[MC] Make MCSection::isVirtualSection non-virtual (#96920)

This method is called once per encoded instruction, but never changes
throughout the lifetime of a section. Store this information as a bi

[MC] Make MCSection::isVirtualSection non-virtual (#96920)

This method is called once per encoded instruction, but never changes
throughout the lifetime of a section. Store this information as a bit
flag in the MCSection instead.

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[MC] Change Subsection parameters from const MCExpr * to uint32_t

Follow-up to 05ba5c0648ae5e80d5afce270495bf3b1eef9af4. uint32_t is
preferred over const MCExpr * in the section stack uses because i

[MC] Change Subsection parameters from const MCExpr * to uint32_t

Follow-up to 05ba5c0648ae5e80d5afce270495bf3b1eef9af4. uint32_t is
preferred over const MCExpr * in the section stack uses because it
should only be evaluated once. Change the paramter type to match.

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[WebAssembly] Add segment RETAIN flag to support private retained data (#81539)

In WebAssembly, we have `WASM_SYMBOL_NO_STRIP` symbol flag to mark the
referenced content as retained. However, the f

[WebAssembly] Add segment RETAIN flag to support private retained data (#81539)

In WebAssembly, we have `WASM_SYMBOL_NO_STRIP` symbol flag to mark the
referenced content as retained. However, the flag is not enough to
express retained data that is not referenced by any symbol. This patch
adds a new segment flag`WASM_SEG_FLAG_RETAIN` to support "private"
linkage data that is retained by llvm.used.

This kind of data that is not referenced but must be retained is usually
used with encapsulation symbols (__start/__stop). Swift runtime uses
this technique and depends on the fact "all metadata sections in live
objects are retained", which was not guaranteed with `--gc-sections`
before this patch.

This is a revised version of https://reviews.llvm.org/D126950 (has been
reverted) based on @MaskRay's comments

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[MC] Fix letter case of some MCSection member functions

Cleanup LLVMMC headers

There's a few relevant forward declarations in there that may require downstream
adding explicit includes:

llvm/MC/MCContext.h no longer includes llvm/BinaryFormat/ELF.h, llv

Cleanup LLVMMC headers

There's a few relevant forward declarations in there that may require downstream
adding explicit includes:

llvm/MC/MCContext.h no longer includes llvm/BinaryFormat/ELF.h, llvm/MC/MCSubtargetInfo.h, llvm/MC/MCTargetOptions.h
llvm/MC/MCObjectStreamer.h no longer include llvm/MC/MCAssembler.h
llvm/MC/MCAssembler.h no longer includes llvm/MC/MCFixup.h, llvm/MC/MCFragment.h

Counting preprocessed lines required to rebuild llvm-project on my setup:
before: 1052436830
after: 1049293745

Which is significant and backs up the change in addition to the usual benefits of
decreasing coupling between headers and compilation units.

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119244

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[WebAssembly] Add TLS data segment flag: WASM_SEG_FLAG_TLS

Previously the linker was relying solely on the name of the segment
to imply TLS.

Differential Revision: https://reviews.llvm.org/D102202

Reland: "[lld][WebAssembly] Initial support merging string data"

This change was originally landed in: 5000a1b4b9edeb9e994f2a5b36da8d48599bea49
It was reverted in: 061e071d8c9b98526f35cad55a918a4f16

Reland: "[lld][WebAssembly] Initial support merging string data"

This change was originally landed in: 5000a1b4b9edeb9e994f2a5b36da8d48599bea49
It was reverted in: 061e071d8c9b98526f35cad55a918a4f1615afd4

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657

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Revert "[lld][WebAssembly] Initial support merging string data"

This reverts commit 5000a1b4b9edeb9e994f2a5b36da8d48599bea49.
Breaks tests, see https://reviews.llvm.org/D97657#2749151

Easily repros

Revert "[lld][WebAssembly] Initial support merging string data"

This reverts commit 5000a1b4b9edeb9e994f2a5b36da8d48599bea49.
Breaks tests, see https://reviews.llvm.org/D97657#2749151

Easily repros locally with `ninja check-llvm-mc-webassembly`.

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[lld][WebAssembly] Initial support merging string data

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF w

[lld][WebAssembly] Initial support merging string data

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657

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[WebAssembly] Support COMDAT sections in assembly syntax

This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G"

[WebAssembly] Support COMDAT sections in assembly syntax

This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.

This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.

Differential Revision: https://reviews.llvm.org/D92952
This is a reland of rG4564553b8d8a with a fix to the lit pipeline in
llvm/test/MC/WebAssembly/comdat.ll

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Revert "[WebAssembly] Support COMDAT sections in assembly syntax"

This reverts commit 4564553b8d8ab81dc21431a35275581cb42329c8.
It broke several buildbots.

[WebAssembly] Support COMDAT sections in assembly syntax

This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G"

[WebAssembly] Support COMDAT sections in assembly syntax

This CL changes the asm syntax for section flags, making them more like ELF
(previously "passive" was the only option). Now we also allow "G" to designate
COMDAT group sections. In these sections we set the appropriate comdat flag on
function symbols, and also avoid auto-creating a new section for them.

This also adds asm-based tests for the changes D92691 to go along with
the direct-to-object tests.

Differential Revision: https://reviews.llvm.org/D92952

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MCSectionWasm.h - reduce includes to forward declarations. NFC.

[MC] Replace MCSection*::getName() with MCSection::getName(). NFC

I plan to use MCSection::getName() in D78138. Having the function in the base class is also convenient for debugging.

Reviewed By:

[MC] Replace MCSection*::getName() with MCSection::getName(). NFC

I plan to use MCSection::getName() in D78138. Having the function in the base class is also convenient for debugging.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D78251

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[MC] Rename MCSection*::getSectionName() to getName(). NFC

A pending change will merge MCSection*::getName() to MCSection::getName().

[WebAssembly] Update MC for bulk memory

Summary:
Rename MemoryIndex to InitFlags and implement logic for determining
data segment layout in ObjectYAML and MC. Also adds a "passive" flag
for the .sec

[WebAssembly] Update MC for bulk memory

Summary:
Rename MemoryIndex to InitFlags and implement logic for determining
data segment layout in ObjectYAML and MC. Also adds a "passive" flag
for the .section assembler directive although this cannot be assembled
yet because the assembler does not support data sections.

Reviewers: sbc100, aardappel, aheejin, dschuff

Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57938

llvm-svn: 354397

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[MC] Clean up unused inline function and non-anchor defaulted destructors; NFCI

Summary:
Take care of some missing clean-ups that belong with r249548 and some
other copy/paste that had happened. In

[MC] Clean up unused inline function and non-anchor defaulted destructors; NFCI

Summary:
Take care of some missing clean-ups that belong with r249548 and some
other copy/paste that had happened. In particular, the destructors are
no longer vtable anchors after r249548; and `setSectionName` in
`MCSectionWasm` is private and unused since r313058 culled its only
caller. The destructors are now implicitly defined, and the unused
function is removed.

Reviewers: nemanjai, jasonliu, grosbach

Reviewed By: nemanjai

Subscribers: sbc100, aheejin, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57182

llvm-svn: 353597

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[WebAssembly] clang-tidy (NFC)

Summary:
This patch fixes clang-tidy warnings on wasm-only files.
The list of checks used is:
`-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-

[WebAssembly] clang-tidy (NFC)

Summary:
This patch fixes clang-tidy warnings on wasm-only files.
The list of checks used is:
`-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming,modernize-*`
(LLVM's default .clang-tidy list is the same except it does not have
`modernize-*`. But I've seen in multiple CLs in LLVM the modernize style
was recommended and code was fixed based on the style, so I added it as
well.)

The common fixes are:
- Variable names start with an uppercase letter
- Function names start with a lowercase letter
- Use `auto` when you use casts so the type is evident
- Use inline initialization for class member variables
- Use `= default` for empty constructors / destructors
- Use `using` in place of `typedef`

Reviewers: sbc100, tlively, aardappel

Subscribers: dschuff, sunfish, jgravelle-google, yurydelendik, kripken, MatzeB, mgorny, rupprecht, llvm-commits

Differential Revision: https://reviews.llvm.org/D57500

llvm-svn: 353075

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Remove redundant includes from lib/MC.

llvm-svn: 320624

[WebAssembly] Add skeleton MC support for the Wasm container format

This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in follo

[WebAssembly] Add skeleton MC support for the Wasm container format

This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.

Differential Revision: https://reviews.llvm.org/D26722

llvm-svn: 295803

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