Add check_contract utility

packages/vm/Cargo.toml

@@ -29,6 +29,10 @@ cranelift = ["wasmer/cranelift"]
 # See https://bheisler.github.io/criterion.rs/book/faq.html#cargo-bench-gives-unrecognized-option-errors-for-valid-command-line-options
 bench = false
 
+[[example]]
+name = "check_contract"
+required-features = ["iterator"]
+
 [dependencies]
 clru = "0.4.0"
 # Uses the path when built locally; uses the given version from crates.io when published

packages/vm/examples/check_contract.rs

@@ -0,0 +1,36 @@
+use std::fs::File;
+use std::io::Read;
+
+use clap::{App, Arg};
+
+use cosmwasm_vm::features_from_csv;
+use cosmwasm_vm::internals::{check_wasm, compile};
+
+pub fn main() {
+    let matches = App::new("Contract checking")
+        .version("0.1.0")
+        .long_about("Checks the given wasm file (memories, exports, imports, supported features, and non-determinism).")
+        .author("Mauro Lacy <[email protected]>")
+        .arg(
+            Arg::with_name("WASM")
+                .help("Wasm file to read and compile")
+                .required(true)
+                .index(1),
+        )
+        .get_matches();
+
+    // File
+    let path = matches.value_of("WASM").expect("Error parsing file name");
+    let mut file = File::open(path).unwrap();
+
+    // Read wasm
+    let mut wasm = Vec::<u8>::new();
+    file.read_to_end(&mut wasm).unwrap();
+
+    // Check wasm
+    check_wasm(&wasm, &features_from_csv("staking")).unwrap();
+
+    // Compile module
+    compile(&wasm, None).unwrap();
+    println!("contract checks passed.")
+}

packages/vm/src/lib.rs

@@ -57,5 +57,6 @@ pub mod internals {
     //! Please don't use any of these types directly, as
     //! they might change frequently or be removed in the future.
 
+    pub use crate::compatibility::check_wasm;
     pub use crate::wasm_backend::{compile, make_runtime_store};
 }