Auto merge of rust-lang#102530 - cuviper:upgrade-i586-gnu, r=pietroalbini

Upgrade dist-i586-gnu-i586-i686-musl to ubuntu:22.04

The system GCC 5 in ubuntu:16.04 will be too old to compile LLVM 16, so
we need an upgrade. To avoid raising the minimum glibc requirements for
`i586-unknown-linux-gnu`, this target is converted to a crosstool-ng
toolchain, *relaxing* it to the same Linux 3.2 / glibc 2.17 minimum we
use elsewhere. The musl targets still use Ubuntu's system toolchain, but
this doesn't have the same compatibility concerns.

Author: bors

src/ci/docker/README.md

@@ -230,6 +230,22 @@ For targets: `aarch64-unknown-linux-gnu`
 - C compiler > gcc version = 8.3.0
 - C compiler > C++ = ENABLE -- to cross compile LLVM
 
+### `i586-linux-gnu.config`
+
+For targets: `i586-unknown-linux-gnu`
+
+- Path and misc options > Prefix directory = /x-tools/${CT\_TARGET}
+- Path and misc options > Patches origin = Bundled only
+- Target options > Target Architecture = x86
+- Target options > Architecture level = i586
+- Target options > Target CFLAGS = -Wa,-mrelax-relocations=no
+- Operating System > Target OS = linux
+- Operating System > Linux kernel version = 3.2.101
+- Binary utilities > Version of binutils = 2.32
+- C-library > glibc version = 2.17.0
+- C compiler > gcc version = 8.3.0
+- C compiler > C++ = ENABLE
+
 ### `powerpc-linux-gnu.config`
 
 For targets: `powerpc-unknown-linux-gnu`

src/ci/docker/host-x86_64/dist-i586-gnu-i586-i686-musl/Dockerfile

@@ -1,5 +1,6 @@
-FROM ubuntu:16.04
+FROM ubuntu:22.04
 
+ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update && apt-get install -y --no-install-recommends \
   g++-multilib \
   make \
@@ -17,6 +18,25 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libssl-dev \
   pkg-config
 
+COPY scripts/cross-apt-packages.sh /scripts/
+RUN sh /scripts/cross-apt-packages.sh
+
+COPY scripts/crosstool-ng-1.24.sh /scripts/
+RUN sh /scripts/crosstool-ng-1.24.sh
+
+COPY scripts/rustbuild-setup.sh /scripts/
+RUN sh /scripts/rustbuild-setup.sh
+WORKDIR /tmp
+
+COPY host-x86_64/dist-i586-gnu-i586-i686-musl/i586-linux-gnu.config \
+     host-x86_64/dist-i586-gnu-i586-i686-musl/build-i586-gnu-toolchain.sh \
+     /tmp/
+RUN su rustbuild -c ./build-i586-gnu-toolchain.sh
+ENV PATH=$PATH:/x-tools/i586-unknown-linux-gnu/bin
+ENV \
+    CC_i586_unknown_linux_gnu=i586-unknown-linux-gnu-gcc \
+    AR_i586_unknown_linux_gnu=i586-unknown-linux-gnu-ar
+
 WORKDIR /build/
 COPY scripts/musl.sh /build/
 RUN CC=gcc CFLAGS="-m32 -Wa,-mrelax-relocations=no" \
@@ -27,17 +47,20 @@ RUN CC=gcc CFLAGS="-m32 -Wa,-mrelax-relocations=no" \
     bash musl.sh i586 --target=i586 && \
     rm -rf /build
 
+# FIXME: musl really shouldn't be linking libgcc_s.so, as it's linked to glibc,
+# but it's required by src/test/ui/proc-macro/crt-static.rs. Ubuntu:16.04 gcc-5
+# had libgcc_s.so as a symlink to the absolute libgcc_s.so.1, but now it's an
+# ld-script that expects to find libgcc_s.so.1 in the library search path.
+# See also https://github.com/rust-lang/rust/issues/82521
+RUN ln -s /usr/lib32/libgcc_s.so.1 /musl-i686/lib/
+
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
-COPY scripts/cmake.sh /scripts/
-RUN /scripts/cmake.sh
-
 ENV RUST_CONFIGURE_ARGS \
       --musl-root-i586=/musl-i586 \
       --musl-root-i686=/musl-i686 \
-      --disable-docs \
-      --set llvm.allow-old-toolchain
+      --disable-docs
 
 # Newer binutils broke things on some vms/distros (i.e., linking against
 # unknown relocs disabled by the following flag), so we need to go out of our

src/ci/docker/host-x86_64/dist-i586-gnu-i586-i686-musl/build-i586-gnu-toolchain.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -ex
+
+hide_output() {
+  set +x
+  on_err="
+echo ERROR: An error was encountered with the build.
+cat /tmp/build.log
+exit 1
+"
+  trap "$on_err" ERR
+  bash -c "while true; do sleep 30; echo \$(date) - building ...; done" &
+  PING_LOOP_PID=$!
+  "$@" &> /tmp/build.log
+  rm /tmp/build.log
+  trap - ERR
+  kill $PING_LOOP_PID
+  set -x
+}
+
+mkdir build
+cd build
+cp ../i586-linux-gnu.config .config
+hide_output ct-ng build
+cd ..
+rm -rf build