Previously the toolchain wrappers used to assume the zig_lib_dir is
always in "lib". However, it depends on the OS: macos-x86_64 and
linux-aarch64 have it in "lib/zig".
Update the wrapper scripts to reflect that.
Zig does not always share `libc++.a` and the glibc shims. We have observed
to be caused for 2 reasons:
- For some commands Go `chdir`s to `/tmp/`. This causes `ZIG_LIB_DIR` to be
absolute, which blows the cache key to find the right `libc++.a` (because Zig
thinks we are using a different lib dir to compile libc++). This is currently
worked around in `toolchain/defs.bzl` by overfitting to Go and returning
early from that particular invocation.
- Sometimes Bazel's sandbox messes up Zig's cache keys. If one runs without the
sandbox (`--spawn_strategy=standalone`), the cache hit rate and thus the
build time are much better.
This is actively investigated. I am adding `--spawn_strategy=standalone`
to CI to see the speedup that it provides. I will rollback it later.
Go ignores CFLAGS for some commands. That causes unnecessary build of
glibc shims (and libc++.a).
In the GCC days cross-compiler toolchains used to expose a "tool" per
architecture. Let's do the same here. Then Go cannot cheat with skipping
CFLAGS which we normally *always* expect.
The wrapper code is getting gnarly, I know. But it still fits in my head
somehow, so we can still keep adding to it.
'common' is not a thing in Windows; but it needs to be defined.
This makes v1.0.0-rc3 broken for Windows, and not useful (yet) for
anyone else but me. Revert the README update too.
Empirically these need to come from most specfic to least specific.
The error message is as follows:
In file included from test/c/main.c:1:
In file included from external/zig_sdk/lib/libcxx/include/stdio.h:107:
In file included from external/zig_sdk/lib/libc/include/generic-glibc/stdio.h:38:
external/zig_sdk/lib/libc/include/generic-glibc/bits/types.h:139:3: error:
# error
^
external/zig_sdk/lib/libc/include/generic-glibc/bits/types.h:145:1: error: unknown type name '__STD_TYPE'
__STD_TYPE __DEV_T_TYPE __dev_t; /* Type of device numbers. */
Dissected `generic-glibc/bits/types.h:#error`:
#if __WORDSIZE == 32
<...>
# define __STD_TYPE __extension__ typedef
#elif __WORDSIZE == 64
<...>
# define __STD_TYPE typedef
#else
# error
#endif
So we do not have the `__WORDSIZE`. Where does that come from? Probably from a
directory that has an `x86_64` in it. How does that get included? Let's start
with `lib/libcxx/include/stdio.h`:
16 #include_next <stdio.h>
Now previously our `c++` command line looked like this:
external/zig_sdk/tools/c++ \
<...>
-Iexternal/zig_sdk/lib/include \
-Iexternal/zig_sdk/lib/libcxx/include \
-Iexternal/zig_sdk/lib/libcxxabi/include \
-Iexternal/zig_sdk/lib/libunwind/include \
-Iexternal/zig_sdk/lib/libc/include/generic-glibc \
-Iexternal/zig_sdk/lib/libc/include/any-linux-any \
-Iexternal/zig_sdk/lib/libc/include/x86_64-linux-gnu \
-Iexternal/zig_sdk/lib/libc/include/x86_64-linux-any \
-Iexternal/zig_sdk/lib/libc/include/x86-linux-any \
-Iexternal/zig_sdk/glibc-hacks \
<...>
So the next place it will find `stdio.h` is in `generic-glibc`, which already
uses the `__WORDSIZE`. If we make the "next" include to be the arch-specific
one instead of the generic-glibc, things start compiling again.
Fix the same fo musl.
The user may want to build with `--sandbox_tmpfs_path=/tmp`, in which
case the Zig cache will not be shared between sandboxes, massively
slowing down the build. With this feature, the user can pass flags
like `--repo_env=BAZEL_ZIG_CC_CACHE_PREFIX=$HOME/.cache/bazel-zig-cc`
together with `--sandbox_writable_path=$HOME/.cache/bazel-zig-cc` to
put the cache somewhere else which can be shared between sandboxes.
As it expects Bash to be at `/bin/bash`, the current implementation
fails to execute on NixOS, given that there bash is in a non-standard
path (i.g. `/nix/store/<hash>-bash-interactive-<version>/bin/bash`).
This patch specifically changes `/bin/bash` paths to use `/usr/bin/env bash`,
which should give the correct path in every Unix system.
Signed-off-by: Luis Holanda <luiscmholanda@gmail.com>
Now that the toolchain supports multiple mirrors, we can have more
robust defaults: try ziglang.org first, then dl.jakstys.lt when that one
removes the build we rely on.
This will make builds less prone to inevitable failures of my home
server.
`zig cc` emits `--gc-sections` for the linker, which is incompatbile
with what CGo thinks about linking.
This commit adds a workaround: it will add `--no-gc-sections` to the
linking step if the command is not specified (falling back to the
default behavior of gcc/clang).
Related: https://github.com/golang/go/issues/52690
