Define a fuzz target for the parser

cranelift/isle/Cargo.lock

@@ -35,6 +35,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "arbitrary"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "577b08a4acd7b99869f863c50011b01eb73424ccc798ecd996f2e24817adfca7"
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -148,6 +154,14 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "isle-fuzz"
+version = "0.0.0"
+dependencies = [
+ "isle",
+ "libfuzzer-sys",
+]
+
 [[package]]
 name = "islec"
 version = "0.1.0"
@@ -171,6 +185,17 @@ version = "0.2.101"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3cb00336871be5ed2c8ed44b60ae9959dc5b9f08539422ed43f09e34ecaeba21"
 
+[[package]]
+name = "libfuzzer-sys"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36a9a84a6e8b55dfefb04235e55edb2b9a2a18488fcae777a6bdaa6f06f1deb3"
+dependencies = [
+ "arbitrary",
+ "cc",
+ "once_cell",
+]
+
 [[package]]
 name = "log"
 version = "0.4.14"

cranelift/isle/Cargo.toml

@@ -1,2 +1,6 @@
 [workspace]
-members = [ "isle", "islec" ]
+members = [
+  "./fuzz",
+  "./isle",
+  "./islec",
+]

cranelift/isle/fuzz/.gitignore

@@ -0,0 +1,3 @@
+target
+corpus
+artifacts

cranelift/isle/fuzz/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "isle-fuzz"
+version = "0.0.0"
+authors = ["Automatically generated"]
+publish = false
+edition = "2018"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+isle = { path = "../isle" }
+libfuzzer-sys = "0.4"
+
+[[bin]]
+name = "parse"
+path = "fuzz_targets/parse.rs"
+test = false
+doc = false

cranelift/isle/fuzz/fuzz_targets/parse.rs

@@ -0,0 +1,9 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|s: &str| {
+    let lexer = isle::lexer::Lexer::from_str(s, "fuzz-input.isle");
+    let mut parser = isle::parser::Parser::new(lexer);
+    let _ = parser.parse_defs();
+});