Commit Graph

38 Commits

Author SHA1 Message Date
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
Brian Gesiak b9f7f4b87c [Darwin] Use errorHandler from liblldCommon
Summary:
Error handling in liblldCore and the Darwin toolchain prints to an
output stream. A TODO in the project explained that a diagnostics
interface resembling Clang's should be added.

For now, the simple diagnostics interface defined in liblldCommon seems
like an improvement. It prints colors when they're available, uses locks
for thread-safety, and abstracts away the `"error: "` and newline
literal strings that litter the Darwin toolchain code.

To use the liblldCommon error handler, a link dependency is added to
the liblldDriver library.

Test Plan:
1. check-lld
2. Invoke `ld64.lld -r` in a terminal that supports color output.
   Confirm that "ld64.lld: error: -arch not specified and could not be inferred"
   is output, and that the "error:" is colored red!

Reviewers: ruiu, smeenai

Reviewed By: ruiu

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D47998

llvm-svn: 334466
2018-06-12 02:34:04 +00:00
Pete Cooper 9b28a4559e Add cmdline options for LC_DATA_IN_CODE load command.
Also added the defaults for whether to generate this load command, which
the cmdline options are able to override.

There was also a difference to ld64 which is fixed here in that ld64 will
generate an empty data in code command if requested.

rdar://problem/24472630

llvm-svn: 260191
2016-02-09 02:10:39 +00:00
Pete Cooper 41f3e8e408 Generate LC_FUNCTION_STARTS load command.
This load command generates data in the LINKEDIT section which
is a list of ULEB128 delta's to all of the functions in the __text section.

It is then 0 terminated and pointer aligned to pad.

ld64 exposes the -function-starts and no-function-starts cmdline options
to override behaviour from the defaults based on file types.

rdar://problem/24472630

llvm-svn: 260188
2016-02-09 01:38:13 +00:00
Pete Cooper 40576fa0e9 Add support for the source_version cmdline option.
This is of the form A.B.C.D.E and to match ld64's behaviour, is
always output to files, even when the version is 0.

rdar://problem/24472630

llvm-svn: 259746
2016-02-04 02:45:23 +00:00
Pete Cooper 451ec4b68e Add support for -sdk_version cmdline option.
This option is emitted in the min_version load commands.

Note, there's currently a difference in behaviour compared to ld64 in
that we emit a warning if we generate a min_version load command and
didn't give an sdk_version.  We need to decide what the correct behaviour
is here as its possible we want to emit an error and force clients to
provide the option.

llvm-svn: 259729
2016-02-03 23:39:05 +00:00
Pete Cooper 354809e139 Add generation of LC_VERSION_MIN load commands.
If the command line contains something like -macosx_version_min and we
don't explicitly disable generation with -no_version_load_command then
we generate the LC_VERSION_MIN command in the output file.

There's a couple of FIXME's in here.  These will be handled soon with
more tests but I didn't want to grow this patch any more than it already was.

rdar://problem/24472630

llvm-svn: 259718
2016-02-03 22:28:29 +00:00
Pete Cooper c2bad09cdd Add command line option to disable ObjC category merging.
This adds the no_objc_category_merging cmdline option which will
be used in an upcoming commit to disable the category optimizer.

It is on by default in ld64 so we match that here.

Test case will come soon with the patch to make use of this option.

llvm-svn: 259439
2016-02-01 23:56:23 +00:00
Pete Cooper 351164504a Add support for export_dynamic cmdline option and behaviour.
This option matches the behaviour of ld64, that is it prevents globals
from being dead stripped in executables and dylibs.

Reviewed by Lang Hames

Differential Revision: http://reviews.llvm.org/D16026

llvm-svn: 258554
2016-01-22 21:13:24 +00:00
Pete Cooper 2735783090 Add the GC commandline options and throw errors if they are used
llvm-svn: 257907
2016-01-15 17:39:02 +00:00
Lang Hames b1b67f4daf [lld][Darwin] Add support for the -sectcreate option.
llvm-svn: 251183
2015-10-24 08:20:51 +00:00
Lang Hames 5c692009bc [lld][MachO] Initial implementation of -flat_namespace and -undefined.
This is a basic initial implementation of the -flat_namespace and
-undefined options for LLD-darwin. It ignores several subtlties,
but the result is close enough that we can now link LLVM (but not
clang) on Darwin and pass all regression tests.

llvm-svn: 248732
2015-09-28 20:25:14 +00:00
Lang Hames 65a64c9c29 [LLD] Add support for the -stack_size option to Darwin ld.
llvm-svn: 237841
2015-05-20 22:10:50 +00:00
Jean-Daniel Dupas 23dd15e26d [macho] -rpath support
Summary:
Work on adding -rpath support to the mach-o linker.
This patch is based on the ld64 behavior for the command line option validation.

It includes a basic test to check that the LC_RPATH load commands are properly generated when that option is used.

It also add LC_RPATH support to the binary reader, but I don't know how to test it though.


Reviewers: kledzik

Subscribers: llvm-commits

Projects: #lld

Differential Revision: http://reviews.llvm.org/D6724

llvm-svn: 224544
2014-12-18 21:33:38 +00:00
Nick Kledzik 82d24bc932 [mach-o] Add support for -order_file option
The darwin linker lets you rearrange functions and data for better locality
(less paging).  You do this with the -order_file option which supplies a text
file containing one symbol per line.

Implementing this required a small change to LayoutPass to add a custom sorter
hook.

llvm-svn: 221545
2014-11-07 21:01:21 +00:00
Nick Kledzik 24f504001d [mach-o] Add support for -force_load option
The darwin linker has two ways to force all members of an archive to be loaded.
The -all_load option applies to all static libraries.  The -force_load takes
a path to a library and just that library's members are force loaded.

llvm-svn: 221477
2014-11-06 19:33:57 +00:00
Nick Kledzik 8f75da0db3 [mach-o] Add support for -S option
The darwin linker does not process dwarf debug info.  Instead it produces a
"debug map" in the output file which points back to the original .o files for
anything that wants debug info (e.g. debugger).

The -S option means "don't add a debug map".  lld for mach-o currently does
not generate the debug map, so there is nothing to do when this option is used.
But we need to process the option to get existing projects building.

llvm-svn: 221432
2014-11-06 03:03:42 +00:00
Nick Kledzik 5172067391 [mach-o] Add support for upward linking
To deal with cycles in shared library dependencies, the darwin linker supports
marking specific link dependencies as "upward".  An upward link is when a
lower level library links against a higher level library.

llvm-svn: 219949
2014-10-16 19:31:28 +00:00
Nick Kledzik 15eba696f6 [mach-o] add -iphoneos_version_min as alias for -ios_version_min
llvm-svn: 219041
2014-10-04 00:19:56 +00:00
Nick Kledzik 09d00bb4d7 [mach-o] Add support for -dependency_info command line option
This option is added by Xcode when it runs the linker.  It produces a binary
file which contains the file the linker used.  Xcode uses the info to
dynamically update it dependency tracking.

To check the content of the binary file, the test case uses a python script
to dump the binary file as text which FileCheck can check.

llvm-svn: 219039
2014-10-04 00:16:13 +00:00
Nick Kledzik be43d7ef29 [mach-o] Implement -demangle.
The darwin linker has the -demangle option which directs it to demangle C++
(and soon Swift) mangled symbol names. Long term we need some Diagnostics object
for formatting errors and warnings. But for now we have the Core linker just
writing messages to llvm::errs(). So, to enable demangling, I changed the
Resolver to call a LinkingContext method on the symbol name.

To make this more interesting, the demangling code is done via __cxa_demangle()
which is part of the C++ ABI, which is only supported on some platforms, so I
had to conditionalize the code with the config generated HAVE_CXXABI_H.

llvm-svn: 218718
2014-09-30 23:15:39 +00:00
Tim Northover 7b33f21f3d [mach-o]: Support deprecated -seg1addr alias for -image_base
Because NO LINKER MAY CHANGE. EVER. Even if it's a complete rewrite
from scratch.

llvm-svn: 217572
2014-09-11 07:56:20 +00:00
Tim Northover af3075b93f [mach-o]: implement -image_base option on Darwin.
As suggested by Nick, this will make __unwind_info implementation more natural,
and it'd have to be done at some point anyway.

llvm-svn: 217486
2014-09-10 10:39:57 +00:00
Nick Kledzik b7035ae367 [mach-o] Add support for -pie and -no_pie
There is a bit (MH_PIE) in the flags field of the mach_header which tells
the kernel is a program was built position independent (for ASLR).  The linker
automatically attempts to build programs PIE if they are built for a recent
OS version.  But the -pie and -no_pie options override that default behavior.

llvm-svn: 217408
2014-09-09 00:17:52 +00:00
Nick Kledzik e484075d82 [mach-o] Add support for -single_module and -multi_module
These are both obsolete options that controled how dylibs were built.

llvm-svn: 216205
2014-08-21 18:57:42 +00:00
Nick Kledzik 8c0bf75ef5 [mach-o] Add support for -exported_symbols_list and -keep_private_externs
Both options control the final scope of atoms.

When -exported_symbols_list <file> is used, the file is parsed into one
symbol per line in the file.  Only those symbols will be exported (global)
in the final linked image.

The -keep_private_externs option is only used with -r mode. Normally, -r
mode reduces private extern (scopeLinkageUnit) symbols to non-external. But
add the -keep_private_externs option keeps them private external.

llvm-svn: 216146
2014-08-21 01:59:11 +00:00
Nick Kledzik 0cc040780e [mach-o] improve darwin driver 'usage' message when run with no args
llvm-svn: 215781
2014-08-15 22:42:46 +00:00
Nick Kledzik 94174f755c [mach-o] Support -filelist option in darwin driver
The darwin linker has an option, heavily used by Xcode, in which, instead
of listing all input files on the command line, the input file paths are
written to a text file and the path of that text file is passed to the linker
with the -filelist option (similar to @file).

In order to make test cases for this, I generalized the -test_libresolution
option to become -test_file_usage.

llvm-svn: 215762
2014-08-15 19:53:41 +00:00
Nick Kledzik 2d835dad0a [mach-o] Support -F and -framework options in darwin driver
Darwin has a packaging mechanism for shared libraries and headers called
frameworks.  A directory Foo.framework contains a shared library binary file
"Foo" and a subdirectory "Headers". Most OS frameworks are all in one
directory /System/Library/Frameworks/.  As a linking convenience, the linker
option "-framework Foo" means search the framework directories specified
with -F (analogous to -L) looking for a shared library Foo.framework/Foo.

llvm-svn: 215680
2014-08-14 22:20:41 +00:00
Nick Kledzik 8fc67fba01 [mach-o] Support re-exported dylibs
In general two-level namespace means each program records exactly which dylib
each undefined (imported) symbol comes from.  But, sometimes the implementor
wants to hide the implementation dylib.  For instance libSytem.dylib is the base
dylib all Darwin programs must link with.  A few years ago it was split up
into two dozen dylibs by all are hidden behind libSystem.dylib which re-exports
each sub-dylib.  All clients still think libSystem.dylib is the implementor.

To support this, the linker must load "indirect" dylibs and not just the
"direct" dylibs specified on the command line.  This is done in the
createImplicitFiles() method after all command line specified files are
loaded.  Since an indirect dylib may have already been loaded as a direct dylib
(or indirectly via a previous direct dylib), the MachOLinkingContext keeps
a list of all loaded dylibs.

With this change hello world can now be linked against the real OS or SDK.

llvm-svn: 215605
2014-08-13 23:55:41 +00:00
Nick Kledzik 0f4fbf17f5 [mach-o] wire up -t option
llvm-svn: 214414
2014-07-31 18:19:03 +00:00
Nick Kledzik 2fcbe822c0 [mach-o] Add support for -sectalign option
The -sectalign option is used to increase the alignment required for a section.
It required some reworking of how the __TEXT segment is laid out because that
segment also contains the mach_header and load commands. And the size of load
commands depend on the number of segments, sections, and dependent dylibs used.

Using this option will simplify some future test cases because the final
address of code can be pinned down, making tests of its content easier.

llvm-svn: 214268
2014-07-30 00:58:06 +00:00
Tim Northover 73c532e8a9 [mach-o]: support -Z option to skip standard library paths
llvm-svn: 212713
2014-07-10 11:46:13 +00:00
Tim Northover 18af0573df [mach-o]: support user-specified (-L) library search paths
llvm-svn: 212712
2014-07-10 11:46:08 +00:00
Tim Northover 77d82202d1 [mach-o]: support -syslibroot and -l options
These behave slightly idiosyncratically in the best of cases, and have
additional hacks layered on top of that for compatibility with badly behaved
build systems (via ld64).

For -lXYZ:
  + If XYZ is actually XY.o then search all library paths for XY.o
  + Otherwise search all library paths, first for libXYZ.dylib, then libXYZ.a
  + By default the library paths are /usr/lib and /usr/local/lib in that order.

For -syslibroot:
  + -syslibroot options apply to absolute paths in the search order.
  + All -syslibroot prefixes that exist are added to the search path *instead*
    of the original.
  + If no -syslibroot prefixed path exists, the original is kept.
  + Hacks^WExceptions:
      + If only 1 -syslibroot is given and doesn't contain /usr/lib or
        /usr/local/lib, that path is dropped entirely. (rdar://problem/6438270).
      + If the last -syslibroot is "/", all of them are ignored entirely.
        (rdar://problem/5829579).

At least, that's my best interpretation of what ld64 does in buildSearchPaths.

llvm-svn: 212706
2014-07-10 11:21:06 +00:00
Nick Kledzik 0224e3475d Add -print_atoms options to DarwinLdDriver which dumps final state of all atoms in yaml
llvm-svn: 208813
2014-05-14 21:32:21 +00:00
Nick Kledzik e773e327d3 Support darwin linker options:
-current_version, -compatibility_version, and -install_name.

Patch by Joe Ranieri

llvm-svn: 190452
2013-09-10 23:55:14 +00:00
Rui Ueyama 8ccf6da056 Rename *Options.td -> <flavor>Options.td.
Before this patch, name of driver implementation is not consistent with its
option table file. Specifically, LDOptions has a different prefix than
GnuLdDriver.

This patch renames option files, so that the option files have the same prefix
as the corresponding driver files.

Differential Revision: http://llvm-reviews.chandlerc.com/D1591

llvm-svn: 189895
2013-09-04 00:24:35 +00:00