The changes from https://reviews.llvm.org/D119173 mean that __config no
longer defaults the libc++ ABI to 1, relying on external configuration.
This means Zig must provide the external configuration.
This fixes static libraries built with zig with -lc++ to have the
standard __1 namespace prefix, which had previously regressed in the
llvm15 branch.
When linking libc and compiling natively, Zig tries to integrate with
the system C compiler. However, this caused Zig to fail when no system C
compiler is installed, despite the fact that Zig is perfectly capable of
compiling & linking libc without one.
This commit makes Zig fall back to using its own ability to provide libc
in the case that no C compiler is installed. For glibc, it means
sometimes getting the warning "zig cannot build new glibc version abc,
providing instead xyz".
Ideally, Zig would do some more validation about the system libraries
being linked against, and report an error in case it could not provide
the exact correct libc version of the system libraries (or that the
system libraries themselves conflict with each other), however, I think
it is fair to call that a separate enhancement.
Before, Zig tried to use its own libc files (e.g. glibc) when there were
no system libs being linked. This prevented building against native
glibc on systems that have newer glibc than the ones Zig provides.
Closes#12797
This adds the following for passthrough to lld:
- `--print-gc-sections`
- `--print-icf-sections`
- `--print-map`
I am not adding these to the cache manifest, since it does not change
the produced artifacts.
Tested with an example from #11398: it successfully prints the resulting
map and the GC'd sections.
This is problematic because in practice it depends on whether the
compiler backend supports it too, as evidenced by the TODO comment about
LLVM not supporting some architectures that in fact do support tail
calls.
Instead this logic is organized strategically in src/target.zig, part of
the internal compiler source code, and the behavior tests in question
duplicate some logic for deciding whether to proceed with the test.
The proper place to expose this flag is in `@import("builtin")` - the
generated source file - so that third party compilers can advertise
whether they support tail calls.
This commit enables `-u <symbol>` for ELF and `-include:<symbol>` for
COFF linkers for use internally. This means we do not expose these
flags to the users just yet, however, we make use of them internally
whenever required. One such use case is forcing inclusion of
`_tls_index` when linking for Windows with mingw and LTO and dead
code stripping enabled. This ensures we add `_tls_index` to the symbol
resolver as an undefined symbol and force the linker to include an atom
that provides it marking it a dead-code-stripping root - meaning it will
not be garbage collected by the linker no matter what.
Commit eb3f7d2f37cab1d3df7c4493b8239e802b83e521 changed the order of CLI
args passed to clang, making object-specific "extra flags" passed first.
However, these are supposed to be able to override other flags, and this
behavior is exploited by workarounds in mingw.zig to disable LTO.
This commit rectifies the situation by moving extra flags back to being
passed after the call to addCCArgs().
When the entire purpose of this compilation is to perform a single zig
cc operation we could "tail call" clang by doing an execve, and any use
of the caching system would actually be problematic since the user is
presumably doing their own caching by using dep file flags.
Fixes#12317
This reverts 6d679eb2bcbe76e389c02e0bb4d4c4feb2847783 and additionally
changes the command line parameters passed to Clang to match.
Clang 14 defaults to DWARFv5 which is an interesting choice. v5 has been
out for 5 years and yet Valgrind does not support it, and apparently
neither does either GDB or LLD, I haven't determined which, but I wasn't
able to use GDB to debug my LLVM-emitted dwarf 5 zig code that was linked
with LLD.
A couple years ago when I was working on the self-hosted ELF linker, I
emitted DWARFv5 but then downgraded to v4 when I realized that third
party tools were stuck in the past. Years later, they still are.
Hopefully, Clang 14's bold move will inspire third party tools to get
their shit together, however, in the meantime, everything's broken, so
we're passing `-gdwarf-4` to clang and instructing LLVM to emit DWARFv4.
Note that Zig's std.debug code *does* support DWARFv5 already as of a
previous commit that I made today.
This reverts commit 7cbd586ace46a8e8cebab660ebca3cfc049305d9.
This is causing a fail to build from source:
```
./lib/std/fmt.zig:492:17: error: cannot format optional without a specifier (i.e. {?} or {any})
@compileError("cannot format optional without a specifier (i.e. {?} or {any})");
^
./src/link/MachO/Atom.zig:544:26: note: called from here
log.debug(" RELA({s}) @ {x} => %{d} in object({d})", .{
^
```
I looked at the code to fix it but none of those args are optionals.
This is really minor but the issue this fixes is that if you copy-paste this output of `--show-builtin` into your `build.zig` for example then the formatter will format
```
pub const os = std.Target.Os{
.tag = .freestanding,
.version_range = .{ .none = {} }
};
```
to
```
pub const os = std.Target.Os{ .tag = .freestanding, .version_range = .{ .none = {} } };
```
which doesn't match the output.
With this comma, the output will stay the way it is after a `zig fmt`.
* make the setting in the linker backend be non-optional; by this time
all defaults are supposed to be resolved.
* integrate with `zig cc`
* change the CLI parsing to match C compiler parsing, allowing
`--compress-debug-sections` alone to choose a default encoding of
zlib.
Future improvement: make plain error notes actually render as notes
rather than errors, but keep them as errors for the case of
sub-compilation errors, e.g. when compiler-rt has compilation errors.
MachO linker now handles `-needed-l<name>`, `-needed_library=<name>`
and `-needed_framework=<name>`. While on macOS `-l` is equivalent
to `-needed-l`, and `-framework` to `-needed_framework`, it can be
used to the same effect as on Linux if combined with `-dead_strip_dylibs`.
This commit also adds handling for `-needed_library` which is macOS
specific flag only (in addition to `-needed-l`).
Finally, in order to leverage new linker testing harness, this commit
added ability to specify lowering to those flags via `build.zig`:
`linkSystemLibraryNeeded` (and related), and `linkFrameworkNeeded`.
Includes both traditiona and incremental codepaths with one caveat that
in incremental case, the requested size cannot be smaller than the
default padding size due to prealloc required due to incremental nature
of linking.
Also parse `-headerpad_max_install_names`, however, not actionable just yet -
missing implementation.
