* stage1 backend allows configuring the uwtables function attr
via a flag rather than its own logic.
* stage2 defaults to enabling uwtable attr when
linking libunwind, or always on windows
* stage2 makes link_eh_frame_hdr true automatically if uwtable
attr is set to be on for zig functions
* CLI: add -funwind-tables and -fno-unwind-tables to allow the user to
override the defaults.
* hook it up to `zig cc`
closes#9046
Before this change, when one or more of name or value are not known at
comptime, build.zig files must allocate and do the concatanation, which can be
cumbersome, and also adds a redundant allocation when name and value are
slices. The new version only does a single allocation directly in the builder's
allocator to concatonate name and value.
The origional behavior is available in defineCMacroRaw, for use in situations
such as parseing c compiler arguments.
Additionally, several places have been updated to use the new funtions.
I've added these three functions to all switches except NetBSD, because I don't know what the function is named there. I've even added it on the .windows switch since all the posix functions seem to be there anyways.
It turns out the code was not ported correctly from C and produced wrong
results for negative input values. As a bonus fix the NaN codepath by
adding yet another missing piece of code.
Spotted in #9047
The documentation (e.g. `man 7 rtnetlink`) states that ifi_change "is reserved for future use and should be always set to 0xFFFFFFFF". This is no longer true, even though the text hasn't been updated.
The only allowed system libraries that we can link are libraries
that are part of the sysroot such as libc or WASI emulated
subcomponents. This is required as Wasm allows to defer symbol
resolution until load time.
For example, the following import in Zig
```zig
extern "wasi_snapshot_preview1" fn proc_exit() void;
```
would normally result in appending `-lwasi_snapshot_preview1` flag
to the linker line. However, for Wasm/WASI, the symbol is provided
at load rather than link time, therefore, the linker should not be
concerned with resolving the symbol. As a result, we should not
consider system libs by the Wasm linker.
closes#9034
These options were listed under the
"Debug Options (Zig Compiler Development)" heading. Anything in this
section should be considered unstable and can be modified at any time
at any developer's discretion.
Zig has detection for when it is accidentally being called recursively
when trying to find the native libc installation. However it was not
working, resulting in a cryptic failure, because zig tried to execute
a command which had spaces in it rather than tokenizing it.
This improves the user experience of `zig cc` for systems that Zig
does not support cross-compiling for.
Closes#8960
I want the language reference to be divorced from any particular
community. Also remove the call to action since the docs are
known to be incomplete and are not the current focus of the project.
Closes#9055
