This is a resurrection of D106421 with the change that it keeps backward-compatibility. This means decoding the previous version of `LLVM_BB_ADDR_MAP` will work. This is required as the profile mapping tool is not released with LLVM (AutoFDO). As suggested by @jhenderson we rename the original section type value to `SHT_LLVM_BB_ADDR_MAP_V0` and assign a new value to the `SHT_LLVM_BB_ADDR_MAP` section type. The new encoding adds a version byte to each function entry to specify the encoding version for that function. This patch also adds a feature byte to be used with more flexibility in the future. An use-case example for the feature field is encoding multi-section functions more concisely using a different format.
Conceptually, the new encoding emits basic block offsets and sizes as label differences between each two consecutive basic block begin and end label. When decoding, offsets must be aggregated along with basic block sizes to calculate the final offsets of basic blocks relative to the function address.
This encoding uses smaller values compared to the existing one (offsets relative to function symbol).
Smaller values tend to occupy fewer bytes in ULEB128 encoding. As a result, we get about 17% total reduction in the size of the bb-address-map section (from about 11MB to 9MB for the clang PGO binary).
The extra two bytes (version and feature fields) incur a small 3% size overhead to the `LLVM_BB_ADDR_MAP` section size.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D121346
This is the first patch of a series to upstream support for the new
subtarget.
Contributors:
Jay Foad <jay.foad@amd.com>
Konstantin Zhuravlyov <kzhuravl_dev@outlook.com>
Patch 1/N for upstreaming AMDGPU gfx11 architectures.
Reviewed By: foad, kzhuravl, #amdgpu
Differential Revision: https://reviews.llvm.org/D124536
This ELF note is aarch64 and Android-specific. It specifies to the
dynamic loader that specific work should be scheduled to enable MTE
protection of stack and heap regions.
Current synthesis of the ".note.android.memtag" ELF note is done in the
Android build system. We'd like to move that to the compiler, and this
is the first step.
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D119381
Instead of the GNU extension `SHF_GNU_RETAIN`, Solaris provides equivalent
functionality with `SHF_SUNW_NODISCARD`. This patch implements the necessary
support.
Tested on `sparcv9-sun-solaris2.11`, `amd64-pc-solaris2.11`, and
`x86_64-pc-linux-gnu`.
Differential Revision: https://reviews.llvm.org/D107955
This patch adds necessary definitions for LoongArch ELF files, including
relocation types. Also adds initial support to ELFYaml, llvm-objdump,
and llvm-readobj in order to work with LoongArch ELFs.
Differential revision: https://reviews.llvm.org/D115859
Summary:
Add code object v5 support (deafult is still v4)
Generate metadata for implicit kernel args for the new ABI
Set the metadata version to be 1.2
Reviewers:
t-tye, b-sumner, arsenm, and bcahoon
Fixes:
SWDEV-307188, SWDEV-307189
Differential Revision:
https://reviews.llvm.org/D118272
Notes generated in OpenBSD core files provide additional information
about the kernel state and CPU registers. These notes are described
in core.5, which can be viewed here: https://man.openbsd.org/core.5
Differential Revision: https://reviews.llvm.org/D111966
The MSP430 ABI supports build attributes for specifying
the ISA, code model, data model and enum size in ELF object files.
Differential Revision: https://reviews.llvm.org/D107969
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 patch adds support for a new field in the FileHeader, which states
the name to use for the section header string table. This also allows
combining the string table with another string table in the object, e.g.
the symbol name string table. The field is optional. By default,
.shstrtab will continue to be used.
This partially fixes https://bugs.llvm.org/show_bug.cgi?id=50506.
Reviewed by: Higuoxing
Differential Revision: https://reviews.llvm.org/D104035
As suggested in https://bugs.llvm.org/show_bug.cgi?id=50527, this
moves the DenseMapInfo for APInt and APSInt into the respective
headers, removing the need to include APInt.h and APSInt.h from
DenseMapInfo.h.
We could probably do the same from StringRef and ArrayRef as well.
Differential Revision: https://reviews.llvm.org/D103422
The `e_flags` contains a mixture of bitfields and regular ones, ensure all of them can be serialized and deserialized.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D100250
- Add the M68k-specific MC layer implementation
- Add ELF support for M68k
- Add M68k-specifc CC and reloc
TODO: Currently AsmParser and disassembler are not implemented yet.
Please use this bug to track the status:
https://bugs.llvm.org/show_bug.cgi?id=48976
Authors: myhsu, m4yers, glaubitz
Differential Revision: https://reviews.llvm.org/D88390
As discussed in D95511, this allows us to encode invalid BBAddrMap
sections to be used in more rigorous testing.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D96831
As discussed in D95511, this allows us to encode invalid BBAddrMap
sections to be used in more rigorous testing.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D96831
The current support only printed coredump notes, but most binaries also
contain notes. This change adds names for four FreeBSD-specific notes and
pretty-prints three of them:
NT_FREEBSD_ABI_TAG:
This note holds a 32-bit (decimal) integer containing the value of the
__FreeBSD_version macro, which is defined in crt1.o and will hold a value
such as 1300076 for a binary build on a FreeBSD 13 system.
NT_FREEBSD_ARCH_TAG:
A string containing the value of the build-time MACHINE_ARCH
NT_FREEBSD_FEATURE_CTL: A 32-bit flag that indicates to the kernel that
the binary wants certain bevahiour. Examples include setting
NT_FREEBSD_FCTL_ASLR_DISABLE which tells the kernel to disable ASLR.
After this change llvm-readobj also no longer decodes coredump-only
FreeBSD notes in non-coredump files. I've also converted the
note-freebsd.s test to use yaml2obj instead of llvm-mc.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D74393
In binutils, the flag is defined for ELFOSABI_GNU and ELFOSABI_FREEBSD.
It can be used to mark a section as a GC root.
In practice, the flag has generic semantics and can be applied to many
EI_OSABI values, so we consider it generic.
Differential Revision: https://reviews.llvm.org/D95728
Currently we don't allow the following definition:
```
Sections:
- Type: SectionHeaderTable
- Name: .foo
Type: SHT_PROGBITS
```
We report an error: "SectionHeaderTable can't be empty. Use 'NoHeaders' key to drop the section header table".
It was implemented in this way earlier, when `SectionHeaderTable`
was a dedicated key outside of the `Sections` list. And we did not
allow to select where the table is written.
Currently it makes sense to allow it, because a user might
want to place the default section header table at an arbitrary position,
e.g. before other sections. In this case it is not convenient and error prone
to require specifying all sections:
```
Sections:
- Type: SectionHeaderTable
Sections:
- Name: .foo
- Name: .strtab
- Name: .shstrtab
- Name: .foo
Type: SHT_PROGBITS
```
This patch allows empty SectionHeaderTable definitions.
Differential revision: https://reviews.llvm.org/D95341
D95140 introduced `static constexpr StringRef TypeStr = "SectionHeaderTable";` member
of `SectionHeaderTable` with in-class initialized. BB reports the link error:
/usr/bin/ld: lib/libLLVMObjectYAML.a(ELFYAML.cpp.o): in function
`llvm::yaml::MappingTraits<std::unique_ptr<llvm::ELFYAML::Chunk, std::default_delete<llvm::ELFYAML::Chunk> > >::mapping(llvm::yaml::IO&, std::unique_ptr<llvm::ELFYAML::Chunk, std::default_delete<llvm::ELFYAML::Chunk> >&)':
ELFYAML.cpp:(.text._ZN4llvm4yaml13MappingTraitsISt10unique_ptrINS_7ELFYAML5ChunkESt14default_deleteIS4_EEE7mappingERNS0_2IOERS7_+0x58): undefined reference to `llvm::ELFYAML::SectionHeaderTable::TypeStr'
/usr/bin/ld: ELFYAML.cpp:(.text._ZN4llvm4yaml13MappingTraitsISt10unique_ptrINS_7ELFYAML5ChunkESt14default_deleteIS4_EEE7mappingERNS0_2IOERS7_+0x353):undefined reference to `llvm::ELFYAML::SectionHeaderTable::TypeStr'
/usr/bin/ld: ELFYAML.cpp:(.text._ZN4llvm4yaml13MappingTraitsISt10unique_ptrINS_7ELFYAML5ChunkESt14default_deleteIS4_EEE7mappingERNS0_2IOERS7_+0x6e5): undefined reference to `llvm::ELFYAML::SectionHeaderTable::TypeStr'
This patch adds a definition to cpp file, I guess it should fix the issue.
This was discussed in D93678 thread.
Currently we have one special chunk - Fill.
This patch re implements the "SectionHeaderTable" key to become a special chunk too.
With that we are able to place the section header table at any location,
just like we place sections.
Differential revision: https://reviews.llvm.org/D95140
This makes the following improvements.
For `SHT_GNU_versym`:
* yaml2obj: set `sh_link` to index of `.dynsym` section automatically.
For `SHT_GNU_verdef`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version definitions.
For `SHT_GNU_verneed`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version dependencies.
Also, simplifies few test cases.
Differential revision: https://reviews.llvm.org/D94956
When a field is optional we can use the `=<none>` syntax in macros.
This patch makes `Value`/`Size` fields of `Symbol` optional
and adds test cases for them.
Differential revision: https://reviews.llvm.org/D93010
This is similar to what we did earlier for fields of the Section class.
When a field is optional we can use the =<none> syntax in macros.
This was splitted from D92478.
Differential revision: https://reviews.llvm.org/D92565
Currently when we dump sections, we dump them in the order,
which is specified in the sections header table.
With that the order in the output might not match the order in the file.
This patch starts sorting them by by file offsets when dumping.
When the order in the section header table doesn't match the order
in the file, we should emit the "SectionHeaderTable" key. This patch does it.
Differential revision: https://reviews.llvm.org/D91249
Imagine we have a YAML declaration of few sections: `foo1`, `<unnamed 2>`, `foo3`, `foo4`.
To put them into segment we can do (1*):
```
Sections:
- Section: foo1
- Section: foo4
```
or we can use (2*):
```
Sections:
- Section: foo1
- Section: foo3
- Section: foo4
```
or (3*) :
```
Sections:
- Section: foo1
## "(index 2)" here is a name that we automatically created for a unnamed section.
- Section: (index 2)
- Section: foo3
- Section: foo4
```
It looks really confusing that we don't have to list all of sections.
At first I've tried to make this rule stricter and report an error when there is a gap
(i.e. when a section is included into segment, but not listed explicitly).
This did not work perfect, because such approach conflicts with unnamed sections/fills (see (3*)).
This patch drops "Sections" key and introduces 2 keys instead: `FirstSec` and `LastSec`.
Both are optional.
Differential revision: https://reviews.llvm.org/D90458
Rahman Lavaee