Fixes: 5ee580bbfb11d781c220c19416c1a97b657e039a

5ee580bbfb11d781c220c19416c1a97b657e039a does not ensure that
UseAssemblerInfoForParsing i

[MC] Ensure UseAssemblerInfoForParsing is true upon return

Fixes: 5ee580bbfb11d781c220c19416c1a97b657e039a

5ee580bbfb11d781c220c19416c1a97b657e039a does not ensure that
UseAssemblerInfoForParsing is re-enabled. This is benign but not good.

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[MC] Disable MCAssembler based constant folding for compact unwind and emitJumpTableEntry

Similar to commit 245491a9f384e4c53421196533c2a2b693efaf8d for DwarfDebug.

This completely disables the exp

[MC] Disable MCAssembler based constant folding for compact unwind and emitJumpTableEntry

Similar to commit 245491a9f384e4c53421196533c2a2b693efaf8d for DwarfDebug.

This completely disables the expensive MCFragment walk code in
`AttemptToFoldSymbolOffsetDifference` when compiling sqlite3.i for
macOS.

In the future, we should try enabling the MCFragment walk only for
constructs like `.if . -_start == 1` and `.subsection a-b` and
remove these `setUseAssemblerInfoForParsing`.

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[MC] Make UseAssemblerInfoForParsing mostly true

Commit 6c0665e22174d474050e85ca367424f6e02476be
(https://reviews.llvm.org/D45164) enabled certain constant expression
evaluation for `MCObjectStreame

[MC] Make UseAssemblerInfoForParsing mostly true

Commit 6c0665e22174d474050e85ca367424f6e02476be
(https://reviews.llvm.org/D45164) enabled certain constant expression
evaluation for `MCObjectStreamer` at parse time (e.g. `.if` directives,
see llvm/test/MC/AsmParser/assembler-expressions.s).

`getUseAssemblerInfoForParsing` was added to make `clang -c` handling
inline assembly similar to `MCAsmStreamer` (e.g. `llvm-mc -filetype=asm`),
where such expression folding (related to
`AttemptToFoldSymbolOffsetDifference`) is unavailable.

I believe this is overly conservative. We can make some parse-time
expression folding work for `clang -c` even if `clang -S` would still
report an error, a MCAsmStreamer issue (we cannot print `.if`
directives) that should not restrict the functionality of
MCObjectStreamer.

```
% cat b.cc
asm(R"(
.pushsection .text,"ax"
.globl _start; _start: ret
.if . -_start == 1
ret
.endif
.popsection
)");
% gcc -S b.cc && gcc -c b.cc
% clang -S -fno-integrated-as b.cc # succeeded

% clang -c b.cc # succeeded with this patch
% clang -S b.cc # still failed
<inline asm>:4:5: error: expected absolute expression
4 | .if . -_start == 1
| ^
1 error generated.
```

However, removing `getUseAssemblerInfoForParsing` would make
MCDwarfFrameEmitter::Emit (for .eh_frame FDE) slow (~4% compile time
regression for sqlite3.c amalgamation) due to expensive
`AttemptToFoldSymbolOffsetDifference`. For now, make
`UseAssemblerInfoForParsing` false in MCDwarfFrameEmitter::Emit.

Close #62520
Link: https://discourse.llvm.org/t/rfc-clang-assembly-object-equivalence-for-files-with-inline-assembly/78841

Pull Request: https://github.com/llvm/llvm-project/pull/91082

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Revert rG58de1e2c5eee548a9b365e3b1554d87317072ad9 "Fix stack layout for frames larger than 2gb (#84114)"

This is failing on some EXPENSIVE_CHECKS buildbots

Fix stack layout for frames larger than 2gb (#84114)

For very large stack frames, the offset from the stack pointer to a local can be more than 2^31 which overflows various `int` offsets in the fram

Fix stack layout for frames larger than 2gb (#84114)

For very large stack frames, the offset from the stack pointer to a local can be more than 2^31 which overflows various `int` offsets in the frame lowering code.

This patch updates the frame lowering code to calculate the offsets as 64-bit values and resolves the overflows, resulting in the correct codegen for very large frames.

Fixes #48911

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[DWARF5][COFF] Emit section-relative .debug_line_str relocations (#83773)

Dwarf 5 allows separating filenames from .debug_line into a separate
.debug_line_str section. The strings are referenced re

[DWARF5][COFF] Emit section-relative .debug_line_str relocations (#83773)

Dwarf 5 allows separating filenames from .debug_line into a separate
.debug_line_str section. The strings are referenced relative to the
start of the .debug_line_str section. Previously, on COFF, the
relocation information instead caused offsets to be relocated to the
base address of the COFF-File. This lead to wrong offsets in linked
COFF (PE) files which caused the debugger to be unable to find the
correct source files.

This patch fixes this problem by making the offsets relative to the
start of the .debug_line_str section instead. There should be no
changes for ELF-Files as everything seems to be working there.

A test is also added to ensure that the correct relocation entries are
emitted.

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[llvm] Use StringRef::{starts,ends}_with (NFC) (#74956)

This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::

[llvm] Use StringRef::{starts,ends}_with (NFC) (#74956)

This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.

I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.

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Allow for mixing source/no-source DIFiles in one CU

The DWARF proposal that the DW_LNCT_LLVM_source extension is based on
(https://dwarfstd.org/issues/180201.1.html) allows to mix source and
non-sou

Allow for mixing source/no-source DIFiles in one CU

The DWARF proposal that the DW_LNCT_LLVM_source extension is based on
(https://dwarfstd.org/issues/180201.1.html) allows to mix source and
non-source files in the same CU by storing an empty string as a
sentinel value.

This patch implements this feature.

Review in https://github.com/llvm/llvm-project/pull/73877

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Use llvm::endianness::{big,little,native} (NFC)

Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces suppo

Use llvm::endianness::{big,little,native} (NFC)

Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.

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Use llvm::endianness (NFC)

Now that llvm::support::endianness has been renamed to
llvm::endianness, we can use the shorter form. This patch replaces
support::endianness with llvm::endianness.

[BOLT][DWARF] Fix for .debug_line with DWARF5

There was a bug in a code that pre-populated line string for a case where parts
of .debug_line are not processed by BOLT, but copied as raw data. We wer

[BOLT][DWARF] Fix for .debug_line with DWARF5

There was a bug in a code that pre-populated line string for a case where parts
of .debug_line are not processed by BOLT, but copied as raw data. We were not
switching sections. This resulted in parts of the binary being over-written with
debug data.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D154544

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[MC] Report location information for MCDwarfCallFrameFragment diagnostics

[MC] Add SMLoc to MCCFIInstruction

to help debug and report better diagnostics for functions like
relaxDwarfCallFrameFragment (D153167).

In MCStreamer, some emitCFI* functions already take a SMLoc

[MC] Add SMLoc to MCCFIInstruction

to help debug and report better diagnostics for functions like
relaxDwarfCallFrameFragment (D153167).

In MCStreamer, some emitCFI* functions already take a SMLoc argument. Add a
SMLoc argument to the remaining functions that generate a MCCFIInstruction.

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[DWARF][MC] improve the error message when DwarfLineStrSection is null.

Summary: Currently the crush info is ambiguous when DwarfLineStrSection is null. The patch adds an assertion in the constructo

[DWARF][MC] improve the error message when DwarfLineStrSection is null.

Summary: Currently the crush info is ambiguous when DwarfLineStrSection is null. The patch adds an assertion in the constructor of MCDwarfLineStr when DwarfLineStrSection is null.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D149121

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MCDwarfFrameEmitter::EncodeAdvanceLoc: use SmallVectorImpl instead of raw_ostream. NFC

Similar to 49488490d195591bfc90daef111cd7293f8c80aa.
Remove MCDwarfFrameEmitter::EmitAdvanceLoc which is only c

MCDwarfFrameEmitter::EncodeAdvanceLoc: use SmallVectorImpl instead of raw_ostream. NFC

Similar to 49488490d195591bfc90daef111cd7293f8c80aa.
Remove MCDwarfFrameEmitter::EmitAdvanceLoc which is only called once.

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