Add a fuzz target for validating wasm-smith-generated modules

Author: fitzgen

fuzz/Cargo.toml

@@ -16,6 +16,7 @@ wasmparser = { path = "../crates/wasmparser" }
 wasmprinter = { path = "../crates/wasmprinter" }
 wast = { path = "../crates/wast" }
 wat = { path = "../crates/wat" }
+wasm-smith = "0.1.0"
 
 [[bin]]
 name = "text-lexer"
@@ -46,3 +47,9 @@ test = false
 name = "incremental-parse"
 path = "fuzz_targets/incremental-parse.rs"
 test = false
+
+[[bin]]
+name = "validate-valid-module"
+path = "fuzz_targets/validate-valid-module.rs"
+test = false
+doc = false

fuzz/fuzz_targets/validate-valid-module.rs

@@ -0,0 +1,23 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use wasm_smith::Module;
+
+// Define a fuzz target that accepts arbitrary
+// `Module`s as input.
+fuzz_target!(|m: Module| {
+    // Convert the module into Wasm bytes.
+    let bytes = m.to_bytes();
+
+    // Validate the module and assert that it passes
+    // validation.
+    let mut validator = wasmparser::Validator::new();
+    validator.wasm_features(wasmparser::WasmFeatures {
+        multi_value: true,
+        ..wasmparser::WasmFeatures::default()
+    });
+    if let Err(e) = validator.validate_all(&bytes) {
+        std::fs::write("test.wasm", bytes).unwrap();
+        panic!("Invalid module: {}", e);
+    }
+});