[glsl-new] put validation errors behind featureUsing glsl-validate feature (#127)

Cargo.toml

@@ -24,6 +24,7 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 default = []
 glsl_preprocessor = ["glsl"]
 glsl-new = ["pomelo"]
+glsl-validate = []
 glsl-out = []
 serialize = ["serde"]
 deserialize = ["serde"]

src/front/glsl_new/ast.rs

@@ -63,6 +63,7 @@ impl Context {
         None
     }
 
+    #[cfg(feature = "glsl-validate")]
     pub fn lookup_local_var_current_scope(&self, name: &str) -> Option<Handle<LocalVariable>> {
         if let Some(current) = self.scopes.last() {
             current.get(name).cloned()

src/front/glsl_new/error.rs

@@ -14,6 +14,7 @@ pub enum ErrorKind {
     ParserStackOverflow,
     NotImplemented(&'static str),
     UnknownVariable(TokenMetadata, String),
+    #[cfg(feature = "glsl-validate")]
     VariableAlreadyDeclared(String),
     ExpectedConstant,
     SemanticError(&'static str),
@@ -38,6 +39,7 @@ impl fmt::Display for ErrorKind {
             ErrorKind::UnknownVariable(meta, val) => {
                 write!(f, "Unknown variable {} at {:?}", val, meta)
             }
+            #[cfg(feature = "glsl-validate")]
             ErrorKind::VariableAlreadyDeclared(val) => {
                 write!(f, "Variable {} already decalred in current scope", val)
             }

src/front/glsl_new/parser.rs

@@ -545,6 +545,7 @@ pomelo! {
         // local variables
         for (id, initializer) in d.ids_initializers {
             // check if already declared in current scope
+            #[cfg(feature = "glsl-validate")]
             if extra.context.lookup_local_var_current_scope(&id).is_some() {
                 return Err(ErrorKind::VariableAlreadyDeclared(id))
             }