This requires being able to opt out from adding the leading underscores
in COFFModuleDefinition. Normally it is added automatically for I386
type targets. We could either move the decision entirely to all
callers, letting the caller check the machine type and decide whether
underscores should be added, or keep the logic mostly as is, but allowing
opting out from the behaviour on I386.
I went with keeping the interface as is for now.
Differential Revision: https://reviews.llvm.org/D152363
Summary:
In big archive , there is 32bit global symbol table and 64 bit global symbol table. llvm-ar only support 32bit global symbol table this moment, we need to support the 64 bit global symbol table.
https://www.ibm.com/docs/en/aix/7.2?topic=formats-ar-file-format-big
Global Symbol Tables
Immediately following the member table, the archive file contains two global symbol tables. The first global symbol table locates 32-bit file members that define global symbols; the second global symbol table does the same for 64-bit file members. If the archive has no 32-bit or 64-bit file members, the respective global symbol table is omitted. The strip command can be used to delete one or both global symbol tables from the archive. The fl_gstoff field in the fixed-length header contains the offset to the 32-bit global symbol table, and the fl_gst64off contains the offset to the 64-bit global symbol table.
Reviewers: James Henderson,Stephen Peckham
Differential Revision: https://reviews.llvm.org/D142479
If a symbol needs both JUMP_SLOT and GLOB_DAT relocations, there is a
minor linker optimization to keep just GLOB_DAT. This optimization
is only implemented by GNU ld's x86 port and mold.
https://maskray.me/blog/2021-08-29-all-about-global-offset-table#combining-.got-and-.got.plt
With the optimizing, the PLT entry is placed in .plt.got and the
associated GOTPLT entry is placed in .got (ld.bfd -z now) or .got.plt (ld.bfd -z lazy).
The relocation is in .rel[a].dyn.
This patch synthesizes `symbol@plt` labels for these .plt.got entries.
Example:
```
cat > a.s <<e
.globl _start; _start:
mov combined0@gotpcrel(%rip), %rax; mov combined1@gotpcrel(%rip), %rax
call combined0@plt; call combined1@plt
call foo0@plt; call foo1@plt
e
cat > b.s <<e
.globl foo0, foo1, combined0, combined1
foo0: foo1: combined0: combined1:
e
gcc -fuse-ld=bfd -shared b.s -o b.so
gcc -fuse-ld=bfd -pie -nostdlib a.s b.so -o a
```
```
Disassembly of section .plt:
0000000000001000 <.plt>:
1000: ff 35 ea 1f 00 00 pushq 0x1fea(%rip) # 0x2ff0 <_GLOBAL_OFFSET_TABLE_+0x8>
1006: ff 25 ec 1f 00 00 jmpq *0x1fec(%rip) # 0x2ff8 <_GLOBAL_OFFSET_TABLE_+0x10>
100c: 0f 1f 40 00 nopl (%rax)
0000000000001010 <foo1@plt>:
1010: ff 25 ea 1f 00 00 jmpq *0x1fea(%rip) # 0x3000 <_GLOBAL_OFFSET_TABLE_+0x18>
1016: 68 00 00 00 00 pushq $0x0
101b: e9 e0 ff ff ff jmp 0x1000 <.plt>
0000000000001020 <foo0@plt>:
1020: ff 25 e2 1f 00 00 jmpq *0x1fe2(%rip) # 0x3008 <_GLOBAL_OFFSET_TABLE_+0x20>
1026: 68 01 00 00 00 pushq $0x1
102b: e9 d0 ff ff ff jmp 0x1000 <.plt>
Disassembly of section .plt.got:
0000000000001030 <combined0@plt>:
1030: ff 25 a2 1f 00 00 jmpq *0x1fa2(%rip) # 0x2fd8 <foo1+0x2fd8>
1036: 66 90 nop
0000000000001038 <combined1@plt>:
1038: ff 25 a2 1f 00 00 jmpq *0x1fa2(%rip) # 0x2fe0 <foo1+0x2fe0>
103e: 66 90 nop
```
For x86-32, with -z now, if we remove `foo0` and `foo1`, the absence of regular
PLT will cause GNU ld to omit .got.plt, and our code cannot synthesize @plt
labels. This is an extreme corner case that almost never happens in practice (to
trigger the case, ensure every PLT symbol has been taken address). To fix it, we
can get the `_GLOBAL_OFFSET_TABLE_` symbol value, but the complexity is not
worth it.
Close https://github.com/llvm/llvm-project/issues/62537
Reviewed By: bd1976llvm
Differential Revision: https://reviews.llvm.org/D149817
Summary:
1. we use the unsigned type for NextOffset,PrevOffset ,GlobalSymbolOffset , MemberTableSize, it will caused a malform big archive when the archive file size is large than 4G.
2. also fix a NFC comment on https://reviews.llvm.org/D142479#inline-1443927
Reviewers: James Henderson
Differential Revision: https://reviews.llvm.org/D150462
This patch encapsulates the encoding and decoding logic of basic block metadata into the Metadata struct, and also reduces the decoded size of `SHT_LLVM_BB_ADDR_MAP` section.
The patch would've looked more readable if we could use designated initializer, but that is a c++20 feature.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D148360
The generic ABI says:
> Padding is present, if necessary, to ensure 8 or 4-byte alignment for the next note entry (depending on whether the file is a 64-bit or 32-bit object). Such padding is not included in descsz.
Our parsing code currently aligns n_namesz. Fix the bug by aligning the start
offset of the descriptor instead. This issue has been benign because the primary
uses of sh_addralign=8 notes are `.note.gnu.property`, where
`sizeof(Elf_Nhdr) + sizeof("GNU") = 16` (already aligned by 8).
In practice, many 64-bit systems incorrectly use sh_addralign=4 notes.
We can use sh_addralign (= p_align) to decide the descriptor padding.
Treat an alignment of 0 and 1 as 4. This approach matches modern GNU readelf
(since 2018).
We have a few tests incorrectly using sh_addralign=0. We may make our behavior
stricter after fixing these tests.
Linux kernel dumped core files use `p_align=0` notes, so we need to support the
case for compatibility.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D150022
GotPltSectionVA is specific to x86-32 PIC PLT entries.
Let's remove the argument from the generic interface.
As a side effect of not requiring .got.plt, this simplification
addresses a subset of https://github.com/llvm/llvm-project/issues/62537
by enabling .plt dumping for some ld.bfd -z now linked x86-32/x86-64 images
without .got.plt
This patch details the GOFF file format and implements the GOFFObjectfile class
with support for only the HDR, ESD and END GOFF records.
Reviewed By: jhenderson, kpn
Differential Revision: https://reviews.llvm.org/D98437
This patch details the GOFF file format and implements the GOFFObjectfile class
with support for only the HDR, ESD and END GOFF records.
Reviewed By: jhenderson, kpn
Differential Revision: https://reviews.llvm.org/D98437
On AIX, when the input files are LLVM bitcode files, `llvm-ar` should set the archive kind to `K_AIXBIG` as well, instead of leaving it to the default `K_GNU`.
Reviewed By: daltenty
Differential Revision: https://reviews.llvm.org/D149377
Fixes uninitialized memory access revealed by https://reviews.llvm.org/D146534.
In empty archives, we use Child(nullptr,nullptr,nullptr) in Archive constructor in setFirstRegular. This copies unitialized StartOfFile to FirstRegularStartOfFile, which child_begin may use later.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D148955
Similar to D125411, but for ARM64X.
ARM64X PE binaries are hybrids containing both ARM64EC and pure ARM64
variants in one file. They are usually linked by passing separate
ARM64EC and ARM64 object files to linker. Linked binaries use ARM64
machine and contain additional CHPE metadata in their load config.
CHPE metadata support is not part of this patch, I plan to send that later.
Using ARM64X as a machine type of object files themselves is somewhat
ambiguous, but such files are allowed by MSVC. It treats them as ARM64
or ARM64EC object, depending on the context. Such objects can be
produced with cvtres.exe -machine:arm64x.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D148517
This is useful for examining ARM64EC static libraries and allows
better llvm-lib testing. Changes to Archive class will also be
useful for LLD to support ARM64EC, where it will need to use one
map or the other, depending on linking target (or both, in case of
ARM64X, but separately as they are in different namespaces).
Reviewed By: jhenderson, efriedma
Differential Revision: https://reviews.llvm.org/D146534
ARM64EC allows having both pure ARM64 objects and ARM64EC in the
same archive. This allows using single static library for linking
pure ARM64, pure ARM64EC or mixed modules (what MS calls ARM64X:
a single module that may be used in both modes). To achieve that,
such static libraries need two separated symbol maps. The usual map
contains only pure ARM64 symbols, while a new /<ECSYMBOLS>/ section
contains EC symbols. EC symbols map has very similar format to the
usual map, except it doesn't contain object offsets and uses offsets
from regular map instead. This is true even for pure ARM64EC static
library: it will simply have 0 symbols in the symbol map.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D143541
A quirk of the AMDGPU backend is EF_AMDGPU_MACH_NONE, which is not
specific to the r600 or amdgcn architecture, but can be combined with
either.
AMDGPU ELF code objects with this mach value cannot be mapped back to a
Triple architecture, as it could be either r600 or amdgcn. For
llvm-dwarfdump this means the normal method of inspecting
ObjectFile::getArch to determine how to handle relocations is
insufficient.
This patch adds an extra check for ELF code objects which would
otherwise be categorized as UnknownArch, making it possible to use
llvm-dwarfdump with them. For completeness it also adds support for
known r600 machines.
This also adds specific tests for llvm-dwarfdump for amdgcn and r600,
both with known and unknown mach values.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D144301
This patch replaces the uses of PointerUnion.is function by llvm::isa,
PointerUnion.get function by llvm::cast, and PointerUnion.dyn_cast by
llvm::dyn_cast_if_present. This is according to the FIXME in
the definition of the class PointerUnion.
This patch does not remove them as they are being used in other
subprojects.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D148449
This makes parsing for build IDs in the markup filter slightly more
permissive, in line with fromHex.
It also removes the distinction between missing build ID and empty build
ID; empty build IDs aren't a useful concept, since their purpose is to
uniquely identify a binary. This removes a layer of indirection wherever
build IDs are obtained.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D147485
This Moves ELFObjectFile to using
RISCVISAInfo::parseNormalizedArchString which is not an NFC, as the test
changes show. D144353 transitioned LLD to using this function, which is
specialised to parsing arch strings in the normalised format specified
in the psABI rather than user-authored strings accepted in `-march`,
which has greater flexibility.
parseNormalizedArchString does not ignore or produce an error for ISA
extensions with a version that isn't recognised/supported by LLVM. As
current GCC is marking its objects with a higher version of the A, F,
and D extensions than LLVM (see [extension versioning
discussion](https://discourse.llvm.org/t/rfc-resolving-issues-related-to-extension-versioning-in-risc-v/68472)
this massively improves the usability of llvm-objdump with such
binaries.
Differential Revision: https://reviews.llvm.org/D146114
We currently just use GNU format for llvm-lib. This mostly works, but
ARM64EC needs an additional section that does not really fit GNU format.
This patch implements writing in COFF format (as in, it's what archive
reader considers as K_COFF). This mostly requires symbol emitting symbol
map. Note that, just like in case of MSVC, symbols are de-duplicated in
both usual symbol table and the new symbol map.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D143540
Having string table in members vector does not fit later patches in
this series. Symbol map needs to refer to objects' offsets, but string
table should not be referenced. Also for ARM64EC, the new <ECSYMBOLS>
table is inserted after string table.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D143538
Currently when using the LLVM tools (eg llvm-readobj, llvm-objdump) to
find information about basic block locations using the propeller tooling
in relocatable object files function addresses are not mapped properly
which causes problems. In llvm-readobj this means that incorrect
function names will be pulled. In llvm-objdum this means that most BBs
won't show up in the output if --symbolize-operands is used. This patch
changes the behavior of decodeBBAddrMap to trace through relocations
to get correct function addresses if it is going through a relocatable
object file. This fixes the behavior in both tools and also other
consumers of decodeBBAddrMap. Some helper functions have been added
in/refactoring done to aid in grabbing BB address map sections now that
in some cases both relocation and BB address map sections need to be
obtained at the same time.
Regression tests moved around/added.
Differential Revision: https://reviews.llvm.org/D143841
This refactoring will allow for this utility function to be used in
other places in the codebase outside of the llvm-readobj tool.
Reviewed By: jhenderson, rahmanl
Differential Revision: https://reviews.llvm.org/D144783
If the archive contains free list and contains no member file, the buffer length doesn't equal to length of the header.
Reviewed By: Esme, DiggerLin, #powerpc
Differential Revision: https://reviews.llvm.org/D138986
This includes handling of new attributes for symbols & rpath.
In the event that an older format file is compared to tbd_v5, ignore these new attributes.
Reviewed By: ributzka
Differential Revision: https://reviews.llvm.org/D144529
The forwarding header is left in place because of its use in
`polly/lib/External/isl/interface/extract_interface.cc`, but I have
added a GCC warning about the fact it is deprecated, because it is used
in `isl` from where it is included by Polly.
This patch continues implementing DirectX pipeline state validation
information by adding support for resource binding metadata.
Reviewed By: python3kgae
Differential Revision: https://reviews.llvm.org/D143130
DirectX shader pipeline state validation information is a fairly
complicated to serialize data structure. This patch adds the first bit
of support for reading and writing the runtime info structure which
comes first in the encoded data.
Subsequent patches will flesh out the remaining fields of the data
structure.
There is no official documentation for the format, but the format is
roughly documented in the code comment here:
https://github.com/microsoft/DirectXShaderCompiler/blob/main/include/dxc
/DxilContainer/DxilPipelineStateValidation.h#L731
Reviewed By: python3kgae
Differential Revision: https://reviews.llvm.org/D141649
This reverts commit 7f0003c19c3a47f484ea9cc929728808b27ace32.
Reason: This broke the ASan buildbot, see the comments in
https://reviews.llvm.org/D138986 for more information.
If the archive contains free list and contains no member file, the buffer length doesn't equal to length of the header.
Reviewed By: Esme, DiggerLin, #powerpc
Differential Revision: https://reviews.llvm.org/D138986
Let Propeller use specialized IDs for basic blocks, instead of MBB number.
This allows optimizations not just prior to asm-printer, but throughout the entire codegen.
This patch only implements the functionality under the new `LLVM_BB_ADDR_MAP` version, but the old version is still being used. A later patch will change the used version.
####Background
Today Propeller uses machine basic block (MBB) numbers, which already exist, to map native assembly to machine IR. This is done as follows.
- Basic block addresses are captured and dumped into the `LLVM_BB_ADDR_MAP` section just before the AsmPrinter pass which writes out object files. This ensures that we have a mapping that is close to assembly.
- Profiling mapping works by taking a virtual address of an instruction and looking up the `LLVM_BB_ADDR_MAP` section to find the MBB number it corresponds to.
- While this works well today, we need to do better when we scale Propeller to target other Machine IR optimizations like spill code optimization. Register allocation happens earlier in the Machine IR pipeline and we need an annotation mechanism that is valid at that point.
- The current scheme will not work in this scenario because the MBB number of a particular basic block is not fixed and changes over the course of codegen (via renumbering, adding, and removing the basic blocks).
- In other words, the volatile MBB numbers do not provide a one-to-one correspondence throughout the lifetime of Machine IR. Profile annotation using MBB numbers is restricted to a fixed point; only valid at the exact point where it was dumped.
- Further, the object file can only be dumped before AsmPrinter and cannot be dumped at an arbitrary point in the Machine IR pass pipeline. Hence, MBB numbers are not suitable and we need something else.
####Solution
We propose using fixed unique incremental MBB IDs for basic blocks instead of volatile MBB numbers. These IDs are assigned upon the creation of machine basic blocks. We modify `MachineFunction::CreateMachineBasicBlock` to assign the fixed ID to every newly created basic block. It assigns `MachineFunction::NextMBBID` to the MBB ID and then increments it, which ensures having unique IDs.
To ensure correct profile attribution, multiple equivalent compilations must generate the same Propeller IDs. This is guaranteed as long as the MachineFunction passes run in the same order. Since the `NextBBID` variable is scoped to `MachineFunction`, interleaving of codegen for different functions won't cause any inconsistencies.
The new encoding is generated under the new version number 2 and we keep backward-compatibility with older versions.
####Impact on Size of the `LLVM_BB_ADDR_MAP` Section
Emitting the Propeller ID results in a 23% increase in the size of the `LLVM_BB_ADDR_MAP` section for the clang binary.
Reviewed By: tmsriram
Differential Revision: https://reviews.llvm.org/D100808
Use deduction guides instead of helper functions.
The only non-automatic changes have been:
1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*))
2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase.
3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated.
4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that).
Per reviewers' comment, some useless makeArrayRef have been removed in the process.
This is a follow-up to https://reviews.llvm.org/D140896 that introduced
the deduction guides.
Differential Revision: https://reviews.llvm.org/D140955
