337 Commits

Author SHA1 Message Date
Jez Ng
544148ae70 [lld-macho] -weak_{library,framework} should always take priority
We were not setting forceWeakImport for file paths given by
`-weak_library` if we had already loaded the file. This diff fixes that
by having `loadDylib` return a cached DylibFile instance even if we have
already loaded that file.

We still avoid emitting multiple LC_LOAD_DYLIBs, but we achieve this by
making inputFiles a SetVector instead of relying on the `loadedDylibs`
cache.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D93255
2020-12-15 15:58:26 -05:00
Nico Weber
d058b69b1c [lld/mac] implement -compatibility_version, -current_version
Differential Revision: https://reviews.llvm.org/D93237
2020-12-14 18:41:36 -05:00
Jez Ng
76c36c11a9 [lld-macho] Don't load dylibs more than once
Also remove `DylibFile::reexported` since it's unused.

Fixes llvm.org/PR48393.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D93001
2020-12-10 15:57:52 -08:00
Jez Ng
6a348f6158 [lld-macho] Implement -no_implicit_dylibs
Dylibs that are "public" -- i.e. top-level system libraries -- are considered
implicitly linked when another library re-exports them. That is, we should load
them & bind directly to their symbols instead of via their re-exporting
umbrella library. This diff implements that behavior by default, as well as an
opt-out flag.

In theory, this is just a performance optimization, but in practice it seems
that it's needed for correctness.

Fixes llvm.org/PR48395.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D93000
2020-12-10 15:57:52 -08:00
Jez Ng
74d799926e [lld-macho] Initialize AsmParsers earlier
We need to initialize AsmParsers before any calls to `addFile`, as
bitcode files may require them. Otherwise we trigger `Assertion T &&
T->hasMCAsmParser()' failed`.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D92913
2020-12-10 15:57:52 -08:00
Jez Ng
29d3b0e471 [lld-macho] Add support for -mcpu, -mattr, -code-model in LTO
`-mcpu` and `-code-model` tests were copied from similar ones in
LLD-ELF.

There doesn't seem to be an equivalent test for `-mattr` in LLD-ELF, so
I've verified our behavior by cribbing a test from
CodeGen/X86/recip-fastmath.ll.

Reviewed By: #lld-macho, compnerd, MaskRay

Differential Revision: https://reviews.llvm.org/D92912
2020-12-10 15:57:51 -08:00
Jez Ng
95831a56d0 [lld-macho] Implement -object_path_lto
This makes it possible for STABS entries to reference the debug info
contained in the LTO-compiled output.

I'm not sure how to test the file mtime within llvm-lit -- GNU and BSD
`stat` take different command-line arguments. I've omitted the check for
now.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D92537
2020-12-10 15:57:51 -08:00
Nico Weber
16b1f6e385 [mac/lld] Add support for the LC_LINKER_OPTION load command in o files
clang puts `-framework CoreFoundation` in this load command for files
that use @available / __builtin_available. Without support for this,
binaries that don't explicitly link to CoreFoundation fail to link.

Differential Revision: https://reviews.llvm.org/D92624
2020-12-04 08:46:53 -05:00
Nico Weber
7cb0a373d1 [mac/lld] Implement -t
Goes well with `-why_load` to get an idea of load order.

Differential Revision: https://reviews.llvm.org/D92583
2020-12-03 16:02:38 -05:00
Nico Weber
3422f3cc6e Reland "[mac/lld] Implement -why_load".
The problem was that `sym` became replaced in the call
to make<ObjFile> and referring to it afer that read memory that now
stored a different kind of symbol (a Defined instead of a LazySymbol).
Since this happens only once per archive, just copy the symbol to the
stack before make<ObjFile> and read the copy instead.

Originally reviewed at https://reviews.llvm.org/D92496
2020-12-03 08:35:12 -05:00
Nico Weber
ea0029f55d Revert "[mac/lld] Implement -why_load"
This reverts commit 542d3b609dbe99a30759942271398890fc7770dc.
Seems to break check-lld. Reverting while I take a look.
2020-12-02 18:57:46 -05:00
Nico Weber
542d3b609d [mac/lld] Implement -why_load
This is useful for debugging why lld loads .o files it shouldn't load.
It's also useful for users of lld -- I've used ld64's version of this a
few times.

Differential Revision: https://reviews.llvm.org/D92496
2020-12-02 18:33:12 -05:00
Nico Weber
ca634393fc [mac/lld] Make --reproduce work with thin archives
See http://reviews.llvm.org/rL268229 and
http://reviews.llvm.org/rL313832 which did the same for the ELF port.

Differential Revision: https://reviews.llvm.org/D92456
2020-12-02 09:48:31 -05:00
Nico Weber
b2f00f24a3 [mac/lld] Include archive name in diagnostics
Also, for .o files, include full path as given on link command line.

Before:
    lld: error: undefined symbol [...], referenced from sandbox_logging.o

After:
    lld: error: undefined symbol [...], referenced from libseatbelt.a(sandbox_logging.o)

Move archiveName up to InputFile so we can consistently use toString()
to print InputFiles in diags, and pass it to the ObjFile ctor. This
matches the ELF and COFF ports.

Differential Revision: https://reviews.llvm.org/D92437
2020-12-01 23:00:25 -05:00
Nico Weber
07ab597bb0 [lld/mac] Fix issues around thin archives
- most importantly, fix a use-after-free when using thin archives,
  by putting the archive unique_ptr to the arena allocator. This
  ports D65565 to MachO

- correctly demangle symbol namess from archives in diagnostics

- add a test for thin archives -- it finds this UaF, but only when
  running it under asan (it also finds the demangling fix)

- make forceLoadArchive() use addFile() with a bool to have the archive
  loading code in fewer places. no behavior change; matches COFF port a
  bit better

Differential Revision: https://reviews.llvm.org/D92360
2020-12-01 18:48:29 -05:00
Jez Ng
b768d57b36 [lld-macho] Add archive name and file modtime to STABS output
We should also set the modtime when running LTO. That will be done in a
future diff, together with support for the `-object_path_lto` flag.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D91318
2020-12-01 15:05:21 -08:00
Jez Ng
6b3eecd22a [lld-macho] Extend PIE option handling
* Enable PIE by default if targeting 10.6 or above on x86-64. (The
  manpage says 10.7, but that actually applies only to i386, and in
  general varies based on the target platform. I didn't update the
  manpage because listing all the different behaviors would make for a
  pretty long description.)
* Add support for `-no_pie`
* Remove `HelpHidden` from `-pie`

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D92362
2020-12-01 14:35:51 -08:00
Nico Weber
ebac710009 [lld-macho] Don't warn on non-existent system libraries
Now, new mach-o lld no longer warns if the isysroot has just
usr/lib and System/Library/Frameworks but is missing usr/local/lib
and System/Frameworks.

This matches ld64 and old mach-o lld and fixes a regression from D85992.

It also fixes the only test failure in `check-lld` when running it
on an M1 Mac.

Differential Revision: https://reviews.llvm.org/D91891
2020-11-30 16:07:20 -05:00
Nico Weber
83e60f5a55 [lld/mac] Add --reproduce option
This adds support for ld.lld's --reproduce / lld-link's /reproduce:
flag to the MachO port. This flag can be added to a link command
to make the link write a tar file containing all inputs to the link
and a response file containing the link command. This can be used
to reproduce the link on another machine, which is useful for sharing
bug report inputs or performance test loads.

Since the linker is usually called through the clang driver and
adding linker flags can be a bit cumbersome, setting the env var
`LLD_REPRODUCE=foo.tar` triggers the feature as well.

The file response.txt in the archive can be used with
`ld64.lld.darwinnew $(cat response.txt)` as long as the contents are
smaller than the command-line limit, or with `ld64.lld.darwinnew
@response.txt` once D92149 is in.

The support in this patch is sufficient to create a tar file for
Chromium's base_unittests that can link after unpacking on a different
machine.

Differential Revision: https://reviews.llvm.org/D92274
2020-11-30 08:40:21 -05:00
Nico Weber
e16c0a9a68 clang+lld: Improve clang+ld.darwinnew.lld interaction, pass -demangle
This patch:
- adds an ld64.lld.darwinnew symlink for lld, to go with f2710d4b576,
  so that `clang -fuse-ld=lld.darwinnew` can be used to test new
  Mach-O lld while it's in bring-up. (The expectation is that we'll
  remove this again once new Mach-O lld is the defauld and only Mach-O
  lld.)
- lets the clang driver know if the linker is lld (currently
  only triggered if `-fuse-ld=lld` or `-fuse-ld=lld.darwinnew` is
  passed). Currently only used for the next point, but could be used
  to implement other features that need close coordination between
  compiler and linker, e.g. having a diag for calling `clang++` instead
  of `clang` when link errors are caused by a missing C++ stdlib.
- lets the clang driver pass `-demangle` to Mach-O lld (both old and
  new), in addition to ld64
- implements -demangle for new Mach-O lld
- changes demangleItanium() to accept _Z, __Z, ___Z, ____Z prefixes
  (and updates one test added in D68014). Mach-O has an extra
  underscore for symbols, and the three (or, on Mach-O, four)
  underscores are used for block names.

Differential Revision: https://reviews.llvm.org/D91884
2020-11-24 08:51:58 -05:00
Nico Weber
c519bc7e16 lld/MachO: Move MachOOptTable to DriverUtils.cpp, remove DriverUtils.h
This makes lld/MachO look more like lld/COFF and lld/ELF, as discussed
in D91640.
2020-11-18 12:33:15 -05:00
Nico Weber
baa2aa28f5 lld: Add --color-diagnostic to MachO port, harmonize others
This adds `--[no-]color-diagnostics[=auto,never,always]` to
the MachO port and harmonizes the flag in the other ports:
- Consistently use MetaVarName
- Consistently document the non-eq version as alias of the eq version
- Use B<> in the ports that have it (no-op, shorter)
- Fix oversight in COFF port that made the --no flag have the wrong
  prefix

Differential Revision: https://reviews.llvm.org/D91640
2020-11-17 12:58:30 -05:00
Jez Ng
21f831134c [lld-macho] Add very basic support for LTO
Just enough to consume some bitcode files and link them. There's more
to be done around the symbol resolution API and the LTO config, but I don't yet
understand what all the various LTO settings do...

Reviewed By: #lld-macho, compnerd, smeenai, MaskRay

Differential Revision: https://reviews.llvm.org/D90663
2020-11-10 12:19:28 -08:00
Jez Ng
2e8e1bdb89 [lld-macho] Support linking against stub dylibs
Stub dylibs differ from "real" dylibs in that they lack any content in
their sections. What they do have are export tries and symbol tables,
which means we can still link against them. I am unclear how to
properly create these stub dylibs; XCode 11.3's `lipo` is able to create
stub dylibs, but those lack LC_ID_DYLIB load commands and are considered
invalid by most tooling. Newer versions of `lipo` aren't able to create
stub dylibs at all.  However, recent SDKs in XCode still come with valid
stub dylibs, so it still seems worthwhile to support them. The YAML in
this diff's test was generated by taking a non-stub dylib and editing
the appropriate fields.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D89012
2020-11-10 12:19:27 -08:00
Fangrui Song
20e9c36c01 Internalize functions from various tools. NFC
And internalize some classes if I noticed them:)
2020-09-26 15:57:13 -07:00
Jez Ng
c7c9776f77 [lld-macho] Allow the entry symbol to be dynamically bound
Apparently this is used in real programs. I've handled this by reusing
the logic we already have for branch (function call) relocations.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D87852
2020-09-25 11:28:33 -07:00
Jez Ng
f23f512691 [lld-macho] Support -bundle
Not 100% sure but it appears that bundles are almost identical to
dylibs, aside from the fact that they do not contain `LC_ID_DYLIB`. ld64's code
seems to treat bundles and dylibs identically in most places.

Supporting bundles allows us to run e.g. XCTests, as all test suites are
compiled into bundles which get dynamically loaded by the `xctest` test runner.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D87856
2020-09-25 11:28:32 -07:00
Jez Ng
e4e673e75a [lld-macho] Implement support for PIC
* Implement rebase opcodes. Rebase opcodes tell dyld where absolute
  addresses have been encoded in the binary. If the binary is not loaded
  at its preferred address, dyld has to rebase these addresses by adding
  an offset to them.
* Support `-pie` and use it to test rebase opcodes.

This is necessary for absolute address references in dylibs, bundles etc
to work.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D87199
2020-09-25 11:28:31 -07:00
Jez Ng
c32e69b2ce [lld-macho][re-land] Initial support for common symbols
Fix earlier build break via a static_cast.

This reverts commit 8112d494d344dc0935d5c078f066a43d7c984e0c.

Differential Revision: https://reviews.llvm.org/D86909
2020-09-24 15:00:20 -07:00
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
Muhammad Omair Javaid
8112d494d3 Revert "[lld-macho] Initial support for common symbols"
This reverts commit 63ace77962543f961f1d566dd1243b1fb37129ef.

Breaks LLDB Arm build:
http://lab.llvm.org:8011/builders/lldb-arm-ubuntu/builds/4409
2020-09-24 12:26:40 +05:00
Jez Ng
9c70281497 [lld-macho][NFC] Make != nullptr implicit 2020-09-23 20:09:49 -07:00
Jez Ng
ca8752a793 [lld-macho][NFC] Refactor syslibroot / library path lookup
* Move computation of systemLibraryRoots into a separate function, so we
  can add more functionality to it without things becoming unwieldy
* Have `getSearchPaths` and related functions return by value instead of
  by output parameter. NRVO should ensure that performance is unaffected.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D87959
2020-09-23 19:26:41 -07:00
Jez Ng
98f03908d0 [lld-macho] Support -weak_lx, -weak_library, -weak_framework
They cause their corresponding libraries / frameworks to be loaded via
`LC_LOAD_WEAK_DYLIB` instead of `LC_LOAD_DYLIB`.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D87929
2020-09-23 19:26:41 -07:00
Jez Ng
63ace77962 [lld-macho] Initial support for common symbols
On Unix, it is traditionally allowed to write variable definitions without
initialization expressions (such as "int foo;") to header files. These are
called tentative definitions.

The compiler creates common symbols when it sees tentative definitions. When
linking the final binary, if there are remaining common symbols after name
resolution is complete, the linker converts them to regular defined symbols in
a `__common` section.

This diff implements most of that functionality, though we do not yet handle
the case where there are both common and non-common definitions of the same
symbol.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D86909
2020-09-23 19:26:40 -07:00
Greg McGary
8f2c31f22b [lld-macho] handle options -search_paths_first, -search_dylibs_first
Differential Revision: https://reviews.llvm.org/D88054
2020-09-23 14:56:33 -07:00
Greg McGary
fa5f945212 [lld-macho] cleanup unimplemented-option warnings
Remove all spurious `HelpHidden` flags from  `lld/MachO/Options.td`. Add test for `HelpHidden` to `warnIfUnimplementedOption()` so that the empty `// handled elsewhere` case is unnecessary.

Reviewed By: #lld-macho, int3, smeenai

Differential Revision: https://reviews.llvm.org/D88160
2020-09-23 14:38:23 -07:00
Greg McGary
145ce86dba [lld-macho] handle option -headerpad_max_install_names
Differential Revision: https://reviews.llvm.org/D88064
2020-09-22 17:24:19 -07:00
Greg McGary
7afbf3192d [lld-macho] minimally handle option -dynamic
Stifle the warning for unimplemented option `-dyamic`, since it is already the default. Add `Config::staticLink` and skeletal support for altering the flag, but otherwise leave the option `-static` as hidden and its warning in place.

Differential Revision: https://reviews.llvm.org/D88045
2020-09-22 08:03:44 -07:00
Jez Ng
62b39b3a0c [lld-macho] Implement -all_load
Differential Revision: https://reviews.llvm.org/D86640
2020-08-26 19:21:17 -07:00
Jez Ng
cf918c809b [lld-macho] Implement -ObjC
It's roughly like -force_load with some filtering.

Differential Revision: https://reviews.llvm.org/D86181
2020-08-26 19:20:55 -07:00
Jez Ng
7394460d87 [lld-macho] Handle TAPI and regular re-exports uniformly
The re-exports list in a TAPI document can either refer to other inlined
TAPI documents, or to on-disk files (which may themselves be TBD or
regular files.) Similarly, the re-exports of a regular dylib can refer
to a TBD file.

Differential Revision: https://reviews.llvm.org/D85404
2020-08-26 19:20:48 -07:00
Jez Ng
6336c042f6 [lld-macho] Make it possible to re-export .tbd files
Two things needed fixing for that to work:

1. getName() no longer returns null for DylibFiles constructed from TAPIs
2. markSubLibrary() now accepts .tbd as a possible extension

Differential Revision: https://reviews.llvm.org/D86180
2020-08-26 19:20:42 -07:00
Jez Ng
3e7a86e366 [lld-macho] Fall back to raw path if we don't find anything under syslibroot
This matches ld64's behavior

Differential Revision: https://reviews.llvm.org/D85992
2020-08-26 19:20:35 -07:00
Jez Ng
e48d1262b8 [lld-macho] Support -rpath
Pretty straightforward; just emits LC_RPATH for dyld to consume.

Note that lld itself does not yet support dylib lookup via @rpath.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85701
2020-08-12 19:50:28 -07:00
Jez Ng
437e6bd286 [lld-macho] Implement -force_load
It's similar to lld-ELF's `-whole-archive`, but applied to individual
archives instead of to a series of them.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D85550
2020-08-12 19:50:27 -07:00
Jez Ng
c3eb1e2754 [lld-macho] Add error handling for malformed TBD files
Previously, lld would crash while complaining that `Expected<T>
must be checked before access or destruction`.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85403
2020-08-12 19:50:13 -07:00
Jez Ng
7e6d675499 [lld-macho] Avoid unnecessary shared_ptr in DylibFile ctor
DylibFile doesn't store a pointer to its InterfaceFile
parameter, so there's no need to use a shared_ptr.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85402
2020-08-12 19:50:12 -07:00
Greg McGary
49fb1c2e90 [lld-macho] improve handling of -platform_version
This improves the handling of `-platform_version` by addressing the FIXME in the code to process the arguments.

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D81413
2020-08-10 18:47:16 -07:00
Greg McGary
a379f2c251 [lld-macho] Handle command-line option -sectcreate SEG SECT FILE
Handle command-line option `-sectcreate SEG SECT FILE`, which inputs a binary blob from `FILE` into `SEG,SECT`

Reviewed By: int3

Differential Revision: https://reviews.llvm.org/D85501
2020-08-10 18:47:13 -07:00