* Add short documentation to std.log.scoped and std.log.default
* Update the module documentation and example to explain the difference
between using explicit scopes, using a scoped logging namespace, and
using the default namespace
* Add a std.log.scoped function that returns a scoped logging struct
* Add a std.log.default struct that logs using the .default scope
Implementation of daurnimator's proposal:
https://github.com/ziglang/zig/issues/5943#issuecomment-669043489
Note that I named the function "scoped" instead of "scope" so as not to
clash with the scope parameter that is used everywhere; this seemed a
better solution to me than renaming the scope parameter to "s" or
"log_scope" or the like.
This makes collected stack traces omit less useful frames. For user
applications which only store a fixed number of stack frames this can
make a big difference.
`std.builtin.StackTrace` gains a `format` function.
GeneralPurposeAllocator uses `std.log.err` instead of directly printing
to stderr. Some errors are recoverable.
The test runner is modified to fail the test run if any log messages of
"err" or worse severity are encountered.
self-hosted is modified to always print log messages of "err" severity
or worse even if they have not been explicitly enabled.
This makes GeneralPurposeAllocator available on the freestanding target.
We don't pass no-omit-frame-pointer in release safe by default, so it
also makes sense to not try to collect stack trace frames by default in
release safe mode.
This makes `@returnAddress()` return 0 for WebAssembly (when not using
the Emscripten OS) and avoids trying to capture stack traces for the
general purpose allocator on that target.
The high level Allocator interface API functions will now do a
`@returnAddress()` so that stack traces captured by allocator
implementations have a return address that does not include the
Allocator overhead functions. This makes `4` a more reasonable default
for how many stack frames to capture.
* std.Mutex API is improved to not have init() deinit(). This API is
designed to support static initialization and does not require any
resource cleanup. This also happens to work around some kind of
stage1 behavior that wasn't letting the new allocator mutex code
get compiled.
* the general purpose allocator now returns a bool from deinit()
which tells if there were any leaks. This value is used by the test
runner to fail the tests if there are any.
* self-hosted compiler is updated to use the general purpose allocator
when not linking against libc.
