Merge #987

987: Link to libgcc for `armv5te-unknown-linux-musleabi` target. r=Emilgardis a=Alexhuszagh

Fixes missing sync builtins required for libraries such as OpenSSL, specifically, the `__sync_X_and_fetch` builtins.

Closes #367.
Improves documentation related to #906.

Co-authored-by: Alex Huszagh <ahuszagh@gmail.com>

Author: bors[bot]

.changes/987.json

@@ -0,0 +1,5 @@
+{
+    "type": "fixed",
+    "description": "link to libgcc for `armv5te-unknown-linux-musleabi` to fix missing `__sync_X_and_fetch` builtins.",
+    "issues": [367]
+}

docker/Dockerfile.mips64-unknown-linux-muslabi64

@@ -21,15 +21,15 @@ ENV CROSS_MUSL_SYSROOT=/usr/local/mips64-linux-musl
 COPY musl-symlink.sh /
 RUN /musl-symlink.sh $CROSS_MUSL_SYSROOT mips64
 RUN mkdir -p $CROSS_MUSL_SYSROOT/usr/lib64
-# needed for the C/C++ runner
+# needed for the C/C++ runners
 RUN ln -s $CROSS_MUSL_SYSROOT/usr/lib/libc.so $CROSS_MUSL_SYSROOT/usr/lib64/libc.so
 RUN ln -s $CROSS_MUSL_SYSROOT/usr/lib/libc.so.1 $CROSS_MUSL_SYSROOT/usr/lib64/libc.so.1
 
-COPY mips64-linux-muslabi64-gcc.sh /usr/bin/
+COPY mips64-linux-musl-gcc.sh /usr/bin/
 
 COPY qemu-runner base-runner.sh /
 
-ENV CARGO_TARGET_MIPS64_UNKNOWN_LINUX_MUSLABI64_LINKER=mips64-linux-muslabi64-gcc.sh \
+ENV CARGO_TARGET_MIPS64_UNKNOWN_LINUX_MUSLABI64_LINKER=mips64-linux-musl-gcc.sh \
     CARGO_TARGET_MIPS64_UNKNOWN_LINUX_MUSLABI64_RUNNER="/qemu-runner mips64" \
     CC_mips64_unknown_linux_muslabi64=mips64-linux-musl-gcc \
     CXX_mips64_unknown_linux_muslabi64=mips64-linux-musl-g++ \

docker/aarch64-linux-musl-gcc.sh

@@ -14,12 +14,12 @@ main() {
     local minor=
     minor=$(echo "$release" | cut -d '.' -f2)
 
-    if (( minor >= 48 )); then
+    if (( minor >= 48 )) || [[ $# -eq 0 ]]; then
         # no workaround
-        aarch64-linux-musl-gcc "${@}"
+        exec aarch64-linux-musl-gcc "${@}"
     else
         # apply workaround
-        aarch64-linux-musl-gcc "${@}" -lgcc
+        exec aarch64-linux-musl-gcc "${@}" -lgcc -static-libgcc
     fi
 }
 

docker/arm-linux-musleabi-gcc.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# this linker wrapper works around the missing sync `sync_X_and_fetch`
+# routines. this affects rust versions with compiler-builtins <= 0.1.77,
+# which has not yet been merged into stable. this requires the `-lgcc`
+# linker flag to provide the missing builtin.
+# https://github.com/rust-lang/compiler-builtins/pull/484
+
+set -x
+set -euo pipefail
+
+main() {
+    if [[ $# -eq 0 ]]; then
+        exec arm-linux-musleabi-gcc "${@}"
+    else
+        exec arm-linux-musleabi-gcc "${@}" -lgcc -static-libgcc
+    fi
+}
+
+main "${@}"

docker/mips64-linux-musl-gcc.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# this linker wrapper works around the missing soft-fp routine __trunctfsf2
+# this affects rust versions with compiler-builtins <= 0.1.77,
+# which has not yet been merged into stable. this requires the `-lgcc`
+# linker flag to provide the missing builtin.
+# https://github.com/rust-lang/compiler-builtins/pull/483
+
+set -x
+set -euo pipefail
+
+main() {
+    if [[ $# -eq 0 ]]; then
+        exec mips64-linux-musl-gcc "${@}"
+    else
+        exec mips64-linux-musl-gcc "${@}" -lgcc -static-libgcc
+    fi
+}
+
+main "${@}"