Make wasm-builder work with cargo install (#3043)

* Make `wasm-builder` work with `cargo install`

* Update `Cargo.lock`

substrate/Cargo.lock

@@ -4832,7 +4832,7 @@ dependencies = [
 
 [[package]]
 name = "substrate-wasm-builder"
-version = "1.0.3"
+version = "1.0.4"
 dependencies = [
  "build-helper 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "cargo_metadata 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",

substrate/core/utils/wasm-builder/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "substrate-wasm-builder"
-version = "1.0.3"
+version = "1.0.4"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Utility for building WASM binaries"
 edition = "2018"

substrate/core/utils/wasm-builder/src/wasm_project.rs

@@ -97,14 +97,26 @@ pub fn create_and_compile(cargo_manifest: &Path) -> (WasmBinary, WasmBinaryBloat
 ///
 /// If the `Cargo.lock` cannot be found, we emit a warning and return `None`.
 fn find_cargo_lock(cargo_manifest: &Path) -> Option<PathBuf> {
-	let mut path = build_helper::out_dir();
+	fn find_impl(mut path: PathBuf) -> Option<PathBuf> {
+		loop {
+			if path.join("Cargo.lock").exists() {
+				return Some(path.join("Cargo.lock"))
+			}
 
-	while path.pop() {
+			if !path.pop() {
-		if path.join("Cargo.lock").exists() {
+				return None;
-			return Some(path.join("Cargo.lock"))
+			}
 		}
 	}
 
+	if let Some(path) = find_impl(build_helper::out_dir()) {
+		return Some(path);
+	}
+
+	if let Some(path) = find_impl(cargo_manifest.to_path_buf()) {
+		return Some(path);
+	}
+
 	build_helper::warning!(
 		"Could not find `Cargo.lock` for `{}`, while searching from `{}`.",
 		cargo_manifest.display(),
@@ -136,12 +148,13 @@ fn get_wasm_binary_name(cargo_manifest: &Path) -> String {
 fn get_wasm_workspace_root() -> PathBuf {
 	let mut out_dir = build_helper::out_dir();
 
-	while out_dir.parent().is_some() {
+	loop {
-		if out_dir.parent().map(|p| p.ends_with("target")).unwrap_or(false) {
+		match out_dir.parent() {
-			return out_dir;
+			Some(parent) if out_dir.ends_with("build") => return parent.to_path_buf(),
+			_ => if !out_dir.pop() {
+				break;
+			}
 		}
-
-		out_dir.pop();
 	}
 
 	panic!("Could not find target dir in: {}", build_helper::out_dir().display())