Index: devel/wasi-compiler-rt13/Makefile
===================================================================
--- /dev/null
+++ devel/wasi-compiler-rt13/Makefile
@@ -0,0 +1,49 @@
+PORTNAME=	compiler-rt
+DISTVERSION=	13.0.0
+CATEGORIES=	devel lang
+MASTER_SITES=	https://github.com/llvm/llvm-project/releases/download/llvmorg-${DISTVERSION:S/rc/-rc/}/ \
+		https://${PRE_}releases.llvm.org/${LLVM_RELEASE}/${RCDIR}
+PKGNAMEPREFIX=	wasi-
+PKGNAMESUFFIX=	${LLVM_SUFFIX}
+DISTNAME=	llvm-project-${DISTVERSION}.src
+DISTFILES=	llvm-project-${DISTVERSION}.src${EXTRACT_SUFX}
+
+MAINTAINER=	greg@unrelenting.technology
+COMMENT=	Clang builtins library for WebAssembly System Interface
+
+LICENSE=	LLVM2
+LICENSE_FILE=	${WRKSRC}/llvm/LICENSE.TXT
+LICENSE_NAME=	Apache License 2.0 with LLVM Exceptions
+LICENSE_PERMS=	dist-mirror dist-sell pkg-mirror pkg-sell auto-accept
+
+LLVM_RELEASE=	${DISTVERSION:C/rc.*//}
+LLVM_SUFFIX=	${LLVM_RELEASE:C/\.[0-9]\.[0-9]$//}
+LLVM_PREFIX=	${PREFIX}/llvm${LLVM_SUFFIX}
+
+WASI_SYSROOT=	${LOCALBASE}/share/wasi-sysroot
+
+BUILD_DEPENDS=	${WASI_SYSROOT}/include/stdarg.h:devel/wasi-libc \
+		clang${LLVM_SUFFIX}:devel/llvm${LLVM_SUFFIX}
+
+USES=		cmake tar:xz
+NO_ARCH=	yes
+
+PLIST_FILES=	llvm${LLVM_SUFFIX}/lib/clang/${LLVM_RELEASE}/lib/wasi/libclang_rt.builtins-wasm32.a
+
+CC=		${LOCALBASE}/bin/clang${LLVM_SUFFIX}
+CXX=		${LOCALBASE}/bin/clang++${LLVM_SUFFIX}
+
+CMAKE_SOURCE_PATH=	${WRKSRC}/compiler-rt/lib/builtins
+CMAKE_INSTALL_PREFIX=	${LLVM_PREFIX}/lib/clang/${LLVM_RELEASE}
+CMAKE_ARGS=	-DCMAKE_C_COMPILER_WORKS=1 \
+		-DCMAKE_SYSROOT=${WASI_SYSROOT} \
+		-DLLVM_CONFIG_PATH=${LOCALBASE}/bin/llvm-config${LLVM_SUFFIX} \
+		-DCOMPILER_RT_OS_DIR=wasi \
+		-DCOMPILER_RT_BAREMETAL_BUILD=TRUE \
+		-DCOMPILER_RT_DEFAULT_TARGET_TRIPLE=wasm32-wasi \
+		-DCOMPILER_RT_EXCLUDE_ATOMIC_BUILTIN=TRUE
+
+post-build:
+	${LOCALBASE}/bin/llvm-ranlib${LLVM_SUFFIX} ${CONFIGURE_WRKSRC}/lib/wasi/*.a
+
+.include <bsd.port.mk>
Index: devel/wasi-compiler-rt13/distinfo
===================================================================
--- /dev/null
+++ devel/wasi-compiler-rt13/distinfo
@@ -0,0 +1,3 @@
+TIMESTAMP = 1633602220
+SHA256 (llvm-project-13.0.0.src.tar.xz) = 6075ad30f1ac0e15f07c1bf062c1e1268c241d674f11bd32cdf0e040c71f2bf3
+SIZE (llvm-project-13.0.0.src.tar.xz) = 97577404
Index: devel/wasi-compiler-rt13/pkg-descr
===================================================================
--- /dev/null
+++ devel/wasi-compiler-rt13/pkg-descr
@@ -0,0 +1,7 @@
+The LLVM Project is a collection of modular and reusable compiler and
+toolchain technologies.
+
+This port includes Clang builtins for WASI
+(WebAssembly System Interface).
+
+WWW: http://llvm.org/