Global validation

src/validation/mod.rs

@@ -4,7 +4,7 @@ mod module;
 mod func;
 
 use std::fmt;
-use elements::{Module, ResizableLimits, MemoryType, TableType, GlobalType, External};
+use elements::{Module, ResizableLimits, MemoryType, TableType, GlobalType, FunctionType, External, Opcode, ValueType};
 use common::stack;
 use self::module::ModuleContext;
 
@@ -23,26 +23,10 @@ impl From<stack::Error> for Error {
 }
 
 pub fn validate_module(module: &Module) -> Result<(), Error> {
-	if let Some(table_section) = module.table_section() {
+	prepare_context(module).map(|_| ())
-		table_section
-			.entries()
-			.iter()
-			.map(TableType::validate)
-			.collect::<Result<_, _>>()?
-	}
-
-	if let Some(mem_section) = module.memory_section() {
-		mem_section
-			.entries()
-			.iter()
-			.map(MemoryType::validate)
-			.collect::<Result<_, _>>()?
-	}
-
-	Ok(())
 }
 
-fn prepare_context(module: &Module) -> ModuleContext {
+fn prepare_context(module: &Module) -> Result<ModuleContext, Error> {
 	// Copy types from module as is.
 	let types = module
 		.type_section()
@@ -69,14 +53,69 @@ fn prepare_context(module: &Module) -> ModuleContext {
 	}
 
 	// Concatenate elements with defined in the module.
+	if let Some(table_section) = module.table_section() {
+		for table_entry in table_section.entries() {
+			table_entry.validate()?;
+			tables.push(table_entry.clone());
+		}
+	}
+	if let Some(mem_section) = module.memory_section() {
+		for mem_entry in mem_section.entries() {
+			mem_entry.validate()?;
+			memories.push(mem_entry.clone());
+		}
+	}
+	if let Some(global_section) = module.global_section() {
+		for global_entry in global_section.entries() {
+			let init = global_entry.init_expr().code();
+			if init.len() != 2 {
+				return Err(Error(format!("Init expression should always be with length 2")));
+			}
+			let init_expr_ty: ValueType = match init[0] {
+				Opcode::I32Const(_) => ValueType::I32,
+				Opcode::I64Const(_) => ValueType::I64,
+				Opcode::F32Const(_) => ValueType::F32,
+				Opcode::F64Const(_) => ValueType::F64,
+				Opcode::GetGlobal(idx) => {
+					match globals.get(idx as usize) {
+						Some(target_global) => {
+							if target_global.is_mutable() {
+								return Err(Error(
+									format!("Global {} is mutable", idx)
+								));
+							}
+							target_global.content_type()
+						},
+						None => return Err(Error(
+							format!("Global {} doesn't exists", idx)
+						)),
+					}
+				},
+				_ => return Err(Error(format!("Non constant opcode in init expr"))),
+			};
+			if init_expr_ty != global_entry.global_type().content_type() {
+				return Err(Error(
+					format!(
+						"Trying to initialize variable of type {:?} with value of type {:?}",
+						global_entry.global_type().content_type(),
+						init_expr_ty
+					)
+				));
+			}
+			if init[1] != Opcode::End {
+				return Err(Error(format!("Expression doesn't ends with `end` opcode")));
+			}
+			globals.push(global_entry.global_type().clone());
+		}
+	}
 
-	ModuleContext {
+	Ok(ModuleContext {
 		types,
 		tables,
 		memories,
 		globals,
 		func_type_indexes,
-	}
+	})
 }
 
 impl ResizableLimits {
@@ -140,7 +179,7 @@ mod tests {
 			.build();
 		assert!(validate_module(&m).is_ok());
 
-		// mem is always valid without max.
+		// mem is always valid without max
 		let m = module()
 			.memory()
 				.with_min(10)
@@ -169,7 +208,7 @@ mod tests {
 			.build();
 		assert!(validate_module(&m).is_ok());
 
-		// table is always valid without max.
+		// table is always valid without max
 		let m = module()
 			.table()
 				.with_min(10)
@@ -178,6 +217,115 @@ mod tests {
 		assert!(validate_module(&m).is_ok());
 	}
 
+	#[test]
+	fn global_init_const() {
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(
+							vec![Opcode::I32Const(42), Opcode::End]
+						)
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_ok());
+
+		// without delimiting End opcode
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::I32Const(42)])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+
+		// init expr type differs from declared global type
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I64, true),
+						InitExpr::new(vec![Opcode::I32Const(42), Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+	}
+
+	#[test]
+	fn global_init_global() {
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, false),
+						InitExpr::new(vec![Opcode::I32Const(0), Opcode::End])
+					)
+				)
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::GetGlobal(0), Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_ok());
+
+		// get_global can reference only previously defined globals
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::GetGlobal(0), Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+
+		// get_global can reference only const globals
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::I32Const(0), Opcode::End])
+					)
+				)
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::GetGlobal(0), Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+	}
+
+	#[test]
+	fn global_init_misc() {
+		// empty init expr
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+
+		// not an constant opcode used
+		let m = module()
+				.with_global(
+					GlobalEntry::new(
+						GlobalType::new(ValueType::I32, true),
+						InitExpr::new(vec![Opcode::Unreachable, Opcode::End])
+					)
+				)
+			.build();
+		assert!(validate_module(&m).is_err());
+	}
+
 	// #[test]
 	// fn if_else_with_return_type_validation() {
 	// 	let module_instance = ModuleInstance::new(Weak::default(), "test".into(), module().build()).unwrap();