Commit Graph

387 Commits

Author SHA1 Message Date
Rui Ueyama 58841b45d0 Remove Driver::OwningMB and instead use make().
We managed new MemoryBuffers in different ways in LinkerScript.cpp and
Driver.cpp. With this patch, they are managed in the same way.

llvm-svn: 290411
2016-12-23 03:19:09 +00:00
Simon Atanasyan 8f7d28122c [ELF] Do not warn about missed entry symbol in case of relocatable output
Relocatable file does not need to have an entry symbol so the warning is
useless in that case.

llvm-svn: 290206
2016-12-20 22:24:45 +00:00
Rui Ueyama c207a89c91 Remove `Compressed` member from InputSectionData.
This value is used only once, and we can compute a value.
So we don't need to save it.

llvm-svn: 290164
2016-12-20 05:47:55 +00:00
Rui Ueyama 398f55f6f6 Set Config->ColorDiagnostics early so that all error messages are colored.
Previously, some errors that were checked before we set to
Config->ColorDiagnostics weren't colored. This patch moves the code
to set the variable so that such error messages are colored just like
other error messages.

llvm-svn: 290157
2016-12-20 02:17:24 +00:00
Rui Ueyama 312703116f Simplify type of Config->SymbolOrderingFile.
That variable was of type DenseMap<StringRef, unsigned>, but the
unsigned numbers needed to be monotonicly increasing numbers because
the implementation that used the variable depended on that fact.
That was an implementation detail and shouldn't have leaked into Config.

This patch simplifies its type to std::vector<StringRef>.

llvm-svn: 290151
2016-12-20 01:51:08 +00:00
Rui Ueyama a8529e2cb7 Inline a small function.
llvm-svn: 290150
2016-12-20 01:34:31 +00:00
George Rimar 2bb88ab5e0 [ELF] - Implemented --retain-symbols-file option
--retain-symbols-file=filename
Retain only the symbols listed in the file filename, discarding all others. 
filename is simply a flat file, with one symbol name per line. This option 
is especially useful in environments (such as VxWorks) where a large global 
symbol table is accumulated gradually, to conserve run-time memory.

Note: though documentation says "--retain-symbols-file does not discard 
undefined symbols, or symbols needed for relocations.", both bfd and gold 
do that, and this patch too, like testcase show.

Differential revision: https://reviews.llvm.org/D27716

llvm-svn: 290122
2016-12-19 18:00:52 +00:00
Rui Ueyama 8f687f71fb Remove inappropriate use of CachedHashStringRef.
Use of CachedHashStringRef makes sense only when we reuse hash values.
Sprinkling it to all DenseMap has no benefits and just complicates data types.
Basically we shouldn't use CachedHashStringRef unless there is a strong
reason to to do so.

llvm-svn: 290076
2016-12-19 03:14:16 +00:00
Rui Ueyama 9381eb1045 Remove lld/Support/Memory.h.
I thought for a while about how to remove it, but it looks like we
can just copy the file for now. Of course I'm not happy about that,
but it's just less than 50 lines of code, and we already have
duplicate code in Error.h and some other places. I want to solve
them all at once later.

Differential Revision: https://reviews.llvm.org/D27819

llvm-svn: 290062
2016-12-18 14:06:06 +00:00
Rui Ueyama 3c04f8d790 Print a warning message if ENTRY() symbol is not found.
llvm-svn: 289146
2016-12-08 22:26:31 +00:00
Rui Ueyama 520d9169e6 Move Memory.{h,cpp} to lld/Support so that we can use them from COFF.
llvm-svn: 289084
2016-12-08 18:31:13 +00:00
Rafael Espindola d0ebd84c42 Change the implementation of --dynamic-list to use linker script parsing.
The feature is documented as
-----------------------------
The format of the dynamic list is the same as the version node
without scope and node name.  See *note VERSION:: for more
information.
--------------------------------

And indeed qt uses a dynamic list with an 'extern "C++"' in it. With
this patch we support that

The change to gc-sections-shared makes us match bfd. Just because we
kept bar doesn't mean it has to be in the dynamic symbol table.

The changes to invalid-dynamic-list.test and reproduce.s are because
of the new parser.

The changes to version-script.s are the only case where we change
behavior with regards to bfd, but I would like to see a mix of
--version-script and --dynamic-list used in the wild before
complicating the code.

llvm-svn: 289082
2016-12-08 17:54:26 +00:00
Rui Ueyama 6f6d46d497 Use `make` to simplify. NFC.
llvm-svn: 289081
2016-12-08 17:48:52 +00:00
Rui Ueyama 6dbf7ff747 Use make to instantiate Target and LinkerScript. NFC.
llvm-svn: 289079
2016-12-08 17:44:39 +00:00
Rui Ueyama e4eadb6a24 Split LinkerDriver::link. NFC.
llvm-svn: 289078
2016-12-08 17:44:37 +00:00
Rui Ueyama 34bf8677a4 Remove a special handling of AMDGPU entry points.
This is the last peculiar semantics left in the linker. If you want to
always set an entry point to 0, you can pass `-e 0` to the linker.

Differential Revision: https://reviews.llvm.org/D27532

llvm-svn: 289077
2016-12-08 17:32:58 +00:00
Rafael Espindola d4db0b3748 Rename MaxPageSize to DefaultMaxPageSize to avoid confusion.
Thanks to Rui for the suggestion.

llvm-svn: 288982
2016-12-07 21:13:27 +00:00
Rafael Espindola 476d20764a Use the correct MaxPageSize.
Now Target->MaxPageSize is only used as the default value of
Config->MaxPageSize.

llvm-svn: 288974
2016-12-07 20:29:46 +00:00
Rui Ueyama 4de746f326 Add comments and reorder code a bit to clarify the intention. NFC.
llvm-svn: 288885
2016-12-07 04:45:34 +00:00
Rui Ueyama 9e5f5effe5 Make a decision about whether we should warn on missing entry or not early.
Config->WarnMissingEntry is a single-purpose boolean variable, and
I think it's easier to understand than Config->HasEntry.

llvm-svn: 288883
2016-12-07 04:06:21 +00:00
Rui Ueyama a1407c4fdf Simplify -e <number> option handling.
This patch is to parse the entry symbol name lazily.

llvm-svn: 288882
2016-12-07 03:23:06 +00:00
Petr Hosek 2f50fef095 [ELF] Shared libraries should have entry point
Shared libraries should have entry set following the same rules as for
regular binaries. The only difference is that in case the default entry
point (_start or __start) isn't found (unless it was set explicitly), we
shouldn't give a warning as in case of regular binaries.

Differential Revision: https://reviews.llvm.org/D27497

llvm-svn: 288878
2016-12-07 02:26:16 +00:00
Rafael Espindola 61d052d725 Don't discard .L symbol with -r.
They might be used by relocations.

Fixes pr31252.

llvm-svn: 288617
2016-12-04 08:34:17 +00:00
Rui Ueyama 244a435ae3 Factor out common code to a header.
llvm-svn: 288599
2016-12-03 21:24:51 +00:00
George Rimar d250618c3e [ELF] - Disable relro when -omagic specified.
--omagic is an option to create old-fashioned executables in which
.text segments are writable. Today, the option is still in use to
create special-purpose programs such as boot loaders. It doesn't
make sense to create PT_GNU_RELRO for such executables.

DIfferential revision: https://reviews.llvm.org/D27297

llvm-svn: 288579
2016-12-03 07:09:28 +00:00
Simon Atanasyan 9705ff74ed [ELF][MIPS] Restore Config->Threads for MIPS targets
llvm-svn: 288130
2016-11-29 10:24:00 +00:00
George Rimar 595a763f38 [ELF] - Implemented -N (-omagic) command line option.
-N (-omagic)
  Set the text and data sections to be readable and writable. 
  Also, do not page-align the data segment.

Differential revision: https://reviews.llvm.org/D26888

llvm-svn: 288123
2016-11-29 09:43:51 +00:00
George Rimar 18a3096282 [ELF] - Set Config->SingleRoRx differently. NFC.
Previously Config->SingleRoRx was set in
createFiles() and used HasSections.

This change moves it to readConfigs at place of
common flags handling, and adds logic that sets
this flag separatelly from ScriptParser if SECTIONS present.

llvm-svn: 288021
2016-11-28 10:11:10 +00:00
George Rimar 63bf011003 [ELF] - Implemented -no-rosegment.
--no-rosegment: Do not put read-only non-executable sections in their own segment

Differential revision: https://reviews.llvm.org/D26889

llvm-svn: 288020
2016-11-28 10:05:20 +00:00
Rui Ueyama 72b1ee2533 Make getColorDiagnostics return a boolean value instead of an enum.
Config->ColorDiagnostics was of type enum before. Now it is just a
boolean flag. Thanks Rafael for suggestion.

llvm-svn: 287978
2016-11-26 15:10:01 +00:00
Davide Italiano 3bfa081aa9 [ELF] Be compliant with LLVM and rename Lto into LTO. NFCI.
llvm-svn: 287967
2016-11-26 05:37:04 +00:00
Rui Ueyama 8c8818a58c Support -color-diagnostics={auto,always,never}.
-color-diagnostics=auto is default because that's the same as
Clang's default. When color is enabled, error or warning messages
are colored like this.

  error:
  <bold>ld.lld</bold> <red>error:</red> foo.o: no such file

  warning:
  <bold>ld.lld</bold> <magenta>warning:</magenta> foo.o: no such file

Differential Revision: https://reviews.llvm.org/D27117

llvm-svn: 287949
2016-11-25 20:27:32 +00:00
Rui Ueyama 6066641423 We shouldn't call parallle_for_each if -no-thread is given.
llvm-svn: 287948
2016-11-25 20:20:57 +00:00
Rui Ueyama 2555952ba8 Parallelize uncompress() and splitIntoPieces().
Uncompressing section contents and spliting mergeable section contents
into smaller chunks are heavy tasks. They scan entire section contents
and do CPU-intensive tasks such as uncompressing zlib-compressed data
or computing a hash value for each section piece.

Luckily, these tasks are independent to each other, so we can do that
in parallel_for_each. The number of input sections is large (as opposed
to the number of output sections), so there's a large parallelism here.

Actually the current design to call uncompress() and splitIntoPieces()
in batch was chosen with doing this in mind. Basically what we need to
do here is to replace `for` with `parallel_for_each`.

It seems this patch improves latency significantly if linked programs
contain debug info (which in turn contain lots of mergeable strings.)
For example, the latency to link Clang (debug build) improved by 20% on
my machine as shown below. Note that ld.gold took 19.2 seconds to do
the same thing.

Before:
    30801.782712 task-clock (msec)         #    3.652 CPUs utilized            ( +-  2.59% )
         104,084 context-switches          #    0.003 M/sec                    ( +-  1.02% )
           5,063 cpu-migrations            #    0.164 K/sec                    ( +- 13.66% )
       2,528,130 page-faults               #    0.082 M/sec                    ( +-  0.47% )
  85,317,809,130 cycles                    #    2.770 GHz                      ( +-  2.62% )
  67,352,463,373 stalled-cycles-frontend   #   78.94% frontend cycles idle     ( +-  3.06% )
 <not supported> stalled-cycles-backend
  44,295,945,493 instructions              #    0.52  insns per cycle
                                           #    1.52  stalled cycles per insn  ( +-  0.44% )
   8,572,384,877 branches                  #  278.308 M/sec                    ( +-  0.66% )
     141,806,726 branch-misses             #    1.65% of all branches          ( +-  0.13% )

     8.433424003 seconds time elapsed                                          ( +-  1.20% )

After:
    35523.764575 task-clock (msec)         #    5.265 CPUs utilized            ( +-  2.67% )
         159,107 context-switches          #    0.004 M/sec                    ( +-  0.48% )
           8,123 cpu-migrations            #    0.229 K/sec                    ( +- 23.34% )
       2,372,483 page-faults               #    0.067 M/sec                    ( +-  0.36% )
  98,395,342,152 cycles                    #    2.770 GHz                      ( +-  2.62% )
  79,294,670,125 stalled-cycles-frontend   #   80.59% frontend cycles idle     ( +-  3.03% )
 <not supported> stalled-cycles-backend
  46,274,151,813 instructions              #    0.47  insns per cycle
                                           #    1.71  stalled cycles per insn  ( +-  0.47% )
   8,987,621,670 branches                  #  253.003 M/sec                    ( +-  0.60% )
     148,900,624 branch-misses             #    1.66% of all branches          ( +-  0.27% )

     6.747548004 seconds time elapsed                                          ( +-  0.40% )

llvm-svn: 287946
2016-11-25 20:05:08 +00:00
Rui Ueyama f373dd76ce Remove HasError and use ErrorCount instead.
HasError was always true if ErrorCount > 0, so we can use ErrorCount instead.

llvm-svn: 287849
2016-11-24 01:43:21 +00:00
Rui Ueyama ac95f6bfcc Limit default maximum number of errors to 20.
This is in the context of https://llvm.org/bugs/show_bug.cgi?id=31109.
When LLD prints out errors for relocations, it tends to print out
extremely large number of errors (like millions) because it would
print out one error per relocation.

This patch makes LLD bail out if it prints out more than 20 errors.
You can configure the limitation using -error-limit argument.
-error-limit=0 means no limit.

I chose the flag name because Clang has the same feature as -ferror-limit.
"f" doesn't make sense to us, so I omitted it.

Differential Revision: https://reviews.llvm.org/D26981

llvm-svn: 287789
2016-11-23 18:15:37 +00:00
Simon Atanasyan 399ac5c3fb [ELF][MIPS] Turn Config->Threads off for MIPS targets
For now MipsGotSection class is not ready for concurrent access from
multiple threads. The problem is in the getPageEntryOffset method. It
changes state of MipsGotSection object and might be called from
different threads at the same time. So turn Threads off for this target.

It's a temporary solution. The patch fixes MipsGotSection::getPageEntryOffset
is almost ready.

Differential revision: https://reviews.llvm.org/D27035

llvm-svn: 287740
2016-11-23 05:25:02 +00:00
Eugene Leviant 7d7ff80f4b [ELF] Better error reporting for broken archives
Differential revision: https://reviews.llvm.org/D26852

llvm-svn: 287527
2016-11-21 09:28:07 +00:00
Rui Ueyama f7dfb2e250 Remove a file that is too short to be an independent file.
We have a .cpp and a .h for parseDynamicList(). This patch
moves the function to DriverUtil.cpp.

llvm-svn: 287468
2016-11-19 23:26:41 +00:00
Rui Ueyama 061f9286df Use Optional<std::string> instead of "" to represent a failure.
llvm-svn: 287456
2016-11-19 19:23:58 +00:00
George Rimar 0a94bffe12 [ELF] - Exit on --version call.
GNU linkers disagree here.
Though both -version and -v are mentioned
in help to print the version information, GNU ld just normally exits,
while gold can continue linking. We are compatible with ld.bfd here.

This fixes PR31057.

Differential revision: https://reviews.llvm.org/D26865

llvm-svn: 287448
2016-11-19 18:14:24 +00:00
Rui Ueyama 7ee38e00a5 Enable -threads by default.
LLD supports multi-threading, and it seems to be working well as
you can see in r287140. In short, LLD runs a few percent to 30%
faster with -threads and more than 50% faster if you are using
-build-id (your mileage may vary depending on your computer).

However, I don't think most users even don't know about that because
-threads is not a default option.

This patch enables it by default.

Discussion thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107160.html

llvm-svn: 287237
2016-11-17 17:06:51 +00:00
Rui Ueyama cb87675186 Define -build-id=tree as a synonym for -build-id=sha1.
Our build-id is a tree hash anyway, so I'll define this as a synonym
for sha1. GNU gold takes this parameter, so this is for compatibility
with that.

llvm-svn: 287119
2016-11-16 17:14:11 +00:00
Rui Ueyama 23f441d3ac Add -no-threads option that negates the effect of -threads.
llvm-svn: 287072
2016-11-16 01:39:50 +00:00
Peter Collingbourne cd513a41c1 Bitcode: Clean up error handling for certain bitcode query functions.
The functions getBitcodeTargetTriple(), isBitcodeContainingObjCCategory(),
getBitcodeProducerString() and hasGlobalValueSummary() now return errors
via their return value rather than via the diagnostic handler.

To make this work, re-implement these functions using non-member functions
so that they can be used without the LLVMContext required by BitcodeReader.

Differential Revision: https://reviews.llvm.org/D26532

llvm-svn: 286623
2016-11-11 19:50:24 +00:00
Mehdi Amini 41af43092c Make the Error class constructor protected
This is forcing to use Error::success(), which is in a wide majority
of cases a lot more readable.

Differential Revision: https://reviews.llvm.org/D26481

llvm-svn: 286561
2016-11-11 04:28:40 +00:00
Rui Ueyama 049e045c3a Handle Archive::children's error proerly.
The previous code didn't make sense at all. Now an error condition
is handled with fatal(). Thanks to Mehdi for pointing out the issue.

llvm-svn: 286547
2016-11-11 02:09:28 +00:00
George Rimar 1a33c0f242 [ELF] - Implemented --symbol-ordering-file option.
Patch allows to pass a symbols file to linker.
LLD will map symbols to sections and sort sections
in output according to symbol ordering file.

That can help to reduce the startup time and/or
amount of pagefaults during startup.

Also, interesting benchmark result was produced by Rafael Espíndola. 
After applying the symbols file for clang he timed compiling 
X86MCTargetDesc.ii to an object file.  

The page faults went from just
56,988 to 56,946 since most faults are not in the binary.
Running time went from 4.403053515 to 4.178112244. 
The speedup seems to be because of better cache
locality.

Differential revision: https://reviews.llvm.org/D26130

llvm-svn: 286440
2016-11-10 09:05:20 +00:00
Rui Ueyama 58026af7f0 Simplify parseEmulation. NFC.
llvm-svn: 286406
2016-11-09 22:32:43 +00:00
Rafael Espindola 8f9026baff Don't add null and discarded sections to the global list.
Avoids having to skip them multiple times.

llvm-svn: 286261
2016-11-08 18:23:02 +00:00