Emscripten currently implements `emscripten_return_address()` by calling
out into JavaScript and parsing a stack trace, which introduces
significant overhead that we would prefer to avoid in release builds.
This is especially problematic for allocators because the generic parts
of `std.mem.Allocator` make frequent use of `@returnAddress`, even
though very few allocator implementations even observe the return
address, which makes allocators nigh unusable for performance-critical
applications like games if the compiler is unable to devirtualize the
allocator calls.
The old logic only decremented `remaining_prelink_tasks` if `bin_file`
was not `null`. This meant that on `-fno-emit-bin` builds with
registered prelink tasks (e.g. C source files), we exited from
`Compilation.performAllTheWorkInner` early, assuming a prelink error.
Instead, when `bin_file` is `null`, we still decrement
`remaining_prelink_tasks`; we just don't do any actual work.
Resolves: #22682
When determining the type of RC compiler, meson passes `/?` or `--version` and then reads from `stdout` looking for particular string(s) anywhere in the output.
So, by adding the string "Microsoft Resource Compiler" to the `/?` output, meson will recognize `zig rc` as rc.exe and give it the correct options, which works fine since `zig rc` is drop-in CLI compatible with rc.exe.
This allows using `zig rc` with meson for (cross-)compiling, by either:
- Setting WINDRES="zig rc" or putting windres = ['zig', 'rc'] in the cross-file
+ This will work like rc.exe, so it will output .res files. This will only link successfully if you are using a linker that can do .res -> .obj conversion (so something like zig cc, MSVC, lld)
- Setting WINDRES="zig rc /:output-format coff" or putting windres = ['zig', 'rc', '/:output-format', 'coff'] in the cross-file
+ This will make meson pass flags as if it were rc.exe, but it will cause the resulting .res file to actually be a COFF object file, meaning it will work with any linker that handles COFF object files
Example cross file that uses `zig cc` (which can link `.res` files, so `/:output-format coff` is not necessary) and `zig rc`:
```
[binaries]
c = ['zig', 'cc', '--target=x86_64-windows-gnu']
windres = ['zig', 'rc']
[target_machine]
system = 'windows'
cpu_family = 'x86_64'
cpu = 'x86_64'
endian = 'little'
```
LLD expects the library file name (minus extension) to be exactly libmingw32. By
calling it mingw32 previously, we prevented it from being detected as being in
LLD's list of libraries that are excluded from the MinGW-specific auto-export
mechanism.
b9d27ac252/lld/COFF/MinGW.cpp (L30-L56)
As a result, a DLL built for *-windows-gnu with Zig would export a bunch of
internal MinGW symbols. This sometimes worked out fine, but it could break at
link or run time when linking an EXE with a DLL, where both are targeting
*-windows-gnu and thus linking separate copies of mingw32.lib. In #23204, this
manifested as the linker getting confused about _gnu_exception_handler() because
it was incorrectly exported by the DLL while also being defined in the
mingw32.lib that was being linked into the EXE.
Closes#23204.
This commit reworks how Sema handles arithmetic on comptime-known
values, fixing many bugs in the process.
The general pattern is that arithmetic on comptime-known values is now
handled by the new namespace `Sema.arith`. Functions handling comptime
arithmetic no longer live on `Value`; this is because some of them can
emit compile errors, so some *can't* go on `Value`. Only semantic
analysis should really be doing arithmetic on `Value`s anyway, so it
makes sense for it to integrate more tightly with `Sema`.
This commit also implements more coherent rules surrounding how
`undefined` interacts with comptime and mixed-comptime-runtime
arithmetic. The rules are as follows.
* If an operation cannot trigger Illegal Behavior, and any operand is
`undefined`, the result is `undefined`. This includes operations like
`0 *| undef`, where the LHS logically *could* be used to determine a
defined result. This is partly to simplify the language, but mostly to
permit codegen backends to represent `undefined` values as completely
invalid states.
* If an operation *can* trigger Illegal Behvaior, and any operand is
`undefined`, then Illegal Behavior results. This occurs even if the
operand in question isn't the one that "decides" illegal behavior; for
instance, `undef / 1` is undefined. This is for the same reasons as
described above.
* An operation which would trigger Illegal Behavior, when evaluated at
comptime, instead triggers a compile error. Additionally, if one
operand is comptime-known undef, such that the other (runtime-known)
operand isn't needed to determine that Illegal Behavior would occur,
the compile error is triggered.
* The only situation in which an operation with one comptime-known
operand has a comptime-known result is if that operand is undefined,
in which case the result is either undefined or a compile error per
the above rules. This could potentially be loosened in future (for
instance, `0 * rt` could be comptime-known 0 with a runtime assertion
that `rt` is not undefined), but at least for now, defining it more
conservatively simplifies the language and allows us to easily change
this in future if desired.
This commit fixes many bugs regarding the handling of `undefined`,
particularly in vectors. Along with a collection of smaller tests, two
very large test cases are added to check arithmetic on `undefined`.
The operations which have been rewritten in this PR are:
* `+`, `+%`, `+|`, `@addWithOverflow`
* `-`, `-%`, `-|`, `@subWithOverflow`
* `*`, `*%`, `*|`, `@mulWithOverflow`
* `/`, `@divFloor`, `@divTrunc`, `@divExact`
* `%`, `@rem`, `@mod`
Other arithmetic operations are currently unchanged.
Resolves: #22743Resolves: #22745Resolves: #22748Resolves: #22749Resolves: #22914
The code did one useless thing and two wrong things:
- ref counting was basically a noop
- last_dir_fd was chosen from the wrong index and also under the wrong
condition
This caused regular crashes on macOS which are now gone.
On updates with failed files, we should refrain from doing any semantic
analysis, or even touching codegen/link. That way, incremental
compilation state is untouched for when the user fixes the AstGen
errors.
Resolves: #23205
* use `tmp.dir.realpathAlloc()` to get full path into tmpDir instances
* use `testing.allocator` where that simplifies things (vs. manual ArenaAllocator for 1 or 2 allocs)
* Trust `TmpDir.cleanup()` to clean up contained files and sub-trees
* Remove some unnecessary absolute paths (enabling WASI to run the tests)
* Drop some no-longer necessary `[_][]const u8` casts
* Add scopes to reduce `var` usage in favor of `const`
This reverts commit 7e0c25eccd8d9bc5b77953dbc9a39a26e383c550.
The `--git-dir` argument is relative to the `-C` argument, making this
patch OK after all.
I added a comment to go along with this since I found it confusing.
Apologies for the revert.
