Function PatchShader

shadercompiler/EffectCompilerMetal.cpp:2704–3037

Creates a new shader functions with all the inputs/outputs layed out for Metal: - all [[stage_in]] inputs are put into a new flat struct - all outputs are put into a new struct - uniform arguments are moved to local variables inside the shader - all the other arguments from the original entry point are passed as is Returns new entry point function definition (added to AST root)

// - all the other arguments from the original entry point are passed as is
// Returns new entry point function definition (added to AST root)
ASTNode* PatchShader( PatchShaderType shaderType, ASTNode* callNode, ParserState& state )
{
	ZoneScoped;

	Symbol* entryPointSymbol = callNode->GetSymbol();
	if( !entryPointSymbol || !entryPointSymbol->definition )
	{
		return nullptr;
	}

	ASTNode* functionHeader = entryPointSymbol->definition->GetChildOrNull( 0 );
	if( !functionHeader )
	{
		return nullptr;
	}

	ScannerToken shaderName = ScannerToken::ID( GetEntryPointName( shaderType, callNode ) );

	state.GetCurrentLocation().fileName = shaderName.stringValue;
	state.GetCurrentLocation().lineNumber = 1;

	ASTNode* inputsStruct = NewStruct( state, state.AllocateNameWithPrefix( "StageInData" ) );
	ASTNode* outputsStruct = NewStruct( state, state.AllocateNameWithPrefix( "StageOutData" ) );

	auto header = state.NewNode( NT_FUNCTION_HEADER, shaderName );
	auto shaderSymbol = state.GetSymbolTable().AddSymbol( shaderName.stringValue, ALLOW_OVERRIDES );
	shaderSymbol->isFunction = true;
	header->SetSymbol( shaderSymbol );

	state.GetSymbolTable().EnterScope();

	auto shaderBody = state.NewNode( NT_BLOCK );

	std::vector<Symbol*> params;

	size_t uniformArgIndex = 0;

	for( size_t i = 0; i < functionHeader->GetChildrenCount(); ++i )
	{
		// Create local variable declarations for original shader function arguments

		ASTNode* sourceArg = functionHeader->GetChild( i );
		Symbol* sourceSymbol = sourceArg->GetSymbol();
		ASTNode* bracketList = sourceArg->GetChildOrNull( 0 );

		if( sourceSymbol->addressSpace != AddressSpace::Threadgroup &&
			!IsUniformInputArgument( sourceArg ) &&
			( ( !sourceArg->GetType().IsStruct() && !sourceArg->GetType().IsScalarOrVector() ) ||
			  sourceSymbol->addressSpace != AddressSpace::None ||
			  HasSystemRegister( sourceSymbol ) ) )
		{
			params.push_back( nullptr );
			continue;
		}

		auto isUniform = IsUniformInputArgument( sourceArg );
		if( shaderType >= PatchShaderType::RAY_GEN && !isUniform )
		{