[ELF] Support 'G' in .eh_frame

Reviewed By: MaskRay, eugenis

Differential Revision: https://reviews.llvm.org/D127148

Revert "[ELF] Support 'G' in .eh_frame"

This reverts commit 40f34fe4a87d5171854b9b65678ef3d9baea5785.

[ELF] Support 'G' in .eh_frame

Reviewed By: MaskRay, eugenis

Differential Revision: https://reviews.llvm.org/D127148

[ELF] Replace uncompressed InputSectionBase::data() with rawData. NFC

In many call sites we know uncompression cannot happen (non-SHF_ALLOC, or the
data (even if compressed) must have been uncompres

[ELF] Replace uncompressed InputSectionBase::data() with rawData. NFC

In many call sites we know uncompression cannot happen (non-SHF_ALLOC, or the
data (even if compressed) must have been uncompressed by a previous pass).
Prefer rawData in these cases. data() increases code size and prevents
optimization on rawData.

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[ELF] Simplify/optimize EhInputSection::split

and change some `fatal` to `errorOrWarn`.

EhFrame.cpp is a helper file. We don't place all .eh_frame implementation there,
so the code move is fine.

ELF: Teach the linker about the 'B' augmentation string character.

This character indicates that when return pointer authentication is
being used, the function signs the return address using the B k

ELF: Teach the linker about the 'B' augmentation string character.

This character indicates that when return pointer authentication is
being used, the function signs the return address using the B key.

Differential Revision: https://reviews.llvm.org/D93954

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[ELF] Support .cfi_signal_frame

glibc/sysdeps/unix/sysv/linux/x86_64/sigaction.c libc.a(sigaction.o) has a CIE
with the augmentation string "zRS". Support 'S' to allow --icf={safe,all}.

[ELF] --icf: don't fold text sections with LSDA

Fix PR36272 and PR46835

A .eh_frame FDE references a text section and (optionally) a LSDA (in
.gcc_except_table). Even if two text sections have ide

[ELF] --icf: don't fold text sections with LSDA

Fix PR36272 and PR46835

A .eh_frame FDE references a text section and (optionally) a LSDA (in
.gcc_except_table). Even if two text sections have identical content and
relocations (e.g. a() and b()), we cannot fold them if their LSDA are different.

```
void foo();
void a() {
try { foo(); } catch (int) { }
}
void b() {
try { foo(); } catch (float) { }
}
```

Scan .eh_frame pieces with LSDA and disallow referenced text sections to be
folded. If two .gcc_except_table have identical semantics (usually identical
content with PC-relative encoding), we will lose folding opportunity.
For ClickHouse (an exception-heavy application), this can reduce --icf=all efficiency
from 9% to 5%. There may be some percentage we can reclaim without affecting
correctness, if we analyze .eh_frame and .gcc_except_table sections.

gold 2.24 implemented a more complex fix (resolution to
https://sourceware.org/bugzilla/show_bug.cgi?id=21066) which combines the
checksum of .eh_frame CIE/FDE pieces.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D84610

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[ELF] Use namespace qualifiers (lld:: or elf::) instead of `namespace lld { namespace elf {`

Similar to D74882. This reverts much code from commit
bd8cfe65f5fee4ad573adc2172359c9552e8cdc0 (D68323) a

[ELF] Use namespace qualifiers (lld:: or elf::) instead of `namespace lld { namespace elf {`

Similar to D74882. This reverts much code from commit
bd8cfe65f5fee4ad573adc2172359c9552e8cdc0 (D68323) and fixes some
problems before D68323.

Sorry for the churn but D68323 was a mistake. Namespace qualifiers avoid
bugs where the definition does not match the declaration from the
header. See
https://llvm.org/docs/CodingStandards.html#use-namespace-qualifiers-to-implement-previously-declared-functions (D74515)

Differential Revision: https://reviews.llvm.org/D79982

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[ELF] Wrap things in `namespace lld { namespace elf {`, NFC

This makes it clear `ELF/**/*.cpp` files define things in the `lld::elf`
namespace and simplifies `elf::foo` to `foo`.

Reviewed By: atana

[ELF] Wrap things in `namespace lld { namespace elf {`, NFC

This makes it clear `ELF/**/*.cpp` files define things in the `lld::elf`
namespace and simplifies `elf::foo` to `foo`.

Reviewed By: atanasyan, grimar, ruiu

Differential Revision: https://reviews.llvm.org/D68323

llvm-svn: 373885

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[Coding style change] Rename variables so that they start with a lowercase letter

This patch is mechanically generated by clang-llvm-rename tool that I wrote
using Clang Refactoring Engine just for

[Coding style change] Rename variables so that they start with a lowercase letter

This patch is mechanically generated by clang-llvm-rename tool that I wrote
using Clang Refactoring Engine just for creating this patch. You can see the
source code of the tool at https://reviews.llvm.org/D64123. There's no manual
post-processing; you can generate the same patch by re-running the tool against
lld's code base.

Here is the main discussion thread to change the LLVM coding style:
https://lists.llvm.org/pipermail/llvm-dev/2019-February/130083.html
In the discussion thread, I proposed we use lld as a testbed for variable
naming scheme change, and this patch does that.

I chose to rename variables so that they are in camelCase, just because that
is a minimal change to make variables to start with a lowercase letter.

Note to downstream patch maintainers: if you are maintaining a downstream lld
repo, just rebasing ahead of this commit would cause massive merge conflicts
because this patch essentially changes every line in the lld subdirectory. But
there's a remedy.

clang-llvm-rename tool is a batch tool, so you can rename variables in your
downstream repo with the tool. Given that, here is how to rebase your repo to
a commit after the mass renaming:

1. rebase to the commit just before the mass variable renaming,
2. apply the tool to your downstream repo to mass-rename variables locally, and
3. rebase again to the head.

Most changes made by the tool should be identical for a downstream repo and
for the head, so at the step 3, almost all changes should be merged and
disappear. I'd expect that there would be some lines that you need to merge by
hand, but that shouldn't be too many.

Differential Revision: https://reviews.llvm.org/D64121

llvm-svn: 365595

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[ELF][MachO][wasm] Simplify range-style std::find{,_if} with STLExtras.h utilities. NFC

llvm-svn: 357269

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Avoid unnecessary buffer allocation and memcpy for compressed sections.

Previously, we uncompress all compressed sections before doing anything.
That works, and that is conceptually simple, but that

Avoid unnecessary buffer allocation and memcpy for compressed sections.

Previously, we uncompress all compressed sections before doing anything.
That works, and that is conceptually simple, but that could results in
a waste of CPU time and memory if uncompressed sections are then
discarded or just copied to the output buffer.

In particular, if .debug_gnu_pub{names,types} are compressed and if no
-gdb-index option is given, we wasted CPU and memory because we
uncompress them into newly allocated bufers and then memcpy the buffers
to the output buffer. That temporary buffer was redundant.

This patch changes how to uncompress sections. Now, compressed sections
are uncompressed lazily. To do that, `Data` member of `InputSectionBase`
is now hidden from outside, and `data()` accessor automatically expands
an compressed buffer if necessary.

If no one calls `data()`, then `writeTo()` directly uncompresses
compressed data into the output buffer. That eliminates the redundant
memory allocation and redundant memcpy.

This patch significantly reduces memory consumption (20 GiB max RSS to
15 Gib) for an executable whose .debug_gnu_pub{names,types} are in total
5 GiB in an uncompressed form.

Differential Revision: https://reviews.llvm.org/D52917

llvm-svn: 343979

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[ELF] Simplify read32. NFC

llvm-svn: 328908

Merge {COFF,ELF}/Strings.cpp to Common/Strings.cpp.

This should resolve the issue that lld build fails in some hosts
that uses case-insensitive file system.

Differential Revision: https://reviews.l

Merge {COFF,ELF}/Strings.cpp to Common/Strings.cpp.

This should resolve the issue that lld build fails in some hosts
that uses case-insensitive file system.

Differential Revision: https://reviews.llvm.org/D43788

llvm-svn: 326339

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Consistent (non) use of empty lines in include blocks

The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.

Differential Rev

Consistent (non) use of empty lines in include blocks

The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.

Differential Revision: https://reviews.llvm.org/D43528

llvm-svn: 325629

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De-template EhReader. NFC.

llvm-svn: 316733

De-template elf::getObjMsg. NFC.

llvm-svn: 316732

[lld] unified COFF and ELF error handling on new Common/ErrorHandler

Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error han

[lld] unified COFF and ELF error handling on new Common/ErrorHandler

Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39259

llvm-svn: 316624

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Revert rL313697, "Compact EhSectionPiece from 32 bytes to 16 bytes."

It broke selfhosting.
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/4896

llvm-svn: 313731

Compact EhSectionPiece from 32 bytes to 16 bytes.

EhSectionPiece used to have a pointer to a section, but that pointer was
mostly redundant because we almost always know what the section is without

Compact EhSectionPiece from 32 bytes to 16 bytes.

EhSectionPiece used to have a pointer to a section, but that pointer was
mostly redundant because we almost always know what the section is without
using that pointer. This patch removes the pointer from the struct.

This patch also use uint32_t/int32_t instead of size_t to represent
offsets that are hardly be larger than 4 GiB. At the moment, I think it is
OK even if we cannot handle .eh_frame sections larger than 4 GiB.

Differential Revision: https://reviews.llvm.org/D38012

llvm-svn: 313697

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Rename EhSectionPiece::ID -> EhSectionPiece::Sec.

ID sounds like an identifier, but this is actually a pointer to a section.

llvm-svn: 313588

Move Object format code to lib/BinaryFormat.

This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various type

Move Object format code to lib/BinaryFormat.

This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864

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Change the error format to report corrupted .eh_frame.

llvm-svn: 299289