Misc testsuite feature gated (#113)

* Put misc_testsuite behind a feature gate

This PR puts building and generating of misc_testsuite behind
a feature gate "misc_testsuite". This is mainly to allow projects
which pull `wasi-common` as a dependency not to have to have
`wasm32-wasi` target installed in order to build it as it currently
is.

* Update the CI

* Rename feature to wasm_tests

* Explain integration testing in the README

.azure-pipelines.yml

@@ -58,7 +58,7 @@ jobs:
       displayName: Cargo build release
     - script: cargo build
       displayName: Cargo build
-    - bash: RUST_BACKTRACE=1 cargo test --all
+    - bash: RUST_BACKTRACE=1 cargo test --features wasm_tests --all
       displayName: Cargo test
     - script: cargo doc
       condition: eq(variables['Agent.OS'], 'Darwin')

Cargo.toml

@@ -10,6 +10,11 @@ edition = "2018"
 license = "Apache-2.0 WITH LLVM-exception"
 description = "WASI implementation in Rust"
 
+[features]
+# this feature requires wasm32-wasi target installed, and it enables wasm32
+# integration tests when run with `cargo test --features wasm_tests`
+wasm_tests = []
+
 [dependencies]
 wasi-common-cbindgen = { path = "wasi-common-cbindgen" }
 failure = "0.1"

README.md

@@ -39,6 +39,28 @@ In our Windows implementation, we currently support the minimal subset of [WASI
 which allows for running the very basic "Hello world!" style WASM apps. More coming shortly,
 so stay tuned!
 
+## Development hints
+When testing the crate, you may want to enable and run full wasm32 integration testsuite. This
+requires `wasm32-wasi` target installed which can be done as follows using [rustup]
+
+```
+rustup target add wasm32-wasi
+```
+
+[rustup]: https://rustup.rs
+
+Next initiate submodules containing the integration testsuite
+
+```
+git submodule update --init
+```
+
+Now, you should be able to run the integration testsuite by enabling the `wasm_tests` feature
+
+```
+cargo test --features wasm_tests
+```
+
 ## Third-Party Code
 Significant parts of our hostcall implementations are derived from the C implementations in
 `cloudabi-utils`. See [LICENSE.cloudabi-utils](LICENSE.cloudabi-utils) for license information.

build.rs

@@ -6,19 +6,25 @@
 //! Idea adapted from: https://github.com/CraneStation/wasmtime/blob/master/build.rs
 //! Thanks @sunfishcode
 
+fn main() {
+    #[cfg(feature = "wasm_tests")]
+    wasm_tests::build_and_generate_tests();
+}
+
+#[cfg(feature = "wasm_tests")]
+mod wasm_tests {
     use std::env;
     use std::fs::{read_dir, DirEntry, File};
     use std::io::{self, Write};
     use std::path::{Path, PathBuf};
     use std::process::{Command, Stdio};
 
-fn main() {
+    pub(crate) fn build_and_generate_tests() {
-    let out_dir =
+        let out_dir = PathBuf::from(
-        PathBuf::from(env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"));
+            env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"),
-    println!("OUT_DIR is {:?}", out_dir);
+        );
         let mut out = File::create(out_dir.join("misc_testsuite_tests.rs"))
             .expect("error generating test source file");
-
         build_tests("misc_testsuite", &out_dir).expect("building tests");
         test_directory(&mut out, "misc_testsuite", &out_dir).expect("generating tests");
     }
@@ -96,7 +102,11 @@ fn test_directory(out: &mut File, testsuite: &str, out_dir: &Path) -> io::Result
         Ok(())
     }
 
-fn write_testsuite_tests(out: &mut File, dir_entry: DirEntry, testsuite: &str) -> io::Result<()> {
+    fn write_testsuite_tests(
+        out: &mut File,
+        dir_entry: DirEntry,
+        testsuite: &str,
+    ) -> io::Result<()> {
         let path = dir_entry.path();
         let stemstr = path
             .file_stem()
@@ -206,3 +216,4 @@ fn no_preopens(testsuite: &str, name: &str) -> bool {
             unreachable!()
         }
     }
+}

tests/wasm_tests.rs

@@ -1,3 +1,5 @@
+#![cfg(feature = "wasm_tests")]
+
 mod runtime;
 mod utils;