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.
These flags were added in this commit:
commit 58a04fbfec
Author: Motiejus Jakštys <motiejus@jakstys.lt>
Date: Tue Jun 15 09:10:15 2021 +0300
bump zig
I am still quite puzzled on why I did this and in such a commit: it
bumps the zig version and changes the linker flag.
Working alone, experimentation time? Probably something like this.
Anyhow, this is a good example of the real value of code reviews.
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.
While integrating the project into our Bazel workspace, we had some
problems while building protoc in an Intel MacBook.
From my testing, the issue seems to be caused by missing include path
in the toolchain configuration to the `-none` variant of the headers.
More details below.
The issue can be reproduced directly inside `bazel-zig-cc` by including
the protobuf workspace as a dependency:
+http_archive(
+ name = "com_google_protobuf",
+ sha256 = "2d9084d3dd13b86ca2e811d2331f780eb86f6d7cb02b405426e3c80dcbfabf25",
+ strip_prefix = "protobuf-3.21.1",
+ url = "https://github.com/protocolbuffers/protobuf/archive/v3.21.1.zip",
+)
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+
+protobuf_deps()
And then executing:
bazel build --platforms @zig_sdk//platform:darwin_amd64 @com_google_protobuf//:protoc
The command fails with the same error both in native compilation and
cross-compiling from Linux. The error:
ERROR: <output_base>/external/zlib/BUILD.bazel:37:11: Compiling compress.c failed: undeclared inclusion(s) in rule '@zlib//:zlib':
this rule is missing dependency declarations for the following files included by 'compress.c':
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/cdefs.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_symbol_aliasing.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/machine/limits.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/i386/limits.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/i386/_limits.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/syslimits.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/machine/types.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/i386/types.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/i386/_types.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_types/_int8_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_types/_uintptr_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/machine/_types.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_types.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/machine/endian.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/i386/endian.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/libkern/_OSByteOrder.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/libkern/i386/_OSByteOrder.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_types/_fd_def.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/Availability.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/AvailabilityInternal.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_attr_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_cond_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_condattr_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_rwlock_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_rwlockattr_t.h'
'<output_base>/external/zig_sdk/lib/libc/include/x86_64-macos.10-none/sys/_pthread/_pthread_t.h'
Target @com_google_protobuf//:protoc failed to build
(<output_base> replaced manually to keep the description sane)
Note that the specific rule included in the error message will vary due
to parallelism, but the error is always the same and the missing paths
always have the same prefix (up to `x86_64-macos.10-none`).
After applying the patch, we confirmed that both native and cross compilations
works as expected and can properly build protoc.
Signed-off-by: Luis Holanda <luiscmholanda@gmail.com>
This patch continues the work to support NixOS and others non-FHS
distributions by replacing instances of `/bin/bash` with
`/usr/bin/env bash`, which works correctly in more systems than the
former.
Signed-off-by: Luis Holanda <luiscmholanda@gmail.com>
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>
