Currently llvm-linkage mode (static vs dynamic) decides linkage mode
for system libstdc++/libc++ .
A previous commit only tested static mode for *BSD and netbsd was
reported to not work in dynamic mode.
We now special-case freebsd, openbsd, netbsd and dragonfly for dynamic
linking too.
@bitCast from integer NaN representation to float NaN resulted in
changed bits in float. This only happened with signaled NaN.
- added test for signaled NaN
- added tests for quiet NaN (for completeness)
closes#14198
- Add an assert that an exclusive lock is help to writeManifest
- Only call writeManifest in updateCObject if an exclusive lock is held
- cache: fixup test to verify hits don't take an exclusive lock, instead of writing the manifest
Can occur when trying to open a directory for iteration but the 'List folder contents' permission of the directory is set to 'Deny'.
This was found because it was being triggered during PATH searching in ChildProcess.spawnWindows if a PATH entry did not have 'List folder contents' permission, so this fixes that as well (note: the behavior on hitting this during PATH searching is to treat it as the directory not existing and therefore will fail to find any executables in a directory in the PATH without 'List folder contents' permission; this matches Windows behavior which also fails to find commands in directories that do not have 'List folder contents' permission).
Given `main.go`:
package main
import _ "os/user"
func main() {}
Compiling it to linux/arm64:
$ CGO_CFLAGS='-O0' GOOS=linux GOARCH=arm64 CGO_ENABLED=1 CC="zig cc -target aarch64-linux-gnu.2.28" go build main.go
Results in this error:
runtime/cgo(.text): unknown symbol memset in callarm64
runtime/cgo(.text): unknown symbol memset in callarm64
runtime/cgo(.text): relocation target memset not defined
In the midst of intermediate compilations files we can see this commmand:
ld.lld -o _cgo_.o <...> /tmp/go-build206961058/b043/_x009.o <...> ~/.cache/zig/.../libcompiler_rt.a <...> ~/.cache/.../libc.so.6
`_x009.o` needs memset:
$ readelf -Ws ./b043/_x009.o | grep memset
22: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND memset
Both `libcompiler_rt.a` and `libc.so.6` provide it:
$ readelf -Ws ~/.cache/zig/.../libcompiler_rt.a | grep memset
870: 0000000000000000 318 FUNC WEAK DEFAULT 519 memset
$ readelf -Ws ~/.cache/zig/.../libc.so.6 | grep -w memset
476: 000000000001d34c 0 FUNC GLOBAL DEFAULT 7 memset@@GLIBC_2.2.5
Since `libcompiler_rt.a` comes before libc in the linker line, the
resulting `_cgo_.o` still links to a weak, unversioned memset:
$ readelf -Ws ./b043/_cgo_.o | grep -w memset
40: 000000000022c07c 160 FUNC WEAK DEFAULT 14 memset
719: 000000000022c07c 160 FUNC WEAK DEFAULT 14 memset
Since the final linking step is done by Golang's linker, it does not
know of `libcompiler_rt.a`, and fails to link with the error message
above. However, Go linker does recognize memset from glibc. If we
specify an `-lc` equivalent before the `libcompiler_rt.a`, it will link
to memset from libc:
$ readelf -Wa ./b043/_x009.o |grep memset
14: 0000000000000000 0 FUNC GLOBAL DEFAULT UND memset@GLIBC_2.17 (2)
157: 0000000000000000 0 FUNC GLOBAL DEFAULT UND memset@GLIBC_2.17
... and then `main.go` will compile+link successfully.
Why doesn't Go linker take memset from glibc? An educated guess: Go
determines whether to link with glibc from what the program asks (I
presume `.dynsym`). Since `memset` is no longer attributed to glibc, Go
skips linking to glibc altogether.
Bonus question: curious why `-O0` is necessary? Because when
optimizations are enabled (the default), the C compiler replaces
`memset` function call with plain `stp` instructions (on aarch64).
This helps prevent errors related to undefined pointers being passed
through to some OS apis when slices have 0 length.
Tests have also been added to catch these cases.
The PCG32 fill function seems to have been copy-pasted from code using u64, so requesting `n` bytes where `(n & 7) > 4` bytes would cause the last few bytes to be all 0.
This fixes a class of bugs on macOS where a segfault happening in
a loaded dylib with no debug info would cause a panic in the panic
handler instead of simply noting that the dylib has no valid debug
info via `error.MissingDebugInfo`. An example could be code linking
some system dylib and causing some routine to segfault on say invalid
pointer value, which should normally cause Zig to print an incomplete
stack trace anchored at the currently loaded image and backtrace all
the way back to the Zig binary with valid debug info. Currently, in
a situation like this we would trigger a panic within a panic.
We definitely want a shared lock on a cache hit. Without this, we get a
deadlock when Zig is asked to compile the same C source file multiple
times as part of the same compilation.
This is a partial revert of 8ccb9a6ad327a4d7fbc321b33d4aa66a27a1f5ee.
cc @kcbanner
- C compilation flows didn't hold an exclusive lock on the cache manifest file when writing to it in all cases
- On windows, explicitly unlock the file lock before closing it
Before this commit, I observe a crash from this abiSize call because the
element type is a struct that is not yet resolved. This is triggered by
running the behavior tests with -ofmt=c -target x86_64-windows.
This is a partial revert of 0d533433e21621177fb291e2a4901bee11834501,
which regressed this behavior. The idea here is to avoid aliases, which
happens when the same function is exported with multiple names. The
problem with aliases is that weak aliases don't seem to work, causing
symbol collisions when multiple of the same symbol are provided, despite
the desired behavior that weak symbols are overridden.
In this case we export redundant functions with different names. Thanks
to -ffunction-sections, the unused functions will be garbage-collected
at link time. This leaves us with the best of both worlds: Zig's
compiler-rt will provide both sets of symbols, and it will be
binary-compatible with different compilers that expect different names,
while still resulting in binaries without garbage.
Override the cache directories because they won't actually help other CI
runs which will be testing alternate versions of zig, and ultimately
would just fill up space on the hard drive for no reason.
In practice we did see one of the CI servers fill up too many files
inside ~/.cache/zig, which caused certain file system operations to
start returning ENOSPC, despite the hard drive having plenty of space
left.
