linux: add MUSL

We don't do anything with it yet. I'd like to experiment with
compiling against musl so we don't incur a glibc run-time
dependency.

Author: indygreg

cpython-linux/Makefile

@@ -11,12 +11,17 @@ COMMON_DEPENDS := \
 
 PLATFORM := linux64
 
-TOOLCHAIN_DEPENDS := \
+BASE_TOOLCHAIN_DEPENDS := \
     $(OUTDIR)/binutils-linux64.tar \
     $(OUTDIR)/gcc-linux64.tar \
     $(OUTDIR)/clang-linux64.tar \
     $(NULL)
 
+TOOLCHAIN_DEPENDS := \
+    $(BASE_TOOLCHAIN_DEPENDS) \
+    $(OUTDIR)/musl-linux64.tar \
+    $(NULL)
+
 default: $(OUTDIR)/cpython-linux64$(if $(PYBUILD_OPTIMIZED),-pgo,).tar
 
 $(OUTDIR)/image-%.tar: $(HERE)/%.Dockerfile $(COMMON_DEPENDS)
@@ -31,6 +36,9 @@ $(OUTDIR)/gcc-linux64.tar: $(OUTDIR)/binutils-linux64.tar $(HERE)/build-gcc.sh
 $(OUTDIR)/clang-linux64.tar: $(OUTDIR)/binutils-linux64.tar $(OUTDIR)/gcc-linux64.tar $(OUTDIR)/image-clang.tar $(HERE)/build-clang.sh
 	$(BUILD) clang
 
+$(OUTDIR)/musl-linux64.tar: $(BASE_TOOLCHAIN_DEPENDS) $(HERE)/build-musl.sh
+	$(BUILD) musl
+
 $(OUTDIR)/bdb-%.tar: $(OUTDIR)/image-build.tar $(TOOLCHAIN_DEPENDS) $(HERE)/build-bdb.sh
 	$(BUILD) --platform $* bdb
 

cpython-linux/build-musl.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+set -e
+
+cd /build
+
+tar -xf musl-${MUSL_VERSION}.tar.gz
+
+pushd musl-${MUSL_VERSION}
+
+./configure \
+    --prefix=/tools/host \
+    --disable-shared
+
+make -j `nproc`
+make -j `nproc` install DESTDIR=/build/out
+
+popd

cpython-linux/build.py

@@ -318,6 +318,24 @@ def build_clang(client, image):
                                tools_path)
 
 
+def build_musl(client, image):
+    musl_archive = download_entry('musl', BUILD)
+
+    with run_container(client, image) as container:
+        copy_file_to_container(musl_archive, container, '/build')
+        copy_file_to_container(SUPPORT / 'build-musl.sh', container, '/build')
+
+        env = {
+            'MUSL_VERSION': DOWNLOADS['musl']['version'],
+        }
+
+        container_exec(container, '/build/build-musl.sh',
+                       environment=env)
+
+        download_tools_archive(container, BUILD / 'musl-linux64.tar',
+                               'host')
+
+
 def build_libedit(client, image, platform):
     libedit_archive = download_entry('libedit', BUILD)
 
@@ -696,6 +714,9 @@ def main():
         elif action == 'gcc':
             build_gcc(client, get_image(client, 'gcc'))
 
+        elif action == 'musl':
+            build_musl(client, get_image(client, 'gcc'))
+
         elif action == 'libedit':
             build_libedit(client, get_image(client, 'build'), platform=args.platform)
 

pythonbuild/downloads.py

@@ -165,6 +165,12 @@
         'sha256': '7a62ac1a04408614fccdc506e4844b10cf0ad2c2b1677097f8f35d3a1344a950',
         'version': '3.1.6',
     },
+    'musl': {
+        'url': 'https://www.musl-libc.org/releases/musl-1.1.22.tar.gz',
+        'size': 987296,
+        'sha256': '8b0941a48d2f980fd7036cfbd24aa1d414f03d9a0652ecbd5ec5c7ff1bee29e3',
+        'version': '1.1.22',
+    },
     'ncurses': {
         'url': 'https://ftp.gnu.org/pub/gnu/ncurses/ncurses-6.1.tar.gz',
         'size': 3365395,