Commit Graph

35 Commits

Author SHA1 Message Date
Nico Weber 64c1734438 [lld/mac] Write -v output to stderr
This matches ld64, and it's conceivable that projects try to read
this information off stderr for that reason.

--version keeps writing to stdout.

Differential Revision: https://reviews.llvm.org/D113020
2021-11-02 13:59:14 -04:00
Fangrui Song 0db402c5b4 [lld] Buffer writes when composing a single diagnostic
llvm::errs() is unbuffered. On a POSIX platform, composing a diagnostic
string may invoke the ::write syscall multiple times, which can be slow.
Buffer writes to a temporary SmallString when composing a single diagnostic to
reduce the number of ::write syscalls to one (also easier to read under
strace/truss).

For an invocation of ld.lld with 62000+ lines of
`ld.lld: warning: symbol ordering file: no such symbol: ` warnings (D87121),
the buffering decreases the write time from 1s to 0.4s (for /dev/tty) and
from 0.4s to 0.1s (for a tmpfs file). This can speed up
`relocation R_X86_64_PC32 out of range` diagnostic printing as well
with `--noinhibit-exec --no-fatal-warnings`.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D87272
2021-09-09 09:27:14 -07:00
Alexandre Ganea 45b8a741fb [LLD][COFF] When using LLD-as-a-library, always prevent re-entrance on failures
This is a follow-up for D70378 (Cover usage of LLD as a library).

While debugging an intermittent failure on a bot, I recalled this scenario which
causes the issue:

1.When executing lld/test/ELF/invalid/symtab-sh-info.s L45, we reach
  lld:🧝:Obj-File::ObjFile() which goes straight into its base ELFFileBase(),
  then ELFFileBase::init().
2.At that point fatal() is thrown in lld/ELF/InputFiles.cpp L381, leaving a
  half-initialized ObjFile instance.
3.We then end up in lld::exitLld() and since we are running with LLD_IN_TEST, we
  hapily restore the control flow to CrashRecoveryContext::RunSafely() then back
  in lld::safeLldMain().
4.Before this patch, we called errorHandler().reset() just after, and this
  attempted to reset the associated SpecificAlloc<ObjFile<ELF64LE>>. That tried
  to free the half-initialized ObjFile instance, and more precisely its
  ObjFile::dwarf member.

Sometimes that worked, sometimes it failed and was catched by the
CrashRecoveryContext. This scenario was the reason we called
errorHandler().reset() through a CrashRecoveryContext.

But in some rare cases, the above repro somehow corrupted the heap, creating a
stack overflow. When the CrashRecoveryContext's filter (that is,
__except (ExceptionFilter(GetExceptionInformation()))) tried to handle the
exception, it crashed again since the stack was exhausted -- and that took the
whole application down. That is the issue seen on the bot. Locally it happens
about 1 times out of 15.

Now this situation can happen anywhere in LLD. Since catching stack overflows is
not a reliable scenario ATM when using CrashRecoveryContext, we're now
preventing further re-entrance when such failures occur, by signaling
lld::SafeReturn::canRunAgain=false. When running with LLD_IN_TEST=2 (or above),
only one iteration will be executed, instead of two.

Differential Revision: https://reviews.llvm.org/D88348
2020-11-12 08:14:43 -05:00
serge-sans-paille 1e70ec10eb [lld] Provide a hook to customize undefined symbols error handling
This is a follow up to https://reviews.llvm.org/D87758, implementing the missing
symbol part, as done by binutils.

Differential Revision: https://reviews.llvm.org/D89687
2020-11-09 13:28:48 +01:00
serge-sans-paille 1c068a0103 Fix 'default label in switch which covers all enumeration values' warning 2020-11-03 12:58:15 +01:00
serge-sans-paille cfc32267e2 Provide a hook to customize missing library error handling
Make it possible for lld users to provide a custom script that would help to
find missing libraries. A possible scenario could be:

    % clang /tmp/a.c -fuse-ld=lld -loauth -Wl,--error-handling-script=/tmp/addLibrary.py
    unable to find library -loauth
    looking for relevant packages to provides that library

        liboauth-0.9.7-4.el7.i686
        liboauth-devel-0.9.7-4.el7.i686
        liboauth-0.9.7-4.el7.x86_64
        liboauth-devel-0.9.7-4.el7.x86_64
        pix-1.6.1-3.el7.x86_64

Where addLibrary would be called with the missing library name as first argument
(in that case addLibrary.py oauth)

Differential Revision: https://reviews.llvm.org/D87758
2020-11-03 11:01:29 +01:00
Alexandre Ganea f2efb5742c [LLD][COFF] Cover usage of LLD-as-a-library in tests
In lit tests, we run each LLD invocation twice (LLD_IN_TEST=2), without shutting down the process in-between. This ensures a full cleanup is properly done between runs.
Only active for the COFF driver for now. Other drivers still use LLD_IN_TEST=1 which executes just one iteration with full cleanup, like before.
When the environment variable LLD_IN_TEST is unset, a shortcut is taken, only one iteration is executed, no cleanup for faster exit, like before.
A public API, lld::safeLldMain(), is also available when using LLD as a library.

Differential Revision: https://reviews.llvm.org/D70378
2020-09-24 15:07:50 -04:00
Reid Kleckner 932f0276ea [Support] Move LLD's parallel algorithm wrappers to support
Essentially takes the lld/Common/Threads.h wrappers and moves them to
the llvm/Support/Paralle.h algorithm header.

The changes are:
- Remove policy parameter, since all clients use `par`.
- Rename the methods to `parallelSort` etc to match LLVM style, since
  they are no longer C++17 pstl compatible.
- Move algorithms from llvm::parallel:: to llvm::, since they have
  "parallel" in the name and are no longer overloads of the regular
  algorithms.
- Add range overloads
- Use the sequential algorithm directly when 1 thread is requested
  (skips task grouping)
- Fix the index type of parallelForEachN to size_t. Nobody in LLVM was
  using any other parameter, and it made overload resolution hard for
  for_each_n(par, 0, foo.size(), ...) because 0 is int, not size_t.

Remove Threads.h and update LLD for that.

This is a prerequisite for parallel public symbol processing in the PDB
library, which is in LLVM.

Reviewed By: MaskRay, aganea

Differential Revision: https://reviews.llvm.org/D79390
2020-05-05 15:21:05 -07:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Andrew Ng de2dfc8b20 [LLD] Avoid exiting with a locked mutex NFC
In ErrorHandler::error(), rearrange code to avoid calling exitLld with
the mutex locked. Acquire mutex lock when flushing the output streams in
exitLld.

Differential Revision: https://reviews.llvm.org/D73281
2020-01-28 16:44:44 +00:00
Andrew Ng 564481aebe [Support] ThreadPoolExecutor fixes for Windows/MinGW
Changed ThreadPoolExecutor to no longer use detached threads and instead
to join threads on destruction. This is to prevent intermittent crashing
on Windows when doing a normal full exit, e.g. via exit().

Changed ThreadPoolExecutor to be a ManagedStatic so that it can be
stopped on llvm_shutdown(). Without this, it would only be stopped in
the destructor when doing a full exit. This is required to avoid
intermittent crashing on Windows due to a race condition between the
ThreadPoolExecutor starting up threads and the process doing a fast
exit, e.g. via _exit().

The Windows crashes appear to only occur with the MSVC static runtimes
and are more frequent with the debug static runtime.

These changes also prevent intermittent deadlocks on exit with the MinGW
runtime.

Differential Revision: https://reviews.llvm.org/D70447
2020-01-10 12:44:01 +00:00
James Y Knight d3fec7fb45 LLD: Don't use the stderrOS stream in link before it's reassigned.
Remove the lld::enableColors function, as it just obscures which
stream it's affecting, and replace with explicit calls to the stream's
enable_colors.

Also, assign the stderrOS and stdoutOS globals first in link function,
just to ensure nothing might use them.

(Either change individually fixes the issue of using the old
stream, but both together seems best.)

Follow-up to b11386f9be.

Differential Revision: https://reviews.llvm.org/D70492
2019-11-21 10:55:03 -05:00
Rui Ueyama b11386f9be Make it possible to redirect not only errs() but also outs()
This change is for those who use lld as a library. Context:
https://reviews.llvm.org/D70287

This patch adds a new parmeter to lld::*::link() so that we can pass
an raw_ostream object representing stdout. Previously, lld::*::link()
took only an stderr object.

Justification for making stdoutOS and stderrOS mandatory: I wanted to
make link() functions to take stdout and stderr in that order.
However, if we change the function signature from

  bool link(ArrayRef<const char *> args, bool canExitEarly,
            raw_ostream &stderrOS = llvm::errs());

to

  bool link(ArrayRef<const char *> args, bool canExitEarly,
            raw_ostream &stdoutOS = llvm::outs(),
            raw_ostream &stderrOS = llvm::errs());

, then the meaning of existing code that passes stderrOS silently
changes (stderrOS would be interpreted as stdoutOS). So, I chose to
make existing code not to compile, so that developers can fix their
code.

Differential Revision: https://reviews.llvm.org/D70292
2019-11-18 11:18:06 +09:00
Igor Kudrin b65016ddac [ELF] For VS-style diagnostics, prefer printing full paths in the header.
The filename part in the message header is used by Visual Studio
to fill Error List so that a user can click on an item and jump
to the mentioned location. If we use only the name of a source file
and not the full path, Visual Studio might be unable to find the right
file or, even worse, show a wrong one.

Differential Revision: https://reviews.llvm.org/D65875

llvm-svn: 368409
2019-08-09 08:29:03 +00:00
Igor Kudrin da41e2107e [ELF] Fix splitting messages for duplicate symbols.
D65213 (rL367536) does not work for the case when a source file path
includes subdirectories.

Differential Revision: https://reviews.llvm.org/D65810

llvm-svn: 368153
2019-08-07 11:32:43 +00:00
Rui Ueyama 6c5fc94093 Simplify error message output. NFC.
Differential Revision: https://reviews.llvm.org/D65855

llvm-svn: 368144
2019-08-07 10:11:24 +00:00
Rui Ueyama cac8df1ab9 Re-submit r367649: Improve raw_ostream so that you can "write" colors using operator<<
The original patch broke buildbots, perhaps because it changed the
default setting whether colors are enabled or not.

llvm-svn: 368131
2019-08-07 08:08:17 +00:00
Rui Ueyama 4d41c332ef Revert r367649: Improve raw_ostream so that you can "write" colors using operator<<
This reverts commit r367649 in an attempt to unbreak Windows bots.

llvm-svn: 367658
2019-08-02 07:22:34 +00:00
Rui Ueyama c1981b2b26 Add an assert() to catch possible regexp errors.
llvm-svn: 367651
2019-08-02 05:11:19 +00:00
Rui Ueyama 96a7a225f5 Add a comment for --vs-diagnostics.
llvm-svn: 367650
2019-08-02 05:04:27 +00:00
Rui Ueyama a52f982f1c Improve raw_ostream so that you can "write" colors using operator<<
1. raw_ostream supports ANSI colors so that you can write messages to
the termina with colors. Previously, in order to change and reset
color, you had to call `changeColor` and `resetColor` functions,
respectively.

So, if you print out "error: " in red, for example, you had to do
something like this:

  OS.changeColor(raw_ostream::RED);
  OS << "error: ";
  OS.resetColor();

With this patch, you can write the same code as follows:

  OS << raw_ostream::RED << "error: " << raw_ostream::RESET;

2. Add a boolean flag to raw_ostream so that you can disable colored
output. If you disable colors, changeColor, operator<<(Color),
resetColor and other color-related functions have no effect.

Most LLVM tools automatically prints out messages using colors, and
you can disable it by passing a flag such as `--disable-colors`.
This new flag makes it easy to write code that works that way.

Differential Revision: https://reviews.llvm.org/D65564

llvm-svn: 367649
2019-08-02 04:48:30 +00:00
Igor Kudrin 07ceadda25 [ELF] With --vs-diagnostics, print a separate message for each location of a duplicate symbol.
We extract and print the source location in the message header so that
Visual Studio is able to parse it and jump there. As duplicate symbols
are defined in several locations, it is more convenient to have separate
error messages, which allows a user to easily access all the locations.

Differential Revision: https://reviews.llvm.org/D65213

llvm-svn: 367536
2019-08-01 09:58:03 +00:00
Igor Kudrin 510086b5e5 [ELF] Fix finding locations in messages for undefined hidden symbols.
Previously, when `--vs-diagnostics` was used, the linker printed
something like

  hidden(undef.s): error: undefined hidden symbol: foo
  >>> referenced by undef.s:15

Differential Revision: https://reviews.llvm.org/D65499

llvm-svn: 367515
2019-08-01 05:23:45 +00:00
Alexander Richardson a8104b4927 [LLD] Do not print additional newlines after reaching error limit
Summary:
This could previously happen if errors that are emitted after reaching the
error limit. In that case, the flag inside the newline() function will be
set to true which causes the next call to print a newline even though the
actual message will be discarded.

Reviewers: ruiu, grimar, MaskRay, espindola

Reviewed By: ruiu

Subscribers: emaste, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65198

llvm-svn: 366944
2019-07-24 20:56:23 +00:00
Chris Jackson 87886299b4 [lld] Add Visual Studio compatible diagnostics
Summary:
Add a --vs-diagnostics flag that alters the format of diagnostic output
to enable source hyperlinks in Visual Studio.

Differential Revision: https://reviews.llvm.org/D58484

Reviewed by: ruiu

llvm-svn: 366333
2019-07-17 14:54:02 +00:00
Rui Ueyama 136d27ab4d [Coding style change][lld] Rename variables for non-ELF ports
This patch does the same thing as r365595 to other subdirectories,
which completes the naming style change for the entire lld directory.

With this, the naming style conversion is complete for lld.

Differential Revision: https://reviews.llvm.org/D64473

llvm-svn: 365730
2019-07-11 05:40:30 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Martin Storsjo 0f3d8e2360 [Common] Discard the temp file while keeping the memory mapping open, on errors
Differential Revision: https://reviews.llvm.org/D51095

llvm-svn: 340635
2018-08-24 18:36:42 +00:00
Sam Clegg b2144058a6 [LTO] Errors in LLVM backend should manifest as lld errors
Differential Revision: https://reviews.llvm.org/D48812

llvm-svn: 336143
2018-07-02 21:01:43 +00:00
Sam Clegg 3ad27e92bc Code cleanup in preparation for adding LTO for wasm. NFC.
- Move some common code into Common/rrorHandler.cpp and
  Common/Strings.h.
- Don't use `fatal` when incompatible bitcode files are
  encountered.
- Rename NameRef variable to just Name

See D47162

Differential Revision: https://reviews.llvm.org/D47206

llvm-svn: 333021
2018-05-22 20:20:25 +00:00
Sam Clegg 77c1def71a Use ErrorOS for log messages as well as error
log are also diagnostics so it seems like they should to
the same place as errors and debug messages.

Without this change when I enable --verbose those messages
go to stdout, but when I enable "-mllvm -debug" those messages
go to stderr (because dbgs() goes to stderr by default).

So I end up having to do this a lot:
 lld <args> > output_message 2>&1

Differential Revision: https://reviews.llvm.org/D41033

llvm-svn: 320427
2017-12-11 21:57:31 +00:00
Rafael Espindola a4884cc38f Try harder to delete the temporary file.
It is really hard to cover restarts in a debugger, SIGKILL or power
failures. I will try to handle them in a followup patch, but it will
not support all the systems lld has to run on.

RemoveFileOnSignal takes care of crashes.

So what is left is making sure all regular exits delete the file. This
patch does that by moving the buffer to error handling. That is a bit
of a hack, but seemed better than to generalize it to take a callback on
construction.

I will implement this on COFF on the next patch.

llvm-svn: 318060
2017-11-13 18:06:43 +00:00
Rafael Espindola 37a575f8b6 Delete dead code.
llvm-svn: 317633
2017-11-07 23:12:41 +00:00
Rui Ueyama 3fa55c5026 Instead of enclosing an entire file, add lld:: specifier for public functions.
llvm-svn: 316776
2017-10-27 18:04:49 +00:00
Bob Haarman b8a59c8aa5 [lld] unified COFF and ELF error handling on new Common/ErrorHandler
Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39259

llvm-svn: 316624
2017-10-25 22:28:38 +00:00