From 69eed07c025531e3463b8e99a5d3a9c07a0d9b37 Mon Sep 17 00:00:00 2001
From: John Sullivan <jsullivan@csumb.edu>
Date: Thu, 17 Sep 2020 14:14:59 -0700
Subject: [PATCH] zig: enable cross-compile support

---
 ...-to-use-llvm-config-to-find-cross-ta.patch | 39 ++++++++++++
 srcpkgs/zig/template                          | 60 ++++++++++++++++++-
 2 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 srcpkgs/zig/patches/0001-cmake-add-option-to-use-llvm-config-to-find-cross-ta.patch

diff --git a/srcpkgs/zig/patches/0001-cmake-add-option-to-use-llvm-config-to-find-cross-ta.patch b/srcpkgs/zig/patches/0001-cmake-add-option-to-use-llvm-config-to-find-cross-ta.patch
new file mode 100644
index 00000000000..04a4fbd4d19
--- /dev/null
+++ b/srcpkgs/zig/patches/0001-cmake-add-option-to-use-llvm-config-to-find-cross-ta.patch
@@ -0,0 +1,39 @@
+From 314c780371c3bfa3680445cec67f649800c6942b Mon Sep 17 00:00:00 2001
+From: John Sullivan <jsullivan@csumb.edu>
+Date: Sun, 20 Sep 2020 14:55:43 -0700
+Subject: [PATCH] cmake: add option to use llvm-config to find cross-target
+ llvm deps
+
+---
+ CMakeLists.txt       | 1 +
+ cmake/Findllvm.cmake | 2 +-
+ 2 files changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 27bc6a04f..ee323cce0 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -66,6 +66,7 @@ option(ZIG_FORCE_EXTERNAL_LLD "does nothing" OFF)
+ set(ZIG_TARGET_TRIPLE "native" CACHE STRING "arch-os-abi to output binaries for")
+ set(ZIG_TARGET_MCPU "baseline" CACHE STRING "-mcpu parameter to output binaries for")
+ set(ZIG_EXECUTABLE "" CACHE STRING "(when cross compiling) path to already-built zig binary")
++set(ZIG_PREFER_LLVM_CONFIG off CACHE BOOL "(when cross compiling) use llvm-config to find target llvm dependencies if needed")
+ 
+ find_package(llvm)
+ find_package(clang)
+diff --git a/cmake/Findllvm.cmake b/cmake/Findllvm.cmake
+index 7d6a4b04d..314367b7b 100644
+--- a/cmake/Findllvm.cmake
++++ b/cmake/Findllvm.cmake
+@@ -7,7 +7,7 @@
+ # LLVM_LIBRARIES
+ # LLVM_LIBDIRS
+ 
+-if("${ZIG_TARGET_TRIPLE}" STREQUAL "native")
++if(("${ZIG_TARGET_TRIPLE}" STREQUAL "native") OR ZIG_PREFER_LLVM_CONFIG)
+   find_program(LLVM_CONFIG_EXE
+       NAMES llvm-config-10 llvm-config-10.0 llvm-config100 llvm-config10 llvm-config
+       PATHS
+-- 
+2.28.0
+
diff --git a/srcpkgs/zig/template b/srcpkgs/zig/template
index c3ab8e62a11..f8343f9a27c 100644
--- a/srcpkgs/zig/template
+++ b/srcpkgs/zig/template
@@ -2,7 +2,8 @@
 pkgname=zig
 version=0.6.0
 revision=1
-archs="x86_64*"
+archs="x86_64* i686* aarch64* armv6l* armv7l*"
+wrksrc="${pkgname}-${version}"
 build_style=cmake
 makedepends="clang llvm10 lld-devel"
 short_desc="Programming language designed for robustness, optimality, and clarity"
@@ -11,9 +12,64 @@ license="MIT"
 homepage="https://ziglang.org/"
 distfiles="https://ziglang.org/download/${version}/zig-${version}.tar.xz"
 checksum=5d167dc19354282dd35dd17b38e99e1763713b9be8a4ba9e9e69284e059e7204
+patch_args="-Np1"
 nopie=yes
-nocross=yes
+
+# This is needed to prevent zig from dumping its global cache in /tmp
+export XDG_CACHE_HOME="${XBPS_BUILDDIR}/${wrksrc}/build/.cache"
+
+if [ "${CROSS_BUILD}" ]; then
+	# TODO _mcpu might be a candidate for cross-profiles
+	#
+	# Set _cross_triple and _mcpu for target triples that are not directly
+	# available in zig's targets.
+	#
+	# List targets and mcpu options with: zig targets
+
+	case "${XBPS_TARGET_MACHINE}" in
+		armv6l*)
+			_cross_triple="${XBPS_CROSS_TRIPLET}"
+			_mcpu="generic+v6k"
+			;;
+		armv7l*)
+			_cross_triple="${XBPS_CROSS_TRIPLET/armv7l/arm}"
+			_mcpu="generic+v7a"
+			;;
+		i686*)
+			_cross_triple="${XBPS_CROSS_TRIPLET/i686/i386}"
+			_mcpu="baseline"
+			;;
+		*)
+			_cross_triple="${XBPS_CROSS_TRIPLET}"
+			_mcpu="baseline"
+			;;
+	esac
+
+	hostmakedepends="zig llvm10"
+	configure_args+="
+	-DZIG_PREFER_LLVM_CONFIG=on
+	-DZIG_TARGET_TRIPLE=${_cross_triple}
+	-DZIG_TARGET_MCPU=${_mcpu}
+	-DZIG_EXECUTABLE='/usr/bin/zig'"
+fi
+
+pre_configure() {
+	local _llvm_config
+
+	# When cross-compiling, need to re-write the host root provided by llvm-config
+	# to the cross-target root
+	if [ "${CROSS_BUILD}" ]; then
+		_llvm_config="${XBPS_WRAPPERDIR}/llvm-config"
+
+		cat > "${_llvm_config}" <<-EOF
+		#!/bin/sh
+		/usr/bin/llvm-config "\$@" | sed 's,/usr,${XBPS_CROSS_BASE}/usr,g'
+		EOF
+		chmod +x "${_llvm_config}"
+	fi
+}
 
 post_install() {
+	# vmove zig for great justice
 	vlicense LICENSE
 }