LLVM ObjectFile currently records the start offsets of sections as the
start of the section header, whereas most other tools (WABT, emscripten,
wasm-tools) record it as the start of the section content, after the
header. This affects binutils tools such as objdump and nm, but not
compilation/assembly (since that is driven by symbols and assembler
labels which already have their values inside the section payload rather
in the header. This patch updates LLVM to match the other tools.
Summary:
Currently, we don't emit any of the AMDGPU specific flags and options
when printing in GNU-mode (the default). This patch adds extra code to
handle outputting these values to match the output from GNU's `readelf`
when used on an AMDGPU image.
psABI v2.20 added R_LARCH_CALL36 and removed R_LARCH_DELETE / R_LARCH_CFA.
R_LARCH_CALL36 was designed for function call on medium code model where
the 2 instructions (pcaddu18i + jirl) must be adjacent.
The `S_INLINEES` debug symbol is used to record all the functions that
are directly inlined within the current function (nested inlining is
ignored).
This change implements support for emitting the `S_INLINEES` debug
symbol in LLVM, and cleans up how the `S_INLINEES` and `S_CALLEES` debug
symbols are dumped.
GNU readelf introduced --extra-sym-info/-X to display the section name
for --syms (https://sourceware.org/PR30684). Port the feature, which is
currently llvm-readelf only.
For STO_AARCH64_VARIANT_PCS/STO_RISCV_VARIANT_PCS, the Ndx and Name
columns may not be aligned.
For a relocation, we don't differentiate the two cases:
* the symbol index is 0
* the symbol index is non zero, the type is not STT_SECTION, and the name is empty. Clang generates such local symbols for RISC-V linker relaxation.
So we may print
```
Offset Info Type Symbol's Value Symbol's Name + Addend
000000000000001c 0000000100000039 R_RISCV_32_PCREL 0000000000000000 0
// llvm-readobj
0x1C R_RISCV_32_PCREL - 0x0
```
while GNU readelf prints "<null>", which is clearer. Let's match the GNU behavior.
Related to https://reviews.llvm.org/D81842
```
000000000000001c 0000000100000039 R_RISCV_32_PCREL 0000000000000000 <null> + 0
// llvm-readobj
0x1C R_RISCV_32_PCREL <null> 0x0
```
Reviewed By: jhenderson, kito-cheng
Differential Revision: https://reviews.llvm.org/D155353
CHPE metadata is used by ARM64EC/ARM64X PE files to provide metadata for
emulator/loader. Most of this metadata will need to be generated by LLD.
Differential Revision: https://reviews.llvm.org/D149089
The LoongArch ELF psABI document has changed location and versioning
scheme; this revision is v2.10 in the old scheme. Notably this revision
brings initial capability of linker relaxation to LoongArch.
Reviewed By: SixWeining, MaskRay
Differential Revision: https://reviews.llvm.org/D152184
This information helps to avoid considering cloning for blocks with indirect branches.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D150611
This is a follow-up to b71edfaa4ec3c998aadb35255ce2f60bba2940b0
since I forgot the lit.local.cfg files in that one.
Reformatting is done with `black`.
If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.
If you run into any problems, post to discourse about it and
we will try to help.
RFC Thread below:
https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Reviewed By: barannikov88, kwk
Differential Revision: https://reviews.llvm.org/D150762
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
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
These are used to store new state added by the Scalable Matrix
Extension which is documented in
https://developer.arm.com/documentation/ddi0616/aa/.
The values match those defined by Linux, see:
e62252bc55/include/uapi/linux/elf.h (L435)
The ZT register(s) are added by SME2 which is not yet publicly
documented but has support in LLVM and Linux already.
Also added descriptions for SVE and PAC_MASK notes since those
were missing.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D148126
New versions I2.1, F2.2, D2.2 A2.1
Make F and Zfinx imply Zicsr.
Make G imply Zifencei.
This should have no impact to generated code. We have no plans to require Zicsr/Zifencei extension to be explicitly enabled to use Zicsr/Zifencei instructions in assembly.
See https://reviews.llvm.org/D147183 for documentation regarding what version specification we implement.
Reviewed By: asb
Differential Revision: https://reviews.llvm.org/D147179
Previously, the GNUELFDumper was the only implementer for Hash Histograms.
This patch moves the implementation for printHashHistogram and
printGnuHashHistogram into the ELFDumper base class, and allows each
derived class to specialize how it outputs that information.
This change also prevents the JSONELFDumper from emitting invalid JSON,
since the shared implementation in LLVMELFDumper no longer emits a
warning message to the output stream.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137096
The current implementation output the LLVM formatted heading for group
sections, which was not valid JSON. This patch provides two small
customization points that allow the heading to vary between the two
implementations, and another that allows the section members to be
output as valid JSON objects.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137095
Prior to this patch, the JSON output would emit an invalid key from the
shared LLVM implementation. This caused llvm-readobj to output invalid
JSON. This patch introduces a small helper function to print the
relocation information differently between the LLVM and JSON formats.
Before this patch:
```
"Relocations": [Section (2) .rel.text {
{
"Relocation": {
"Offset": 0,
"Type": {
"Value": "R_X86_64_NONE",
"RawValue": 0
},
"Symbol": {
"Value": "rel_0",
"RawValue": 1
}
}
},
...
```
After this patch:
```
"Relocations": [
{
"SectionIdx": 2,
"Relocs": [
{
"Relocation": {
"Offset": 0,
"Type": {
"Name": "R_X86_64_NONE",
"Value": 0
},
"Symbol": {
"Name": "rel_0",
"Value": 1
}
}
},
...
```
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137094
Today the JSON uses `Value` and `RawValue` when printing `Flags`, when really
the `Value` field is always the name of an Enum variant, and `RawValue` is its
underlying numeric value. Similarly, we rename the `RawFlags` key to `Value`,
to match the new scheme. This also allows JSON parsing to use consistent logic
for `Flag` types.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137091
The existing JSON incorrectly outputs line breaks and other invalid JSON.
Example Before this patch:
```
...
"Relocations":[Section (9) .rela.dyn {
0xA3B0 R_X86_64_RELATIVE - 0x43D0
0xA3B8 R_X86_64_RELATIVE - 0x4A30
...
```
Example After this patch:
```
...
"Relocations":[Section (9) .rela.dyn {
{"Relocation":{"Offset":41904,"Type":{"Value":"R_X86_64_RELATIVE","RawValue":8},
"Symbol":{"Value":"","RawValue":0},"Addend":17360}},
{"Relocation":{"Offset":41912,"Type":{"Value":"R_X86_64_RELATIVE","RawValue":8},
"Symbol":{"Value":"","RawValue":0},"Addend":18992}},
{"Relocation":{"Offset":41920,"Type":{"Value":"R_X86_64_RELATIVE","RawValue":8},
"Symbol":{"Value":"","RawValue":0},"Addend":17440}},
...
```
Note there are still issues with the Section, but each Relocation is
now a valid JSON object that can be parsed. Future patches will address
the issues regarding JSON output for the Section.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137089
Today, the LLVM output uses special handling when the Other field is 0.
This output makes sense for a command line utility that a human will
read, but JSON is a machine readable format, so being consistent is more
important. Prior to this change, any consumer of the JSON output would
need to handle the Other field specially, since the structure of the
JSON would no longer be consistent.
Changes to JSON output when Other flag == 0:
```
"Other": 0, -> "Other": {
"RawFlags": 0,
"Flags": []
},
```
There are no changes to when Other flag != 0:
```
"Other": { -> "Other": {
"RawFlags": 1, "RawFlags": 1,
"Flags": [ "Flags": [
... ...
] ]
}, },
```
This patch adds a overload for the JSONELFDumper's printSymbol() method,
that uses consistent output formatting, regardless of the value of the
Other field.
Depends on D137092
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D137088
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
Summary:
The llvm-readobj prints extra characters for the timestamp when --file-headers is used with an XCOFF file. This change updates the format string used to print the time. In addition, the timestamp is printed in the local timezone, and a thread-safe call is used to convert the time.
Summit the patch on behalf of Stephen Peckham.
Reviewers: James Henderson, Digger Lin
Differential Revision: https://reviews.llvm.org/D144281
This adds functionality to readelf/readobj to specifically handle
MTE-related bits, like the AARCH64_MEMTAG_* dynamic entries, and a
decoder for the Android-specific ELF note.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D143693
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
Add file with Xtensa ELF relocations. Add Xtensa support to ELF.h,
ELFObject.h and ELFYAML.cpp. Add simple test of Xtensa ELF representation in YAML.
Differential Revision: https://reviews.llvm.org/D64827
