This commit allows `gccCrossStageStatic` to build dynamically-linked
libraries. Since is no longer restricted to building static
libraries its name is no longer appropriate, and this commit also
renames it to the more-accurate `gccWithoutTargetLibc`.
By default, you can't build a gcc that knows how to create dynamic
libraries unless you have already built the targetPlatform libc.
Because of this, our gcc cross-compiler is built in two stages:
1. Build a cross-compiler (gccCrossStageStatic) that can build
only static libraries.
2. Use gccCrossStageStatic to compile the targetPlatform libc.
3. Use the targetPlatform libc to build a fully-capable cross
compiler.
You might notice that this pattern looks very similar to what we do
with `xgcc` in the stdenv bootstrap. Indeed it is! I would like to
work towards getting the existing stdenv bootstrap to handle cross
compilers as well. However we don't want to cripple `stdenv.xgcc`
by taking away its ability to build dynamic libraries.
It turns out that the only thing gcc needs the targetPlatform libc
for is to emit a DT_NEEDED for `-lc` into `libgcc.so`. That's it!
And since we don't use `gccCrossStageStatic` to build anything other
than libc, it's safe to omit the `DT_NEEDED` because that `libgcc`
will never be loaded by anything other than `libc`. So `libc` will
already be in the process's address space.
Other people have noticed this; crosstool-ng has been using this
approach for a very long time:
36ad0b17a7/scripts/build/cc/gcc.sh (L638-L640)
The 4aa95e3312 commit added support for
aarch64-darwin but also ignored platform flags if the build platform
is aarch64-darwin. This leads to confusing errors such as
`pkgsCross.raspberryPi` packages compiled with soft-float even though
the platform supports hard-float (and is built as such on other
platforms).
The correct way to ignore platform flags is to check `targetPlatform`,
not the build platform. This change fixes that.
While we're here, tigthen the special-case to cover only the problematic
flags: `-with-cpu` and `-with-arch`.
In 6812dd98c4 I mistakenly had the
implication order reversed. This commit corrects that mistake.
The original assertion (which is correct) was the following, which
asserts that if you enable the GDB plugin, you must enable plugins
generally (there is shared infrastructure):
```
assert enableGdbPlugin -> enablePlugin;
```
When the option name was changed to `disableGdbPlugin`, I
incorrectly wrote:
```
assert disableGdbPlugin -> enablePlugin;
```
And then again incorrectly wrote:
```
assert disableGdbPlugin -> !enablePlugin;
```
This commit uses the correct equivalent for the first statement,
which is the contrapositive:
```
assert !enablePlugin -> disableGdbPlugin;
```
This commit adds an option `disableGdbPlugin` which controls whether
or not the plugin *for* GDB will be built. This plugin contains a
copy of `gcc`.
The configure flag that this option controls is called
`--disable-libcc1`. This flag name is slightly confusing: it is
used only by GDB (and apparently unmaintained), yet the flag name
does not mention GDB. This is why the option name is different from
the configure flag name.
The primary motivation for this commit is to allow the following PR
(which is not yet merged) to pass `--disable-libcc1` when building
the final native (build=host=target) compiler as part of the stdenv
bootstrap:
https://github.com/NixOS/nixpkgs/pull/209870
We need to `--disable-libcc1` in this scenario because gcc's build
machinery links `libcc1` against the `libstdc++` that is part of the
*compiler used to compile gcc*, rather than against the `libstdc++`
that is built *by* gcc. In an FHS distribution this distinction is
not terribly important because dynamically linked libraries are
late-bound (ld.so resolution). However in nixpkgs this causes a
reference back to the bootstrapFiles to leak all the way through to
the final stdenv.
More details can be found in the comment in
`pkgs/stdenv/linux/default.nix` of the PR linked above.
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
On a native (host==build==target) build, `${with_build_sysroot}` can
be omitted. In that case, the line modified by this commit is
correct.
However, if `--with-build-sysroot=` is passed to `./configure`, then
`${with_build_sysroot}` will be used, similar to the cross case, and
the headers will be taken from:
${with_build_sysroot}${native_system_header_dir}
See:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/configure.ac;h=62bc908b991ff0b700225aef32743cd3d7c4daaf;hb=HEAD#l2439
This commit adjusts the comment to account for the case where
`--with-build-sysroot` is passed to a native compiler.
I'm reasonably confident this is no longer necessary, as uclibc's
libdl.a is empty, and I can cross-build stdenv.cc.cc for
x86_64-unknown-linux-uclibc with libgomp enabled.
LLVM does not provide a drop-in replacement for as(1).
This makes it possible to build a GNU Fortran cross compiler from GNU
to LLVM — e.g. buildPackages.gfortran for
{ system = "aarch64-linux"; useLLVM = true; }
Without this change cross-built gcc fails to detect stack protector style:
$ nix log -f pkgs/stdenv/linux/make-bootstrap-tools-cross.nix powerpc64le.bootGCC | fgrep __stack_chk_fail
checking __stack_chk_fail in target C library... no
checking __stack_chk_fail in target C library... no
It happens because gcc treats search paths differently:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/configure.ac;h=446747311a6aec3c810ad6aa4190f7bd383b94f7;hb=HEAD#l2458
if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x ||
test x$build != x$host || test "x$with_build_sysroot" != x; then
...
if test "x$with_build_sysroot" != "x"; then
target_header_dir="${with_build_sysroot}${native_system_header_dir}"
elif test "x$with_sysroot" = x; then
target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-include"
elif test "x$with_sysroot" = xyes; then
target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-root${native_system_header_dir}"
else
target_header_dir="${with_sysroot}${native_system_header_dir}"
fi
else
target_header_dir=${native_system_header_dir}
fi
By passing --with-build-sysroot=/ we trick cross-case to use
`target_header_dir="${with_sysroot}${native_system_header_dir}"`
which makes it equivalent to non-cross
`target_header_dir="${with_build_sysroot}${native_system_header_dir}"`
Tested the following setups:
- cross-compiler without libc headers (powerpc64le-static)
- cross-compiler with libc headers (powerpc64le-debug)
- cross-build compiler with libc headers (powerpc64le bootstrapTools)
Before the change only 2 of 3 compilers detected libc headers.
After the change all 3 compilers detected libc headers.
For darwin we silently ignore '-syslibroot //' argument as it does not
introduce impurities.
While at it dropped mingw special case for no-libc build. Before the change
we passed both '--without-headers --with-native-system-headers-dir' for
no-libc gcc-static builds. This tricked darwin builds to find sys/sdt.h
and fail inhibid_libc builds. Now all targets avoid passing native headers
for gcc-static builds.
While at it fixed correct headers passing to
--with-native-system-headers-dir= in host != target case: we were passing
host's headers where intention was to pass target's headers.
Noticed the mismatch as a build failure on pkgsCross.powernv.stdenv.cc
on darwin where `sys/sdt.h` is present in host's headers (libSystem)
but not target's headers (`glibc`).
Co-authored-by: Adam Joseph <54836058+amjoseph-nixpkgs@users.noreply.github.com>
GCC 10 sets -fno-common by default. This broke some packages, so
when moving to GCC 10 we initially disabled this behavior. This
commit reverts that, bringing us closer to the standard and
upstream.
Co-authored-by: Sergei Trofimovich <slyich@gmail.com>
Update all usage of lib.concatStrings (lib.intersperse ...) to
lib.concatStringsSep. This produces the same result as per https://github.com/NixOS/nixpkgs/pull/135843,
however it yields a performance benefit on Nix versions that
support the builtins.concatStringsSep primop.
libgomp has been disabled on musl since musl support was first added to
nixpkgs (15d401dcfa), but seems to work
fine. Tested down to gcc 6 (gcc 4.8 already doesn't build for musl)
According to https://wiki.osdev.org/GNAT_Cross-Compiler building
libada is not possible when building a cross compiler. Unfortunately I
haven't been able to determine if this is upstream's position as well,
but sure enough disabling libada lets us build a GNAT cross compiler.
Don't rely on gcc detecting from the passed platforms which prefix to
use, but always specify the prefix nixpkgs expects (or doesn't). This
allows us to work around problems where the configure script would add
prefix where nixpkgs doesn't expect one (if `--target` was specified,
but the same as `--host`) or doesn't add one if nixpkgs expects one (if
`--target` and `--host` are the same, but we are actually cross
compiling, but the relevant parts of the platform are not encoded into
the platform config.
See also ca9be0511b.
This causes some minor ugliness during stdenv bootstrap on powerpc64le
using cross-compiled bootstrap tools. MPFR wants to use decimal floats
by default so they have to be manually disabled in the configure flags
when using cross-compiled bootstrap tools.
The lineage of this particular configure flag traces back to 2010 (!)
It was added in commit: 9b1d5353a9
I've built various cross bootstrap tools and they seem to work fine,
so I don't think this is needed anymore.
This is needed to build grub2 for powerpc64le hosts. Running powerpcle code
on powerpc64le is somewhat analogous to running multiarch i686 code on x86_64,
so it's also useful to have in general.
reasoning:
sjlj (short jump long jump) exception handling makes no sense on x86_64, it's forcably slowing programs down as it produces a constant overhead. On x86_64 we have SEH (Structured Exception Handling) and we should use that. On i686, we do not have SEH, and have to use sjlj with dwarf2. Hence it's now conditional on x86_32
This option can be used to set the “jit” language which enable the
libgccjit functionality. Also adds a “libgccjit” attr which is gcc
built with just jit enabled.
