Merge pull request #12 from arnaudgolfouse/stub-wasi-examples

Stub wasi examples

Author: astrale-sharp

Cargo.lock

@@ -39,19 +39,15 @@ The example can run using [`wasmi`](https://github.com/paritytech/wasmi).
 The command to run examples (from the top-level directory) is:
 
 ```sh
-cargo run -- <lang>
+cargo run [--features wasi] -- <lang>
 # or
-cargo run --no-default-features --features <abi> -- <lang>
-# or
-cargo run -- -i <PATH> <func> <args>
-# or
-cargo run --no-default-features --features <abi> -- -i <PATH> <func> <args>
+cargo run [--features wasi] -- -i <PATH> <func> <args>
 ```
 
 Where:
 
 - `<lang>` is `rust`, `zig` or `c`
-- `<abi>` is `abi_unknown` or `abi_wasi` (defaults to `abi_unknown`)
+- add `wasi` to the list of features to compile the example with WASI (required on the C example) and stub all the resulting WASI function if the runner is `host-wasmi`.
 - `<PATH>` is the path to a wasm file
 - `<func>` is the exported function to call in the wasm file, with `<args>` as arguments
 
@@ -65,16 +61,16 @@ Where:
 
 ```sh
 cargo run -- rust # compile and run the Rust example
+cargo run --features wasi -- rust # compile and run the Rust example with WASI (stubbed)
 cargo run -- zig # compile and run the Zig example
-# TODO irrelevant until next PR is merged
-# NOTE: this needs the abi_wasi feature, because the wasi functions are not stubbed. See the 'Tips' section to learn more.
-cargo run -- c # compile and run the C example
+# NOTE: this needs the wasi feature, as `emcc` only compiles in WASI.
+cargo run --features wasi -- c # compile and run the C example
 cargo run -- -i MY_WASM_FILE.wasm MY_FUNCTION arg1 arg2
 ```
 
 ### Tips
 
-- If the runner complains about missing definition for `wasi_snapshot_preview1` functions, try running your `.wasm` through [wasi-stub](./wasi-stub/). It stubs all wasi function in your wasm, so don't expect print or read_file to work anymore.
+- `host-wasmi` does not support running with WASI, and will stub all WASI functions instead.
 - host-wasmi compiles fastest 😉
 
 ## You need to stub a WebAssembly plugin

README.md

@@ -5,11 +5,11 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.71"
-host-wasmi = { path = "../host-wasmi" }
 cfg-if = "1.0.0"
+host-wasmi = { path = "../host-wasmi" }
+wasi-stub = { path = "../../wasi-stub", optional = true }
 
 
 [features]
-default = ["abi_unknown"]
-abi_unknown = []
-abi_wasi = []
+default = []
+wasi = ["dep:wasi-stub"]

examples/test-runner/Cargo.toml

@@ -6,15 +6,15 @@ use std::process::Command;
 
 use host_wasmi::PluginInstance;
 
-#[cfg(feature = "abi_unknown")]
+#[cfg(not(feature = "wasi"))]
 mod consts {
     pub const RUST_TARGET: &str = "wasm32-unknown-unknown";
     pub const RUST_PATH: &str =
         "examples/hello_rust/target/wasm32-unknown-unknown/debug/hello.wasm";
     pub const ZIG_TARGET: &str = "wasm32-freestanding";
 }
 
-#[cfg(feature = "abi_wasi")]
+#[cfg(feature = "wasi")]
 mod consts {
     pub const RUST_TARGET: &str = "wasm32-wasi";
     pub const RUST_PATH: &str = "examples/hello_rust/target/wasm32-wasi/debug/hello.wasm";
@@ -27,8 +27,9 @@ fn main() -> Result<()> {
     if args.is_empty() {
         anyhow::bail!("1 argument required: 'rust', 'zig' or 'c'")
     }
+    #[cfg(feature = "wasi")]
+    println!("[INFO] The WASI functions will be stubbed (by `wasi-stub`) for this run");
     let plugin_binary = match args[0].as_str() {
-        #[cfg(any(feature = "abi_unknown", feature = "abi_wasi"))]
         "rust" => {
             println!("=== compiling the Rust plugin");
             Command::new("cargo")
@@ -39,10 +40,9 @@ fn main() -> Result<()> {
                 .spawn()?
                 .wait()?;
             println!("===");
-            println!("getting wasm from: {}", consts::RUST_PATH);
+            println!("[INFO] getting wasm from: {}", consts::RUST_PATH);
             std::fs::read(consts::RUST_PATH)?
         }
-        #[cfg(any(feature = "abi_unknown", feature = "abi_wasi"))]
         "zig" => {
             println!("=== compiling the Zig plugin");
             Command::new("zig")
@@ -57,15 +57,13 @@ fn main() -> Result<()> {
                 .expect("do you have zig installed and in the path?")
                 .wait()?;
             println!("===");
-            println!("getting wasm from: examples/hello_zig/hello.wasm");
+            println!("[INFO] getting wasm from: examples/hello_zig/hello.wasm");
             std::fs::read("examples/hello_zig/hello.wasm")?
         }
         "c" => {
             println!("=== compiling the C plugin");
-            #[cfg(feature = "abi_unknown")]
-            println!("cfg(abi_unknown) has no effect for C example");
-            #[cfg(feature = "abi_wasi")]
-            println!("cfg(abi_wasi) has no effect for C example");
+            #[cfg(not(feature = "wasi"))]
+            eprintln!("WARNING: the C example should be compiled with `--features wasi`");
 
             println!("{}", std::env::current_dir().unwrap().display());
             Command::new("emcc")
@@ -80,22 +78,12 @@ fn main() -> Result<()> {
                 .expect("do you have emcc installed and in the path?")
                 .wait()?;
             println!("===");
-            println!("getting wasm from: examples/hello_c/hello.wasm");
+            println!("[INFO] getting wasm from: examples/hello_c/hello.wasm");
             std::fs::read("examples/hello_c/hello.wasm")?
         }
-
-        #[cfg(not(any(feature = "abi_unknown", feature = "abi_wasi")))]
-        "rust" | "zig" => {
-            panic!(
-                "for testing rust or zig, you must enable one feature in [abi_unknown, abi_wasi]"
-            )
-        }
         "-i" | "--input" => {
-            #[cfg(feature = "abi_wasi")]
-            println!("The feature abi_wasi is enabled but the file tested is provided by you.\nThis feature influence how the examples are built, they have no effect here.");
             custom_run = true;
-            println!("===");
-            println!("getting wasm from: {}", args[1].as_str());
+            println!("[INFO] getting wasm from: {}", args[1].as_str());
             println!(
                 "running func: {}",
                 args.get(2)
@@ -107,19 +95,33 @@ fn main() -> Result<()> {
         _ => anyhow::bail!("unknown argument '{}'", args[0].as_str()),
     };
 
+    #[cfg(feature = "wasi")]
+    let plugin_binary = {
+        println!("[INFO] Using wasi-stub");
+        let res = wasi_stub::stub_wasi_functions(&plugin_binary)?;
+        println!("[INFO] WASI functions have been stubbed");
+        res
+    };
+
     let mut plugin_instance = PluginInstance::new_from_bytes(plugin_binary).unwrap();
     if custom_run {
-        println!(
-            "{:?}",
-            plugin_instance.call(
-                args[2].as_str(),
-                args.iter()
-                    .skip(3)
-                    .map(|x| x.as_bytes())
-                    .collect::<Vec<_>>()
-                    .as_slice()
-            )
-        );
+        let function = args[2].as_str();
+        let args = args
+            .iter()
+            .skip(3)
+            .map(|x| x.as_bytes())
+            .collect::<Vec<_>>();
+        let result = match plugin_instance.call(function, &args) {
+            Ok(res) => res,
+            Err(err) => {
+                eprintln!("Error: {err}");
+                return Ok(());
+            }
+        };
+        match String::from_utf8(result) {
+            Ok(s) => println!("{s}"),
+            Err(_) => panic!("Error: function call '{function}' did not return UTF-8"),
+        }
         return Ok(());
     }
 
@@ -135,7 +137,7 @@ fn main() -> Result<()> {
         let result = match plugin_instance.call(function, args) {
             Ok(res) => res,
             Err(err) => {
-                println!("Error: {err}");
+                eprintln!("Error: {err}");
                 continue;
             }
         };

examples/test-runner/src/main.rs

@@ -5,5 +5,6 @@ version = "0.1.0"
 authors = ["Arnaud Golfouse <[email protected]>"]
 
 [dependencies]
-wasm-encoder = "0.29.0"
-wasmparser = "0.107.0"
+wasm-encoder = "0.31.0"
+wasmparser = "0.109.0"
+thiserror = "1.0"