Move parenthesizing expressions to Formatter

[libs/gl.git] / source / glsl / output.cpp

diff --git a/source/glsl/output.cpp b/source/glsl/output.cpp
index 35c52fec51fc109ada7ad10f7e73b48836955cd2..f1e9b4be99ca8a2582e7a97944c0c16666f80540 100644 (file)
--- a/source/glsl/output.cpp
+++ b/source/glsl/output.cpp
@@ -108,6 +108,38 @@ void Formatter::visit(Block &block)
                append(format("\n%s}", string(brace_indent*2, ' ')));
 }
 
+void Formatter::visit_expression(Expression &expr, const Operator *outer_oper, bool on_rhs)
+{
+       unsigned outer_precedence = (outer_oper ? outer_oper->precedence : 20);
+       unsigned inner_precedence = (expr.oper ? expr.oper->precedence : 0);
+
+       bool needs_parentheses = (inner_precedence>=outer_precedence);
+
+       // Omit parentheses if the outer operator encloses this operand.
+       if(outer_oper && outer_oper->type==Operator::BINARY && outer_oper->token2[0] && on_rhs)
+               needs_parentheses = false;
+
+       if(expr.oper)
+       {
+               /* Omit parentheses if the inner expression's operator sits between the
+               expression and the outer operator. */
+               bool oper_on_left = expr.oper->type==Operator::PREFIX;
+               bool oper_on_right = expr.oper->type==Operator::POSTFIX || (expr.oper->type==Operator::BINARY && expr.oper->token2[0]);
+               if(expr.oper && ((oper_on_left && on_rhs) || (oper_on_right && !on_rhs)))
+                       needs_parentheses = false;
+
+               // Omit parentheses if the operator's natural grouping works out.
+               if(expr.oper==outer_oper)
+                       needs_parentheses = (expr.oper->assoc!=Operator::ASSOCIATIVE && on_rhs!=(expr.oper->assoc==Operator::RIGHT_TO_LEFT));
+       }
+
+       if(needs_parentheses)
+               append('(');
+       expr.visit(*this);
+       if(needs_parentheses)
+               append(')');
+}
+
 void Formatter::visit(Literal &literal)
 {
        append(literal.token);
@@ -132,13 +164,13 @@ void Formatter::visit(InterfaceBlockReference &iface)
 
 void Formatter::visit(MemberAccess &memacc)
 {
-       memacc.left->visit(*this);
+       visit_expression(*memacc.left, memacc.oper, false);
        append(format(".%s", memacc.member));
 }
 
 void Formatter::visit(Swizzle &swizzle)
 {
-       swizzle.left->visit(*this);
+       visit_expression(*swizzle.left, swizzle.oper, false);
        append(format(".%s", swizzle.component_group));
 }
 
@@ -146,35 +178,35 @@ void Formatter::visit(UnaryExpression &unary)
 {
        if(unary.oper->type==Operator::PREFIX)
                append(unary.oper->token);
-       unary.expression->visit(*this);
+       visit_expression(*unary.expression, unary.oper, unary.oper->type==Operator::PREFIX);
        if(unary.oper->type==Operator::POSTFIX)
                append(unary.oper->token);
 }
 
 void Formatter::visit(BinaryExpression &binary)
 {
-       binary.left->visit(*this);
+       visit_expression(*binary.left, binary.oper, false);
        append(binary.oper->token);
-       binary.right->visit(*this);
+       visit_expression(*binary.right, binary.oper, true);
        if(binary.oper->token2[0])
                append(binary.oper->token2);
 }
 
 void Formatter::visit(Assignment &assign)
 {
-       assign.left->visit(*this);
+       visit_expression(*assign.left, assign.oper, false);
        append(format(" %s ", assign.oper->token));
-       assign.right->visit(*this);
+       visit_expression(*assign.right, assign.oper, true);
 }
 
 void Formatter::visit(TernaryExpression &ternary)
 {
-       ternary.condition->visit(*this);
+       visit_expression(*ternary.condition, ternary.oper, false);
        append(ternary.oper->token);
-       ternary.true_expr->visit(*this);
+       visit_expression(*ternary.true_expr, ternary.oper, false);
        if(ternary.oper->token2)
                append(ternary.oper->token2);
-       ternary.false_expr->visit(*this);
+       visit_expression(*ternary.false_expr, ternary.oper, true);
 }
 
 void Formatter::visit(FunctionCall &call)