Merge pull request #77 from NikVolf/do_not_export_mutable_globals

All globals, exported by env are non-mutable

src/interpreter/env.rs

@@ -86,7 +86,7 @@ pub struct EnvModuleInstance {
 impl EnvModuleInstance {
 	pub fn new(params: EnvParams, module: Module) -> Result<Self, Error> {
 		let mut instance = ModuleInstance::new(Weak::default(), "env".into(), module)?;
-		instance.instantiate(false, None)?;
+		instance.instantiate(None)?;
 
 		Ok(EnvModuleInstance {
 			_params: params,
@@ -183,19 +183,19 @@ pub fn env_module(params: EnvParams) -> Result<EnvModuleInstance, Error> {
 		// globals
 		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(DEFAULT_STACK_BASE as i32)])))
 			.with_export(ExportEntry::new("STACK_BASE".into(), Internal::Global(INDEX_GLOBAL_STACK_BASE)))
-		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, true), InitExpr::new(vec![Opcode::I32Const(DEFAULT_STACK_BASE as i32)])))
+		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(DEFAULT_STACK_BASE as i32)])))
 			.with_export(ExportEntry::new("STACKTOP".into(), Internal::Global(INDEX_GLOBAL_STACK_TOP)))
 		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const((DEFAULT_STACK_BASE + params.total_stack) as i32)])))
 			.with_export(ExportEntry::new("STACK_MAX".into(), Internal::Global(INDEX_GLOBAL_STACK_MAX)))
 		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const((DEFAULT_STACK_BASE + params.total_stack) as i32)])))
 			.with_export(ExportEntry::new("DYNAMIC_BASE".into(), Internal::Global(INDEX_GLOBAL_DYNAMIC_BASE)))
-		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, true), InitExpr::new(vec![Opcode::I32Const((DEFAULT_STACK_BASE + params.total_stack) as i32)])))
+		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const((DEFAULT_STACK_BASE + params.total_stack) as i32)])))
 			.with_export(ExportEntry::new("DYNAMICTOP_PTR".into(), Internal::Global(INDEX_GLOBAL_DYNAMICTOP_PTR)))
 		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, params.allow_memory_growth), InitExpr::new(vec![Opcode::I32Const(params.total_memory as i32)])))
 			.with_export(ExportEntry::new("TOTAL_MEMORY".into(), Internal::Global(INDEX_GLOBAL_TOTAL_MEMORY)))
-		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, true), InitExpr::new(vec![Opcode::I32Const(0)])))
+		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(0)])))
 			.with_export(ExportEntry::new("ABORT".into(), Internal::Global(INDEX_GLOBAL_ABORT)))
-		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, true), InitExpr::new(vec![Opcode::I32Const(0)])))
+		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(0)])))
 			.with_export(ExportEntry::new("EXITSTATUS".into(), Internal::Global(INDEX_GLOBAL_EXIT_STATUS)))
 		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(DEFAULT_TABLE_BASE as i32)]))) // TODO: what is this?
 			.with_export(ExportEntry::new("tableBase".into(), Internal::Global(INDEX_GLOBAL_TABLE_BASE)))

src/interpreter/module.rs

@@ -222,15 +222,13 @@ impl ModuleInstance {
 	}
 
 	/// Run instantiation-time procedures (validation). Module is not completely validated until this call.
-	pub fn instantiate<'a>(&mut self, is_user_module: bool, externals: Option<&'a HashMap<String, Arc<ModuleInstanceInterface + 'a>>>) -> Result<(), Error> {
+	pub fn instantiate<'a>(&mut self, externals: Option<&'a HashMap<String, Arc<ModuleInstanceInterface + 'a>>>) -> Result<(), Error> {
 		// validate start section
 		if let Some(start_function) = self.module.start_section() {
 			let func_type_index = self.require_function(ItemIndex::IndexSpace(start_function))?;
-			if is_user_module { // tests use non-empty main functions
+			let func_type = self.function_type_by_index(func_type_index)?;
-				let func_type = self.function_type_by_index(func_type_index)?;
+			if func_type.return_type() != None || func_type.params().len() != 0 {
-				if func_type.return_type() != None || func_type.params().len() != 0 {
+				return Err(Error::Validation("start function expected to have type [] -> []".into()));
-					return Err(Error::Validation("start function expected to have type [] -> []".into()));
-				}
 			}
 		}
 
@@ -244,7 +242,7 @@ impl ModuleInstance {
 					},
 					&Internal::Global(global_index) => {
 						self.global(ItemIndex::IndexSpace(global_index), None)
-							.and_then(|g| if g.is_mutable() && is_user_module {
+							.and_then(|g| if g.is_mutable() {
 								Err(Error::Validation(format!("trying to export mutable global {}", export.field())))
 							} else {
 								Ok(())
@@ -326,7 +324,7 @@ impl ModuleInstance {
 		}
 
 		// validate every function body in user modules
-		if is_user_module && function_section_len != 0 { // tests use invalid code
+		if function_section_len != 0 { // tests use invalid code
 			let function_section = self.module.function_section().expect("function_section_len != 0; qed");
 			let code_section = self.module.code_section().expect("function_section_len != 0; function_section_len == code_section_len; qed");
 			// check every function body

src/interpreter/program.rs

@@ -34,7 +34,7 @@ impl ProgramInstance {
 	/// Instantiate module with validation.
 	pub fn add_module<'a>(&self, name: &str, module: Module, externals: Option<&'a HashMap<String, Arc<ModuleInstanceInterface + 'a>>>) -> Result<Arc<ModuleInstance>, Error> {
 		let mut module_instance = ModuleInstance::new(Arc::downgrade(&self.essence), name.into(), module)?;
-		module_instance.instantiate(true, externals)?;
+		module_instance.instantiate(externals)?;
 
 		let module_instance = Arc::new(module_instance);
 		self.essence.modules.write().insert(name.into(), module_instance.clone());