Commit Graph

1111 Commits

Author SHA1 Message Date
serge-sans-paille ed98c1b376 Cleanup includes: DebugInfo & CodeGen
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121332
2022-03-12 17:26:40 +01:00
Fangrui Song 689c3a2552 [MC] Fix letter case of some MCSection member functions 2022-03-11 20:07:00 -08:00
Rainer Orth 365be7ac72 [MC][ELF] Use SHF_SUNW_NODISCARD instead of SHF_GNU_RETAIN on Solaris
As requested in D107955 <https://reviews.llvm.org/D107955>, this patch
splits off the `MC` and `CodeGen` parts and adds a testcase.

Tested on `sparcv9-sun-solaris2.11`, `amd64-pc-solaris2.11`, and
`x86_64-pc-linux-gnu`.

Differential Revision: https://reviews.llvm.org/D120318
2022-02-23 15:43:12 +01:00
Wouter van Oortmerssen d657c6893f [WebAssembly] Allow .data shorthand for .section .data,"",@ 2022-02-22 10:26:36 -08:00
Egor Zhdan 3a1cb36237 Add DriverKit support
This patch is the first in a series of patches to upstream the support for Apple's DriverKit. Once complete, it will allow targeting DriverKit platform with Clang similarly to AppleClang.

This code was originally authored by JF Bastien.

Differential Revision: https://reviews.llvm.org/D118046
2022-02-22 13:42:53 +00:00
serge-sans-paille 06943537d9 Cleanup MCParser headers
As usual with that header cleanup series, some implicit dependencies now need to
be explicit:

llvm/MC/MCParser/MCAsmParser.h no longer includes llvm/MC/MCParser/MCAsmLexer.h

Preprocessed lines to build llvm on my setup:
after:  1068185081
before: 1068324320

So no compile time benefit to expect, but we still get the looser coupling
between files which is great.

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119359
2022-02-11 10:39:29 +01:00
serge-sans-paille ef736a1c39 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
2022-02-09 11:09:17 +01:00
Kazu Hirata 3a3cb929ab [llvm] Use = default (NFC) 2022-02-06 22:18:35 -08:00
Fangrui Song 426437d1fe [MC] Add MCAsmParser::parseRParen to improve consistency and simplify code
Some diagnostics are more verbose but they don't seem to be more useful than
simple `expected ')'`
2022-01-27 00:37:49 -08:00
Fangrui Song 67c89d9a3c [MC] Remove unreachable .comm/.lcomm diagnostic
and make another diagnostic math the prevailing format.
2022-01-27 00:10:57 -08:00
Jan Svoboda 622354a522 [llvm][ADT] Implement `BitVector::{pop_,}back`
LLVM Programmer’s Manual strongly discourages the use of `std::vector<bool>` and suggests `llvm::BitVector` as a possible replacement.

Currently, some users of `std::vector<bool>` cannot switch to `llvm::BitVector` because it doesn't implement the `pop_back()` and `back()` functions.

To enable easy transition of `std::vector<bool>` users, this patch implements `llvm::BitVector::pop_back()` and `llvm::BitVector::back()`.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D117115
2022-01-21 14:50:53 +01:00
Juergen Ributzka 3025c3eded Replace PlatformKind with PlatformType.
The PlatformKind/PlatformType enums contain the same information, which requires
them to be kept in-sync. This commit changes over to PlatformType as the sole
source of truth, which allows the removal of the redundant PlatformKind.

The majority of the changes were in LLD and TextAPI.

Reviewed By: cishida

Differential Revision: https://reviews.llvm.org/D117163
2022-01-13 09:23:49 -08:00
Leonard Grey 0f85393004 [MachO] Port call graph profile section and directive
This ports the `.cg_profile` assembly directive and call graph profile section
generation to MachO from COFF/ELF. Due to MachO section naming rules, the
section is called `__LLVM,__cg_profile` rather than `.llvm.call-graph-profile`
as in COFF/ELF. Support for llvm-readobj is included to facilitate testing.

Corresponding LLD change is D112164

Differential Revision: https://reviews.llvm.org/D112160
2022-01-12 09:22:26 -05:00
Kazu Hirata b932bdf59f [llvm] Remove redundant member initialization (NFC)
Identified with readability-redundant-member-init.
2022-01-07 17:45:09 -08:00
Kazu Hirata e5947760c2 Revert "[llvm] Remove redundant member initialization (NFC)"
This reverts commit fd4808887e.

This patch causes gcc to issue a lot of warnings like:

  warning: base class ‘class llvm::MCParsedAsmOperand’ should be
  explicitly initialized in the copy constructor [-Wextra]
2022-01-03 11:28:47 -08:00
Kazu Hirata fd4808887e [llvm] Remove redundant member initialization (NFC)
Identified with readability-redundant-member-init.
2022-01-01 16:18:18 -08:00
Fangrui Song c6bf71363a [ELFAsmParser] Optimize hasPrefix with StringRef::consume_front 2021-12-30 00:16:03 -08:00
Sami Tolvanen 9a74c753fe [ThinLTO][MC] Use conditional assignments for promotion aliases
Inline assembly refererences to static functions with ThinLTO+CFI were
fixed in D104058 by creating aliases for promoted functions. Creating
the aliases unconditionally resulted in an unexpected size increase in
a Chrome helper binary:

https://bugs.chromium.org/p/chromium/issues/detail?id=1261715

This is caused by the compiler being unable to drop unused code now
referenced by the alias in module-level inline assembly. This change
adds a .set_conditional assembly extension, which emits an assignment
only if the target symbol is also emitted, avoiding phantom references
to functions that could have otherwise been dropped.

This is an alternative to the solution proposed in D112761.

Reviewed By: pcc, nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D113613
2021-12-10 12:21:37 -08:00
Phoebe Wang d7c07f60b3 [X86][MS-InlineAsm] Make the constraint *m to be simple place holder
D113096 solved the "undefined reference to xxx" issue by adding
constraint *m for the global var. But it has strong side effect due to
the symbol in the assembly being replaced with constraint variable.
This leads to some lowering fails. https://godbolt.org/z/h3nWoerPe

This patch fix the problem by use the constraint *m as place holder
rather than real constraint. It has negligible effect for the existing
code generation.

Reviewed By: skan

Differential Revision: https://reviews.llvm.org/D115225
2021-12-10 09:29:38 +08:00
Tobias Burnus c01c62c76c [MC][ELF] Fix accepting abbreviated form with Type change
Follow up to D92052 and D94072, exposed due to D107707

Many assemblers to permit that only the first .section contains all
the attributes like '.lds_bss,"w",@nobits' and later section only
use the name ('.lds_bss') inheriting those attributes from the first
section.  I turned out that the case that Type changed was missed
when implementing it - and D107707 make it much more likely to hit
that issue. That's fixed by this commit.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D114717
2021-11-30 14:45:26 +00:00
Kazu Hirata d14d7068b6 [llvm] Use StringRef::contains (NFC) 2021-10-23 08:45:27 -07:00
Anirudh Prasad fb99424a6f [SystemZ][z/OS] Introduce initial support for GOFF asm parser
- Introduce a skeleton outline for the GOFFAsmParser
- Before instantiating AsmParser/HLASMAsmParser, target specific asm parsers are attempted to be initialized first before proceeding. If it doesn't exist for a particular file type, we report a fatal error.
- This patch allows to properly instantiate the HLASMAsmParser on z/OS, and ensures we can write lit tests and unit tests which will involve the instantiation of asm parsers, without an assert / fatal error.

Reviewed By: uweigand, Kai

Differential Revision: https://reviews.llvm.org/D110730
2021-10-01 10:29:14 -04:00
Peter Smith b026ce9c8a [MC] Add Subtarget for MAsmParser call to emitCodeAlignment
The call to emitCodeAlignment was missing a STI which is required
after D45962.

emitCodeAlignment has a default parameter of 0 for MaxBytesToEmit.
Explicitly passing 0 here was interpreted as as nullptr for the STI.
This could possibly be avoided by taking STI as a const reference in
emitCodeAlignment.

Differential Revision: https://reviews.llvm.org/D109425
2021-09-08 13:28:24 +01:00
Peter Smith 5e71839f77 [MC] Add MCSubtargetInfo to MCAlignFragment
In preparation for passing the MCSubtargetInfo (STI) through to writeNops
so that it can use the STI in operation at the time, we need to record the
STI in operation when a MCAlignFragment may write nops as padding. The
STI is currently unused, a further patch will pass it through to
writeNops.

There are many places that can create an MCAlignFragment, in most cases
we can find out the STI in operation at the time. In a few places this
isn't possible as we are in initialisation or finalisation, or are
emitting constant pools. When possible I've tried to find the most
appropriate existing fragment to obtain the STI from, when none is
available use the per module STI.

For constant pools we don't actually need to use EmitCodeAlign as the
constant pools are data anyway so falling through into it via an
executable NOP is no better than falling through into data padding.

This is a prerequisite for D45962 which uses the STI to emit the
appropriate NOP for the STI. Which can differ per fragment.

Note that involves an interface change to InitSections. It is now
called initSections and requires a SubtargetInfo as a parameter.

Differential Revision: https://reviews.llvm.org/D45961
2021-09-07 15:46:19 +01:00
Tozer 5c6f748cbc [MCParser] Correctly handle CRLF line ends when consuming line comments
Fixes issue: https://bugs.llvm.org/show_bug.cgi?id=47983

The AsmLexer currently has an issue with lexing line comments in files
with CRLF line endings, in which it reads the carriage return as being
part of the line comment. This causes an error for certain valid comment
layouts; this patch fixes this by excluding the carriage return from the
line comment.

Differential Revision: https://reviews.llvm.org/D90234
2021-08-17 15:52:51 +01:00
Simon Atanasyan 990e8025b5 [MC][ELF] Do not error on parsing .debug_* section directive for MIPS
MIPS .debug_* sections should have SHT_MIPS_DWARF section type to
distinguish among sections contain DWARF and ECOFF debug formats, but in
assembly files these sections have SHT_PROGBITS (@progbits) type. Now
assembler shows 'changed section type for ...' error when parsing
`.section .debug_*,"",@progbits` directive for MIPS targets.

The same problem exists for x86-64 target and this patch extends
workaround implemented in D76151. The patch adds one more case
when assembler ignores section types mismatch after `SwitchSection()`
call.

Differential Revision: https://reviews.llvm.org/D107707
2021-08-09 08:54:56 +03:00
Arthur Eubanks ad25344620 [MC][CodeGen] Emit constant pools earlier
Previously we would emit constant pool entries for ldr inline asm at the
very end of AsmPrinter::doFinalization(). However, if we're emitting
dwarf aranges, that would end all sections with aranges. Then if we have
constant pool entries to be emitted in those same sections, we'd hit an
assert that the section has already been ended.

We want to emit constant pool entries before emitting dwarf aranges.
This patch splits out arm32/64's constant pool entry emission into its
own MCTargetStreamer virtual method.

Fixes PR51208

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D107314
2021-08-03 20:55:31 -07:00
Anirudh Prasad a8cfa4b9bd [SystemZ][z/OS] Initial code to generate assembly files on z/OS
- This patch consists of the bare basic code needed in order to generate some assembly for the z/OS target.
- Only the .text and the .bss sections are added for now.
- The relevant MCSectionGOFF/Symbol interfaces have been added. This enables us to print out the GOFF machine code sections.
- This patch enables us to add simple lit tests wherever possible, and contribute to the testing coverage for the z/OS target
- Further improvements and additions will be made in future patches.

Reviewed By: tmatheson

Differential Revision: https://reviews.llvm.org/D106380
2021-07-27 11:29:15 -04:00
Eric Astor a4e964a282 [ms] [llvm-ml] Fix macro case-insensitivity
We previously had issues identifying macros not registered with a lowercase name.

Reviewed By: mstorsjo, thakis

Differential Revision: https://reviews.llvm.org/D106453
2021-07-22 15:50:52 -04:00
Eric Astor 5fba605896 [ms] [llvm-ml] Support built-in text macros
Add support for all built-in text macros supported by ML64:
@Date, @Time, @FileName, @FileCur, and @CurSeg.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D104965
2021-07-21 11:44:09 -04:00
Eric Astor 4cbb912d75 [ms] [llvm-ml] Add support for numeric built-in symbols
Support @Version and @Line as built-in symbols. For now, resolves @Version to 1427 (the same as for the VS 2019 release of ML.EXE).

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D104964
2021-07-21 11:43:07 -04:00
Simon Tatham e49985bb60 Remove unused parameter from parseMSInlineAsm.
No implementation uses the `LocCookie` parameter at all. Errors are
reported from inside that function by `llvm::SourceMgr`, and the
instance of that at the clang call site arranges to pass the error
messages back to a `ClangAsmParserCallback`, which is where the clang
SourceLocation for the error is computed.

(This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.
But this particular change seems beneficial in its own right.)

Reviewed By: miyuki

Differential Revision: https://reviews.llvm.org/D105490
2021-07-12 15:07:03 +01:00
Eric Astor 678211de6d [ms] [llvm-ml] Standardize blocking of lexical substitution
In MASM, the ifdef family of directives treats its argument literally, without expanding it as a text macro. Add support for this, and also replace the special handling that was previously used for echo.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D104196
2021-07-02 14:17:37 -04:00
Jinsong Ji bf64210fd8 [AIX] Add dummy XCOFF MCAsmParserExtension
Implement XCOFFMCAsmParser so that we can use MC to parse inline asm.

The directives and storage mapping classes will be added later
iteratively.

Reviewed By: xgupta

Differential Revision: https://reviews.llvm.org/D105259
2021-07-02 16:12:21 +00:00
Jonas Paulsson 7aef99351a [MCStreamer] Move emission of attributes section into MCELFStreamer
Enable the emission of a GNU attributes section by reusing the code for
emitting the ARM build attributes section.

The GNU attributes follow the exact same section format as the ARM
BuildAttributes section, so this can be factored out and reused for GNU
attributes generally.

The immediate motivation for this is to emit a GNU attributes section for the
vector ABI on SystemZ (https://reviews.llvm.org/D105067).

Review: Logan Chien, Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D102894
2021-06-30 16:00:27 -05:00
Anirudh Prasad 2dca0b5a1c [AsmParser][SystemZ][z/OS] Fix hanging scenario in HLASMAsmParser class
- In the caller of the overridden `parseStatement` function (i.e. the `AsmParser::Run()`) in the case of an error **and** if we're not at the start of the statement, we "eat" up until the end of the current statement, so we don't have to process it again.
- However, in the HLASMAsmParser class what's happening is that, if an error occurs at the very start of the statement (for example, you invoke the HLASMAsmParser to parse a gnu directive), we will error out, but we never really progress in terms of the next token in the statement to parse. We simply keep looping processing the same error over and over again (partly because we're at the start of the statement)
- To remedy this, when the `parseAsHLASMLabel` function fails, before returning, we "eat" until the end of the statement function, so we don't process it anymore.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D104869
2021-06-28 12:47:08 -04:00
Eric Astor c8d0d8a8a1 [ms] [llvm-ml] Add support for ALIGN, EVEN, and ORG directives
Match ML.EXE's behavior for ALIGN, EVEN, and ORG directives both at file level and in STRUCTs.

We currently reject negative offsets passed to ORG inside STRUCTs (in ML.EXE and ML64.EXE, they wrap around as for an unsigned 32-bit integer).

Also, if a STRUCT is declared using an ORG directive, no value of that type can be defined.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D92507
2021-06-25 17:19:45 -04:00
Martin Storsjö 42f74e8249 [llvm] Rename StringRef _lower() method calls to _insensitive()
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
2021-06-25 00:22:01 +03:00
Anirudh Prasad 631362665c [AsmParser][SystemZ][z/OS] Support for emitting labels in upper case
- Currently, the emitting of labels in the parsePrimaryExpr function is case independent. It just takes the identifier and emits it.
- However, for HLASM the emitting of labels is case independent. We are emitting them in the upper case only, to enforce case independency. So we need to ensure that at the time of parsing the label we are emitting the upper case (in `parseAsHLASMLabel`), but also, when we are processing a PC-relative relocatable expression, we need to ensure we emit it in upper case (in `parsePrimaryExpr`)
- To achieve this a new MCAsmInfo attribute has been introduced which corresponding targets can override if needed.

Reviewed By: abhina.sreeskantharajan, uweigand

Differential Revision: https://reviews.llvm.org/D104715
2021-06-24 12:50:11 -04:00
RamNalamothu 167e7afcd5 Implement DW_CFA_LLVM_* for Heterogeneous Debugging
Add support in MC/MIR for writing/parsing, and DebugInfo.

This is part of the Extensions for Heterogeneous Debugging defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html

Specifically the CFI instructions implemented here are defined at
https://llvm.org/docs/AMDGPUDwarfExtensionsForHeterogeneousDebugging.html#cfa-definition-instructions

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D76877
2021-06-14 08:51:50 +05:30
Eric Astor d81c059c3e [ms] [llvm-ml] Fix capitalization of the ignored CPU directives
These directives are matched in lowercase, so make sure to use lowercase for their P suffix.

Differential Revision: https://reviews.llvm.org/D104206
2021-06-13 18:34:42 -04:00
Eric Astor f03a3caac5 [ms] [llvm-ml] Warn on command-line redefinition
If a macro is defined on the command line and then overridden in the source code, this is likely to be an error in the user's build system. We should warn on this.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D104008
2021-06-10 14:20:21 -04:00
Eric Astor 00ebbedd1c [ms] [llvm-ml] Make variable redefinition match ML.EXE
MASM specifies that all variable definitions are redefinable, except for EQU definitions to expressions. (TEXTEQU is unspecified, but appears to be fully redefinable as well.)

Also, in practice, ML.EXE allows redefinitions where the value doesn't change.

Make variable redefinition possible for text macros, suppressing expansion if written as the first argument to an EQU or TEXTEQU directive.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D103993
2021-06-10 08:36:15 -04:00
Eric Astor c8d6e67d53 [ms] [llvm-ml] Fix parity errors in error handling for INCLUDE directive
Also adds basic testing for "include" directive.

Differential Revision: https://reviews.llvm.org/D103980
2021-06-09 13:34:36 -04:00
Eric Astor dc0c3fe5f3 [ms] [llvm-ml] Disambiguate size directives and variable declarations
MASM allows statements of the form:
	<VAR> DWORD 5
to declare a variable with name <VAR>, while:
	call dword ptr [<value>]
is a valid instruction. To disambiguate, we recognize size directives by the trailing "ptr" token.

As discussed in https://lists.llvm.org/pipermail/llvm-dev/2021-May/150774.html

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D103257
2021-06-08 15:44:31 -04:00
Anirudh Prasad e52007cac4 [SystemZ][z/OS] Stricter condition for HLASM class instantiation
- A lot of lit tests simply specify the arch minus the triple. On z/OS, this could result in a scenario of some-other-triple-unknown-ibm-zos. This points to an incorrect triple + arch combo.
- To prevent this, isOSzOS change is switched in favour of isOSBinFormatGOFF.
- This is because, the GOFF format is set only if the triple is systemz and if the operating system is GOFF. And currently, there are no other architectures/os's using the GOFF file format.
- An argument could be made that the problematic tests be fixed to explicitly specify the arch-vendor-triple string, but there's a large number of these tests, and adding this stricter scope ensures that we aren't instantiating the incorrect instance of the AsmParser for other platforms when run on z/OS.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D103343
2021-06-01 15:56:50 -04:00
Anirudh Prasad b8dcd920ec [AsmParser][SystemZ][z/OS] Introducing HLASM Parser support to AsmParser - Part 2
- This patch is the second (and hopefully final) part of providing HLASM syntax for inline asm statements for z/OS to LLVM (continuing on from https://reviews.llvm.org/D98276)
- This second part deals with providing label support
- As mentioned in https://reviews.llvm.org/D98276, if the first token is not a space we process the first token as a label, and the remaining tokens as a possible machine instruction
- To achieve this, a new `parseAsHLASMLabel` function is introduced. This function processes the first token, validates whether it is an "acceptable" label according to HLASM standards, and then emits it
- After handling and emitting the label, call the `parseAsMachineInstruction` instruction to process the remaining tokens as a machine instruction.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D103320
2021-05-31 11:27:02 -04:00
Anirudh Prasad f076da66b9 [AsmParser][SystemZ][z/OS] Introducing HLASM Parser support to AsmParser - Part 1
- This patch (is one in a series of patches) which introduces HLASM Parser support (for the first parameter of inline asm statements) to LLVM ([[ https://lists.llvm.org/pipermail/llvm-dev/2021-January/147686.html | main RFC here ]])
- This patch in particular introduces HLASM Parser support for Z machine instructions.
- The approach taken here was to subclass `AsmParser`, and make various functions and variables as "protected" wherever appropriate.
- The `HLASMAsmParser` class overrides the `parseStatement` function. Two new private functions `parseAsHLASMLabel` and `parseAsMachineInstruction` are introduced as well.

The general syntax is laid out as follows (more information available in [[ https://www.ibm.com/support/knowledgecenter/SSENW6_1.6.0/com.ibm.hlasm.v1r6.asm/asmr1023.pdf | HLASM V1R6 Language Reference Manual ]] - Chapter 2 - Instruction Statement Format):

```
<TokA><spaces.*><TokB><spaces.*><TokC><spaces.*><TokD>
```

1. TokA is referred to as the Name Entry. This token is optional
2. TokB is referred to as the Operation Entry. This token is mandatory.
3. TokC is referred to as the Operand Entry. This token is mandatory
4. TokD is referred to as the Remarks Entry. This token is optional

- If TokA is provided, then we either parse TokA as a possible comment or as a label (Name Entry), Tok B as the Operation Entry and so on.
- If TokA is not provided (i.e. we have one or more spaces and then the first token), then we will parse the first token (i.e TokB) as a possible Z machine instruction, TokC as the operands to the Z machine instruction and TokD as a possible Remark field
- TokC (Operand Entry), no spaces are allowed between OperandEntries. If a space occurs it is classified as an error.
- TokD if provided is taken as is, and emitted as a comment.

The following additional approach was examined, but not taken:

- Adding custom private only functions to base AsmParser class, and only invoking them for z/OS. While this would eliminate the need for another child class, these private functions would be of non-use to every other target. Similarly, adding any pure virtual functions to the base MCAsmParser class and overriding them in AsmParser would also have the same disadvantage.

Testing:

- This patch doesn't have tests added with it, for the sole reason that MCStreamer Support and Object File support hasn't been added for the z/OS target (yet). Hence, it's not possible generate code outright for the z/OS target. They are in the process of being committed / process of being worked on.

- Any comments / feedback on how to combat this "lack of testing" due to other missing required features is appreciated.

Reviewed By: Kai, uweigand

Differential Revision: https://reviews.llvm.org/D98276
2021-05-19 11:05:30 -04:00
Sam Clegg 3041b16f73 [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
2021-05-12 13:31:02 -07:00
Sam Clegg 3b8d2be527 Reland: "[lld][WebAssembly] Initial support merging string data"
This change was originally landed in: 5000a1b4b9
It was reverted in: 061e071d8c

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
2021-05-10 16:03:38 -07:00