cc-wrapper: change cflags order from cc/crt1/libc to crt1/libc/cc

In https://github.com/NixOS/nixpkgs/issues/158042 I noticed order
mismatch as a bootstrap build failure when building x86_64-linux
against glibc-2.35 in nixpkgs (bootstrap libs has glibc-2.27):

    expand-response-params> ld: /nix/store/p4s4jf7aq6v6z9iazll1aiqwb34aqxq9-bootstrap-tools/lib/crt1.o: in function `_start':
    expand-response-params> /build/glibc-2.27/csu/../sysdeps/x86_64/start.S:101: undefined reference to `__libc_csu_fini'
    expand-response-params> ld: /build/glibc-2.27/csu/../sysdeps/x86_64/start.S:102: undefined reference to `__libc_csu_init'
    expand-response-params> collect2: error: ld returned 1 exit status

Here crt1.o from glibc-2.27 links against libc.so.6 from glibc-2.35.

This happens because ordering of `-L` (influences `libc.so` lookup) and
`-B` (influences `crt1.o` lookup) flags differs:

    expand-response-params>   -B/...-bootstrap-tools/lib
    expand-response-params>   -B/...-glibc-2.35/lib/
    ...
    expand-response-params>   -L/...-glibc-2.35/lib
    expand-response-params>   -L/...-bootstrap-tools/lib

The change makes consistent ordering of `-L`/`-B` and allows getting to
stage4 for `glibc-2.35` target.
This commit is contained in:
Sergei Trofimovich 2022-02-11 18:55:51 +00:00
parent dafecf1c6d
commit 649ebfbed6

View File

@ -33,6 +33,20 @@ NIX_CFLAGS_COMPILE_@suffixSalt@="-B@out@/bin/ $NIX_CFLAGS_COMPILE_@suffixSalt@"
# Export and assign separately in order that a failing $(..) will fail
# the script.
# Currently bootstrap-tools does not split glibc, and gcc files into
# separate directories. As a workaround we want resulting cflags to be
# ordered as: crt1-cflags libc-cflags cc-cflags. Otherwise we mix crt/libc.so
# from different libc as seen in
# https://github.com/NixOS/nixpkgs/issues/158042
#
# Note that below has reverse ordering as we prepend flags one-by-one.
# Once bootstrap-tools is split into different directories we can stop
# relying on flag ordering below.
if [ -e @out@/nix-support/cc-cflags ]; then
NIX_CFLAGS_COMPILE_@suffixSalt@="$(< @out@/nix-support/cc-cflags) $NIX_CFLAGS_COMPILE_@suffixSalt@"
fi
if [[ "$cInclude" = 1 ]] && [ -e @out@/nix-support/libc-cflags ]; then
NIX_CFLAGS_COMPILE_@suffixSalt@="$(< @out@/nix-support/libc-cflags) $NIX_CFLAGS_COMPILE_@suffixSalt@"
fi
@ -49,10 +63,6 @@ if [ -e @out@/nix-support/libcxx-ldflags ]; then
NIX_CXXSTDLIB_LINK_@suffixSalt@+=" $(< @out@/nix-support/libcxx-ldflags)"
fi
if [ -e @out@/nix-support/cc-cflags ]; then
NIX_CFLAGS_COMPILE_@suffixSalt@="$(< @out@/nix-support/cc-cflags) $NIX_CFLAGS_COMPILE_@suffixSalt@"
fi
if [ -e @out@/nix-support/gnat-cflags ]; then
NIX_GNATFLAGS_COMPILE_@suffixSalt@="$(< @out@/nix-support/gnat-cflags) $NIX_GNATFLAGS_COMPILE_@suffixSalt@"
fi