argument parsing, mem ext stub

build/src/main.rs

@@ -81,11 +81,25 @@ fn main() {
 			.help("Injects RUNTIME_VERSION global export")
 			.takes_value(true)
 			.long("runtime-version"))
+		.arg(Arg::with_name("source_target")
+			.help("Skip symbol optimization step producing final wasm")
+			.takes_value(true)
+			.long("target"))
 		.get_matches();
 
     let target_dir = matches.value_of("target").expect("is required; qed");
     let wasm_binary = matches.value_of("wasm").expect("is required; qed");
-	let source_input = source::SourceInput::new(target_dir, wasm_binary);
+	let mut source_input = source::SourceInput::new(target_dir, wasm_binary);
+
+	let source_target_val = matches.value_of("source_target").unwrap_or_else(|| "wasm32-unknown-emscripten");
+	if source_target_val == "wasm32-unknown-unknown" {
+		source_input = source_input.unknown()
+	} else if source_target_val == "wasm32-unknown-emscripten" {
+		source_input = source_input.emscripten()
+	} else {
+		println!("--target can be: 'wasm32-unknown-emscripten' or 'wasm32-unknown-unknown'");
+		::std::process::exit(1);
+	}
 
 	process_output(&source_input).expect("Failed to process cargo target directory");
 

src/ext.rs

@@ -18,6 +18,28 @@ pub fn update_call_index(opcodes: &mut elements::Opcodes, original_imports: usiz
 	}
 }
 
+pub fn memory_section<'a>(module: &'a mut elements::Module) -> Option<&'a mut elements::MemorySection> {
+   for section in module.sections_mut() {
+		match section {
+			&mut elements::Section::Memory(ref mut sect) => {
+				return Some(sect);
+			},
+			_ => { }
+		}
+	}
+	None
+}
+
+pub fn externalize_mem(mut module: elements::Module) -> elements::Module {
+	let entry = memory_section(&mut module)
+		.expect("Memory section to exist")
+		.entries_mut()
+		.pop()
+		.expect("Own memory entry to exist in memory section");
+
+	module
+}
+
 pub fn externalize(
 	module: elements::Module,
 	replaced_funcs: Vec<&str>,