For relocations against temporary symbols (that don't persist in
the object file), we normally adjust them to reference the start of
the section.
For adrp relocations, the immediate offset from the referenced
symbol is stored in the opcode as the 21 bit signed immediate; this
means that the symbol referenced must be within +/- 1 MB from the
referenced symbol.
Create label symbols with regular intervals (1 MB intervals). For
relocations against temporary symbols, pick the preceding added
offset symbol and make the relocation against that instead of
against the start of the section.
This should fix the root issue behind
https://bugs.llvm.org/show_bug.cgi?id=52378.
Differential Revision: https://reviews.llvm.org/D114340
For tagged-globals, we only need to disable relaxation for globals that
we actually tag. With this patch function pointer relocations, which
we do not instrument, can be relaxed.
This patch also makes tagged-globals work properly with LTO, as
-Wa,-mrelax-relocations=no doesn't work with LTO.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D113220
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
Zarko Todorovski