Commit Graph

185 Commits

Author SHA1 Message Date
Vy Nguyen 66f340051a [lld-macho] Define __mh_*_header synthetic symbols.
Bug: https://bugs.llvm.org/show_bug.cgi?id=49290

    Differential Revision: https://reviews.llvm.org/D97007
2021-03-19 14:14:40 -04:00
caoming.roy ed8bff13dc [lld-macho] implement options -map
Implement command-line options -map

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D98323
2021-03-18 10:39:19 -04:00
Greg McGary db1e845a96 [lld-macho] Handle error cases properly for -exported_symbol(s_list)
This fixes defects in D98223 [lld-macho] implement options -(un)exported_symbol(s_list):
* disallow export of hidden symbols
* verify that whitelisted literal names are defined in the symbol table
* reflect export-status overrides in `nlist` attribute of `N_EXT` or `N_PEXT`

Thanks to @thakis for raising these issues

Differential Revision: https://reviews.llvm.org/D98381
2021-03-16 21:20:39 -07:00
Jez Ng 38a6374564 [lld-macho] Only codesign by default on arm64 macOS
instead of doing it on all arm64 platforms.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D98446
2021-03-12 17:26:27 -05:00
Jez Ng d8283d9ddc [lld-macho][nfc] Give every SyntheticSection a fake InputSection
Previously, it was difficult to write code that handled both synthetic
and regular sections generically. We solve this problem by creating a
fake InputSection at the start of every SyntheticSection.

This refactor allows us to handle DSOHandle like a regular Defined
symbol (since Defined symbols must be attached to an InputSection), and
paves the way for supporting `__mh_*header` symbols. Additionally, it
simplifies our binding/rebase code.

I did have to extend Defined a little -- it now has a `linkerInternal`
flag, to indicate that `___dso_handle` should not be in the final symbol
table.

I've also added some additional testing for `___dso_handle`.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D98545
2021-03-12 17:26:27 -05:00
Jez Ng 29bbbd06fe [lld-macho] Unbreak build breakage from rG1752f2850685 2021-03-11 13:35:13 -05:00
Jez Ng 1752f28506 [lld-macho][nfc] Remove `MachO::` prefix where possible
Previously, SyntheticSections.cpp did not have a top-level `using namespace
llvm::MachO` because it caused a naming conflict: `llvm::MachO::Symbol` would
collide with `lld::macho::Symbol`.

`MachO::Symbol` represents the symbols defined in InterfaceFiles (TBDs). By
moving the inclusion of InterfaceFile.h into our .cpp files, we can avoid this
name collision in other files where we are only dealing with LLD's own symbols.

Along the way, I removed all unnecessary "MachO::" prefixes in our code.

Cons of this approach: If TextAPI/MachO/Symbol.h gets included via some other
header file in the future, we could run into this collision again.

Alternative 1: Have either TextAPI/MachO or BinaryFormat/MachO.h use a different
namespace. Most of the benefit of `using namespace llvm::MachO` comes from being
able to use things in BinaryFormat/MachO.h conveniently; if TextAPI was under a
different (and fully-qualified) namespace like `llvm::tapi` that would solve our
problems. Cons: lots of files across llvm-project will need to be updated, and
folks who own the TextAPI code need to agree to the name change.

Alternative 2: Rename our Symbol to something like `LldSymbol`. I think this is
ugly.

Personally I think alternative #1 is ideal, but I'm not sure the effort to do it is
worthwhile, this diff's halfway solution seems good enough to me. Thoughts?

Reviewed By: #lld-macho, oontvoo, MaskRay

Differential Revision: https://reviews.llvm.org/D98149
2021-03-11 13:28:08 -05:00
Thorsten Schütt 50c1b21851 [lld-macho] minimal TimeTrace support
This is the minimal port from ELF. Any extension should easy from here

Test plan: ninja check-all-macho

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D98419
2021-03-11 15:30:45 +01:00
Greg McGary 98fe9e41f7 [lld-macho][NFC] add const to pointer/reference induction variables of range-based for loops
Pointer and reference induction variables of range-based for loops are often const, and code authors often lax about qualifying them.

Differential Revision: https://reviews.llvm.org/D98317
2021-03-10 12:07:31 -08:00
Nico Weber 6e92f468c8 [lld/mac] warn on -install_name without -dylib
The flag doesn't (and shouldn't) have an effect in that case.
ld64 doesn't warn on this, but it seems like a good thing to do.
If it causes problems in practice for some reason, we can revert it.

Also add a dedicated test for install_name.

Differential Revision: https://reviews.llvm.org/D98259
2021-03-10 09:05:44 -05:00
Nico Weber 1aafaaca67 [lld/mac] Implement support for -mark_dead_strippable_dylib
lld doesn't read MH_DEAD_STRIPPABLE_DYLIB to strip dead dylibs yet,
but now it can produce dylibs with it set.

While here, also switch an existing test that looks only at the main Mach-O
header from --all-headers to --private-header.

Differential Revision: https://reviews.llvm.org/D98262
2021-03-10 08:57:46 -05:00
Greg McGary 714ec86c02 [lld-macho][NFC] drop opt:: when already using llvm::opt
Top-level `using llvm::opt` has been present in `lld/MachO/Driver*.cpp` for some time, so remove lingering `opt::` prefixes.

Differential Revision: https://reviews.llvm.org/D98314
2021-03-09 22:08:32 -08:00
Greg McGary fdc0c21973 [lld-macho][NFC] when reasonable, replace auto keyword with type names
lld policy discourages `auto`. Replace it with a type name whenever reasonable. Retain `auto` to avoid ...
* redundancy, as for decls such as `auto *t = mumble_cast<TYPE *>` or similar that specifies the result type on the RHS
* verbosity, as for iterators
* gratuitous suffering, as for lambdas

Along the way, add `const` when appropriate.

Note: a future diff will ...
* add more `const` qualifiers
* remove `opt::` when we are already `using llvm::opt`

Differential Revision: https://reviews.llvm.org/D98313
2021-03-09 22:08:32 -08:00
Greg McGary 06c4aadeb6 [lld-macho] implement options -(un)exported_symbol(s_list)
Implement command-line options to alter a dylib's exported-symbols list:
* `-exported_symbol*` options override the default export list. The export list is compiled according to the command-line option(s) only.
* `-unexported_symbol*` options hide otherwise public symbols.
* `-*exported_symbol PATTERN` options specify a single literal or glob pattern.
* `-*exported_symbols_list FILE` options specify a file containing a series of lines containing symbol literals or glob patterns. Whitespace and `#`-prefix comments are stripped.

Note: This is a simple implementation of the primary use case. ld64 has much more complexity surrounding interactions with other options, many of which are obscure and undocumented. We will start simple and complexity as necessary.

Differential Revision: https://reviews.llvm.org/D98223
2021-03-09 18:43:39 -08:00
Nico Weber 90085d9286 [lld/mac] fix clang-format violation from 0e319bd0be 2021-03-05 12:12:56 -05:00
Nico Weber 0e319bd0be [lld/mac] ad-hoc sign dylibs and bundles on arm64 by default, support -(no_)adhoc_codesign flags
Previously, lld/mac only ad-hoc codesigned executables on arm64.

Matches ld64 behavior. Part of PR49443. Fixes 14 of 17 failures when running
check-llvm with lld as host linker on an M1 MBP.

Differential Revision: https://reviews.llvm.org/D97994
2021-03-05 09:12:34 -05:00
Jez Ng 55a32812fa [lld-macho] Filter TAPI re-exports by target
Previously, we were loading re-exports without checking whether
they were compatible with our target. Prior to {D97209}, it meant that
we were defining dylib symbols that were invalid -- usually a silent
failure unless our binary actually used them. D97209 exposed this as an
explicit error.

Along the way, I've extended our TAPI compatibility check to cover the
platform as well, instead of just checking the arch. To this end, I've
replaced MachO::Architecture with MachO::Target in our Config struct.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D97867
2021-03-04 14:36:47 -05:00
Jez Ng b63919e180 [lld-macho] Require -arch and -platform_version to always be specified
We previously defaulted to x86_64 and an unknown platform, which was fine when
we only supported one arch and did no platform checks, but that will no longer
be true going ahead. Therefore, we should require those flags to be specified
whenever the linker is invoked.

Note that LLD-ELF and ld64 both infer the arch from their input object files,
but the usefulness of that is questionable since clang will always specify these
flags, and most of the time `lld` will be invoked via clang.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D97799
2021-03-03 15:52:10 -05:00
Jez Ng 1168736c66 [lld-macho][nfc] Parse more options using getLastArg{Value}
The option-iterating loop should be reserved for options whose command-line
order is important. I think LLD-ELF follows a similar design.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D97797
2021-03-03 15:52:06 -05:00
Greg McGary 4af1522a85 [lld-macho] Rework length check when opening input files
This reverts diff D97610 (commit 0223ab035c) and adds a one-line fix to verify that a `MemoryBufferRef` has sufficient length before reading a 4-byte magic number.

Differential Revision: https://reviews.llvm.org/D97757
2021-03-02 13:00:57 -08:00
Nico Weber 8174f33dc9 [lld/mac] Add support for -flat_namespace
-flat_namespace makes lld emit binaries that use name lookup that's more in
line with other POSIX systems: Instead of looking up symbols as (dylib,name)
pairs by dyld, they're instead looked up just by name.

-flat_namespace has three effects:

1. MH_TWOLEVEL and MH_NNOUNDEFS are no longer set in the Mach-O header
2. All symbols use BIND_SPECIAL_DYLIB_FLAT_LOOKUP as ordinal
3. When a dylib is added to the link, its dependent dylibs are also added,
   so that lld can verify that no undefined symbols remain at the end of
   a link with -flat_namespace. These transitive dylibs are added for symbol
   resolution, but they are not emitted in LC_LOAD_COMMANDs.

-undefined with -flat_namespace still isn't implemented. Before this change,
it was impossible to hit that combination because -flat_namespace caused a
diagnostic. Now that it no longer does, emit a dedicated temporary diagnostic
when both flags are used.

Differential Revision: https://reviews.llvm.org/D97641
2021-03-01 15:25:10 -05:00
Nico Weber ab45289d2e [lld/mac] Make -v print version and search paths in additon to linking, not instead of linking
This matches ld64's behavior.

Differential Revision: https://reviews.llvm.org/D97718
2021-03-01 15:09:46 -05:00
Nico Weber bacacb9d5c [lld/mac] Prefix errors with "ld64.lld" instead of just "lld"
Matches the ELF and COFF ports, which use ld.lld and lld-link, respectively.

While here, also move up `cleanupCallback` to match ELF / COFF.

Differential Revision: https://reviews.llvm.org/D97715
2021-03-01 15:08:19 -05:00
Greg McGary 0223ab035c [lld-macho] check minimum header length when opening linkable input files
Bifurcate the `readFile()` API into ...
* `readRawFile()` which performs no checks, and
* `readLinkableFile()` which enforces minimum length of 20 bytes, same as ld64

There are no new tests because tweaks to existing tests are sufficient.

Differential Revision: https://reviews.llvm.org/D97610
2021-02-27 14:41:40 -08:00
Greg McGary 6f9dd843db [lld-macho] Implement options -rename_section -rename_segment
Implement command-line options to rename output sections & segments.

Differential Revision: https://reviews.llvm.org/D97600
2021-02-27 11:44:12 -08:00
Nico Weber cafb6cd10c [lld/mac] Add some support for dynamic lookup symbols, and implement -U
Dynamic lookup symbols are symbols that work like dynamic symbols
in ELF: They're not bound to a dylib like normal Mach-O twolevel lookup
symbols, but they live in a global pool and dyld resolves them against
exported symbols from all loaded dylibs.

This adds support for dynamical lookup symbols to lld/mac. They are
represented as DylibSymbols with file set to nullptr.

This also uses this support to implement the -U flag, which makes
a specific symbol that's undefined at the end of the link a
dynamic lookup symbol.

For -U, it'd be sufficient to just to a pass over remaining undefined symbols
at the end of the link and to replace them with dynamic lookup symbols then.
But I'd like to use this code to implement flat_namespace too, and that will
require real support for resolving dynamic lookup symbols in SymbolTable. So
this patch adds this now already.

While writing tests for this, I noticed that we didn't set N_WEAK_DEF in the
symbol table for DylibSymbols, so this fixes that too.

Differential Revision: https://reviews.llvm.org/D97521
2021-02-26 16:50:53 -05:00
Vy Nguyen 5a856f5b44 Reland [lld-macho]Implement bundle_loader
Reland 1a0afcf518
  https://reviews.llvm.org/D95913

New change: fix UB bug caused by copying empty path/name. (since the executable does not have a name)
2021-02-22 14:05:12 -05:00
Nico Weber 28d9953af9 [lld/mac] reject -undefined warning and -undefined suppress with -twolevel_namespace
See discussion on https://reviews.llvm.org/D93263

-flat_namespace isn't implemented yet, and neither is -undefined dynamic,
so this makes -undefined pretty pointless in lld/MachO for now. But once
we implement -flat_namespace (which we need to do anyways to get check-llvm
to pass with lld as host linker), the code's already there.

Follow-up to https://reviews.llvm.org/D93263#2491865

Differential Revision: https://reviews.llvm.org/D96963
2021-02-20 13:35:22 -05:00
Vitaly Buka c17547df44 Revert "Implement -bundle_loader"
D95913 passes null pointer into memcpy

This reverts commit 1a0afcf518.
2021-02-19 17:40:07 -08:00
Vy Nguyen 1a0afcf518 Implement -bundle_loader
Differential Revision: https://reviews.llvm.org/D95913

Usage: -bundle_loader <executable>
This option specifies the executable that will load the build output file being linked.
When building a bundle, users can use the --bundle_loader  to specify an executable
that contains symbols referenced, but not implemented in the bundle.
2021-02-18 16:11:37 -05:00
Nico Weber e0b8604e5d [lld/mac] Implement -u flag
Since we emit diagnostics for undefineds in Writer::scanRelocations()
and symbols referenced by -u flags aren't referenced by any relocations,
this needs some manual code (similar to the entry point).

Differential Revision: https://reviews.llvm.org/D94371
2021-02-09 08:23:06 -05:00
Greg McGary 87104faac4 [lld-macho] Add ARM64 target arch
This is an initial base commit for ARM64 target arch support. I don't represent that it complete or bug-free, but wish to put it out for review now that some basic things like branch target & load/store address relocs are working.

I can add more tests to this base commit, or add them in follow-up commits.

It is not entirely clear whether I use the "ARM64" (Apple) or "AArch64" (non-Apple) naming convention. Guidance is appreciated.

Differential Revision: https://reviews.llvm.org/D88629
2021-02-08 18:14:07 -07:00
Jez Ng f843bb82c0 [lld-macho] Force-loading should share code path with regular archive loads
This extends {D92539} to work even when we are loading archive
members via `-force_load`. I uncovered this issue while trying to
force-load archives containing bitcode -- we were segfaulting.

In addition to fixing the `-force_load` case, this diff also addresses
the behavior of `-ObjC` when LTO bitcode is involved -- we need to
force-load those archive members if they contain ObjC categories.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D95265
2021-02-03 13:43:47 -05:00
Jez Ng 163dcd8513 [lld-macho] Associate each Symbol with an InputFile
This makes our error messages more informative. But the bigger motivation is for
LTO symbol resolution, which will be in an upcoming diff. The changes in this
one are largely mechanical.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D94316
2021-02-03 13:43:47 -05:00
Greg McGary 3a9d2f1488 [lld-macho][NFC] refactor relocation handling
Add per-reloc-type attribute bits and migrate code from per-target file into target independent code, driven by reloc attributes.

Many cleanups

Differential Revision: https://reviews.llvm.org/D95121
2021-02-02 10:54:53 -07:00
Jez Ng 697f4e429b [lld-macho] Run ObjCContractPass during LTO
Run the ObjCARCContractPass during LTO. The legacy LTO backend (under
LTO/ThinLTOCodeGenerator.cpp) already does this; this diff just adds that
behavior to the new LTO backend. Without that pass, the objc.clang.arc.use
intrinsic will get passed to the instruction selector, which doesn't know how to
handle it.

In order to test both the new and old pass managers, I've also added support for
the `--[no-]lto-legacy-pass-manager` flags.

P.S. Not sure if the ordering of the pass within the pipeline matters...

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D94547
2021-01-20 14:21:32 -05:00
Nico Weber 1198478c42 [lld/mac] remove redundant null check
This is already checked two lines up. No behavior change.
2021-01-09 21:18:32 -05:00
Jez Ng e98b441a09 [lld-macho] Remove unnecessary llvm:: namespace prefixes 2021-01-09 12:44:35 -05:00
Jez Ng 9d1140e18e [lld-macho] Simulator & DriverKit executables should always be PIE
We didn't have support for parsing DriverKit in our `-platform`
flag, so add that too. Also remove a bunch of unnecessary namespace
prefixes.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D93741
2020-12-23 11:24:12 -05:00
Nico Weber 77fb45e59e [lld/mac] Add --version flag
It's an extension to ld64, but all the other ports have it, and
someone asked for it in PR43721.

While here, change the COFF help text to match the other ports.

Differential Revision: https://reviews.llvm.org/D93491
2020-12-22 22:06:39 -05:00
Nico Weber 13f439a187 [lld/mac] Implement support for private extern symbols
Private extern symbols are used for things scoped to the linkage unit.
They cause duplicate symbol errors (so they're in the symbol table,
unlike TU-scoped truly local symbols), but they don't make it into the
export trie. They are created e.g. by compiling with
-fvisibility=hidden.

If two weak symbols have differing privateness, the combined symbol is
non-private external. (Example: inline functions and some TUs that
include the header defining it were built with
-fvisibility-inlines-hidden and some weren't).

A weak private external symbol implicitly has its "weak" dropped and
behaves like a regular strong private external symbol: Weak is an export
trie concept, and private symbols are not in the export trie.

If a weak and a strong symbol have different privateness, the strong
symbol wins.

If two common symbols have differing privateness, the larger symbol
wins. If they have the same size, the privateness of the symbol seen
later during the link wins (!) -- this is a bit lame, but it matches
ld64 and this behavior takes 2 lines less to implement than the less
surprising "result is non-private external), so match ld64.
(Example: `int a` in two .c files, both built with -fcommon,
one built with -fvisibility=hidden and one without.)

This also makes `__dyld_private` a true TU-local symbol, matching ld64.
To make this work, make the `const char*` StringRefZ ctor to correctly
set `size` (without this, writing the string table crashed when calling
getName() on the __dyld_private symbol).

Mention in CommonSymbol's comment that common symbols are now disabled
by default in clang.

Mention in -keep_private_externs's HelpText that the flag only has an
effect with `-r` (which we don't implement yet -- so this patch here
doesn't regress any behavior around -r + -keep_private_externs)). ld64
doesn't explicitly document it, but the commit text of
http://reviews.llvm.org/rL216146 does, and ld64's
OutputFile::buildSymbolTable() checks `_options.outputKind() ==
Options::kObjectFile` before calling `_options.keepPrivateExterns()`
(the only reference to that function).

Fixes PR48536.

Differential Revision: https://reviews.llvm.org/D93609
2020-12-21 21:23:33 -05:00
Jez Ng 5f9896d3b2 [lld-macho] Support Obj-C symbols in order files
Obj-C symbols may have spaces and colons, which our previous order file
parser would be confused by. The order file format has made the very unfortunate
choice of using colons for its delimiters, which means that we have to use
heuristics to determine if a given colon is part of a symbol or not...

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D93567
2020-12-20 13:49:18 -05:00
Greg McGary cc1cf6332a [lld-macho] Implement option: -undefined TREATMENT
TREATMENT can be `error`, `warning`, `suppress`, or `dynamic_lookup`
The `dymanic_lookup` remains unimplemented for now.

Differential Revision: https://reviews.llvm.org/D93263
2020-12-17 17:40:50 -08:00
Nico Weber f710bb7063 lld: Replace some lld::outs()s with message()
No behavior change.
2020-12-17 16:19:09 -05:00
Jez Ng 811444d7a1 [lld-macho] Add support for weak references
Weak references need not necessarily be satisfied at runtime (but they must
still be satisfied at link time). So symbol resolution still works as per usual,
but we now pass around a flag -- ultimately emitting it in the bind table -- to
indicate if a given dylib symbol is a weak reference.

ld64's behavior for symbols that have both weak and strong references is
a bit bizarre. For non-function symbols, it will emit a weak import. For
function symbols (those referenced by BRANCH relocs), it will emit a
regular import. I'm not sure what value there is in that behavior, and
since emulating it will make our implementation more complex, I've
decided to treat regular weakrefs like function symbol ones for now.

Fixes PR48511.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D93369
2020-12-17 08:49:16 -05:00
dfukalov 9ed8e0caab [NFC] Reduce include files dependency and AA header cleanup (part 2).
Continuing work started in https://reviews.llvm.org/D92489:

Removed a bunch of includes from "AliasAnalysis.h" and "LoopPassManager.h".

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D92852
2020-12-17 14:04:48 +03:00
Nico Weber 09edd9df6e [mac/lld] simplify code using PackedVersion instead of VersionTuple
PackedVersion already does the correct range checks.

No behavior change.

Differential Revision: https://reviews.llvm.org/D93338
2020-12-15 19:23:07 -05:00
Jez Ng 8a5e068823 [lld-macho] Support -sub_umbrella
From what I can tell, it's essentially identical to
`-sub_library`, but it doesn't match files ending in ".dylib".

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D93276
2020-12-15 15:58:26 -05:00
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 542d3b609d.
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 f2710d4b57,
  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 8112d494d3.

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 63ace77962.

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
Jez Ng 25367dfefb [lld-macho] Add .tbd support for frameworks
Required for e.g. linking iOS apps since they don't have a platform-native
SDK

Reviewed By: #lld-macho, compnerd, smeenai

Differential Revision: https://reviews.llvm.org/D85153
2020-08-07 11:04:54 -07:00
Saleem Abdulrasool 0ccda7c232 MachO: support `-syslibroot`
This adds support for the `-syslibroot` option.  This is required to
make the library search order actually function.  With this, it is now
possible to link a test Darwin x86_64 program with lld on Darwin.

Differential Revision: https://reviews.llvm.org/D82252
Reviewed By: Jez Ng
2020-08-05 08:41:24 -07:00