Commit Graph

150 Commits

Author SHA1 Message Date
Alexander Shaposhnikov f1e4e2fb20 [lld][MachO] Refactor handling of subsections
This diff is a preparation for fixing FunStabs (incorrect size calculation).
std::map<uint32_t, InputSection*> (SubsectionMap) is replaced with
a sorted vector + binary search. If .subsections_via_symbols is set
this vector will contain the list of subsections, otherwise,
the offsets will be used for calculating the symbols sizes.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D98837
2021-03-31 16:52:53 -07:00
Greg McGary 427d359721 [lld-macho][NFC] Drop unnecessary macho:: namespace prefix on unambiguous references to Symbol
Within `lld/macho/`, only `InputFiles.cpp` and `Symbols.h` require the `macho::` namespace qualifier to disambiguate references to `class Symbol`.

Add braces to outer `for` of a 5-level single-line `if`/`for` nest.

Differential Revision: https://reviews.llvm.org/D99555
2021-03-30 14:58:35 -07:00
Jez Ng a43f588e01 [lld-macho] Implement -segprot
Addresses llvm.org/PR49405.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D99389
2021-03-29 14:08:12 -04:00
Jez Ng 94e369400e [lld-macho] Fix parsing of --time-trace-{granularity,file}
Summary: We needed to use `Joined` instead of `Flag`. This wasn't caught
because the relevant test that was copied from LLD-ELF was still
invoking LLD-ELF instead of LLD-MachO...

Differential Revision: https://reviews.llvm.org/D99313
2021-03-26 18:14:10 -04:00
Jez Ng 45cdceb40c [lld-macho] Support -no_function_starts
Pretty simple code-wise. Also threw in some refactoring:

* Put the functionStartSection under Writer instead of InStruct, since
  it doesn't need to be accessed outside of Writer
* Adjusted the test to put all files under the temp dir instead of at
  the top-level
* Added some CHECK-LABELs to make it clearer where the function starts
  data is

Differential Revision: https://reviews.llvm.org/D99112
2021-03-26 18:14:10 -04:00
Jez Ng 0113cf00b6 [lld-macho] Add support for --threads
Code and test are largely identical to the LLD-ELF equivalents.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99312
2021-03-25 14:51:31 -04:00
Jez Ng 4bcaafeb0e [lld-macho] Add more TimeTraceScopes
I added just enough to allow us to see a top-level breakdown of time taken. This
is the result of loading the time-trace output into `chrome:://tracing`:

ef5e8234f3/tracing.png

Reviewed By: oontvoo

Differential Revision: https://reviews.llvm.org/D99311
2021-03-25 14:51:31 -04:00
Jez Ng 53fd1ada76 [lld-macho] Fix typo in diagnostic message 2021-03-25 14:51:31 -04:00
Vy Nguyen f499b932bf Revert "Revert "Revert "Revert "Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)""""""
This reverts commit 4876ba5b2d.

Third-attemp relanding D98559, new change:
  - explicitly cast enum to underlying type to avoid ambiguity (workaround to clang's bug).
2021-03-23 14:51:05 -04:00
Mehdi Amini 4876ba5b2d Revert "Revert "Revert "Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)"""""
This reverts commit 3c21166a94.
The build is broken (clang-8 host compiler):

lld/MachO/DriverUtils.cpp:271:8: error: use of overloaded operator '<<' is ambiguous (with operand types 'llvm::raw_fd_ostream' and 'lld::macho::DependencyTracker::DepOpCode')
    os << opcode;
    ~~ ^  ~~~~~~
2021-03-23 00:19:12 +00:00
Vy Nguyen 3c21166a94 Revert "Revert "Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)""""
This reverts commit 9670d2e4af.

Second attemp to reland D98559. New changes:
 - inline functions removed from cpp file.
 - updated tests to use CHECK-DAG instead of CHECK-NEXT
 - fixed ambiguous "<<" operator by switching `char` to uint8_t
2021-03-22 19:34:51 -04:00
Vy Nguyen 9670d2e4af Revert "Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)"""
This reverts commit 5ad2c225f3.

bots still  unhappy - revertting again
2021-03-22 14:54:01 -04:00
Vy Nguyen 5ad2c225f3 Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)""
This reverts commit 2554b95db5.

Relanding [lld-macho] Implement -dependency_info (D98559) with changes:
 - inline functions removed from cpp file.
 - updated tests to not check libSystem.tbd with other input files (because of possible indeterministic ordering)
2021-03-22 14:41:57 -04:00
Nico Weber 2554b95db5 Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)"
This reverts commit c53a1322f3.
Test only passes depending on build dir having a lexicographically later name
than the source dir, and doesn't link on mac/win. See
https://reviews.llvm.org/D98559#2640265 onward.
2021-03-21 16:35:38 -04:00
Vy Nguyen c53a1322f3 [lld-macho] Implement -dependency_info (partially - more opcodes needed)
Bug: https://bugs.llvm.org/show_bug.cgi?id=49278
The flag is not well documented, so this implementation is based on observed behaviour.

When specified, `-dependency_info <path>` produced a text file containing information pertaining to the current linkage, such as input files, output file, linker version, etc.

This file's layout is also not documented, but it seems to be a series of null ('\0') terminated strings in the form `<op code><path>`

`<op code>` could be:
   `0x00` : linker version
   `0x10` : input
   `0x11` : files not found(??)
   `0x40` : output

`<path>` : is the file path, except for the linker-version case.

(??) This part is a bit unclear. I think it means all the files the linker attempted to look at, but could not find.

Differential Revision: https://reviews.llvm.org/D98559
2021-03-21 14:35:46 -04:00
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