From 13f07e2b98f62af575219142acacdebf9dbc103c Mon Sep 17 00:00:00 2001
From: Greyson Christoforo <grey@christoforo.net>
Date: Tue, 5 Jan 2021 09:54:10 +0000
Subject: [PATCH] add wasm32-unknown-unknown target for the rust compiler

---
 rust/trunk/PKGBUILD | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/rust/trunk/PKGBUILD b/rust/trunk/PKGBUILD
index 394a51bbf68e..15277e0fe310 100644
--- a/rust/trunk/PKGBUILD
+++ b/rust/trunk/PKGBUILD
@@ -4,7 +4,7 @@
 # Contributor: Daniel Micay <danielmicay@gmail.com>
 # Contributor: userwithuid <userwithuid@gmail.com>
 
-pkgname=('rust' 'lib32-rust-libs' 'rust-musl' 'rust-docs')
+pkgname=('rust' 'lib32-rust-libs' 'rust-musl' 'rust-docs' 'rust-wasm')
 epoch=1
 pkgver=1.49.0
 pkgrel=1
@@ -36,12 +36,16 @@ validpgpkeys=('108F66205EAEB0AAA8DD5E1C85AB96E6FA1BE5FE'  # Rust Language (Tag a
 prepare() {
   cd "rustc-$pkgver-src"
 
+  # use wasm-ld instead of rust-ldd for wasm linker
+  # https://bugs.gentoo.org/715348
+  sed '/linker:/ s/rust-lld/wasm-ld/' -i compiler/rustc_target/src/spec/wasm32_base.rs
+
   cat >config.toml <<END
 [llvm]
 link-shared = true
 
 [build]
-target = ["x86_64-unknown-linux-gnu", "i686-unknown-linux-gnu", "x86_64-unknown-linux-musl"]
+target = ["x86_64-unknown-linux-gnu", "i686-unknown-linux-gnu", "x86_64-unknown-linux-musl", "wasm32-unknown-unknown"]
 tools = ["cargo", "rls", "clippy", "miri", "rustfmt", "analysis", "src"]
 cargo = "/usr/bin/cargo"
 rustc = "/usr/bin/rustc"
@@ -67,11 +71,19 @@ channel = "stable"
 
 rpath = false
 
+# https://github.com/rust-lang/rust/issues/74976#issuecomment-689665932
+deny-warnings = false
+
 [target.x86_64-unknown-linux-gnu]
 llvm-config = "/usr/bin/llvm-config"
 
 [target.x86_64-unknown-linux-musl]
 musl-root = "/usr/lib/musl"
+
+[target.wasm32-unknown-unknown]
+wasi-root = "/usr/lib/wasi"
+profiler = false
+
 END
 }
 
@@ -99,6 +111,7 @@ build() {
   # move docs and cross targets out of the way for splitting
   mv dest-rust/usr/lib/rustlib/i686-unknown-linux-gnu dest-i686
   mv dest-rust/usr/lib/rustlib/x86_64-unknown-linux-musl dest-musl
+  mv dest-rust/usr/lib/rustlib/wasm32-unknown-unknown dest-wasm
   mv dest-rust/usr/share/doc dest-doc
 }
 
@@ -142,6 +155,17 @@ package_lib32-rust-libs() {
   ln -srft "$pkgdir"/usr/lib32 "$pkgdir"/usr/lib/rustlib/i686-unknown-linux-gnu/lib/*.so
 }
 
+package_rust-wasm() {
+  pkgdesc='Wasm target for Rust'
+  depends=('lld')  # brings /usr/bin/wasm-ld
+
+  cd "rustc-$pkgver-src"
+  install -Dm644 -t "$pkgdir/usr/share/licenses/$pkgname" LICENSE*
+
+  install -d "$pkgdir"/usr/lib/rustlib/
+  cp -a dest-wasm "$pkgdir"/usr/lib/rustlib/wasm32-unknown-unknown
+}
+
 package_rust-musl() {
   pkgdesc='Musl target for Rust'