From 993521965db00c427b339d27d75b92964cf5ce69 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Capucho?= <jcapucho7@gmail.com>
Date: Sat, 6 Feb 2021 22:15:25 +0000
Subject: [PATCH] Add support for unary ops to glsl

---
 src/front/glsl/ast.rs    |  9 ++++++++-
 src/front/glsl/parser.rs | 28 ++++++++++++++++++++--------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/src/front/glsl/ast.rs b/src/front/glsl/ast.rs
index 157e72c0b9..4ece1ce9ed 100644
--- a/src/front/glsl/ast.rs
+++ b/src/front/glsl/ast.rs
@@ -3,7 +3,7 @@ use crate::{
     proc::{ResolveContext, Typifier},
     Arena, BinaryOperator, Binding, Constant, Expression, FastHashMap, Function, FunctionArgument,
     GlobalVariable, Handle, Interpolation, LocalVariable, Module, RelationalFunction, ShaderStage,
-    Statement, StorageClass, Type,
+    Statement, StorageClass, Type, UnaryOperator,
 };
 
 #[derive(Debug)]
@@ -57,6 +57,13 @@ impl Program {
         }))
     }
 
+    pub fn unary_expr(&mut self, op: UnaryOperator, tgt: &ExpressionRule) -> ExpressionRule {
+        ExpressionRule::from_expression(self.context.expressions.append(Expression::Unary {
+            op,
+            expr: tgt.expression,
+        }))
+    }
+
     /// Helper function to insert equality expressions, this handles the special
     /// case of `vec1 == vec2` and `vec1 != vec2` since in the IR they are
     /// represented as `all(equal(vec1, vec2))` and `any(notEqual(vec1, vec2))`
diff --git a/src/front/glsl/parser.rs b/src/front/glsl/parser.rs
index dc48cea8be..474a288323 100644
--- a/src/front/glsl/parser.rs
+++ b/src/front/glsl/parser.rs
@@ -8,7 +8,7 @@ pomelo! {
             Arena, BinaryOperator, Binding, Block, Constant,
             ConstantInner, EntryPoint, Expression,
             Function, GlobalVariable, Handle, Interpolation,
-            LocalVariable, ScalarValue,
+            LocalVariable, ScalarValue, ScalarKind,
             Statement, StorageAccess, StorageClass, StructMember,
             SwitchCase, Type, TypeInner, UnaryOperator, FunctionArgument
         };
@@ -319,15 +319,27 @@ pomelo! {
         //TODO
         return Err(ErrorKind::NotImplemented("--pre"))
     }
-    unary_expression ::= unary_operator unary_expression {
-        //TODO
-        return Err(ErrorKind::NotImplemented("unary_op"))
+    unary_expression ::= Plus unary_expression(tgt) {
+        tgt
+    }
+    unary_expression ::= Dash unary_expression(tgt) {
+        extra.unary_expr(UnaryOperator::Negate, &tgt)
+    }
+    unary_expression ::= Bang unary_expression(tgt) {
+        if let TypeInner::Scalar { kind: ScalarKind::Bool, .. } = extra.resolve_type(tgt.expression)? {
+            extra.unary_expr(UnaryOperator::Not, &tgt)
+        } else {
+            return Err(ErrorKind::SemanticError("Cannot apply '!' to non bool type".into()))
+        }
+    }
+    unary_expression ::= Tilde unary_expression(tgt) {
+        if extra.resolve_type(tgt.expression)?.scalar_kind() != Some(ScalarKind::Bool) {
+            extra.unary_expr(UnaryOperator::Not, &tgt)
+        } else {
+            return Err(ErrorKind::SemanticError("Cannot apply '~' to type".into()))
+        }
     }
 
-    unary_operator ::= Plus;
-    unary_operator ::= Dash;
-    unary_operator ::= Bang;
-    unary_operator ::= Tilde;
     multiplicative_expression ::= unary_expression;
     multiplicative_expression ::= multiplicative_expression(left) Star unary_expression(right) {
         extra.binary_expr(BinaryOperator::Multiply, &left, &right)