The tool will now skip over undefined symbols. These can only occur as a result
of building musl without compiler-rt, i.e. -rtlib=none. Thanks to this, it's no
longer necessary to patch Zig's compiler-rt, nor is it necessary to maintain a
symbol blacklist.
See the updated instructions here: https://github.com/ziglang/zig/wiki/Updating-libc#updating-the-libcs-file
Additionally, the tool now produces slightly more compact output by recognizing
symbols that are defined for a single arch, for a family of arches, or only for
arches using 32-bit or 64-bit time as their primary ABI.
Finally, the tool now supports all architectures that we can emit code for, with
the single exception of x86_64-linux-muslx32. (x32 currently fails with a ton of
relocation errors, leading me to believe that it might be an LLVM or LLD bug.)
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
Adds conditional exports
- __fixkfti
- __fixunskfti
- __floattikf
- __negkf2
- __mulkc3
- __divkc3
- __powikf2
and adjusts tools/gen_stubs.zig.
From https://gcc.gnu.org/onlinedocs/gcc/Floating-Types.html:
"When long double transitions to __float128 on PowerPC in the future,
__ibm128 will remain for use in conversions between the two types."
Hence `__extendkftf2` and `__trunctfkf2` for conversion are superfluous
and only using f128 for `kf` routines is justified.
Closes#16057.
- Copy and adjust __divmodsi4 tests for __divmoddi4 and __divmodti4.
- Assuming d = a/b does not overflow (MIN/-1) or uses div by 0,
then tmp = (d * b) = (a/b * b) = a does not overflow.
=> Remove wraparound for remainder in applicable routines.
These are unused in LLVM, but in gcc used for example by rl78.
Move test files into common file, add tests for aforementioned routines
and missing ones for __lshrti3.
This was a bit trickier than it should be due to symbol conflicts with
zig's compiler-rt implementation. We attempt to use weak linkage in
our compiler-rt, but this does not seem to be working in all cases. I
manually disabled export of the problematic compiler-rt math functions
in order to cross compile musl's libc.so for all targets as input to
`tools/gen_stubs.zig`.
Other than that, this update went fairly smoothly. Quite a few
additional symbols were added to the blacklist in `tools/gen_stubs.zig`
due to recent reorganization of zig's compiler-rt.
Now it outputs libc.S which can be assembled with zig, and the small
differences per-architecture are handled with preprocessor directives.
There is also now a set of blacklisted symbols which contains
compiler-rt.
tools/gen_stubs.zig now cuts out the middle man and operates directly on
the libc.so ELF file. it outputs accurate .size directives for objects.
std.elf gains an STV enum.
