This is split out from the LTO change. It's needed by the LTO build so
that we can easily build these files in non-LTO mode, since they satisfy
calls emitted by LLVM codegen after LTO.
Use wasm's builtin min and max operators to implement libc `fmin`,
`fmax, `fminf`, and `fmaxf`, by handling the NaN cases explicitly.
Credit to https://github.com/emscripten-core/emscripten/pull/9689
for spotting this opportunity!
wasi-libc's copy of libpreopen has evolved so many local changes that
it's no longer worth keeping the upstream code structure and marking
changes with __wasilibc_unmodified_upstream.
This PR merges the source files into a single file, removes all
__wasilibc_unmodified_upstream code, eliminates the ability to
allocate multiple preopen lists, eliminates the need for
__wasilibc_init_preopen, eliminates the non-standard eaccess, and
makes several other cleanups. It also enables NDEBUG so that internal
assertions are disabled in release builds.
utime.h, sysmacros.h, and libintl.h are all currently unsupported.
Removing them helps programs that autodetect features based on the
existence of headers.
* Link `populate_environ` only if we actually need environment variables.
This avoids linking in the environment variable initialization code,
and the __wasi_environ_sizes_get and __wasi_environ_get imports, in
programs that don't use environment variables.
This also removes the "___environ" (three underscores) alias symbol,
which is only in musl for backwards compatibility.
* Switch to //-style comments.
* If malloc fails, don't leave `__environ` pointing to an uninitialized buffer.
* Fix a memory leak if one malloc succeeds and the other fails.
* Use calloc to handle multiplication overflow.
This also handles the NULL terminator.
* Don't initialize __environ until everything has succeeded.
* Avoid leaking in case __wasi_environ_get fails.
* Handle overflow in the add too.
* Add #include <stdlib.h> for malloc etc.
* If the environment is empty, don't allocate any memory.
* Remove -fno-builtin.
-fno-builtin suppresses optimizations such as turning calls to `sqrt`
or `fabs` into `f64.sqrt` or `f64.abs` instructions inline. Libc code
itself benefits from these optimizations.
I originally added this flag because historically it was needed when
building libc to avoid the compiler pattern-matching the body of memcpy
into a memcpy call, however clang no longer requires this.
* Expand the comment about why we use USE_DL_PREFIX in dlmalloc.
We already use the compiler's versions of these; this just moves from
having libc #include_next them to having libc just omit them entirely,
which is simpler.
This removes the special code to define musl's include guard, however
I originally added that when I was still working out how WASI's stddef.h
would interact with other code. I believe it's no longer important.
For functions like sqrt, fabs, and others, use the builtin functions,
which provide single-instruction implementations, rather than using
musl's portable implementations.
My understanding is that these dummy libs represent libraries who's
contents, under musl, live in libc itself rather than being split out
into separate libs.
libc++/libc++abi are not provided my musl so doesn't make sense to
pretend that we provide them.
These functions aren't specific to the underlying system call interface,
so they don't need to be in the "bottom half".
This also fixes src/functional/inet_pton.c and
src/regression/inet_pton-empty-last-field.c in musl's libc-test.
Remove build rules for $(SYSROOT) and $(SYSROOT_INC). The latter
becomes `include_dirs`. The former is not needed, instead just add
startup_files to the finish rule.
Most of the changes are in threads, TLS, dynamic linking, and other
features wasi doesn't yet use, but there are some bug fixes in code
wasi does use.
atanl.c - local changes no longer needed as they've now landed upstream.
include/alltypes.h.in - Upstream now makes FILE a complete type in
pre-C11 mode. For WASI, this level of pre-C11 strictness isn't as
important, and having multiple incompatible definitions of _IO_FILE
that are kept separate only by clever use of translation unit
boundaries can confuse some tools, so stick with the incomplete type.
And clean up various stale declarations and macros that this turned up.
In particular:
- Don't install pthread.h or aio.h in THREAD_MODEL=single mode.
- Don't define mkstemp and friends, since WASI currently has no support for
temporary directories.
Whether these are defined or not depends on the version of clang in use,
and they're not that important at this time, so for now just ignore them
for the purposes of this testing output.
This populates the repo with a very minimal set of files. This is just
enough to set out a basic outline. Hopefully as we move forward we'll
be replacing many of these parts, but this is just something basic to
get things started.
This tree isn't really usable yet, as it doesn't yet have an easy way
to obtain a compiler-rt/libgcc build.
Dan Gohman
Sam Clegg
Till Schneidereit
Jakub Konka
Jakub Konka
Pat Hickey
Petr Penzin