Commit Graph

272 Commits

Author SHA1 Message Date
Rui Ueyama cf0dd1ebf2 Move utility functions to DriverUtils.cpp.
llvm-svn: 267602
2016-04-26 20:41:32 +00:00
Rui Ueyama 673b609586 Handle Windows drive letters and ".." for --reproduce.
When --reproduce <path> is given, then we need to concatenate input
file paths to the given path to save input files to the directory.
Previously, path concatenation didn't handle Windows drive letters
so it could generate invalid paths such as "C:\D:\foo". It also didn't
handle ".." path components, so it could produce some bad paths
such as "foo/../../etc/passwd".

In this patch, Windows drive letters and ".." are removed before
concatenating paths.

Differential Revision: http://reviews.llvm.org/D19551

llvm-svn: 267600
2016-04-26 20:36:46 +00:00
Davide Italiano e53e6e9f37 [ELF] Simplify. Pointed out by Rui Ueyama.
llvm-svn: 267523
2016-04-26 05:51:37 +00:00
Davide Italiano 034f58a9bd [ELF] Introduce --reproduce flag.
--reproduce dumps the object files in a directory chosen
(preserving the file system layout) and the linker invocation
so that people can create an archive and upload for debugging.

Differential Revision:  http://reviews.llvm.org/D19494

llvm-svn: 267497
2016-04-26 00:22:24 +00:00
Davide Italiano bfccefd514 [ELF] Reinstate 'else' which was previously removed.
It turns out it's actually needed.

llvm-svn: 267358
2016-04-24 18:23:21 +00:00
Davide Italiano 7d32a4d27f [ELF] Simplify. Remove unneeded else. NFC.
llvm-svn: 267333
2016-04-24 07:19:32 +00:00
Rui Ueyama 1e9e615f92 LTO: Merge -lto-no-discard-value-names with -save-temps.
This patch is to remove -lto-no-discard-value-names flag and
instead to use -save-temps as we discussed in the post-commit
review thread for r267020.

Differential Revision: http://reviews.llvm.org/D19437

llvm-svn: 267230
2016-04-22 21:43:10 +00:00
Peter Collingbourne 66ac1d6152 ELF: Implement basic support for --version-script.
This patch only implements support for version scripts of the form:
  { [ global: symbol1; symbol2; [...]; symbolN; ] local: *; };
No wildcards are supported, other than for the local entry. Symbol versioning
is also not supported.

It works by introducing a new Symbol flag which tracks whether a symbol
appears in the global section of a version script.

This patch also simplifies the logic in SymbolBody::isPreemptible(), and
teaches it to handle the case where symbols with default visibility in DSOs
do not appear in the dynamic symbol table because of a version script.

Fixes PR27482.

Differential Revision: http://reviews.llvm.org/D19430

llvm-svn: 267208
2016-04-22 20:21:26 +00:00
Rui Ueyama 630a382ba1 Reorganize LinkerDriver::link and add comments. NFC.
llvm-svn: 267201
2016-04-22 19:58:47 +00:00
Peter Collingbourne 3a35c4546d ELF: Scan for undefined symbols in shlibs and symbols in dynamic lists before LTO.
This ensures that these features work correctly with bitcode files.

llvm-svn: 267188
2016-04-22 18:47:52 +00:00
Peter Collingbourne 760e583e22 ELF: Implement --export-dynamic-symbol.
llvm-svn: 267184
2016-04-22 18:44:06 +00:00
Peter Collingbourne dadcc17ead ELF: Move Visibility, IsUsedInRegularObj and MustBeInDynSym flags to Symbol.
These are properties of a symbol name, rather than a particular instance
of a symbol in an object file. We can simplify the code by collecting these
properties in Symbol.

The MustBeInDynSym flag has been renamed ExportDynamic, as its semantics
have been changed to be the same as those of --dynamic-list and
--export-dynamic-symbol, which do not cause hidden symbols to be exported.

Differential Revision: http://reviews.llvm.org/D19400

llvm-svn: 267183
2016-04-22 18:42:48 +00:00
Davide Italiano 5abcb3cc5b [LTO] Discard names for values that are not global by default.
Rafael reported on the mailing list that this reduces peak memory
usage while linking llvm-as by 15%. It makes sense to make it
the default, and introduce an inverse knob -lto-no-discard-value-names
for those who want to restore the old behavior.

llvm-svn: 267020
2016-04-21 17:46:38 +00:00
Davide Italiano 3c0410d09d [LTO] Discard names for Values that are not global.
This is not on by default (but it might be in the future).
The knob to enable the optimization is -lto-discard-value-names.

llvm-svn: 266953
2016-04-21 04:46:22 +00:00
Rui Ueyama 07320e4030 ELF: Template LinkerScript class.
Originally, linker scripts were basically an alternative way to specify
options to the command line options. But as we add more features to hanlde
symbols and sections, many member functions needed to be templated.
Now most the members are templated. It is probably time to template the
entire class.

Previously, LinkerScript is an executor of the linker script as well as
a storage of linker script configurations. This is not suitable to template
the class because when we are reading linker script files, we don't know
the ELF type yet, so we can't instantiate ELF-templated classes.

In this patch, I defined a new class, ScriptConfiguration, to store
linker script configurations. ScriptParser writes parse results to it,
and LinkerScript uses them.

Differential Revision: http://reviews.llvm.org/D19302

llvm-svn: 266908
2016-04-20 20:13:41 +00:00
Davide Italiano bc176631cd [LTO] Implement parallel Codegen for LTO using splitCodeGen.
Parallelism level can be chosen using the new --lto-jobs=K option
where K is the number of threads used for CodeGen. It currently
defaults to 1.

llvm-svn: 266484
2016-04-15 22:38:10 +00:00
Rafael Espindola 38c67a27fe Store a Symbol for EntrySym.
This makes it impossible to forget to call repl on the SymbolBody.

llvm-svn: 266432
2016-04-15 14:41:56 +00:00
Rafael Espindola 3fa7352fc7 Fix warning about unused variable.
llvm-svn: 266232
2016-04-13 19:09:48 +00:00
Rafael Espindola ab14c88984 git-clang-format. NFC.
llvm-svn: 266231
2016-04-13 19:07:40 +00:00
Adhemerval Zanella 9df0720766 ELF: Implement --dynamic-list
This patch implements the --dynamic-list option, which adds a list of
global symbol that either should not be bounded by default definition
when creating shared libraries, or add in dynamic symbol table in the
case of creating executables.

The patch modifies the ScriptParserBase class to use a list of Token
instead of StringRef, which contains information if the token is a
quoted or unquoted strings. It is used to use a faster search for
exact match symbol name.

The input file follow a similar format of linker script with some
simplifications (it does not have scope or node names). It leads
to a simplified parser define in DynamicList.{cpp,h}.

Different from ld/gold neither glob pattern nor mangled names
(extern 'C++') are currently supported.

llvm-svn: 266227
2016-04-13 18:51:11 +00:00
George Rimar 2a78fceb2c [ELF] - Change -t implementation to print which archive members are used.
Previously each archive file was reported no matter were it's member used or not,
like:
lib/libLLVMSupport.a

Now lld prints line for each used internal file, like:
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/StringSaver.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/Host.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/ConvertUTF.c.o)

That should be consistent with what gold do.

This fixes PR27243.

Differential revision: http://reviews.llvm.org/D19011

llvm-svn: 266220
2016-04-13 18:07:57 +00:00
Rafael Espindola 9b3f99e50f Devide _gp in the same spot as other mips symbols. NFC.
The test changes are just because of the symbol order.

llvm-svn: 266037
2016-04-12 02:24:43 +00:00
Rui Ueyama 6c8b0c1b96 Use EM_NONE instead of 0 to represent an invalid value. NFC.
llvm-svn: 265750
2016-04-07 23:54:33 +00:00
Rui Ueyama d86ec30168 ELF: Add --build-id=sha1 option.
llvm-svn: 265748
2016-04-07 23:51:56 +00:00
Rui Ueyama 3a41be277a ELF: Implement --build-id=md5.
Previously, we supported only one hash function, FNV-1, so
BuildIdSection directly handled hash computation. In this patch,
I made BuildIdSection an abstract class and defined two subclasses,
BuildIdFnv1 and BuildIdMd5.

llvm-svn: 265737
2016-04-07 22:49:21 +00:00
Rui Ueyama fc6a4b045f ELF: Add --strip-debug option.
If --strip-debug option is given, then all sections whose names start
with ".debug" are removed from output.

llvm-svn: 265722
2016-04-07 21:04:51 +00:00
Rui Ueyama 8c76487ee5 ELF: Add --no-gnu-unique option.
When the option is specified, then all STB_GNU_UNIQUE symbols are
converted to STB_GLOBAL symbols.

llvm-svn: 265717
2016-04-07 20:41:41 +00:00
Rui Ueyama f8baa66056 ELF: Implement --start-lib and --end-lib
start-lib and end-lib are options to link object files in the same
semantics as archive files. If an object is in start-lib and end-lib,
the object is linked only when the file is needed to resolve
undefined symbols. That means, if an object is in start-lib and end-lib,
it behaves as if it were in an archive file.

In this patch, I introduced a new notion, LazyObjectFile. That is
analogous to Archive file type, but that works for a single object
file instead of for an archive file.

http://reviews.llvm.org/D18814

llvm-svn: 265710
2016-04-07 19:24:51 +00:00
Rafael Espindola ccfe3cb3d6 Don't store an Elf_Sym for most symbols.
Our symbol representation was redundant, and some times would get out of
sync. It had an Elf_Sym, but some fields were copied to SymbolBody.

Different parts of the code were checking the bits in SymbolBody and
others were checking Elf_Sym.

There are two general approaches to fix this:
* Copy the required information and don't store and Elf_Sym.
* Don't copy the information and always use the Elf_Smy.

The second way sounds tempting, but has a big problem: we would have to
template SymbolBody. I started doing it, but it requires templeting
*everything* and creates a bit chicken and egg problem at the driver
where we have to find ELFT before we can create an ArchiveFile for
example.

As much as possible I compared the test differences with what gold and
bfd produce to make sure they are still valid. In most cases we are just
adding hidden visibility to a local symbol, which is harmless.

In most tests this is a small speedup. The only slowdown was scylla
(1.006X). The largest speedup was clang with no --build-id, -O3 or
--gc-sections (i.e.: focus on the relocations): 1.019X.

llvm-svn: 265293
2016-04-04 14:04:16 +00:00
Davide Italiano 842fa53026 [LTO] Implement -disable-verify, which disables bitcode verification.
So, there are some cases when the IR Linker produces a broken
module (which doesn't pass the verifier) and we end up asserting
inside the verifier. I think it's always a bug producing a module
which does not pass the verifier but there are some cases in which
people can live with the broken module (e.g. if only DebugInfo
metadata are broken). The gold plugin has something similar.

This commit is motivated by a situation I found in the
wild. It seems that somebody else discovered it independently
and reported in PR24923.

llvm-svn: 265258
2016-04-03 03:39:09 +00:00
Davide Italiano 8848d44e46 [LTO] Reject invalid optimization levels.
llvm-svn: 265255
2016-04-03 02:41:15 +00:00
Davide Italiano 887d76c392 [LTO] Fix -save-temps in case -o is not specified.
Currently we create a file called .lto.bc. In UNIX,
ls(1) by default doesn't show up files starting with
a dot, as they're (only by convention) hidden.
This makes the output of -save-temps a little bit
hard to find. Use "a.out.lto.bc" instead if the
output file is not specified.

While here, change an existing -save-temps test to
exercise this more interesting behaviour.

llvm-svn: 265254
2016-04-03 02:16:56 +00:00
Rui Ueyama 7e71c61a7a Rename a variable. NFC.
We had variables MB and Mb in this function. Rename of one them.

llvm-svn: 265237
2016-04-02 19:09:07 +00:00
Rui Ueyama d1aa97b5c2 Do not return early.
Early return in this context is a bit confusing, so avoid doing it.

llvm-svn: 265236
2016-04-02 18:52:23 +00:00
Rui Ueyama 1fc5d48877 Move code to initialize LLVM to one place.
llvm-svn: 265235
2016-04-02 18:18:44 +00:00
Sean Silva abd25c9b3e Call cl::ParseCommandLineOptions from the driver.
Thanks to Rui for the suggestion; this simplifies things.

llvm-svn: 265213
2016-04-02 04:08:02 +00:00
Sean Silva 242bbdb7bf Fix MSVC build after r265206
c:\b\slave\sanitizer-windows\llvm\tools\lld\elf\Config.h(94) : error C2797: 'lld:🧝:Configuration::MLlvm': list initialization inside member initializer list or non-static data member initializer is not implemented

llvm-svn: 265207
2016-04-02 01:51:51 +00:00
Sean Silva 8e4ad5dbf8 PR27104: Add -mllvm option
The argv[0] is based on the analogous thing in clang.

llvm-svn: 265206
2016-04-02 01:39:56 +00:00
Peter Collingbourne d418b1da38 ELF: Correctly handle --whole-archive for thin archives.
Differential Revision: http://reviews.llvm.org/D18669

llvm-svn: 265073
2016-03-31 23:12:18 +00:00
Rui Ueyama b339b6de0d Define a utility function to read -O and lto-O options.
llvm-svn: 265056
2016-03-31 21:15:31 +00:00
Peter Collingbourne ed22f9b6f1 ELF: Add flag for controlling LTO optimization level.
Differential Revision: http://reviews.llvm.org/D18667

llvm-svn: 265053
2016-03-31 21:00:27 +00:00
Ed Maste e2b7677c9e lld: accept and ignore _fbsd suffix in emulation name
Differential Revision:	http://reviews.llvm.org/D18661

llvm-svn: 265044
2016-03-31 20:26:30 +00:00
George Rimar 1e4b39f184 [ELF, PR27091] - Implemented -t/--trace option
-t/--trace
Print the names of the input files as ld processes them.
This fixes https://llvm.org/bugs/show_bug.cgi?id=27091.

Differential revision: http://reviews.llvm.org/D18517

llvm-svn: 264708
2016-03-29 08:45:40 +00:00
George Rimar 177f7bcee8 Avoid using braces. NFC.
llvm-svn: 263707
2016-03-17 11:00:27 +00:00
George Rimar 786e866fea [ELF] - -pie/--pic-executable option implemented
-pie
--pic-executable

Create a position independent executable.  This is currently only
 supported on ELF platforms.  Position independent executables are
 similar to shared libraries in that they are relocated by the
 dynamic linker to the virtual address the OS chooses for them
 (which can vary between invocations).  Like normal dynamically
 linked executables they can be executed and symbols defined in the
 executable cannot be overridden by shared libraries.

Differential revision: http://reviews.llvm.org/D18183

llvm-svn: 263693
2016-03-17 05:57:33 +00:00
Davide Italiano 1568868044 [ELF] Use braces for muti-line if(s).
Reported by: Joerg Sonnenberg.

llvm-svn: 263690
2016-03-17 04:28:41 +00:00
Davide Italiano 00a7cf9ffe [ELF] Ignore _GLOBAL_OFFSET_TABLE_ symbol in shared libs.
This fixes PR26705.

Differential Revision:  http://reviews.llvm.org/D18166

llvm-svn: 263594
2016-03-15 22:24:58 +00:00
Rui Ueyama 15fa035477 ELF: Fix use-after-free problem.
Fixes pr26908. This patch is based on Filipe Cabecinhas'
patch (http://reviews.llvm.org/D18167)

http://reviews.llvm.org/D18169

llvm-svn: 263569
2016-03-15 18:20:50 +00:00
Rui Ueyama 64bd8df458 Error messages should start with lowercase letters.
llvm-svn: 263496
2016-03-14 21:31:07 +00:00
George Rimar 343580097d [ELF] implement --warn-common/--no-warn-common
-warn-common
Warn when a common symbol is combined with another common symbol
or with a symbol definition.  Unix linkers allow  this  somewhat
sloppy  practice, but linkers on some other operating systems do
not.  This option allows you to  find  potential  problems  from
combining global symbols.

Differential revision: http://reviews.llvm.org/D17998

llvm-svn: 263413
2016-03-14 09:19:30 +00:00
Rui Ueyama 6c5638b01a ELF: Add `Rela` member variable to Config.
The member is true if we want to create relocatin sections with RELA
instead of REL.

llvm-svn: 263387
2016-03-13 20:10:20 +00:00
Rui Ueyama 6eafa7fb23 Do not return a bool value from error().
error returned true if there was an error. This allows us to replace
the code like this

  if (EC) {
    error(EC, "something failed");
    return;
  }

with

  if (error(EC, "something failed"))
    return;

I thought that that was a good idea, but it turned out that we only
have two places to use this pattern. So this patch removes that feature.

llvm-svn: 263362
2016-03-13 04:25:41 +00:00
Rui Ueyama 7f4a492f98 "Windows" is a product name, so it should be spelled correctly.
llvm-svn: 263357
2016-03-13 03:17:42 +00:00
George Rimar 777f96304e Recommit of r263252, [ELF] - Change all messages to lowercase to be consistent.
which was reverted because included
unrelative changes by mistake.

Original commit message:

[ELF] - Change all messages to lowercase to be consistent.

That is directly opposite to http://reviews.llvm.org/D18045,
which was reverted.

This patch changes all messages to start from lowercase letter if
they were not before.

That is done to be consistent with clang.

Differential revision: http://reviews.llvm.org/D18085

llvm-svn: 263337
2016-03-12 08:31:34 +00:00
Rui Ueyama 634ddf0bec ELF: Implement --build-id.
This patch implements --build-id. After the linker creates an output file
in the memory buffer, it computes the FNV1 hash of the resulting file
and set the hash to the .note section as a build-id.

GNU ld and gold have the same feature, but their default choice of the
hash function is different. Their default is SHA1.

We made a deliberate choice to not use a secure hash function for the
sake of performance. Computing a secure hash is slow -- for example,
MD5 throughput is usually 400 MB/s or so. SHA1 is slower than that.

As a result, if you pass --build-id to gold, then the linker becomes about
10% slower than that without the option. We observed a similar degradation
in an experimental implementation of build-id for LLD. On the other hand,
we observed only 1-2% performance degradation with the FNV hash.

Since build-id is not for digital certificate or anything, we think that
a very small probability of collision is acceptable.

We considered using other signals such as using input file timestamps as
inputs to a secure hash function. But such signals would have an issue
with build reproducibility (if you build a binary from the same source
tree using the same toolchain, the build id should become the same.)

GNU linkers accepts --build-id=<style> option where style is one of
"MD5", "SHA1", or an arbitrary hex string. That option is out of scope
of this patch.

http://reviews.llvm.org/D18091

llvm-svn: 263292
2016-03-11 20:51:53 +00:00
Rui Ueyama f714955402 Revert r263252: "[ELF] - Change all messages to lowercase to be consistent."
This reverts commit r263252 because the change contained unrelated changes.

llvm-svn: 263272
2016-03-11 18:46:51 +00:00
George Rimar 96bcdae1a5 [ELF] - Change all messages to lowercase to be consistent.
That is directly opposite to http://reviews.llvm.org/D18045,
which was reverted.

This patch changes all messages to start from lowercase letter if
they were not before.

That is done to be consistent with clang.

Differential revision: http://reviews.llvm.org/D18085

llvm-svn: 263252
2016-03-11 16:40:55 +00:00
George Rimar 5761042db7 This reverts the r263125
It was discussed to make all messages be 
lowercase to be consistent with clang.
(also reverts the r263128 which fixed 
build bot fail after r263125)

Original commit message:
[ELF] - Consistent spelling for error/warning messages

Previously error and warnings were not consistent in lld.
Some of them started from lowercase letter, others from
uppercase. Also there was one or two which had a dot at the end.
This patch changes all messages to start from uppercase letter if
they were not before.

Differential revision: http://reviews.llvm.org/D18045

llvm-svn: 263240
2016-03-11 14:43:02 +00:00
George Rimar 56e0d53e92 [ELF] - Move initSymbols() to Driver.cpp. NFC.
That is followup for http://reviews.llvm.org/D18047
patch. initSymbols() moved to Driver.cpp and made static.

llvm-svn: 263214
2016-03-11 10:07:18 +00:00
Rui Ueyama e98095026f ELF: Add --thread option and partially parallelize writeTo().
This patch adds --thread option and use parallel_for_each to write
sections in regular OutputSections.

This is the first patch to use more than one threads.

Note that --thread is off by default because it is experimental.
At this moment I still want to focus on single thread performance
because multi-threading is not a magic wand to fix performance
problems after all. It is generally very hard to make a slow program
faster by threads. Therefore, I want to make the linker as efficient
as possible first and then look for opportunity to make it even faster
using more than one core.

Here are some numbers to link programs with and without --threads
and using GNU gold. Numbers are in seconds.

Clang
  w/o --threads 0.697
  w --threads   0.528
  gold          1.643

Scylla
  w/o --threads 5.032
  w --threads   4.935
  gold          6.791

GNU gold
  w/o --threads 0.550
  w --threads   0.551
  gold          0.737

I limited the number of cores these processes can use to 4 using
perf command, so although my machine has 20 physical cores, the
performance gain I observed should be reproducible with a machine
which is not as beefy as mine.

llvm-svn: 263190
2016-03-11 04:23:12 +00:00
George Rimar 5a3dcf4edf [ELF] - Do not call doInitSymbols for all ELFTs
It looks a bit wierd that we have to initialize symbols for all ELFT 
types when we use only one ELFT for link. We can only init those
that we need. Patch fixes it.

Differential revision: http://reviews.llvm.org/D18047

llvm-svn: 263133
2016-03-10 17:38:49 +00:00
George Rimar e094388861 [ELF] - Consistent spelling for error/warning messages
Previously error and warnings were not consistent in lld.
Some of them started from lowercase letter, others from
uppercase. Also there was one or two which had a dot at the end.
This patch changes all messages to start from uppercase letter if
they were not before.

Differential revision: http://reviews.llvm.org/D18045

llvm-svn: 263125
2016-03-10 16:58:34 +00:00
Sean Silva 03e41ee6a7 [lto] Initialize asmparsers.
Summary:
They are needed for inline asm during LTO.

In particular we hit the report_fatal_error on
llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp:138

    LLVM ERROR: Inline asm not supported by this streamer because we don't have an asm parser for this target

Reviewers: ruiu, rafael

Subscribers: Bigcheese, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18027

llvm-svn: 263094
2016-03-10 04:58:52 +00:00
Rui Ueyama 2b4df612ec Simplify. NFC.
In this context, MBRef.getBufferIdentifier() == Path.

llvm-svn: 263061
2016-03-09 21:15:17 +00:00
Sean Silva 35ef3d95eb [lto] Add beginning of -save-temps option.
Summary:
This is useful for debugging issues with LTO.
The option follows the analogous option in ld64 and the gold plugin (per
Rafael's suggestion).

For starters, this only dumps the combined bitcode file.
In a future patch I will add dumping for the .o file.

The naming of the output follows ld64's convention which is slightly more
consistent IMO (consistent `.lto.<extension>` for all the files).

Reviewers: rafael, ruiu

Subscribers: joker.eph, Bigcheese, llvm-commits

Differential Revision: http://reviews.llvm.org/D18006

llvm-svn: 263055
2016-03-09 20:01:08 +00:00
Rafael Espindola 0650192094 Revert "ELF: Add /lib and /usr/lib as default search paths."
It was causing errors like

/lib/libc.so.6 is incompatible with elf_x86_64

when linking on Fedora.

Every system has different default paths. It seems better to just trust
the driver to pass the correct -L options.

This reverts commit 262910.

llvm-svn: 262941
2016-03-08 17:13:12 +00:00
Rui Ueyama 3f9f09265b ELF: Rename NoInhibitExec -> NoinhibitExec.
The variables corresponding to command line options are named mechanically.
Because the option for the variable is -noinhibit-exec and not -no-inhibit-exec,
it should be name this way.

llvm-svn: 262911
2016-03-08 04:06:29 +00:00
Rui Ueyama b9883d55d8 ELF: Add /lib and /usr/lib as default search paths.
GNU ld and gold have these paths as default search paths.
If you don't want these directories, pass -nostdlib.

llvm-svn: 262910
2016-03-08 04:06:27 +00:00
Rafael Espindola 75714f618c Rename 'fatal' to 'check' when it doesn't always fail.
llvm-svn: 262666
2016-03-03 22:24:39 +00:00
Rafael Espindola 1130935c4a Simplify error handling.
This makes fatal return T when there is no error. This avoids the need
for quite a few temporaries.

llvm-svn: 262626
2016-03-03 16:21:44 +00:00
Rui Ueyama a453c0a5ad Merge DarwinLdDriver and Driver.
Now that DarwinLdDriver is the only derived class of Driver.
This patch merges them and actually removed the class because
they can now just be non-member functions. This change simplifies
a common header, Driver.h.

http://reviews.llvm.org/D17788

llvm-svn: 262502
2016-03-02 19:08:05 +00:00
George Rimar 262b927d36 [ELF] - handle of command line options incompatible with -r
Patch handles the command line options
incompatible with relocatable output.

Differential revision: http://reviews.llvm.org/D17758

llvm-svn: 262377
2016-03-01 19:38:51 +00:00
Rui Ueyama 7c82dbf333 Remove unused #include.
llvm-svn: 262169
2016-02-28 03:27:09 +00:00
Rui Ueyama 1eb9f44118 ELF: Add --help option.
llvm-svn: 262168
2016-02-28 03:18:09 +00:00
Rui Ueyama 1abcf370fd ELF: Add --version option.
llvm-svn: 262167
2016-02-28 03:18:07 +00:00
Rafael Espindola e0df00b91f Rename elf2 to elf.
llvm-svn: 262159
2016-02-28 00:25:54 +00:00
Rui Ueyama 10bd283041 ELF: Define log() to print out message if --verbose is given.
llvm-svn: 261919
2016-02-25 18:56:01 +00:00
Rui Ueyama 0b28952993 ELF: Implement ICF.
This patch implements the same algorithm as LLD/COFF's ICF. I'm
not going to repeat the same description about how it works, so you
want to read the comment in ICF.cpp in this patch if you want to know
the details. This algorithm should be more powerful than the ICF
algorithm implemented in GNU gold. It can even merge mutually-recursive
functions (which is harder than one might think).

ICF is a fairly effective size optimization. Here are some examples.

 LLD:   37.14 MB -> 35.80 MB (-3.6%)
 Clang: 59.41 MB -> 57.80 MB (-2.7%)

The lacking feature is "safe" version of ICF. This merges all
identical sections. That is not compatible with a C/C++ language
requirement that two distinct functions must have distinct addresses.

But as long as your program do not rely on the pointer equality
(which is in many cases true), your program should work with the
feature. LLD works fine for example.

GNU gold implements so-called "safe ICF" that identifies functions
that are safe to merge by heuristics -- for example, gold thinks
that constructors are safe to merge because there is no way to
take an address of a constructor in C++. We have a different idea
which David Majnemer suggested that we add NOPs at beginning of
merged functions so that two or more pointers can have distinct
values. We can do whichever we want, but this patch does not
include neither.

http://reviews.llvm.org/D17529

llvm-svn: 261912
2016-02-25 18:43:51 +00:00
George Rimar 58941ee12a [ELF2] - Basic implementation of -r/--relocatable
-r, -relocatable - Generate relocatable output

Currently does not have support for files containing 
relocation sections with entries that refer to local 
symbols (like rel[a].eh_frame which refer to sections
and not to symbols)

Differential revision: http://reviews.llvm.org/D14382

llvm-svn: 261838
2016-02-25 08:23:37 +00:00
Rui Ueyama c89bff2ce1 Handle bitcode files in archive files with --whole-archive.
This patch moves BitcodeFile instantiation into createObjectFile.
Previously, we handle bitcode files outside that function and did
not handle for --whole-archive.

http://reviews.llvm.org/D17527

llvm-svn: 261663
2016-02-23 18:17:11 +00:00
Rafael Espindola 9f77ef0c08 Add initial LTO support.
llvm-svn: 260726
2016-02-12 20:54:57 +00:00
Rui Ueyama e9c5806593 ELF: Remove use of MapVector from LinkerScript.
We don't have to use a MapVector here. Instead, just std::vector suffices.

llvm-svn: 260724
2016-02-12 20:41:43 +00:00
Rui Ueyama f9de0d6904 ELF: Remove readLinkerScript and define LinkerScript::read instead.
llvm-svn: 260598
2016-02-11 21:38:55 +00:00
Rui Ueyama c1c282a04e ELF: Release Target at end of link().
Previously, Target held a value until a new value is assigned to the
variable. That was a benign leak -- that was not an unbounded leak
and didn't grab any resources except a small amount of memory. But
it is better to fix than leaving as is.

llvm-svn: 260592
2016-02-11 21:18:01 +00:00
Rui Ueyama 717677af35 ELF: Create LinkerScript class to move code out of Writer.
Previously, we had code for linker scripts in Writer. This patch
separates that as LinkerScript class. The class provides a few
functions to query linker scripts and is also a container of some
linker-script-specific information.

Hopefully, Writer will only implement the default behavior and let
the new class handle gotchas regarding linker scripts.

llvm-svn: 260591
2016-02-11 21:17:59 +00:00
Simon Atanasyan b76108a63a [ELF][MIPS] Add comments to describe __gnu_local_gp magic symbol
NFC. Follow-up to r259781.

llvm-svn: 260027
2016-02-07 12:09:40 +00:00
Simon Atanasyan 597df21eb2 [ELF][MIPS] Add handling for __gnu_local_gp symbol
This symbol is a "fake" symbol like "_gp_disp" and denotes
the GOT + 0x7FF0 value.

llvm-svn: 259781
2016-02-04 12:09:49 +00:00
Rui Ueyama b6940115a8 ELF: Make link() to take an output stream to which error messages are written.
http://reviews.llvm.org/D16668

llvm-svn: 259597
2016-02-02 22:49:32 +00:00
Rui Ueyama 21eecb4f14 Re-submit ELF: Report multiple errors from the driver.
This reverts r259395 which reverted r259143.

llvm-svn: 259572
2016-02-02 21:13:09 +00:00
George Rimar 5c36e5938d [ELF] Implemented -Bsymbolic-functions command line option
-Bsymbolic-functions: 
When creating a shared library, bind references to global 
function symbols to the definition within the shared library, if any.

This patch also fixed behavior of already existent -Bsymbolic:
previously PLT entries were created even if -Bsymbolic was specified.

Differential revision: http://reviews.llvm.org/D16411

llvm-svn: 259481
2016-02-02 09:28:53 +00:00
Rui Ueyama 71c066d8cf ELF: Include archive names in error messages.
If object files are drawn from archive files, the error message should
be something like "conflict symbols in foo.a(bar.o) and baz.o" instead
of "conflict symbols in bar.o and baz.o". This patch implements that.

llvm-svn: 259475
2016-02-02 08:22:41 +00:00
Nico Weber f07bd3b72d Revert r259143, it broke check-lld on Windows (see PR26388).
llvm-svn: 259395
2016-02-01 20:03:53 +00:00
Rui Ueyama 16ba669c87 ELF: Report duplicate symbols as many as possible instead of the first one.
http://reviews.llvm.org/D16647

llvm-svn: 259233
2016-01-29 19:41:13 +00:00
George Rimar 2c9b7bd326 Replace StringRef with std::string in LinkerDriver::addLibrary(StringRef Name) because std::string is destroyed after assigning what fills the buffer with garbage and StringRef is no more valid.
That fixes few failing tests under windows+msvs2015(debug).

llvm-svn: 259186
2016-01-29 10:52:52 +00:00
Rui Ueyama 1940424632 ELF: Report multiple errors from the driver.
This patch let the driver keep going until it parses all
command line options.

http://reviews.llvm.org/D16645

llvm-svn: 259143
2016-01-29 01:54:52 +00:00
Rui Ueyama 64cfffd333 ELF: Rename error -> fatal and redefine error as a non-noreturn function.
In many situations, we don't want to exit at the first error even in the
process model. For example, it is better to report all undefined symbols
rather than reporting the first one that the linker picked up randomly.

In order to handle such errors, we don't need to wrap everything with
ErrorOr (thanks for David Blaikie for pointing this out!) Instead, we
can set a flag to record the fact that we found an error and keep it
going until it reaches a reasonable checkpoint.

This idea should be applicable to other places. For example, we can
ignore broken relocations and check for errors after visiting all relocs.

In this patch, I rename error to fatal, and introduce another version of
error which doesn't call exit. That function instead sets HasError to true.
Once HasError becomes true, it stays true, so that we know that there
was an error if it is true.

I think introducing a non-noreturn error reporting function is by itself
a good idea, and it looks to me that this also provides a gradual path
towards lld-as-a-library (or at least embed-lld-to-your-program) without
sacrificing code readability with lots of ErrorOr's.

http://reviews.llvm.org/D16641

llvm-svn: 259069
2016-01-28 18:40:06 +00:00
Rafael Espindola 3a6a0a0109 Delete addIgnoredStrong.
It is not needed now that we resolve symbols is shared libraries
correctly.

llvm-svn: 258104
2016-01-19 00:05:54 +00:00
George Rimar f6bc65a3b2 Reapply r257753 with fix:
Added check for terminator CIE/FDE which has zero data size.
void EHOutputSection<ELFT>::addSectionAux(
...
 // If CIE/FDE data length is zero then Length is 4, this
 // shall be considered a terminator and processing shall end.
    if (Length == 4)
      break;
...

After this "Bug 25923 - lld/ELF2 linked application crashes if exceptions were used." is fixed for me. Self link of clang also works.

Initial commit message:
[ELF] - implemented --eh-frame-hdr command line option.

--eh-frame-hdr
Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header.

Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr.
This section contains a lookup table for quick binary search of FDEs.
Detailed info can be found here:
http://www.airs.com/blog/archives/462

Differential revision: http://reviews.llvm.org/D15712

llvm-svn: 257889
2016-01-15 13:34:52 +00:00
Rui Ueyama 5f91ace828 Revert r257753: "[ELF] - implemented --eh-frame-hdr command line option."
This reverts commit r257753 because we cannot link Clang with this patch.

llvm-svn: 257797
2016-01-14 20:32:19 +00:00
George Rimar 28f4fbe480 [ELF] - implemented --eh-frame-hdr command line option.
--eh-frame-hdr
Request creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME" segment header.

Both gold and the GNU linker support an option --eh-frame-hdr which tell them to construct a header for all the .eh_frame sections. This header is placed in a section named .eh_frame_hdr and also in a PT_GNU_EH_FRAME segment. At runtime the unwinder can find all the PT_GNU_EH_FRAME segments by calling dl_iterate_phdr.
This section contains a lookup table for quick binary search of FDEs.
Detailed info can be found here:
http://www.airs.com/blog/archives/462

Differential revision: http://reviews.llvm.org/D15712

llvm-svn: 257753
2016-01-14 10:30:32 +00:00