Repeated
CARGO_LOG=cargo::core::compiler::fingerprint=trace cargo b
show that we always rebuild because of "compat.c". Not sure why.
Let's disable this for now so we can use the cache (for test targets etc.).
We rarely attach trait methods to stdlib types so this warning is unlikely to
be a true positive It is a false positive for the methods defined in future.rs.
It's not always obvious which method is selected when it's available in the
stdlib but I haven't seen a build failure yet. So let's disable the warning.
In future we might be able suppress it per method, see Rust issue 48919.
We often want to format and print a string to a fd, usually stdout/stderr.
In general we can't use "format!", "print!", "eprint!" etc. because they don't
know about our use of WString where we encode of invalid Unicode characters
in the private use area.
Instead we use "wwrite_to_fd()".
Since we unfortunately don't have a "wformat!()" yet, we use "sprintf!()"
to create a formatted wstring to pass to "wwrite_to_fd()".
Add "printf!" and "eprintf!" to stand in for "print!" and "eprint!".
For printing to files other than stdout and stderr, keep "fwprintf!" but
drop the "w" since our "sprintf!" always produces wide strings.
Replace "fputws" with "fprintf" though we could also use "wwrite_to_fd"
if performance matters.
Unlike std::io::stdout(), we don't use locking yet.
Remaining work:
- There are more places where we use \be?print(ln)?!
Usually we print strings that are guaranteed to be valid UTF-8, but not
always. We should probably make all of them respect our WString semantics
but preferrably keep using the native Rust format strings (#9948).
- I think flog.rs currently uses String so it won't handle invalid Unicode
characters. We should probably fix this as well.
This test wants to generate a U+FDD2 to see it is not mishandled.
To do so, we tried to use sh, which on my system is bash and can do
`$'\ufdd2'`.
Unfortunately on other systems it might be dash, which won't do that.
Since I don't know of a good no-dependency portable way to generate
this (I dimly remember python3 being a shim on some systems, so I do
not want to invoke it here), we'll just use our own printf.
Which is a worse test, we control both parts, but it'll do.
Fixes#10134
