Commit Graph

414 Commits

Author SHA1 Message Date
Rui Ueyama 4bce7bcc88 COFF: Output messages for /verbose to stdout instead of stderr.
This patch also makes the message less verbose.

llvm-svn: 247853
2015-09-16 21:30:40 +00:00
Rui Ueyama b02a320f5e COFF: Enable ICF by default.
MSVC linker enables ICF as long as /opt:ref is eanbled, so do we.

llvm-svn: 247817
2015-09-16 16:41:38 +00:00
Rui Ueyama c04d5dbf20 COFF: Rename /opt:lldicf -> /opt:icf.
Now that ICF is complete, we can rename this option so that
the driver accepts the MSVC-compatible command line option.

llvm-svn: 247816
2015-09-16 16:33:57 +00:00
Rui Ueyama 92298d5418 COFF: Create ICF class to move code from SectionChunk to ICF. NFC.
This patch defines ICF class and defines ICF-related functions as
members of the class. By doing this we can move code that are
related only to ICF from SectionChunk to the newly-defined class.
This also eliminates a global variable "NextID".

llvm-svn: 247802
2015-09-16 14:19:10 +00:00
Rui Ueyama 9cb2870ce0 ICF: Improve ICF to reduce more sections than before.
This is a patch to make LLD to be on par with MSVC in terms of ICF
effectiveness. MSVC produces a 27.14MB executable when linking LLD.
LLD previously produced a 27.61MB when self-linking. Now the size
is reduced to 27.11MB. Note that without ICF the size is 29.63MB.

In r247387, I implemented an algorithm that handles section graphs
as cyclic graphs and merge them using SCC. The algorithm did not
always work as intended as I demonstrated in r247721. The new
algortihm implemented in this patch is different from the previous
one. If you are interested the details, you want to read the file
comment of ICF.cpp.

llvm-svn: 247770
2015-09-16 03:26:31 +00:00
Duncan P. N. Exon Smith a11f81973a LTO: Adjust to LLVM r247735
Perhaps lld wants to disable the verifier sometimes during COFF LTO, but
for now just match behaviour from before r247735.

llvm-svn: 247736
2015-09-15 23:06:16 +00:00
Rui Ueyama c48f78ca5a Fix typo.
llvm-svn: 247645
2015-09-15 00:35:41 +00:00
Rui Ueyama 13563d8645 Fix style.
llvm-svn: 247644
2015-09-15 00:33:11 +00:00
Rui Ueyama 8e186df2f5 COFF: Corrected error message if a section failed to load.
There is no sense to use Name in these lines as it is not initialized yet.

Patch from Igor Kudrin!

llvm-svn: 247531
2015-09-13 20:22:22 +00:00
Rui Ueyama 5b93aa51de COFF: Teach ICF to merge cyclic graphs.
Previously, LLD's ICF couldn't merge cyclic graphs. That was unfortunate
because, in COFF, cyclic graphs are not exceptional at all. That is
pretty common.

In this patch, sections are grouped by Tarjan's strongly connected
component algorithm to get acyclic graphs. And then we try to merge
SCCs whose outdegree is zero, and remove them from the graph. This
makes other SCCs to have outdegree zero, so we can repeat the
process until all SCCs are removed. When comparing two SCCs, we handle
cycles properly.

This algorithm works better than previous one. Previously, self-linking
produced a 29.0MB executable. It now produces a 27.7MB. There's still some
gap compared to MSVC linker which produces a 27.1MB executable for the
same input. So the gap is narrowed, but still LLD is not on par with MSVC.
I'll investigate that later.

llvm-svn: 247387
2015-09-11 04:29:03 +00:00
Rui Ueyama 3c28ba38de COFF: Split doICF(). No functionality change.
llvm-svn: 246934
2015-09-05 23:06:32 +00:00
Rui Ueyama ef907ec82d COFF: Implement a better algorithm for ICF.
Identical COMDAT Folding is a feature to merge COMDAT sections
by contents. Two sections are considered the same if their contents,
relocations, attributes, etc, are all the same.

An interesting fact is that MSVC linker takes "iterations" parameter
for ICF because the algorithm they are using is iterative. Merging
two sections could make more sections to be mergeable because
different relocations could now point to the same section. ICF is
repeated until we get a convergence (until no section can be merged).
This algorithm is not fast. Usually it needs three iterations until a
convergence is obtained.

In the new algorithm implemented in this patch, we consider sections
and relocations as a directed acyclic graph, and we try to merge
sections whose outdegree is zero. Sections with outdegree zero are then
removed from the graph, which makes  other sections to have outdegree
zero. We repeat that until all sections are processed. In this
algorithm, we don't iterate over the same sections many times.

There's an apparent issue in the algorithm -- the section graph is
not guaranteed to be acyclic. It's actually pretty often cyclic.
So this algorithm cannot eliminate all possible duplicates.
That's OK for now because the previous algorithm was not able to
eliminate cycles too. I'll address the issue in a follow-up patch.

llvm-svn: 246878
2015-09-04 21:35:54 +00:00
Rui Ueyama 434de7a33f Remove unused variable.
llvm-svn: 246874
2015-09-04 21:05:30 +00:00
Rui Ueyama 2dcc23580e COFF: Use section content checksum for ICF.
Previously, we calculated our own hash values for section contents.
Of coruse that's slow because we had to access all bytes in sections.
Fortunately, COFF objects usually contain hash values for COMDAT
sections. We can use that to speed up Identical COMDAT Folding.

llvm-svn: 246869
2015-09-04 20:45:50 +00:00
Rui Ueyama 31e66e32b4 COFF: Ignore /GUARDSYM option.
The option is added in MSVC 2015, and there's no documentation about
what the option is. This patch is to ignore the option for now, so that
at least LLD is usable with MSVC 2015.

llvm-svn: 246780
2015-09-03 16:20:47 +00:00
Rui Ueyama 6295b27184 COFF: /delayload:<DLLNAME> is case-insensitive.
llvm-svn: 246770
2015-09-03 14:49:47 +00:00
Rafael Espindola fb497d79f6 Remove an allocator which was used for just one allocation.
llvm-svn: 246662
2015-09-02 16:07:11 +00:00
Rui Ueyama bfbd277a1c COFF: Preserve original spelling of DLL file name.
This patch fixes a subtle incompatibility with MSVC linker.
MSVC linker preserves the original spelling of a DLL in the
import descriptor table. LLD previously converted all
characters to lowercase. Usually this difference is benign,
but if a program explicitly checks for DLL file names, the
program could fail.

llvm-svn: 246620
2015-09-02 07:27:31 +00:00
Davide Italiano 491d3bfd43 [COFF] Remove dead private field. Also fixes build with -Werror.
llvm-svn: 246553
2015-09-01 16:05:53 +00:00
Rui Ueyama 100ffacf2c COFF: .exe files should be able to export functions.
In r246424, I made a change that disables non-DLL to export
symbols. It turned out that the change was not correct. Both
DLLs and executables are able to export symbols (although the
latter is relatively rare). This change restores the feature.

llvm-svn: 246537
2015-09-01 09:15:58 +00:00
Rui Ueyama dfff2542b8 COFF: Make import libraries compatible with MSVC link.
I have totally no idea why, but MSVC linker is sensitive about
file names of archive members. If we do not make import library
file names to the same as the DLL name, MSVC link *crashes*
when it is processing the library file. This patch is to set
the same name.

llvm-svn: 246535
2015-09-01 08:08:57 +00:00
Rui Ueyama 84f9218417 COFF: Set "Data" bit for data symbols in the import descriptor.
llvm-svn: 246533
2015-09-01 06:46:10 +00:00
Rui Ueyama f10a32014d COFF: Improve dllexported name mangling compatibility.
The rules for dllexported symbols are overly complicated due to
x86 name decoration, fuzzy symbol resolution, and the fact that
one symbol can be resolved by so many different names. The rules
are probably intended to be "intuitive", so that users don't have
to understand the name mangling schemes, but it seems that it can
lead to unintended symbol exports.

To make it clear what I'm trying to do with this patch, let me
write how the export rules are subtle and complicated.

 - x86 name decoration: If machine type is i386 and export name
   is given by a command line option, like /export:foo, the
   real symbol name the linker has to search for is _foo because
   all symbols are decorated with "_" prefixes. This doesn't happen
   on non-x86 machines. This automatic name decoration happens only
   when the name is not C++ mangled.

   However, the symbol name exported from DLLs are ones without "_"
   on all platforms.

   Moreover, if the option is given via .drectve section, no
   symbol decoration is done (the reason being that the .drectve
   section is created by a compiler and the compiler should always
   know the exact name of the symbol, I guess).

 - Fuzzy symbol resolution: In addition to x86 name decoration,
   the linker has to look for cdecl or C++ mangled symbols
   for a given /export. For example, it searches for not only
   _foo but also _foo@<number> or ??foo@... for /export:foo.

Previous implementation didn't get it right. I'm trying to make
it as compatible with MSVC linker as possible with this patch
however the rules are. The new code looks a bit messy to me, but
I don't think it can be simpler due to the ad-hoc-ness of the rules.

llvm-svn: 246424
2015-08-31 08:43:21 +00:00
Peter Collingbourne df5783b7a5 COFF: Implement parallel LTO code generation.
This is exposed via a new flag /opt:lldltojobs=N, where N is the number of
code generation threads.

Differential Revision: http://reviews.llvm.org/D12309

llvm-svn: 246342
2015-08-28 22:16:09 +00:00
Rui Ueyama 40f4d86f5f COFF: Create short import files instead of using lib.exe.
lib.exe has a feature to create import library files (which contain
short import files) from module-definition files. Previously, we were
using that feature, but it turned out that the feature is not complete
for us.

There seems no way to specify "Import Types" in module-definition file.
lib.exe always adds "_" to given symbols and specify IMPORT_NAME_UNDECORATE.
We need more fine-grainded control on that value.

This patch teaches LLD to create short import files itself.
We are still using lib.exe, but the use of the tool is limited to create
empty import library files. We then create short import files and add them
to the empty files as new members.

This patch does not intend to change the functionality. LLD produces
the same import libraries as before. I'll make another change to create
different import libraries in a follow-up patch.

llvm-svn: 246292
2015-08-28 10:52:05 +00:00
Rui Ueyama c0c74e1b8a COFF: Print out module-definition files if /verbose is given.
This is useful for testing.

llvm-svn: 246032
2015-08-26 12:37:54 +00:00
Rui Ueyama 2caf407107 COFF: Show real command line options if /verbose is given.
llvm-svn: 246023
2015-08-26 07:12:08 +00:00
Peter Collingbourne 0bb50d92b6 COFF: Update for LTO API change.
llvm-svn: 245892
2015-08-24 22:22:58 +00:00
Rui Ueyama 6a883b086e COFF: Improve debug helper function.
SectionChunk::getDebugName crashed if the symbol was a nullptr.

llvm-svn: 245677
2015-08-21 07:01:10 +00:00
Rui Ueyama d2d2360222 COFF: Fix /lldmap option.
isLive returns false if it's not COMDAT, so check for that condition.

llvm-svn: 245676
2015-08-21 07:01:08 +00:00
Rui Ueyama 04ec69aa9e COFF: Use ErrorOr::operator* instead of ErrorOr::get.
This patch is to make COFF coding style consistent with ELF. NFC.

llvm-svn: 245282
2015-08-18 09:18:15 +00:00
Rui Ueyama 570752c7ac Do not use unique pointers. NFC.
These unique pointers have the exact same lifetime as automatic
variables, so use automatic variables instead.

llvm-svn: 245281
2015-08-18 09:13:25 +00:00
Rui Ueyama 95b781d863 COFF: Do not handle __NULL_IMPORT_DESCRIPTOR differently than the other symbols.
__NULL_IMPORT_DESCRIPTOR is a symbol used by MSVC liner to construct
the import descriptor table. We do not use the symbol. Previously,
we had code to skip that symbol. That code does not actually do
anything meaningful because no one is referencing the symbol, the
symbol would naturally be ignored. This patch stops recognizing
the symbol.

llvm-svn: 245280
2015-08-18 09:06:41 +00:00
Rui Ueyama 7171c82194 COFF: Allow forward reference for weak externals
Previously, weak external symbols could reference only symbols that
appeared before them. Although that covers almost all use cases
of weak externals, there are object files out there which contains
weak externals that have forward references.

This patch supports such weak externals.

llvm-svn: 245258
2015-08-17 23:35:43 +00:00
Rui Ueyama d157088adb COFF: Fix the order of the DLL import entry.
There are some DLLs whose initializers depends on other DLLs'
initializers. The initialization order matters for them.

MSVC linker uses the order of the libraries from the command line.
LLD used ASCII-betical order. So they were incompatible.
This patch makes LLD compatible with MSVC.

llvm-svn: 245201
2015-08-17 08:30:31 +00:00
Rui Ueyama e73e418bb4 COFF: Simplify Writer::createImportTables.
A short import library has up to two symbols, so we don't have
to do a for-loop and type dispatch in createImportTables.

llvm-svn: 245200
2015-08-17 07:27:45 +00:00
Rafael Espindola beee25e484 Make these headers as being c++.
llvm-svn: 245050
2015-08-14 14:12:54 +00:00
Peter Collingbourne 526ff15546 COFF: Introduce flag /opt:lldlto=N for controlling LTO optimization level.
Differential Revision: http://reviews.llvm.org/D12024

llvm-svn: 245027
2015-08-14 04:47:07 +00:00
Rafael Espindola 5c546a1437 COFF: In chunks, store the offset from the start of the output section. NFC.
This is more convenient than the offset from the start of the file as we
don't have to worry about it changing when we move the output section.

This is a port of r245008 from ELF.

llvm-svn: 245018
2015-08-14 03:30:59 +00:00
Rafael Espindola f0461ba985 Update for llvm api change.
llvm-svn: 244856
2015-08-13 01:07:08 +00:00
Rafael Espindola bdc8f2fb83 Update for llvm api change.
llvm-svn: 244849
2015-08-13 00:31:46 +00:00
Rui Ueyama fa071e13aa COFF: Align sections to 512-byte boundaries on disk.
Sections must start at page boundaries in memory, but they
can be aligned to sector boundaries (512-bytes) on disk.
We aligned them to 4096-byte boundaries even on disk, so we
wasted disk space a bit.

llvm-svn: 244691
2015-08-11 23:09:00 +00:00
Rui Ueyama 3c4737db54 COFF: Ignore /editandcontinue option.
llvm-svn: 244626
2015-08-11 16:46:08 +00:00
Rui Ueyama bc9891f01d COFF: Update README.
It's no longer "new" because the old COFF linker has been removed.
Update the introduction accordingly.

llvm-svn: 244565
2015-08-11 03:44:51 +00:00
Rui Ueyama 857b30356f Move file-local classes to an anonymous namespace. NFC.
llvm-svn: 244525
2015-08-10 23:02:57 +00:00
Rui Ueyama 107db55ac4 COFF: Define symbols for MSVC 2015 Control Flow Protection.
MSVC 2015's load configuration object (__load_config_used) contains
references to these symbols. I don't fully understand how it works,
but looks like these symbols are linker-defined ones. So I define them
here in the Driver. With this patch, LLD can self-host with MSVC 2015.

This patch is to link MSVC 2015-produced object files. It does not
implement Control Flow Protection. If I understand correctly, the
linker has to create a bitmap of function entry point addresses for
the CFG runtime. We don't do that yet. Produced executables will not
be protected by CFG.

llvm-svn: 244425
2015-08-09 21:01:06 +00:00
Rui Ueyama 27e470abae COFF: Do not fall through if /lib is processed.
llvm-svn: 244424
2015-08-09 20:45:17 +00:00
Rui Ueyama 234afc4a0e Remove unused `using`.
llvm-svn: 244422
2015-08-09 20:38:58 +00:00
Rui Ueyama 611add25e3 COFF: Simplify.
SymbolTable::find(mangle(X)) is equivalent to SymbolTable::findUnderscore(X)
except that the latter is slightly efficient as that doesn't allocate a new
string.

llvm-svn: 244377
2015-08-08 00:23:37 +00:00
Rui Ueyama 8ebdc8cedc COFF: Handle _load_config_used in the same way as other special symbols.
Handling the symbol this way is consistent with other symbols, such as
_tls_used. NFC.

llvm-svn: 244367
2015-08-07 22:43:53 +00:00
Rui Ueyama 237c8ff796 Remove unused variable.
llvm-svn: 244365
2015-08-07 22:40:13 +00:00
Rui Ueyama 1574b8ecfb COFF: Update a comment.
llvm-svn: 244258
2015-08-06 19:57:21 +00:00
Rafael Espindola b835ae8e4a Port the error functions from ELF to COFF.
This has a few advantages

* Less C++ code (about 300 lines less).
* Less machine code (about 14 KB of text on a linux x86_64 build).
* It is more debugger friendly. Just set a breakpoint on the exit function and
  you get the complete lld stack trace of when the error was found.
* It is a more robust API. The errors are handled early and we don't get a
  std::error_code hot potato being passed around.
* In most cases the error function in a better position to print diagnostics
  (it has more context).

llvm-svn: 244215
2015-08-06 14:58:50 +00:00
Rui Ueyama 9b000812a4 COFF: ARM: Sort .pdata section correctly.
On ARM, exception handler entries in .pdata section are 8 byte long.

llvm-svn: 244191
2015-08-06 03:45:27 +00:00
Rui Ueyama cb8474edae COFF, ELF2: Pass output file path implicitly using Config global variable.
Various parameters are passed implicitly using Config global variable
already. Output file path is no different from others, so there was no
special reason to handle that differnetly.

This patch changes the signature of writeResult(SymbolTable *, StringRef)
to writeResult(SymbolTable *).

llvm-svn: 244180
2015-08-05 23:51:50 +00:00
Rui Ueyama 685c41cd39 COFF: Simplify Writer interface by hiding Writer class.
llvm-svn: 244175
2015-08-05 23:43:53 +00:00
Rafael Espindola 4280a96468 Handle writeImportLibrary failing.
We were printing an error but exiting with 0.

Not sure how to test this. We could add a no-winlib feature,
but that is probably not worth it.

llvm-svn: 244109
2015-08-05 20:03:57 +00:00
Rui Ueyama 67fcd1a0c7 COFF: Fix bad #includes.
Writer.h is intended to be included only by Writer.cpp and Driver.cpp.
Use of the header in other files are bad.

llvm-svn: 244106
2015-08-05 19:51:28 +00:00
Rui Ueyama ba7c041f21 COFF: ARM: Implepment BLX23T relocation and fix Branch20T.
I fed the same test to MSVC linker and got the same output,
so I believe this implementation is correct.

llvm-svn: 244102
2015-08-05 19:40:07 +00:00
Rui Ueyama 18edc83b6c COFF: Fix error message. Space was missing.
llvm-svn: 243794
2015-07-31 21:51:25 +00:00
Reid Kleckner 981576daf7 Add some help strings for /dll and /debug so they show up in /?
llvm-svn: 243757
2015-07-31 16:40:38 +00:00
Peter Collingbourne e7107ec03b COFF: When resolving _load_config_used, add it as a GC root.
This fixes the cases where the symbol is defined in a comdat or by bitcode.

Differential Revision: http://reviews.llvm.org/D11673

llvm-svn: 243735
2015-07-31 05:33:34 +00:00
Rui Ueyama 7b276e2fb4 COFF: Move code for Identical COMDAT Folding to ICF.cpp.
llvm-svn: 243701
2015-07-30 22:57:21 +00:00
Rui Ueyama f69ecc1212 COFF: Handle all COMDAT sections as non-GC root.
I don't remember why I thought that only functions are subject
of garbage collection, but the comment here said so, which is
not correct. Moreover, the code just below the comment does not
do what the comment says -- it handles non-COMDAT, non-function
sections as GC root. As a result, it just handles non-COMDAT
sections as GC root.

This patch cleans that up by removing SectionChunk::isRoot and
use isCOMDAT instead.

llvm-svn: 243700
2015-07-30 22:48:45 +00:00
David Majnemer 13ac40ea6e COFF: Sort output sections which start with .debug to the end of the file
We want to convince the NT loader not to map these sections into memory.
A good first step is to move them to the end of the executable.

Differential Revision: http://reviews.llvm.org/D11655

llvm-svn: 243680
2015-07-30 20:26:55 +00:00
Rui Ueyama e0d68e381b Remove unused #includes.
llvm-svn: 243588
2015-07-29 22:53:29 +00:00
Rui Ueyama 966acb2e2f COFF: Suppress "Duplicate entry" warning of lib.exe
We create a module-definition file and give that to lib.exe to
create an import library file. A module-definition has to be
syntactically and semantically correct, of course.

There was a case that we created a module-definition file that
lib.exe would complain for duplicate entries. If a user gives
an unmangled and mangled name for the same symbol, we would end
up having two duplicate lines for the mangled name in a module-
definition file.

This patch fixes that issue by uniquefying entries by mangled
symbol name.

llvm-svn: 243587
2015-07-29 22:38:27 +00:00
Rui Ueyama 4323831732 COFF: Fix command line option spelling.
llvm-svn: 243573
2015-07-29 21:01:15 +00:00
Rui Ueyama 46682630f4 COFF: Ignore /ThrowNew command line option.
This command line option is added since MSVC 2015. Our wild guess is
that the flag is for LTCG and we can safely ignore that.

llvm-svn: 243568
2015-07-29 20:29:15 +00:00
Rui Ueyama ff88d5a26f COFF: Add /safeseh command line option.
If /safeseh is specified, all input files must be compatible with Safe SEH.

llvm-svn: 243565
2015-07-29 20:25:40 +00:00
Rui Ueyama 8bc43a142b COFF: ARM: Fix relocations to thumb code.
Windows ARM is the thumb ARM environment, and pointers to thumb code
needs to have its LSB set. When we apply relocations, we need to
adjust the LSB if it points to an executable section.

llvm-svn: 243560
2015-07-29 19:25:00 +00:00
Rui Ueyama 56965f4b32 COFF: ARM: Fix DLL import table.
The previous test was testing -flavor link. This patch correctly
tests link2 and fixes a bug that we didn't emit import thunks.

llvm-svn: 243559
2015-07-29 19:24:58 +00:00
Rui Ueyama eb26e1d03c COFF: Fix SECREL and SECTION relocations.
SECREL should sets the 32-bit offset of the target from the beginning
of *target's* output section. Previously, the offset from the beginning
of source's output section was used instead.

SECTION means the target section's index, and not the source section's
index. This patch fixes that issue too.

llvm-svn: 243535
2015-07-29 16:30:45 +00:00
Rui Ueyama ca577fd536 COFF: Remove unused command line option.
llvm-svn: 243533
2015-07-29 16:30:34 +00:00
Rui Ueyama 29f74c312a COFF: Set load config table entry on non-x86.
llvm-svn: 243532
2015-07-29 16:30:31 +00:00
Rui Ueyama 506f6d1ae1 COFF: _tls_used is __tls_used on x86.
llvm-svn: 243495
2015-07-28 22:56:02 +00:00
Rui Ueyama 9420dee328 COFF: Fix export symbol names for x86.
I don't fully understand the rationale behind the name mangling
scheme used for the DLL export table and the import library.
Why only leading "_" is dropped for the import library while
both "_" and "@" are dropped from DLL symbol table? But this seems
to be what MSVC linker does.

llvm-svn: 243490
2015-07-28 22:34:24 +00:00
Rui Ueyama 635e85a647 COFF: Update README to mention that it now supports 32-bit x86.
The linker is now able to link not only LLVM/Clang/LLD for x86 but
even larger programs. I confirmed that it successsfully linked Chrome
for x86. Because the browser is a pretty large program, I think I can
say that the linker is now mostly feature complete. (I'm pretty sure
that there are hidden bugs somewhere, but they shouldn't be significant.)

llvm-svn: 243377
2015-07-28 03:40:58 +00:00
Rui Ueyama cfb874a3d4 COFF: Do not ignore /merge if /debug is specified.
Previously, we ignore /merge option if /debug is specified
because I thought that was MSVC linker did. This was wrong.
/merge shouldn't be ignored even in debug mode.

llvm-svn: 243375
2015-07-28 03:24:23 +00:00
Rui Ueyama d68e211be5 COFF: /HighEntropyVA is on by default only on 64-bit.
llvm-svn: 243374
2015-07-28 03:15:57 +00:00
Rui Ueyama 4d54534627 COFF: Add /LargeAddressAware command line option.
llvm-svn: 243373
2015-07-28 03:12:00 +00:00
Rui Ueyama 7e387a68de COFF: Fix 32-bit delay-import address table.
The address table entry is 32-bit wide on 32-bit and 64-bit on 64-bit.
Previously, it was 64-bit even on 32-bit.

llvm-svn: 243372
2015-07-28 02:54:18 +00:00
Rui Ueyama 2832ce95a5 COFF: Skip non-DWARF debug info sections.
Leaving them in an executable is basically harmless but wastes disk space.
Because no one is using non-DWARF debug info linked by LLD, we can just
remove them.

llvm-svn: 243364
2015-07-28 01:06:58 +00:00
Rui Ueyama e44524de65 Use SmallDenseMap instead of std::map where we don't care about order of keys.
llvm-svn: 243358
2015-07-28 00:17:25 +00:00
Rui Ueyama a8eed749a2 COFF: Write import library symbols to a symbol table.
Previously no __imp_ symbols nor dllimport thunk functions were
written to a symbol table.

llvm-svn: 243350
2015-07-27 23:40:20 +00:00
Rui Ueyama 5e706b3ee3 COFF: Use short identifiers. NFC.
llvm-svn: 243229
2015-07-25 21:54:50 +00:00
Rui Ueyama 5c437cd1e9 COFF: Fix image base address for 32-bit.
0x140000000 or 0x180000000 are not correct image base addresses
for 32-bit. They are actually much smaller.

llvm-svn: 243228
2015-07-25 21:42:33 +00:00
Rui Ueyama 3dd9372d2b COFF: ARM: Support import functions.
llvm-svn: 243205
2015-07-25 03:39:29 +00:00
Rui Ueyama cde7a7907e COFF: ARM: Implement BLX23T relocation.
llvm-svn: 243204
2015-07-25 03:25:28 +00:00
Rui Ueyama 3d9c8639c3 COFF: ARM: Implement BRANCH24T relocation.
llvm-svn: 243202
2015-07-25 03:19:34 +00:00
Rui Ueyama 237fca1451 COFF: ARM: Implement MOV32T relocation.
llvm-svn: 243201
2015-07-25 03:03:46 +00:00
Rui Ueyama a265b01353 COFF: ARM: Set correct entry point address.
llvm-svn: 243199
2015-07-25 02:25:14 +00:00
Rui Ueyama 3afd5bfd7b COFF: Handle base relocation as a tuple of relocation type and RVA. NFC.
On x64 and x86, we use only one base relocation type, so we handled
base relocations just as a list of RVAs. That doesn't work well for
ARM becuase we have to handle two types of base relocations on ARM.
This patch changes the type of base relocation from uint32_t to
{reltype, uint32_t} to make it easy to port this code to ARM.

llvm-svn: 243197
2015-07-25 01:44:32 +00:00
Rui Ueyama 28df04211c COFF: Split ImportThunkChunk into x86 and x64. NFC.
This change should make it easy to port this code to ARM.

llvm-svn: 243195
2015-07-25 01:16:06 +00:00
Rui Ueyama 1c341a54de COFF: Do not align import thunks on 16-byte boundaries on x86.
Looks like MSVC linker aligns them only on x64.

llvm-svn: 243194
2015-07-25 01:16:04 +00:00
Rui Ueyama 35ccb0f7d4 COFF: Don't assume !is64() means i386.
In many places we assumed that is64() means AMD64 and i386 otherwise.
This assumption is not sound because Windows also supports ARM.
The linker doesn't support ARM yet, but this is a first step.

llvm-svn: 243188
2015-07-25 00:20:06 +00:00
Rui Ueyama cd3f99b6c5 COFF: Implement Safe SEH support for x86.
An object file compatible with Safe SEH contains a .sxdata section.
The section contains a list of symbol table indices, each of which
is an exception handler function. A safe SEH-enabled executable
contains a list of exception handler RVAs. So, what the linker has
to do to support Safe SEH is basically to read the .sxdata section,
interpret the contents as a list of symbol indices, unique-fy and
sort their RVAs, and then emit that list to .rdata. This patch
implements that feature.

llvm-svn: 243182
2015-07-24 23:51:14 +00:00
Rui Ueyama 2296dc137c COFF: Fix base relocation type for x86.
llvm-svn: 243178
2015-07-24 23:24:45 +00:00
Rui Ueyama 3cb895c930 COFF: Fix __ImageBase symbol relocation.
__ImageBase is a special symbol whose value is the image base address.
Previously, we handled __ImageBase symbol as an absolute symbol.

Absolute symbols point to specific locations in memory and the locations
never change even if an image is base-relocated. That means that we
don't have base relocation entries for absolute symbols.

This is not a case for __ImageBase. If an image is base-relocated, its
base address changes, and __ImageBase needs to be shifted as well.
So we have to have base relocations for __ImageBase. That means that
__ImageBase is not really an absolute symbol but a different kind of
symbol.

In this patch, I introduced a new type of symbol -- DefinedRelative.
DefinedRelative is similar to DefinedAbsolute, but it has not a VA but RVA
and is a subject of base relocation. Currently only __ImageBase is of
the new symbol type.

llvm-svn: 243176
2015-07-24 22:58:44 +00:00
Rui Ueyama afad42f9ea COFF: Set Load Configuration entry in Data Directory.
Load Configuration field points to a structure containing information
for SEH. That data strucutre is not created by the linker but provided
by an external file. What we have to do is just to set __load_config_used
address to the header.

llvm-svn: 242427
2015-07-16 18:30:35 +00:00