Add the Occlum-compatible Rust toolchains and a demo

demos/README.md

@@ -19,6 +19,7 @@ This set of demos shows how real-world apps can be easily run inside SGX enclave
 * [grpc](grpc/): A client and server communicating through [gRPC](https://grpc.io/).
 * [openvino](openvino/) A benchmark of [OpenVINO Inference Engine](https://docs.openvinotoolkit.org/2019_R3/_docs_IE_DG_inference_engine_intro.html).
 * [python](python/) A demo of [Python](https://www.python.org).
+* [rust](rust/) A demo of [Rust](https://www.rust-lang.org/).
 * [sqlite](sqlite/) A demo of [SQLite](https://www.sqlite.org) SQL database engine.
 * [tensorflow_lite](tensorflow_lite/): A demo and benchmark of [Tensorflow Lite](https://www.tensorflow.org/lite) inference engine.
 * [xgboost](xgboost/): A demo of [XGBoost](https://xgboost.readthedocs.io/en/latest/).

demos/rust/README.md

@@ -0,0 +1,27 @@
+# Use Rust with Occlum
+
+This directory contains scripts and source code to demonstrate how to
+compile and run Rust programs on Occlum.
+
+## occlum-cargo and occlum-rustc
+
+We introduce cargo and rustc wrappers called occlum-cargo and occlum-rustc
+respectively. They wrap the original commands with options specific to occlum.
+Refer to tools/toolchains/rust/build.sh for more information.
+
+## rust\_app
+
+This directory contains source code of a Rust program with a cpp FFI. The cpp
+interface increments the input by one. Rust code calls the function and
+displays the result on the terminal.
+
+One can use occlum-cargo in the way cargo is used. In the rust\_app directory,
+calling ```occlum-cargo build``` will build the demo and ```occlum-cargo run```
+will run the demo on host. To run the demo in occlum, run:
+```
+run_rust_demo_on_occlum.sh
+```
+The output will be displayed on the terminal:
+```
+5 + 1 = 6
+```

demos/rust/run_rust_demo_on_occlum.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+
+# compile rust_app
+pushd rust_app
+occlum-cargo build
+popd
+
+# initialize occlum workspace
+rm -rf occlum_context && mkdir occlum_context && cd occlum_context
+
+occlum init
+cp ../rust_app/target/x86_64-unknown-linux-musl/debug/rust_app image/bin
+
+occlum build
+occlum run /bin/rust_app

demos/rust/rust_app/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "rust_app"
+version = "1.0.0"
+authors = ["He Sun <bochang.sh@antfin.com>"]
+build = "build.rs"
+
+[dependencies]
+libc = "0.2"
+
+[build-dependencies]
+cc = "1.0"

demos/rust/rust_app/build.rs

@@ -0,0 +1,8 @@
+extern crate cc;
+
+fn main() {
+    cc::Build::new()
+        .file("src/util.cpp")
+        .cpp(true)
+        .compile("libutil.a");
+}

demos/rust/rust_app/src/main.rs

@@ -0,0 +1,12 @@
+extern crate libc;
+
+extern "C" {
+    fn increment_by_one(input: *mut libc::c_int);
+}
+
+fn main() {
+    let mut input = 5;
+    let old = input;
+    unsafe { increment_by_one(&mut input) };
+    println!("{} + 1 = {}", old, input);
+}

demos/rust/rust_app/src/util.cpp

@@ -0,0 +1,4 @@
+extern "C"
+void increment_by_one(int *input) {
+    *input += 1;
+}

tools/docker/Dockerfile.centos7.5

@@ -100,6 +100,12 @@ WORKDIR /tmp
 RUN ./build.sh
 ENV PATH="/usr/local/occlum/golang/bin:$PATH"
 
+# Install Occlum Rust toolchain
+COPY toolchains/rust/* /tmp/
+WORKDIR /tmp
+RUN ./build.sh
+ENV PATH="/opt/occlum/toolchains/rust/bin:$PATH"
+
 # Install the latest version of Occlum
 WORKDIR /root
 RUN git clone https://github.com/occlum/occlum && \

tools/docker/Dockerfile.ubuntu18.04

@@ -86,6 +86,12 @@ WORKDIR /tmp
 RUN ./build.sh
 ENV PATH="/usr/local/occlum/golang/bin:$PATH"
 
+# Install Occlum Rust toolchain
+COPY toolchains/rust/* /tmp/
+WORKDIR /tmp
+RUN ./build.sh
+ENV PATH="/opt/occlum/toolchains/rust/bin:$PATH"
+
 # Install the latest version of Occlum
 WORKDIR /root
 RUN git clone https://github.com/occlum/occlum && \

tools/toolchains/rust/build.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+THIS_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}"  )" >/dev/null 2>&1 && pwd )"
+INSTALL_DIR=/opt/occlum/toolchains/rust
+
+mkdir -p ${INSTALL_DIR}/bin
+
+rustup target add x86_64-unknown-linux-musl
+
+# Generate the wrapper for Cargo
+# Use -crt-static to dynamically link the application to musl libc library.
+# Refer to https://github.com/rust-lang/rfcs/blob/master/text/1721-crt-static.md
+# for more information about crt-static
+cat > ${INSTALL_DIR}/bin/occlum-cargo <<EOF
+#!/bin/bash
+env CC_x86_64_unknown_linux_musl=x86_64-linux-musl-gcc \
+CCFLAGS_x86_64_unknown_linux_musl="-fPIC -pie -Wl,-rpath,/opt/occlum/toolchains/gcc/x86_64-linux-musl/lib" \
+CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++ \
+CXXFLAGS_x86_64_unknown_linux_musl="-fPIC -pie -Wl,-rpath,/opt/occlum/toolchains/gcc/x86_64-linux-musl/lib" \
+RUSTFLAGS="-C target-feature=-crt-static -C linker=occlum-gcc" \
+CARGO_BUILD_TARGET=x86_64-unknown-linux-musl \
+cargo "\$@"
+EOF
+
+# Generate the wrapper for rustc
+cat > ${INSTALL_DIR}/bin/occlum-rustc <<EOF
+#!/bin/bash
+rustc -C linker=occlum-gcc -C target-feature=-crt-static "\$@" --target=x86_64-unknown-linux-musl
+EOF
+
+chmod +x ${INSTALL_DIR}/bin/occlum-cargo
+chmod +x ${INSTALL_DIR}/bin/occlum-rustc