go/runtime.cc - gofrontend - Git at Google

 // runtime.cc -- runtime functions called by generated code

 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 #include "go-system.h"

 #include "gogo.h"
 #include "types.h"
 #include "expressions.h"
 #include "runtime.h"

 // The frontend generates calls to various runtime functions.  They
 // are implemented in libgo/runtime.  This is how the runtime
 // functions are represented in the frontend.  Note that there is
 // currently nothing which ensures that the compiler's understanding
 // of the runtime function matches the actual implementation in
 // libgo/runtime.

 // Parameter and result types used by runtime functions.

 enum Runtime_function_type
 {
   // General indicator that value is not used.
   RFT_VOID,
   // Go untyped bool, C type _Bool.
   RFT_BOOL,
   // Go type *bool, C type _Bool*.
   RFT_BOOLPTR,
   // Go type int, C type intgo.
   RFT_INT,
   // Go type int32, C type int32_t.
   RFT_INT32,
   // Go type int64, C type int64_t.
   RFT_INT64,
   // Go type uint64, C type uint64_t.
   RFT_UINT64,
   // Go type uintptr, C type uintptr_t.
   RFT_UINTPTR,
   // Go type rune, C type int32_t.
   RFT_RUNE,
   // Go type float64, C type double.
   RFT_FLOAT64,
   // Go type complex64, C type __complex float.
   RFT_COMPLEX64,
   // Go type complex128, C type __complex double.
   RFT_COMPLEX128,
   // Go type string, C type struct __go_string.
   RFT_STRING,
   // Go type unsafe.Pointer, C type "void *".
   RFT_POINTER,
   // Go type []any, C type struct __go_open_array.
   RFT_SLICE,
   // Go type map[any]any, C type struct __go_map *.
   RFT_MAP,
   // Go type chan any, C type struct __go_channel *.
   RFT_CHAN,
   // Go type non-empty interface, C type struct __go_interface.
   RFT_IFACE,
   // Go type interface{}, C type struct __go_empty_interface.
   RFT_EFACE,
   // Go type func(unsafe.Pointer), C type void (*) (void *).
   RFT_FUNC_PTR,
   // Pointer to Go type descriptor.
   RFT_TYPE,
   // [2]string.
   RFT_ARRAY2STRING,
   // [3]string.
   RFT_ARRAY3STRING,
   // [4]string.
   RFT_ARRAY4STRING,
   // [5]string.
   RFT_ARRAY5STRING,

   NUMBER_OF_RUNTIME_FUNCTION_TYPES
 };

 // The Type structures for the runtime function types.

 static Type* runtime_function_types[NUMBER_OF_RUNTIME_FUNCTION_TYPES];

 // Get the Type for a Runtime_function_type code.

 static Type*
 runtime_function_type(Runtime_function_type bft)
 {
   go_assert(bft < NUMBER_OF_RUNTIME_FUNCTION_TYPES);
   Type* any = Type::make_pointer_type(Type::make_void_type());
   if (runtime_function_types[bft] == NULL)
     {
       const Location bloc = Linemap::predeclared_location();
       Type* t;
       switch (bft)
 	{
 	default:
 	case RFT_VOID:
 	  go_unreachable();

 	case RFT_BOOL:
 	  t = Type::make_boolean_type();
 	  break;

 	case RFT_BOOLPTR:
 	  t = Type::make_pointer_type(Type::lookup_bool_type());
 	  break;

 	case RFT_INT:
 	  t = Type::lookup_integer_type("int");
 	  break;

 	case RFT_INT32:
 	  t = Type::lookup_integer_type("int32");
 	  break;

 	case RFT_INT64:
 	  t = Type::lookup_integer_type("int64");
 	  break;

 	case RFT_UINT64:
 	  t = Type::lookup_integer_type("uint64");
 	  break;

 	case RFT_RUNE:
 	  t = Type::lookup_integer_type("int32");
 	  break;

 	case RFT_UINTPTR:
 	  t = Type::lookup_integer_type("uintptr");
 	  break;

 	case RFT_FLOAT64:
 	  t = Type::lookup_float_type("float64");
 	  break;

 	case RFT_COMPLEX64:
 	  t = Type::lookup_complex_type("complex64");
 	  break;

 	case RFT_COMPLEX128:
 	  t = Type::lookup_complex_type("complex128");
 	  break;

 	case RFT_STRING:
 	  t = Type::lookup_string_type();
 	  break;

 	case RFT_POINTER:
 	  t = Type::make_pointer_type(Type::make_void_type());
 	  break;

 	case RFT_SLICE:
 	  t = Type::make_array_type(any, NULL);
 	  break;

 	case RFT_MAP:
 	  t = Type::make_map_type(any, any, bloc);
 	  break;

 	case RFT_CHAN:
 	  t = Type::make_channel_type(true, true, any);
 	  break;

 	case RFT_IFACE:
 	  {
 	    Typed_identifier_list* methods = new Typed_identifier_list();
 	    Type* mtype = Type::make_function_type(NULL, NULL, NULL, bloc);
 	    methods->push_back(Typed_identifier("x", mtype, bloc));
 	    Interface_type* it = Type::make_interface_type(methods, bloc);
 	    it->finalize_methods();
 	    t = it;
 	  }
 	  break;

 	case RFT_EFACE:
 	  t = Type::make_empty_interface_type(bloc);
 	  break;

 	case RFT_FUNC_PTR:
 	  {
 	    Typed_identifier_list* param_types = new Typed_identifier_list();
 	    Type* ptrtype = runtime_function_type(RFT_POINTER);
 	    param_types->push_back(Typed_identifier("", ptrtype, bloc));
 	    t = Type::make_function_type(NULL, param_types, NULL, bloc);
 	  }
 	  break;

 	case RFT_TYPE:
 	  t = Type::make_type_descriptor_ptr_type();
 	  break;

 	case RFT_ARRAY2STRING:
 	  {
 	    Array_type* at =
 	      Type::make_array_type(Type::make_string_type(),
 				    Expression::make_integer_ul(2, NULL,
 								bloc));
 	    at->set_is_array_incomparable();
 	    t = at;
 	  }
 	  break;

 	case RFT_ARRAY3STRING:
 	  {
 	    Array_type* at =
 	      Type::make_array_type(Type::make_string_type(),
 				    Expression::make_integer_ul(3, NULL,
 								bloc));
 	    at->set_is_array_incomparable();
 	    t = at;
 	  }
 	  break;

 	case RFT_ARRAY4STRING:
 	  {
 	    Array_type* at =
 	      Type::make_array_type(Type::make_string_type(),
 				    Expression::make_integer_ul(4, NULL,
 								bloc));
 	    at->set_is_array_incomparable();
 	    t = at;
 	  }
 	  break;

 	case RFT_ARRAY5STRING:
 	  {
 	    Array_type* at =
 	      Type::make_array_type(Type::make_string_type(),
 				    Expression::make_integer_ul(5, NULL,
 								bloc));
 	    at->set_is_array_incomparable();
 	    t = at;
 	  }
 	  break;
 	}

       runtime_function_types[bft] = t;
     }

   return runtime_function_types[bft];
 }

 // Convert an expression to the type to pass to a runtime function.

 static Expression*
 convert_to_runtime_function_type(Runtime_function_type bft, Expression* e,
 				 Location loc)
 {
   switch (bft)
     {
     default:
     case RFT_VOID:
       go_unreachable();

     case RFT_BOOL:
     case RFT_BOOLPTR:
     case RFT_INT:
     case RFT_INT32:
     case RFT_INT64:
     case RFT_UINT64:
     case RFT_UINTPTR:
     case RFT_RUNE:
     case RFT_FLOAT64:
     case RFT_COMPLEX64:
     case RFT_COMPLEX128:
     case RFT_STRING:
     case RFT_POINTER:
     case RFT_FUNC_PTR:
       {
 	Type* t = runtime_function_type(bft);
 	if (!Type::are_identical(t, e->type(), true, NULL))
 	  e = Expression::make_cast(t, e, loc);
 	return e;
       }

     case RFT_SLICE:
     case RFT_MAP:
     case RFT_CHAN:
     case RFT_IFACE:
     case RFT_EFACE:
     case RFT_ARRAY2STRING:
     case RFT_ARRAY3STRING:
     case RFT_ARRAY4STRING:
     case RFT_ARRAY5STRING:
       return Expression::make_unsafe_cast(runtime_function_type(bft), e, loc);

     case RFT_TYPE:
       go_assert(e->type() == Type::make_type_descriptor_ptr_type());
       return e;
     }
 }

 // Convert all the types used for runtime functions to the backend
 // representation.

 void
 Runtime::convert_types(Gogo* gogo)
 {
   for (int i = 0; i < static_cast<int>(NUMBER_OF_RUNTIME_FUNCTION_TYPES); ++i)
     {
       Type* t = runtime_function_types[i];
       if (t != NULL && t->named_type() != NULL)
 	{
 	  bool r = t->verify();
 	  go_assert(r);
 	  t->named_type()->convert(gogo);
 	}
     }
 }

 // The type used to define a runtime function.

 struct Runtime_function
 {
   // Function name.
   const char* name;
   // Parameter types.  Never more than 6, as it happens.  RFT_VOID if
   // not used.
   Runtime_function_type parameter_types[6];
   // Result types.  Never more than 2, as it happens.  RFT_VOID if not
   // used.
   Runtime_function_type result_types[2];
 };

 static const Runtime_function runtime_functions[] =
 {

 #define DEF_GO_RUNTIME(CODE, NAME, PARAMS, RESULTS) { NAME, PARAMS, RESULTS } ,

 #include "runtime.def"

 #undef DEF_GO_RUNTIME

 };

 static Named_object*
 runtime_function_declarations[Runtime::NUMBER_OF_FUNCTIONS];

 // Get the declaration of a runtime function.

 Named_object*
 Runtime::runtime_declaration(Function code)
 {
   go_assert(code < Runtime::NUMBER_OF_FUNCTIONS);
   if (runtime_function_declarations[code] == NULL)
     {
       const Runtime_function* pb = &runtime_functions[code];

       Location bloc = Linemap::predeclared_location();

       Typed_identifier_list* param_types = NULL;
       if (pb->parameter_types[0] != RFT_VOID)
 	{
 	  param_types = new Typed_identifier_list();
 	  for (unsigned int i = 0;
 	       i < (sizeof(pb->parameter_types)
 		    / sizeof (pb->parameter_types[0]));
 	       i++)
 	    {
 	      if (pb->parameter_types[i] == RFT_VOID)
 		break;
 	      Type* t = runtime_function_type(pb->parameter_types[i]);
 	      param_types->push_back(Typed_identifier("", t, bloc));
 	    }
 	}

       Typed_identifier_list* result_types = NULL;
       if (pb->result_types[0] != RFT_VOID)
 	{
 	  result_types = new Typed_identifier_list();
 	  for (unsigned int i = 0;
 	       i < sizeof(pb->result_types) / sizeof(pb->result_types[0]);
 	       i++)
 	    {
 	      if (pb->result_types[i] == RFT_VOID)
 		break;
 	      Type* t = runtime_function_type(pb->result_types[i]);
 	      result_types->push_back(Typed_identifier("", t, bloc));
 	    }
 	}

       Function_type* fntype = Type::make_function_type(NULL, param_types,
 						       result_types, bloc);
       const char* n = pb->name;
       const char* n1 = strchr(n, '.');
       if (n1 != NULL)
 	n = n1 + 1;
       Named_object* no = Named_object::make_function_declaration(n, NULL,
 								 fntype, bloc);
       no->func_declaration_value()->set_asm_name(pb->name);

       runtime_function_declarations[code] = no;
     }

   return runtime_function_declarations[code];
 }

 // Make a call to a runtime function.

 Call_expression*
 Runtime::make_call(Runtime::Function code, Location loc,
 		   int param_count, ...)
 {
   go_assert(code < Runtime::NUMBER_OF_FUNCTIONS);

   const Runtime_function* pb = &runtime_functions[code];

   go_assert(static_cast<size_t>(param_count)
 	     <= sizeof(pb->parameter_types) / sizeof(pb->parameter_types[0]));

   Named_object* no = runtime_declaration(code);
   Expression* func = Expression::make_func_reference(no, NULL, loc);

   Expression_list* args = new Expression_list();
   args->reserve(param_count);

   va_list ap;
   va_start(ap, param_count);
   for (int i = 0; i < param_count; ++i)
     {
       Expression* e = va_arg(ap, Expression*);
       Runtime_function_type rft = pb->parameter_types[i];
       args->push_back(convert_to_runtime_function_type(rft, e, loc));
     }
   va_end(ap);

   return Expression::make_call(func, args, false, loc);
 }

 // Get the runtime code for a named builtin function.  This is used as a helper
 // when creating function references for call expressions.  Every reference to
 // a builtin runtime function should have the associated runtime code.  If the
 // name is ambiguous and can refer to many runtime codes, return
 // NUMBER_OF_FUNCTIONS.

 Runtime::Function
 Runtime::name_to_code(const std::string& name)
 {
   Function code = Runtime::NUMBER_OF_FUNCTIONS;

   // Aliases seen in function declaration code.
   // TODO(cmang): Add other aliases.
   if (name == "new")
     code = Runtime::NEW;
   else if (name == "close")
     code = Runtime::CLOSE;
   else if (name == "copy")
     code = Runtime::SLICECOPY;
   else if (name == "append")
     code = Runtime::GROWSLICE;
   else if (name == "delete")
     code = Runtime::MAPDELETE;
   else
     {
       // Look through the known names for a match.
       for (size_t i = 0; i < Runtime::NUMBER_OF_FUNCTIONS; i++)
 	{
 	  if (strcmp(runtime_functions[i].name, name.c_str()) == 0)
 	    code = static_cast<Runtime::Function>(i);
 	}
     }
   return code;
 }
	// runtime.cc -- runtime functions called by generated code

	// Copyright 2011 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	#include "go-system.h"

	#include "gogo.h"
	#include "types.h"
	#include "expressions.h"
	#include "runtime.h"

	// The frontend generates calls to various runtime functions. They
	// are implemented in libgo/runtime. This is how the runtime
	// functions are represented in the frontend. Note that there is
	// currently nothing which ensures that the compiler's understanding
	// of the runtime function matches the actual implementation in
	// libgo/runtime.

	// Parameter and result types used by runtime functions.

	enum Runtime_function_type
	{
	// General indicator that value is not used.
	RFT_VOID,
	// Go untyped bool, C type _Bool.
	RFT_BOOL,
	// Go type bool, C type _Bool.
	RFT_BOOLPTR,
	// Go type int, C type intgo.
	RFT_INT,
	// Go type int32, C type int32_t.
	RFT_INT32,
	// Go type int64, C type int64_t.
	RFT_INT64,
	// Go type uint64, C type uint64_t.
	RFT_UINT64,
	// Go type uintptr, C type uintptr_t.
	RFT_UINTPTR,
	// Go type rune, C type int32_t.
	RFT_RUNE,
	// Go type float64, C type double.
	RFT_FLOAT64,
	// Go type complex64, C type __complex float.
	RFT_COMPLEX64,
	// Go type complex128, C type __complex double.
	RFT_COMPLEX128,
	// Go type string, C type struct __go_string.
	RFT_STRING,
	// Go type unsafe.Pointer, C type "void *".
	RFT_POINTER,
	// Go type []any, C type struct __go_open_array.
	RFT_SLICE,
	// Go type map[any]any, C type struct __go_map *.
	RFT_MAP,
	// Go type chan any, C type struct __go_channel *.
	RFT_CHAN,
	// Go type non-empty interface, C type struct __go_interface.
	RFT_IFACE,
	// Go type interface{}, C type struct __go_empty_interface.
	RFT_EFACE,
	// Go type func(unsafe.Pointer), C type void () (void ).
	RFT_FUNC_PTR,
	// Pointer to Go type descriptor.
	RFT_TYPE,
	// [2]string.
	RFT_ARRAY2STRING,
	// [3]string.
	RFT_ARRAY3STRING,
	// [4]string.
	RFT_ARRAY4STRING,
	// [5]string.
	RFT_ARRAY5STRING,

	NUMBER_OF_RUNTIME_FUNCTION_TYPES
	};

	// The Type structures for the runtime function types.

	static Type* runtime_function_types[NUMBER_OF_RUNTIME_FUNCTION_TYPES];

	// Get the Type for a Runtime_function_type code.

	static Type*
	runtime_function_type(Runtime_function_type bft)
	{
	go_assert(bft < NUMBER_OF_RUNTIME_FUNCTION_TYPES);
	Type* any = Type::make_pointer_type(Type::make_void_type());
	if (runtime_function_types[bft] == NULL)
	{
	const Location bloc = Linemap::predeclared_location();
	Type* t;
	switch (bft)
	{
	default:
	case RFT_VOID:
	go_unreachable();

	case RFT_BOOL:
	t = Type::make_boolean_type();
	break;

	case RFT_BOOLPTR:
	t = Type::make_pointer_type(Type::lookup_bool_type());
	break;

	case RFT_INT:
	t = Type::lookup_integer_type("int");
	break;

	case RFT_INT32:
	t = Type::lookup_integer_type("int32");
	break;

	case RFT_INT64:
	t = Type::lookup_integer_type("int64");
	break;

	case RFT_UINT64:
	t = Type::lookup_integer_type("uint64");
	break;

	case RFT_RUNE:
	t = Type::lookup_integer_type("int32");
	break;

	case RFT_UINTPTR:
	t = Type::lookup_integer_type("uintptr");
	break;

	case RFT_FLOAT64:
	t = Type::lookup_float_type("float64");
	break;

	case RFT_COMPLEX64:
	t = Type::lookup_complex_type("complex64");
	break;

	case RFT_COMPLEX128:
	t = Type::lookup_complex_type("complex128");
	break;

	case RFT_STRING:
	t = Type::lookup_string_type();
	break;

	case RFT_POINTER:
	t = Type::make_pointer_type(Type::make_void_type());
	break;

	case RFT_SLICE:
	t = Type::make_array_type(any, NULL);
	break;

	case RFT_MAP:
	t = Type::make_map_type(any, any, bloc);
	break;

	case RFT_CHAN:
	t = Type::make_channel_type(true, true, any);
	break;

	case RFT_IFACE:
	{
	Typed_identifier_list* methods = new Typed_identifier_list();
	Type* mtype = Type::make_function_type(NULL, NULL, NULL, bloc);
	methods->push_back(Typed_identifier("x", mtype, bloc));
	Interface_type* it = Type::make_interface_type(methods, bloc);
	it->finalize_methods();
	t = it;
	}
	break;

	case RFT_EFACE:
	t = Type::make_empty_interface_type(bloc);
	break;

	case RFT_FUNC_PTR:
	{
	Typed_identifier_list* param_types = new Typed_identifier_list();
	Type* ptrtype = runtime_function_type(RFT_POINTER);
	param_types->push_back(Typed_identifier("", ptrtype, bloc));
	t = Type::make_function_type(NULL, param_types, NULL, bloc);
	}
	break;

	case RFT_TYPE:
	t = Type::make_type_descriptor_ptr_type();
	break;

	case RFT_ARRAY2STRING:
	{
	Array_type* at =
	Type::make_array_type(Type::make_string_type(),
	Expression::make_integer_ul(2, NULL,
	bloc));
	at->set_is_array_incomparable();
	t = at;
	}
	break;

	case RFT_ARRAY3STRING:
	{
	Array_type* at =
	Type::make_array_type(Type::make_string_type(),
	Expression::make_integer_ul(3, NULL,
	bloc));
	at->set_is_array_incomparable();
	t = at;
	}
	break;

	case RFT_ARRAY4STRING:
	{
	Array_type* at =
	Type::make_array_type(Type::make_string_type(),
	Expression::make_integer_ul(4, NULL,
	bloc));
	at->set_is_array_incomparable();
	t = at;
	}
	break;

	case RFT_ARRAY5STRING:
	{
	Array_type* at =
	Type::make_array_type(Type::make_string_type(),
	Expression::make_integer_ul(5, NULL,
	bloc));
	at->set_is_array_incomparable();
	t = at;
	}
	break;
	}

	runtime_function_types[bft] = t;
	}

	return runtime_function_types[bft];
	}

	// Convert an expression to the type to pass to a runtime function.

	static Expression*
	convert_to_runtime_function_type(Runtime_function_type bft, Expression* e,
	Location loc)
	{
	switch (bft)
	{
	default:
	case RFT_VOID:
	go_unreachable();

	case RFT_BOOL:
	case RFT_BOOLPTR:
	case RFT_INT:
	case RFT_INT32:
	case RFT_INT64:
	case RFT_UINT64:
	case RFT_UINTPTR:
	case RFT_RUNE:
	case RFT_FLOAT64:
	case RFT_COMPLEX64:
	case RFT_COMPLEX128:
	case RFT_STRING:
	case RFT_POINTER:
	case RFT_FUNC_PTR:
	{
	Type* t = runtime_function_type(bft);
	if (!Type::are_identical(t, e->type(), true, NULL))
	e = Expression::make_cast(t, e, loc);
	return e;
	}

	case RFT_SLICE:
	case RFT_MAP:
	case RFT_CHAN:
	case RFT_IFACE:
	case RFT_EFACE:
	case RFT_ARRAY2STRING:
	case RFT_ARRAY3STRING:
	case RFT_ARRAY4STRING:
	case RFT_ARRAY5STRING:
	return Expression::make_unsafe_cast(runtime_function_type(bft), e, loc);

	case RFT_TYPE:
	go_assert(e->type() == Type::make_type_descriptor_ptr_type());
	return e;
	}
	}

	// Convert all the types used for runtime functions to the backend
	// representation.

	void
	Runtime::convert_types(Gogo* gogo)
	{
	for (int i = 0; i < static_cast<int>(NUMBER_OF_RUNTIME_FUNCTION_TYPES); ++i)
	{
	Type* t = runtime_function_types[i];
	if (t != NULL && t->named_type() != NULL)
	{
	bool r = t->verify();
	go_assert(r);
	t->named_type()->convert(gogo);
	}
	}
	}

	// The type used to define a runtime function.

	struct Runtime_function
	{
	// Function name.
	const char* name;
	// Parameter types. Never more than 6, as it happens. RFT_VOID if
	// not used.
	Runtime_function_type parameter_types[6];
	// Result types. Never more than 2, as it happens. RFT_VOID if not
	// used.
	Runtime_function_type result_types[2];
	};

	static const Runtime_function runtime_functions[] =
	{

	#define DEF_GO_RUNTIME(CODE, NAME, PARAMS, RESULTS) { NAME, PARAMS, RESULTS } ,

	#include "runtime.def"

	#undef DEF_GO_RUNTIME

	};

	static Named_object*
	runtime_function_declarations[Runtime::NUMBER_OF_FUNCTIONS];

	// Get the declaration of a runtime function.

	Named_object*
	Runtime::runtime_declaration(Function code)
	{
	go_assert(code < Runtime::NUMBER_OF_FUNCTIONS);
	if (runtime_function_declarations[code] == NULL)
	{
	const Runtime_function* pb = &runtime_functions[code];

	Location bloc = Linemap::predeclared_location();

	Typed_identifier_list* param_types = NULL;
	if (pb->parameter_types[0] != RFT_VOID)
	{
	param_types = new Typed_identifier_list();
	for (unsigned int i = 0;
	i < (sizeof(pb->parameter_types)
	/ sizeof (pb->parameter_types[0]));
	i++)
	{
	if (pb->parameter_types[i] == RFT_VOID)
	break;
	Type* t = runtime_function_type(pb->parameter_types[i]);
	param_types->push_back(Typed_identifier("", t, bloc));
	}
	}

	Typed_identifier_list* result_types = NULL;
	if (pb->result_types[0] != RFT_VOID)
	{
	result_types = new Typed_identifier_list();
	for (unsigned int i = 0;
	i < sizeof(pb->result_types) / sizeof(pb->result_types[0]);
	i++)
	{
	if (pb->result_types[i] == RFT_VOID)
	break;
	Type* t = runtime_function_type(pb->result_types[i]);
	result_types->push_back(Typed_identifier("", t, bloc));
	}
	}

	Function_type* fntype = Type::make_function_type(NULL, param_types,
	result_types, bloc);
	const char* n = pb->name;
	const char* n1 = strchr(n, '.');
	if (n1 != NULL)
	n = n1 + 1;
	Named_object* no = Named_object::make_function_declaration(n, NULL,
	fntype, bloc);
	no->func_declaration_value()->set_asm_name(pb->name);

	runtime_function_declarations[code] = no;
	}

	return runtime_function_declarations[code];
	}

	// Make a call to a runtime function.

	Call_expression*
	Runtime::make_call(Runtime::Function code, Location loc,
	int param_count, ...)
	{
	go_assert(code < Runtime::NUMBER_OF_FUNCTIONS);

	const Runtime_function* pb = &runtime_functions[code];

	go_assert(static_cast<size_t>(param_count)
	<= sizeof(pb->parameter_types) / sizeof(pb->parameter_types[0]));

	Named_object* no = runtime_declaration(code);
	Expression* func = Expression::make_func_reference(no, NULL, loc);

	Expression_list* args = new Expression_list();
	args->reserve(param_count);

	va_list ap;
	va_start(ap, param_count);
	for (int i = 0; i < param_count; ++i)
	{
	Expression* e = va_arg(ap, Expression*);
	Runtime_function_type rft = pb->parameter_types[i];
	args->push_back(convert_to_runtime_function_type(rft, e, loc));
	}
	va_end(ap);

	return Expression::make_call(func, args, false, loc);
	}

	// Get the runtime code for a named builtin function. This is used as a helper
	// when creating function references for call expressions. Every reference to
	// a builtin runtime function should have the associated runtime code. If the
	// name is ambiguous and can refer to many runtime codes, return
	// NUMBER_OF_FUNCTIONS.

	Runtime::Function
	Runtime::name_to_code(const std::string& name)
	{
	Function code = Runtime::NUMBER_OF_FUNCTIONS;

	// Aliases seen in function declaration code.
	// TODO(cmang): Add other aliases.
	if (name == "new")
	code = Runtime::NEW;
	else if (name == "close")
	code = Runtime::CLOSE;
	else if (name == "copy")
	code = Runtime::SLICECOPY;
	else if (name == "append")
	code = Runtime::GROWSLICE;
	else if (name == "delete")
	code = Runtime::MAPDELETE;
	else
	{
	// Look through the known names for a match.
	for (size_t i = 0; i < Runtime::NUMBER_OF_FUNCTIONS; i++)
	{
	if (strcmp(runtime_functions[i].name, name.c_str()) == 0)
	code = static_cast<Runtime::Function>(i);
	}
	}
	return code;
	}