From a419f01538607677b2bb599dda0c35a437316b3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Marie?= <semarie@online.fr>
Date: Mon, 8 Nov 2021 18:54:45 +0000
Subject: [PATCH] initial import

---
 README.md        | 63 ++++++++++++++++++++++++++++++++++++++
 build-ziglibc.sh | 79 ++++++++++++++++++++++++++++++++++++++++++++++++
 tests/hello.c    |  9 ++++++
 tests/hello.zig  |  5 +++
 4 files changed, 156 insertions(+)
 create mode 100644 README.md
 create mode 100755 build-ziglibc.sh
 create mode 100644 tests/hello.c
 create mode 100644 tests/hello.zig

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2b03227
--- /dev/null
+++ b/README.md
@@ -0,0 +1,63 @@
+OpenBSD ZIG_LIBC support
+========================
+
+Simple shell script to build a `ZIG_LIBC` environment for [Zig](https://ziglang.org/) targeting [OpenBSD](https://www.openbsd.org/).
+
+Usage
+-----
+
+```
+$ ./build-ziglibc.sh
+usage: ./build-ziglibc.sh url output-dir
+```
+
+- *url* : URL pointing to OpenBSD sets.
+
+  Typical url to use: https://cdn.openbsd.org/pub/OpenBSD/*version*/*platform*/
+
+  Please note that OpenBSD officially support only the two last
+  released versions. Snapshots url is also valid for targeting
+  -current, but be aware that it is a moving target.
+
+  Refer to [supported platforms](https://www.openbsd.org/plat.html)
+  list from OpenBSD site web for the name used.
+
+- *output-dir* : where to put the environment.
+
+  Prefer absolute path: it will be used in generated `libc.conf` file.
+
+  The directory will be created.
+
+
+Examples of url
+---------------
+
+- OpenBSD 6.9 [amd64](https://www.openbsd.org/amd64.html) (x86_64 on Linux world)
+
+  https://cdn.openbsd.org/pub/OpenBSD/6.9/amd64/
+
+- OpenBSD -current [i386](https://www.openbsd.org/i386.html)
+
+  https://cdn.openbsd.org/pub/OpenBSD/snapshots/i386/
+
+
+Use the environment
+-------------------
+
+```
+$ ZIG_LIBC=path/to/amd64/libc.conf zig build-exe -target x86_64-openbsd -o test/helloz test/hello.zig
+$ ZIG_LIBC=path/to/amd64/libc.conf zig cc -target x86_64-openbsd -o test/helloc test/hello.c
+```
+
+Make shell wrapper
+------------------
+
+For easy use of crosscompilation, you could create a shell wrapper
+named `x86_64-openbsd-cc`:
+
+```
+#!/bin/sh
+exec env ZIG_LIBC=path/to/amd64/libc.conf zig cc -target x86_64-openbsd "$@"
+```
+
+And do the same for `x86_64-openbsd-c++`, `x86_64-openbsd-ar`, …
diff --git a/build-ziglibc.sh b/build-ziglibc.sh
new file mode 100755
index 0000000..57283bd
--- /dev/null
+++ b/build-ziglibc.sh
@@ -0,0 +1,79 @@
+#!/bin/sh
+set -eu
+
+# tool used to download. url as argument, output to stdout.
+DOWNLOAD_BIN=${DOWNLOAD_BIN:-ftp -Vo-}
+#DOWNLOAD_BIN=${DOWNLOAD_BIN:-curl -s}
+
+if [ $# -ne 2 ]; then
+    cat >&2 <<EOF
+usage: ${0} url output-dir
+
+  examples:
+    - ${0} https://cdn.openbsd.org/pub/OpenBSD/6.9/amd64/ \${PWD}/6.9/amd64
+    - ${0} https://cdn.openbsd.org/pub/OpenBSD/snapshots/i386/ \${PWD}/snapshots/i386
+
+EOF
+    exit 1
+fi
+
+url="${1}"
+target_directory="${2}"
+
+if [ -r "${target_directory}/libc.conf" ] ; then
+    echo "warn: ${target_directory}/libc.conf already exists" >&2
+    exit 0
+fi
+
+echo "- Getting OpenBSD version" >&2
+target_version=`${DOWNLOAD_BIN} "${url}/SHA256" \
+    | sed -ne 's,.*(base\([0-9]\)\([0-9]\)\.tgz).*,\1\2,p'`
+
+echo "- Downloading and extracting libc environment" >&2
+mkdir -p "${target_directory}"
+cat >"${target_directory}/CACHEDIR.TAG" <<EOF
+Signature: 8a477f597d28d172789f06886806bc55
+# This file is a cache directory tag created by ${0}.
+# For information about cache directory tags see https://bford.info/cachedir/
+EOF
+
+${DOWNLOAD_BIN} "${url}/base${target_version}.tgz" \
+    | tar zxf - -C "${target_directory}" ./usr/include ./usr/lib
+${DOWNLOAD_BIN} "${url}/comp${target_version}.tgz" \
+    | tar zxf - -C "${target_directory}" ./usr/include ./usr/lib
+
+echo "- Creating linux-like library links" >&2
+for lib in "${target_directory}"/usr/lib/lib*.so.*.* ; do
+    ln -fs -- "${lib}" "${lib%.*.*}"
+done
+
+echo "- Creating ZIG_LIBC file" >&2
+cat >"${target_directory}/libc.conf" <<EOF
+# The directory that contains \`stdlib.h\`.
+# On POSIX-like systems, include directories be found with: \`cc -E -Wp,-v -xc /dev/null\`
+include_dir=${target_directory}/usr/include
+
+# The system-specific include directory. May be the same as \`include_dir\`.
+# On Windows it's the directory that includes \`vcruntime.h\`.
+# On POSIX it's the directory that includes \`sys/errno.h\`.
+sys_include_dir=${target_directory}/usr/include
+
+# The directory that contains \`crt1.o\` or \`crt2.o\`.
+# On POSIX, can be found with \`cc -print-file-name=crt1.o\`.
+# Not needed when targeting MacOS.
+crt_dir=${target_directory}/usr/lib
+
+# The directory that contains \`vcruntime.lib\`.
+# Only needed when targeting MSVC on Windows.
+msvc_lib_dir=
+
+# The directory that contains \`kernel32.lib\`.
+# Only needed when targeting MSVC on Windows.
+kernel32_lib_dir=
+
+# The directory that contains \`crtbeginS.o\` and \`crtendS.o\`
+# Only needed when targeting Haiku.
+gcc_dir=
+EOF
+
+echo "ZIG_LIBC=${target_directory}/libc.conf"
diff --git a/tests/hello.c b/tests/hello.c
new file mode 100644
index 0000000..876ec41
--- /dev/null
+++ b/tests/hello.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+main(int argc, char *argv[])
+{
+	printf("Hello world\n");
+	return EXIT_SUCCESS;
+}
diff --git a/tests/hello.zig b/tests/hello.zig
new file mode 100644
index 0000000..7a8e7be
--- /dev/null
+++ b/tests/hello.zig
@@ -0,0 +1,5 @@
+const std = @import("std");
+
+pub fn main() void {
+    std.debug.print("Hello world\n", .{});
+}