[test] Use host platform specific error message substitution in lit tests

On z/OS, the following error message is not matched correctly in lit tests.

```
EDC5129I No such file or directory.
```

Th

[test] Use host platform specific error message substitution in lit tests

On z/OS, the following error message is not matched correctly in lit tests.

```
EDC5129I No such file or directory.
```

This patch uses a lit config substitution to check for platform specific error messages.

Reviewed By: muiez, jhenderson

Differential Revision: https://reviews.llvm.org/D95246

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Revert "[SystemZ][z/OS] Fix No such file or directory expression error"

This reverts commit 06f8a49693957bc27b83e0ab5f429ff874941a07.

[SystemZ][z/OS] Fix No such file or directory expression error matching in lit tests

On z/OS, the following error message is not matched correctly in lit tests. This patch updates the CHECK expressi

[SystemZ][z/OS] Fix No such file or directory expression error matching in lit tests

On z/OS, the following error message is not matched correctly in lit tests. This patch updates the CHECK expression to match successfully.
```
EDC5129I No such file or directory.
```

Reviewed By: muiez

Differential Revision: https://reviews.llvm.org/D94239

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[ELF][test] Split basic.s

[ThinLTO] Allow usage of all hardware threads in the system

Before this patch, it wasn't possible to extend the ThinLTO threads to all SMT/CMT threads in the system. Only one thread per core was all

[ThinLTO] Allow usage of all hardware threads in the system

Before this patch, it wasn't possible to extend the ThinLTO threads to all SMT/CMT threads in the system. Only one thread per core was allowed, instructed by usage of llvm::heavyweight_hardware_concurrency() in the ThinLTO code. Any number passed to the LLD flag /opt:lldltojobs=..., or any other ThinLTO-specific flag, was previously interpreted in the context of llvm::heavyweight_hardware_concurrency(), which means SMT disabled.

One can now say in LLD:
/opt:lldltojobs=0 -- Use one std::thread / hardware core in the system (no SMT). Default value if flag not specified.
/opt:lldltojobs=N -- Limit usage to N threads, regardless of usage of heavyweight_hardware_concurrency().
/opt:lldltojobs=all -- Use all hardware threads in the system. Equivalent to /opt:lldltojobs=$(nproc) on Linux and /opt:lldltojobs=%NUMBER_OF_PROCESSORS% on Windows. When an affinity mask is set for the process, threads will be created only for the cores selected by the mask.

When N > number-of-hardware-threads-in-the-system, the threads in the thread pool will be dispatched equally on all CPU sockets (tested only on Windows).
When N <= number-of-hardware-threads-on-a-CPU-socket, the threads will remain on the CPU socket where the process started (only on Windows).

Differential Revision: https://reviews.llvm.org/D75153

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[llvm-readelf] Make --all output order closer to GNU readelf

https://bugs.llvm.org/show_bug.cgi?id=43403

The new order makes it easy to compare the two tools' --all.

Reviewed By: grimar, rupprecht

[llvm-readelf] Make --all output order closer to GNU readelf

https://bugs.llvm.org/show_bug.cgi?id=43403

The new order makes it easy to compare the two tools' --all.

Reviewed By: grimar, rupprecht

Differential Revision: https://reviews.llvm.org/D75592

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[ELF][test] Change -o %t to -o /dev/null if the output is not needed

[ELF][X86] Allow PT_LOAD to have overlapping p_offset ranges on EM_X86_64

Port the D64906 technique to EM_X86_64.

Differential Revision: https://reviews.llvm.org/D67482

llvm-svn: 371958

[ELF] Add -z separate-code and pad the last page of last PF_X PT_LOAD with traps only if -z separate-code is specified

This patch

1) adds -z separate-code and -z noseparate-code (default).
2) chang

[ELF] Add -z separate-code and pad the last page of last PF_X PT_LOAD with traps only if -z separate-code is specified

This patch

1) adds -z separate-code and -z noseparate-code (default).
2) changes the condition that the last page of last PF_X PT_LOAD is
padded with trap instructions.
Current condition (after D33630): if there is no `SECTIONS` commands.
After this change: if -z separate-code is specified.

-z separate-code was introduced to ld.bfd in 2018, to place the text
segment in its own pages. There is no overlap in pages between an
executable segment and a non-executable segment:

1) RX cannot load initial contents from R or RW(or non-SHF_ALLOC).
2) R and RW(or non-SHF_ALLOC) cannot load initial contents from RX.

lld's current status:

- Between R and RX: in `Writer<ELFT>::fixSectionAlignments()`, the start of a
segment is always aligned to maxPageSize, so the initial contents loaded by R
and RX do not overlap. I plan to allow overlaps in D64906 if -z noseparate-code
is in effect.
- Between RX and RW(or non-SHF_ALLOC if RW doesn't exist):
we currently unconditionally pad the last page to commonPageSize
(defaults to 4096 on all targets we support).
This patch will make it effective only if -z separate-code is specified.

-z separate-code is a dubious feature that intends to reduce the number
of ROP gadgets (which is actually ineffective because attackers can find
plenty of gadgets in the text segment, no need to find gadgets in
non-code regions).

With the overlapping PT_LOAD technique D64906, -z noseparate-code
removes two more alignments at segment boundaries than -z separate-code.
This saves at most defaultCommonPageSize*2 bytes, which are significant
on targets with large defaultCommonPageSize (AArch64/MIPS/PPC: 65536).

Issues/feedback on alignment at segment boundaries to help understand
the implication:

* binutils PR24490 (the situation on ld.bfd is worse because they have
two R-- on both sides of R-E so more alignments.)

* In binutils, the 2018-02-27 commit "ld: Add --enable-separate-code" made -z separate-code the default on Linux.
https://github.com/richfelker/musl-cross-make/commit/d969dea983a2cc54a1e0308a0cdeb6c3307e4bfa
In musl-cross-make, binutils is configured with --disable-separate-code
to address size regressions caused by -z separate-code. (lld actually has the same
issue, which I plan to fix in a future patch. The ld.bfd x86 status is
worse because they default to max-page-size=0x200000).

* https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237676 people want
smaller code size. This patch will remove one alignment boundary.

* Stef O'Rear: I'm opposed to any kind of page alignment at the
text/rodata line (having a partial page of text aliased as rodata and
vice versa has no demonstrable harm, and I actually care about small
systems).

So, make -z noseparate-code the default.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D64903

llvm-svn: 367537

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[LLD][ELF] Add the -z ifunc-noplt option

Patch by Mark Johnston!

Summary:
When the option is configured, ifunc calls do not go through the PLT;
rather, they appear as regular function calls with re

[LLD][ELF] Add the -z ifunc-noplt option

Patch by Mark Johnston!

Summary:
When the option is configured, ifunc calls do not go through the PLT;
rather, they appear as regular function calls with relocations
referencing the ifunc symbol, and the resolver is invoked when
applying the relocation. This is intended for use in freestanding
environments where text relocations are permissible and is incompatible
with the -z text option. The option is motivated by ifunc usage in the
FreeBSD kernel, where ifuncs are used to elide CPU feature flag bit
checks in hot paths. Instead of replacing the cost of a branch with that
of an indirect function call, the -z ifunc-noplt option is used to ensure
that ifunc calls carry no hidden overhead relative to normal function
calls.

Test Plan:
I added a couple of regression tests and tested the FreeBSD kernel
build using the latest lld sources.

To demonstrate the effects of the change, I used a micro-benchmark
which results in frequent invocations of a FreeBSD kernel ifunc. The
benchmark was run with and without IBRS enabled, and with and without
-zifunc-noplt configured. The observed speedup is small and consistent,
and is significantly larger with IBRS enabled:

https://people.freebsd.org/~markj/ifunc-noplt/noibrs.txt
https://people.freebsd.org/~markj/ifunc-noplt/ibrs.txt

Reviewed By: ruiu, MaskRay

Differential Revision: https://reviews.llvm.org/D61613

llvm-svn: 360685

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Add typo correction for command-line flags to ELF and COFF lld drivers

For lld-link, unknown '/'-style flags are treated as filenames on POSIX
systems, so only '-'-style flags get typo correction fo

Add typo correction for command-line flags to ELF and COFF lld drivers

For lld-link, unknown '/'-style flags are treated as filenames on POSIX
systems, so only '-'-style flags get typo correction for now. This
matches clang-cl.

PR37006.

Differential Revision: https://reviews.llvm.org/D61443

llvm-svn: 360145

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[test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC

Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t

[test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC

Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651

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Propagate sh_entsize out.

No difference in practice other than having sh_entsize in the output.

This should simplify the patch for handling SHF_MERGE in -r.

Based on a patch by George Rimar.

llvm

Propagate sh_entsize out.

No difference in practice other than having sh_entsize in the output.

This should simplify the patch for handling SHF_MERGE in -r.

Based on a patch by George Rimar.

llvm-svn: 318306

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[ELF] Set p_memsz to p_filesz when aligning the last segment to page boundary

Having p_filesz different from p_memsz is confusing some tools.

Differential Revision: https://reviews.llvm.org/D37369

[ELF] Set p_memsz to p_filesz when aligning the last segment to page boundary

Having p_filesz different from p_memsz is confusing some tools.

Differential Revision: https://reviews.llvm.org/D37369

llvm-svn: 312384

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[ELF] - LTO: Try to be option compatible with the gold plugin.

This is relative to PR30720.

Previously we ignored all --plugin-opt arguments.
Patch adds support for them.

Patch does not add any ne

[ELF] - LTO: Try to be option compatible with the gold plugin.

This is relative to PR30720.

Previously we ignored all --plugin-opt arguments.
Patch adds support for them.

Patch does not add any new LTO options,
and just implements mapping from --plugin-opt to existent ones.

Differential revision: https://reviews.llvm.org/D36227

llvm-svn: 310826

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[ELF] When the code segment is the last, align it to the page boundary

When the data segment is the last segment, it is correct to leave
it unaligned. However, when the code segment is the last segm

[ELF] When the code segment is the last, align it to the page boundary

When the data segment is the last segment, it is correct to leave
it unaligned. However, when the code segment is the last segment,
it should be aligned to the page boundary to avoid loading the
non-segment parts of the ELF file at the end of the file.

Differential Revision: https://reviews.llvm.org/D33630

llvm-svn: 309829

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Change the error message format for duplicate symbols.

This patch is intended to improve readability of "duplicate symbol"
error messages.

Without this patch:

/ssd/clang/bin/ld.lld: error: /ssd/

Change the error message format for duplicate symbols.

This patch is intended to improve readability of "duplicate symbol"
error messages.

Without this patch:

/ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Relocations.cpp:1054: duplicate symbol 'lld::elf::demangle(llvm::StringRef)'
/ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Strings.cpp:93: previous definition was here

With this patch:

/ssd/clang/bin/ld.lld: error: duplicate symbol: lld::elf::demangle(llvm::StringRef)
>>> defined at Strings.cpp:93 (/ssd/llvm-project/lld/ELF/Strings.cpp:93)
>>> Strings.cpp.o:(lld::elf::demangle(llvm::StringRef)) in archive lib/liblldELF.a
>>> defined at Relocations.cpp:1054 (/ssd/llvm-project/lld/ELF/Relocations.cpp:1054)
>>> Relocations.cpp.o:(.text+0x4C30) in archive lib/liblldELF.a

Discussion thread:
http://lists.llvm.org/pipermail/llvm-dev/2017-March/111459.html

Differential Revision: https://reviews.llvm.org/D31507

llvm-svn: 299280

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Stop propagating Entsize.

Now that we combine multiple synthetic merge section into one output
section there is no point in trying to propagate a value.

llvm-svn: 294048

Support non-regular output files.

This patch enables something like "-o /dev/null".
Previouly, it failed because such files cannot be renamed.

Differential Revision: https://reviews.llvm.org/D28010

Support non-regular output files.

This patch enables something like "-o /dev/null".
Previouly, it failed because such files cannot be renamed.

Differential Revision: https://reviews.llvm.org/D28010

llvm-svn: 291496

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lld: Default image base address to 0x200000 on x86-64

Align to the large page size (known as a superpage or huge page).
FreeBSD automatically promotes large, superpage-aligned allocations.

Differen

lld: Default image base address to 0x200000 on x86-64

Align to the large page size (known as a superpage or huge page).
FreeBSD automatically promotes large, superpage-aligned allocations.

Differential Revision: https://reviews.llvm.org/D27042

llvm-svn: 287782

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Change the way how we print out line numbers.

LLD's error messages contain line numbers, function names or section names.
Currently they are formatter as follows.

foo.c (32): symbol 'foo' not fou

Change the way how we print out line numbers.

LLD's error messages contain line numbers, function names or section names.
Currently they are formatter as follows.

foo.c (32): symbol 'foo' not found
foo.c (function bar): symbol 'foo' not found
foo.c (.text+0x1234): symbol 'foo' not found

This patch changes them so that they are consistent with Clang's output.

foo.c:32: symbol 'foo' not found
foo.c:(function bar): symbol 'foo' not found
foo.c:(.text+0x1234): symbol 'foo' not found

Differential Revision: https://reviews.llvm.org/D26901

llvm-svn: 287537

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Simplify "missing argument" error message.

We do not have an option taking more than one arguments,
so we can just say "missing argument" instead of "missing argument(s)".

llvm-svn: 287454

Include version string into ".comment" section.

Summary:
This patch adds a ".comment" section to an output. The comment
section contains the linker's version string. You can now
find out whether a b

Include version string into ".comment" section.

Summary:
This patch adds a ".comment" section to an output. The comment
section contains the linker's version string. You can now
find out whether a binary is created by LLD or not using objdump
command like this.

$ objdump -s -j .comment foo

foo: file format elf64-x86-64

Contents of section .comment:
0000 00474343 3a202855 62756e74 7520342e .GCC: (Ubuntu 4.
0010 382e342d 32756275 6e747531 7e31342e 8.4-2ubuntu1~14.
...
00c0 766d2f74 72756e6b 20323835 38343629 vm/trunk 285846)
00d0 004c696e 6b65723a 204c4c44 20342e30 .Linker: LLD 4.0
00e0 2e302028 7472756e 6b203238 36343036 .0 (trunk 286406
00f0 2900 ).

Compilers emits .comment section as well, so the output contains
both compiler and linker information.

Alternative considered:

I first tried to add a SHT_NOTE section because GNU gold does that.
A NOTE section starts with a header which contains content type.
It turned out that ld.gold sets type NT_GNU_GOLD_VERSION to their
NOTE section. So the NOTE type is only for GNU gold (surprise!)

Next, I tried to create ".linker-version" section. However, it seems
that reusing the existing ".comment" section is better because 1)
other tools already know about .comment section and is able to strip
it and 2) the result contans not only linker info but also compiler
info.

Differential Revision: https://reviews.llvm.org/D26487

llvm-svn: 286496

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[ELF] Better error reporting for duplicate symbol

Differential revision: https://reviews.llvm.org/D26397

llvm-svn: 286244

Remove string table offsets from tests.

<N> where "foo (<N>)" is the offset of string "foo" in the string table.

llvm-svn: 285751