Commit Graph

35 Commits

Author SHA1 Message Date
Kaining Zhong aab0f2264a [lld-macho] Fix dangling string reference when adding frameworks
In Driver.cpp, addFramework used std::string instance to represent the path of a framework, which will be freed after the function returns. However, this string is stored in loadedArchive, which will be used later to compare with path of newly added frameworks. This caused https://bugs.llvm.org/show_bug.cgi?id=52133. A test is included in this commit to reproduce this bug.

Now resolveDylibPath returns a StringRef instance, and it uses StringSaver to save its data, then returns it to functions on the top. This ensures the resolved framework path is still valid after LC_LINKER_OPTION is parsed.

Reviewed By: int3, #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D111706
2021-10-20 11:21:40 -04:00
Jez Ng 9065fe5591 [lld-macho] Refactor archive loading
The previous logic was duplicated between symbol-initiated
archive loads versus flag-initiated loads (i.e. `-force_load` and
`-ObjC`). This resulted in code duplication as well as redundant work --
we would create Archive instances twice whenever we had one of those
flags; once in `getArchiveMembers` and again when we constructed the
ArchiveFile.

This was motivated by an upcoming diff where we load archive members
containing ObjC-related symbols before loading those containing
ObjC-related sections, as well as before performing symbol resolution.
Without this refactor, it would be difficult to do that while avoiding
loading the same archive member twice.

Differential Revision: https://reviews.llvm.org/D108780
2021-08-26 18:52:07 -04:00
Leonard Grey 5acc6d4572 [lld-macho] Disambiguate bitcode files with the same name by archive name/offset in archive
Ported from COFF/ELF; test is adapted from
test/COFF/thinlto-archivecollision.ll

LTO expects every bitcode file to have a unique name. If given multiple bitcode
files with the same name, it errors with "Expected at most one ThinLTO module
per bitcode file".

This change incorporates the archive name, to disambiguate members with the
same name in different archives and the offset in archive to disambiguate
members with the same name in the same archive.

Differential Revision: https://reviews.llvm.org/D106179
2021-07-22 22:50:25 -04:00
Jez Ng f6e84a84f9 [lld-macho][nfc] Avoid using std::map for PlatformKinds
The mappings we were using had a small number of keys, so a vector is
probably better. This allows us to remove the last usage of std::map in
our codebase.

I also used `removeSimulator` to simplify the code a bit further.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D105786
2021-07-11 18:24:53 -04:00
Jez Ng a79c018325 Revert "[lld-macho] Have path-related functions return std::string, not StringRef"
This reverts commit 1d31fb8d12.

Making `rerootPath` return a temporary std::string caused a
use-after-free:

https://ci.chromium.org/ui/p/chromium/builders/try/win_upload_clang/1608/overview
2021-06-18 22:43:49 -04:00
Jez Ng 1d31fb8d12 [lld-macho] Have path-related functions return std::string, not StringRef
findLibrary() returned a StringRef while findFramework & other helper
functions returned std::strings. Standardize on std::string.

(I initially tried making the helper functions all return StringRefs,
but I realized we shouldn't return input StringRefs since their
lifetimes would not be obvious from the calling code.)
2021-06-18 16:36:14 -04:00
Nico Weber e87c095af3 [lld/mac] Print dylib search details with --print-dylib-search or RC_TRACE_DYLIB_SEARCHING
For debugging dylib loading, it's useful to have some insight into what
the linker is doing.

ld64 has the undocumented RC_TRACE_DYLIB_SEARCHING env var
for this printing dylib search candidates.

This adds a flag --print-dylib-search to make lld print the seame information.
It's useful for users, but also for writing tests. The output is formatted
slightly differently than ld64, but we still support RC_TRACE_DYLIB_SEARCHING
to offer at least a compatible way to trigger this.

ld64 has both `-print_statistics` and `-trace_symbol_output` to enable
diagnostics output. I went with "print" since that seems like a more
straightforward name.

Differential Revision: https://reviews.llvm.org/D103985
2021-06-09 22:08:20 -04:00
Vy Nguyen 8f89c054af [lld-macho][nfc] Remove unnecessary use of Optional<T*>
In all of these cases, the functions could simply return a nullptr instead of {}.
There is no case where Optional<nullptr> has a special meaning.

Differential Revision: https://reviews.llvm.org/D103489
2021-06-01 18:35:31 -04:00
Jez Ng 20f51ffe67 [lld-macho] Have --reproduce account for path rerooting
We need to account for path rerooting when generating the response
file. We could either reroot the paths before generating the file, or pass
through the original filenames and change just the syslibroot. I've opted for
the latter, in order that the reproduction run more closely mirrors the
original.

We must also be careful *not* to make an absolute path relative if it is
shadowed by a rerooted path. See repro6.tar in reroot-path.s for
details.

I've moved the call to `createResponseFile()` after the initialization of
`config->systemLibraryRoots`, since it now needs to know what those roots are.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D101224
2021-05-05 14:41:01 -04:00
Jez Ng 174deb0539 [lld-macho] clang-format cleanup
find . -type f -name "*.cpp" -o -name "*.h" | xargs clang-format -i
2021-04-06 14:26:13 -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 9a2e2de15f [lld-macho] Change loadReexport to handle the case where a TAPI re-exports to reference documents nested within other TBD.
Currently, it was delibrately impleneted to not handle this case, but as it has turnt out, we need this feature.
The concrete use case is
       `System/Library/Frameworks/Cocoa.framework/Versions/A/Cocoa` reexports
               /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit , which then rexports
                    /System/Library/PrivateFrameworks/UIFoundation.framework/Versions/A/UIFoundation

The current implemention uses a global currentTopLevelTapi, which is not reset until it finishes loading the whole tree.
This is a problem because if the top-level is set to Cocoa, then when we get to UIFoundation, it will try to find UIFoundation in the current top level, which is Cocoa and will not find it.

The right thing should be:
 - When loading a library from a TBD file, re-exports need to be looked up in the auxiliary documents within the same TBD.
 - When loading from an actual dylib, no additional TBD documents need to be examined.
 - In no case does a re-export mentioned in one TBD file need to be looked up in a document in an auxiliary document from a different TBD file

Differential Revision: https://reviews.llvm.org/D97438
2021-03-02 12:14:31 -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
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
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 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
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
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
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 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
Greg McGary 7df80e3f23 [lld-macho] Specify the complete set of command-line options for ld64
This is a complete Options.td compiled from ld(1) dated 2018-03-07 and
cross checked with ld64 source code version 512.4 dated 2018-03-18.

This is the first in a series of diffs for argument handling. Follow-ups
will include switch cases for all the new instances of `OPT_foo`, and
parsing/validation of arguments attached to options, e.g., more code
akin to `OPT_platform_version` and associated `parsePlatformVersion()`.

Reviewed By: smeenai

Differential Revision: https://reviews.llvm.org/D80582
2020-06-15 12:50:20 -07:00
Fangrui Song 6acd300375 Reland D75382 "[lld] Initial commit for new Mach-O backend"
With a fix for http://lab.llvm.org:8011/builders/clang-cmake-armv8-lld/builds/3636

Also trims some unneeded dependencies.
2020-04-02 12:03:43 -07:00
Oliver Stannard af39151f3c Revert "[lld] Initial commit for new Mach-O backend"
This is causing buildbot failures on 32-bit hosts, for example:
http://lab.llvm.org:8011/builders/clang-cmake-armv8-lld/builds/3636

This reverts commit 03f43b3aca.
2020-04-02 13:23:30 +01:00
Jez Ng 03f43b3aca [lld] Initial commit for new Mach-O backend
Summary:
This is the first commit for the new Mach-O backend, designed to roughly
follow the architecture of the existing ELF and COFF backends, and
building off work that @ruiu and @pcc did in a branch a while back. Note
that this is a very stripped-down commit with the bare minimum of
functionality for ease of review. We'll be following up with more diffs
soon.

Currently, we're able to generate a simple "Hello World!" executable
that runs on OS X Catalina (and possibly on earlier OS X versions; I
haven't tested them). (This executable can be obtained by compiling
`test/MachO/relocations.s`.) We're mocking out a few load commands to
achieve this -- for example, we can't load dynamic libraries, but
Catalina requires binaries to be linked against `dyld`, so we hardcode
the emission of a `LC_LOAD_DYLIB` command. Other mocked out load
commands include LC_SYMTAB and LC_DYSYMTAB.

Differential Revision: https://reviews.llvm.org/D75382
2020-03-31 11:58:47 -07:00