When native-compiling, gcc will install libraries into:
/nix/store/...-$targetConfig-gcc-$version-lib/lib
When cross-compiling, gcc will install libraries into:
/nix/store/...-$targetConfig-gcc-$version-lib/$targetConfig
When cross-compiling, we intended to create a link from $lib/lib to
$lib/$targetConfig, so that downstream users can always safely
assume that "${lib.getLib stdenv.cc.cc}/lib" is where the gcc
libraries are, regardless of whether `stdenv.cc.cc` is a cross
compiler or a native compiler.
Unfortunately, there were two problems with how we were trying to
create these links:
1. The link would be created only when `enableLibGccOutput==true`
2. The link was being created from the incorrect source
`$lib/lib/lib` instead of `$lib/lib`.
Both of these mistakes are my fault. This commit corrects them by
creating the link using `ln -Ts` (which is more predictable) and by
creating the link from `gcc/common/builder.nix` rather than from
`gcc/common/libgcc.nix`.
The rest of our gcc expression prepends "${targetPlatform.config}-"
to paths and binaries if `hostPlatform!=targetPlatform`. The
`libgcc.nix` expression was using
'hostPlatform.config!=targetPlatform.config`, which caused it to
look in the wrong place when moving files. This commit corrects that.
Cross-compiled binaries currently end up with two different libgcc
outpaths in their closure. This is harmless, but confusing.
The two libgccs are:
- One of them is the "first" targetPlatform libgcc, which is built
by the "first" cross-compiler. This "first libgcc" and "first
compiler" are used to build the targetPlatform glibc.
- Once glibc is built, we *rebuild* the cross-compiler, since gcc
can't enable most of its features unless you give it an
already-compiled targetPlatform glibc. When this "second"
compiler is built, it also builds an extra copy of libgcc.
This commit discards the second, extra libgcc, and instead puts a
reference to the first (correct) libgcc into the "second compiler"
`.passthru.libgcc`, so that anybody expecting `stdenv.cc.cc.libgcc`
to exist will still find it there.
Closes#249680
msvcrt is only one of the libcs in MinGW. We therefore
replace explictly testing for msvcrt with the isMinGW
predicate. This lays the foundation for ucrt64 support.
We want a `libgcc_s.so` to be built by the first stage
cross-compiler (withoutTargetLibc), since that is the compiler which
will compile the target libc.
This commit accomplishes that, by making three changes:
1. Replacing the `targetPlatform.libc == "msvcrt" &&` conditional
with `enableShared`, so that the code which cross-build
`libgcc_s.so` is used for all cross compilers capable of emitting
shared libraries.
2. Removing the `targetPlatform == hostPlatform` guard from the code
which produces the `libgcc` output.
3. Looking for build products in in "lib/${targetPlatform.config}/"
rather than "lib/", so we will find them when cross compiling.
This commit deduplicates libgcc-related boilerplate which appears in
every version of our gcc expression, by moving it into libgcc.nix.
I will be submitting a separate PR which changes this boilerplate,
but that PR will be much easier to review if I can make the change
in just one place.
Meanwhile, *this* commit has no effect on eval:
$ for A in 10 11 12 13 4.8 4.9 6 7 8 9; do nix-instantiate . -A gcc$(echo $A | tr -d .); done 2>/dev/null | sort | tee before
/nix/store/1a37lnzpnz0dhm3lphiy2gcdrxgqa7ma-gcc-wrapper-4.8.5.drv
/nix/store/5szdivc8il0c3g94dq4wqnq5j77a9h6p-gcc-wrapper-11.4.0.drv
/nix/store/bmmc717wmnp1j2xkd3if5dfxicnflvn5-gcc-wrapper-7.5.0.drv
/nix/store/fc1ggpixv3wqcazchhl2hnn5zl5ds30l-gcc-wrapper-13.1.0.drv
/nix/store/j9c2b20w35r3ag5nxmklhagbwsgjhds2-gcc-wrapper-4.9.4.drv
/nix/store/nq7q57bxmsk2g457wr4b9449as3f216w-gcc-wrapper-12.3.0.drv
/nix/store/sqmkkfapzykapcs4azvxm83n786ga7q1-gcc-wrapper-10.4.0.drv
/nix/store/vxnz30i23mkl4ldsq485kxn7q0p2y4nf-gcc-wrapper-8.5.0.drv
/nix/store/yfhv0bv15cg5kj2xsb9fcgb6pdlw42v0-gcc-wrapper-6.5.0.drv
/nix/store/yi5gr75pb6kddnll10jg25hhndhkba7s-gcc-wrapper-9.5.0.drv
$ for A in 10 11 12 13 4.8 4.9 6 7 8 9; do nix-instantiate . -A gcc$(echo $A | tr -d .); done | sort | tee after
/nix/store/1a37lnzpnz0dhm3lphiy2gcdrxgqa7ma-gcc-wrapper-4.8.5.drv
/nix/store/5szdivc8il0c3g94dq4wqnq5j77a9h6p-gcc-wrapper-11.4.0.drv
/nix/store/bmmc717wmnp1j2xkd3if5dfxicnflvn5-gcc-wrapper-7.5.0.drv
/nix/store/fc1ggpixv3wqcazchhl2hnn5zl5ds30l-gcc-wrapper-13.1.0.drv
/nix/store/j9c2b20w35r3ag5nxmklhagbwsgjhds2-gcc-wrapper-4.9.4.drv
/nix/store/nq7q57bxmsk2g457wr4b9449as3f216w-gcc-wrapper-12.3.0.drv
/nix/store/sqmkkfapzykapcs4azvxm83n786ga7q1-gcc-wrapper-10.4.0.drv
/nix/store/vxnz30i23mkl4ldsq485kxn7q0p2y4nf-gcc-wrapper-8.5.0.drv
/nix/store/yfhv0bv15cg5kj2xsb9fcgb6pdlw42v0-gcc-wrapper-6.5.0.drv
/nix/store/yi5gr75pb6kddnll10jg25hhndhkba7s-gcc-wrapper-9.5.0.drv
$ diff -u after before
$
