static WsAsmIns *asm_alloc(WsCompiler *compiler, WsUInt16 type, WsUInt32 line)
{
WsAsmIns *ins = ws_f_calloc(compiler->pool_asm, 1, sizeof(*ins));
if (ins == NULL)
ws_error_memory(compiler);
else {
ins->type = type;
ins->line = line;
}
return ins;
}
static WsExpression *expr_alloc(WsCompiler *compiler,
WsExpressionType type, WsUInt32 line)
{
WsExpression *expr = ws_f_calloc(compiler->pool_stree, 1, sizeof(*expr));
if (expr == NULL)
ws_error_memory(compiler);
else {
expr->type = type;
expr->line = line;
}
return expr;
}
static WsStatement *stmt_alloc(WsCompiler *compiler, WsStatementType type,
WsUInt32 first_line, WsUInt32 last_line)
{
WsStatement *stmt = ws_f_calloc(compiler->pool_stree, 1, sizeof(*stmt));
if (stmt == NULL)
ws_error_memory(compiler);
else {
stmt->type = type;
stmt->first_line = first_line;
stmt->last_line = last_line;
}
return stmt;
}
void ws_list_append(WsCompiler *compiler, WsList *list, void *value)
{
WsListItem *item;
if (list == NULL)
/* A recovery code for previous memory allocation problems. */
return;
item = ws_f_calloc(compiler->pool_stree, 1, sizeof(*item));
if (item == NULL) {
ws_error_memory(compiler);
return;
}
item->data = value;
if (list->tail) {
list->tail->next = item;
list->tail = item;
} else
list->head = list->tail = item;
list->num_items++;
}
void ws_stmt_linearize(WsCompiler *compiler, WsStatement *stmt)
{
WsListItem *li;
WsAsmIns *ins;
switch (stmt->type) {
case WS_STMT_BLOCK:
for (li = stmt->u.block->head; li; li = li->next)
ws_stmt_linearize(compiler, li->data);
break;
case WS_STMT_VARIABLE:
linearize_variable_init(compiler, stmt->u.var, stmt->first_line);
break;
case WS_STMT_EMPTY:
/* Nothing here. */
break;
case WS_STMT_EXPR:
ws_expr_linearize(compiler, stmt->u.expr);
/* Pop the expressions result from the stack. Otherwise loops
could eventually cause stack overflows. */
ws_asm_link(compiler, ws_asm_ins(compiler, stmt->last_line, WS_ASM_POP));
break;
case WS_STMT_IF:
{
WsAsmIns *l_else = ws_asm_label(compiler,
(stmt->u.s_if.s_else
? stmt->u.s_if.s_else->first_line
: stmt->last_line));
WsAsmIns *l_end = ws_asm_label(compiler, stmt->last_line);
/* Linearize the expression. */
ws_expr_linearize(compiler, stmt->u.s_if.expr);
/* If the result is false, jump to the else-branch. */
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->first_line,
WS_ASM_P_TJUMP, l_else));
/* Else, execute the then-branch and jump to the end. */
ws_stmt_linearize(compiler, stmt->u.s_if.s_then);
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->last_line,
WS_ASM_P_JUMP, l_end));
/* Then else-branch. */
ws_asm_link(compiler, l_else);
/* Linearize the else-branch if it is present. */
if (stmt->u.s_if.s_else)
ws_stmt_linearize(compiler, stmt->u.s_if.s_else);
/* Insert the end label. */
ws_asm_link(compiler, l_end);
}
break;
case WS_STMT_FOR:
{
WsAsmIns *l_loop = ws_asm_label(compiler, stmt->first_line);
WsAsmIns *l_cont = ws_asm_label(compiler, stmt->first_line);
WsAsmIns *l_break = ws_asm_label(compiler, stmt->first_line);
WsContBreak *cb;
/* Store the labels to the compiler. */
cb = ws_f_calloc(compiler->pool_stree, 1, sizeof(*cb));
if (cb == NULL) {
ws_error_memory(compiler);
return;
}
cb->next = compiler->cont_break;
compiler->cont_break = cb;
cb->l_cont = l_cont;
cb->l_break = l_break;
/* Linearize the possible init code. */
if (stmt->u.s_for.init)
linearize_variable_init(compiler, stmt->u.s_for.init,
stmt->first_line);
else if (stmt->u.s_for.e1) {
/* Linearize the init. */
ws_expr_linearize(compiler, stmt->u.s_for.e1);
/* Pop the result. */
ws_asm_link(compiler, ws_asm_ins(compiler, stmt->first_line,
WS_ASM_POP));
}
/* Insert the loop label. */
ws_asm_link(compiler, l_loop);
/* Linearize the condition. */
if (stmt->u.s_for.e2) {
ws_expr_linearize(compiler, stmt->u.s_for.e2);
/* If false, jump out. */
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->first_line,
WS_ASM_P_TJUMP, l_break));
}
/* Linearize the body statement. */
ws_stmt_linearize(compiler, stmt->u.s_for.stmt);
/* Link the continue label. */
ws_asm_link(compiler, l_cont);
/* Linearize the update expression. */
if (stmt->u.s_for.e3) {
ws_expr_linearize(compiler, stmt->u.s_for.e3);
/* Pop the result. */
ws_asm_link(compiler, ws_asm_ins(compiler, stmt->first_line,
WS_ASM_POP));
}
/* Jump to the loop label to check the condition. */
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->last_line,
WS_ASM_P_JUMP, l_loop));
/* Insert the break label. */
ws_asm_link(compiler, l_break);
/* Pop the cont-break block. */
compiler->cont_break = compiler->cont_break->next;
}
break;
case WS_STMT_WHILE:
{
WsAsmIns *l_cont = ws_asm_label(compiler, stmt->first_line);
WsAsmIns *l_break = ws_asm_label(compiler,
stmt->u.s_while.stmt->last_line);
WsContBreak *cb;
/* Store the labels to the compiler. */
cb = ws_f_calloc(compiler->pool_stree, 1, sizeof(*cb));
if (cb == NULL) {
ws_error_memory(compiler);
return;
}
cb->next = compiler->cont_break;
compiler->cont_break = cb;
cb->l_cont = l_cont;
cb->l_break = l_break;
/* Insert the continue label. */
ws_asm_link(compiler, l_cont);
/* Linearize the expression. */
ws_expr_linearize(compiler, stmt->u.s_while.expr);
/* If false, jump out. */
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->first_line,
WS_ASM_P_TJUMP, l_break));
/* Linearize the body statement. */
ws_stmt_linearize(compiler, stmt->u.s_while.stmt);
/* And jump to the continue label to check the expression. */
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->last_line,
WS_ASM_P_JUMP, l_cont));
/* Insert the break label. */
ws_asm_link(compiler, l_break);
/* Pop the cont-break block. */
compiler->cont_break = compiler->cont_break->next;
}
break;
case WS_STMT_CONTINUE:
if (compiler->cont_break == NULL)
ws_src_error(compiler, stmt->first_line,
"continue statement not within a loop");
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->first_line,
WS_ASM_P_JUMP,
compiler->cont_break->l_cont));
break;
case WS_STMT_BREAK:
if (compiler->cont_break == NULL)
ws_src_error(compiler, stmt->first_line,
"break statement not within a loop");
ws_asm_link(compiler, ws_asm_branch(compiler, stmt->first_line,
WS_ASM_P_JUMP,
compiler->cont_break->l_break));
break;
case WS_STMT_RETURN:
if (stmt->u.expr) {
/* Linearize the return value and return it. */
ws_expr_linearize(compiler, stmt->u.expr);
ins = ws_asm_ins(compiler, stmt->first_line, WS_ASM_RETURN);
} else
/* Return an empty string. */
ins = ws_asm_ins(compiler, stmt->first_line, WS_ASM_RETURN_ES);
ws_asm_link(compiler, ins);
break;
}
}
