func index in mapped error

src/interpreter/module.rs

@@ -312,9 +312,23 @@ impl ModuleInstanceInterface for ModuleInstance {
 				let function_body = code_section.bodies().get(index as usize).ok_or(Error::Validation(format!("Missing body for function {}", index)))?;
 				let mut locals = function_type.params().to_vec();
 				locals.extend(function_body.locals().iter().flat_map(|l| repeat(l.value_type()).take(l.count() as usize)));
-				let mut context = FunctionValidationContext::new(&self.module, &self.imports, &locals, DEFAULT_VALUE_STACK_LIMIT, DEFAULT_FRAME_STACK_LIMIT, &function_type);
+				let mut context = FunctionValidationContext::new(
+					&self.module, 
+					&self.imports, 
+					&locals, 
+					DEFAULT_VALUE_STACK_LIMIT, 
+					DEFAULT_FRAME_STACK_LIMIT, 
+					&function_type);
+
 				let block_type = function_type.return_type().map(BlockType::Value).unwrap_or(BlockType::NoResult);
-				Validator::validate_block(&mut context, false, block_type, function_body.code().elements(), Opcode::End)?;
+				Validator::validate_block(&mut context, false, block_type, function_body.code().elements(), Opcode::End)
+					.map_err(|e| { 
+						if let Error::Validation(msg) = e { 
+							Error::Validation(format!("Function #{} validation error: {}", index, msg))
+						} else {
+							e
+						}
+					})?;
 			}
 		}
 

src/interpreter/validator.rs

@@ -495,7 +495,14 @@ impl Validator {
 }
 
 impl<'a> FunctionValidationContext<'a> {
-	pub fn new(module: &'a Module, imports: &'a ModuleImports, locals: &'a [ValueType], value_stack_limit: usize, frame_stack_limit: usize, function: &FunctionType) -> Self {
+	pub fn new(
+		module: &'a Module, 
+		imports: &'a ModuleImports, 
+		locals: &'a [ValueType], 
+		value_stack_limit: usize, 
+		frame_stack_limit: usize, 
+		function: &FunctionType,
+	) -> Self {
 		FunctionValidationContext {
 			module: module,
 			imports: imports,