//Input: Two expressions x and y, and a relational operator op
//Output: One conditional expression x op y
NC* createConditionalExpression( NC *expr1, char *relOp, NC *expr2 )
{
NC *andExpr, *orExpr, *relExpr;
NC *newExpr1, *newExpr2;
NC *newExpr;
int operator;
operator = getRelOperatorIndex(relOp);
newExpr1 = copylist(expr1);
newExpr2 = copylist(expr2);
newExpr2 = negateExpression(newExpr2);
newExpr = (NC*) malloc (sizeof(NC));
Add_Sums(newExpr1, newExpr2, newExpr);
relExpr = (NC*) malloc (sizeof(NC));
relExpr->list = NULL;
relExpr->type = 'R';
relExpr->inc = operator;
relExpr->link = newExpr;
orExpr = (NC*) malloc (sizeof(NC));
orExpr->list = NULL;
orExpr->type = 'O';
orExpr->inc = 0;
orExpr->link = relExpr;
andExpr = (NC*) malloc (sizeof(NC));
andExpr->list = NULL;
andExpr->type = 'A';
andExpr->inc = 0;
andExpr->link = orExpr;
return andExpr;
}
static void untangleBranches(Stack *statements, int start, int stop,
Branchtype type, int indent)
{
Stack s;
Tree t;
int i, offset, end, hasElse, wasIf = 0;
for(i=start; i<stop; ++i)
{
s = statements[i];
t = s->data.tree;
if(s->target > i && t->action != SWFACTION_BRANCHIFTRUE)
{
/* it's a do loop */
int target = s->target;
if(s->target < start || s->target > stop)
error("stmt %i: do target (%i) outside scope (%i,%i)!",
i, s->target, start, stop);
putchar('\n');
INDENT
printf("do\n");
INDENT
printf("{\n");
s->target = -1;
untangleBranches(statements, i, target, BRANCH_DO, indent+1);
INDENT
printf("}\n");
INDENT
printf("while(");
listItem(statements[target]->data.tree->left, SWFACTION_END);
printf(");\n");
wasIf = 1;
i = target;
continue;
}
if(t->action == SWFACTION_BRANCHALWAYS)
error("stmt %i: unexpected unconditional branch!", i);
if(t->action != SWFACTION_BRANCHIFTRUE)
{
/* it's just a statement. */
if(wasIf)
putchar('\n');
INDENT
listItem(s, SWFACTION_END);
putchar(';');
putchar('\n');
wasIf = 0;
continue;
}
offset = (int)t->right;
if(offset < start || offset > stop)
error("stmt %i: branch target (%i) outside scope (%i,%i)!",
i, offset, start, stop);
if(offset < i)
error("stmt %i: Unexpected backwards branch!", i);
if(type==BRANCH_WHILE || type==BRANCH_DO)
{
if(offset == stop)
{
INDENT
printf("break;\n");
continue;
}
else if(offset == start)
{
INDENT
printf("continue;\n");
continue; /*ha!*/
}
}
if(statements[offset-1]->data.tree->action == SWFACTION_BRANCHALWAYS &&
(int)statements[offset-1]->data.tree->right == i)
{
/* it's a while loop */
putchar('\n');
INDENT
printf("while(");
listItem(negateExpression(t->left), SWFACTION_END);
printf(")\n");
if(i < offset-3)
{
INDENT
putchar('{');
putchar('\n');
}
untangleBranches(statements, i+1, offset-1, BRANCH_WHILE, indent+1);
if(i < offset-3)
{
INDENT
putchar('}');
putchar('\n');
}
wasIf = 1;
i = offset-1;
continue;
}
/* it's an if */
if(i>start)
putchar('\n');
if(statements[offset-1]->data.tree->action == SWFACTION_BRANCHALWAYS)
{
/* got an else */
hasElse = 1;
end = (int)statements[offset-1]->data.tree->right;
}
else
{
hasElse = 0;
end = offset;
}
if(end < start || end > stop)
error("stmt %i: else target (%i) outside scope (%i,%i)!",
i, end, start, stop);
if(end < i)
error("stmt %i: Unexpected backwards branch!", i);
INDENT
printf("if(");
/* XXX - would like to reverse else and if if expression is already
negated.. */
listItem(negateExpression(t->left), SWFACTION_END);
putchar(')');
putchar('\n');
if(i < offset-(hasElse?3:2))
{
INDENT
putchar('{');
putchar('\n');
}
/* if hasElse, i+1 to offset-1 */
untangleBranches(statements, i+1, offset-(hasElse?1:0), BRANCH_IF, indent+1);
if(i < offset-(hasElse?3:2))
{
INDENT
putchar('}');
putchar('\n');
}
if(hasElse)
{
INDENT
printf("else\n");
if(offset+2 < end)
{
INDENT
putchar('{');
putchar('\n');
}
untangleBranches(statements, offset, end, BRANCH_ELSE, indent+1);
if(offset+2 < end)
{
INDENT
putchar('}');
putchar('\n');
}
}
wasIf = 1;
i = end-1;
}
}
