gambas-source-code/main/gbc/gbc_trans_ctrl.c

/***************************************************************************

  trans_ctrl.c

  Control structures compiler

  (c) 2000-2007 Benoit Minisini <gambas@users.sourceforge.net>

  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 1, 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 the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

***************************************************************************/

#define _TRANS_CTRL_C

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "gb_common.h"
#include "gb_error.h"
#include "gbc_compile.h"
#include "gbc_trans.h"
#include "gb_code.h"
#include "gb_limit.h"

/*#define DEBUG*/
/*#define DEBUG_GOTO*/

static int ctrl_level;
static int ctrl_id;
static int ctrl_local;

static TRANS_CTRL ctrl_data[MAX_CTRL_LEVEL];

static TRANS_CTRL *current_ctrl;

static TRANS_GOTO *goto_info;
static TRANS_LABEL *label_info;
static short *ctrl_parent;


static void control_set_value(int value)
{
  if (ctrl_level <= 0)
    return;

  current_ctrl->value = value;
}


static int control_get_value()
{
  if (ctrl_level <= 0)
    return 0;

  return current_ctrl->value;
}


static void control_add_pos(short **tab_pos, short pos)
{
  if (!(*tab_pos))
    ARRAY_create(tab_pos);

  *((short *)ARRAY_add(tab_pos)) = pos;
}


static void control_add_current_pos()
{
  control_add_pos(&current_ctrl->pos, CODE_get_current_pos());
}

static void control_add_this_pos(ushort pos)
{
  control_add_pos(&current_ctrl->pos, pos);
}


static void control_jump_each_pos_with(short *tab_pos)
{
  int i;

  if (!tab_pos)
    return;

  for (i = 0; i < ARRAY_count(tab_pos); i++)
    CODE_jump_length(tab_pos[i], CODE_get_current_pos());
}


static void control_jump_each_pos()
{
  control_jump_each_pos_with(current_ctrl->pos);
}


static TRANS_CTRL *control_get_inner(void)
{
  int level = ctrl_level;
  TRANS_CTRL *ctrl_look;

  for(;;)
  {
    if (!level)
      return NULL;

    level--;
    ctrl_look = &ctrl_data[level];

    if ((ctrl_look->type == RS_DO)
        || (ctrl_look->type == RS_WHILE)
        || (ctrl_look->type == RS_REPEAT)
        || (ctrl_look->type == RS_FOR)
        || (ctrl_look->type == RS_EACH))
      return ctrl_look;
  }
}


static TRANS_CTRL *control_get_inner_with(void)
{
  int level = ctrl_level;
  TRANS_CTRL *ctrl_look;

  for(;;)
  {
    if (!level)
      return NULL;

    level--;
    ctrl_look = &ctrl_data[level];

    if (ctrl_look->type == RS_WITH)
      return ctrl_look;
  }
}


static void add_goto(int index)
{
  TRANS_GOTO *info;

  if (goto_info == NULL)
    ARRAY_create(&goto_info);

  info = ARRAY_add(&goto_info);
  info->index = index;
  info->pos = CODE_get_current_pos();
  info->ctrl_id = (ctrl_level == 0) ? 0 : current_ctrl->id;
  info->line = JOB->line;

  #ifdef DEBUG_GOTO
    printf("add_goto: ctrl_id = %d (%ld)\n", info->ctrl_id, ARRAY_count(goto_info));
  #endif

  CODE_jump();
}


static void control_enter(int type)
{
  short *parent;

  if (ctrl_level >= MAX_CTRL_LEVEL)
    THROW("Too many nested control structures.");

  ctrl_id++;

  current_ctrl = &ctrl_data[ctrl_level];

  current_ctrl->type = type;
  current_ctrl->value = 0;
  current_ctrl->pos = NULL;
  current_ctrl->state = 0;
  current_ctrl->local = ctrl_local;
  current_ctrl->id = ctrl_id;
  current_ctrl->loop_var = -1;

  parent = ARRAY_add(&ctrl_parent);

  if (ctrl_level == 0)
    *parent = 0;
  else
    *parent = ctrl_data[ctrl_level - 1].id;

  switch (type)
  {
    case RS_FOR:
    case RS_EACH:
      ctrl_local += 2;
      break;

    case RS_SELECT:
    case RS_WITH:
      ctrl_local += 1;
      break;
  }

  JOB->func->nctrl = Max(JOB->func->nctrl, ctrl_local - JOB->func->nlocal);

  ctrl_level++;
}


static void control_leave()
{
  control_jump_each_pos_with(current_ctrl->pos_break);

  ARRAY_delete(&current_ctrl->pos);
  ARRAY_delete(&current_ctrl->pos_break);
  ARRAY_delete(&current_ctrl->pos_continue);

  ctrl_local = current_ctrl->local;

  ctrl_level--;

  if (ctrl_level > 0)
    current_ctrl = &ctrl_data[ctrl_level - 1];
  else
    current_ctrl = NULL;
}


static void control_check(int type, const char *msg1, const char *msg2)
{
  if (ctrl_level <= 0)
    THROW(msg1);

  if (current_ctrl->type != type)
    THROW(msg2);
}

static void control_check_two(int type1, int type2, const char *msg1, const char *msg2)
{
  if (ctrl_level <= 0)
    THROW(msg1);

  if (current_ctrl->type != type1 && current_ctrl->type != type2)
    THROW(msg2);
}

static void control_check_loop_var(short var)
{
	int i;

	for (i = 0; i < (ctrl_level - 1); i++)
	{
		if (ctrl_data[i].loop_var == var)
			THROW("Loop variable already in use");
	}

	current_ctrl->loop_var = var;
}


void TRANS_control_init()
{
  ctrl_level = 0;
  ctrl_id = 0;
  current_ctrl = NULL;

  goto_info = NULL;

  label_info = NULL;

  ctrl_local = JOB->func->nlocal;
  JOB->func->nctrl = 0;

  ARRAY_create(&ctrl_parent);
}


void TRANS_control_exit()
{
  int i;
  CLASS_SYMBOL *sym;
  int line;
  TRANS_LABEL *label;
  short id;

  /* R<>olution des GOTO */

  if (goto_info)
  {
    line = JOB->line;

    for (i = 0; i < ARRAY_count(goto_info); i++)
    {
      JOB->line = goto_info[i].line;
      /*printf("%d\n", JOB->line);*/

      sym = CLASS_get_symbol(JOB->class, goto_info[i].index);

      if (TYPE_get_kind(sym->local.type) != TK_LABEL)
        THROW("Label '&1' not declared", TABLE_get_symbol_name(JOB->class->table, goto_info[i].index));

      label = &label_info[sym->local.value];

      id = goto_info[i].ctrl_id;

      for(;;)
      {
        if (label->ctrl_id == id)
          break;

        if (id == 0)
          THROW("Forbidden GOTO");

        #ifdef DEBUG_GOTO
          printf("id = %d ctrl_parent[id - 1] = %d (%ld)\n", id, ctrl_parent[id - 1], ARRAY_count(ctrl_parent));
        #endif
        id = ctrl_parent[id - 1];
      }

      CODE_jump_length(goto_info[i].pos, label->pos);
    }

    JOB->line = line;
  }

  /* Remove previously declared labels */

  if (label_info)
  {
    for (i = 0; i < ARRAY_count(label_info); i++)
    {
      sym = CLASS_get_symbol(JOB->class, label_info[i].index);
      TYPE_clear(&sym->local.type);
    }
  }

  ARRAY_delete(&goto_info);
  ARRAY_delete(&ctrl_parent);
  ARRAY_delete(&label_info);

  /* On ne doit pas laisser une structure de controle ouverte */

  if (ctrl_level == 0) return;

  switch (ctrl_data[ctrl_level - 1].type)
  {
    case RS_IF:
      THROW("ENDIF missing");
    case RS_FOR:
    case RS_EACH:
      THROW("NEXT missing");
    case RS_DO:
      THROW("LOOP missing");
    case RS_REPEAT:
      THROW("UNTIL missing");
    case RS_WHILE:
      THROW("WEND missing");
    case RS_SELECT:
      THROW("END SELECT missing");
    case RS_WITH:
      THROW("END WITH missing");
  }
}

static ushort trans_jump_if(bool if_true)
{
	ushort pos;
	
	if (CODE_check_jump_not())
		if_true = !if_true;
	
	pos = CODE_get_current_pos();
		
	if (if_true)
		CODE_jump_if_true();
	else
		CODE_jump_if_false();
		
	return pos;
}

static void trans_endif(void)
{
  if (current_ctrl->state == 0)
    CODE_jump_length(control_get_value(), CODE_get_current_pos());

  control_jump_each_pos();
}

static void trans_else(void)
{
  control_add_current_pos();
  CODE_jump();

  CODE_jump_length(control_get_value(), CODE_get_current_pos());

  current_ctrl->state = 1;
}

static void trans_if(void)
{
  int mode = RS_NONE;
  char *msg;

  TRANS_expression(FALSE);

  if (PATTERN_is(*JOB->current, RS_AND))
  {
    mode = RS_AND;
    msg = "AND IF";
  }
  else if (PATTERN_is(*JOB->current, RS_OR))
  {
    mode = RS_OR;
    msg = "OR IF";
  }

  if (mode != RS_NONE)
  {
    control_enter(RS_IF);

    // IF NOT A THEN

    /*control_set_value(CODE_get_current_pos());

    if (mode == RS_AND)
      CODE_jump_if_true();
    else
      CODE_jump_if_false();*/
      
    control_set_value(trans_jump_if(mode == RS_AND));

    //   FALSE
    CODE_ignore_next_stack_usage();
    CODE_push_boolean(mode != RS_AND);

    for(;;)
    {
      if (!PATTERN_is(*JOB->current, mode))
        break;
      JOB->current++;

      TRANS_want(RS_IF, msg);

      // ELSE IF NOT B THEN

      trans_else();

      TRANS_expression(FALSE);

      /*control_set_value(CODE_get_current_pos());

      if (mode == RS_AND)
        CODE_jump_if_true();
      else
        CODE_jump_if_false();*/
        
      control_set_value(trans_jump_if(mode == RS_AND));

      //   FALSE
      CODE_ignore_next_stack_usage();
      CODE_push_boolean(mode != RS_AND);

      if (PATTERN_is(*JOB->current, RS_THEN) || PATTERN_is_newline(*JOB->current))
        break;
    }

    // ELSE

    trans_else();

    //   TRUE
    // ENDIF

    CODE_push_boolean(mode == RS_AND);
    trans_endif();

    control_leave();
  }

  if (PATTERN_is(*JOB->current, RS_THEN))
  	JOB->current++;
	else if (!PATTERN_is_newline(*JOB->current))
    THROW("Syntax error. THEN expected");

  /*control_set_value(CODE_get_current_pos());
  CODE_jump_if_false();*/
	control_set_value(trans_jump_if(FALSE));
}

static void trans_else_if(void)
{
  trans_else();
  current_ctrl->state = 0;
  trans_if();
}


void TRANS_if()
{
  control_enter(RS_IF);

  trans_if();

  if (PATTERN_is_newline(*JOB->current))
    return;

  TRANS_statement();
  TRANS_endif();
}


void TRANS_else()
{
  control_check(RS_IF, "ELSE without IF", "Unexpected ELSE");

  if (current_ctrl->state)
    THROW("Unexpected ELSE");

  if (TRANS_is(RS_IF))
    trans_else_if();
  else
    trans_else();
}


void TRANS_endif()
{
  control_check(RS_IF, "ENDIF without IF", "Unexpected ENDIF");
  trans_endif();
  control_leave();
}


void TRANS_goto()
{
  int index;

  if (!PATTERN_is_identifier(*JOB->current))
    THROW(E_SYNTAX);

  index = PATTERN_index(*JOB->current);
  JOB->current++;

  add_goto(index);
}


void TRANS_do(PATTERN type)
{
  boolean is_until;

  control_enter(type);
  control_set_value(CODE_get_current_pos());

  if (type == RS_REPEAT)
    return;

  is_until = PATTERN_is(*JOB->current, RS_UNTIL);

  if (PATTERN_is(*JOB->current, RS_WHILE)
      || is_until)
  {

    JOB->current++;

    TRANS_expression(FALSE);

    /*control_add_current_pos();

    if (is_until)
      CODE_jump_if_true();
    else
      CODE_jump_if_false();*/
      
    control_add_this_pos(trans_jump_if(is_until));
    
  }
}


void TRANS_loop(PATTERN type)
{
  ushort pos;

  boolean is_until;

  if (type == RS_LOOP)
    control_check(RS_DO, "LOOP without DO", "Unexpected LOOP");
  else if (type == RS_UNTIL)
    control_check(RS_REPEAT, "UNTIL without REPEAT", "Unexpected UNTIL");
  else if (type == RS_WEND)
    control_check(RS_WHILE, "WEND without WHILE", "Unexpected WEND");

  control_jump_each_pos_with(current_ctrl->pos_continue);

  is_until = PATTERN_is(*JOB->current, RS_UNTIL);

  if ((type != RS_WEND) && (PATTERN_is(*JOB->current, RS_WHILE) || is_until))
  {
    JOB->current++;

    TRANS_expression(FALSE);

    /*pos = CODE_get_current_pos();

    if (is_until)
      CODE_jump_if_false();
    else
      CODE_jump_if_true();*/
      
    pos = trans_jump_if(!is_until);
    
    CODE_jump_length(pos, control_get_value());
  }
  else
  {
    pos = CODE_get_current_pos();
    CODE_jump();
    CODE_jump_length(pos, control_get_value());
  }

  control_jump_each_pos();
  control_leave();
}


static void trans_select_break(boolean do_not_add_pos)
{
  if (current_ctrl->value)
  {
    if (!do_not_add_pos)
    {
      control_add_current_pos();
      CODE_jump();
    }

    CODE_jump_length(current_ctrl->value, CODE_get_current_pos());
  }
}


void TRANS_select(void)
{
  control_enter(RS_SELECT);

  if (PATTERN_is(*JOB->current, RS_CASE))
    JOB->current++;

  TRANS_expression(FALSE);
  CODE_pop_ctrl(current_ctrl->local);
}


void TRANS_case(void)
{
  int i;
  short pos;
  short local;

  control_check(RS_SELECT, "CASE without SELECT", "Unexpected CASE");

  trans_select_break(FALSE);

  local = current_ctrl->local;

  control_enter(RS_CASE);

  for(i = 0; ; i++)
  {
    if (i > MAX_CASE_EXPR)
      THROW("Too many expressions in CASE");

    /*CODE_dup();
    TRANS_expression(FALSE);
    CODE_op(C_EQ, 2);*/

    TRANS_expression(FALSE);

    if (TRANS_is(RS_TO))
    {
      CODE_push_local(local);
      CODE_op(C_LE, 2, TRUE);
      CODE_push_local(local);
      TRANS_expression(FALSE);
      CODE_op(C_LE, 2, TRUE);
      CODE_op(C_AND, 2, TRUE);
    }
    else
    {
      CODE_push_local(local);
      CODE_op(C_EQ, 2, TRUE);
    }

    if (!PATTERN_is(*JOB->current, RS_COMMA))
    {
      pos = CODE_get_current_pos();
      CODE_jump_if_false();
      break;
    }

    control_add_current_pos();
    CODE_jump_if_true();

    JOB->current++;
  }

  control_jump_each_pos();
  control_leave();

  current_ctrl->value = pos;
}


void TRANS_default(void)
{
  control_check(RS_SELECT, "DEFAULT without SELECT", "Unexpected DEFAULT");

  trans_select_break(FALSE);

  current_ctrl->value = 0; /*CODE_get_current_pos();*/
}


void TRANS_end_select(void)
{
  control_check(RS_SELECT, "END SELECT without SELECT", "Unexpected END SELECT");

  /*
  if (current_ctrl->value)
    CODE_jump_length(current_ctrl->value, CODE_get_current_pos());
  */

  trans_select_break(TRUE);

  control_jump_each_pos();

  control_leave();
}


void TRANS_break(void)
{
  TRANS_CTRL *ctrl_inner = control_get_inner();

  if (!ctrl_inner)
    THROW("Unexpected BREAK");

  control_add_pos(&ctrl_inner->pos_break, CODE_get_current_pos());
  CODE_jump();
}


void TRANS_continue(void)
{
  TRANS_CTRL *ctrl_inner = control_get_inner();

  if (!ctrl_inner)
    THROW("Unexpected CONTINUE");

  control_add_pos(&ctrl_inner->pos_continue, CODE_get_current_pos());
  CODE_jump();
}


void TRANS_return(void)
{
  if (FUNCTION_is_procedure(JOB->func))
  {
    if (!(PATTERN_is_newline(*JOB->current) || PATTERN_is_end(*JOB->current)))
      THROW("Return value datatype not specified in function declaration");
  }

  if (PATTERN_is_newline(*JOB->current) || PATTERN_is_end(*JOB->current))
    CODE_return(0);
  else
  {
    TRANS_expression(FALSE);
    CODE_return(1);
  }
}


void TRANS_for(void)
{
  PATTERN *loop_var;
  short local;

  control_enter(RS_FOR);

  loop_var = JOB->current;

  TRANS_affectation(FALSE);

  if (!CODE_check_pop_local_last(&local))
    THROW("Loop variable must be local");

	control_check_loop_var(local);

	TRANS_want(RS_TO, "TO");

  TRANS_expression(FALSE);

  if (PATTERN_is(*JOB->current, RS_STEP))
  {
    JOB->current++;
    TRANS_expression(FALSE);
  }
  else
  {
    CODE_push_number(1);
  }

  /*CODE_pop_ctrl(current_ctrl->local + 1);
  CODE_pop_ctrl(current_ctrl->local);*/

  if (!PATTERN_is_newline(*JOB->current))
    THROW(E_UNEXPECTED, READ_get_pattern(JOB->current));

  CODE_jump_first(current_ctrl->local);

  control_set_value(CODE_get_current_pos());

  /*
  current = JOB->current;
  JOB->current = loop_var;
  TRANS_expression(FALSE);
  JOB->current = current;
  */

  control_add_current_pos();
  CODE_jump_next();
  CODE_pop_local(local);

  /*
  current = JOB->current;
  JOB->current = loop_var;
  TRANS_expression(FALSE);

  if (!CODE_popify_last())
    ERROR_panic("Cannot popify FOR expression ??");

  JOB->current = current;
  */
}


void TRANS_for_each(void)
{
  PATTERN *iterator = JOB->current;
  PATTERN *save;
  bool var = TRUE;

  while (!PATTERN_is(*JOB->current, RS_IN))
  {
    if (PATTERN_is_newline_end(*JOB->current))
    {
      JOB->current = iterator;
      var = FALSE;
      break;
    }
    JOB->current++;
  }

  control_enter(RS_EACH);

  if (var)
    JOB->current++;

  TRANS_expression(FALSE);

  /*CODE_pop_ctrl(current_ctrl->local);*/

  CODE_first(current_ctrl->local);

  control_set_value(CODE_get_current_pos());
  control_add_current_pos();

  if (var)
  {
    CODE_next(FALSE);

    save = JOB->current;
    JOB->current = iterator;

    TRANS_expression(FALSE);

    if (!CODE_popify_last())
      THROW("Invalid assignment");

    JOB->current = save;
  }
  else
    CODE_next(TRUE);

  return;
}


void TRANS_next(void)
{
  ushort pos;

  control_check_two(RS_FOR, RS_EACH, "`Next' without `For'", "Unexpected `Next'");

  /*
  if (current_ctrl->type == RS_FOR)
  {
    control_jump_each_pos_with(current_ctrl->pos_continue);

    pos = CODE_get_current_pos();
    CODE_jump();
    CODE_jump_length(pos, control_get_value());

    control_jump_each_pos();
    control_leave();
  }
  else
  {
  */
  control_jump_each_pos_with(current_ctrl->pos_continue);

  pos = CODE_get_current_pos();
  CODE_jump();
  CODE_jump_length(pos, control_get_value());

  control_jump_each_pos();
  control_leave();
}


void TRANS_try(void)
{
  static int no_try = 0;
  ushort pos;

  if (no_try)
  {
    no_try = 0;
    THROW("Cannot use TRY twice");
  }

  pos = CODE_get_current_pos();
  CODE_try();

  no_try++;
  TRANS_statement();
  no_try--;

  CODE_jump_length(pos, CODE_get_current_pos());
  CODE_end_try();
}


void TRANS_finally(void)
{
  ushort pos = CODE_get_current_pos();

  if ((JOB->func->finally != 0)
      || (JOB->func->catch != 0)
      || (pos == 0))
    THROW("Unexpected FINALLY");

  JOB->func->finally = pos;
}


void TRANS_catch(void)
{
  ushort pos = CODE_get_current_pos();

  if ((JOB->func->catch != 0)
      || (pos == 0))
    THROW("Unexpected CATCH");

  CODE_catch();

  JOB->func->catch = CODE_get_current_pos();
}


void TRANS_label(void)
{
  CLASS_SYMBOL *sym;
  int sym_index;
  TRANS_LABEL *label;

  sym_index = PATTERN_index(*JOB->current);
  JOB->current++;

  sym = CLASS_declare(JOB->class, sym_index, FALSE);

  if (label_info == NULL)
    ARRAY_create(&label_info);

  sym->local.type = TYPE_make(T_NULL, 0L, TK_LABEL);
  sym->local.value = ARRAY_count(label_info);

  label = ARRAY_add(&label_info);

  label->index = sym_index;
  label->ctrl_id = (ctrl_level == 0) ? 0 : current_ctrl->id;
  label->pos = CODE_get_current_pos();

  #ifdef DEBUG_GOTO
  printf("TRANS_label: %.*s ctrl_id = %d\n", sym->symbol.len, sym->symbol.name, label->ctrl_id);
  #endif

  /* on saute le ':' */
  JOB->current++;
}


void TRANS_with(void)
{
  control_enter(RS_WITH);

  if (!TRANS_affectation(TRUE))
    TRANS_expression(FALSE);

  CODE_pop_ctrl(current_ctrl->local);
}


void TRANS_use_with(void)
{
  TRANS_CTRL *ctrl_inner = control_get_inner_with();

  if (ctrl_inner == NULL)
    THROW("Syntax Error. Point syntax used outside of WITH / END WITH");

  CODE_push_local(ctrl_inner->local);
}


void TRANS_end_with(void)
{
  control_check(RS_WITH, "END WITH without WITH", "Unexpected END WITH");

  control_leave();
}


void TRANS_raise(void)
{
  CLASS_SYMBOL *sym;
  int np;

  if (!PATTERN_is_identifier(*JOB->current))
    THROW("Syntax error in event name");

  sym = CLASS_get_symbol(JOB->class, PATTERN_index(*JOB->current));

  JOB->current++;

  if (TYPE_get_kind(sym->global.type) != TK_EVENT)
    THROW("Unknown event");

  if (TYPE_is_static(JOB->func->type))
    THROW("Cannot raise events in static function");

  CODE_push_event(sym->global.value);

  np = 0;

  if (TRANS_is(RS_LBRA))
  {
    for (;;)
    {
      if (TRANS_is(RS_RBRA))
        break;

      if (np > 0)
        TRANS_want(RS_COMMA, "comma");

      if (np >= MAX_PARAM_FUNC)
        THROW("Too many arguments");

      TRANS_expression(FALSE);
      np++;
    }
  }

  CODE_call(np);

  if (TRANS_in_affectation == 0)
    CODE_drop();

  /*if (TRANS_is(RS_AS))
    TRANS_reference();
  else
    CODE_drop();*/
}