* CLI: change to -mred-zone and -mno-red-zone to match gcc/clang.
* build.zig: remove the double negative and make it an optional bool.
This follows precedent from other flags, allowing the compiler CLI to
be the decider of what is default instead of duplicating the default
value into the build system code.
* Compilation: make it an optional `want_red_zone` instead of a
`no_red_zone` bool. The default is decided by a call to
`target_util.hasRedZone`.
* When creating a Clang command line, put -mred-zone on the command
line if we are forcing it to be enabled.
* Update update_clang_options.zig with respect to the recent {s}/{} format changes.
* `zig cc` integration with red zone preference.
Previously Zig would need to recompile runtime libs if you changed the
values of --strip or -O. Now, unless the `debug_compiler_runtime_libs`
flag is set (which is currently not exposed to the CLI), Zig will always
choose ReleaseFast or ReleaseSmall for compiler runtime libraries.
When the main application chooses ReleaseFast or ReleaseSmall, that
value is propagated to compiler runtime libraries. Otherwise a decision
is made based on the target, which is currently ReleaseSmall for
freestanding WebAssembly and ReleaseFast for everything else.
Ultimately the purpose of this commit is to have Debug and ReleaseSafe
builds of applications still get optimized builds of, e.g. libcxx and
libunwind, as well as to spend less time unnecessarily rebuilding compiler
runtime libraries.
See #5854
Some tiny tweaks too:
* Use `wasm-freestanding-musl` instead of `wasm32-freestanding-musl`,
making it pointer-size-agnostic.
* Fix trying to build non-existent wasm musl start files.
* std.log: still print error messages in ReleaseSmall builds.
- when start code gets an error code from main, it uses std.log.err
to report the error. this resulted in a test failure because
ReleaseSmall wasn't printing `error: TheErrorCode` when an error
was returned from main. But that seems like it should keep working.
So I changed the std.log defaults. I plan to follow this up with a
proposal to change the names of and reduce the quantity of the
log levels.
* warning emitted when using -femit-h when using stage1 backend; fatal
log message when using -femit-h with self-hosted backend (because the
feature is not yet available)
* fix double `test-cli` build steps in zig's build.zig
* update docgen to use new CLI
* translate-c uses `-x c` and generates a temporary basename with a
`.h` extension. Otherwise clang reports an error.
* --show-builtin implies -fno-emit-bin
* restore the compile error for using an extern "c" function without
putting -lc on the build line. we have to know about the libc
dependency up front.
* Fix ReleaseFast and ReleaseSmall getting swapped when passing the
value to the stage1 backend.
* correct the zig0 CLI usage text.
* update test harness code to the new CLI.
