This matters for example for the iPhoneSimulator14.0.sdk, which has
a System/Library/Frameworks/UIKit.framework/UIKit that has
LC_BUILD_VERSION with minos of 14.0, so linking against that file
will produce warnings like:
.../iPhoneSimulator14.0.sdk/System/Library/Frameworks/UIKit.framework/UIKit
has version 14.0.0, which is newer than target minimum of 12.0.0
when targeting x86_64-apple-ios12.0-simulator. That doens't happen when
linking against UIKit.tbd instead, obviously.
Linking with RC_TRACE_DYLIB_SEARCHING=1 shows that ld64 also searches
the tbd file first, and we already get that right for non-framework
dylibs.
Fixes crbug.com/1249456.
Differential Revision: https://reviews.llvm.org/D109768
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
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
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.)
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
Also adjust a few comments, and move the DylibFile comment talking about
umbrella next to the parameter again.
Differential Revision: https://reviews.llvm.org/D103783
D103423 neglected to call `parseReexports()` for nested TBD
documents, leading to symbol resolution failures when trying to look up
a symbol nested more than one level deep in a TBD file. This fixes the
regression and adds a test.
It also appears that `umbrella` wasn't being set properly when calling
`parseLoadCommands` -- it's supposed to resolve to `this` if `nullptr`
is passed. I didn't write a failing test case for this but I've made
`umbrella` a member so the previous behavior should be preserved.
Reviewed By: #lld-macho, thakis
Differential Revision: https://reviews.llvm.org/D103586
I forgot to move the message() call around as requested in D103428
before committing that change. Move it now.
Also, improve the ordinal uniq'ing comment. I hadn't realized that the
distinct-but-identical files happen with --reproduce and not in general.
No behavior change.
Differential Revision: https://reviews.llvm.org/D103522
We used to not print dylibs referenced by other dylibs in `-t` mode. This
affected reexports, and with `-flat_namespace` also just dylibs loaded by
dylibs. Now we print them.
Fixes PR49514.
Differential Revision: https://reviews.llvm.org/D103428
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
loadDylib() keeps a name->DylibFile cache, but it only writes
to the cache once the DylibFile constructor has completed.
So dylib loads done recursively from the DylibFile constructor
wouldn't use the cache.
Now, we load additional dylibs after writing to the cache,
which means the cache now gets used for dylibs loaded because
they're referenced from other dylibs.
Related to PR49514 and PR50101, but no dramatic behavior change in itself.
(Technically we no longer crash when a tbd file reexports itself,
but that doesn't happen in practice. We now accept it silently instead
of crashing; ld64 has a diag for the reexport cycle.)
Differential Revision: https://reviews.llvm.org/D103423
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
We were taking a reference to a value in `loadedDylibs`, which in turn
called `make<DylibFile>()`, which could then recursively call
`loadDylibs`, which would then potentially resize `loadedDylibs` and
invalidate that reference.
Fixes PR50101.
Reviewed By: #lld-macho, oontvoo
Differential Revision: https://reviews.llvm.org/D101175
I went through the callers of `readFile()` and `addFile()` in Driver.cpp
and checked that the options that use them all get rewritten in the
--reproduce response file. -(un)exported_symbols_list and -bundle_loader
weren't, so add them.
Also spruce up the test for reproduce a bit and actually try linking
with the exptracted repro archive.
Motivated by the response file in PR50098 complaining abou the
-exported_symbols_list path being wrong :)
Differential Revision: https://reviews.llvm.org/D101182
TextAPI/ELF has moved out into InterfaceStubs, so theres no longer a
need to seperate out TextAPI between formats.
Reviewed By: ributzka, int3, #lld-macho
Differential Revision: https://reviews.llvm.org/D99811
The main challenge was handling the different on-disk structures (e.g.
`mach_header` vs `mach_header_64`). I tried to strike a balance between
sprinkling `target->wordSize == 8` checks everywhere (branchy = slow, and ugly)
and templatizing everything (causes code bloat, also ugly). I think I struck a
decent balance by judicious use of type erasure.
Note that LLD-ELF has a similar architecture, though it seems to use more templating.
Linking chromium_framework takes about the same time before and after this
change:
N Min Max Median Avg Stddev
x 20 4.52 4.67 4.595 4.5945 0.044423204
+ 20 4.5 4.71 4.575 4.582 0.056344803
No difference proven at 95.0% confidence
Reviewed By: #lld-macho, oontvoo
Differential Revision: https://reviews.llvm.org/D99633
This reverts commit 4876ba5b2d.
Third-attemp relanding D98559, new change:
- explicitly cast enum to underlying type to avoid ambiguity (workaround to clang's bug).
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;
~~ ^ ~~~~~~
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
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)
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.
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
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
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
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
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
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
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.
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
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
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
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
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
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
Nico Weber