From 11e4cd6ba116efe54451de81a616dabd06c641a7 Mon Sep 17 00:00:00 2001
From: Sergey Pepyakin <s.pepyakin@gmail.com>
Date: Tue, 5 Dec 2017 12:57:42 +0100
Subject: [PATCH] Import section validation

---
 src/validation/mod.rs   | 27 +++++++++++++++++++++++++--
 src/validation/tests.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/validation/mod.rs b/src/validation/mod.rs
index c490417..af8ab91 100644
--- a/src/validation/mod.rs
+++ b/src/validation/mod.rs
@@ -99,6 +99,27 @@ pub fn validate_module(module: &Module) -> Result<ValidatedModule, Error> {
 		}
 	}
 
+	// validate import section
+	if let Some(import_section) = module.import_section() {
+		for import in import_section.entries() {
+			match import.external() {
+				&External::Function(function_type_index) => {
+					context.require_function(function_type_index)?;
+				},
+				&External::Global(ref global_type) => {
+					if global_type.is_mutable() {
+						return Err(Error(format!("trying to import mutable global {}", import.field())));
+					}
+				},
+				&External::Memory(ref memory_type) => {
+					memory_type.validate()?;
+				},
+				&External::Table(ref table_type) => {
+					table_type.validate()?;
+				},
+			}
+		}
+	}
 
 	// there must be no greater than 1 table in tables index space
 	if context.tables().len() > 1 {
@@ -110,6 +131,10 @@ pub fn validate_module(module: &Module) -> Result<ValidatedModule, Error> {
 		return Err(Error(format!("too many memory regions in index space: {}", context.memories().len())));
 	}
 
+
+	// TODO: data section
+	// TODO: element section
+
 	let ModuleContext {
 		types,
 		tables,
@@ -128,8 +153,6 @@ pub fn validate_module(module: &Module) -> Result<ValidatedModule, Error> {
 }
 
 fn prepare_context(module: &Module) -> Result<ModuleContext, Error> {
-	// TODO: Validate imports
-
 	// Copy types from module as is.
 	let types = module
 		.type_section()
diff --git a/src/validation/tests.rs b/src/validation/tests.rs
index 460d276..43f4f58 100644
--- a/src/validation/tests.rs
+++ b/src/validation/tests.rs
@@ -251,6 +251,33 @@ fn funcs() {
 	assert!(validate_module(&m).is_ok());
 }
 
+#[test]
+fn globals() {
+	// import immutable global is legal.
+	let m = module()
+		.with_import(
+			ImportEntry::new(
+				"env".into(),
+				"ext_global".into(),
+				External::Global(GlobalType::new(ValueType::I32, false))
+			)
+		)
+		.build();
+	assert!(validate_module(&m).is_ok());
+
+	// import mutable global is invalid.
+	let m = module()
+		.with_import(
+			ImportEntry::new(
+				"env".into(),
+				"ext_global".into(),
+				External::Global(GlobalType::new(ValueType::I32, true))
+			)
+		)
+		.build();
+	assert!(validate_module(&m).is_err());
+}
+
 // TODO: pepyakin
 // #[test]
 // fn if_else_with_return_type_validation() {