Commit Graph

3086 Commits

Author SHA1 Message Date
Vitaly Buka
f2a585e6d3 [NFC] Fix "not used" warning 2021-04-26 22:09:23 -07:00
Abhina Sreeskantharajan
82b3e28e83 [SystemZ][z/OS][Windows] Add new OF_TextWithCRLF flag and use this flag instead of OF_Text
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.

Solution:
This patch adds two new flags

  - OF_CRLF which indicates that CRLF translation is used.
  - OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.

Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.

So this is the behaviour per platform with my patch:

z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode

Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return

The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
  if (Flags & OF_CRLF)
    CrtOpenFlags |= _O_TEXT;
```

These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99426
2021-04-06 07:23:31 -04:00
Cyndy Ishida
0116d04d04 [TextAPI] move source code files out of subdirectory, NFC
TextAPI/ELF has moved out into InterfaceStubs, so theres no longer a
need to seperate out TextAPI between formats.

Reviewed By: ributzka, int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D99811
2021-04-05 10:24:42 -07:00
Gabriel Hjort Åkerlund
496fb70b14 [MachO] Fix enum-int mismatch warning
Change-Id: Ie637dc7761144e5552b05a9c286f1e736579823d

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D91520
2020-12-28 17:39:41 +01:00
Georgii Rymar
6487ffafd1 Reland "[yaml2obj][ELF] - Simplify the code that performs sections validation."
This reverts commit 1b589f4d4d and relands the D89463
with the fix: update `MappingTraits<FileFilter>::validate()` in ClangTidyOptions.cpp to
match the new signature (change the return type to "std::string" from "StringRef").

Original commit message:

This:

Changes the return type of MappingTraits<T>>::validate to std::string
instead of StringRef. It allows to create more complex error messages.

It introduces std::vector<std::pair<StringRef, bool>> getEntries():
a new virtual method of Section, which is the base class for all sections.
It returns names of special section specific keys (e.g. "Entries") and flags that says if them exist in a YAML.
The code in validate() uses this list of entries descriptions to generalize validation.
This approach was discussed in the D89039 thread.

Differential revision: https://reviews.llvm.org/D89463
2020-10-20 16:25:33 +03:00
Georgii Rymar
1b589f4d4d Revert "[yaml2obj][ELF] - Simplify the code that performs sections validation."
This reverts commit b9e2b59680.
2020-10-20 15:16:56 +03:00
Georgii Rymar
b9e2b59680 [yaml2obj][ELF] - Simplify the code that performs sections validation.
This:
1) Changes the return type of `MappingTraits<T>>::validate` to `std::string`
instead of `StringRef`. It allows to create more complex error messages.

2) It introduces std::vector<std::pair<StringRef, bool>> getEntries():
a new virtual method of Section, which is the base class for all sections.
It returns names of special section specific keys (e.g. "Entries") and flags that
says if them exist in a YAML. The code in validate() uses this list of entries
descriptions to generalize validation.
This approach was discussed in the D89039 thread.

Differential revision: https://reviews.llvm.org/D89463
2020-10-20 11:28:23 +03:00
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
Michele Scandale
53880b8cb9 [CMake] Make intrinsics_gen dependency unconditional.
The `intrinsics_gen` target exists in the CMake exports since r309389
(see LLVMConfig.cmake.in), hence projects can depend on `intrinsics_gen`
even it they are built separately from LLVM.

Reviewed By: MaskRay, JDevlieghere

Differential Revision: https://reviews.llvm.org/D83454
2020-07-17 16:43:17 -07:00
Nico Weber
425fb21e03 ld64.lld: Make janky support for tbd files actually work sometimes
Also fix a bug in the test input that made the test miss this issue.
2020-07-02 15:31:21 -04:00
Nemanja Ivanovic
16989f6f5c [LLD] Add required dependency after shared libs break due to ba5087f130
The dependency on TextAPI was not added and is required for shared
libs builds.
2020-07-02 12:28:17 -05:00
Nico Weber
ba5087f130 ld64.lld: Add janky support for tbd files
With this, a simple hello world links against libSystem.tbd and the
old ld64.lld linker kind of works again with newer SDKs.

The motivation here is to have an arm64 cross linker that's good
enough to be able to run simple configure link checks on non-mac
systems for generating config.h files. Once -flavor darwinnew can
link arm64, we'll switch to that.
2020-07-02 00:05:52 -04:00
Eric Christopher
058ec20677 [lld] As part of using inclusive language within the llvm
project, migrate away from the use of blacklist and whitelist.
2020-06-19 21:50:14 -07:00
Saleem Abdulrasool
9cb2badc59 lld: use std::make_unique (NFC)
The LLVM code base already uses C++14, use std::make_unique
to avoid the explicit constructor invocation via new and to avoid
spelling out the type twice.
2020-06-03 19:23:13 +00:00
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
Nico Weber
eb81d440fc fix typo in comment to cycle bots 2020-04-04 12:52:45 -04:00
Kazuaki Ishizaki
7c5fcb3591 [lld] NFC: fix trivial typos in comments
Differential Revision: https://reviews.llvm.org/D72339
2020-04-02 01:21:36 +09:00
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
Kazuaki Ishizaki
7ae3d33546 [lld] Fix trivial typos in comments
Reviewed By: ruiu, MaskRay

Differential Revision: https://reviews.llvm.org/D72196
2020-01-06 10:25:48 -08:00
Fangrui Song
681b1be774 [lld] Fix -Wrange-loop-analysis warnings
One instance looks like a false positive:

lld/ELF/Relocations.cpp:1622:14: note: use reference type 'const std::pair<ThunkSection *, uint32_t> &' (aka 'cons
t pair<lld:🧝:ThunkSection *, unsigned int> &') to prevent copying
        for (const std::pair<ThunkSection *, uint32_t> ts : isd->thunkSections)

It is not changed in this commit.
2020-01-01 15:41:20 -08:00
Igor Kudrin
5279f96577 [MachO] Fix detecting malformed DWARF.
This fixes an invalid constant used to detect the reserved range when
reading the compilation unit header. See also: D64622 and D65039.

Differential Revision: https://reviews.llvm.org/D71546
2019-12-17 15:03:23 +07:00
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
45f8ee5f3c Revert "Fix shared lib build."
This reverts commit 17e37ba57a
because it introduced a circular dependency between Core and Common.
Because d0371f4736 fixed a build issue,
we no longer need that dependency.
2019-11-19 12:05:55 +09:00
Rui Ueyama
d0371f4736 Fix component build
b11386f9be broke lld build
if `-DBUILD_SHARED_LIBS=ON` is passed to CMake.
2019-11-19 11:20:52 +09:00
Michael Liao
17e37ba57a Fix shared lib build. 2019-11-18 13:08:51 -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
Reid Kleckner
90c64a3456 Move endian constant from Host.h to SwapByteOrder.h, prune include
Works on this dependency chain:
  ArrayRef.h ->
  Hashing.h -> --CUT--
  Host.h ->
  StringMap.h / StringRef.h

ArrayRef is very popular, but Host.h is rarely needed. Move the
IsBigEndianHost constant to SwapByteOrder.h. Clients of that header are
more likely to need it.

llvm-svn: 375316
2019-10-19 00:48:11 +00:00
Matt Davis
4d17cdc704 [lld][mach-o] Avoid segfaulting when handling an empty section list.
Summary:
The following patch avoids segfaulting if the section list is empty when writing a mach-o MH_OBJECT.  I ran into this case from a more complicated example trying to dead_strip while using '-r' in lld.

I'm not sure if having empty sections is a legal mach-o, but it does seem that other llvm-binutils tools can ingest such a boring object with out issue.  Would it be better to emit an error, emit a warning, or do nothing?  It seems that adding a warning diagnostic might be helpful to users, as I did not expect to have a section-less object when the linker was done.

Reviewers: kledzik, ruiu

Subscribers: llvm-commits, jrm

Tags: #lld, #llvm

Differential Revision: https://reviews.llvm.org/D67735

llvm-svn: 372995
2019-09-26 17:03:20 +00:00
Rui Ueyama
91864f82c7 [mach-o] Extend LC_DATA_IN_CODE support to x86_64
Patch by LemonBoy

Differential Revision: https://reviews.llvm.org/D62185

llvm-svn: 370183
2019-08-28 10:11:50 +00:00
Jonas Devlieghere
6ba7992031 [LLD] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

Differential revision: https://reviews.llvm.org/D66259

llvm-svn: 368936
2019-08-14 22:28:17 +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
Igor Kudrin
5978c9249b [MachO] Update LLD to use 64-bit offsets with DataExtractor (3/5)
Differential Revision: https://reviews.llvm.org/D65639

llvm-svn: 368032
2019-08-06 13:37:34 +00:00
Fangrui Song
d9b948b6eb Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC
F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800
2019-08-05 05:43:48 +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
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
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
Fangrui Song
32c0ebe615 Use llvm::stable_sort
Make some small adjustment while touching the code: make parameters
const, use less_first(), etc.

Differential Revision: https://reviews.llvm.org/D60989

llvm-svn: 358943
2019-04-23 02:42:06 +00:00
Rui Ueyama
7f8ca6e367 lld: Fix initial Mach-O load commands size calculation omitting LC_FUNCTION_STARTS
Patch by Nicholas Allegra.

The Mach-O writer calculates the size of load commands multiple times.

First, Util::assignAddressesToSections() (in MachONormalizedFileFromAtoms.cpp)
calculates the size using headerAndLoadCommandsSize() (in
MachONormalizedFileBinaryWriter.cpp), which creates a temporary
MachOFileLayout for the NormalizedFile, only to retrieve its
headerAndLoadCommandsSize.  Later, writeBinary() (in
MachONormalizedFileBinaryWriter.cpp) creates a new layout and uses the offsets
from that layout to actually write out everything in the NormalizedFile.

But the NormalizedFile changes between the first computation and the second.
When Util::assignAddressesToSections is called, file.functionStarts is always
empty because Util::addFunctionStarts has not yet been called. Yet
MachOFileLayout decides whether to include a LC_FUNCTION_STARTS command based
on whether file.functionStarts is nonempty. Therefore, the initial computation
always omits it.

Because padding for the __TEXT segment (to make its size a multiple of the
page size) is added between the load commands and the first section, LLD still
generates a valid binary as long as the amount of padding happens to be large
enough to fit LC_FUNCTION_STARTS command, which it usually is.

However, it's easy to reproduce the issue by adding a section of a precise
size. Given foo.c:

  __attribute__((section("__TEXT,__foo")))
  char foo[0xd78] = {0};

Run:

  clang -dynamiclib -o foo.dylib foo.c -fuse-ld=lld -install_name
  /usr/lib/foo.dylib
  otool -lvv foo.dylib

This should produce:

  truncated or malformed object (offset field of section 1 in LC_SEGMENT_64
  command 0 not past the headers of the file)

This commit:

 - Changes MachOFileLayout to always assume LC_FUNCTION_STARTS is present for
   the initial computation, as long as generating LC_FUNCTION_STARTS is
   enabled. It would be slightly better to check whether there are actually
   any functions, since no LC_FUNCTION_STARTS will be generated if not, but it
   doesn't cause a problem if the initial computation is too high.

 - Adds a test.

 - Adds an assert in MachOFileLayout::writeSectionContent() that we are not
   writing section content into the load commands region (which would happen
   if the offset was calculated too low due to the initial load commands size
   calculation being too low).  Adds an assert in
   MachOFileLayout::writeLoadCommands to validate a similar situation where
   two size-of-load-commands computations are expected to be equivalent.

llvm-svn: 358545
2019-04-17 01:47:16 +00:00
Fangrui Song
8048fe2b8c [ELF][MachO][wasm] Simplify range-style std::find{,_if} with STLExtras.h utilities. NFC
llvm-svn: 357269
2019-03-29 16:21:16 +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
Reid Kleckner
4dc0b1ac60 Fix clang -Wimplicit-fallthrough warnings across llvm, NFC
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
   of only 'break'.

We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
   doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
   the outer case.

I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.

Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu

Differential Revision: https://reviews.llvm.org/D53950

llvm-svn: 345882
2018-11-01 19:54:45 +00:00
Rui Ueyama
9ae88c64fa Eliminate dependency to formatv(). NFC.
llvm-svn: 344177
2018-10-10 20:29:29 +00:00
Fangrui Song
2043a58abe Adapt OptTable::PrintHelp change in D51009
Summary: Before, OptTable::PrintHelp append "[options] <inputs>" to its parameter `Help`. It is more flexible to change its semantic to `Usage` and let user customize the usage line.

Reviewers: rupprecht, ruiu, espindola

Reviewed By: rupprecht

Subscribers: emaste, sbc100, arichardson, aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D53054

llvm-svn: 344099
2018-10-10 00:15:36 +00:00
Tom Stellard
a6749135df MachO: Change getString16() back to inline function
This was accidentally changed in r341670.

llvm-svn: 341672
2018-09-07 15:51:52 +00:00
Tom Stellard
493f3bad3c MachO: Fix out-of-bounds memory access in getString16
Summary:
This fixes the following tests when gcc is compiled with gcc8:

lld :: mach-o/do-not-emit-unwind-fde-arm64.yaml
lld :: mach-o/eh-frame-relocs-arm64.yaml

llvm.org/PR38096

Reviewers: lhames, kledzik, javed.absar

Subscribers: kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D51547

llvm-svn: 341670
2018-09-07 15:42:01 +00:00
Rui Ueyama
41831204c7 Rename a function to follow the LLVM coding style.
llvm-svn: 340716
2018-08-27 06:18:10 +00:00
Nico Weber
386bf1216e win: Omit ".exe" from lld warning and error messages.
This is a minor follow-up to https://reviews.llvm.org/D49189. On Windows, lld
used to print "lld-link.exe: error: ...". Now it just prints "lld-link: error:
...". This matches what link.exe does (it prints "LINK : ...") and makes lld's
output less dependent on the host system.

https://reviews.llvm.org/D51133

llvm-svn: 340487
2018-08-22 23:52:13 +00:00
Nico Weber
bbfe0b79e2 Omit path to lld binary from lld's error, warning, and log output.
lld currently prepends the absolute path to itself to every diagnostic it
emits. This path can be longer than the diagnostic, and makes the actual error
message hard to read.

There isn't a good reason for printing this path: if you want to know which lld
you're running, pass -v to clang – chances are that if you're unsure of this,
you're not only unsure when it errors out. Some people want an indication that
the diagnostic is from the linker though, so instead print just the basename of
the linker's path.

Before:

```
$ out/bin/clang -target x86_64-unknown-linux -x c++ /dev/null -fuse-ld=lld 
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crt1.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crti.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtbegin.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc_s
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: unable to find library -lgcc_s
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtend.o: No such file or directory
/Users/thakis/src/llvm-mono/out/bin/ld.lld: error: cannot open crtn.o: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```

After:

```
$ out/bin/clang -target x86_64-unknown-linux -x c++ /dev/null -fuse-ld=lld 
ld.lld: error: cannot open crt1.o: No such file or directory
ld.lld: error: cannot open crti.o: No such file or directory
ld.lld: error: cannot open crtbegin.o: No such file or directory
ld.lld: error: unable to find library -lgcc
ld.lld: error: unable to find library -lgcc_s
ld.lld: error: unable to find library -lc
ld.lld: error: unable to find library -lgcc
ld.lld: error: unable to find library -lgcc_s
ld.lld: error: cannot open crtend.o: No such file or directory
ld.lld: error: cannot open crtn.o: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```

https://reviews.llvm.org/D49189

llvm-svn: 337634
2018-07-20 23:09:12 +00:00
Brian Gesiak
4fcebf6cf6 [Darwin] Do not error on '-lto_library' option
Summary:
Any invocation of `clang -fuse-ld=lld` that results in a link command
on a macOS host currently fails, because the Darwin lld driver does not
recognize the `-lto_library` option that Clang passes it. Fix the error
by having the Darwin driver ignore the option.

The Clang driver's macOS toolchain is written such that it will always
pass the `-lto_library` option to the linker invocation on a macOS host.
And although the DarwinLdDriver is written to ignore any unknown arguments,
because `-lto_library` begins with `-l`, the DarwinLdDriver interprets it
as a library search command, for a library named "to_library". When the
DarwinLdDriver is unable to find a library specified via `-l`, it exits
with a hard error. This causes any invocation of `clang -fuse-ld=lld`
that results in a link command on a macOS host to fail with an error.

To fix the issue, I considered two alternatives:

1. Modify the Clang Darwin toolchain to only pass `-lto_library` if lld
   is *not* being used. lld doesn't support LTO on Darwin anyway, so it
   can't use the option. However, I opted against this because, if and
   when lld *does* support LTO on Darwin, I'll have to make another
   commit to Clang in order to get it to pass the option to lld again.
2. Modify the Darwin lld driver to ignore the `-lto_library` option.
   Just in case users may take this to mean LTO is supported, I also
   added a warning. If and when lld supports LTO on Darwin, the same
   commit that adds support for this option can remove the warning.

Option (2) seemed better to me, and is the rationale behind this commit.

Test Plan: check-lld

Reviewers: ruiu, smeenai, pcc

Reviewed By: smeenai

Subscribers: JDevlieghere, pcc, mehdi_amini, inglorion, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D47994

llvm-svn: 334641
2018-06-13 18:59:14 +00:00
Sam Clegg
724c217393 Fix -DBUILD_SHARED_LIBS=1 build
This was broken in rL334466

llvm-svn: 334507
2018-06-12 14:51:18 +00:00