In a LTO build, the `end_sequence` in debug_line table for each compile unit (CU) points the end of text section which merged all CUs. The `end_sequence` needs to point to the end of each CU's range. This bug often causes invalid `debug_line` table in the final `.dSYM` binary for MachO after running `dsymutil` which tries to compensate an out-of-range address of `end_sequence`.
The fix is to sync the line table termination with the range operations that are already maintained in DwarfDebug. When CU or section changes, or nodebug functions appear or module is finished, the prior pending line table is terminated using the last range label. In the MC path where no range is tracked, the old logic is conservatively used to end the line table using the section end symbol.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D108261
[NFC] This patch fixes URLs containing "master". Old URLs were either broken or
redirecting to the new URL.
Reviewed By: #libc, ldionne, mehdi_amini
Differential Revision: https://reviews.llvm.org/D113186
If a tool wants to introduce new indirections via stubs at link-time in
ORC, it can cause fidelity issues around the address of the function if
some references to the function do not have relocations. This is known
to happen inside the body of the function itself on x86_64 for example,
where a PC-relative address is formed, but without a relocation.
```
_foo:
leaq -7(%rip), %rax ## form pointer to '_foo' without relocation
_bar:
leaq (%rip), %rax ## uses X86_64_RELOC_SIGNED to '_foo'
```
The consequence of introducing a stub for such a function at link time
is that if it forms a pointer to itself without relocation, it will not
have the same value as a pointer from outside the function. If the
function pointer is used as a key, this can cause problems.
This utility provides best-effort support for adding such missing
relocations using MCDisassembler and MCInstrAnalysis to identify the
problematic instructions. Currently it is only implemented for x86_64.
Note: the related issue with call/jump instructions is not handled
here, only forming function pointers.
rdar://83514317
Differential revision: https://reviews.llvm.org/D113038
Emit __clangast in custom section instead of named data segment
to find it while iterating sections.
This could be avoided if all data segements (the wasm sense) were
represented as their own sections (in the llvm sense).
This can be resolved by https://github.com/WebAssembly/tool-conventions/issues/138
And the on-disk hashtable in clangast needs to be aligned by 4 bytes,
so add paddings in name length field in custom section header.
The length of clangast section name can be represented in 1 byte
by leb128, and possible maximum pads are 3 bytes, so the section
name length won't be invalid in theory.
Fixes https://bugs.llvm.org/show_bug.cgi?id=35928
Differential Revision: https://reviews.llvm.org/D74531
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of report_fatal_error(const std::string&) with the Twine() variant which can be forward declared.
This removes `WasmTagType`. `WasmTagType` contained an attribute and a
signature index:
```
struct WasmTagType {
uint8_t Attribute;
uint32_t SigIndex;
};
```
Currently the attribute field is not used and reserved for future use,
and always 0. And that this class contains `SigIndex` as its property is
a little weird in the place, because the tag type's signature index is
not an inherent property of a tag but rather a reference to another
section that changes after linking. This makes tag handling in the
linker also weird that tag-related methods are taking both `WasmTagType`
and `WasmSignature` even though `WasmTagType` contains a signature
index. This is because the signature index changes in linking so it
doesn't have any info at this point. This instead moves `SigIndex` to
`struct WasmTag` itself, as we did for `struct WasmFunction` in D111104.
In this CL, in lib/MC and lib/Object, this now treats tag types in the
same way as function types. Also in YAML, this removes `struct Tag`,
because now it only contains the tag index. Also tags set `SigIndex` in
`WasmImport` union, as functions do.
I think this makes things simpler and makes tag handling more in line
with function handling. These two shares similar properties in that both
of them have signatures, but they are kind of nominal so having the same
signature doesn't mean they are the same element.
Also a drive-by fix: the reserved 'attirubute' part's encoding changed
from uleb32 to uint8 a while ago. This was fixed in lib/MC and
lib/Object but not in YAML. This doesn't change object files because the
field's value is always 0 and its encoding is the same for the both
encoding.
This is effectively NFC; I didn't mark it as such just because it
changed YAML test results.
Reviewed By: sbc100, tlively
Differential Revision: https://reviews.llvm.org/D111086
- 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
Add MCDwarfLineStr class to the public API.
Note that MCDwarfLineTableHeader::Emit(), takes MCDwarfLineStr as
an Optional<> parameter making it impossible to use the API if the class
is not publicly defined.
Reviewed By: alexander-shaposhnikov
Differential Revision: https://reviews.llvm.org/D109412
- This patch adds in the GOFFMCAsmInfo interfaces for the z/OS target.
- This patch decouples the previously existing SystemZMCAsmInfo interface for the ELF target and the z/OS target.
- This patch also removes a small test in the SystemZAsmLexerTest.cpp. The reason for this is because, the test is set up for the s390x-ibm-linux (SystemZ ELF triple), and the test checks a function which is overridden only for the z/OS target. The reason we can't change the test to use a z/OS triple outright is because there is still missing support which prevents the successful running of a test (assert in AsmParser.cpp due to missing GOFFAsmParser support)
Reviewed By: uweigand, abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D110077
We previously had a limitation that TLS variables could not
be exported (and therefore could also not be imported). This
change removed that limitation.
Differential Revision: https://reviews.llvm.org/D108877
Previously the relocations pointed at the public user facing,
possibly external symbol.
When the function itself is weak, that symbol may be overridden at
link time, pointing at another strong implementation of the same
function instead. In that case, there's two conflicting pdata entries
pointing at the same address, and the wrong unwind info might end up
used.
Both GCC/binutils and MSVC produce pdata pointing at internal static
symbols. (GCC/binutils point at the .text section just as LLVM does
after this change, MSVC points at special label type symbols with the
type IMAGE_SYM_CLASS_LABEL and names like '$LN4'.)
This fixes unwinding through an overridden "operator new" with a
statically linked C++ library in MinGW mode. (Building libc++ with
-ffunction-sections and linking with --gc-sections might avoid the
issue too.)
This makes the produced object files a little less user friendly
to debug, but with other recent improvements for llvm-readobj, the
unwind info debugging experience should be pretty much the same.
Differential Revision: https://reviews.llvm.org/D109651
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
On some architectures such as Arm and X86 the encoding for a nop may
change depending on the subtarget in operation at the time of
encoding. This change replaces the per module MCSubtargetInfo retained
by the targets AsmBackend in favour of passing through the local
MCSubtargetInfo in operation at the time.
On Arm using the architectural NOP instruction can have a performance
benefit on some implementations.
For Arm I've deleted the copy of the AsmBackend's MCSubtargetInfo to
limit the chances of this causing problems in the future. I've not
done this for other targets such as X86 as there is more frequent use
of the MCSubtargetInfo and it looks to be for stable properties that
we would not expect to vary per function.
This change required threading STI through MCNopsFragment and
MCBoundaryAlignFragment.
I've attempted to take into account the in tree experimental backends.
Differential Revision: https://reviews.llvm.org/D45962
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
This add support for SjLj using Wasm exception handling instructions:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/exception-handling/Exceptions.md
This does not yet support the mixed use of EH and SjLj within a
function. It will be added in a follow-up CL.
This currently passes all SjLj Emscripten tests for wasm0/1/2/3/s,
except for the below:
- `test_longjmp_standalone`: Uses Node
- `test_dlfcn_longjmp`: Uses NodeRAWFS
- `test_longjmp_throw`: Mixes EH and SjLj
- `test_exceptions_longjmp1`: Mixes EH and SjLj
- `test_exceptions_longjmp2`: Mixes EH and SjLj
- `test_exceptions_longjmp3`: Mixes EH and SjLj
Reviewed By: dschuff, tlively
Differential Revision: https://reviews.llvm.org/D108960
sh_info links to a section, therefore SHF_INFO_LINK should be set as GNU as
does. The issue has been benign because linkers kindly combines relocation
sections w/ and w/o the flag.
Currently context strings contain a lot of duplicated function names and that significantly increase the profile size. This change split the context into a series of {name, offset, discriminator} tuples so function names used in the context can be replaced by the index into the name table and that significantly reduce the size consumed by context.
A follow-up improvement made in the compiler and profiling tools is to avoid reconstructing full context strings which is time- and memory- consuming. Instead a context vector of `StringRef` is adopted to represent the full context in all scenarios. As a result, the previous prevalent profile map which was implemented as a `StringRef` is now engineered as an unordered map keyed by `SampleContext`. `SampleContext` is reshaped to using an `ArrayRef` to represent a full context for CS profile. For non-CS profile, it falls back to use `StringRef` to represent a contextless function name. Both the `ArrayRef` and `StringRef` objects are underpinned by real array and string objects that are stored in producer buffers. For compiler, they are maintained by the sample reader. For llvm-profgen, they are maintained in `ProfiledBinary` and `ProfileGenerator`. Full context strings can be generated only in those cases of debugging and printing.
When it comes to profile format, nothing has changed to the text format, though internally CS context is implemented as a vector. Extbinary format is only changed for CS profile, with an additional `SecCSNameTable` section which stores all full contexts logically in the form of `vector<int>`, which each element as an offset points to `SecNameTable`. All occurrences of contexts elsewhere are redirected to using the offset of `SecCSNameTable`.
Testing
This is no-diff change in terms of code quality and profile content (for text profile).
For our internal large service (aka ads), the profile generation is cut to half, with a 20x smaller string-based extbinary format generated.
The compile time of ads is dropped by 25%.
Differential Revision: https://reviews.llvm.org/D107299
This makes sure, that the text section will have a 2-byte alignment, if
the +c extension is enabled.
Reviewed By: MaskRay, luismarques
Differential Revision: https://reviews.llvm.org/D102052
Similar to D97976.
On Linux, most GCC installations are configured with
`--enable-gnu-unique-object` and such GCC emits `@gnu_unique_object` assembly.
The feature is highly controversial and disliked by many folks.
(On glibc DF_1_NODELETE is implicitly enabled and makes dlclose a no-op).
In llvm-project STB_GNU_UNIQUE is assembly only. Clang does not use STB_GNU_UNIQUE.
Use ELFOSABI_GNU to match GNU as behavior and avoid collision with other
OSABI binding values.
Reviewed By: jrtc27
Differential Revision: https://reviews.llvm.org/D107861
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
Pseudo probe descriptors are created very early in the pipeline where function names just come from the front end and are not yet decorated. So calling getCanonicalFnName on the function names in probe desc is basically a no-op, which also addes a depenency from MC to ProfileData unnessesarily.
Reviewed By: wenlei, wlei
Differential Revision: https://reviews.llvm.org/D107838
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
Fixes issue where late materialized constants can be more strictly
aligned then their containing csect.
Differential Revision: https://reviews.llvm.org/D103103
D106861 added usage of PseudoProbeAttributes::Reserved as TailCall however this usage hasn't been committed/reviewed. Removing this usage.
Testing
ninja check-all
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D107514
Migrate pseudo probe decoding logic in llvm-profgen to MC, so other LLVM-base program could reuse existing codes. Redesign object layout of encoded and decoded pseudo probes.
Reviewed By: hoy
Differential Revision: https://reviews.llvm.org/D106861
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
- 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
We previously had issues identifying macros not registered with a lowercase name.
Reviewed By: mstorsjo, thakis
Differential Revision: https://reviews.llvm.org/D106453
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
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
Debug info sections need R_WASM_FUNCTION_OFFSET_I32 relocs (with FK_Data_4 fixup
kinds) to refer to functions (instead of R_WASM_TABLE_INDEX as is used in data
sections). Usually this is done in a convoluted way, with unnamed temp data
symbols which target the start of the function, in which case
WasmObjectWriter::recordRelocation converts it to use the section symbol
instead. However in some cases the function can actually be undefined; in this
case the dwarf generator uses the function symbol (a named undefined function
symbol) instead. In that case the section-symbol transform doesn't work and we
need to generate the correct reloc type a different way. In this change
WebAssemblyWasmObjectWriter::getRelocType takes the fixup section type into
account to choose the correct reloc type.
Fixes PR50408
Differential Revision: https://reviews.llvm.org/D103557
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
This to protect against non-sensical instruction sequences being assembled,
which would either cause asserts/crashes further down, or a Wasm module being output that doesn't validate.
Unlike a validator, this type checker is able to give type-errors as part of the parsing process, which makes the assembler much friendlier to be used by humans writing manual input.
Because the MC system is single pass (instructions aren't even stored in MC format, they are directly output) the type checker has to be single pass as well, which means that from now on .globaltype and .functype decls must come before their use. An extra pass is added to Codegen to collect information for this purpose, since AsmPrinter is normally single pass / streaming as well, and would otherwise generate this information on the fly.
A `-no-type-check` flag was added to llvm-mc (and any other tools that take asm input) that surpresses type errors, as a quick escape hatch for tests that were not intended to be type correct.
This is a first version of the type checker that ignores control flow, i.e. it checks that types are correct along the linear path, but not the branch path. This will still catch most errors. Branch checking could be added in the future.
Differential Revision: https://reviews.llvm.org/D104945
C++23 will make these conversions ambiguous - so fix them to make the
codebase forward-compatible with C++23 (& a follow-up change I've made
will make this ambiguous/invalid even in <C++23 so we don't regress
this & it generally improves the code anyway)
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
Add a flag so that target can choose to use AsmParser for parsing inline asm.
And set the flag by default for AIX.
-no-intergrated-as will override this default if specified explicitly.
Reviewed By: #powerpc, shchenz
Differential Revision: https://reviews.llvm.org/D105314
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
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
- 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
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
... even on targets preferring RELA. The section is only consumed by ld.lld
which can handle REL.
Follow-up to D104080 as I explained in the review. There are two advantages:
* The D104080 code only handles RELA, so arm/i386/mips32 etc may warn for -fprofile-use=/-fprofile-sample-use= usage.
* Decrease object file size for RELA targets
While here, change the relocation to relocate weights, instead of 0,1,2,3,..
I failed to catch the issue during review.
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.
- 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
Currently when .llvm.call-graph-profile is created by llvm it explicitly encodes the symbol indices. This section is basically a black box for post processing tools. For example, if we run strip -s on the object files the symbol table changes, but indices in that section do not. In non-visible behavior indices point to wrong symbols. The visible behavior indices point outside of Symbol table: "invalid symbol index".
This patch changes the format by using R_*_NONE relocations to indicate the from/to symbols. The Frequency (Weight) will still be in the .llvm.call-graph-profile, but symbol information will be in relocation section. In LLD information from both sections is used to reconstruct call graph profile. Relocations themselves will never be applied.
With this approach post processing tools that handle relocations correctly work for this section also. Tools can add/remove symbols and as long as they handle relocation sections with this approach information stays correct.
Doing a quick experiment with clang-13.
The size went up from 107KB to 322KB, aggregate of all the input sections. Size of clang-13 binary is ~118MB. For users of -fprofile-use/-fprofile-sample-use the size of object files will go up slightly, it will not impact final binary size.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D104080
This changes the encoding of the `attribute` field, which currently only
contains the value `0` denoting this tag is for an exception, from
`varuint32` to `uint8`. This field is effectively unused at the moment
and reserved for future use, and it is not likely to need `varuint32`
even in future.
See https://github.com/WebAssembly/exception-handling/pull/162.
This does not change any encoded binaries because `0` is encoded in the
same way both in `varuint32` and `uint8`.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D104571
This re-architects the RISCV relocation handling to bring the
implementation closer in line with the implementation in binutils. We
would previously aggressively resolve the relocation. With this
restructuring, we always will emit a paired relocation for any symbolic
difference of the type of S±T[±C] where S and T are labels and C is a
constant.
GAS has a special target hook controlled by `RELOC_EXPANSION_POSSIBLE`
which indicates that a fixup may be expanded into multiple relocations.
This is used by the RISCV backend to always emit a paired relocation -
either ADD[WIDTH] + SUB[WIDTH] for text relocations or SET[WIDTH] +
SUB[WIDTH] for a debug info relocation. Irrespective of whether linker
relaxation support is enabled, symbolic difference is always emitted as
a paired relocation.
This change also sinks the target specific behaviour down into the
target specific area rather than exposing it to the shared relocation
handling. In the process, we also sink the "special" handling for debug
information down into the RISCV target. Although this improves the path
for the other targets, this is not necessarily entirely ideal either.
The changes in the debug info emission could be done through another
type of hook as this functionality would be required by any other target
which wishes to do linker relaxation. However, as there are no other
targets in LLVM which currently do this, this is a reasonable thing to
do until such time as the code needs to be shared.
Improve the handling of the relocation (and add a reduced test case from
the Linux kernel) to ensure that we handle complex expressions for
symbolic difference. This ensures that we correct relocate symbols with
the adddends normalized and associated with the addition portion of the
paired relocation.
This change also addresses some review comments from Alex Bradbury about
the relocations meant for use in the DWARF CFA being named incorrectly
(using ADD6 instead of SET6) in the original change which introduced the
relocation type.
This resolves the issues with the symbolic difference emission
sufficiently to enable building the Linux kernel with clang+IAS+lld
(without linker relaxation).
Resolves PR50153, PR50156!
Fixes: ClangBuiltLinux/linux#1023, ClangBuiltLinux/linux#1143
Reviewed By: nickdesaulniers, maskray
Differential Revision: https://reviews.llvm.org/D103539
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
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
Summary: Some structs like FileHeader32/SectionHeader32
defined in llvm/include/llvm/BinaryFormat/XCOFF.h seem
unnecessary, because we only need their size. So this
patch removes them and defines size constants directly.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D103901
This is a followup to D103422. The DenseMapInfo implementations for
ArrayRef and StringRef are moved into the ArrayRef.h and StringRef.h
headers, which means that these two headers no longer need to be
included by DenseMapInfo.h.
This required adding a few additional includes, as many files were
relying on various things pulled in by ArrayRef.h.
Differential Revision: https://reviews.llvm.org/D103491
- 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
- 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
Global values imply flags such as readable, writable, executable for the
sections that they will be placed in. Currently MC places all such
entries into the same section, using the first set of flags seen. This
can lead to situations in LTO where a writable global is placed in the
same named section as a readable global from another file, and the
section may not be marked writable.
D72194 ensures that mergeable globals with explicit sections are placed
in separate sections with compatible entry size, by emitting the
`unique` assembly syntax where appropriate. This change extends that
approach to include section flags, so that globals with different
section flags are emitted in separate unique sections.
Differential revision: https://reviews.llvm.org/D100944
This makes it possible for targets to define their own MCObjectFileInfo.
This MCObjectFileInfo is then used to determine things like section alignment.
This is a follow up to D101462 and prepares for the RISCV backend defining the
text section alignment depending on the enabled extensions.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101921
.byte supports string, so if the whole byte list are printable,
we can actually print the string for readability and LIT tests maintainence.
.byte 'H,'e,'l,'l,'o,',,' ,'w,'o,'r,'l,'d
->
.byte "Hello, world"
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D102814
__table_base is know 64-bit, since in LLVM it represents a function pointer offset
__table_base32 is a copy in wasm32 for use in elem init expr, since no truncation may be used there.
New reloc R_WASM_TABLE_INDEX_REL_SLEB64 added
Differential Revision: https://reviews.llvm.org/D101784
- 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
Adds the ability to pass MCRegisterInfo to dump_pretty and to the print functions,
so that if present, target specific enums names are printed instead of enum values.
This matches how they are defined on X86.
This should fix the relative lookup tables pass for COFF, allowing
it to be reenabled.
Differential Revision: https://reviews.llvm.org/D102217
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
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
- Add branch absolute reloction R_RBA, R_TLS relocation for the variable offset
for the tlsgd model and R_TLSM for the region handle for the tlsgd model
- Properly set the relocation fixed values for R_TLS and R_TLSM
- Emit the TCEntry with the variant kind in the XCOFFStreamer
Reviewed by: sfertile, nemanjai, DiggerLin
Differential Revision: https://reviews.llvm.org/D100214
This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.
This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:
- TargetTriple
- ObjectFileType
- SubtargetInfo
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101462
- As per the HLASM support we are providing, i.e. support only for the first parameter of the inline asm block, only pertaining to Z machine instructions defined in LLVM, character literals and string literals are not supported (see Figure 4 - https://www-01.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R3sc264940/$file/asmr1023.pdf for more information)
- This patch explicitly rejects the usage of char literals and string literals (for example "abc 'a'") when the relevant field is set
- This is achieved by introducing a field called `LexHLASMStrings` in MCAsmLexer similar to `LexMasmStrings`
Reviewed By: abhina.sreeskantharajan, Kai
Differential Revision: https://reviews.llvm.org/D101660
This fixes PR49821, and avoids "ld.lld: error: test.o:(.rodata.str1.1):
offset is outside the section" errors when linking MIPS objects with
negative R_MIPS_LO16 implicit addends.
ld.lld handles R_MIPS_HI16/R_MIPS_LO16 separately, not as a whole, so it
doesn't know that an R_MIPS_HI16 with implicit addend 1 and an
R_MIPS_LO16 with implicit addend -32768 represents 32768, which is in
range of a MergeInputSection. We could introduce a new RelExpr member
(like R_RISCV_PC_INDIRECT for R_RISCV_PCREL_HI20 / R_RISCV_PCREL_LO12)
but the complexity is unnecessary given that GNU as keeps the original
symbol for this case as well.
Adds a new test case for PR49821, and also updates two other test cases
that are affected by this change.
Reviewed By: atanasyan, MaskRay
Differential Revision: https://reviews.llvm.org/D101773
This reverts commit ab40c027f0.
Some additional test cases are influenced by the workaround, and I need
to do a complete test run to identify and check them all.
This fixes PR49821, and avoids "ld.lld: error: test.o:(.rodata.str1.1):
offset is outside the section" errors when linking MIPS objects with
negative R_MIPS_LO16 implicit addends.
ld.lld handles R_MIPS_HI16/R_MIPS_LO16 separately, not as a whole, so it
doesn't know that an R_MIPS_HI16 with implicit addend 1 and an
R_MIPS_LO16 with implicit addend -32768 represents 32768, which is in
range of a MergeInputSection. We could introduce a new RelExpr member
(like R_RISCV_PC_INDIRECT for R_RISCV_PCREL_HI20 / R_RISCV_PCREL_LO12)
but the complexity is unnecessary given that GNU as keeps the original
symbol for this case as well.
Reviewed By: atanasyan, MaskRay
Differential Revision: https://reviews.llvm.org/D101773
- This patch attempts to implement the location counter syntax (*) for the HLASM variant for PC-relative instructions.
- In the HLASM variant, for purely constant relocatable values, we expect a * token preceding it, with special support for " *" which is parsed as "<pc-rel-insn 0>"
- For combinations of absolute values and relocatable values, we don't expect the "*" preceding the token.
When you have a " * " what’s accepted is:
```
*<space>.*{.*} -> <pc-rel-insn> 0
*[+|-][constant-value] -> <pc-rel-insn> [+|-]constant-value
```
When you don’t have a " * " what’s accepted is:
```
brasl 1,func is allowed (MCSymbolRef type)
brasl 1,func+4 is allowed (MCBinary type)
brasl 1,4+func is allowed (MCBinary type)
brasl 1,-4+func is allowed (MCBinary type)
brasl 1,func-4 is allowed (MCBinary type)
brasl 1,*func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+func+4 is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*+4+func is not allowed (* cannot be used for non-MCConstantExprs)
brasl 1,*-4+8+func is not allowed (* cannot be used for non-MCConstantExprs)
```
Reviewed By: Kai
Differential Revision: https://reviews.llvm.org/D100987
Summary:
This patch implements the backend implementation of adding global variables
directly to the table of contents (TOC), rather than adding the address of the
variable to the TOC.
Currently, this patch will look for the "toc-data" attribute on symbols in the
IR, and then add those symbols to the TOC.
ATM, this is implemented for 32 bit AIX.
Reviewers: sfertile
Differential Revision: https://reviews.llvm.org/D101178
- Add new variantKinds for the symbol's variable offset and region handle
- Print the proper relocation specifier @gd in the asm streamer when emitting
the TC Entry for the variable offset for the symbol
- Fix the switch section failure between the TC Entry of variable offset and
region handle
- Put .__tls_get_addr symbol in the ProgramCodeSects with XTY_ER property
Reviewed by: sfertile
Differential Revision: https://reviews.llvm.org/D100956
- Currently, the "." (Dot) character, when not identifying an Identifier or a Constant, refers to the current PC (Program Counter)
- However, in z/OS, for the HLASM dialect, it strictly accepts only the "*" as the current PC (Support for this will be put up in a follow-up patch)
- The changes in this patch allow individual platforms to choose whether they would like to use the "." (Dot) character as a marker for the current PC or not.
- It is achieved by introducing a new field in MCAsmInfo.h called `DotIsPC` (similar to `DollarIsPC`)
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D100975
- Previously, https://reviews.llvm.org/D99889 changed the framework in the AsmLexer to treat special tokens, if they occur at the start of the string, as Identifiers.
- These are used by the MASM Parser implementation in LLVM, and we can extend some of the changes made in the previous patch to SystemZ.
- In SystemZ, the special "tokens" referred to here are "_", "$", "@", "#". [_|$|@|#] are already supported as "part" of an Identifier.
- The changes in this patch ensure that these special tokens, when they occur at the start of the Identifier, are treated as Identifiers.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D100959
The .file directive is changed to only have basename in D36018 for
ELF.
But on AIX, we require the .file directive to also contain the
directory info. This aligns with other AIX compiler like XLC and is
required by some AIX tool like DBX.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D99785
- Previously, https://reviews.llvm.org/D72680 introduced a new attribute called `AllowSymbolAtNameStart` (in relation to the MAsmParser changes) in `MCAsmInfo.h` which (according to the comment in the header) allows the following behaviour:
```
/// This is true if the assembler allows $ @ ? characters at the start of
/// symbol names. Defaults to false.
```
- However, the usage of this field in AsmLexer.cpp doesn't seem completely accurate* for a couple of reasons.
```
default:
if (MAI.doesAllowSymbolAtNameStart()) {
// Handle Microsoft-style identifier: [a-zA-Z_$.@?][a-zA-Z0-9_$.@#?]*
if (!isDigit(CurChar) &&
isIdentifierChar(CurChar, MAI.doesAllowAtInName(),
AllowHashInIdentifier))
return LexIdentifier();
}
```
1. The Dollar and At tokens, when occurring at the start of the string, are treated as separate tokens (AsmToken::Dollar and AsmToken::At respectively) and not lexed as an Identifier.
2. I'm not too sure why `MAI.doesAllowAtInName()` is used when `AllowAtInIdentifier` could be used. For X86 platforms, afaict, this shouldn't be an issue, since the `CommentString` attribute isn't "@". (alternatively the call to the setter can be set anywhere else as needed). The `AllowAtInName` does have an additional important meaning, but in the context of AsmLexer, shouldn't mean anything different compared to `AllowAtInIdentifier`
My proposal is the following:
- Introduce 3 new fields called `AllowQuestionTokenAtStartOfString`, `AllowDollarTokenAtStartOfString` and `AllowAtTokenAtStartOfString` in MCAsmInfo.h which will encapsulate the previously documented behaviour of "allowing $, @, ? characters at the start of symbol names")
- Introduce these fields where "$", "@" are lexed, and treat them as identifiers depending on whether `Allow[Dollar|At]TokenAtStartOfString` is set.
- For the sole case of "?", append it to the existing logic for treating a "default" token as an Identifier.
z/OS (HLASM) will also make use of some of these fields in follow up patches.
completely accurate* - This was based on the comments and the intended behaviour the code. I might have completely misinterpreted it, and if that is the case my sincere apologies. We can close this patch if necessary, if there are no changes to be made :)
Depends on https://reviews.llvm.org/D99374
Reviewed By: Jonathan.Crowther
Differential Revision: https://reviews.llvm.org/D99889
- Add support for HLASM style integers. These are the decimal integers [0-9].
- HLASM does not support the additional prefixed integers like, `0b`, `0x`, octal integers and Masm style integers.
- To achieve this, a field `LexHLASMStyleIntegers` (similar to the `LexMasmStyleIntegers` field) is introduced in `MCAsmLexer.h` as well as a corresponding setter.
Note: This field could also go into MCAsmInfo.h. I used the previous precedent set by the `LexMasmIntegers` field.
Depends on https://reviews.llvm.org/D99286
Reviewed By: epastor
Differential Revision: https://reviews.llvm.org/D99374
- Currently, MCAsmInfo provides a CommentString attribute, that various targets can set, so that the AsmLexer can appropriately lex a string as a comment based on the set value of the attribute.
- However, AsmLexer also supports a few additional comment syntaxes, in addition to what's specified as a CommentString attribute. This includes regular C-style block comments (/* ... */), regular C-style line comments (// .... ) and #. While I'm not sure as to why this behaviour exists, I am assuming it does to maintain backward compatibility with GNU AS (see https://sourceware.org/binutils/docs/as/Comments.html#Comments for reference)
For example:
Consider a target which sets the CommentString attribute to '*'.
The following strings are all lexed as comments.
```
"# abc" -> comment
"// abc" -> comment
"/* abc */ -> comment
"* abc" -> comment
```
- In HLASM however, only "*" is accepted as a comment string, and nothing else.
- To achieve this, an additional attribute (`AllowAdditionalComments`) has been added to MCAsmInfo. If this attribute is set to false, then only the string specified by the CommentString attribute is used as a possible comment string to be lexed by the AsmLexer. The regular C-style block comments, line comments and "#" are disabled. As a final note, "#" will still be treated as a comment, if the CommentString attribute is set to "#".
Depends on https://reviews.llvm.org/D99277
Reviewed By: abhina.sreeskantharajan, myiwanch
Differential Revision: https://reviews.llvm.org/D99286
The GNU AS manual states the following about single-character constants enclosed within single quotes:
> Some backslash escapes apply to characters, \b, \f, \n, \r, \t, and \" with the same meaning as for strings, plus \' for a single quote.
Add two more characters to the switch handling this case to match GAS behaviour, plus a test to make sure nothing regresses.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99609
Use report_fatal_error here since this is an internal error, and not
something the user can/should be trying to fix.
Also distinguish between the symbol being missing and the symbol having
the wrong type.
We have a failure internally where the symbol is missing. Currently
trying to reduce the test case to something we can attach to an llvm
bug.
Differential Revision: https://reviews.llvm.org/D99960
This patch adds support for TLS variables to the XCOFF object writer:
- Add TData and TBSS sections
- Add CsectGroups for the mapping classes XCOFF::XMC_TL and XCOFF::XMC_UL
- Add XMC_UL in the enum entry of CsectStorageMapping class to print the string
while reading the symbol properties for TLS variables
- Fix the starting address of TData and TBSS sections
Reviewed by: hubert.reinterpretcast, DiggerLin
Differential Revision: https://reviews.llvm.org/D98946
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.
Solution:
This patch adds two new flags
- OF_CRLF which indicates that CRLF translation is used.
- OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.
Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.
So this is the behaviour per platform with my patch:
z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode
Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return
The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
if (Flags & OF_CRLF)
CrtOpenFlags |= _O_TEXT;
```
These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99426
These look like $00A0cf for hex and %001010101 for binary. They are used in Motorola assembly syntax.
Differential Revision: https://reviews.llvm.org/D98519
Define -fatal-warnings to make warnings fatal, and accept /WX as an ML.EXE compatible alias for it.
Also make sure that if Warning() returns true, we always treat it as an error.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92504
Make variables and text-macro references case-insensitive, to match ml.exe.
Also improve error handling for text-macro expansion.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D92503
- This patch adds in support to accept the "#" character as part of an Identifier.
- This support is needed especially for the HLASM dialect since "#" is treated as part of the valid "Alphabet" range
- The way this is done is by making use of the previous precedent set by the `AllowAtInIdentifier` field in `MCAsmLexer.h`. A new field called `AllowHashInIdentifier` is introduced.
- The static function `IsIdentifierChar` is also updated to accept the `#` character if the `AllowHashInIdentifier` field is set to true.
Note: The field introduced in `MCAsmLexer.h` could very well be moved to `MCAsmInfo.h`. I'm not opposed to it. I decided to put it in `MCAsmLexer` since there seems to be some sort of precedent already with `AllowAtInIdentifier`.
Reviewed By: abhina.sreeskantharajan, nickdesaulniers, MaskRay
Differential Revision: https://reviews.llvm.org/D99277
- https://reviews.llvm.org/rGb605cfb336989705f391d255b7628062d3dfe9c3 was reverted due to sanitizer bugs in the introduced unit-test (specifically in the Address sanitizer https://lab.llvm.org/buildbot/#/builders/5/builds/5697)
- This patch attempts to rectify that, as well as re-factor parts of the test
- The issue was previously, within the `setupCallToAsmParser` function in the unit-test, `SrcMgr` was declared as a local variable. `SrcMgr` owns a unique pointer. Since the variable goes out of scope at the end of the function, the unique pointer is released.
- This patch, moves the declaration of the `SrcMgr` variable to a class field, since the scope will remain until the class's destructor is invoked (which in this case is at the end of the unit test)
- Furthermore, this patch also moves the `MCContext Ctx` declaration from a local variable instance inside a function, to a unique pointer class field. This ensures the instantiation of the MCContext remains until the tear down of the test.
Reviewed By: abhina.sreeskantharajan
Differential Revision: https://reviews.llvm.org/D99004
This commit adds a full WasmTableType to MCSymbolWasm, differing from
the current situation (just an ElemType) in that it additionally records
a WasmLimits.
We add support for specifying the limits in .S files also, via the
following syntax variations:
.tabletype SYM, ELEMTYPE
.tabletype SYM, ELEMTYPE, MINSIZE
.tabletype SYM, ELEMTYPE, MINSIZE, MAXSIZE
Depends on D99186.
Differential Revision: https://reviews.llvm.org/D99191
This patch renames the "Initial" member of WasmLimits to the name used
in the spec, "Minimum".
In the core WebAssembly specification, the Limits data type has one
required "min" member and one optional "max" member, indicating the
minimum required size of the corresponding table or memory, and the
maximum size, if any.
Although the WebAssembly spec does instantiate locally-defined tables
and memories with the initial size being equal to the minimum size, it
can't impose such a requirement for imports. It doesn't make sense to
require an initial size for a memory import, for example. The compiler
can only sensibly express the minimum and maximum sizes.
See
https://github.com/WebAssembly/js-types/blob/master/proposals/js-types/Overview.md#naming-of-size-limits
for a related discussion that agrees that the right name of "initial" is
"minimum" when querying the type of a table or memory from JavaScript.
(Of course it still makes sense for JS to speak in terms of an initial
size when it explicitly instantiates memories and tables.)
Differential Revision: https://reviews.llvm.org/D99186
This is the alternative approach to D96931.
In LTO, for each module with inlineasm block, prepend directive ".lto_discard <sym>, <sym>*" to the beginning of the inline
asm. ".lto_discard" is both a module inlineasm block marker and (optionally) provides a list of symbols to be discarded.
In MC while emitting for inlineasm, discard symbol binding & symbol
definitions according to ".lto_disard".
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D98762
- Previously, https://reviews.llvm.org/D97703 was [[ https://reviews.llvm.org/D98543 | reverted ]] as it broke when building the unit tests when shared libs on.
- This patch reverts the "revert" and makes two minor changes
- The first is it also links in the MCParser lib when building the unittest. This should resolve the issue when building with with shared libs on and off
- The second renames the name of the unit test from `SystemZAsmLexer` to `SystemZAsmLexerTests` since the convention for unittest binaries is to suffix the name of the unit test with "Tests"
Reviewed By: Kai
Differential Revision: https://reviews.llvm.org/D98666
- This patch adds in support for the ordinary HLASM comment syntax asm
statements (Reference - Chapter 7, Comment Statements, Ordinary Comment
Statements)
- In brief, the ordinary comment syntax if used, must begin with the "*"
character
- To achieve this, this patch makes use of the CommentString attribute
provided in the base MCAsmInfo class
- In the SystemZMCAsmInfo class, the CommentString attribute was set to
"*" based on the assembler dialect
- Furthermore, a new attribute RestrictCommentString, is provided to only
treat a string as a comment if it appears at the start of the asm
statement. Example: "jo *-4" is valid in HLASM (jump back 4 bytes from
current point - similar to jo -4 in gnu asm) and we don't want "*-4" to
be treated as a comment.
- RFC for HLASM Parser support implementation: https://lists.llvm.org/pipermail/llvm-dev/2021-January/147686.html
Reviewed By: scott.linder, Kai
Differential Revision: https://reviews.llvm.org/D97703
Summary: This is a minor patch to add names for the debug line prologue, as a follow-up of D95998.
Reviewed By: dblaikie, ikudrin, shchenz
Differential Revision: https://reviews.llvm.org/D98383
A symbol being redefined as a label is something that can happen as a result of
ordinary input, so it shouldn't cause a fatal error. Also adjust the error
message to match the one you get when a symbol is redefined as a variable.
Differential Revision: https://reviews.llvm.org/D98181
This `R_WASM_MEMORY_ADDR_SELFREL_I32` relocation represents an offset
between its relocating address and the symbol address. It's very similar
to `R_X86_64_PC32` but restricted to be used for only data segments.
```
S + A - P
```
A: Represents the addend used to compute the value of the relocatable
field.
P: Represents the place of the storage unit being relocated.
S: Represents the value of the symbol whose index resides in the
relocation entry.
Proposal: https://github.com/WebAssembly/tool-conventions/issues/162
Differential Revision: https://reviews.llvm.org/D96659
For many directives, the following diagnostics
* `error: unexpected token`
* `error: unexpected token in '.abort' directive"`
are replaced with `error: expected newline`.
`unexpected token` may make the user think a different token is needed.
`expected newline` is clearer about the expected token.
For `in '...' directive`, the directive name is not useful because the next line
replicates the error line which includes the directive.
As a resolution to https://sourceware.org/bugzilla/show_bug.cgi?id=25295 , GNU as
from binutils 2.35 supports the optional third argument for the .symver directive.
'remove' for a non-default version is useful:
`.symver def_v1, def@v1, remove` => def_v1 is not retained in the symbol table.
Previously the user has to strip the original symbol or specify a `local:`
version node in a version script to localize the symbol.
`.symver def, def@@v1, remove` and `.symver def, def@@@v1, remove` are supported
as well, though they are identical to `.symver def, def@@@v1`.
local/hidden are not useful so this patch does not implement them.
With reference types, tables can have non-zero table numbers. This
commit adds support for element sections against these tables.
Differential Revision: https://reviews.llvm.org/D97923
This patch allows generating TLS variables in assembly files on AIX.
Initialized and external uninitialized variables are generated with the
.csect pseudo-op and local uninitialized variables are generated with
the .comm/.lcomm pseudo-ops. The patch also adds a check to
explicitly say that TLS is not yet supported on AIX.
Reviewed by: daltenty, jasonliu, lei, nemanjai, sfertile
Originally patched by: bsaleil
Commandeered by: NeHuang
Differential Revision: https://reviews.llvm.org/D96184
The situation with inline asm/MC error reporting is kind of messy at the
moment. The errors from MC layout are not reliably propagated and users
have to specify an inlineasm handler separately to get inlineasm
diagnose. The latter issue is not a correctness issue but could be improved.
* Kill LLVMContext inlineasm diagnose handler and migrate it to use
DiagnoseInfo/DiagnoseHandler.
* Introduce `DiagnoseInfoSrcMgr` to diagnose SourceMgr backed errors. This
covers use cases like inlineasm, MC, and any clients using SourceMgr.
* Move AsmPrinter::SrcMgrDiagInfo and its instance to MCContext. The next step
is to combine MCContext::SrcMgr and MCContext::InlineSrcMgr because in all
use cases, only one of them is used.
* If LLVMContext is available, let MCContext uses LLVMContext's diagnose
handler; if LLVMContext is not available, MCContext uses its own default
diagnose handler which just prints SMDiagnostic.
* Change a few clients(Clang, llc, lldb) to use the new way of reporting.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D97449
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via TABLE_NUMBER
relocations against a table symbol.
Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.
Differential Revision: https://reviews.llvm.org/D90948
Use emitDwarfUnitLength for debug line, so we can benefit from
overriding of emitDwarfUnitLength inside different streamers.
Reviewed By: ikudrin, dblaikie
Differential Revision: https://reviews.llvm.org/D95998
GNU as supports this. This mode silently ignores
.cfi_startproc/.cfi_endproc and .cfi_* in between.
Also drop a diagnostic `in '.cfi_sections' directive`: the diagnostic
already includes the line and it is clear the line is a `.cfi_sections` directive.
remove `Hi` `Lo` argument from `emitDwarfUnitLength`, so we
can make caller of emitDwarfUnitLength easier.
Reviewed By: MaskRay, dblaikie, ikudrin
Differential Revision: https://reviews.llvm.org/D96409
This is for XCOFF DWARF support.
Seems when DWARF debug is enable, symbol 0 has special usage
for AIX binder. At least, symbol 0 can not be the .text
section. Otherwise, we get some binding time error.
Add correct C_FILE symbol at index 0 here to make AIX binder
work.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D97117
We may need to do some customization for DWARF unit length in DWARF
section headers for some targets for some code generation path.
For example, for XCOFF in assembly path, AIX assembler does not require
the debug section containing its debug unit length in the header.
Move emitDwarfUnitLength to MCStreamer class so that we can do
customization in different Streamers
Reviewed By: ikudrin
Differential Revision: https://reviews.llvm.org/D95932
If the reference-types feature is enabled, call_indirect will explicitly
reference its corresponding function table via `TABLE_NUMBER`
relocations against a table symbol.
Also, as before, address-taken functions can also cause the function
table to be created, only with reference-types they additionally cause a
symbol table entry to be emitted.
We abuse the used-in-reloc flag on symbols to indicate which tables
should end up in the symbol table. We do this because unfortunately
older wasm-ld will carp if it see a table symbol.
Differential Revision: https://reviews.llvm.org/D90948
Fixes assert in: https://bugs.llvm.org/show_bug.cgi?id=49036
getWasmSection creates sections if they don't exist, but doesn't add them to the Symbols table. This may cause problems in subsequent calls to getOrCreateSymbol which checks this table, the calls createSymbol assuming it doesn't exist, which then checks UsedNames and finds out it does exist, causing an assert on trying to rename a non-temp symbol.
I tried also fixing the somewhat unintuitive forced suffixing (adding `0`), but it turns out that WasmObjectWriter currently assumes these section symbols are unique, so that may have to be a separate fix: https://bugs.llvm.org/show_bug.cgi?id=49252
Also worth noting is that getWasmSection calling createSymbol may not be correct to start with, given that createSymbol seems to assume it is creating non-section symbols. But again, for a future fix.
Related: where some of this was introduced: 8d396acac3
Differential Revision: https://reviews.llvm.org/D96473
This patch makes StorageMappingClass/SymbolType member optional in
class MCSectionXCOFF.
Non-csect sections like debug sections have no such properties.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D96641
We are going to support debug sections for XCOFF. So the csect
properties are not necessary. This patch makes these properties
optional.
Reviewed By: hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D95931
This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF section groups. These are generally useful to enable linker GC
where you want a group of sections to always travel together, that is to
be either retained or discarded as a whole, but without the COMDAT
semantics. Other ELF assemblers already support zero flag ELF section
groups and this change helps us reach feature parity.
Differential Revision: https://reviews.llvm.org/D95851
In the future Windows will enable Control-flow Enforcement Technology (CET aka shadow stacks). To protect the path where the context is updated during exception handling, the binary is required to enumerate valid unwind entrypoints in a dedicated section which is validated when the context is being set during exception handling.
This change allows llvm to generate the section that contains the appropriate symbol references in the form expected by the msvc linker.
This feature is enabled through a new module flag, ehcontguard, which was modelled on the cfguard flag.
The change includes a test that when the module flag is enabled the section is correctly generated.
The set of exception continuation information includes returns from exceptional control flow (catchret in llvm).
In order to collect catchret we:
1) Includes an additional flag on machine basic blocks to indicate that the given block is the target of a catchret operation,
2) Introduces a new machine function pass to insert and collect symbols at the start of each block, and
3) Combines these targets with the other EHCont targets that were already being collected.
Change originally authored by Daniel Frampton <dframpto@microsoft.com>
For more details, see MSVC documentation for `/guard:ehcont`
https://docs.microsoft.com/en-us/cpp/build/reference/guard-enable-eh-continuation-metadata
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D94835
As we don't sort local symbols, don't sort non-local symbols. This makes
non-local symbols appear in their register order, which matches GNU as. The
register order is nice in that you can write tests with interleaved CHECK
prefixes, e.g.
```
// CHECK: something about foo
.globl foo
foo:
// CHECK: something about bar
.globl bar
bar:
```
With the lexicographical order, the user needs to place lexicographical smallest
symbol first or keep CHECK prefixes in one place.
This allows data sections that don't start with `.data` to be
used/created.
Without this, clang's `__attribute__((section("foo")))` would
generate assembly that would not parse.
Differential Revision: https://reviews.llvm.org/D96233
References to functions are in program memory and need a `pm()` fixup. This should fix trait objects for Rust on AVR.
Differential Revision: https://reviews.llvm.org/D87631
Patch by Alex Mikhalev.
When calculating the symbol offsets to write as provisitonal values
in object files we are only interested in the offset of the symbol
itself. For aliases this offset already includes the offset of the
base symbol.
The testin question was added back in https://reviews.llvm.org/D87407
but I believe the expectations here were incorrect. sym_a lives
at offset 4 and sym_b lives 4 bytes into that (should be 8).
The addresses of the 3 symbosl in this object file are:
foo : 0
sym_a: 4
sym_b: 8
Differential Revision: https://reviews.llvm.org/D96234
GNU as does not sort local symbols. This has several advantages:
* The .symtab order is roughly the symbol occurrence order.
* The closest preceding STT_SECTION symbol is the definition of a local symbol.
* The closest preceding STT_FILE symbol is the defining file of a local symbol, if there are multiple default-version .file directives. (Not implemented in MC.)
As mentioned in TODO comment, casting double to float causes NaNs to change bits.
To avoid the change, this patch adds support for single-floating-point immediate value on MachineCode.
Patch by Yuta Saito.
Differential Revision: https://reviews.llvm.org/D77384
Without `-dwarf-version`, llvm-mc uses the default `MCContext::DwarfVersion` 4.
Without `-gdwarf-N`, Clang cc1as uses `clang::driver::ToolChain::GetDefaultDwarfVersion`
which is 4 on many toolchains. Note: `clang -c` can synthesize .debug_info without -g.
There is currently a MCParser warning upon `.file 0` and MCParser errors upon
`.loc 0` if the DWARF version is less than 5. This causes friction to the
following usage:
```
clang -S -g -gdwarf-5 a.c
// MC warning due to .file 0, MC error due to .loc 0
clang -c a.s
llvm-mc -filetype=obj a.s
```
My idea is that we can just upgrade `MCContext::DwarfVersion` to 5 upon
`.file 0` to make the above commands work.
The downside is that for an explicit version `clang -c -gdwarf-4 a.s`, it can be
argued that the new behavior drops the probably intended diagnostic. I think the
downside is small because in most cases DWARF version for an assembly action
should either match the original compile action or be omitted.
Ongoing discussion taking a similar action for GNU as: https://sourceware.org/pipermail/binutils/2021-January/114980.html
Differential Revision: https://reviews.llvm.org/D94882
On Linux target triples, GNU as sets EI_OSABI to ELFOSABI_GNU when SHF_GNU_RETAIN is used。
On `*-*-freebsd`, it usually sets EI_OSABI to ELFOSABI_FREEBSD.
GNU ld respects SHF_GNU_RETAIN only for ELFOSABI_FREEBSD/ELFOSABI_GNU.
https://sourceware.org/bugzilla/show_bug.cgi?id=27282
MC doesn't set ELFOSABI_GNU for SHF_GNU_RETAIN/STB_GNU_UNIQUE/STT_GNU_IFUNC.
MC assembled object files do not have special semantics in GNU ld.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D95730
Followup to D92052 as I missed an issue as shown via GCC bug https://gcc.gnu.org/PR97827, namely: (e.g.) ".rodata." implies ELF::SHF_ALLOC.
Crossref:
- D73999 / commit 75af9da755
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
- D92052 / commit 1deff4009e
permitted the abbreviated form which many assemblers accept and
GCC generates: while the first .section contains the flags and entsize,
subsequent sections simply contain the name without repeating entsize or
flags.
However, the latter patch missed in the check that some flags are automatically set, e.g. '.rodata." implies ELF::SHF_ALLOC.
Related https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D94072
This reverts commit d806618636.
Review: https://reviews.llvm.org/D92215
We had issues where older versions of wasm-ld were crashing on object
files containing a table symbol. We decided that the best strategy
going forward is to only generate these symbol if refernece types is
enabled. Without reference types enabled we should never geneate a
table symbol or a TABLE_NUMBER relocation.
This revert is in addition to the one already reverted in
https://reviews.llvm.org/D95005.
The plan is to re-land these in updated form after the llvm 12 branch.
Differential Revision: https://reviews.llvm.org/D95420
This reverts commit 418df4a6ab.
This change broke emscripten tests, I believe because it started
generating 5-byte a wide table index in the call_indirect instruction.
Neither v8 nor wabt seem to be able to handle that. The spec
currently says that this is single 0x0 byte and:
"In future versions of WebAssembly, the zero byte occurring in the
encoding of the call_indirectcall_indirect instruction may be used to
index additional tables."
So we need to revisit this change. For backwards compat I guess
we need to guarantee that __indirect_function_table is always at
address zero. We could also consider making this a single-byte
relocation with and assert if have more than 127 tables (for now).
Differential Revision: https://reviews.llvm.org/D95005
Element sections will also need flags, so we shouldn't squat the
WASM_SEGMENT namespace.
Depends on D90948.
Differential Revision: https://reviews.llvm.org/D92315
This patch changes to make call_indirect explicitly refer to the
corresponding function table, residualizing TABLE_NUMBER relocs against
it.
With this change, wasm-ld now sees all references to tables, and can
link multiple tables.
Differential Revision: https://reviews.llvm.org/D90948
Now that the linker handles table symbols, we can allow the frontend to
produce them.
Depends on D91870.
Differential Revision: https://reviews.llvm.org/D92215
Now that the linker handles table symbols, we can allow the frontend to
produce them.
Depends on D91870.
Differential Revision: https://reviews.llvm.org/D92215
Be consistent about asserting before setting WasmIndices. Adding
these assertions revealed that we were duplicating a lot of work
and setting these indexed twice when running in DWO mode.
Differential Revision: https://reviews.llvm.org/D93650
For wasm-ld table linking work to proceed, object files should indicate
if they use an indirect function table. In the future this will be done
by the usual symbols and relocations mechanism, but until that support
lands in the linker, the presence of an `__indirect_function_table` in
the object file's import section shows that the object file needs an
indirect function table.
Prior to https://reviews.llvm.org/D91637, this condition was met by all
object files residualizing an `__indirect_function_table` import.
Since https://reviews.llvm.org/D91637, the intention has been that only
those object files needing an indirect function table would have the
`__indirect_function_table` import. However, we missed the case of
object files which use the table via `call_indirect` but which
themselves do not declare any indirect functions.
This changeset makes it so that when we lower a call to `call_indirect`,
that we ensure that a `__indirect_function_table` symbol is present and
that it will be propagated to the linker.
A followup patch will revise this mechanism to make an explicit link
between `call_indirect` and its associated indirect function table; see
https://reviews.llvm.org/D90948.
Differential Revision: https://reviews.llvm.org/D92840
CanBeUnnamed is rarely false. Splitting to a createNamedTempSymbol makes the
intention clearer and matches the direction of reverted r240130 (to drop the
unneeded parameters).
No behavior change.
Errors from MCAssembler, MCObjectStreamer and *ObjectWriter typically cause a crash:
```
% cat c.c
int bar;
extern int foo __attribute__((alias("bar")));
% clang -c -fcommon c.c
fatal error: error in backend: Common symbol 'bar' cannot be used in assignment expr
PLEASE submit a bug report to ...
Stack dump:
...
```
`LLVMTargetMachine::addPassesToEmitFile` constructs `MachineModuleInfoWrapperPass`
which creates a MCContext without SourceMgr. `MCContext::reportError` calls
`report_fatal_error` which gets captured by Clang `LLVMErrorHandler` and gets translated
to the output above.
Since `MCContext::reportError` errors indicate user errors, such a crashing style error
is inappropriate. So this patch changes `report_fatal_error` to `SourceMgr().PrintMessage`.
```
% clang -c -fcommon c.c
<unknown>:0: error: Common symbol 'bar' cannot be used in assignment expr
```
Ideally we should at least recover the original filename (the line information
is generally lost). That requires general improvement to MC diagnostics,
because currently in many cases SMLoc information is lost.
Currently the integrated assembler only allows commas as the separator
between string arguments in .ascii. This patch adds support to using
space as separators and make IAS consistent with GNU assembler.
Link: https://github.com/ClangBuiltLinux/linux/issues/1196
Reviewed By: nickdesaulniers, jrtc27
Differential Revision: https://reviews.llvm.org/D91460
This relands D64327 with a more specific workaround for R_386_GOTOFF
(gold<2.34 bug https://sourceware.org/bugzilla/show_bug.cgi?id=16794)
.debug_info has quite a few .debug_str relocations (R_386_32/R_ARM_ABS32).
The original workaround was too general and introduced too many .L symbols
used just as relocation targets.
From the original review:
... it reduced the size of a big ARM-32 debug image by 33%. It contained ~68M
of relocations symbols out of total ~71M symbols (96% of symbols table was
generated for relocations with symbol).
This is consistent with the resolution to power-of-2 alignments.
Otherwise, emitCodeAlignment and emitValueToAlignment cannot handle alignments
larger than 2**32 and will trigger assertion failure (PR35218).
Note: GNU as as of 2.35 will use 1 for such a large byte `.align`
D73999 / commit 75af9da755
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.
However, GNU assembler accepts and GCC generates an abbreviated form:
while the first .section contains the flags and entsize, subsequent
sections simply contain the name without repeating entsize or flags.
Do likewise for better compatibility.
See https://bugs.llvm.org/show_bug.cgi?id=48201
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D92052
This change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s
Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections. The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead.
**ELF object emission**
The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.
Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication. A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.
**Assembling**
Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.
A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.
A example assembly looks like:
```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```
With inlining turned on, the assembly may look different around %bb2 with an inlined probe:
```
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 3 0
.pseudoprobe 6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe 837061429793323041 4 0
popq %rax
retq
```
**Disassembling**
We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.
An example disassembly looks like:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D91878
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
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 change implements pseudo probe encoding and emission for CSSPGO. Please see RFC here for more context: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s
Pseudo probes are in the form of intrinsic calls on IR/MIR but they do not turn into any machine instructions. Instead they are emitted into the binary as a piece of data in standalone sections. The probe-specific sections are not needed to be loaded into memory at execution time, thus they do not incur a runtime overhead.
**ELF object emission**
The binary data to emit are organized as two ELF sections, i.e, the `.pseudo_probe_desc` section and the `.pseudo_probe` section. The `.pseudo_probe_desc` section stores a function descriptor for each function and the `.pseudo_probe` section stores the actual probes, each fo which corresponds to an IR basic block or an IR function callsite. A function descriptor is stored as a module-level metadata during the compilation and is serialized into the object file during object emission.
Both the probe descriptors and pseudo probes can be emitted into a separate ELF section per function to leverage the linker for deduplication. A `.pseudo_probe` section shares the same COMDAT group with the function code so that when the function is dead, the probes are dead and disposed too. On the contrary, a `.pseudo_probe_desc` section has its own COMDAT group. This is because even if a function is dead, its probes may be inlined into other functions and its descriptor is still needed by the profile generation tool.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
To support building a context-sensitive profile, probes from inlinees are grouped by their inline contexts. An inline context is logically a call path through which a callee function lands in a caller function. The probe emitter builds an inline tree based on the debug metadata for each outlined function in the form of a trie tree. A tree root is the outlined function. Each tree edge stands for a callsite where inlining happens. Pseudo probes originating from an inlinee function are stored in a tree node and the tree path starting from the root all the way down to the tree node is the inline context of the probes. The emission happens on the whole tree top-down recursively. Probes of a tree node will be emitted altogether with their direct parent edge. Since a pseudo probe corresponds to a real code address, for size savings, the address is encoded as a delta from the previous probe except for the first probe. Variant-sized integer encoding, aka LEB128, is used for address delta and probe index.
**Assembling**
Pseudo probes can be printed as assembly directives alternatively. This allows for good assembly code readability and also provides a view of how optimizations and pseudo probes affect each other, especially helpful for diff time assembly analysis.
A pseudo probe directive has the following operands in order: function GUID, probe index, probe type, probe attributes and inline context. The directive is generated by the compiler and can be parsed by the assembler to form an encoded `.pseudoprobe` section in the object file.
A example assembly looks like:
```
foo2: # @foo2
# %bb.0: # %bb0
pushq %rax
testl %edi, %edi
.pseudoprobe 837061429793323041 1 0 0
je .LBB1_1
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 6 2 0
callq foo
.pseudoprobe 837061429793323041 3 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
.LBB1_1: # %bb1
.pseudoprobe 837061429793323041 5 1 0
callq *%rsi
.pseudoprobe 837061429793323041 2 0 0
.pseudoprobe 837061429793323041 4 0 0
popq %rax
retq
# -- End function
.section .pseudo_probe_desc,"",@progbits
.quad 6699318081062747564
.quad 72617220756
.byte 3
.ascii "foo"
.quad 837061429793323041
.quad 281547593931412
.byte 4
.ascii "foo2"
```
With inlining turned on, the assembly may look different around %bb2 with an inlined probe:
```
# %bb.2: # %bb2
.pseudoprobe 837061429793323041 3 0
.pseudoprobe 6699318081062747564 1 0 @ 837061429793323041:6
.pseudoprobe 837061429793323041 4 0
popq %rax
retq
```
**Disassembling**
We have a disassembling tool (llvm-profgen) that can display disassembly alongside with pseudo probes. So far it only supports ELF executable file.
An example disassembly looks like:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
Reviewed By: wmi
Differential Revision: https://reviews.llvm.org/D91878
There is an explicit option for the lexer to support this, but we crash
when `-preserve-comments` is enabled because it checks for
`getTok().getString().empty()` to detect the case. This doesn't
work currently because the lexer reports this case as a string of length
1, containing a null byte.
Change the lexer to instead report this case via an empty string, as the
null terminator isn't logically a part of the textual input, and the
check for `.empty()` seems natural and obvious in the calling code.
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D92681
Allow sections to be placed into COMDAT groups, in addtion to functions and data
segments.
Also make section symbols unnamed, which allows sections with identical names
(section names are independent of their section symbols, but previously we
gave the symbols the same name as their sections, which results in collisions
when sections are identically-named).
Differential Revision: https://reviews.llvm.org/D92691
Notes:
* llvm::createAsmStreamer: it has been moved to TargetRegistry.h
* (anon ns)::WasmObjectWriter::updateCustomSectionRelocations: remnant of D46335
* COFFAsmParser::ParseSEHRegisterNumber: remnant of D66625
* llvm::CodeViewContext::isValidCVFileNumber: accidentally added by r279847
Previously these directives were always interpreted as having an extra
blank line after them.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D92612
Summary:
Not all system assembler supports `.uleb128 label2 - label1` form.
When the target do not support this form, we have to take
alternative manual calculation to get the offsets from them.
Reviewed By: hubert.reinterpretcast
Diffierential Revision: https://reviews.llvm.org/D92058
Summary:
AIX uses the existing EH infrastructure in clang and llvm.
The major differences would be
1. AIX do not have CFI instructions.
2. AIX uses a new personality routine, named __xlcxx_personality_v1.
It doesn't use the GCC personality rountine, because the
interoperability is not there yet on AIX.
3. AIX do not use eh_frame sections. Instead, it would use a eh_info
section (compat unwind section) to store the information about
personality routine and LSDA data address.
Reviewed By: daltenty, hubert.reinterpretcast
Differential Revision: https://reviews.llvm.org/D91455
Currently, `llvm_bb_addr_map` sections are generated per section names because we use
the `LinkedToSymbol` argument of getELFSection. This will cause the address map tables of functions
grouped into the same section when `-function-sections=true -unique-section-names=false` which is not
the intended behaviour. This patch lets the unique id of every `.text` section propagate to the associated
`.llvm_bb_addr_map` section.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D92113
If prefaced with a %, expand text macros and macro functions in any statement.
Also, prevent expanding text macros in the message of an ECHO directive unless expanded explicitly by the statement expansion operator.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89740
Similar to D92113. Currently `clang -fstack-size-section -fno-unique-section-names`
sets the linked-to symbol to the first `.text`, which is:
* incorrect for COMDAT sections
* inferior for non-COMDAT sections in -ffunction-sections mode (poor --gc-sections: .stack_sizes cannot be separately discarded)
Note, if the section symbol can be referenced in more places (if the
function begin symbol does not apply), we probably should consider
defining a different BeginSymbol for sections with ",unique" linkage.
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D92151
In text-item contexts, %expr expands to a string containing the results of evaluating `expr`.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89736
The indirect function table, synthesized by the linker, is needed if and
only if there are TABLE_INDEX relocs.
Differential Revision: https://reviews.llvm.org/D91637
This commit factors out a WasmTableType definition from WasmTable, as is
the case for WasmGlobal and other data types. Also add support for
extracting the SymbolName for a table from the linking section's symbol
table.
Differential Revision: https://reviews.llvm.org/D91849
This reapplies 36c64af9d7 in updated
form.
Emit the xdata for each function at .seh_endproc. This keeps the
exact same output header order for most code generated by the LLVM
CodeGen layer. (Sections still change order for code built from
assembly where functions lack an explicit .seh_handlerdata
directive, and functions with chained unwind info.)
The practical effect should be that assembly output lacks
superfluous ".seh_handlerdata; .text" pairs at the end of functions
that don't handle exceptions, which allows such functions to use
the AArch64 packed unwind format again.
Differential Revision: https://reviews.llvm.org/D87448
Accept macro function definitions, and apply them when invoked in operand position.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89734
2c196bbc6b asserted that
`SmallVector::push_back` doesn't invalidate the parameter when it needs
to grow. Do the same for `resize`, `append`, `assign`, `insert`, and
`emplace_back`.
Differential Revision: https://reviews.llvm.org/D91744
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4acf8c78e659833be8be047ba2f8561386a11d4b
(1994) introduced this behavior:
if a fixup symbol is equated to an expression with an undefined symbol, convert
the fixup to be against the target symbol. glibc relies on this behavior to perform
assembly level indirection
```
asm("memcpy = __GI_memcpy"); // from sysdeps/generic/symbol-hacks.h
...
// call memcpy@PLT
// The relocation references __GI_memcpy in GNU as, but memcpy in MC (without the patch)
memcpy (...);
```
(1) It complements `extern __typeof(memcpy) memcpy asm("__GI_memcpy");` The frontend asm label does not redirect synthesized memcpy in the middle-end. (See D88712 for details)
(2) `asm("memcpy = __GI_memcpy");` is in every translation unit, but the memcpy declaration may not be visible in the translation unit where memcpy is synthesized.
MC already redirects `memcpy = __GI_memcpy; call memcpy` but not `memcpy = __GI_memcpy; call memcpy@plt`.
This patch fixes the latter by allowing MCExpr::evaluateAsRelocatableImpl to
evaluate a non-VK_None MCSymbolRefExpr, which is only done after the layout is available.
GNU as allows `memcpy = __GI_memcpy+1; call memcpy@PLT` which seems nonsensical, so we don't allow it.
`MC/PowerPC/pr38945.s` `NUMBER = 0x6ffffff9; cmpwi 8,NUMBER@l` requires the
`symbol@l` form in AsmMatcher, so evaluation needs to be deferred. This is the
place whether future simplification may be possible.
Note, if we suppress the VM_None evaluation when MCAsmLayout is nullptr, we may
lose the `invalid reassignment of non-absolute variable` diagnostic
(`ARM/thumb_set-diagnostics.s` and `MC/AsmParser/variables-invalid.s`).
We know that this diagnostic is troublesome in some cases
(https://github.com/ClangBuiltLinux/linux/issues/1008), so we can consider
making simplification in the future.
Reviewed By: jyknight
Differential Revision: https://reviews.llvm.org/D88625
This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D87544
This patch uses the new `getMnemonic` helper from D90039
to display mnemonics instead of the internal opcodes.
The main motivation behind using the mnemonics is that they
are more user-friendly and more directly related to the assembly
the users will be presented.
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D90040
These relocations represent offsets from the __tls_base symbol.
Previously we were just using normal MEMORY_ADDR relocations and relying
on the linker to select a segment-offset rather and absolute value in
Symbol::getVirtualAddress(). Using an explicit relocation type allows
allow us to clearly distinguish absolute from relative relocations based
on the relocation information alone.
One place this is useful is being able to reject absolute relocation in
the PIC case, but still accept TLS relocations.
Differential Revision: https://reviews.llvm.org/D91276
No longer rely on an external tool to build the llvm component layout.
Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.
These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.
Differential Revision: https://reviews.llvm.org/D90848
I was trying to add .cfi_ annotations to assembly code in the FreeBSD
kernel and changed a macro that then resulted in incorrectly nested
directives. However, clang's diagnostics said the error was happening at
<unknown>:0. This addresses one of the TODOs added in D51695.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D89787
This broke both Firefox and Chromium (PR47905) due to what seems like dllimport
function not being handled correctly.
> This patch adds support for creating Guard Address-Taken IAT Entry Tables (.giats$y sections) in object files, matching the behavior of MSVC. These contain lists of address-taken imported functions, which are used by the linker to create the final GIATS table.
> Additionally, if any DLLs are delay-loaded, the linker must look through the .giats tables and add the respective load thunks of address-taken imports to the GFIDS table, as these are also valid call targets.
>
> Reviewed By: rnk
>
> Differential Revision: https://reviews.llvm.org/D87544
This reverts commit cfd8481da1.
Support MASM's REPEAT, FOR, FORC, and WHILE macro-like directives.
Also adds support for macro argument substitution inside quoted strings, and additional testing for macro directives.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89732
MASM interprets strings in expression contexts as integers expressed in big-endian base-256, treating each character as its ASCII representation.
This completely eliminates the need to special-case single-character strings.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D90788
Makes sure that the unwind info uses 64bits pcrel relocation if a large code model is specified and handle the corresponding relocation in the ExecutionEngine. This can happen with certain kernel configuration (the same as the one in https://reviews.llvm.org/D27609, found at least on the ArchLinux stock kernel and the one used on https://www.packet.net/) using the builtin JIT memory manager.
Co-authored-by: Yichao Yu <yyc1992@gmail.com>
Differential Revision: https://reviews.llvm.org/D27629
Allow single-quoted strings and double-quoted character values, as well as doubled-quote escaping.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89731
Allows the MACRO directive to define macro procedures with parameters and macro-local symbols.
Supports required and optional parameters (including default values), and matches ml64.exe for its macro-local symbol handling (up to 65536 macro-local symbols in any translation unit).
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D89729
A SMLoc allows MCStreamer to report location-aware diagnostics, which
were previously done by adding SMLoc to various methods (e.g. emit*) in an ad-hoc way.
Since the file:line is most important, the column is less important and
the start token location suffices in many cases, this patch reverts
b7e7131af2
```
// old
symbol-binding-changed.s:6:8: error: local changed binding to STB_GLOBAL
.globl local
^
// new
symbol-binding-changed.s:6:1: error: local changed binding to STB_GLOBAL
.globl local
^
```
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D90511
If MCContext has an error, MCAssembler::layout may stop early
and some MCFragment's may not finalize.
In the Linux kernel, arch/x86/lib/memcpy_64.S could trigger the assert before
"x86_64: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S"
GNU as let .weak override .globl since binutils-gdb
5ca547dc2399a0a5d9f20626d4bf5547c3ccfddd (1996) while MC lets the last
directive win (PR38921).
This caused an issue to Linux's powerpc port which has been fixed by
http://git.kernel.org/linus/968339fad422a58312f67718691b717dac45c399
Binding overriding is error-prone. This patch disallows a changed binding.
(https://sourceware.org/pipermail/binutils/2020-March/000299.html )
Our behavior regarding `.globl x; .weak x` matches GNU as. Such usage is
still suspicious but we issue a warning for now. We may upgrade it to an
error in the future.
Reviewed By: jhenderson, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D90108
Since Wasm comdat sections work similarly to ELF, we can use that mechanism
to eliminate duplicate dwarf type information in the same way.
Differential Revision: https://reviews.llvm.org/D88603
Since Wasm comdat sections work similarly to ELF, we can use that mechanism
to eliminate duplicate dwarf type information in the same way.
Differential Revision: https://reviews.llvm.org/D88603
Implementation of instructions table.get, table.set, table.grow,
table.size, table.fill, table.copy.
Missing instructions are table.init and elem.drop as they deal with
element sections which are not yet implemented.
Added more tests to tables.s
Differential Revision: https://reviews.llvm.org/D89797
Kyungwoo Lee