unix: install m4 and autoconf

A future commit will introduce patches to configure.ac, which means we
need to run autoconf. As macOS doesn't provide a sufficient autoconf
and we want to use the same version of autoconf everywhere, it makes
sense to build autoconf from source for all targets.

So this commit does that.

Autoconf requires m4, so we need to build and install m4 as well.

cpython-unix/Makefile

@@ -88,6 +88,15 @@ endif
 
 toolchain: $(TOOLCHAIN_TARGET)
 
+AUTOCONF_DEPENDS = \
+    $(PYTHON_DEP_DEPENDS) \
+    $(HERE)/build-autoconf.sh \
+    $(OUTDIR)/m4-$(M4_VERSION)-$(PACKAGE_SUFFIX).tar \
+    $(NULL)
+
+$(OUTDIR)/autoconf-$(AUTOCONF_VERSION)-$(PACKAGE_SUFFIX).tar: $(AUTOCONF_DEPENDS)
+	$(RUN_BUILD) --docker-image $(DOCKER_IMAGE_BUILD) autoconf
+
 $(OUTDIR)/bdb-$(BDB_VERSION)-$(PACKAGE_SUFFIX).tar: $(PYTHON_DEP_DEPENDS) $(HERE)/build-bdb.sh
 	$(RUN_BUILD) --docker-image $(DOCKER_IMAGE_BUILD) bdb
 
@@ -147,6 +156,9 @@ LIBXCB_DEPENDS = \
 $(OUTDIR)/libxcb-$(LIBXCB_VERSION)-$(PACKAGE_SUFFIX).tar: $(LIBXCB_DEPENDS)
 	$(RUN_BUILD) --docker-image $(DOCKER_IMAGE_XCB) libxcb
 
+$(OUTDIR)/m4-$(M4_VERSION)-$(PACKAGE_SUFFIX).tar: $(PYTHON_DEP_DEPENDS) $(HERE)/build-m4.sh
+	$(RUN_BUILD) --docker-image $(DOCKER_IMAGE_BUILD) m4
+
 $(OUTDIR)/ncurses-$(NCURSES_VERSION)-$(PACKAGE_SUFFIX).tar: $(PYTHON_DEP_DEPENDS) $(HERE)/build-ncurses.sh
 	$(RUN_BUILD) --docker-image $(DOCKER_IMAGE_BUILD) ncurses
 
@@ -229,11 +241,13 @@ PYTHON_DEPENDS := \
     $(PYTHON_SUPPORT_FILES) \
     $(OUTDIR)/versions/VERSION.pip \
     $(OUTDIR)/versions/VERSION.setuptools \
+    $(if $(NEED_AUTOCONF),$(OUTDIR)/autoconf-$(AUTOCONF_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_BDB),$(OUTDIR)/bdb-$(BDB_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_BZIP2),$(OUTDIR)/bzip2-$(BZIP2_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_GDBM),$(OUTDIR)/gdbm-$(GDBM_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_LIBEDIT),$(OUTDIR)/libedit-$(LIBEDIT_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_LIBFFI),$(OUTDIR)/libffi-$(LIBFFI_VERSION)-$(PACKAGE_SUFFIX).tar) \
+    $(if $(NEED_m4),$(OUTDIR)/m4-$(M4_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_NCURSES),$(OUTDIR)/ncurses-$(NCURSES_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_OPENSSL),$(OUTDIR)/openssl-$(OPENSSL_VERSION)-$(PACKAGE_SUFFIX).tar) \
     $(if $(NEED_PATCHELF),$(OUTDIR)/patchelf-$(PATCHELF_VERSION)-$(PACKAGE_SUFFIX).tar) \

cpython-unix/build-autoconf.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 -ex
+
+ROOT=`pwd`
+
+export PATH=${TOOLS_PATH}/${TOOLCHAIN}/bin:${TOOLS_PATH}/host/bin:$PATH
+
+tar -xf autoconf-${AUTOCONF_VERSION}.tar.gz
+
+pushd autoconf-${AUTOCONF_VERSION}
+
+CC="${HOST_CC}" CXX="${HOST_CXX}" CFLAGS="${EXTRA_HOST_CFLAGS} -fPIC" CPPFLAGS="${EXTRA_HOST_CFLAGS} -fPIC" LDFLAGS="${EXTRA_HOST_LDFLAGS}" ./configure \
+    --build=${BUILD_TRIPLE} \
+    --prefix=/tools/host
+
+make -j ${NUM_CPUS}
+make -j ${NUM_CPUS} install DESTDIR=${ROOT}/out

cpython-unix/build-cpython.sh

@@ -14,6 +14,26 @@ export PATH=${TOOLS_PATH}/${TOOLCHAIN}/bin:${TOOLS_PATH}/host/bin:${TOOLS_PATH}/
 # environment variable.
 export LLVM_PROFDATA=${TOOLS_PATH}/${TOOLCHAIN}/bin/llvm-profdata
 
+# autoconf has some paths hardcoded into scripts. These paths just work in
+# the containerized build environment. But from macOS the paths are wrong.
+# Explicitly point to the proper path via environment variable overrides.
+export AUTOCONF=${TOOLS_PATH}/host/bin/autoconf
+export AUTOHEADER=${TOOLS_PATH}/host/bin/autoheader
+export AUTOM4TE=${TOOLS_PATH}/host/bin/autom4te
+export autom4te_perllibdir=${TOOLS_PATH}/host/share/autoconf
+export AC_MACRODIR=${TOOLS_PATH}/host/share/autoconf
+export M4=${TOOLS_PATH}/host/bin/m4
+
+# The share/autoconf/autom4te.cfg file also hard-codes some paths. Rewrite
+# those to the real tools path.
+if [ "${PYBUILD_PLATFORM}" = "macos" ]; then
+  sed_args="-i '' -e"
+else
+  sed_args="-i"
+fi
+
+sed ${sed_args} "s|/tools/host|${TOOLS_PATH}/host|g" ${TOOLS_PATH}/host/share/autoconf/autom4te.cfg
+
 # We force linking of external static libraries by removing the shared
 # libraries. This is hacky. But we're building in a temporary container
 # and it gets the job done.

cpython-unix/build-m4.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 -ex
+
+ROOT=`pwd`
+
+export PATH=${TOOLS_PATH}/${TOOLCHAIN}/bin:${TOOLS_PATH}/host/bin:$PATH
+
+tar -xf m4-${M4_VERSION}.tar.xz
+
+pushd m4-${M4_VERSION}
+
+CC="${HOST_CC}" CXX="${HOST_CXX}" CFLAGS="${EXTRA_HOST_CFLAGS} -fPIC" CPPFLAGS="${EXTRA_HOST_CFLAGS} -fPIC" LDFLAGS="${EXTRA_HOST_LDFLAGS}" ./configure \
+    --build=${BUILD_TRIPLE} \
+    --prefix=/tools/host
+
+make -j ${NUM_CPUS}
+make -j ${NUM_CPUS} install DESTDIR=${ROOT}/out

cpython-unix/build.py

@@ -984,6 +984,20 @@ def main():
         elif action == "musl":
             build_musl(client, get_image(client, ROOT, BUILD, "gcc"), host_platform)
 
+        elif action == "autoconf":
+            simple_build(
+                settings,
+                client,
+                get_image(client, ROOT, BUILD, docker_image),
+                action,
+                host_platform=host_platform,
+                target_triple=target_triple,
+                optimizations=optimizations,
+                dest_archive=dest_archive,
+                tools_path="host",
+                extra_archives=["m4"],
+            )
+
         elif action == "libedit":
             build_libedit(
                 settings,
@@ -1014,6 +1028,7 @@ def main():
             "kbproto",
             "libffi",
             "libpthread-stubs",
+            "m4",
             "ncurses",
             "openssl",
             "patchelf",
@@ -1028,7 +1043,7 @@ def main():
             "xz",
             "zlib",
         ):
-            tools_path = "host" if action == "patchelf" else "deps"
+            tools_path = "host" if action in ("m4", "patchelf") else "deps"
 
             simple_build(
                 settings,