75 Commits

Author SHA1 Message Date
Nico Weber
2554b95db5 Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)"
This reverts commit c53a1322f329e29446c7625da423f58f09ec1a55.
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
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
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
4af1522a85 [lld-macho] Rework length check when opening input files
This reverts diff D97610 (commit 0223ab035c199e537a0040857ba147ced87fd533) 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
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
Vy Nguyen
5a856f5b44 Reland [lld-macho]Implement bundle_loader
Reland 1a0afcf518717f61d45a1cdc6ad1a6436ec663b1
  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 1a0afcf518717f61d45a1cdc6ad1a6436ec663b1.
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
Nico Weber
f710bb7063 lld: Replace some lld::outs()s with message()
No behavior change.
2020-12-17 16:19:09 -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
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
7cb0a373d1 [mac/lld] Implement -t
Goes well with `-why_load` to get an idea of load order.

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

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

Differential Revision: https://reviews.llvm.org/D92496
2020-12-02 18:33:12 -05:00
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
c0e4020c92 [lld-macho] Implement -fatal_warnings
Differential Revision: https://reviews.llvm.org/D91894
2020-11-30 09:29:21 -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
d20abb1ec3 [mac/lld] Add support for response files
ld64 learned about them in Xcode 12, so we should too.

Differential Revision: https://reviews.llvm.org/D92149
2020-11-30 08:23:58 -05:00
Nico Weber
11b7625833 [lld/mac] Implement basic typo correction for flags
Also use "unknown flag 'flag'" instead of "unknown flag: flag" for
consistency with the other ports.

Differential Revision: https://reviews.llvm.org/D91970
2020-11-24 11:33:39 -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
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