Parser - Local variable declarations

.vim.local/syntax/demo-srd.vim

@@ -36,7 +36,7 @@ syn keyword srdTodo		contained TODO TODO: FIXME FIXME: XXX XXX:
 " ------------------------------------------------------------------------------
 " Keywords
 
-syn keyword srdKWFlow		if set call fn init frame
+syn keyword srdKWFlow		if set call fn init frame locals
 
 syn keyword srdKWDefAsset	program pipeline input framebuffer texture sampler
 

demo.srd

@@ -287,9 +287,10 @@
 )
 
 (fn bloom-downsample (target level)
-	(locals w h)
-	(set w (div $vp-width (pow 2 $level)))
-	(set h (div $vp-height (pow 2 $level)))
+	(locals m w h)
+	(set m (inv (pow 2 $level)))
+	(set w (mul $vp-width $m))
+	(set h (mul $vp-height $m))
 
 	(use-pipeline pl-bloom-downsample)
 	(use-framebuffer target)

opast.cc

@@ -101,7 +101,7 @@ A_Node* opast::ASTVisitorBrowser(
 	    //
 	    case A_Node::OP_PROGRAM: case A_Node::OP_PIPELINE:
 	    case A_Node::OP_INPUT: case A_Node::OP_FULLSCREEN:
-	    case A_Node::OP_ODBG:
+	    case A_Node::OP_ODBG: case A_Node::OP_LOCALS:
 	    //
 	    case A_Node::OP_USE_FRAMEBUFFER: case A_Node::OP_USE_PIPELINE:
 	    case A_Node::OP_USE_PROGRAM: case A_Node::OP_USE_TEXTURE:
@@ -174,7 +174,7 @@ A_Node* opast::ASTVisitorBrowser(
 			}
 			c --;
 		}
-		return n.lods( );
+		return c == 0 ? n.lods( ) : nullptr;
 	    }
 
 	    // Framebuffer definition; may have LOD expressions
@@ -191,7 +191,7 @@ A_Node* opast::ASTVisitorBrowser(
 				c --;
 			}
 		}
-		if ( c == 0 && n.depthAttachmentLOD( ) ) {
+		if ( c == 0 && n.hasDepthAttachment( ) ) {
 			return n.depthAttachmentLOD( );
 		}
 		break;
@@ -497,3 +497,16 @@ T_Optional< T_SRDLocation > T_SamplerInstrNode::setLOD(
 	lod_ = T_LOD_{ location , std::move( min ) , std::move( max ) };
 	return {};
 }
+
+/*= T_LocalsInstrNode ===========================================================*/
+
+bool T_LocalsInstrNode::addVariable(
+		T_SRDToken const& token ) noexcept
+{
+	if ( vars_.contains( token.stringValue( ) ) ) {
+		return false;
+	}
+	vars_.add( token.stringValue( ) );
+	varLocs_.add( token.location( ) );
+	return true;
+}

opast.hh

@@ -25,6 +25,7 @@ class A_Node
 		OP_FRAMEBUFFER ,// Define framebuffer
 		OP_FULLSCREEN ,	// Draw a fullscreen quad
 		OP_INPUT ,	// Input declaration
+		OP_LOCALS ,	// Declare local variables
 		OP_ODBG ,	// Output debugging
 		OP_PIPELINE ,	// Shader pipeline declaration
 		OP_PROFILE ,	// Profiling block
@@ -484,6 +485,32 @@ class T_InputInstrNode : public A_InstructionNode
 		{ return dvLocation_; }
 };
 
+// Local variable declarations
+class T_LocalsInstrNode : public A_InstructionNode
+{
+    private:
+	T_AutoArray< T_String , 8 > vars_;
+	T_AutoArray< T_SRDLocation , 8 > varLocs_;
+
+    public:
+	T_LocalsInstrNode( T_InstrListNode& parent ) noexcept
+		: A_InstructionNode( OP_LOCALS , parent )
+	{ }
+
+	bool addVariable( T_SRDToken const& token ) noexcept;
+
+	uint32_t variables( ) const noexcept
+		{ return vars_.size( ); }
+
+	T_String const& varName(
+			const uint32_t index ) const noexcept
+	{ return vars_[ index ]; }
+
+	T_SRDLocation const& varLocation(
+			const uint32_t index ) const noexcept
+	{ return varLocs_[ index ]; }
+};
+
 // Output debugging
 class T_OutputDebugInstrNode : public A_InstructionNode
 {

opparser.cc

@@ -18,6 +18,7 @@ struct T_ParserImpl_
 		FULLSCREEN ,
 		IF ,
 		INPUT ,
+		LOCALS ,
 		ODBG ,
 		PIPELINE ,
 		PROFILE ,
@@ -45,6 +46,7 @@ struct T_ParserImpl_
 		add( "fullscreen" , E_InstrType::FULLSCREEN );
 		add( "if" , E_InstrType::IF );
 		add( "input" , E_InstrType::INPUT );
+		add( "locals" , E_InstrType::LOCALS );
 		add( "odbg" , E_InstrType::ODBG );
 		add( "pipeline" , E_InstrType::PIPELINE );
 		add( "profiling" , E_InstrType::PROFILE );
@@ -191,6 +193,7 @@ struct T_ParserImpl_
 
 	M_DPARSER_( If );
 	M_DPARSER_( Input );
+	M_DPARSER_( Local );
 	M_DPARSER_( ODebug );
 	M_DPARSER_( Pipeline );
 	M_DPARSER_( Profile );
@@ -486,6 +489,7 @@ void T_ParserImpl_::parseInstructions(
 			M_CASE_( FRAMEBUFFER , Framebuffer );
 			M_CASE_( IF , If );
 			M_CASE_( INPUT , Input );
+			M_CASE_( LOCALS , Local );
 			M_CASE_( ODBG , ODebug );
 			M_CASE_( PIPELINE , Pipeline );
 			M_CASE_( PROFILE , Profile );
@@ -684,6 +688,31 @@ M_INSTR_( Input )
 
 /*----------------------------------------------------------------------------*/
 
+M_INSTR_( Local )
+{
+	const auto ni( input.size( ) );
+	if ( ni < 2 ) {
+		errors.addNew( "variable identifier expected" , input[ 0 ].location( ) );
+		return;
+	}
+
+	auto& instr{ instructions.add< T_LocalsInstrNode >( ) };
+	instr.location( ) = input[ 0 ].location( );
+
+	for ( auto i = 1u ; i < ni ; i ++ ) {
+		auto const& token( input[ i ] );
+		if ( token.type( ) != E_SRDTokenType::WORD ) {
+			errors.addNew( "variable identifier expected" ,
+					token.location( ) );
+		} else if ( !instr.addVariable( token ) ) {
+			errors.addNew( "duplicate variable identifier" ,
+					token.location( ) );
+		}
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
 M_INSTR_( ODebug )
 {
 	const auto ni( input.size( ) );