irio.c

/*
 * Copyright (C) 1995-2011 University of Karlsruhe.  All right reserved.
 *
 * This file is part of libFirm.
 *
 * This file may be distributed and/or modified under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation and appearing in the file LICENSE.GPL included in the
 * packaging of this file.
 *
 * Licensees holding valid libFirm Professional Edition licenses may use
 * this file in accordance with the libFirm Commercial License.
 * Agreement provided with the Software.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE.
 */

/**
 * @file
 * @brief   Write textual representation of firm to file.
 * @author  Moritz Kroll
 * @version $Id$
 */
#include "config.h"

#include <string.h>
#include <ctype.h>
#include <stdbool.h>
#include <stdarg.h>

#include "irio.h"

#include "irnode_t.h"
#include "irprog.h"
#include "irgraph_t.h"
#include "irprintf.h"
#include "ircons.h"
#include "irgmod.h"
#include "irflag_t.h"
#include "irgwalk.h"
#include "tv.h"
#include "array.h"
#include "error.h"
#include "typerep.h"
#include "adt/set.h"
#include "adt/obst.h"

#define SYMERROR ((unsigned) ~0)

typedef struct io_env_t
{
	int c;                /**< currently read char */
	FILE *file;
	set *idset;           /**< id_entry set, which maps from file ids to new Firm elements */
	int ignoreblocks;
	const char *inputname;
	int line;
	ir_type **fixedtypes;
	struct obstack obst;
	ir_graph *irg;
} io_env_t;

typedef enum typetag_t
{
	tt_align,
	tt_allocation,
	tt_builtin,
	tt_cond_jmp_predicate,
	tt_initializer,
	tt_iro,
	tt_keyword,
	tt_mode_arithmetic,
	tt_pin_state,
	tt_tpo,
	tt_type_state,
	tt_volatility,
	tt_linkage,
	tt_segment,
	tt_visibility
} typetag_t;

typedef enum keyword_t
{
	kw_constirg,
	kw_entity,
	kw_irg,
	kw_int_mode,
	kw_reference_mode,
	kw_float_mode,
	kw_modes,
	kw_type,
	kw_typegraph,
	kw_program,
	kw_segment_type
} keyword_t;

typedef struct symbol_t
{
	const char *str;      /**< The name of this symbol. */
	typetag_t   typetag;  /**< The type tag of this symbol. */
	unsigned    code;     /**< The value of this symbol. */
} symbol_t;

typedef struct id_entry
{
	long id;
	void *elem;
} id_entry;

/** The symbol table, a set of symbol_t elements. */
static set *symtbl;

/**
 * Compare two symbol table entries.
 */
static int symbol_cmp(const void *elt, const void *key, size_t size)
{
	int res;
	const symbol_t *entry = (const symbol_t *) elt;
	const symbol_t *keyentry = (const symbol_t *) key;
	(void) size;
	res = entry->typetag - keyentry->typetag;
	if (res) return res;
	return strcmp(entry->str, keyentry->str);
}

static int id_cmp(const void *elt, const void *key, size_t size)
{
	const id_entry *entry = (const id_entry *) elt;
	const id_entry *keyentry = (const id_entry *) key;
	(void) size;
	return entry->id - keyentry->id;
}

static void __attribute__((format(printf, 2, 3)))
parse_error(io_env_t *env, const char *fmt, ...)
{
	va_list ap;
	int     line = env->line;

	/* workaround read_c "feature" that a '\n' triggers the line++
	 * instead of the character after the '\n' */
	if (env->c == '\n') {
		line--;
	}

	fprintf(stderr, "%s:%d: error ", env->inputname, line);

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
}

/** Initializes the symbol table. May be called more than once without problems. */
static void symtbl_init(void)
{
	symbol_t key;

	/* Only initialize once */
	if (symtbl != NULL)
		return;

	symtbl = new_set(symbol_cmp, 256);

#define INSERT(tt, s, cod)                                       \
	key.str = (s);                                               \
	key.typetag = (tt);                                          \
	key.code = (cod);                                            \
	set_insert(symtbl, &key, sizeof(key), firm_fnv_hash_str(s) + tt * 17)

#define INSERTENUM(tt, e) INSERT(tt, #e, e)
#define INSERTKEYWORD(k) INSERT(tt_keyword, #k, kw_##k)

	INSERT(tt_tpo, "array", tpo_array);
	INSERT(tt_tpo, "class", tpo_class);
	INSERT(tt_tpo, "method", tpo_method);
	INSERT(tt_tpo, "pointer", tpo_pointer);
	INSERT(tt_tpo, "primitive", tpo_primitive);
	INSERT(tt_tpo, "struct", tpo_struct);
	INSERT(tt_tpo, "union", tpo_union);
	INSERT(tt_tpo, "Unknown", tpo_unknown);

	INSERT(tt_segment, "global", IR_SEGMENT_GLOBAL);
	INSERT(tt_segment, "thread_local", IR_SEGMENT_THREAD_LOCAL);
	INSERT(tt_segment, "constructors", IR_SEGMENT_CONSTRUCTORS);
	INSERT(tt_segment, "destructors", IR_SEGMENT_DESTRUCTORS);

	INSERT(tt_linkage, "constant", IR_LINKAGE_CONSTANT);
	INSERT(tt_linkage, "weak", IR_LINKAGE_WEAK);
	INSERT(tt_linkage, "garbage_collect", IR_LINKAGE_GARBAGE_COLLECT);
	INSERT(tt_linkage, "merge", IR_LINKAGE_MERGE);
	INSERT(tt_linkage, "hidden_user", IR_LINKAGE_HIDDEN_USER);

	INSERT(tt_visibility, "local", ir_visibility_local);
	INSERT(tt_visibility, "external", ir_visibility_external);
	INSERT(tt_visibility, "default", ir_visibility_default);
	INSERT(tt_visibility, "private", ir_visibility_private);

	INSERTKEYWORD(constirg);
	INSERTKEYWORD(entity);
	INSERTKEYWORD(irg);
	INSERTKEYWORD(int_mode);
	INSERTKEYWORD(float_mode);
	INSERTKEYWORD(reference_mode);
	INSERTKEYWORD(modes);
	INSERTKEYWORD(type);
	INSERTKEYWORD(typegraph);
	INSERTKEYWORD(program);
	INSERTKEYWORD(segment_type);

#include "gen_irio_lex.inl"

	INSERTENUM(tt_align, align_non_aligned);
	INSERTENUM(tt_align, align_is_aligned);

	INSERTENUM(tt_builtin, ir_bk_trap);
	INSERTENUM(tt_builtin, ir_bk_debugbreak);
	INSERTENUM(tt_builtin, ir_bk_return_address);
	INSERTENUM(tt_builtin, ir_bk_frame_address);
	INSERTENUM(tt_builtin, ir_bk_prefetch);
	INSERTENUM(tt_builtin, ir_bk_ffs);
	INSERTENUM(tt_builtin, ir_bk_clz);
	INSERTENUM(tt_builtin, ir_bk_ctz);
	INSERTENUM(tt_builtin, ir_bk_popcount);
	INSERTENUM(tt_builtin, ir_bk_parity);
	INSERTENUM(tt_builtin, ir_bk_bswap);
	INSERTENUM(tt_builtin, ir_bk_inport);
	INSERTENUM(tt_builtin, ir_bk_outport);
	INSERTENUM(tt_builtin, ir_bk_inner_trampoline);

	INSERTENUM(tt_cond_jmp_predicate, COND_JMP_PRED_NONE);
	INSERTENUM(tt_cond_jmp_predicate, COND_JMP_PRED_TRUE);
	INSERTENUM(tt_cond_jmp_predicate, COND_JMP_PRED_FALSE);

	INSERTENUM(tt_initializer, IR_INITIALIZER_CONST);
	INSERTENUM(tt_initializer, IR_INITIALIZER_TARVAL);
	INSERTENUM(tt_initializer, IR_INITIALIZER_NULL);
	INSERTENUM(tt_initializer, IR_INITIALIZER_COMPOUND);

	INSERTENUM(tt_mode_arithmetic, irma_uninitialized);
	INSERTENUM(tt_mode_arithmetic, irma_none);
	INSERTENUM(tt_mode_arithmetic, irma_twos_complement);
	INSERTENUM(tt_mode_arithmetic, irma_ieee754);

	INSERTENUM(tt_pin_state, op_pin_state_floats);
	INSERTENUM(tt_pin_state, op_pin_state_pinned);
	INSERTENUM(tt_pin_state, op_pin_state_exc_pinned);
	INSERTENUM(tt_pin_state, op_pin_state_mem_pinned);

	INSERTENUM(tt_type_state, layout_undefined);
	INSERTENUM(tt_type_state, layout_fixed);

	INSERTENUM(tt_volatility, volatility_non_volatile);
	INSERTENUM(tt_volatility, volatility_is_volatile);

#undef INSERTKEYWORD
#undef INSERTENUM
#undef INSERT
}

static const char *get_segment_name(ir_segment_t segment)
{
	switch (segment) {
	case IR_SEGMENT_GLOBAL:       return "global";
	case IR_SEGMENT_THREAD_LOCAL: return "thread_local";
	case IR_SEGMENT_CONSTRUCTORS: return "constructors";
	case IR_SEGMENT_DESTRUCTORS:  return "destructors";
	}
	return "INVALID_SEGMENT";
}

static const char *get_visibility_name(ir_visibility visibility)
{
	switch (visibility) {
	case ir_visibility_local:    return "local";
	case ir_visibility_external: return "external";
	case ir_visibility_default:  return "default";
	case ir_visibility_private:  return "private";
	}
	return "INVALID_VISIBILITY";
}

/** Returns the according symbol value for the given string and tag, or SYMERROR if none was found. */
static unsigned symbol(const char *str, typetag_t typetag)
{
	symbol_t key, *entry;

	key.str = str;
	key.typetag = typetag;

	entry = (symbol_t*)set_find(symtbl, &key, sizeof(key), firm_fnv_hash_str(str) + typetag * 17);
	return entry ? entry->code : SYMERROR;
}

static void *get_id(io_env_t *env, long id)
{
	id_entry key, *entry;
	key.id = id;

	entry = (id_entry*)set_find(env->idset, &key, sizeof(key), (unsigned) id);
	return entry ? entry->elem : NULL;
}

static void set_id(io_env_t *env, long id, void *elem)
{
	id_entry key;
	key.id = id;
	key.elem = elem;
	set_insert(env->idset, &key, sizeof(key), (unsigned) id);
}

static void write_long(io_env_t *env, long value)
{
	fprintf(env->file, "%ld ", value);
}

static void write_int(io_env_t *env, int value)
{
	fprintf(env->file, "%d ", value);
}

static void write_unsigned(io_env_t *env, unsigned value)
{
	fprintf(env->file, "%u ", value);
}

static void write_entity_ref(io_env_t *env, ir_entity *entity)
{
	write_long(env, get_entity_nr(entity));
}

static void write_type_ref(io_env_t *env, ir_type *type)
{
	write_long(env, get_type_nr(type));
}

static void write_string(io_env_t *env, const char *string)
{
	const char *c;
	fputc('"', env->file);
	for (c = string; *c != '\0'; ++c) {
		switch (*c) {
		case '\n':
			fputc('\\', env->file);
			fputc('n', env->file);
			break;
		case '"':
		case '\\':
			fputc('\\', env->file);
			/* FALLTHROUGH */
		default:
			fputc(*c, env->file);
			break;
		}
	}
	fputc('"', env->file);
}

static void write_ident(io_env_t *env, ident *id)
{
	write_string(env, get_id_str(id));
	fputc(' ', env->file);
}

static void write_ident_null(io_env_t *env, ident *id)
{
	if (id == NULL) {
		fputs("NULL ", env->file);
	} else {
		write_ident(env, id);
	}
}

static void write_mode(io_env_t *env, ir_mode *mode)
{
	write_string(env, get_mode_name(mode));
	fputc(' ', env->file);
}

static void write_tarval(io_env_t *env, ir_tarval *tv)
{
	char buf[1024];
	write_mode(env, get_tarval_mode(tv));
	tarval_snprintf(buf, sizeof(buf), tv);
	fputs(buf, env->file);
	fputc(' ', env->file);
}

static void write_align(io_env_t *env, ir_align align)
{
	fputs(get_align_name(align), env->file);
	fputc(' ', env->file);
}

static void write_builtin_kind(io_env_t *env, ir_node *irn)
{
	fputs(get_builtin_kind_name(get_Builtin_kind(irn)), env->file);
	fputc(' ', env->file);
}

static void write_cond_jmp_predicate(io_env_t *env, ir_node *irn)
{
	fputs(get_cond_jmp_predicate_name(get_Cond_jmp_pred(irn)), env->file);
	fputc(' ', env->file);
}

static void write_list_begin(io_env_t *env)
{
	fputs("[", env->file);
}

static void write_list_end(io_env_t *env)
{
	fputs("] ", env->file);
}

static void write_initializer(io_env_t *env, ir_initializer_t *ini)
{
	FILE *f = env->file;
	ir_initializer_kind_t ini_kind = get_initializer_kind(ini);

	fputs(get_initializer_kind_name(ini_kind), f);
	fputc(' ', f);

	switch (ini_kind) {
	case IR_INITIALIZER_CONST:
		write_long(env, get_irn_node_nr(get_initializer_const_value(ini)));
		break;

	case IR_INITIALIZER_TARVAL:
		write_tarval(env, get_initializer_tarval_value(ini));
		break;

	case IR_INITIALIZER_NULL:
		break;

	case IR_INITIALIZER_COMPOUND: {
		size_t i, n = get_initializer_compound_n_entries(ini);
		ir_fprintf(f, "%zu ", n);
		for (i = 0; i < n; ++i)
			write_initializer(env, get_initializer_compound_value(ini, i));
		break;
	}

	default:
		panic("Unknown initializer kind");
	}
}

static void write_pin_state(io_env_t *env, ir_node *irn)
{
	fputs(get_op_pin_state_name(get_irn_pinned(irn)), env->file);
	fputc(' ', env->file);
}

static void write_volatility(io_env_t *env, ir_volatility vol)
{
	fputs(get_volatility_name(vol), env->file);
	fputc(' ', env->file);
}

static void export_type_common(io_env_t *env, ir_type *tp)
{
	fprintf(env->file, "\ttype %ld %s %u %u %s %u ",
	        get_type_nr(tp),
	        get_type_tpop_name(tp),
	        get_type_size_bytes(tp),
	        get_type_alignment_bytes(tp),
	        get_type_state_name(get_type_state(tp)),
	        tp->flags);
}

static void export_type_pre(io_env_t *env, ir_type *tp)
{
	FILE *f = env->file;

	/* skip types to be handled by post walker */
	switch (get_type_tpop_code(tp)) {
	case tpo_array:
	case tpo_method:
	case tpo_pointer:
		return;
	default:
		break;
	}

	export_type_common(env, tp);

	switch (get_type_tpop_code(tp)) {
	case tpo_uninitialized:
		panic("invalid type found");

	case tpo_class:
		write_ident_null(env, get_compound_ident(tp));
		break;

	case tpo_primitive:
		write_mode(env, get_type_mode(tp));
		break;

	case tpo_union:
	case tpo_struct:
	case tpo_enumeration:
		write_ident_null(env, get_compound_ident(tp));
		break;

	case tpo_array:
	case tpo_method:
	case tpo_pointer:
	case tpo_code:
	case tpo_none:
	case tpo_unknown:
		break;
	}
	fputc('\n', f);
}

static void export_type_post(io_env_t *env, ir_type *tp)
{
	FILE *f = env->file;
	size_t i;

	/* skip types already handled by pre walker */
	switch (get_type_tpop_code(tp)) {
	case tpo_class:
	case tpo_primitive:
	case tpo_struct:
	case tpo_union:
	case tpo_unknown:
	case tpo_uninitialized:
	case tpo_code:
	case tpo_none:
		return;
	case tpo_array:
	case tpo_method:
	case tpo_pointer:
	case tpo_enumeration:
		break;
	}

	export_type_common(env, tp);

	switch (get_type_tpop_code(tp)) {
	case tpo_array: {
		size_t n = get_array_n_dimensions(tp);
		ir_fprintf(f, "%zu %ld ", n, get_type_nr(get_array_element_type(tp)));
		for (i = 0; i < n; i++) {
			ir_node *lower = get_array_lower_bound(tp, i);
			ir_node *upper = get_array_upper_bound(tp, i);

			if (is_Const(lower))
				write_long(env, get_tarval_long(get_Const_tarval(lower)));
			else
				panic("Lower array bound is not constant");

			if (is_Const(upper))
				write_long(env, get_tarval_long(get_Const_tarval(upper)));
			else if (is_Unknown(upper))
				fputs("unknown ", f);
			else
				panic("Upper array bound is not constant");
		}
		break;
	}

	case tpo_method: {
		size_t nparams  = get_method_n_params(tp);
		size_t nresults = get_method_n_ress(tp);
		ir_fprintf(f, "%u %u %zu %zu ", get_method_calling_convention(tp),
			get_method_additional_properties(tp), nparams, nresults);
		for (i = 0; i < nparams; i++)
			write_long(env, get_type_nr(get_method_param_type(tp, i)));
		for (i = 0; i < nresults; i++)
			write_long(env, get_type_nr(get_method_res_type(tp, i)));
		ir_fprintf(f, "%u ", get_method_variadicity(tp));
		break;
	}

	case tpo_pointer:
		write_mode(env, get_type_mode(tp));
		write_long(env, get_type_nr(get_pointer_points_to_type(tp)));
		break;

	case tpo_enumeration:
		fprintf(stderr, "Enumeration type not handled yet by exporter\n");
		break;

	default:
		printf("export_type: Unknown type code \"%s\".\n",
		       get_type_tpop_name(tp));
		break;
	}
	fputc('\n', f);
}

static void export_entity(io_env_t *env, ir_entity *ent)
{
	FILE          *file       = env->file;
	ir_type       *owner      = get_entity_owner(ent);
	ir_visibility  visibility = get_entity_visibility(ent);
	ir_linkage     linkage    = get_entity_linkage(ent);

	/* we don't dump array_element_ent entities. They're a strange concept
	 * and lead to cycles in type_graph.
	 */
	if (is_Array_type(owner))
		return;

	fprintf(env->file, "\tentity ");
	write_long(env, get_entity_nr(ent));
	write_ident_null(env, get_entity_ident(ent));
	if (!entity_has_ld_ident(ent)) {
		write_ident_null(env, NULL);
	} else {
		write_ident_null(env, get_entity_ld_ident(ent));
	}

	/* visibility + linkage */
	if (visibility != ir_visibility_default) {
		fprintf(file, "%s ", get_visibility_name(visibility));
	}
	if (linkage & IR_LINKAGE_CONSTANT)
		fputs("constant ", file);
	if (linkage & IR_LINKAGE_WEAK)
		fputs("weak ", file);
	if (linkage & IR_LINKAGE_GARBAGE_COLLECT)
		fputs("garbage_collect ", file);
	if (linkage & IR_LINKAGE_MERGE)
		fputs("merge ", file);
	if (linkage & IR_LINKAGE_HIDDEN_USER)
		fputs("hidden_user ", file);

	fprintf(file, "%ld %ld %d %u %d %s ",
			get_type_nr(get_entity_type(ent)),
			get_type_nr(owner),
			get_entity_offset(ent),
			(unsigned) get_entity_offset_bits_remainder(ent),
			is_entity_compiler_generated(ent),
			get_volatility_name(get_entity_volatility(ent)));

	if (ent->initializer != NULL) {
		fputs("initializer ", env->file);
		write_initializer(env, get_entity_initializer(ent));
	} else if (entity_has_compound_ent_values(ent)) {
		size_t i, n = get_compound_ent_n_values(ent);
		fputs("compoundgraph ", env->file);
		ir_fprintf(env->file, "%zu ", n);
		for (i = 0; i < n; i++) {
			ir_entity *member = get_compound_ent_value_member(ent, i);
			ir_node   *irn    = get_compound_ent_value(ent, i);
			fprintf(env->file, "%ld %ld ", get_entity_nr(member), get_irn_node_nr(irn));
		}
	} else {
		fputs("none", env->file);
	}

	fputc('\n', env->file);
}

static void export_type_or_ent_pre(type_or_ent tore, void *ctx)
{
	io_env_t *env = (io_env_t *) ctx;
	if (get_kind(tore.typ) == k_type)
		export_type_pre(env, tore.typ);
}

static void export_type_or_ent_post(type_or_ent tore, void *ctx)
{
	io_env_t *env = (io_env_t *) ctx;

	switch (get_kind(tore.ent)) {
	case k_entity:
		export_entity(env, tore.ent);
		break;

	case k_type:
		export_type_post(env, tore.typ);
		break;

	default:
		panic("export_type_or_ent_post: Unknown type or entity.");
	}
}

static void export_ASM(io_env_t *env, ir_node *node)
{
	ir_asm_constraint *input_constraints    = get_ASM_input_constraints(node);
	ir_asm_constraint *output_constraints   = get_ASM_output_constraints(node);
	ident            **clobbers             = get_ASM_clobbers(node);
	int                n_input_constraints  = get_ASM_n_input_constraints(node);
	int                n_output_constraints = get_ASM_n_output_constraints(node);
	int                n_clobbers           = get_ASM_n_clobbers(node);
	int i;

	write_ident(env, get_ASM_text(node));
	write_list_begin(env);
	for (i = 0; i < n_input_constraints; ++i) {
		const ir_asm_constraint *constraint = &input_constraints[i];
		write_unsigned(env, constraint->pos);
		write_ident(env, constraint->constraint);
		write_mode(env, constraint->mode);
	}
	write_list_end(env);

	write_list_begin(env);
	for (i = 0; i < n_output_constraints; ++i) {
		const ir_asm_constraint *constraint = &output_constraints[i];
		write_unsigned(env, constraint->pos);
		write_ident(env, constraint->constraint);
		write_mode(env, constraint->mode);
	}
	write_list_end(env);

	write_list_begin(env);
	for (i = 0; i < n_clobbers; ++i) {
		ident *clobber = clobbers[i];
		write_ident(env, clobber);
	}
	write_list_end(env);
}

/**
 * Walker: exports every node.
 */
static void export_node(ir_node *irn, void *ctx)
{
	io_env_t *env = (io_env_t *) ctx;
	int i, n;
	unsigned opcode = get_irn_opcode(irn);

	if (env->ignoreblocks && opcode == iro_Block)
		return;

	fprintf(env->file, "\t%s ", get_irn_opname(irn));
	write_long(env, get_irn_node_nr(irn));

	write_list_begin(env);
	n = get_irn_arity(irn);
	if (!is_Block(irn)) {
		ir_node *block = get_nodes_block(irn);
		write_long(env, get_irn_node_nr(block));
	}

	for (i = 0; i < n; i++) {
		ir_node *pred = get_irn_n(irn, i);
		if (pred == NULL) {
			/* Anchor node may have NULL predecessors */
			assert(is_Anchor(irn));
			fputs("-1 ", env->file);
		} else {
			write_long(env, get_irn_node_nr(pred));
		}
	}
	write_list_end(env);

	fputs("{ ", env->file);

	switch (opcode) {
	case iro_Start:
	case iro_End:
	case iro_Block:
	case iro_Anchor:
		break;
	case iro_SymConst:
		/* TODO: only symconst_addr_ent implemented yet */
		assert(get_SymConst_kind(irn) == symconst_addr_ent);
		fprintf(env->file, "%ld ", get_entity_nr(get_SymConst_entity(irn)));
		write_mode(env, get_irn_mode(irn));
		break;
	case iro_Proj:
		write_mode(env, get_irn_mode(irn));
		fprintf(env->file, "%ld ", get_Proj_proj(irn));
		break;
	case iro_ASM:
		export_ASM(env, irn);
		break;
#include "gen_irio_export.inl"
	default:
		panic("no export code for node %+F\n", irn);
	}
	fputs("}\n", env->file);
}

static void export_modes(io_env_t *env)
{
	size_t i, n_modes = get_irp_n_modes();

	fputs("modes {\n", env->file);

	for (i = 0; i < n_modes; i++) {
		ir_mode *mode = get_irp_mode(i);

		if (mode_is_int(mode)) {
			fprintf(env->file, "\tint_mode ");
			write_string(env, get_mode_name(mode));
			fprintf(env->file, "%s %u %d %u ",
			        get_mode_arithmetic_name(get_mode_arithmetic(mode)),
			        get_mode_size_bits(mode), get_mode_sign(mode),
			        get_mode_modulo_shift(mode));
		} else if (mode_is_reference(mode)) {
			fprintf(env->file, "\treference_mode ");
			write_string(env, get_mode_name(mode));
			fprintf(env->file, "%s %u %u ",
					get_mode_arithmetic_name(get_mode_arithmetic(mode)),
					get_mode_size_bits(mode),
					get_mode_modulo_shift(mode));
			write_mode(env, get_reference_mode_signed_eq(mode));
			write_mode(env, get_reference_mode_unsigned_eq(mode));
			write_int(env, (mode == mode_P ? 1 : 0));
		} else if (mode_is_float(mode)) {
			fprintf(env->file, "\tfloat_mode ");
			write_string(env, get_mode_name(mode));
			fprintf(env->file, "%s %u %u ",
			        get_mode_arithmetic_name(get_mode_arithmetic(mode)),
			        get_mode_exponent_size(mode),
			        get_mode_mantissa_size(mode));
		} else {
			/* skip "internal" modes */
		}
		fputc('\n', env->file);
	}

	fputs("}\n", env->file);
}

static void export_program(io_env_t *env)
{
	FILE         *f = env->file;
	ir_segment_t  s;

	fputs("\nprogram {\n", f);
	if (irp_prog_name_is_set()) {
		fprintf(f, "\tname ");
		write_string(env, get_irp_name());
		fputc('\n', f);
	}

	for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
		ir_type *segment_type = get_segment_type(s);
		fprintf(f, "\tsegment_type %s ", get_segment_name(s));
		if (segment_type == NULL) {
			fputs(" NULL\n", f);
		} else {
			write_long(env, get_type_nr(segment_type));
			fputc('\n', f);
		}
	}
	fputs("}\n", f);
}

void ir_export(const char *filename)
{
	FILE *file = fopen(filename, "wt");
	if (file == NULL) {
		perror(filename);
		return;
	}

	ir_export_file(file, filename);
	fclose(file);
}

/* Exports the whole irp to the given file in a textual form. */
void ir_export_file(FILE *file, const char *outputname)
{
	io_env_t env;
	size_t i, n_irgs = get_irp_n_irgs();

	(void) outputname;
	env.file = file;

	export_modes(&env);

	fputs("\ntypegraph {\n", env.file);
	type_walk_prog(export_type_or_ent_pre, export_type_or_ent_post, &env);
	fputs("}\n", env.file);

	for (i = 0; i < n_irgs; i++) {
		ir_graph *irg       = get_irp_irg(i);

		fprintf(env.file, "\nirg %ld %ld {\n",
		        get_entity_nr(get_irg_entity(irg)),
		        get_type_nr(get_irg_frame_type(irg)));

		env.ignoreblocks = 0;
		irg_block_walk_graph(irg, NULL, export_node, &env);

		env.ignoreblocks = 1;
		irg_walk_anchors(irg, NULL, export_node, &env);

		fputs("}\n", env.file);
	}

	fprintf(env.file, "\nconstirg %ld {\n", get_irn_node_nr(get_const_code_irg()->current_block));

	walk_const_code(NULL, export_node, &env);
	fputs("}\n", env.file);

	export_program(&env);
}

/* Exports the given irg to the given file. */
void ir_export_irg(ir_graph *irg, FILE *file, const char *outputname)
{
	io_env_t env;

	(void) outputname;
	env.file = file;

	export_modes(&env);

	fputs("typegraph {\n", env.file);

	type_walk_irg(irg, export_type_or_ent_pre, export_type_or_ent_post, &env);

	fprintf(env.file, "}\n\nirg %ld {\n", get_entity_nr(get_irg_entity(irg)));

	env.ignoreblocks = 0;
	irg_block_walk_graph(irg, NULL, export_node, &env);

	env.ignoreblocks = 1;
	irg_walk_anchors(irg, NULL, export_node, &env);

	/* TODO: Only output needed constants */
	fprintf(env.file, "}\n\nconstirg %ld {\n", get_irn_node_nr(get_const_code_irg()->current_block));
	walk_const_code(NULL, export_node, &env);
	fputs("}\n", env.file);
}

static void read_c(io_env_t *env)
{
	int c = fgetc(env->file);
	env->c = c;
	if (c == '\n')
		env->line++;
}

/** Returns the first non-whitespace character or EOF. **/
static void skip_ws(io_env_t *env)
{
	while (true) {
		switch (env->c) {
		case ' ':
		case '\t':
		case '\n':
		case '\r':
			read_c(env);
			continue;

		default:
			return;
		}
	}
}

static void skip_to(io_env_t *env, char to_ch)
{
	while (env->c != to_ch && env->c != EOF) {
		read_c(env);
	}
}

static int expect_char(io_env_t *env, char ch)
{
	skip_ws(env);
	if (env->c != ch) {
		parse_error(env, "Unexpected char '%c', expected '%c'\n",
		            env->c, ch);
		return 0;
	}
	read_c(env);
	return 1;
}

#define EXPECT(c) if (expect_char(env, (c))) {} else return 0

static char *read_word(io_env_t *env)
{
	skip_ws(env);

	assert(obstack_object_size(&env->obst) == 0);
	while (true) {
		int c = env->c;
		switch (c) {
		case EOF:
		case ' ':
		case '\t':
		case '\n':
		case '\r':
			goto endofword;

		default:
			obstack_1grow(&env->obst, c);
			break;
		}
		read_c(env);
	}

endofword:
	obstack_1grow(&env->obst, '\0');
	return (char*)obstack_finish(&env->obst);
}

static char *read_string(io_env_t *env)
{
	skip_ws(env);
	if (env->c != '"') {
		parse_error(env, "Expected string, got '%c'\n", env->c);
		exit(1);
	}
	read_c(env);

	assert(obstack_object_size(&env->obst) == 0);
	while (env->c != '"') {
		if (env->c == EOF) {
			parse_error(env, "Unexpected EOF while parsing string\n");
			exit(1);
		}

		if (env->c == '\\') {
			read_c(env);
			switch (env->c) {
			case 'n':
				obstack_1grow(&env->obst, '\n');
				break;
			case '"':
			case '\\':
				obstack_1grow(&env->obst, env->c);
				break;
			default:
				parse_error(env, "Unknown escape sequence '\\%c'\n", env->c);
				exit(1);
			}
		} else {
			obstack_1grow(&env->obst, env->c);
		}
		read_c(env);
	}
	read_c(env);
	obstack_1grow(&env->obst, 0);

	return (char*)obstack_finish(&env->obst);
}

static ident *read_ident(io_env_t *env)
{
	char  *str = read_string(env);
	ident *res = new_id_from_str(str);
	obstack_free(&env->obst, str);
	return res;
}

/*
 * reads a "quoted string" or alternatively the token NULL
 */
static char *read_string_null(io_env_t *env)
{
	skip_ws(env);
	if (env->c == 'N') {
		char *str = read_word(env);
		if (strcmp(str, "NULL") == 0) {
			obstack_free(&env->obst, str);
			return NULL;
		}
	} else if (env->c == '"') {
		return read_string(env);
	}

	parse_error(env, "Expected \"string\" or NULL\n");
	exit(1);
}

static ident *read_ident_null(io_env_t *env)
{
	ident *res;
	char  *str = read_string_null(env);
	if (str == NULL)
		return NULL;

	res = new_id_from_str(str);
	obstack_free(&env->obst, str);
	return res;
}

static long read_long(io_env_t *env)
{
	long  result;
	char *str;

	skip_ws(env);
	if (!isdigit(env->c) && env->c != '-') {
		parse_error(env, "Expected number, got '%c'\n", env->c);
		exit(1);
	}

	assert(obstack_object_size(&env->obst) == 0);
	do {
		obstack_1grow(&env->obst, env->c);
		read_c(env);
	} while (isdigit(env->c));
	obstack_1grow(&env->obst, 0);

	str = (char*)obstack_finish(&env->obst);
	result = atol(str);
	obstack_free(&env->obst, str);

	return result;
}

static int read_int(io_env_t *env)
{
	return (int) read_long(env);
}

static unsigned read_unsigned(io_env_t *env)
{
	return (unsigned) read_long(env);
}

static size_t read_size_t(io_env_t *env)
{
	/* FIXME */
	return (size_t) read_unsigned(env);
}

static void expect_list_begin(io_env_t *env)
{
	skip_ws(env);
	if (env->c != '[') {
		parse_error(env, "Expected list, got '%c'\n", env->c);
		exit(1);
	}
	read_c(env);
}

static bool list_has_next(io_env_t *env)
{
	if (feof(env->file)) {
		parse_error(env, "Unexpected EOF while reading list");
		exit(1);
	}
	skip_ws(env);
	if (env->c == ']') {
		read_c(env);
		return false;
	}

	return true;
}

static ir_node *get_node_or_null(io_env_t *env, long nodenr)
{
	ir_node *node = (ir_node *) get_id(env, nodenr);
	if (node && node->kind != k_ir_node) {
		panic("Irn ID %ld collides with something else in line %d\n",
		      nodenr, env->line);
	}
	return node;
}

static ir_node *get_node_or_dummy(io_env_t *env, long nodenr)
{
	ir_node *node = get_node_or_null(env, nodenr);
	if (node == NULL) {
		node = new_r_Dummy(env->irg, mode_X);
		set_id(env, nodenr, node);
	}
	return node;
}

static ir_type *get_type(io_env_t *env, long typenr)
{
	ir_type *type = (ir_type *) get_id(env, typenr);
	if (type == NULL)
		panic("unknown type: %ld in line %d\n", typenr, env->line);
	else if (type->kind != k_type)
		panic("type ID %ld collides with something else in line %d\n",
		      typenr, env->line);
	return type;
}

static ir_type *read_type(io_env_t *env)
{
	return get_type(env, read_long(env));
}

static ir_entity *get_entity(io_env_t *env, long entnr)
{
	ir_entity *entity = (ir_entity *) get_id(env, entnr);
	if (entity == NULL) {
		parse_error(env, "unknown entity: %ld\n", entnr);
		exit(1);
	} else if (entity->kind != k_entity) {
		panic("Entity ID %ld collides with something else in line %d\n",
		      entnr, env->line);
	}

	return entity;
}

static ir_entity *read_entity(io_env_t *env)
{
	return get_entity(env, read_long(env));
}

static ir_mode *read_mode(io_env_t *env)
{
	char *str = read_string(env);
	size_t i, n;

	n = get_irp_n_modes();
	for (i = 0; i < n; i++) {
		ir_mode *mode = get_irp_mode(i);
		if (strcmp(str, get_mode_name(mode)) == 0) {
			obstack_free(&env->obst, str);