svn commit: r351987 - in vendor/lld/dist-release_90: ELF docs
Dimitry Andric
dim at FreeBSD.org
Sat Sep 7 11:22:05 UTC 2019
Author: dim
Date: Sat Sep 7 11:22:03 2019
New Revision: 351987
URL: https://svnweb.freebsd.org/changeset/base/351987
Log:
Vendor import of lld release_90 branch r371301:
https://llvm.org/svn/llvm-project/lld/branches/release_90@371301
Modified:
vendor/lld/dist-release_90/ELF/Writer.cpp
vendor/lld/dist-release_90/docs/ReleaseNotes.rst
Modified: vendor/lld/dist-release_90/ELF/Writer.cpp
==============================================================================
--- vendor/lld/dist-release_90/ELF/Writer.cpp Sat Sep 7 11:22:01 2019 (r351986)
+++ vendor/lld/dist-release_90/ELF/Writer.cpp Sat Sep 7 11:22:03 2019 (r351987)
@@ -2230,25 +2230,27 @@ template <class ELFT> void Writer<ELFT>::fixSectionAli
// same with its virtual address modulo the page size, so that the loader can
// load executables without any address adjustment.
static uint64_t computeFileOffset(OutputSection *os, uint64_t off) {
- // File offsets are not significant for .bss sections. By convention, we keep
- // section offsets monotonically increasing rather than setting to zero.
- if (os->type == SHT_NOBITS)
- return off;
-
- // If the section is not in a PT_LOAD, we just have to align it.
- if (!os->ptLoad)
- return alignTo(off, os->alignment);
-
// The first section in a PT_LOAD has to have congruent offset and address
// module the page size.
- OutputSection *first = os->ptLoad->firstSec;
- if (os == first) {
- uint64_t alignment = std::max<uint64_t>(os->alignment, config->maxPageSize);
+ if (os->ptLoad && os->ptLoad->firstSec == os) {
+ uint64_t alignment =
+ std::max<uint64_t>(os->ptLoad->p_align, config->maxPageSize);
return alignTo(off, alignment, os->addr);
}
+ // File offsets are not significant for .bss sections other than the first one
+ // in a PT_LOAD. By convention, we keep section offsets monotonically
+ // increasing rather than setting to zero.
+ if (os->type == SHT_NOBITS)
+ return off;
+
+ // If the section is not in a PT_LOAD, we just have to align it.
+ if (!os->ptLoad)
+ return alignTo(off, os->alignment);
+
// If two sections share the same PT_LOAD the file offset is calculated
// using this formula: Off2 = Off1 + (VA2 - VA1).
+ OutputSection *first = os->ptLoad->firstSec;
return first->offset + os->addr - first->addr;
}
Modified: vendor/lld/dist-release_90/docs/ReleaseNotes.rst
==============================================================================
--- vendor/lld/dist-release_90/docs/ReleaseNotes.rst Sat Sep 7 11:22:01 2019 (r351986)
+++ vendor/lld/dist-release_90/docs/ReleaseNotes.rst Sat Sep 7 11:22:03 2019 (r351987)
@@ -8,11 +8,13 @@ lld 9.0.0 Release Notes
Introduction
============
-This document contains the release notes for the lld linker, release 9.0.0.
-Here we describe the status of lld, including major improvements
-from the previous release. All lld releases may be downloaded
-from the `LLVM releases web site <https://llvm.org/releases/>`_.
+lld is a high-performance linker that supports ELF (Unix), COFF
+(Windows), Mach-O (macOS), MinGW and WebAssembly. lld is
+command-line-compatible with GNU linkers and Microsoft link.exe and is
+significantly faster than the system default linkers.
+lld 9 has lots of feature improvements and bug fixes.
+
Non-comprehensive list of changes in this release
=================================================
@@ -22,53 +24,188 @@ ELF Improvements
* ld.lld now has typo suggestions for flags:
``$ ld.lld --call-shared`` now prints
``unknown argument '--call-shared', did you mean '--call_shared'``.
+ (`r361518 <https://reviews.llvm.org/rL361518>`_)
+* ``--allow-shlib-undefined`` and ``--no-allow-shlib-undefined``
+ options are added. ``--no-allow-shlib-undefined`` is the default for
+ executables.
+ (`r352826 <https://reviews.llvm.org/rL352826>`_)
+
+* ``-nmagic`` and ``-omagic`` options are fully supported.
+ (`r360593 <https://reviews.llvm.org/rL360593>`_)
+
+* Segment layout has changed. PT_GNU_RELRO, which was previously
+ placed in the middle of readable/writable PT_LOAD segments, is now
+ placed at the beginning of them. This change permits lld-produced
+ ELF files to be read correctly by GNU strip older than 2.31, which
+ has a bug to discard a PT_GNU_RELRO in the former layout.
+
+* ``-z common-page-size`` is supported.
+ (`r360593 <https://reviews.llvm.org/rL360593>`_)
+
+* Diagnostics messages have improved. A new flag ``--vs-diagnostics``
+ alters the format of diagnostic output to enable source hyperlinks
+ in Microsoft Visual Studio IDE.
+
+* Linker script compatibility with GNU BFD linker has generally improved.
+
+* The clang ``--dependent-library`` form of autolinking is supported.
+
+ This feature is added to implement the Windows-style autolinking for
+ Unix. On Unix, in order to use a library, you usually have to
+ include a header file provided by the library and then explicitly
+ link the library with the linker ``-l`` option. On Windows, header
+ files usually contain pragmas that list needed libraries. Compilers
+ copy that information to object files, so that linkers can
+ automatically link needed libraries. ``--dependent-library`` is
+ added for implementing that Windows semantics on Unix.
+ (`r360984 <https://reviews.llvm.org/rL360984>`_)
+
+* AArch64 BTI and PAC are supported.
+ (`r362793 <https://reviews.llvm.org/rL362793>`_)
+
* lld now supports replacing ``JAL`` with ``JALX`` instructions in case
- of MIPS - microMIPS cross-mode jumps.
+ of MIPS-microMIPS cross-mode jumps.
+ (`r354311 <https://reviews.llvm.org/rL354311>`_)
* lld now creates LA25 thunks for MIPS R6 code.
+ (`r354312 <https://reviews.llvm.org/rL354312>`_)
* Put MIPS-specific .reginfo, .MIPS.options, and .MIPS.abiflags sections
into corresponding PT_MIPS_REGINFO, PT_MIPS_OPTIONS, and PT_MIPS_ABIFLAGS
segments.
+* The quality of RISC-V and PowerPC ports have greatly improved. Many
+ applications can now be linked by lld. PowerPC64 is now almost
+ production ready.
+
+* The Linux kernel for arm32_7, arm64, ppc64le and x86_64 can now be
+ linked by lld.
+
+* x86-64 TLSDESC is supported.
+ (`r361911 <https://reviews.llvm.org/rL361911>`_,
+ `r362078 <https://reviews.llvm.org/rL362078>`_)
+
+* DF_STATIC_TLS flag is set for i386 and x86-64 when needed.
+ (`r353293 <https://reviews.llvm.org/rL353293>`_,
+ `r353378 <https://reviews.llvm.org/rL353378>`_)
+
+* The experimental partitioning feature is added to allow a program to
+ be split into multiple pieces.
+
+ The feature allows you to semi-automatically split a single program
+ into multiple ELF files called "partitions". Since all partitions
+ share the same memory address space and don't use PLT/GOT, split
+ programs run as fast as regular programs.
+
+ With the mechanism, you can start a program only with a "main"
+ partition and load remaining partitions on-demand. For example, you
+ can split a web browser into a main partition and a PDF reader
+ sub-partition and load the PDF reader partition only when a user
+ tries to open a PDF file.
+
+ See `the documentation <Partitions.html>`_ for more information.
+
+* If "-" is given as an output filename, lld writes the final result
+ to the standard output. Previously, it created a file "-" in the
+ current directory.
+ (`r351852 <https://reviews.llvm.org/rL351852>`_)
+
+* ``-z ifunc-noplt`` option is added to reduce IFunc function call
+ overhead in a freestanding environment such as the OS kernel.
+
+ Functions resolved by the IFunc mechanism are usually dispatched via
+ PLT and thus slower than regular functions because of the cost of
+ indirection. With ``-z ifunc-noplt``, you can eliminate it by doing
+ text relocations at load-time. You need a special loader to utilize
+ this feature. This feature is added for the FreeBSD kernel but can
+ be used by any operating systems.
+ (`r360685 <https://reviews.llvm.org/rL360685>`_)
+
+* ``--undefined-glob`` option is added. The new option is an extension
+ to ``--undefined`` to take a glob pattern instead of a single symbol
+ name.
+ (`r363396 <https://reviews.llvm.org/rL363396>`_)
+
+
COFF Improvements
-----------------
* Like the ELF driver, lld-link now has typo suggestions for flags.
+ (`r361518 <https://reviews.llvm.org/rL361518>`_)
-* lld-link now correctly reports duplicate symbol errors for obj files
- that were compiled with /Gy.
+* lld-link now correctly reports duplicate symbol errors for object
+ files that were compiled with ``/Gy``.
+ (`r352590 <https://reviews.llvm.org/rL352590>`_)
-* lld-link now correctly reports duplicate symbol errors when several res
- input files define resources with the same type, name, and language.
- This can be demoted to a warning using ``/force:multipleres``.
+* lld-link now correctly reports duplicate symbol errors when several
+ resource (.res) input files define resources with the same type,
+ name and language. This can be demoted to a warning using
+ ``/force:multipleres``.
+ (`r359829 <https://reviews.llvm.org/rL359829>`_)
-* lld-link now rejects more than one resource obj input files, matching
- link.exe. Previously, lld-link would silently ignore all but one.
- If you hit this: Don't pass resource obj files to the linker, instead pass
- res files to the linker directly. Don't put res files in static libraries,
- pass them on the command line.
+* lld-link now rejects more than one resource object input files,
+ matching link.exe. Previously, lld-link would silently ignore all
+ but one. If you hit this: Don't pass resource object files to the
+ linker, instead pass res files to the linker directly. Don't put
+ resource files in static libraries, pass them on the command line.
+ (`r359749 <https://reviews.llvm.org/rL359749>`_)
* Having more than two ``/natvis:`` now works correctly; it used to not
work for larger binaries before.
+ (`r327895 <https://reviews.llvm.org/rL327895>`_)
* Undefined symbols are now printed only in demangled form. Pass
``/demangle:no`` to see raw symbol names instead.
+ (`r355878 <https://reviews.llvm.org/rL355878>`_)
-* The following flags have been added: ``/functionpadmin``, ``/swaprun:``,
- ``/threads:no``
-
* Several speed and memory usage improvements.
-* Range extension thunks are now created for ARM64, if needed
-
* lld-link now supports resource object files created by GNU windres and
- MS cvtres, not only llvm-cvtres
+ MS cvtres, not only llvm-cvtres.
* The generated thunks for delayimports now share the majority of code
- among thunks, significantly reducing the overhead of using delayimport
+ among thunks, significantly reducing the overhead of using delayimport.
+ (`r365823 <https://reviews.llvm.org/rL365823>`_)
+* ``IMAGE_REL_ARM{,64}_REL32`` relocations are supported.
+ (`r352325 <https://reviews.llvm.org/rL352325>`_)
+
+* Range extension thunks for AArch64 are now supported, so lld can
+ create large executables for Windows/ARM64.
+ (`r352929 <https://reviews.llvm.org/rL352929>`_)
+
+* The following flags have been added:
+ ``/functionpadmin`` (`r354716 <https://reviews.llvm.org/rL354716>`_),
+ ``/swaprun:`` (`r359192 <https://reviews.llvm.org/rL359192>`_),
+ ``/threads:no`` (`r355029 <https://reviews.llvm.org/rL355029>`_),
+ ``/filealign`` (`r361634 <https://reviews.llvm.org/rL361634>`_)
+
+WebAssembly Improvements
+------------------------
+
+* Imports from custom module names are supported.
+ (`r352828 <https://reviews.llvm.org/rL352828>`_)
+
+* Symbols that are in llvm.used are now exported by default.
+ (`r353364 <https://reviews.llvm.org/rL353364>`_)
+
+* Initial support for PIC and dynamic linking has landed.
+ (`r357022 <https://reviews.llvm.org/rL357022>`_)
+
+* wasm-ld now add ``__start_``/``__stop_`` symbols for data sections.
+ (`r361236 <https://reviews.llvm.org/rL361236>`_)
+
+* wasm-ld now doesn't report an error on archives without a symbol index.
+ (`r364338 <https://reviews.llvm.org/rL364338>`_)
+
+* The following flags have been added:
+ ``--emit-relocs`` (`r361635 <https://reviews.llvm.org/rL361635>`_),
+ ``--wrap`` (`r361639 <https://reviews.llvm.org/rL361639>`_),
+ ``--trace`` and ``--trace-symbol``
+ (`r353264 <https://reviews.llvm.org/rL353264>`_).
+
+
MinGW Improvements
------------------
@@ -77,12 +214,18 @@ MinGW Improvements
DWARF exception handling with libgcc and gcc's crtend.o.
* lld now also handles DWARF unwind info generated by GCC, when linking
- with libgcc
+ with libgcc.
-* Many more GNU ld options are now supported, which e.g. allows the lld
- MinGW frontend to be called by GCC
-
* PDB output can be requested without manually specifying the PDB file
name, with the new option ``-pdb=`` with an empty value to the option.
(The old existing syntax ``-pdb <filename>`` was more cumbersome to use
with an empty parameter value.)
+
+* ``--no-insert-timestamp`` option is added as an alias to ``/timestamp:0``.
+ (`r353145 <https://reviews.llvm.org/rL353145>`_)
+
+* Many more GNU ld options are now supported, which e.g. allows the lld
+ MinGW frontend to be called by GCC.
+
+* The following options are added: ``--exclude-all-symbols``,
+ ``--appcontainer``, ``--undefined``
More information about the svn-src-all
mailing list