Commit Graph

90 Commits

Author SHA1 Message Date
Zequan Wu 763671f387 [COFF] Port CallGraphSort to COFF from ELF 2020-07-30 15:21:44 -07:00
Martin Storsjö 745eb02496 [LLD] [MinGW] Implement the --no-seh flag
Previously this flag was just ignored. If set, set the
IMAGE_DLL_CHARACTERISTICS_NO_SEH bit, regardless of the normal safeSEH
machinery.

In mingw configurations, the safeSEH bit might not be set in e.g. object
files built from handwritten assembly, making it impossible to use the
normal safeseh flag. As mingw setups don't generally use SEH on 32 bit
x86 at all, it should be fine to set that flag bit though - hook up
the existing GNU ld flag for controlling that.

Differential Revision: https://reviews.llvm.org/D84701
2020-07-28 21:08:37 +03:00
Martin Storsjö 7f0e6c31c2 [LLD] [COFF] Add options for disabling auto import and runtime pseudo relocs
Allow disabling either the full auto import feature, or just
forbidding the cases that require runtime fixups.

As long as all auto imported variables are referenced from separate
.refptr$<name> sections, we can alias them on top of the IAT entries
and don't actually need any runtime fixups via pseudo relocations.
LLVM generates references to variables in .refptr stubs, if it
isn't known that the variable for sure is defined in the same object
module. Runtime pseudo relocs are needed if the addresses of auto
imported variables are used in constant initializers though.

Fixing up runtime pseudo relocations requires the use of
VirtualProtect (which is disallowed in WinStore/UWP apps) or
VirtualProtectFromApp. To allow any risk of ambiguity, allow
rejecting cases that would require this at the linker stage.

This adds support for the --disable-runtime-pseudo-reloc and
--disable-auto-import options in the MinGW driver (matching GNU ld.bfd)
with corresponding lld private options in the COFF driver.

Differential Revision: https://reviews.llvm.org/D78923
2020-05-14 13:05:14 +03:00
Eric Astor a39b14f0b4 [ms] Add new /PDBSTREAM option to lld-link allowing injection of streams into PDB files.
Summary:
/PDBSTREAM:<name>=<file> adds the contents of <file> to stream <name> in the resulting PDB.

This allows native uses with workflows that (for example) add srcsrv streams to PDB files to provide a location for the build's source files.

Results should be equivalent to linking with lld-link, then running Microsoft's pdbstr tool with the command line:
pdbstr.exe -w -p:<PDB LOCATION> -s:<name> -i:<file>
except in cases where the named stream overlaps with a default named stream, such as "/names". In those cases, the added stream will be overridden, making the /pdbstream option a no-op.

Reviewers: thakis, rnk

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D77310
2020-04-07 16:19:38 -04:00
Fangrui Song eb4663d8c6 [lld][COFF][ELF][WebAssembly] Replace --[no-]threads /threads[:no] with --threads={1,2,...} /threads:{1,2,...}
--no-threads is a name copied from gold.
gold has --no-thread, --thread-count and several other --thread-count-*.

There are needs to customize the number of threads (running several lld
processes concurrently or customizing the number of LTO threads).
Having a single --threads=N is a straightforward replacement of gold's
--no-threads + --thread-count.

--no-threads is used rarely. So just delete --no-threads instead of
keeping it for compatibility for a while.

If --threads= is specified (ELF,wasm; COFF /threads: is similar),
--thinlto-jobs= defaults to --threads=,
otherwise all available hardware threads are used.

There is currently no way to override a --threads={1,2,...}. It is still
a debate whether we should use --threads=all.

Reviewed By: rnk, aganea

Differential Revision: https://reviews.llvm.org/D76885
2020-03-31 08:46:12 -07:00
Sylvain Audi b91905a263 [lld-link] Support /map option, matching link.exe 's /map output format
Added support for /map and /map:[filepath].
The output was derived from Microsoft's Link.exe output when using that same option.
Note that /MAPINFO support was not added.

The previous implementation of MapFile.cpp/.h was meant for /lldmap, and was renamed to LLDMapFile.cpp/.h
MapFile.cpp/.h is now for /MAP
However, a small fix was added to lldmap, replacing a std::sort with std::stable_sort to enforce reproducibility.

Differential Revision: https://reviews.llvm.org/D70557
2020-03-24 09:48:00 -04:00
Rui Ueyama a2923b2a1e Implement CET Shadow Stack (Intel Controlflow Enforcement Technology) support on Windows
Patch by Petr Penzin.

Windows support for CET is limited to shadow stack, which is enabled
by setting a PE bit in the linker.

Docs:

MSVC linker flag:
https://docs.microsoft.com/en-us/cpp/build/reference/cetcompat?view=vs-2019

IMAGE_DLLCHARACTERISTICS_EX_CET_COMPAT PE bit:
https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#extended-dll-characteristics

Differential Revision: https://reviews.llvm.org/D70606
2020-03-16 17:51:32 +09:00
Reid Kleckner 8045a8a7f1 [COFF] Warn that LLD does not support /PDBSTRIPPED:
Doesn't really fix PR44491, but it avoids treating it as an input.
2020-01-15 15:11:19 -08:00
Rui Ueyama f95ed69641 Implement /driver, /driver:wdm and /driver:uponly
This patch implements /driver, /driver:wdm and /driver:uponly as
described in
https://docs.microsoft.com/en-us/cpp/build/reference/driver-windows-nt-kernel-mode-driver?view=vs-2019.

Differential Revision: https://reviews.llvm.org/D70162
2019-11-14 13:07:56 +09:00
Rui Ueyama 0d53ac8096 Add /reproduce option to lld/COFF
This patch adds /reproduce:<path> option to lld/COFF. This is an
lld-specific option, so we can name it freely. I chose /reproduce
over other names (e.g. /lldlinkrepro) for consistency with other lld
ports.

Differential Revision: https://reviews.llvm.org/D68381

llvm-svn: 373704
2019-10-04 07:27:38 +00:00
Nico Weber c7d8cc48c1 lld-link: Make Options.td formatting more self-consistent.
Also tighten up help strings for /force, --start-lib, and --end-lib.

Differential Revision: https://reviews.llvm.org/D67457

llvm-svn: 371927
2019-09-14 23:41:42 +00:00
Nico Weber d48ea5da94 lld-link: Add a flag /lldignoreenv that makes lld-link ignore env vars.
This is useful for enforcing that builds are independent of the
environment; it can be used when all system library paths are added
via /libpath: already. It's similar ot cl.exe's /X flag.

Since it should also affect %LINK% (the other caller of
`Process::GetEnv` in lld/COFF), the early-option-parsing needs
to move around a bit. The options are:

- Add a manual loop over the argv ArrayRef and look for "/lldignoreenv".
  This repeats the name of the flag in both Options.td and in
  DriverUtils.cpp.

- Add yet another table.ParseArgs() call just for /lldignoreenv before
  adding %LINK%.

- Use the existing early ParseArgs() that's there for --rsp-quoting and use
  it for /lldignoreenv for %LINK% as well. This means --rsp-quoting
  and /lldignoreenv can't be passed via %LINK%.

I went with the third approach.

Differential Revision: https://reviews.llvm.org/D67456

llvm-svn: 371852
2019-09-13 13:13:52 +00:00
Bob Haarman 7dc5e7a0a4 reland "[lld-link] implement -start-lib and -end-lib"
Summary:
This is a re-land of r370487 with a fix for the use-after-free bug
that rev contained.

This implements -start-lib and -end-lib flags for lld-link, analogous
to the similarly named options in ld.lld. Object files after
-start-lib are included in the link only when needed to resolve
undefined symbols. The -end-lib flag goes back to the normal behavior
of always including object files in the link. This mimics the
semantics of static libraries, but without needing to actually create
the archive file.

Reviewers: ruiu, smeenai, MaskRay

Reviewed By: ruiu, MaskRay

Subscribers: akhuang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66848

llvm-svn: 370816
2019-09-03 20:32:16 +00:00
Vlad Tsyrklevich 802aab5de8 Revert "[lld-link] implement -start-lib and -end-lib"
This reverts commit r370487 as it is causing ASan/MSan failures on
sanitizer-x86_64-linux-fast

llvm-svn: 370550
2019-08-30 23:24:41 +00:00
Bob Haarman fd7569c8e3 [lld-link] implement -start-lib and -end-lib
Summary:
This implements -start-lib and -end-lib flags for lld-link, analogous
to the similarly named options in ld.lld. Object files after
-start-lib are included in the link only when needed to resolve
undefined symbols. The -end-lib flag goes back to the normal behavior
of always including object files in the link. This mimics the
semantics of static libraries, but without needing to actually create
the archive file.

Reviewers: ruiu, smeenai, MaskRay

Reviewed By: ruiu, MaskRay

Subscribers: akhuang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66848

llvm-svn: 370487
2019-08-30 16:50:10 +00:00
Bob Haarman 5375b94e36 [lld-link] implement -lto-obj-path
Summary:
This adds the -lto-obj-path option to lld-link. This can be
used to specify a path at which to write a native object file for
the full LTO part when using LTO unit splitting.

Reviewers: ruiu, tejohnson, pcc, rnk

Reviewed By: ruiu, rnk

Subscribers: mehdi_amini, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65964

llvm-svn: 369559
2019-08-21 18:24:59 +00:00
Bob Haarman 5011b83237 [lld-link] implement -thinlto-{prefix,object-suffix}-replace
Summary:
Adds the following two options to lld-link:

-thinlto-prefix-replace: allows replacing a prefix in paths generated
for ThinLTO. This can be used to ensure index files and native object
files are stored in unique directories, allowing multiple distributed
ThinLTO links to proceed concurrently.

-thinlto-object-suffix-replace: allows replacing a suffix in object
file paths involved in ThinLTO. This allows minimized index files to
be used for the thin link while storing the paths to the full bitcode
files for subsequent steps (code generation and final linking).

Reviewers: ruiu, tejohnson, pcc, rnk

Subscribers: mehdi_amini, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64542

llvm-svn: 365807
2019-07-11 18:48:58 +00:00
Bob Haarman 63efb28f47 [lld-link] implement -thinlto-index-only
Summary:
This implements -thinlto-index-only, -thinlto-index-only:,
and -thinlto-emit-imports-files options in lld-link. They are
analogous to their counterparts in ld.lld: -thinlto-index-only
causes us to perform ThinLTO's thin link and write index files,
but not perform code generation. -thinlto-index-only: does the
same, but also writes a text file listing the native object
files expected to be generated. -thinlto-emit-imports-files
creates a text file next to each index file, listing the files
to import from.

Reviewers: ruiu, tejohnson, pcc, rnk

Subscribers: mehdi_amini, steven_wu, dexonsmith, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64461

llvm-svn: 365800
2019-07-11 18:03:14 +00:00
Martin Storsjo c02f6bf07f [COFF] Add an lld specific option /includeoptional
This works like /include, but is not fatal if the requested symbol
wasn't found. This allows implementing the GNU ld option -u.

Differential Revision: https://reviews.llvm.org/D62976

llvm-svn: 362881
2019-06-08 18:26:18 +00:00
Rui Ueyama 74de6203ef [LLD][COFF] Implement /filealign parameter
Patch by Stefan Schmidt.

This adds the /filealign parameter to lld, which allows to specify the
section alignment in the output file (as it does on Microsoft's
link.exe).

This is required to be able to load dynamically linked libraries on the
original Xbox, where the debugger monitor expects the section alignment
in the file to be the same as in memory.

llvm-svn: 361634
2019-05-24 12:42:36 +00:00
Nico Weber 4b81e9f8d1 lld-link: Allow /? as option prefix, like -? is allowed
link.exe seems to allow `/?foo` and `-?foo` in addition to `/foo` and `-foo`.

Since lld-link already supports the `-?foo` spelling, support `/?foo` as well.

Differential Revision: https://reviews.llvm.org/D61375

llvm-svn: 360150
2019-05-07 14:15:35 +00:00
Nico Weber 81862f82ee lld-link: Add /force:multipleres extension to make dupe resource diag non-fatal
As a side benefit, lld-link now reports more than one duplicate resource
entry before exiting with an error even if the new flag is not passed.

llvm-svn: 359829
2019-05-02 21:21:55 +00:00
Nico Weber c0838af754 lld-link: Implement /swaprun: flag
r191276 added this to old LLD, but it never made it to new LLD -- except
that the flag was in Options.td, so it was silently ignored. I figured
it should be easy to implement, so I did that instead of removing the
flags from Options.td.

I then discovered that link.exe also supports comma-separated lists of
'cd' and 'net', which made the parsing code a bit annoying.

The Alias technique in Options.td is to get nice help output.

Differential Revision: https://reviews.llvm.org/D61067

llvm-svn: 359192
2019-04-25 14:02:26 +00:00
Alexandre Ganea 3e60ee9f10 [LLD][COFF] Add /summary to print statistics
/summary prints information about the data (OBJ/LIB/PDB) processed by LLD. The goal is have an estimate about the inputs and outputs, to better understand where the timings go.

Differential Revision: https://reviews.llvm.org/D58599

llvm-svn: 356188
2019-03-14 18:45:08 +00:00
Nico Weber 020d92cb61 lld-link: Only print demangled symbol names by default
This makes lld-link's output a bit more concise. Since most developers can't
read mangled names, this should make the output a bit easier to understand as
well. It also makes lld-link's output consistent with ld.lld's output.

(link.exe prints both demangled and mangled names; lld-link used to match
link.exe output but now no longer does.)

For people working on toolchains, add a `/demangle:no` flag that makes lld-link
print the mangled name instead of the demangled name. (If desired, people could
pipe that through `demumble -b` to get the old behavior of both demangled and
mangled output.)

Differential Revision: https://reviews.llvm.org/D58132

llvm-svn: 355878
2019-03-11 23:02:18 +00:00
Alexandre Ganea 97b2b0636b [LLD][COFF] Support /threads[:no] like the ELF driver
Differential review: https://reviews.llvm.org/D58594

llvm-svn: 355029
2019-02-27 20:53:50 +00:00
Alexandre Ganea d307c4c47f [LLD][COFF] Add support for /FUNCTIONPADMIN command-line option
Initial patch by Stefan Reinalter.

Fixes PR36775

Differential Revision: https://reviews.llvm.org/D49366

llvm-svn: 354716
2019-02-23 01:46:18 +00:00
Martin Storsjo 272d8c18e0 [COFF] Add -exclude-all-symbols for MinGW
This is a private undocumented option, intended to be used by
the MinGW driver frontend.

Also restructure the condition to put if (Config->MinGW) first.
This changes the behaviour for the tautological combination of
-export-all-symbols without -lldmingw.

Differential Revision: https://reviews.llvm.org/D58380

llvm-svn: 354386
2019-02-19 21:57:44 +00:00
Nico Weber 64fb85c907 lld-link: Add help strings for /manifest, /nodefaultlib, /noentry; tweak manifest help strings
My main motivation is that I can never remember /nodefaultlib and
`lld-link /? | grep no` didn't display it due to it not having a help string.

Differential Revision: https://reviews.llvm.org/D56502

llvm-svn: 350750
2019-01-09 19:18:03 +00:00
Will Wilson 3cb18346d7 [lld-link] Generalize handling of /debug and /debug:{none,full,fastlink,ghash,symtab}
Implement final argument precedence if multiple /debug arguments are passed on the command-line to match expected link.exe behavior.
Support /debug:none and emit warning for /debug:fastlink with automatic fallback to /debug:full.
Emit error if last /debug:option is unknown.
Emit warning if last /debugtype:option is unknown.

https://reviews.llvm.org/D50404

llvm-svn: 342894
2018-09-24 15:28:03 +00:00
Rui Ueyama 11ca38f421 COFF: Add support for /force:multiple option
Patch by Thomas Roughton.

This patch adds support for linking with multiple definitions to LLD's
COFF driver, in line with link.exe's /force:multiple option.

Differential Revision: https://reviews.llvm.org/D50598

llvm-svn: 342191
2018-09-13 22:05:10 +00:00
Nico Weber 11f14904d3 lld-link: Remove /msvclto option
This was useful for LTO bringup in lld-link while lld couldn't write PDBs. Now
that it can, this should no longer be needed. Hopefully the flag is obscure
enough and recent enough, that nobody uses it – but if somebody should use it,
they should be able to just stop passing it and things should continue to work.

https://reviews.llvm.org/D50139

llvm-svn: 338615
2018-08-01 19:00:49 +00:00
Takuto Ikuta d855928ec3 [PDB] Add PDBSourcePath flag to support absolutize source file path
This patch changes relative path for source files in obj files to
absolute path in PDB when linking with added flag.

I will make obj file generated by clang-cl independent from build
directory for chromium build. But I don't want to confuse visual studio
debugger or require additional configuration. To attain this goal, I
added flag to convert relative source file path in obj to absolute path
when emitting PDB.

By removing absolute path from obj files, we can share build cache
between chromium developers even when they are doing debug build.
That will make build time faster.

More context:
https://bugs.chromium.org/p/chromium/issues/detail?id=712796
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/5HXSVX-7fPc

llvm-svn: 337439
2018-07-19 04:56:22 +00:00
Nico Weber c421fe5ef4 lld-link: Add /lib to Options.td so that it appears in lld-link's help output.
https://reviews.llvm.org/D49319

llvm-svn: 337086
2018-07-14 04:07:51 +00:00
Martin Storsjo 3a7905b2aa [COFF] Add an LLD specific option -debug:symbtab
With this set, we retain the symbol table, but skip the actual debug
information.

This is meant to be used by the MinGW frontend.

Differential Revision: https://reviews.llvm.org/D48745

llvm-svn: 335946
2018-06-29 06:08:25 +00:00
Nico Weber d657c25649 lld-link: Implement /INTEGRITYCHECK flag
/INTEGRITYCHECK has the effect of setting
IMAGE_DLLCHARACTERISTICS_FORCE_INTEGRITY. Fixes PR31066.
https://reviews.llvm.org/D47472

llvm-svn: 333652
2018-05-31 13:43:02 +00:00
Zachary Turner c8dd6ccc8a [COFF] Add /Brepro and /TIMESTAMP options.
Previously we would always write a hash of the binary into the
PE file, for reproducible builds.  This breaks AppCompat, which
is a feature of Windows that relies on the timestamp in the PE
header being set to a real value (or at the very least, a value
that satisfies certain properties).

To address this, we put the old behavior of writing the hash
behind the /Brepro flag, which mimics MSVC linker behavior.  We
also match MSVC default behavior, which is to write an actual
timestamp to the PE header.  Finally, we add the /TIMESTAMP
option (an lld extension) so that the user can specify the exact
value to be used in case he/she manually constructs a value which
is both reproducible and satisfies AppCompat.

Differential Revision: https://reviews.llvm.org/D46966

llvm-svn: 332613
2018-05-17 15:11:01 +00:00
Nico Weber cac2b3349e lld-link: Add --color-diagnostics(={always,never,auto})?, --no-color-diagnostics flags.
This is most useful when using lld-link on a non-Win host (but it might become
useful on Windows too if lld also grows a fansi-escape-codes flag).

Also make the help for --color-diagnostic mention the valid values in ELF and
wasm, and print the flag name with two dashes in diags, since the one-dash form
is seen as a list of many one-letter flags in some contexts.

https://reviews.llvm.org/D46693

llvm-svn: 332012
2018-05-10 18:19:02 +00:00
Zachary Turner d6fce2e9db [COFF] Alias /DEBUG:FULL to /DEBUG
With MSVC linker, /DEBUG is an alias of /DEBUG:FASTLINK, and if
you don't want /DEBUG:FASTLINK you have to explicitly specify
/DEBUG:FULL.

LLD doesn't support /DEBUG:FASTLINK, and so our standard /DEBUG
option is what MSVC calls /DEBUG:FULL.  To provide command line
compatibility with MSVC, we should also support /DEBUG:FULL, and
since it's the same as what LLD already does for /DEBUG, just
alias it.

llvm-svn: 330647
2018-04-23 20:54:08 +00:00
Peter Collingbourne c8f5c05d41 COFF: Document /pdbaltpath.
llvm-svn: 330488
2018-04-20 22:11:28 +00:00
Zachary Turner f228276262 [PDB] Resubmit "Support embedding natvis files in PDBs."
This was reverted several times due to what ultimately turned out
to be incompatibilities in our serialized hash table format.

Several changes went in prior to this to fix those issues since
they were more fundamental and independent of supporting injected
sources, so now that those are fixed this change should hopefully
pass.

llvm-svn: 328363
2018-03-23 19:57:25 +00:00
Zachary Turner fced530650 Revert "Resubmit "Support embedding natvis files in PDBs.""
This is still failing on a different bot this time due to some
issue related to hashing absolute paths.  Reverting until I can
figure it out.

llvm-svn: 328014
2018-03-20 18:37:03 +00:00
Zachary Turner 132d7a134f Resubmit "Support embedding natvis files in PDBs."
The issue causing this to fail in certain configurations
should be fixed.

It was due to the fact that DIA apparently expects there to be
a null string at ID 1 in the string table.  I'm not sure why this
is important but it seems to make a difference, so set it.

llvm-svn: 328002
2018-03-20 17:06:39 +00:00
Zachary Turner a21558897b Revert "Support embedding natvis files in PDBs."
This is causing a test failure on a certain bot, so I'm removing
this temporarily until we can figure out the source of the error.

llvm-svn: 327903
2018-03-19 20:41:59 +00:00
Zachary Turner de53aaf132 Support embedding natvis files in PDBs.
Natvis is a debug language supported by Visual Studio for
specifying custom visualizers.  The /NATVIS option is an
undocumented link.exe flag which will take a .natvis file
and "inject" it into the PDB.  This way, you can ship the
debug visualizers for a program along with the PDB, which
is very useful for postmortem debugging.

This is implemented by adding a new "named stream" to the
PDB with a special name of /src/files/<natvis file name>
and simply copying the contents of the xml into this file.

Additionally, we need to emit a single stream named
/src/headerblock which contains a hash table of embedded
files to records describing them.

This patch adds this functionality, including the /NATVIS
option to lld-link.

Differential Revision: https://reviews.llvm.org/D44328

llvm-svn: 327895
2018-03-19 19:53:51 +00:00
Martin Storsjo 5351891b55 [COFF] Add support for the GNU ld flag --kill-at
GNU ld has got a number of different flags for adjusting how to
behave around stdcall functions. The --kill-at flag strips the
trailing sdcall suffix from exported functions (which otherwise
is included by default in MinGW setups).

This also strips it from the corresponding import library though.
That makes it hard to link to such an import library from code
that calls the functions - but this matches what GNU ld does with
this flag. Therefore, this flag is probably not sensibly used
together with import libraries, but probably mostly when creating
some sort of plugin, or if creating the import library separately
with dlltool.

Differential Revision: https://reviews.llvm.org/D44292

llvm-svn: 327561
2018-03-14 20:17:16 +00:00
Reid Kleckner af2f7da74c [COFF] Add minimal support for /guard:cf
Summary:
This patch adds some initial support for Windows control flow guard. At
the end of the day, the linker needs to synthesize a table of RVAs very
similar to the structured exception handler table (/safeseh).

Both /safeseh and /guard:cf take sections of symbol table indices
(.sxdata and .gfids$y) and turn them into RVA tables referenced by the
load config struct in the CRT through special symbols.

Reviewers: ruiu, amccarth

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42592

llvm-svn: 324306
2018-02-06 01:58:26 +00:00
Bob Haarman 5ec448516d [COFF] make /incremental control overwriting unchanged import libraries
Summary:
r323164 made lld-link not overwrite import libraries when their
contents haven't changed. MSVC's link.exe does this only when
performing incremental linking. This change makes lld-link's import
library overwriting similarly dependent on whether or not incremental
linking is being performed. This is controlled by the /incremental or
/incremental:no options. In addition, /opt:icf, /opt:ref, and /order
turn off /incremental and issue a warning if /incremental was
specified on the command line.

Reviewers: rnk, ruiu, zturner

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42716

llvm-svn: 323930
2018-01-31 23:44:00 +00:00
Rui Ueyama 57175aa1e9 Add the /order option.
With the /order option, you can give an order file. An order file
contains symbol names, one per line, and the linker places comdat
sections in that given order. The option is used often to optimize
an output binary for (in particular, startup) speed by improving
locality.

Differential Revision: https://reviews.llvm.org/D42598

llvm-svn: 323579
2018-01-27 00:34:46 +00:00
Zachary Turner 727f153b6f [coff] Print detailed timing information with /TIME.
The classes used to print and update time information are in
common, so other linkers could use this as well if desired.

Differential Revision: https://reviews.llvm.org/D41915

llvm-svn: 322736
2018-01-17 19:16:26 +00:00