Commit Graph

1096 Commits

Author SHA1 Message Date
Peter Collingbourne b6c5a3045b COFF: Allow ICF on vtable sections.
Differential Revision: https://reviews.llvm.org/D46734

llvm-svn: 332059
2018-05-10 23:31:58 +00:00
Peter Collingbourne e28faed768 COFF: Don't create unnecessary thunks.
A thunk is only needed if a relocation points to the undecorated
import name.

Differential Revision: https://reviews.llvm.org/D46673

llvm-svn: 332019
2018-05-10 19:01:28 +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
Martin Storsjo 5c84d442f5 [COFF] Fix dangling StringRefs from SVN 331900
llvm-svn: 331912
2018-05-09 19:07:10 +00:00
Martin Storsjo 0ca06f7950 [COFF] Allow specifying export forwarding in a def file
Previously this was only supported when specified on the command line
or in directives.

Differential Revision: https://reviews.llvm.org/D46244

llvm-svn: 331900
2018-05-09 18:19:41 +00:00
Martin Storsjo 97379ff6b2 [COFF] Improve correctness of def parsing for GNU features
The operator == used for exporting a function with a different
name in the DLL compared to the name in the import library
(which is useful for adding linker level aliases for function
in the import library) is a feature distinct and different from
the operator = used for exporting a function with a different
name (both in import library and DLL) than in the implementation
producing the DLL.

When creating an import library using dlltool, from a def file that
contains forwards (Func = OtherDll.Func), this shouldn't affect the
produced import library, which should still behave just as if it
was a normal exported function.

This clears a lot of confusion and subtle misunderstandings, and
avoids a parameter that was used to avoid creating weak aliases
when invoked from lld. (This parameter was added previously due to
the existing conflation of the two features.)

Differential Revision: https://reviews.llvm.org/D46245

llvm-svn: 331860
2018-05-09 09:22:03 +00:00
Martin Storsjo cc80776eff [COFF] Implement the remaining ARM64 relocations
Now only IMAGE_REL_ARM64_ABSOLUTE and IMAGE_REL_ARM64_TOKEN
are unhandled.

Also add range checks for the existing BRANCH26 relocation.

Differential Revision: https://reviews.llvm.org/D46354

llvm-svn: 331505
2018-05-04 06:06:27 +00:00
Bob Haarman 947647d0c1 [COFF] more informative "broken object file" diagnostics
Summary:
When a symbol refers to a special section or a section that doesn't
exist, lld would fatal with "broken object file". This change gives a
different message for each scenario, and includes the name of the
file, name of the symbol, and the section being referred to.

Reviewers: pcc, ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46090

llvm-svn: 330883
2018-04-25 23:33:19 +00:00
Hans Wennborg 03ca8f4fd0 [COFF] Don't set the tsaware bit on DLLs
It doesn't apply to DLLs, and link.exe doesn't set it.

Differential Revision: https://reviews.llvm.org/D46077

llvm-svn: 330868
2018-04-25 20:32:00 +00:00
Bob Haarman 8832f88996 [COFF] create MemoryBuffers without requiring NUL terminators
Summary:
In a number of places in the COFF linker, we were calling
MemoryBuffer::getFile() with default parameters. This causes LLVM to
NUL-terminate the buffers, which can prevent them from being memory
mapped. Since we operate on binary and do not use NUL as an indicator
of the end of the file content, this change causes us to not require
the NUL terminator anymore.

Reviewers: ruiu, pcc

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45909

llvm-svn: 330786
2018-04-24 23:16:39 +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
Bob Haarman 8679a7ecea Fix nullptr passed to memcpy in lld/COFF/Chunks.cpp
Summary:
ubsan found that we sometimes pass nullptr to memcpy in
SectionChunk::writeTo(). This change adds a check that avoids that.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45789

llvm-svn: 330490
2018-04-20 22:16:09 +00:00
Peter Collingbourne c8f5c05d41 COFF: Document /pdbaltpath.
llvm-svn: 330488
2018-04-20 22:11:28 +00:00
Peter Collingbourne 3d636edc56 COFF: Merge .xdata into .rdata by default.
Differential Revision: https://reviews.llvm.org/D45804

llvm-svn: 330484
2018-04-20 21:32:37 +00:00
Peter Collingbourne 326f419335 COFF: Merge .bss into .data by default.
Differential Revision: https://reviews.llvm.org/D45803

llvm-svn: 330483
2018-04-20 21:30:36 +00:00
Peter Collingbourne 71c7de5b77 COFF: Preserve section type when processing /section flag.
It turns out that we were dropping this before.

Differential Revision: https://reviews.llvm.org/D45802

llvm-svn: 330481
2018-04-20 21:23:16 +00:00
Peter Collingbourne 381b3d8aa3 COFF: Use (name, output characteristics) as a key when grouping input sections into output sections.
This is what link.exe does and lets us avoid needing to worry about
merging output characteristics while adding input sections to output
sections.

With this change we can't process /merge in the same way as before
because sections with different output characteristics can still
be merged into one another. So this change moves the processing of
/merge to just before we assign addresses. In the case where there
are multiple output sections with the same name, link.exe only merges
the first section with the source name into the first section with
the target name, and we do the same.

At the same time I also implemented transitive merging (which means
that /merge:.c=.b /merge:.b=.a merges both .c and .b into .a).

This isn't quite enough though because link.exe has a special case for
.CRT in 32-bit mode: it processes sections whose output characteristics
are DATA | R | W as though the output characteristics were DATA | R
(so that they get merged into things like constructor lists in the
expected way). Chromium has a few such sections, and it turns out
that those sections were causing the problem that resulted in r318699
(merge .xdata into .rdata) being reverted: because of the previous
permission merging semantics, the .CRT sections were causing the entire
.rdata section to become writable, which caused the SEH runtime to
crash because it apparently requires .xdata to be read-only. This
change also implements the same special case.

This should unblock being able to merge .xdata into .rdata by default,
as well as .bss into .data, both of which will be done in followups.

Differential Revision: https://reviews.llvm.org/D45801

llvm-svn: 330479
2018-04-20 21:10:33 +00:00
Zachary Turner 041eb6fef6 [LLD/PDB] Remove improper assert.
It's possible to have an empty object file, for example if you
just compile an empty .c file.  This file won't have any sections
so asserting that a file has chunks is definitely wrong.

llvm-svn: 330461
2018-04-20 18:36:51 +00:00
Zachary Turner 194be871b9 [LLD/PDB] Emit first section contribution for DBI Module Descriptor.
Part of the DBI stream is a list of variable length structures
describing each module that contributes to the final executable.

One member of this structure is a section contribution entry that
describes the first section contribution in the output file for
the given module.

We have been leaving this structure unpopulated until now, so with
this patch it is now filled out correctly.

Differential Revision: https://reviews.llvm.org/D45832

llvm-svn: 330457
2018-04-20 18:00:46 +00:00
Peter Collingbourne be084eca5b COFF: Remove OutputSection::getPermissions() and getCharacteristics().
All callers can just access the header directly.

Differential Revision: https://reviews.llvm.org/D45800

llvm-svn: 330367
2018-04-19 21:48:37 +00:00
Peter Collingbourne fa322abee9 COFF: Rename Chunk::getPermissions to getOutputCharacteristics.
In an upcoming change I will need to make a distinction between section
type (code, data, bss) and permissions. The term that I use for both
of these things is "output characteristics".

Differential Revision: https://reviews.llvm.org/D45799

llvm-svn: 330361
2018-04-19 20:03:24 +00:00
Reid Kleckner 8f1a28f190 [COFF] Mark images with no exception handlers for /safeseh
Summary:
DLLs and executables with no exception handlers need to be marked with
IMAGE_DLL_CHARACTERISTICS_NO_SEH, even if they have a load config.

Discovered here when building Chromium with LLD on Windows:
https://crbug.com/833951

Reviewers: ruiu, mstorsjo

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45778

llvm-svn: 330300
2018-04-18 22:37:10 +00:00
Peter Collingbourne 3108802f16 COFF: Friendlier undefined symbol errors.
Summary:
This change does three things:
- Try to find the file and line number of an undefined symbol
  reference by reading codeview debug info.
- Try to find the name of the function or global variable with the
  undefined symbol reference by searching the object file's symbol
  table.
- Prints the information in the same style as the ELF linker.

Differential Revision: https://reviews.llvm.org/D45467

llvm-svn: 330235
2018-04-17 23:32:33 +00:00
Peter Collingbourne 66f1c9a858 Reland r330223, "COFF: Merge .idata, .didat and .edata into .rdata by default.", which was reverted in r330228.
In this reland I removed an unnecessary use of /debug in the test
delayimports32.test and used the /pdbaltpath flag in the test
pdb-publics-import.test, both of which avoid embedding absolute PDB
paths in executables which could affect later RVAs.

Original commit message:
> COFF: Merge .idata, .didat and .edata into .rdata by default.
>
> This saves a little space and matches what link.exe does.
>
> Tested using the chromium Windows trybots:
> https://chromium-review.googlesource.com/c/chromium/src/+/1014784

Differential Revision: https://reviews.llvm.org/D45737

llvm-svn: 330233
2018-04-17 23:28:52 +00:00
Peter Collingbourne 94aa62e48a COFF: Implement /pdbaltpath flag.
I needed to revert r330223 because we were embedding an absolute PDB
path in the .rdata section, which ended up being laid out before the
.idata section and affecting its RVAs. This flag will let us control
the embedded path.

Differential Revision: https://reviews.llvm.org/D45747

llvm-svn: 330232
2018-04-17 23:28:38 +00:00
Peter Collingbourne 1254f3e77c Revert r330223, "COFF: Merge .idata, .didat and .edata into .rdata by default."
Seems to have uncovered some sort of non-determinism on the bots.

llvm-svn: 330228
2018-04-17 22:16:39 +00:00
Peter Collingbourne 09e0e2e656 COFF: Merge .idata, .didat and .edata into .rdata by default.
This saves a little space and matches what link.exe does.

Tested using the chromium Windows trybots:
https://chromium-review.googlesource.com/c/chromium/src/+/1014784

Differential Revision: https://reviews.llvm.org/D45737

llvm-svn: 330223
2018-04-17 21:44:31 +00:00
Peter Collingbourne 2f6d00612d COFF: Make SectionChunk::Relocs field an ArrayRef. NFCI.
Differential Revision: https://reviews.llvm.org/D45714

llvm-svn: 330172
2018-04-17 01:54:34 +00:00
Zachary Turner d8d97de514 [PDB] Correctly use the target machine when writing DBI stream.
Using Config->is64() will treat ARM64 as Amd64, which is incorrect.
Furthermore, there are more esoteric architectures that could
theoretically be encountered.  Just set it directly to the machine
type, which we already know anyway.

llvm-svn: 330157
2018-04-16 20:42:06 +00:00
Zachary Turner e3fe669855 Resubmit "Fix some incorrect fields in our generated PDBs."
This fixes the failing tests.  They simply hadn't been updated
to match the new output resulting from this patch.

llvm-svn: 330145
2018-04-16 18:17:13 +00:00
Zachary Turner 52c80e3860 Revert "Fix some incorrect fields in our generated PDBs."
There are a couple of failing tests which slipped under my radar
so I'm reverting this while I attempt to fix.

llvm-svn: 330133
2018-04-16 16:55:41 +00:00
Zachary Turner 1b06cc7817 Fix some incorrect fields in our generated PDBs.
Most of these are pretty trivial and obvious. Setting the toolchain
version to 14.11 is perhaps a little questionable, but we've been bitten
in the past where one of our version fields sidn't match MSVC's, and I
definitely don't want to go through that diagnosis again as it was
pretty time consuming and hard to track down.

I found all of these by using llvm-pdbutil export to dump the dbi and
pdb streams to a file, then using fc followed by llvm-pdbutil explain to
explain the mismatched bytes.

There are still some more, these are just the low hanging fruit.

Differential Revision: https://reviews.llvm.org/D45276

llvm-svn: 330130
2018-04-16 16:27:49 +00:00
Sam Clegg d11b6edfc8 Remove references to old SymbolBody class
Differential Revision: https://reviews.llvm.org/D45400

llvm-svn: 329846
2018-04-11 19:52:53 +00:00
Nico Weber fb64730005 s/LLVM_ON_WIN32/_WIN32/, lld
LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in             
HandleLLVMOptions.cmake, which is where _WIN32 defined too.  Just use the        
default macro instead of a reinvented one.                                       
                                                                                 
See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.   
No intended behavior change. 

llvm-svn: 329696
2018-04-10 13:15:21 +00:00
Peter Collingbourne bdfa127c3e COFF: Remove dead code. NFCI.
Differential Revision: https://reviews.llvm.org/D45423

llvm-svn: 329609
2018-04-09 19:46:00 +00:00
Peter Collingbourne 4902508934 COFF: Process /merge flag as we create output sections.
With this we can merge builtin sections.

Differential Revision: https://reviews.llvm.org/D45350

llvm-svn: 329471
2018-04-07 00:46:55 +00:00
Peter Collingbourne f2c0f39b91 COFF: Create output sections early. NFCI.
With this, all output sections are created in one place. This will make
it simpler to implement merging of builtin sections.

Differential Revision: https://reviews.llvm.org/D45349

llvm-svn: 329370
2018-04-06 03:25:49 +00:00
Peter Collingbourne 05f0bae318 COFF: Sort non-discardable sections at the same time as other sections. NFC.
This makes the sort order a little clearer.

Differential Revision: https://reviews.llvm.org/D45282

llvm-svn: 329227
2018-04-04 20:30:37 +00:00
Hans Wennborg 9a9fc78744 COFF: Layout sections in the same order as link.exe
One place where this seems to matter is to make sure the .rsrc section comes
after .text. The Win32 UpdateResource() function can change the contents of
.rsrc. It will move the sections that come after, but if .text gets moved, the
entry point header will not get updated and the executable breaks. This was
found by a test in Chromium.

Differential Revision: https://reviews.llvm.org/D45260

llvm-svn: 329221
2018-04-04 19:15:55 +00:00
Nico Weber a764379458 [lld-link] Add comment explaining that /FIXED behavior is correct despite contradicting MSDN.
Also add a test for /FIXED.
https://reviews.llvm.org/D45087

llvm-svn: 328879
2018-03-30 17:17:04 +00:00
Nico Weber 0945ad6643 [lld-link] Let /PROFILE imply /OPT:REF /OPT:NOICF /INCREMENTAL:NO /FIXED:NO
/FIXED:NO is always the default, so that part needs no work.

Also test the interaction of /ORDER: with /INCREMENTAL.

https://reviews.llvm.org/D45091

llvm-svn: 328877
2018-03-30 17:14:50 +00:00
Bob Haarman 3ddeb33e00 [lld] fix data race in ICF.cpp
Summary: Fixes PR36823.

Reviewers: ruiu, pcc, rnk

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44716

llvm-svn: 328610
2018-03-27 06:08:35 +00:00
David Blaikie ddcd856147 Fix for header rename in LLVM
llvm-svn: 328594
2018-03-26 23:43:29 +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 a6fb536e5b [PDB] Make our PDBs look more like MS PDBs.
When investigating bugs in PDB generation, the first step is
often to do the same link with link.exe and then compare PDBs.

But comparing PDBs is hard because two completely different byte
sequences can both be correct, so it hampers the investigation when
you also have to spend time figuring out not just which bytes are
different, but also if the difference is meaningful.

This patch fixes a couple of cases related to string table emission,
hash table emission, and the order in which we emit strings that
makes more of our bytes the same as the bytes generated by MS PDBs.

Differential Revision: https://reviews.llvm.org/D44810

llvm-svn: 328348
2018-03-23 18:43:39 +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
Shoaib Meenai 290f26fefd [COFF] Clarify comment. NFC
Reid pointed out the string table for supporting long section names is a
BFD extension and the comments should reflect that. Explicitly spell out
link.exe's and binutil's behavior around section names and the rationale
for LLD's behavior.

Differential Revision: https://reviews.llvm.org/D42659

llvm-svn: 327736
2018-03-16 20:20:01 +00:00
Peter Collingbourne f1a11f87a0 COFF: Implement string tail merging.
In COFF, duplicate string literals are merged by placing them in a
comdat whose leader symbol name contains a specific prefix followed
by the hash and partial contents of the string literal. This gives
us an easy way to identify sections containing string literals in
the linker: check for leader symbol names with the given prefix.

Any sections that are identified in this way as containing string
literals may be tail merged. We do so using the StringTableBuilder
class, which is also used to tail merge string literals in the ELF
linker. Tail merging is enabled only if ICF is enabled, as this
provides a signal as to whether the user cares about binary size.

Differential Revision: https://reviews.llvm.org/D44504

llvm-svn: 327668
2018-03-15 21:14:02 +00:00
Peter Collingbourne 435b099115 COFF: Move assignment of section RVAs to assignAddresses(). NFCI.
This makes the design a little more similar to the ELF linker and
should allow for features such as ARM range extension thunks to be
implemented more easily.

Differential Revision: https://reviews.llvm.org/D44501

llvm-svn: 327667
2018-03-15 21:13:46 +00:00
Reid Kleckner 8364901f24 [COFF] Enable per-function and data sections in LTO
Summary: This allows post-LTO symbol reordering and ICF.

Reviewers: inglorion

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D44492

llvm-svn: 327563
2018-03-14 20:25:41 +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
Nico Weber f06ae4f3b4 Make lld-link shout at me less.
This makes the output of some flag names in warning messages consistent with
the output of /? and the output of flags in most other diagnostics.

https://reviews.llvm.org/D44307

llvm-svn: 327261
2018-03-12 12:45:40 +00:00
Nico Weber 11a6db3027 [lld-link] For suppressible warnings, print the warning number.
The warning can be suppressed by passing the number to /ignore:.
https://reviews.llvm.org/D44297

llvm-svn: 327257
2018-03-12 12:04:17 +00:00
Nico Weber 0771c604c9 [lld-link] Add support for /ignore:4037.
Fixes PR36657.
https://reviews.llvm.org/D44286

llvm-svn: 327124
2018-03-09 12:41:04 +00:00
Zachary Turner b575f46b6d Resubmit "Write a hash of the executable into the PE timestamp fields."
This fixes the broken tests that were causing failures.  The tests
before were verifying that the time stamp was 0, but now that we
are actually writing a timestamp, I just removed the match against
the timestamp value.

llvm-svn: 327049
2018-03-08 19:33:47 +00:00
Hans Wennborg aee5881a85 [COFF] Make the DOS stub a real DOS program
It only adds a few bytes and is nice for backward compatibility.

Differential Revision: https://reviews.llvm.org/D44018

llvm-svn: 327001
2018-03-08 14:27:28 +00:00
Zachary Turner 0b4af0434b Revert "Write a hash of the executable into the PE timestamp fields."
This is breaking a couple of tests, so I'm reverting temporarily
until I can get everything resolved properly.

llvm-svn: 326943
2018-03-07 21:22:10 +00:00
Zachary Turner 69f3347b56 Write a hash of the executable into the PE timestamp fields.
Windows tools treats the timestamp fields as sort of a build id,
using it to archive executables on a symbol server, as well as
for matching executables to PDBs.  We were writing 0 for these
fields, which would cause symbol servers to break as they are
indexed in the symbol server based on this value.

Although the field is called timestamp, it can really be any
value that is unique per build, so to support reproducible builds
we use a hash of the executable here.

Differential Revision: https://reviews.llvm.org/D43978

llvm-svn: 326920
2018-03-07 18:13:41 +00:00
Rui Ueyama e1847da924 Rename Indent{1,2} -> Indent{8,16}.
llvm-svn: 326912
2018-03-07 17:15:15 +00:00
Rui Ueyama 9e0171fbb6 Do not create temporary strings just to print out spaces. NFC.
llvm-svn: 326841
2018-03-06 22:48:46 +00:00
Rui Ueyama cdd5fb5087 Report an error if you try to link against .dll instead of .lib.
It is a usage error to feed a .dll file instead of a .dll to COFF linker.
Previously, lld failed with a mysterious error message. Now we reject
it at the driver.

Fixes https://bugs.llvm.org/show_bug.cgi?id=36440

Differential Revision: https://reviews.llvm.org/D43964

llvm-svn: 326507
2018-03-01 23:11:30 +00:00
Zachary Turner c6a75a69f1 [PDB] Defer writing the build id until the rest of the PDB is written.
For now this is NFC, but this small refactor opens the door to
letting us embed a hash of the PDB in the build id field of the
PDB.

Differential Revision: https://reviews.llvm.org/D43913

llvm-svn: 326453
2018-03-01 18:00:29 +00:00
Rui Ueyama 67d6908f59 Use DenseMap::lookup() instead of find() and a hand-written null check.
llvm-svn: 326382
2018-02-28 23:03:06 +00:00
Zachary Turner 3868cfd503 Fix use after free in PDB linker.
When merging in types from a type server PDB, we would use a
pointer into the type server PDB's mapped file buffer directly
to avoid copying data.  However, we would close the type server
PDB after we finished merging in its types, which would unmap
all of its memory.  This would lead to a use after free.

We fix this by making a strong reference in the PDBLinker class
to all referenced type server PDBs, thereby making it safe to
hold pointers into its memory mapped contents.

This fixes llvm.org/pr36455

Differential Revision: https://reviews.llvm.org/D43834

llvm-svn: 326345
2018-02-28 18:09:18 +00:00
Rui Ueyama ee17371897 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
2018-02-28 17:38:19 +00:00
Sam Clegg f187c4d2e5 Consistent use of header file for ICF and MarkLive
Previously wasm used a separate header to declare markLive
and ELF used to declare ICF.  This change makes each backend
consistently declare these in their own headers.

Differential Revision: https://reviews.llvm.org/D43529

llvm-svn: 325631
2018-02-20 22:09:59 +00:00
Sam Clegg 3141ddc58d 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
2018-02-20 21:53:18 +00:00
Teresa Johnson 2c2ed3cf03 [lld/LTO] Remove unused Path parameter to AddBufferFn
Summary:
With D43396, no clients use the Path parameter anymore.
This is the lld side fix with D43400.

Depends on D43396 and D43400.

Reviewers: pcc

Subscribers: emaste, inglorion, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D43401

llvm-svn: 325620
2018-02-20 20:21:59 +00:00
Rui Ueyama c6c66225a3 Simplify.
llvm-svn: 325453
2018-02-17 23:37:26 +00:00
Rui Ueyama b3107476a4 Remove an unused accessor and simplify the logic a bit. NFC.
llvm-svn: 325445
2018-02-17 20:41:38 +00:00
Rui Ueyama 03c7f3a2d0 Factor out common code from applySecRel functions.
Differential Revision: https://reviews.llvm.org/D43412

llvm-svn: 325444
2018-02-17 20:28:15 +00:00
Martin Storsjo ef4f78bbf2 [COFF] Add support for ARM64 secrel relocations for add/load instructions
Differential Revision: https://reviews.llvm.org/D43287

llvm-svn: 325396
2018-02-16 22:02:38 +00:00
Rui Ueyama 38781a59f6 Revert r325158: Convert an assert to a static_assert. NFC.
This reverts commit r325158 because it broke GCC builds.

llvm-svn: 325183
2018-02-14 22:43:43 +00:00
Sam Clegg ab31b7759d Convert an assert to a static_assert. NFC.
Differential Revision: https://reviews.llvm.org/D43305

llvm-svn: 325158
2018-02-14 19:28:46 +00:00
Reid Kleckner fd52096259 [LLD] Implement /guard:[no]longjmp
Summary:
This protects calls to longjmp from transferring control to arbitrary
program points. Instead, longjmp calls are limited to the set of
registered setjmp return addresses.

This also implements /guard:nolongjmp to allow users to link in object
files that call setjmp that weren't compiled with /guard:cf. In this
case, the linker will approximate the set of address taken functions,
but it will leave longjmp unprotected.

I used the following program to test, compiling it with different -guard
flags:
  $ cl -c t.c -guard:cf
  $ lld-link t.obj -guard:cf

  #include <setjmp.h>
  #include <stdio.h>
  jmp_buf buf;
  void g() {
    printf("before longjmp\n");
    fflush(stdout);
    longjmp(buf, 1);
  }
  void f() {
    if (setjmp(buf)) {
      printf("setjmp returned non-zero\n");
      return;
    }
    g();
  }
  int main() {
    f();
    printf("hello world\n");
  }

In particular, the program aborts when the code is compiled *without*
-guard:cf and linked with -guard:cf. That indicates that longjmps are
protected.

Reviewers: ruiu, inglorion, amccarth

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43217

llvm-svn: 325047
2018-02-13 20:32:53 +00:00
Rui Ueyama af7242a385 Use reinterpret_cast<> instead of C-style cast. NFC.
It is currently interpreted as reinterpret_cast<>. Make it explicit.

Differential Revision: https://reviews.llvm.org/D43247

llvm-svn: 325033
2018-02-13 18:11:42 +00:00
Sam Clegg 38f52b2eb8 Check that Symbol types are trivially destructible
This adds an extra level of static safety to our use of placement
new to allocate Symbol types.  It prevents the accidental addition
on a non-trivially-destructible member that could allocate and
leak memory.

From the spec: Storage occupied by trivially destructible objects
may be reused without calling the destructor.

Differential Revision: https://reviews.llvm.org/D43244

llvm-svn: 325025
2018-02-13 17:32:31 +00:00
Benjamin Kramer 6400a97418 [COFF] LTO does not require a disassembler.
llvm-svn: 324355
2018-02-06 15:42:41 +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
Colden Cullen b9b6ed9ae6 [LLD][PDB] Implement FIXME: Warn on missing TypeServer PDB rather than error
Summary: Instead of fatal-ing out when missing a type server PDB, insead warn and cache the miss.

Reviewers: rnk, zturner

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42188

llvm-svn: 323893
2018-01-31 17:48:04 +00:00
Martin Storsjo cf47b046f9 [COFF] Remove the temporary file if not updating the import library
Differential Revision: https://reviews.llvm.org/D42621

llvm-svn: 323725
2018-01-30 07:26:01 +00:00
Rui Ueyama b6d3a93594 Warn on nonexistent comdat sections in an /order file.
I didn't implement the feature in the original patch because I didn't
come up with an idea to do that easily and efficiently. Turned out that
that is actually easy to implement.

In this patch, we collect comdat sections before gc is run and warn on
nonexistent symbols in an order file.

Differential Revision: https://reviews.llvm.org/D42658

llvm-svn: 323699
2018-01-29 21:50:53 +00:00
Rui Ueyama d73479ba12 Remove trailing space.
llvm-svn: 323682
2018-01-29 19:55:55 +00:00
Shoaib Meenai 34a1101b06 [COFF] Update comment to reflect link.exe behavior. NFC
In my experimentation with link.exe from both VS 2015 and 2017, it
always produces images with truncated section names. Update the comment
accordingly.

Differential Revision: https://reviews.llvm.org/D42603

llvm-svn: 323598
2018-01-27 18:17:08 +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
Bob Haarman 4ce341ffb6 [COFF] don't replace import library if contents are unchanged
Summary:
This detects when an import library is about to be overwritten with a
newly built one with the same contents, and keeps the old library
instead. The use case for this is to avoid needlessly rebuilding
targets that depend on the import library in build systems that rely
on timestamps to determine whether a target requires rebuilding.

This feature was requested in PR35917.

Reviewers: rnk, ruiu, zturner, pcc

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42326

llvm-svn: 323164
2018-01-23 00:36:42 +00:00
Martin Storsjo 3b611fa93f [COFF] Keep the underscore on exported decorated stdcall functions in MSVC mode
This fixes PR35733.

Differential Revision: https://reviews.llvm.org/D41632

llvm-svn: 323036
2018-01-20 11:44:42 +00:00
Zachary Turner 1bc2ce6b9b Speed up iteration of CodeView record streams.
There's some abstraction overhead in the underlying
mechanisms that were being used, and it was leading to an
abundance of small but not-free copies being made.  This
showed up on a profile.  Eliminating this and going back to
a low-level byte-based implementation speeds up lld with
/DEBUG between 10 and 15%.

Differential Revision: https://reviews.llvm.org/D42148

llvm-svn: 322871
2018-01-18 18:35:01 +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
Rui Ueyama 2c95e798a0 [LLD][COFF] Report error when file will exceed Windows maximum image size (4GB)
Patch by Colden Cullen.

Currently, when a large PE (>4 GiB) is to be produced, a crash occurs
because:

1. Calling setOffset with a number greater than UINT32_MAX causes the
   PointerToRawData to overflow

2. When adding the symbol table to the end of the file, the last section's
   offset was used to calculate file size. Because this had overflowed,
   this number was too low, and the file created would not be large enough.
   This lead to the actual crash I saw, which was a buffer overrun.

This change:

1. Adds comment to setOffset, clarifying that overflow can occur, but it's
   somewhat safe because the error will be handled elsewhere

2. Adds file size check after all output data has been created This matches
   the MS link.exe error, which looks prints as: "LINK : fatal error
   LNK1248: image size (10000EFC9) exceeds maximum allowable size
   (FFFFFFFF)"

3. Changes calculate of the symbol table offset to just use the existing
   FileSize. This should match the previous calculations, but doesn't rely
   on the use of a u32 that can overflow.

4. Removes trivial usage of a magic number that bugged me while I was
   debugging the issue

I'm not sure how to add a test for this outside of adding 4GB of object
files to the repo. If there's an easier way, let me know and I'll be
happy to add a test.

Differential Revision: https://reviews.llvm.org/D42010

llvm-svn: 322605
2018-01-17 01:08:02 +00:00
Pavel Labath a006baa620 Attempt to fix FreeBSD build broken by the previous commit
The compiler could not find the conversion from
unique_ptr<WritableMemoryBuffer> to unique_ptr<MemoryBuffer>. This will
hopefully help it along.

llvm-svn: 322365
2018-01-12 10:09:10 +00:00
Pavel Labath 1c1e24ad96 [lld/COFF] Use WritableMemoryBuffer for creating the manifest
This avoids the need for const_casting the memory buffer contents in
order to write to it.

NFCI.

llvm-svn: 322363
2018-01-12 09:48:41 +00:00
Rui Ueyama 5fa0d6e4a2 [COFF] Process /EXPORT option in fastpath
Patch by Takuto Ikuta.

This patch reduces lld link time of chromium's blink_core.dll in
component build.

Total size of input argument in .directives become nearly 300MB in the
build and almost all its content are /EXPORT.

To reduce time of parsing too many /EXPORT option in the build, I
introduce fastpath for /EXPORT in ArgParser::parseDirectives.

On my desktop machine, 4 times stats of the link time are like below.
Improved around 20%.

This patch
TotalSeconds : 8.6217627
TotalSeconds : 8.5402175
TotalSeconds : 8.6855853
TotalSeconds : 8.3624441
Ave : 8.5525024

master
TotalSeconds : 10.9975031
TotalSeconds : 11.3409428
TotalSeconds : 10.6332897
TotalSeconds : 10.7650687
Ave : 10.934201075

llvm-svn: 322117
2018-01-09 20:36:42 +00:00
Shoaib Meenai 7e3e28f968 [COFF] Delete CanExitEarly
It was being set but never used, and its value is only ever needed
locally in lld::coff::link.

Differential Revision: https://reviews.llvm.org/D41814

llvm-svn: 322026
2018-01-08 21:14:51 +00:00
Shoaib Meenai fd3e4b0ea1 [COFF] Initalize ErrorHandler with CanExitEarly value
Previously, the COFF driver would call exit(1) from the
ErrorHandler in the case of a link error, even if
CanExitEarly=false was specified. Now it initializes
the ErrorHandler in the same way that the ELF driver does.

Patch by Andrew Kelley.

Differential Revision: https://reviews.llvm.org/D41803

llvm-svn: 321983
2018-01-08 05:58:36 +00:00
Zachary Turner 9e52e50ac0 Fix unhandled switch values.
llvm-svn: 321885
2018-01-05 19:28:39 +00:00
Zachary Turner 6047858270 [PDB] Correctly link S_FILESTATIC records.
This is not a record type that clang currently generates,
but it is a record that is encountered in object files generated
by cl.  This record is unusual in that it refers directly to
the string table instead of indirectly to the string table via
the FileChecksums table.  Because of this, it was previously
overlooked and we weren't remapping the string indices at all.
This would lead to crashes in MSVC when trying to display a
variable whose debug info involved an S_FILESTATIC.

Original bug report by Alexander Ganea

Differential Revision: https://reviews.llvm.org/D41718

llvm-svn: 321883
2018-01-05 19:12:40 +00:00
Rui Ueyama a63eed0f80 Do not parse the same /export string more than once.
Differential Revision: https://reviews.llvm.org/D41607

llvm-svn: 321513
2017-12-28 07:41:19 +00:00
Bob Haarman e90ac016e7 [COFF] support /ignore:4217
Summary:
lld-link accepts link.exe's /ignore option, but used to ignore
it. This can lead to semantic differences when warnings are treated as
fatal errors. One such case is when we resolve an __imp_ symbol to a
local definition. We emit a warning in that case, which /wx turns into
a fatal. This change makes lld-link accept /ignore:4217 to suppress
that warning, so that code that links with link.exe /wx /ignore:4217
links with lld-link, too.

Fixes PR35762.

Reviewers: rnk, ruiu

Reviewed By: ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41606

llvm-svn: 321512
2017-12-28 07:02:13 +00:00
Rui Ueyama 130eb04689 [COFF] Do not parse args twice if no rsp files exists
Patch by Takuto Ikuta.

This patch reduces link time of chromium's blink_core.dll in component
build. Total size of input argument in .directives become nearly 300MB
in the build and no rsp file is used. Speedup link by skipping duplicate
parsing.

On my desktop machine, 4 times stats are like below. Improved around 15%.

This patch
TotalSeconds : 18.408538
TotalSeconds : 17.2996744
TotalSeconds : 17.1053862
TotalSeconds : 17.809777
avg: 17.6558439

master
TotalSeconds : 20.9290504
TotalSeconds : 19.9158213
TotalSeconds : 21.0643515
TotalSeconds : 20.8775831
avg: 20.696701575

Differential Revision: https://reviews.llvm.org/D41581

llvm-svn: 321470
2017-12-27 06:08:10 +00:00
Martin Storsjo 6528fb8691 [COFF] Don't set the thumb bit in address table entries for data symbols
The thumb bit should only be set for executable code.

Differential Revision: https://reviews.llvm.org/D41379

llvm-svn: 321149
2017-12-20 06:50:45 +00:00
Shoaib Meenai a1f6fba4d1 [COFF] Clean up debug option handling
/debug and /debug:dwarf are orthogonal. An object file can contain both
CodeView and DWARF debug info, so the combination of /debug:dwarf and
/debug should generate both DWARF and a PDB, rather than /debug:dwarf
always suppressing PDB creation.

/nopdb is now redundant and can be removed. /debug /nopdb was previously
used to support DWARF, but specifying /debug:dwarf is entirely
equivalent to that combination now.

Differential Revision: https://reviews.llvm.org/D41310

llvm-svn: 320896
2017-12-16 00:23:24 +00:00
Shoaib Meenai c4fdbca604 [COFF] Update an outdated comment. NFC
This comment dates from when LLD didn't produce actual PDBs, and is very
outdated now.

llvm-svn: 320894
2017-12-15 23:52:46 +00:00
Shoaib Meenai 111db7945d [COFF] Simplify hasArgs calls. NFC
We can just pass multiple options to hasArgs (which will check for any
of those options being present) instead of calling it multiple times.

llvm-svn: 320892
2017-12-15 23:51:14 +00:00
Martin Storsjo a1e9b6e3d2 [COFF] Set the IMAGE_DLL_CHARACTERISTICS_NO_SEH flag automatically
This seems to match how link.exe sets it.

Differential Revision: https://reviews.llvm.org/D41252

llvm-svn: 320860
2017-12-15 20:53:03 +00:00
Shoaib Meenai d0bd40294d [COFF] Warn for locally imported symbols
Locally imported symbols are a very surprising linker feature. link.exe
warns for them, and we should warn too.

Differential Revision: https://reviews.llvm.org/D41269

llvm-svn: 320792
2017-12-15 07:49:21 +00:00
Sam Clegg ea244bf89b Fix -Wreorder warning
Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D41255

llvm-svn: 320741
2017-12-14 21:09:31 +00:00
Hans Wennborg dcb2f44424 Fix a -Wreorder warning
llvm-svn: 320738
2017-12-14 19:51:18 +00:00
Zachary Turner 0d07a8e948 [COFF] Teach LLD to use the COFF .debug$H section.
This adds the /DEBUG:GHASH option to LLD which will look for
the existence of .debug$H sections in linker inputs and use them
to accelerate type merging.  The clang-cl side has already been
added, so this completes the work necessary to begin experimenting
with this feature.

Differential Revision: https://reviews.llvm.org/D40980

llvm-svn: 320719
2017-12-14 18:07:04 +00:00
Martin Storsjo 94d72b89d6 [COFF] Error out if 20 bit thumb branches are out of range
This is similar to what was added in SVN r277838 for 24 bit
branch instructions.

Differential Revision: https://reviews.llvm.org/D41163

llvm-svn: 320677
2017-12-14 08:56:36 +00:00
Martin Storsjo 9603b8e3f5 [COFF] Sort .pdata for arm64
This works for linking the output from the MSVC compiler.
The pdata entries for arm64 seem to be 8 bytes in the same
(or at least similar) form to arm.

Differential Revision: https://reviews.llvm.org/D41160

llvm-svn: 320676
2017-12-14 08:56:29 +00:00
Martin Storsjo 6ea167cc43 [COFF] Disallow -dynamicbase:no for arm and arm64
This matches what MSVC link.exe does.

Differential Revision: https://reviews.llvm.org/D41051

llvm-svn: 320517
2017-12-12 19:39:13 +00:00
Martin Storsjo 2b964108a0 [COFF] Don't error out on undefined references to __enclave_config
This is required for linking the CRT from MSVC 2017 15.5.

Differential Revision: https://reviews.llvm.org/D41089

llvm-svn: 320462
2017-12-12 08:22:29 +00:00
Rui Ueyama 6074e6b094 Remove redundant local variables.
llvm-svn: 320436
2017-12-11 23:19:11 +00:00
Rui Ueyama b59ceb1068 Do not read the same .lib file more than once.
In the following command line,

  lld-link foo/bar.lib /defaultlib:bar.lib

"/defaultlib:bar.lib" should be a nop even if a file with the same
name exists in other library search path.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35476

Differential Revision: https://reviews.llvm.org/D41094

llvm-svn: 320434
2017-12-11 23:09:18 +00:00
Sam Clegg 0fb6faa0be Prefer `ArrayRef` over `const std::vector&`
Differential Revision: https://reviews.llvm.org/D40993

llvm-svn: 320125
2017-12-08 01:09:21 +00:00
Rui Ueyama c0081639cc Remove checkToString functions and use toString instead.
Differential Revision: https://reviews.llvm.org/D40928

llvm-svn: 320005
2017-12-07 03:24:57 +00:00
Shoaib Meenai 9a5161e056 [COFF] Stop lowercasing paths in messages
It's pretty annoying to have LLD lowercase paths in error messages when
cross-compiling from a case-sensitive filesystem, since e.g. if I want
to examine the problematic object file, I have to perform some manual
case correction instead of just being able to copy the path from the
error message.

Differential Revision: https://reviews.llvm.org/D40931

llvm-svn: 319996
2017-12-07 01:21:27 +00:00
Rui Ueyama bdc5150984 Always evaluate the second argument for CHECK() lazily.
This patch is to rename check CHECK and make it a C macro, so that
we can evaluate the second argument lazily.

Differential Revision: https://reviews.llvm.org/D40915

llvm-svn: 319974
2017-12-06 22:08:17 +00:00
Sam Clegg 7e7566323d toString function take a const refs where possible
Differential Revision: https://reviews.llvm.org/D40824

llvm-svn: 319787
2017-12-05 16:50:46 +00:00
Reid Kleckner 3e89b08303 Revert "Merge .xdata into .rdata by default"
This reverts commit r318699, it is breaking 32-bit SEH handlers in
Chromium.

llvm-svn: 319508
2017-12-01 01:04:31 +00:00
Zachary Turner ca6dbf1440 Split TypeTableBuilder into two classes.
llvm-svn: 319456
2017-11-30 18:39:50 +00:00
Rui Ueyama 215286f2a4 [LLD] [COFF] Support ENTRY and SUBSYSTEM in .drectve sections
Adds support for "/ENTRY" and "/SUBSYSTEM" linker options in .drectve
sections. Some Mozilla binaries were using these directives and MSVC
link.exe appears to allow them. No attempt is made to reconcile these
with the options on the command line.

Patch by David Major!

Differential Revision: https://reviews.llvm.org/D39972

llvm-svn: 319356
2017-11-29 20:46:13 +00:00
Zachary Turner 3e3936da93 Make TypeTableBuilder inherit from TypeCollection.
A couple of places in LLD were passing references to
TypeTableCollections around, which makes it hard to change the
implementation at runtime.  However, these cases only needed to
iterate over the types in the collection, and TypeCollection
already provides a handy abstract interface for this purpose.

By implementing this interface, we can get rid of the need to
pass TypeTableBuilder references around, which should allow us
to swap the implementation at runtime in subsequent patches.

llvm-svn: 319345
2017-11-29 19:35:21 +00:00
Martin Storsjo 0010707e1c [COFF] Don't export symbols that have corresponding __imp_ symbols
GNU ld has got an exception for such symbols, and mingw-w64
occasionally uses that exception to avoid exporting symbols in cases
where they otherwise aren't caught by the other exclusion mechanisms.

Differential Revision: https://reviews.llvm.org/D40553

llvm-svn: 319291
2017-11-29 05:50:49 +00:00
Peter Collingbourne 24ca79c776 COFF: Simplify construction of safe SEH table. NFCI.
Instead of building intermediate sets of exception handlers for each
object file, just create one for the final output file.

Differential Revision: https://reviews.llvm.org/D40581

llvm-svn: 319244
2017-11-28 22:50:53 +00:00
Peter Collingbourne bcf7f290ff COFF: Do not add symbols in discarded sections to SEH handler list.
Differential Revision: https://reviews.llvm.org/D40576

llvm-svn: 319229
2017-11-28 21:30:05 +00:00
Rui Ueyama 2017d52b54 Move Memory.{h,cpp} to Common.
Differential Revision: https://reviews.llvm.org/D40571

llvm-svn: 319221
2017-11-28 20:39:17 +00:00
Martin Storsjo f2508f46ca [COFF] Interpret a period as a separator for section suffix just like '$'
This allows grouping all sections like ".ctors.12345" into ".ctors".

For MinGW, the numerical values for such ctors are all zero-padded,
so a lexical sort is good enough.

Differential Revision: https://reviews.llvm.org/D40408

llvm-svn: 319151
2017-11-28 08:08:37 +00:00
Rui Ueyama 53fe469162 Factor out common code to Common/Strings.cpp.
Differential Revision: https://reviews.llvm.org/D40530

llvm-svn: 319138
2017-11-28 02:15:26 +00:00
Peter Collingbourne 1621c20ffc Reland r319090, "COFF: Do not create SectionChunks for discarded comdat sections." with a fix for debug sections.
If /debug was not specified, readSection will return a null
pointer for debug sections. If the debug section is associative with
another section, we need to make sure that the section returned from
readSection is not a null pointer before adding it as an associative
section.

Differential Revision: https://reviews.llvm.org/D40533

llvm-svn: 319133
2017-11-28 01:30:07 +00:00
Sam Clegg a80d94d52b Rename `Symtab` private memory to avoid confusion with global `Symtab`
This is also consistent with SymVector that exists in COFF port
and soon to be added to the wasm port.

Split off as part of https://reviews.llvm.org/D40371

Differential Revision: https://reviews.llvm.org/D40525

llvm-svn: 319113
2017-11-27 23:16:06 +00:00
Sam Clegg e2ed092e01 Consistent use of <internal> when displaying internal symbol names
Differential Revision: https://reviews.llvm.org/D40510

llvm-svn: 319108
2017-11-27 22:49:16 +00:00
Peter Collingbourne c8477b8234 Revert r319090, "COFF: Do not create SectionChunks for discarded comdat sections."
Caused test failures in check-cfi on Windows.
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/20284

llvm-svn: 319100
2017-11-27 21:37:51 +00:00
Peter Collingbourne 3f2921f5ec COFF: Do not create SectionChunks for discarded comdat sections.
With this change, instead of creating a SectionChunk for each section
in the object file, we only create them when we encounter a prevailing
comdat section.

Also change how symbol resolution occurs between comdat symbols. Now
only the comdat leader participates in comdat resolution, and not any
other external associated symbols. This is more in line with how COFF
semantics are defined, and should allow for a more straightforward
implementation of non-ANY comdat types.

On my machine, this change reduces our runtime linking a release
build of chrome_child.dll with /nopdb from 5.65s to 4.54s (median of
50 runs).

Differential Revision: https://reviews.llvm.org/D40238

llvm-svn: 319090
2017-11-27 20:42:34 +00:00
Rui Ueyama 66384b391e Return early. NFC.
llvm-svn: 318826
2017-11-22 09:06:42 +00:00
Rui Ueyama c121401ca5 Add more blank lines to separate code chunks.
llvm-svn: 318825
2017-11-22 09:06:27 +00:00
Peter Collingbourne f874bd67d8 COFF: Emit a COFF symbol table if /debug:dwarf is specified.
This effectively reverts r318548 and r318635 while keeping the
functionality behind the flag and preserving the bug fix from r318548.

Differential Revision: https://reviews.llvm.org/D40264

llvm-svn: 318721
2017-11-21 01:14:14 +00:00
Reid Kleckner 95cc796cf1 Merge .xdata into .rdata by default
Summary: MSVC does this. The user can override it with their own /merge: flag.

Reviewers: ruiu, pcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40197

llvm-svn: 318699
2017-11-20 21:49:35 +00:00
Peter Collingbourne 31275d4472 COFF: Correctly handle relocations against early discarded sections.
Don't crash if we encounter a reference to an early discarded section
(such as .drectve). Instead, handle them the same way as sections
discarded by comdat merging, i.e. either print an error message or
(for debug sections) silently ignore the relocation.

Differential Revision: https://reviews.llvm.org/D40235

llvm-svn: 318689
2017-11-20 19:37:07 +00:00
Peter Collingbourne 80f961ab66 COFF: Remove the SymbolBodies vector, and rename SparseSymbolBodies to Symbols.
Differential Revision: https://reviews.llvm.org/D40237

llvm-svn: 318683
2017-11-20 18:52:53 +00:00
Peter Collingbourne d01571353d COFF: Stop requiring comdat sections to have an external leader to participate in ICF.
This requirement was added in r254578 to fix pr25686. However, it
appears to have originated from a misdiagnosis of the problem: link.exe
refused to merge the two sections because they are non-executable,
not because they have internal leaders. If I set up a similar scenario
with functions instead of globals I see that link.exe merges them.

Differential Revision: https://reviews.llvm.org/D40236

llvm-svn: 318682
2017-11-20 18:51:29 +00:00
Peter Collingbourne 5c7b467b6e COFF: Change SparseChunks to be of type std::vector<SectionChunk *>. NFC.
llvm-svn: 318636
2017-11-20 05:31:23 +00:00
Peter Collingbourne 38e3a1ea17 COFF: Remove unused fields. NFC.
llvm-svn: 318635
2017-11-20 05:31:09 +00:00
Peter Collingbourne 5e80bdebd2 COFF: Stop emitting a non-standard COFF symbol table into PEs.
Now that our support for PDB emission is reasonably good, there is
no longer a need to emit a COFF symbol table.

Also fix a bug where we would fail to emit a string table for long
section names if /debug was not specified.

Differential Revision: https://reviews.llvm.org/D40189

llvm-svn: 318548
2017-11-17 19:51:20 +00:00
Reid Kleckner d99ac29a24 All .xdata sections are eligble for ICF
Summary:
Many small functions have identical unwind info because they push the
same sets of CSRs in the same order and have the same stack and prologue
size. The VC linker merges duplicate .xdata, and so should LLD.

This reduces the .xdata section size of clang.exe from 1.8MB to 94KB.

Reviewers: pcc, ruiu

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40160

llvm-svn: 318547
2017-11-17 19:50:10 +00:00