quakeforge/tools/qfcc/source/expr.c

/*
	#FILENAME#

	#DESCRIPTION#

	Copyright (C) 2001 #AUTHOR#

	Author: #AUTHOR#
	Date: #DATE#

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

	See the GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
static const char rcsid[] =
	"$Id$";

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdlib.h>

#include <QF/dstring.h>
#include <QF/mathlib.h>
#include <QF/sys.h>
#include <QF/va.h>

#include "qfcc.h"
#include "class.h"
#include "def.h"
#include "expr.h"
#include "function.h"
#include "idstuff.h"
#include "immediate.h"
#include "method.h"
#include "options.h"
#include "struct.h"
#include "type.h"
#include "qc-parse.h"

static expr_t *free_exprs;
int         lineno_base;

etype_t     qc_types[] = {
	ev_void,							// ex_error
	ev_void,							// ex_label
	ev_void,							// ex_block
	ev_void,							// ex_expr
	ev_void,							// ex_uexpr
	ev_void,							// ex_def
	ev_void,							// ex_temp
	ev_void,							// ex_nil
	ev_void,							// ex_name

	ev_string,							// ex_string
	ev_float,							// ex_float
	ev_vector,							// ex_vector
	ev_entity,							// ex_entity
	ev_field,							// ex_field
	ev_func,							// ex_func
	ev_pointer,							// ex_pointer
	ev_quaternion,						// ex_quaternion
	ev_integer,							// ex_integer
	ev_uinteger,						// ex_uinteger
	ev_short,							// ex_short
};

type_t     *types[] = {
	&type_void,
	&type_string,
	&type_float,
	&type_vector,
	&type_entity,
	&type_field,
	&type_function,
	&type_pointer,
	&type_quaternion,
	&type_integer,
	&type_uinteger,
	&type_short,
	&type_void,							// FIXME what type?
	&type_void,							// FIXME what type?
	&type_void,							// FIXME what type?
	&type_SEL,
	&type_void,							// FIXME what type?
};

expr_type   expr_types[] = {
	ex_nil,								// ev_void
	ex_string,							// ev_string
	ex_float,							// ev_float
	ex_vector,							// ev_vector
	ex_entity,							// ev_entity
	ex_field,							// ev_field
	ex_func,							// ev_func
	ex_pointer,							// ev_pointer
	ex_quaternion,						// ev_quaternion
	ex_integer,							// ev_integer
	ex_uinteger,						// ev_uinteger
	ex_short,							// ev_short
	ex_nil,								// ev_struct
	ex_nil,								// ev_object
	ex_nil,								// ev_class
	ex_nil,								// ev_sel
	ex_nil,								// ev_array
};

void
convert_name (expr_t *e)
{
	if (e->type == ex_name) {
		const char *name = e->e.string_val;
		def_t      *d;
		expr_t     *new;
		class_t    *class;

		class = get_class (name, 0);
		if (class) {
			e->type = ex_def;
			e->e.def = class_pointer_def (class);
			return;
		}
		d = get_def (NULL, name, current_scope, st_none);
		if (d) {
			if (d->global) {
				new = class_ivar_expr (current_class, name);
				if (new)
					goto convert;
			}
			e->type = ex_def;
			e->e.def = d;
			return;
		}
		new = class_ivar_expr (current_class, name);
		if (new)
			goto convert;
		new = get_enum (name);
		if (new)
			goto convert;
		error (e, "Undeclared variable \"%s\".", name);
		return;
	  convert:
		e->type = new->type;
		e->e = new->e;
	}
}

type_t *
get_type (expr_t *e)
{
	convert_name (e);
	switch (e->type) {
		case ex_label:
		case ex_name:
		case ex_error:
			return 0;					// something went very wrong
		case ex_nil:
			return &type_void;
		case ex_block:
			if (e->e.block.result)
				return get_type (e->e.block.result);
			return &type_void;
		case ex_expr:
		case ex_uexpr:
			return e->e.expr.type;
		case ex_def:
			return e->e.def->type;
		case ex_temp:
			return e->e.temp.type;
		case ex_pointer:
			return pointer_type (e->e.pointer.type);
		case ex_integer:
			if (options.code.progsversion == PROG_ID_VERSION) {
				e->type = ex_float;
				e->e.float_val = e->e.integer_val;
			}
			// fall through
		case ex_string:
		case ex_float:
		case ex_vector:
		case ex_entity:
		case ex_field:
		case ex_func:
		case ex_quaternion:
		case ex_uinteger:
		case ex_short:
			return types[qc_types[e->type]];
	}
	return 0;
}

etype_t
extract_type (expr_t *e)
{
	type_t     *type = get_type (e);

	if (type)
		return type->type;
	return ev_type_count;
}

expr_t *
error (expr_t *e, const char *fmt, ...)
{
	va_list     args;
	string_t    file = s_file;
	int         line = pr_source_line;

	va_start (args, fmt);
	if (e) {
		file = e->file;
		line = e->line;
	}
	fprintf (stderr, "%s:%d: ", pr.strings + file, line);
	vfprintf (stderr, fmt, args);
	fputs ("\n", stderr);
	va_end (args);
	pr_error_count++;

	if (e) {
		e->type = ex_error;
	}
	return e;
}

void
_warning (expr_t *e, const char *fmt, va_list args)
{
	string_t    file = s_file;
	int         line = pr_source_line;

	if (options.warnings.promote) {
		options.warnings.promote = 0;	// only want to do this once
		fprintf (stderr, "%s: warnings treated as errors\n", "qfcc");
		pr_error_count++;
	}

	if (e) {
		file = e->file;
		line = e->line;
	}
	fprintf (stderr, "%s:%d: warning: ", pr.strings + file, line);
	vfprintf (stderr, fmt, args);
	fputs ("\n", stderr);
}

void
warning (expr_t *e, const char *fmt, ...)
{
	va_list     args;

	va_start (args, fmt);
	_warning (e, fmt, args);
	va_end (args);
}

void
notice (expr_t *e, const char *fmt, ...)
{
	va_list     args;

	if (options.notices.silent)
		return;

	va_start (args, fmt);
	if (options.notices.promote) {
		_warning (e, fmt, args);
	} else {
		string_t    file = s_file;
		int         line = pr_source_line;

		if (e) {
			file = e->file;
			line = e->line;
		}
		fprintf (stderr, "%s:%d: notice: ", pr.strings + file, line);
		vfprintf (stderr, fmt, args);
		fputs ("\n", stderr);
	}
	va_end (args);
}

const char *
get_op_string (int op)
{
	switch (op) {
		case PAS:	return ".=";
		case OR:	return "||";
		case AND:	return "&&";
		case EQ:	return "==";
		case NE:	return "!=";
		case LE:	return "<=";
		case GE:	return ">=";
		case LT:	return "<";
		case GT:	return ">";
		case '=':	return "=";
		case '+':	return "+";
		case '-':	return "-";
		case '*':	return "*";
		case '/':	return "/";
		case '%':	return "%";
		case '&':	return "&";
		case '|':	return "|";
		case '^':	return "^";
		case '~':	return "~";
		case '!':	return "!";
		case SHL:	return "<<";
		case SHR:	return ">>";
		case '.':	return ".";
		case 'i':	return "<if>";
		case 'n':	return "<ifnot>";
		case IFBE:	return "<ifbe>";
		case IFB:	return "<ifb>";
		case IFAE:	return "<ifae>";
		case IFA:	return "<ifa>";
		case 'g':	return "<goto>";
		case 'r':	return "<return>";
		case 'b':	return "<bind>";
		case 's':	return "<state>";
		case 'c':	return "<call>";
		default:
			return "unknown";
	}
}

expr_t *
type_mismatch (expr_t *e1, expr_t *e2, int op)
{
	etype_t     t1, t2;

	t1 = extract_type (e1);
	t2 = extract_type (e2);

	return error (e1, "type mismatch: %s %s %s",
				  pr_type_name[t1], get_op_string (op), pr_type_name[t2]);
}

void
check_initialized (expr_t *e)
{
	if (options.warnings.uninited_variable) {
		if (e->type == ex_def
			&& !(e->e.def->type->type == ev_func
				 && e->e.def->global)
			&& !e->e.def->initialized) {
			warning (e, "%s may be used uninitialized", e->e.def->name);
			e->e.def->initialized = 1;	// only warn once
		}
	}
}

void
inc_users (expr_t *e)
{
	if (e && e->type == ex_temp)
		e->e.temp.users++;
	else if (e && e->type == ex_block)
		inc_users (e->e.block.result);
}

expr_t *
new_expr (void)
{
	expr_t     *e;

	ALLOC (16384, expr_t, exprs, e);

	e->line = pr_source_line;
	e->file = s_file;
	return e;
}

const char *
new_label_name (void)
{
	static int  label = 0;
	int         lnum = ++label;
	const char *fname = current_func->def->name;
	char       *lname;

	lname = nva ("$%s_%d", fname, lnum);
	SYS_CHECKMEM (lname);
	return lname;
}

expr_t *
new_error_expr (void)
{
	expr_t     *e = new_expr ();
	e->type = ex_error;
	return e;
}

expr_t *
new_label_expr (void)
{

	expr_t     *l = new_expr ();

	l->type = ex_label;
	l->e.label.name = new_label_name ();
	l->e.label.next = pr.labels;
	pr.labels = &l->e.label;
	return l;
}

expr_t *
new_block_expr (void)
{
	expr_t     *b = new_expr ();

	b->type = ex_block;
	b->e.block.head = 0;
	b->e.block.tail = &b->e.block.head;
	return b;
}

expr_t *
new_binary_expr (int op, expr_t *e1, expr_t *e2)
{
	expr_t     *e = new_expr ();

	if (e1->type == ex_error)
		return e1;
	if (e2 && e2->type == ex_error)
		return e2;

	inc_users (e1);
	inc_users (e2);

	e->type = ex_expr;
	e->e.expr.op = op;
	e->e.expr.e1 = e1;
	e->e.expr.e2 = e2;
	return e;
}

expr_t *
new_unary_expr (int op, expr_t *e1)
{
	expr_t     *e = new_expr ();

	if (e1 && e1->type == ex_error)
		return e1;

	inc_users (e1);

	e->type = ex_uexpr;
	e->e.expr.op = op;
	e->e.expr.e1 = e1;
	return e;
}

expr_t *
new_temp_def_expr (type_t *type)
{
	expr_t     *e = new_expr ();

	e->type = ex_temp;
	e->e.temp.type = type;
	return e;
}

expr_t *
new_bind_expr (expr_t *e1, expr_t *e2)
{
	expr_t     *e;

	if (!e2 || e2->type != ex_temp) {
		error (e1, "internal error");
		abort ();
	}
	e = new_expr ();
	e->type = ex_expr;
	e->e.expr.op = 'b';
	e->e.expr.e1 = e1;
	e->e.expr.e2 = e2;
	return e;
}

expr_t *
new_name_expr (const char *name)
{
	expr_t     *e = new_expr ();
	e->type = ex_name;
	e->e.string_val = name;
	return e;
}

expr_t *
new_def_expr (def_t *def)
{
	expr_t     *e = new_expr ();
	e->type = ex_def;
	e->e.def = def;
	return e;
}

expr_t *
new_self_expr (void)
{
	def_t      *def = get_def (&type_entity, ".self", pr.scope, st_global);

	def_initialized (def);
	return new_def_expr (def);
}

expr_t *
new_this_expr (void)
{
	type_t     *type = field_type (&type_id);
	def_t      *def = get_def (type, ".this", pr.scope, st_global);

	def_initialized (def);
	return new_def_expr (def);
}

expr_t *
append_expr (expr_t *block, expr_t *e)
{
	if (block->type != ex_block)
		abort ();

	if (!e || e->type == ex_error)
		return block;

	if (e->next) {
		error (e, "append_expr: expr loop detected");
		abort ();
	}

	*block->e.block.tail = e;
	block->e.block.tail = &e->next;

	return block;
}

void
print_expr (expr_t *e)
{
	printf (" ");
	if (!e) {
		printf ("(nil)");
		return;
	}
	switch (e->type) {
		case ex_error:
			printf ("(error)");
			break;
		case ex_label:
			printf ("%s", e->e.label.name);
			break;
		case ex_block:
			if (e->e.block.result) {
				print_expr (e->e.block.result);
				printf ("=");
			}
			printf ("{\n");
			for (e = e->e.block.head; e; e = e->next) {
				print_expr (e);
				puts ("");
			}
			printf ("}");
			break;
		case ex_expr:
			print_expr (e->e.expr.e1);
			if (e->e.expr.op == 'c') {
				expr_t     *p = e->e.expr.e2;

				printf ("(");
				while (p) {
					print_expr (p);
					if (p->next)
						printf (",");
					p = p->next;
				}
				printf (")");
			} else if (e->e.expr.op == 'b') {
				print_expr (e->e.expr.e1);
				printf ("<-->");
				print_expr (e->e.expr.e2);
			} else {
				print_expr (e->e.expr.e2);
				printf (" %s", get_op_string (e->e.expr.op));
			}
			break;
		case ex_uexpr:
			print_expr (e->e.expr.e1);
			printf (" u%s", get_op_string (e->e.expr.op));
			break;
		case ex_def:
			if (e->e.def->name)
				printf ("%s", e->e.def->name);
			if (!e->e.def->global) {
				printf ("<%d>", e->e.def->ofs);
			} else {
				printf ("[%d]", e->e.def->ofs);
			}
			break;
		case ex_temp:
			printf ("(");
			print_expr (e->e.temp.expr);
			printf (":");
			if (e->e.temp.def) {
				if (e->e.temp.def->name) {
					printf ("%s", e->e.temp.def->name);
				} else {
					printf ("<%d>", e->e.temp.def->ofs);
				}
			} else {
				printf ("<>");
			}
			printf (":%s:%d)@", pr_type_name[e->e.temp.type->type],
					e->e.temp.users);
			break;
		case ex_nil:
			printf ("NULL");
			break;
		case ex_string:
		case ex_name:
			printf ("\"%s\"", e->e.string_val);
			break;
		case ex_float:
			printf ("%g", e->e.float_val);
			break;
		case ex_vector:
			printf ("'%g", e->e.vector_val[0]);
			printf (" %g", e->e.vector_val[1]);
			printf (" %g'", e->e.vector_val[2]);
			break;
		case ex_quaternion:
			printf ("'%g", e->e.quaternion_val[0]);
			printf (" %g", e->e.quaternion_val[1]);
			printf (" %g", e->e.quaternion_val[2]);
			printf (" %g'", e->e.quaternion_val[3]);
			break;
		case ex_pointer:
			printf ("(%s)[%d]", pr_type_name[e->e.pointer.type->type],
					e->e.pointer.val);
			break;
		case ex_entity:
		case ex_field:
		case ex_func:
		case ex_integer:
			printf ("%d", e->e.integer_val);
			break;
		case ex_uinteger:
			printf ("%d", e->e.uinteger_val);
			break;
		case ex_short:
			printf ("%d", e->e.short_val);
			break;
	}
}

static expr_t *
do_op_string (int op, expr_t *e1, expr_t *e2)
{
	const char *s1, *s2;
	static dstring_t *temp_str;

	s1 = e1->e.string_val ? e1->e.string_val : "";
	s2 = e2->e.string_val ? e2->e.string_val : "";

	switch (op) {
		case '+':
			if (!temp_str)
				temp_str = dstring_newstr ();
			dstring_clearstr (temp_str);
			dstring_appendstr (temp_str, s1);
			dstring_appendstr (temp_str, s2);
			e1->e.string_val = save_string (temp_str->str);
			break;
		case LT:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) < 0;
			break;
		case GT:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) > 0;
			break;
		case LE:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) <= 0;
			break;
		case GE:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) >= 0;
			break;
		case EQ:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) == 0;
			break;
		case NE:
			e1->type = ex_integer;
			e1->e.integer_val = strcmp (s1, s2) != 0;
			break;
		default:
			return error (e1, "invalid operand for string");
	}
	return e1;
}

static expr_t *
do_op_float (int op, expr_t *e1, expr_t *e2)
{
	float       f1, f2;

	f1 = e1->e.float_val;
	f2 = e2->e.float_val;

	switch (op) {
		case '+':
			e1->e.float_val += f2;
			break;
		case '-':
			e1->e.float_val -= f2;
			break;
		case '*':
			e1->e.float_val *= f2;
			break;
		case '/':
			e1->e.float_val /= f2;
			break;
		case '&':
			e1->e.float_val = (int) f1 & (int) f2;
			break;
		case '|':
			e1->e.float_val = (int) f1 | (int) f2;
			break;
		case '^':
			e1->e.float_val = (int) f1 ^ (int) f2;
			break;
		case '%':
			e1->e.float_val = (int) f1 % (int) f2;
			break;
		case SHL:
			e1->e.float_val = (int) f1 << (int) f2;
			break;
		case SHR:
			e1->e.float_val = (int) f1 >> (int) f2;
			break;
		case AND:
			e1->type = ex_integer;
			e1->e.integer_val = f1 && f2;
			break;
		case OR:
			e1->type = ex_integer;
			e1->e.integer_val = f1 || f2;
			break;
		case LT:
			e1->type = ex_integer;
			e1->e.integer_val = f1 < f2;
			break;
		case GT:
			e1->type = ex_integer;
			e1->e.integer_val = f1 > f2;
			break;
		case LE:
			e1->type = ex_integer;
			e1->e.integer_val = f1 <= f2;
			break;
		case GE:
			e1->type = ex_integer;
			e1->e.integer_val = f1 >= f2;
			break;
		case EQ:
			e1->type = ex_integer;
			e1->e.integer_val = f1 == f2;
			break;
		case NE:
			e1->type = ex_integer;
			e1->e.integer_val = f1 != f2;
			break;
		default:
			return error (e1, "invalid operand for float");
	}
	return e1;
}

static expr_t *
do_op_vector (int op, expr_t *e1, expr_t *e2)
{
	float      *v1, *v2;

	v1 = e1->e.vector_val;
	v2 = e2->e.vector_val;

	switch (op) {
		case '+':
			VectorAdd (v1, v2, v1);
			break;
		case '-':
			VectorSubtract (v1, v2, v1);
			break;
		case '*':
			e1->type = ex_float;
			e1->e.float_val = DotProduct (v1, v2);
			break;
		case EQ:
			e1->type = ex_integer;
			e1->e.integer_val = (v1[0] == v2[0])
							 && (v1[1] == v2[1])
							 && (v1[2] == v2[2]);
			break;
		case NE:
			e1->type = ex_integer;
			e1->e.integer_val = (v1[0] == v2[0])
							 || (v1[1] != v2[1])
							 || (v1[2] != v2[2]);
			break;
		default:
			return error (e1, "invalid operand for vector");
	}
	return e1;
}

static expr_t *
do_op_integer (int op, expr_t *e1, expr_t *e2)
{
	int         i1, i2;

	i1 = e1->e.integer_val;
	i2 = e2->e.integer_val;

	switch (op) {
		case '+':
			e1->e.integer_val += i2;
			break;
		case '-':
			e1->e.integer_val -= i2;
			break;
		case '*':
			e1->e.integer_val *= i2;
			break;
		case '/':
			if (options.warnings.integer_divide)
				warning (e2, "%d / %d == %d", i1, i2, i1 / i2);
			e1->e.integer_val /= i2;
			break;
		case '&':
			e1->e.integer_val = i1 & i2;
			break;
		case '|':
			e1->e.integer_val = i1 | i2;
			break;
		case '^':
			e1->e.integer_val = i1 ^ i2;
			break;
		case '%':
			e1->e.integer_val = i1 % i2;
			break;
		case SHL:
			e1->e.integer_val = i1 << i2;
			break;
		case SHR:
			e1->e.integer_val = i1 >> i2;
			break;
		case AND:
			e1->e.integer_val = i1 && i2;
			break;
		case OR:
			e1->e.integer_val = i1 || i2;
			break;
		case LT:
			e1->type = ex_integer;
			e1->e.integer_val = i1 < i2;
			break;
		case GT:
			e1->type = ex_integer;
			e1->e.integer_val = i1 > i2;
			break;
		case LE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 <= i2;
			break;
		case GE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 >= i2;
			break;
		case EQ:
			e1->type = ex_integer;
			e1->e.integer_val = i1 == i2;
			break;
		case NE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 != i2;
			break;
		default:
			return error (e1, "invalid operand for integer");
	}
	return e1;
}

static expr_t *
do_op_uinteger (int op, expr_t *e1, expr_t *e2)
{
	unsigned int i1, i2;

	i1 = e1->e.uinteger_val;
	i2 = e2->e.uinteger_val;

	switch (op) {
		case '+':
			e1->e.uinteger_val += i2;
			break;
		case '-':
			e1->e.uinteger_val -= i2;
			break;
		case '*':
			e1->e.uinteger_val *= i2;
			break;
		case '/':
			if (options.warnings.integer_divide)
				warning (e2, "%d / %d == %d", i1, i2, i1 / i2);
			e1->e.uinteger_val /= i2;
			break;
		case '&':
			e1->e.uinteger_val = i1 & i2;
			break;
		case '|':
			e1->e.uinteger_val = i1 | i2;
			break;
		case '^':
			e1->e.uinteger_val = i1 ^ i2;
			break;
		case '%':
			e1->e.uinteger_val = i1 % i2;
			break;
		case SHL:
			e1->e.uinteger_val = i1 << i2;
			break;
		case SHR:
			e1->e.uinteger_val = i1 >> i2;
			break;
		case AND:
			e1->e.uinteger_val = i1 && i2;
			break;
		case OR:
			e1->e.uinteger_val = i1 || i2;
			break;
		case LT:
			e1->type = ex_integer;
			e1->e.integer_val = i1 < i2;
			break;
		case GT:
			e1->type = ex_integer;
			e1->e.integer_val = i1 > i2;
			break;
		case LE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 <= i2;
			break;
		case GE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 >= i2;
			break;
		case EQ:
			e1->type = ex_integer;
			e1->e.integer_val = i1 == i2;
			break;
		case NE:
			e1->type = ex_integer;
			e1->e.integer_val = i1 != i2;
			break;
		default:
			return error (e1, "invalid operand for uinteger");
	}
	return e1;
}

static expr_t *
do_op_huh (int op, expr_t *e1, expr_t *e2)
{
	return error (e1, "funny constant");
}

static expr_t *(*do_op[]) (int op, expr_t *e1, expr_t *e2) = {
	do_op_huh,							// ev_void
	do_op_string,						// ev_string
	do_op_float,						// ev_float
	do_op_vector,						// ev_vector
	do_op_huh,							// ev_entity
	do_op_huh,							// ev_field
	do_op_huh,							// ev_func
	do_op_huh,							// ev_pointer
	do_op_huh,							// ev_quaternion
	do_op_integer,						// ev_integer
	do_op_uinteger,						// ev_uinteger
	do_op_huh,							// ev_short
	do_op_huh,							// ev_struct
};

static expr_t *
binary_const (int op, expr_t *e1, expr_t *e2)
{
	etype_t     t1, t2;

	t1 = extract_type (e1);
	t2 = extract_type (e2);

	if (t1 == t2) {
		return do_op[t1] (op, e1, e2);
	} else {
		return type_mismatch (e1, e2, op);
	}
}

static expr_t *
field_expr (expr_t *e1, expr_t *e2)
{
	type_t     *t1, *t2;
	expr_t     *e;
	struct_field_t *field;
	class_t    *class;

	if (e1->type == ex_error)
		return e1;
	t1 = get_type (e1);
	switch (t1->type) {
		case ev_struct:
			if (e2->type != ex_name)
				return error (e2, "structure field name expected");
			field = struct_find_field (t1, e2->e.string_val);
			if (!field)
				return error (e2, "structure has no field %s",
							  e2->e.string_val);
			e2->type = ex_short;
			e2->e.short_val = field->offset;
			e = unary_expr ('.', address_expr (e1, e2, field->type));
			return e;
		case ev_pointer:
			switch (t1->aux_type->type) {
				case ev_struct:
					if (e2->type == ex_name) {
						field = struct_find_field (t1->aux_type,
												   e2->e.string_val);
						if (!field)
							return error (e2, "structure has no field %s",
										  e2->e.string_val);
						e2->type = ex_short;
						e2->e.short_val = field->offset;
						t1 = pointer_type (field->type);
					}
					break;
				case ev_object:
				case ev_class:
					if (e2->type == ex_name) {
						class = t1->aux_type->class;
						field = class_find_ivar (class, current_class != class,
												 e2->e.string_val);
						if (!field)
							return new_error_expr ();
						e2->type = ex_short;
						e2->e.short_val = field->offset;
						t1 = pointer_type (field->type);
					}
					break;
				default:
					break;
			}
			if (e1->type == ex_pointer) {
				if (e2->type == ex_short) {
					e1->e.pointer.val += e2->e.short_val;
				} else if (e2->type == ex_integer) {
					e1->e.pointer.val += e2->e.integer_val;
				} else if (e2->type == ex_uinteger) {
					e1->e.pointer.val += e2->e.uinteger_val;
				} else {
					break;
				}
				e1->e.pointer.type = t1->aux_type;
				return unary_expr ('.', e1);
			} else {
				e = new_binary_expr ('&', e1, e2);
				e->e.expr.type = t1;
				return unary_expr ('.', e);
			}
			break;
		case ev_entity:
			t2 = get_type (e2);
			if (e2->type == ex_error)
				return e2;
			if (t2->type == ev_field) {
				e = new_binary_expr ('.', e1, e2);
				e->e.expr.type = t2->aux_type;
				return e;
			}
			break;
		default:
			break;
	}
	return type_mismatch (e1, e2, '.');
}

expr_t *
test_expr (expr_t *e, int test)
{
	expr_t     *new = 0;
	etype_t     type;

	if (e->type == ex_error)
		return e;

	check_initialized (e);

	if (!test)
		return unary_expr ('!', e);

	type = extract_type (e);
	if (e->type == ex_error)
		return e;
	switch (type) {
		case ev_type_count:
			error (e, "internal error");
			abort ();
		case ev_void:
			return error (e, "void has no value");
		case ev_string:
			new = new_expr ();
			new->type = ex_string;
			break;
		case ev_uinteger:
		case ev_integer:
		case ev_short:
			return e;
		case ev_float:
			if (options.code.progsversion == PROG_ID_VERSION)
				return e;
			new = new_expr ();
			new->type = ex_float;
			break;
		case ev_vector:
			new = new_expr ();
			new->type = ex_vector;
			break;
		case ev_entity:
			new = new_expr ();
			new->type = ex_entity;
			break;
		case ev_field:
			new = new_expr ();
			new->type = ex_nil;
			break;
		case ev_func:
			new = new_expr ();
			new->type = ex_nil;
			break;
		case ev_pointer:
			new = new_expr ();
			new->type = ex_nil;
			break;
		case ev_quaternion:
			new = new_expr ();
			new->type = ex_quaternion;
			break;
		case ev_struct:
		case ev_object:
		case ev_class:
		case ev_sel:
		case ev_array:
			return error (e, "%s cannot be tested", pr_type_name[type]);
	}
	new->line = e->line;
	new->file = e->file;
	new = binary_expr (NE, e, new);
	new->line = e->line;
	new->file = e->file;
	return new;
}

void
convert_int (expr_t *e)
{
	e->type = ex_float;
	e->e.float_val = e->e.integer_val;
}

void
convert_nil (expr_t *e, type_t *t)
{
	e->type = expr_types[t->type];
	if (e->type == ex_pointer)
		e->e.pointer.type = &type_void;
}

expr_t *
binary_expr (int op, expr_t *e1, expr_t *e2)
{
	type_t     *t1, *t2;
	type_t     *type = 0;
	expr_t     *e;

	if (e1->type == ex_error)
		return e1;
	if (e2->type == ex_error)
		return e2;

	convert_name (e1);
	check_initialized (e1);

	if (e1->type == ex_block && e1->e.block.is_call
		&& e2->type == ex_block && e2->e.block.is_call && e1->e.block.result) {
		e = new_temp_def_expr (e1->e.block.result->e.def->type);
		inc_users (e);					// for the block itself
		e1 = assign_expr (e, e1);
	}

	if (op == '.')
		return field_expr (e1, e2);

	convert_name (e2);
	check_initialized (e2);

	if (op == OR || op == AND) {
		e1 = test_expr (e1, true);
		e2 = test_expr (e2, true);
	}

	if (e1->type == ex_error)
		return e1;
	if (e2->type == ex_error)
		return e2;
	t1 = get_type (e1);
	t2 = get_type (e2);
	if (!t1 || !t2) {
		error (e1, "internal error");
		abort ();
	}
	if (op == EQ || op == NE) {
		if (e1->type == ex_nil) {
			t1 = t2;
			convert_nil (e1, t1);
		} else if (e2->type == ex_nil) {
			t2 = t1;
			convert_nil (e2, t2);
		}
	}

	if (e1->type == ex_integer
		&& (t2 == &type_float
			|| t2 == &type_vector
			|| t2 == &type_quaternion)) {
		convert_int (e1);
		t1 = &type_float;
	} else if (e2->type == ex_integer
			   && (t1 == &type_float
				   || t1 == &type_vector
				   || t1 == &type_quaternion)) {
		convert_int (e2);
		t2 = &type_float;
	}

	if (e1->type >= ex_string && e2->type >= ex_string)
		return binary_const (op, e1, e2);

	if ((op == '&' || op == '|')
		&& e1->type == ex_uexpr && e1->e.expr.op == '!' && !e1->paren) {
		if (options.traditional) {
			notice (e1, "precedence of `!' and `%c' inverted for traditional "
					    "code", op);
			e1->e.expr.e1->paren = 1;
			return unary_expr ('!', binary_expr (op, e1->e.expr.e1, e2));
		} else {
			warning (e1, "ambiguous logic. Suggest explicit parentheses with "
					 "expressions involving ! and %c", op);
		}
	}

	if (t1 != t2) {
		switch (t1->type) {
			case ev_float:
				if (t2 == &type_vector && op == '*') {
					type = &type_vector;
				} else {
					goto type_mismatch;
				}
				break;
			case ev_vector:
				if (t2 == &type_float && op == '*') {
					type = &type_vector;
				} else {
					goto type_mismatch;
				}
				break;
			case ev_field:
				if (t1->aux_type == t2) {
					type = t1->aux_type;
				} else {
					goto type_mismatch;
				}
				break;
			case ev_func:
				if (e1->type == ex_func && !e1->e.func_val) {
					type = t2;
				} else if (e2->type == ex_func && !e2->e.func_val) {
					type = t1;
				} else {
					goto type_mismatch;
				}
				break;
			default:
			  type_mismatch:
				return type_mismatch (e1, e2, op);
		}
	} else {
		type = t1;
	}
	if ((op >= OR && op <= GT) || op == '>' || op == '<') {
		if (options.code.progsversion > PROG_ID_VERSION)
			type = &type_integer;
		else
			type = &type_float;
	} else if (op == '*' && t1 == &type_vector && t2 == &type_vector) {
		type = &type_float;
	}
	if (!type)
		error (e1, "internal error");

	e = new_binary_expr (op, e1, e2);
	e->e.expr.type = type;
	return e;
}

expr_t *
asx_expr (int op, expr_t *e1, expr_t *e2)
{
	if (e1->type == ex_error)
		return e1;
	else if (e2->type == ex_error)
		return e2;
	else {
		expr_t     *e = new_expr ();

		*e = *e1;
		return assign_expr (e, binary_expr (op, e1, e2));
	}
}

expr_t *
unary_expr (int op, expr_t *e)
{
	convert_name (e);
	check_initialized (e);
	if (e->type == ex_error)
		return e;
	switch (op) {
		case '-':
			switch (e->type) {
				case ex_error:
				case ex_label:
				case ex_name:
					error (e, "internal error");
					abort ();
				case ex_uexpr:
					if (e->e.expr.op == '-')
						return e->e.expr.e1;
				case ex_block:
					if (!e->e.block.result)
						return error (e, "invalid type for unary -");
				case ex_expr:
				case ex_def:
				case ex_temp:
					{
						expr_t     *n = new_unary_expr (op, e);

						n->e.expr.type = (e->type == ex_def)
							? e->e.def->type : e->e.expr.type;
						return n;
					}
				case ex_short:
					e->e.short_val *= -1;
					return e;
				case ex_integer:
				case ex_uinteger:
					e->e.integer_val *= -1;
					return e;
				case ex_float:
					e->e.float_val *= -1;
					return e;
				case ex_nil:
				case ex_string:
				case ex_entity:
				case ex_field:
				case ex_func:
				case ex_pointer:
					return error (e, "invalid type for unary -");
				case ex_vector:
					e->e.vector_val[0] *= -1;
					e->e.vector_val[1] *= -1;
					e->e.vector_val[2] *= -1;
					return e;
				case ex_quaternion:
					e->e.quaternion_val[0] *= -1;
					e->e.quaternion_val[1] *= -1;
					e->e.quaternion_val[2] *= -1;
					e->e.quaternion_val[3] *= -1;
					return e;
			}
			break;
		case '!':
			switch (e->type) {
				case ex_error:
				case ex_label:
				case ex_name:
					error (e, "internal error");
					abort ();
				case ex_block:
					if (!e->e.block.result)
						return error (e, "invalid type for unary !");
				case ex_uexpr:
				case ex_expr:
				case ex_def:
				case ex_temp:
					{
						expr_t     *n = new_unary_expr (op, e);

						if (options.code.progsversion > PROG_ID_VERSION)
							n->e.expr.type = &type_integer;
						else
							n->e.expr.type = &type_float;
						return n;
					}
				case ex_nil:
					return error (e, "invalid type for unary !");
				case ex_short:
					e->e.short_val = !e->e.short_val;
					return e;
				case ex_integer:
				case ex_uinteger:
					e->e.integer_val = !e->e.integer_val;
					return e;
				case ex_float:
					e->e.integer_val = !e->e.float_val;
					e->type = ex_integer;
					return e;
				case ex_string:
					e->e.integer_val = !e->e.string_val || !e->e.string_val[0];
					e->type = ex_integer;
					return e;
				case ex_vector:
					e->e.integer_val = !e->e.vector_val[0]
						&& !e->e.vector_val[1]
						&& !e->e.vector_val[2];
					e->type = ex_integer;
					return e;
				case ex_quaternion:
					e->e.integer_val = !e->e.quaternion_val[0]
						&& !e->e.quaternion_val[1]
						&& !e->e.quaternion_val[2]
						&& !e->e.quaternion_val[3];
					e->type = ex_integer;
					return e;
				case ex_entity:
				case ex_field:
				case ex_func:
				case ex_pointer:
					error (e, "internal error");
					abort ();
			}
			break;
		case '~':
			switch (e->type) {
				case ex_error:
				case ex_label:
				case ex_name:
					error (e, "internal error");
					abort ();
				case ex_uexpr:
					if (e->e.expr.op == '~')
						return e->e.expr.e1;
				case ex_block:
					if (!e->e.block.result)
						return error (e, "invalid type for unary ~");
				case ex_expr:
				case ex_def:
				case ex_temp:
					{
						expr_t     *n = new_unary_expr (op, e);
						type_t     *t = get_type (e);

						if (t != &type_integer && t != &type_float)
							return error (e, "invalid type for unary ~");
						n->e.expr.type = t;
						return n;
					}
				case ex_short:
					e->e.short_val = ~e->e.short_val;
					return e;
				case ex_integer:
				case ex_uinteger:
					e->e.integer_val = ~e->e.integer_val;
					return e;
				case ex_float:
					e->e.float_val = ~(int) e->e.float_val;
					e->type = ex_integer;
					return e;
				case ex_nil:
				case ex_string:
				case ex_vector:
				case ex_quaternion:
				case ex_entity:
				case ex_field:
				case ex_func:
				case ex_pointer:
					return error (e, "invalid type for unary ~");
			}
			break;
		case '.':
			if (extract_type (e) != ev_pointer)
				return error (e, "invalid type for unary .");
			e = new_unary_expr ('.', e);
			e->e.expr.type = get_type (e->e.expr.e1)->aux_type;
			return e;
	}
	error (e, "internal error");
	abort ();
}

int
has_function_call (expr_t *e)
{
	switch (e->type) {
		case ex_block:
			if (e->e.block.is_call)
				return 1;
			for (e = e->e.block.head; e; e = e->next)
				if (has_function_call (e))
					return 1;
			return 0;
		case ex_expr:
			if (e->e.expr.op == 'c')
				return 1;
			return (has_function_call (e->e.expr.e1)
					|| has_function_call (e->e.expr.e2));
		case ex_uexpr:
			if (e->e.expr.op != 'g')
				return has_function_call (e->e.expr.e1);
		default:
			return 0;
	}
}

expr_t *
function_expr (expr_t *e1, expr_t *e2)
{
	etype_t     t1;
	expr_t     *e;
	int         arg_count = 0, parm_count = 0;
	type_t     *ftype;
	int         i;
	expr_t     *args = 0, **a = &args;
	type_t     *arg_types[MAX_PARMS];
	expr_t     *arg_exprs[MAX_PARMS][2];
	int         arg_expr_count = 0;
	expr_t     *call;
	expr_t     *err = 0;

	if (e1->type == ex_error)
		return e1;
	for (e = e2; e; e = e->next)
		convert_name (e);
	for (e = e2; e; e = e->next) {
		if (e->type == ex_error)
			return e;
		arg_count++;
	}

	t1 = extract_type (e1);

	if (t1 != ev_func) {
		if (e1->type == ex_def)
			return error (e1, "Called object \"%s\" is not a function",
						  e1->e.def->name);
		else
			return error (e1, "Called object is not a function");
	}

	if (e1->type == ex_def && e2 && e2->type == ex_string) {
		// FIXME eww, I hate this, but it's needed :(
		// FIXME make a qc hook? :)
		def_t      *func = e1->e.def;
		def_t      *e = ReuseConstant (e2, 0);

		if (strncmp (func->name, "precache_sound", 14) == 0)
			PrecacheSound (e, func->name[4]);
		else if (strncmp (func->name, "precache_model", 14) == 0)
			PrecacheModel (e, func->name[14]);
		else if (strncmp (func->name, "precache_file", 13) == 0)
			PrecacheFile (e, func->name[13]);
	}

	ftype = e1->type == ex_def ? e1->e.def->type : e1->e.expr.type;

	if (arg_count > MAX_PARMS) {
		return error (e1, "more than %d parameters", MAX_PARMS);
	}
	if (ftype->num_parms < -1) {
		if (-arg_count > ftype->num_parms + 1) {
			if (!options.traditional)
				return error (e1, "too few arguments");
			warning (e1, "too few arguments");
		}
		parm_count = -ftype->num_parms - 1;
	} else if (ftype->num_parms >= 0) {
		if (arg_count > ftype->num_parms) {
			printf ("%d %d %s\n", arg_count, ftype->num_parms, e1->e.def->name);
			return error (e1, "too many arguments");
		} else if (arg_count < ftype->num_parms) {
			if (!options.traditional)
				return error (e1, "too few arguments");
			warning (e1, "too few arguments");
		}
		parm_count = ftype->num_parms;
	}
	for (i = arg_count - 1, e = e2; i >= 0; i--, e = e->next) {
		type_t     *t = get_type (e);

		if (ftype->parm_types[i] == &type_float && e->type == ex_integer) {
			e->type = ex_float;
			e->e.float_val = e->e.integer_val;
			t = &type_float;
		}
		if (i < parm_count) {
			if (t == &type_void) {
				t = ftype->parm_types[i];
				e->type = expr_types[t->type];
			}
			if (!type_assignable (ftype->parm_types[i], t)) {
				print_type (ftype->parm_types[i]); puts ("");
				print_type (t); puts ("");
				err = error (e, "type mismatch for parameter %d of %s",
							 i + 1, e1->e.def->name);
			}
		} else {
			if (e->type == ex_integer && options.warnings.vararg_integer)
				warning (e, "passing integer consant into ... function");
		}
		arg_types[arg_count - 1 - i] = t;
	}
	if (err)
		return err;

	call = new_block_expr ();
	call->e.block.is_call = 1;
	for (e = e2, i = 0; e; e = e->next, i++) {
		if (has_function_call (e)) {
			*a = new_temp_def_expr (arg_types[i]);
			arg_exprs[arg_expr_count][0] = e;
			arg_exprs[arg_expr_count][1] = *a;
			arg_expr_count++;
		} else {
			*a = e;
		}
		a = &(*a)->next;
	}
	for (i = 0; i < arg_expr_count - 1; i++) {
		append_expr (call, assign_expr (arg_exprs[i][1], arg_exprs[i][0]));
	}
	if (arg_expr_count) {
		e = new_bind_expr (arg_exprs[arg_expr_count - 1][0],
						   arg_exprs[arg_expr_count - 1][1]);
		inc_users (arg_exprs[arg_expr_count - 1][0]);
		inc_users (arg_exprs[arg_expr_count - 1][1]);
		append_expr (call, e);
	}
	e = new_binary_expr ('c', e1, args);
	e->e.expr.type = ftype->aux_type;
	append_expr (call, e);
	if (ftype->aux_type != &type_void) {
		expr_t     *ret = new_expr ();

		ret->type = ex_def;
		ret->e.def = new_def (ftype->aux_type, 0, pr.scope);
		ret->e.def->ofs = def_ret.ofs;

		call->e.block.result = ret;
	}
	return call;
}

expr_t *
return_expr (function_t *f, expr_t *e)
{
	if (!e) {
		if (f->def->type->aux_type != &type_void) {
			if (options.traditional) {
				warning (e, "return from non-void function without a value");
				e = new_expr ();
				e->type = ex_nil;
			} else {
				e = error (e, "return from non-void function without a value");
				return e;
			}
		}
	}
	if (e) {
		type_t     *t = get_type (e);

		if (e->type == ex_error)
			return e;
		if (f->def->type->aux_type == &type_void)
			return error (e, "returning a value for a void function");
		if (f->def->type->aux_type == &type_float && e->type == ex_integer) {
			e->type = ex_float;
			e->e.float_val = e->e.integer_val;
			t = &type_float;
		}
		if (t == &type_void) {
			t = f->def->type->aux_type;
			e->type = expr_types[t->type];
		}
		if (!type_assignable (f->def->type->aux_type, t))
			return error (e, "type mismatch for return value of %s",
						  f->def->name);
	}
	return new_unary_expr ('r', e);
}

expr_t *
conditional_expr (expr_t *cond, expr_t *e1, expr_t *e2)
{
	expr_t     *block = new_block_expr ();
	type_t     *type1 = get_type (e1);
	type_t     *type2 = get_type (e2);
	expr_t     *tlabel = new_label_expr ();
	expr_t     *elabel = new_label_expr ();

	if (cond->type == ex_error)
		return cond;
	if (e1->type == ex_error)
		return e1;
	if (e2->type == ex_error)
		return e2;

	block->e.block.result = (type1 == type2) ? new_temp_def_expr (type1) : 0;
	append_expr (block, new_binary_expr ('i', test_expr (cond, 1), tlabel));
	if (block->e.block.result)
		append_expr (block, assign_expr (block->e.block.result, e2));
	else
		append_expr (block, e2);
	append_expr (block, new_unary_expr ('g', elabel));
	append_expr (block, tlabel);
	if (block->e.block.result)
		append_expr (block, assign_expr (block->e.block.result, e1));
	else
		append_expr (block, e1);
	append_expr (block, elabel);
	return block;
}

expr_t *
incop_expr (int op, expr_t *e, int postop)
{
	expr_t     *one = new_expr ();
	expr_t     *incop;

	if (e->type == ex_error)
		return e;

	one->type = ex_integer;			// integer constants get auto-cast to float
	one->e.integer_val = 1;
	incop = asx_expr (op, e, one);
	if (postop) {
		expr_t     *temp;
		type_t     *type = get_type (e);
		expr_t     *block = new_block_expr ();

		temp = new_temp_def_expr (type);
		append_expr (block, assign_expr (temp, e));
		append_expr (block, incop);
		block->e.block.result = temp;
		return block;
	}
	return incop;
}

expr_t *
array_expr (expr_t *array, expr_t *index)
{
	type_t     *array_type = get_type (array);
	type_t     *index_type = get_type (index);
	expr_t     *scale;
	expr_t     *e;
	int         size;

	if (array->type == ex_error)
		return array;
	if (index->type == ex_error)
		return index;

	if (array_type->type != ev_pointer && array_type->type != ev_array)
		return error (array, "not an array");
	if (index_type != &type_integer && index_type != &type_uinteger)
		return error (index, "invalid array index type");
	if (array_type->num_parms
		&& index->type >= ex_integer
		&& index->e.uinteger_val >= array_type->num_parms)
			return error (index, "array index out of bounds");
	size = type_size (array_type->aux_type);
	if (size > 1) {
		scale = new_expr ();
		scale->type = expr_types[index_type->type];
		scale->e.integer_val = size;
		index = binary_expr ('*', index, scale);
	}
	if ((index->type == ex_integer
		 && index->e.integer_val < 32768 && index->e.integer_val >= -32768)
		|| (index->type == ex_uinteger
			&& index->e.uinteger_val < 32768)) {
		index->type = ex_short;
	}
	if (array_type->type == ev_array) {
		e = address_expr (array, index, array_type->aux_type);
	} else {
		e = new_binary_expr ('.', array, index);
		e->e.expr.type = pointer_type (array_type->aux_type);
	}
	e = unary_expr ('.', e);
	return e;
}

expr_t *
address_expr (expr_t *e1, expr_t *e2, type_t *t)
{
	expr_t     *e;
	type_t     *type = 0;

	if (e1->type == ex_error)
		return e1;

	if (!t)
		t = get_type (e1);

	switch (e1->type) {
		case ex_def:
			type = e1->e.def->type;
			if (type->type == ev_struct) {
				int         abs = e1->e.def->global;
				def_t      *def = e1->e.def;

				e = e1;
				e->type = ex_pointer;
				e->e.pointer.val = def->ofs;
				e->e.pointer.type = t;
				e->e.pointer.abs = abs;
			} else if (type->type == ev_array) {
				int         abs = e1->e.def->global;
				def_t      *def = e1->e.def;

				e = e1;
				e->type = ex_pointer;
				e->e.pointer.val = def->ofs;
				e->e.pointer.type = t;
				e->e.pointer.abs = abs;
			} else {
				e = new_unary_expr ('&', e1);
				e->e.expr.type = pointer_type (type);
			}
			break;
		case ex_expr:
			if (e1->e.expr.op == '.') {
				e = e1;
				e->e.expr.op = '&';
				e->e.expr.type = pointer_type (e->e.expr.type);
				break;
			}
			return error (e1, "invalid type for unary &");
		case ex_uexpr:
			if (e1->e.expr.op == '.') {
				e = e1->e.expr.e1;
				type = get_type (e)->aux_type;
				if (e->type == ex_expr && e->e.expr.op == '.') {
					e->e.expr.type = pointer_type (e->e.expr.type);
					e->e.expr.op = '&';
				}
				break;
			}
			return error (e1, "invalid type for unary &");
		default:
			return error (e1, "invalid type for unary &");
	}
	if (e2) {
		if (e2->type == ex_error)
			return e2;
		if (e->type == ex_pointer && e2->type == ex_short) {
			e->e.pointer.val += e2->e.short_val;
		} else {
			if (e2->type != ex_short || e2->e.short_val) {
				e = new_binary_expr ('&', e, e2);
			}
			if (e->type == ex_expr || e->type == ex_uexpr)
				e->e.expr.type = pointer_type (t);
		}
	}
	return e;
}

static inline int
is_indirect (expr_t *e)
{
	if (e->type == ex_expr && e->e.expr.op == '.')
		return 1;
	if (!(e->type == ex_uexpr && e->e.expr.op == '.'))
		return 0;
	e = e->e.expr.e1;
	if (e->type != ex_pointer
		|| !(e->e.pointer.val > 0 && e->e.pointer.val < 65536))
		return 1;
	return 0;
}

expr_t *
assign_expr (expr_t *e1, expr_t *e2)
{
	int         op = '=';
	type_t     *t1, *t2, *type;
	expr_t     *e;

	convert_name (e1);
	convert_name (e2);

	if (e1->type == ex_error)
		return e1;
	if (e2->type == ex_error)
		return e2;

	if (e1->type == ex_def)
		def_initialized (e1->e.def);
	//XXX func = func ???
	check_initialized (e2);
	t1 = get_type (e1);
	t2 = get_type (e2);
	if (!t1 || !t2) {
		error (e1, "internal error");
		abort ();
	}
	if (e2->type == ex_integer
		&& (t1 == &type_float
			|| t1 == &type_vector
			|| t1 == &type_quaternion)) {
		convert_int (e2);
		t2 = &type_float;
	}

	if (t1->type != ev_void && e2->type == ex_nil) {
		t2 = t1;
		convert_nil (e2, t2);
	}

	e2->rvalue = 1;

	if (!type_assignable (t1, t2)) {
		if (!options.traditional || t1->type != ev_func || t2->type != ev_func)
			return type_mismatch (e1, e2, op);
		warning (e1, "assignment between disparate function types");
	}
	type = t1;
	if (is_indirect (e1) && is_indirect (e2)) {
		expr_t     *temp = new_temp_def_expr (t1);

		e = new_block_expr ();
		append_expr (e, assign_expr (temp, e2));
		append_expr (e, assign_expr (e1, temp));
		e->e.block.result = temp;
		return e;
	} else if (is_indirect (e1)) {
		if (e1->type == ex_expr) {
			if (get_type (e1->e.expr.e1) == &type_entity) {
				type = e1->e.expr.type;
				e1->e.expr.type = pointer_type (type);
				e1->e.expr.op = '&';
			}
			op = PAS;
		} else {
			e = e1->e.expr.e1;
			if (e->type != ex_pointer
				|| !(e->e.pointer.val > 0 && e->e.pointer.val < 65536)) {
				e1 = e;
				op = PAS;
			}
		}
	} else if (is_indirect (e2)) {
		if (e2->type == ex_uexpr) {
			e = e2->e.expr.e1;
			if (e->type != ex_pointer
				|| !(e->e.pointer.val > 0 && e->e.pointer.val < 65536)) {
				if (e->type == ex_expr && e->e.expr.op == '&'
					&& e->e.expr.type->type == ev_pointer
					&& e->e.expr.e1->type < ex_string) {
					e2 = e;
					e2->e.expr.op = '.';
				}
			}
		}
	}
	if (!type)
		error (e1, "internal error");

	e = new_binary_expr (op, e1, e2);
	e->e.expr.type = type;
	return e;
}

expr_t *
cast_expr (type_t *type, expr_t *e)
{
	expr_t    *c;
	type_t    *e_type;

	convert_name (e);

	if (e->type == ex_error)
		return e;

	e_type = get_type (e);

	if (type->type == ev_pointer && e_type->type == ev_pointer) {
		c = new_unary_expr ('C', e);
		c->e.expr.type = type;
	} else if (((type == &type_integer || type == &type_uinteger)
				&& e_type == &type_float)
			   || (type == &type_float
				   && (e_type == &type_integer || e_type == &type_uinteger))) {
		c = new_unary_expr ('C', e);
		c->e.expr.type = type;
	} else {
		c = error (e, "can not cast from %s to %s",
				   pr_type_name[extract_type (e)], pr_type_name[type->type]);
	}
	return c;
}

void
init_elements (def_t *def, expr_t *eles)
{
	expr_t     *e;
	int         count, i;
	pr_type_t  *g = G_POINTER (pr_type_t, def->ofs);

	for (count = 0, e = eles->e.block.head; e; count++, e = e->next)
		if (e->type == ex_error)
			return;
	if (count > def->type->num_parms) {
		warning (eles, "excessive elements in initializer");
		count = def->type->num_parms;
	}
	for (i = 0, e = eles->e.block.head; i < count; i++, e = e->next) {
		if (e->type == ex_block) {
			warning (e, "not yet implemented");
		} else if (e->type >= ex_string) {
			if (get_type (e) != def->type->aux_type) {
				error (e, "type mismatch in initializer");
				g += type_size (def->type->aux_type);
			} else {
				if (e->type == ex_string) {
					g->string_var = ReuseString (e->e.string_val);
				} else {
					memcpy (g, &e->e, type_size (get_type (e)) * 4);
				}
				g += type_size (get_type (e));
			}
		} else {
			error (e, "non-constant initializer");
		}
	}
}

expr_t *
selector_expr (keywordarg_t *selector)
{
	dstring_t  *sel_id = dstring_newstr ();
	dstring_t  *sel_types = dstring_newstr ();
	expr_t     *sel;
	selector_name (sel_id, selector);
	selector_types (sel_types, selector);
	//printf ("'%s' '%s'\n", sel_id->str, sel_types->str);
	sel = new_def_expr (selector_def (sel_id->str, sel_types->str));
	dstring_delete (sel_id);
	dstring_delete (sel_types);
	return address_expr (sel, 0, 0);
}

expr_t *
protocol_expr (const char *protocol)
{
	return error (0, "not implemented");
}

expr_t *
encode_expr (type_t *type)
{
	dstring_t  *encoding = dstring_newstr ();
	expr_t     *e = new_expr ();

	encode_type (encoding, type);
	e->type = ex_string;
	e->e.string_val = encoding->str;
	free (encoding);
	return e;
}

expr_t *
message_expr (expr_t *receiver, keywordarg_t *message)
{
	expr_t     *args = 0, **a = &args;
	expr_t     *selector = selector_expr (message);
	expr_t     *call;
	keywordarg_t *m;
	int         super = 0;
	type_t     *rec_type;
	class_t    *class;
	method_t   *method;

	if (receiver->type == ex_name
		&& strcmp (receiver->e.string_val, "super") == 0) {
		super = 1;
		receiver->e.string_val = "self";
	}
	rec_type = get_type (receiver);

	if (receiver->type == ex_error)
		return receiver;

	if (rec_type->type != ev_pointer
		|| (rec_type->aux_type->type != ev_object
			&& rec_type->aux_type->type != ev_class))
		return error (receiver, "not a class/object");
	class = rec_type->aux_type->class;
	if (rec_type != &type_id) {
		method = class_message_response (class, selector);
		if (method)
			rec_type = method->type->aux_type;
	}
	for (m = message; m; m = m->next) {
		*a = m->expr;
		while ((*a))
			a = &(*a)->next;
	}
	*a = selector;
	a = &(*a)->next;
	*a = receiver;
	call = function_expr (send_message (super), args);

	if (call->type == ex_error)
		return receiver;

	call->e.block.result->e.def->type = rec_type;
	return call;
}