wsstree.c

The Kannel Open Source WAP and SMS gateway works as both an SMS gateway, for implementing keyword b

        ws_error_memory(compiler);
        return;
    }

    if (hash->defined) {
        ws_src_error(compiler, line, "redefinition of `%s'", name);
        ws_src_error(compiler,
                     compiler->functions[hash->findex].line,
                     "`%s' previously defined here", name);
        return;
    }

    hash->defined = WS_TRUE;
    hash->findex = f->findex;
}

/********************* Expressions **************************************/

void ws_expr_linearize(WsCompiler *compiler, WsExpression *expr)
{
    WsListItem *li;
    WsAsmIns *ins;

    switch (expr->type) {
    case WS_EXPR_COMMA:
        /* Linearize left. */
        ws_expr_linearize(compiler, expr->u.comma.left);

        /* Pop its result. */
        ws_asm_link(compiler, ws_asm_ins(compiler, expr->line, WS_ASM_POP));

        /* Linearize right */
        ws_expr_linearize(compiler, expr->u.comma.right);
        break;

    case WS_EXPR_ASSIGN:
        {
            WsNamespace *ns = ws_variable_lookup(compiler,
                                                 expr->u.assign.identifier);

            if (ns == NULL) {
                /* Unknown identifier. */
                ws_src_error(compiler, expr->line, "unknown variable `%s'",
                             expr->u.symbol);
                return;
            }

            if (expr->u.assign.op == '=') {
                /* Evaluate the expression. */
                ws_expr_linearize(compiler, expr->u.assign.expr);

                /* Store the value to the variable. */
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line,
                                            WS_ASM_P_STORE_VAR, ns->vindex));
            } else if (expr->u.assign.op == tADDA) {
                /* Linearize the expression. */
                ws_expr_linearize(compiler, expr->u.assign.expr);

                /* Add it to the variable. */
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line,
                                            WS_ASM_ADD_ASG, ns->vindex));
            } else if (expr->u.assign.op == tSUBA) {
                /* Linearize the expression. */
                ws_expr_linearize(compiler, expr->u.assign.expr);

                /* Substract it from the variable. */
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line,
                                            WS_ASM_SUB_ASG, ns->vindex));
            } else {
                /* Load the old value from the variable. */
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line,
                                            WS_ASM_P_LOAD_VAR, ns->vindex));

                /* Evaluate the expression. */
                ws_expr_linearize(compiler, expr->u.assign.expr);

                /* Perform the operand. */
                ins = NULL;
                switch (expr->u.assign.op) {
                case tMULA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_MUL);
                    break;

                case tDIVA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_DIV);
                    break;

                case tREMA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_REM);
                    break;

                case tADDA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_ADD);
                    break;

                case tSUBA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_SUB);
                    break;

                case tLSHIFTA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_LSHIFT);
                    break;

                case tRSSHIFTA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_RSSHIFT);
                    break;

                case tRSZSHIFTA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_RSZSHIFT);
                    break;

                case tANDA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_AND);
                    break;

                case tXORA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_XOR);
                    break;

                case tORA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_B_OR);
                    break;

                case tIDIVA:
                    ins = ws_asm_ins(compiler, expr->line, WS_ASM_IDIV);
                    break;

                default:
                    ws_fatal("ws_expr_linearize(): unknown assignment operand %x",
                             expr->u.assign.op);
                    break;
                }
                ws_asm_link(compiler, ins);

                /* Store the value to the variable. */
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line,
                                            WS_ASM_P_STORE_VAR, ns->vindex));
            }
            /* The value of the assignment expression is the value
               assigned.  So, we must load the value from the variable.
               This would also be a good place for the `dup' operand but
               we lose since we don't have it. */
            ws_asm_link(compiler, ws_asm_variable(compiler, expr->line,
                                                  WS_ASM_P_LOAD_VAR, ns->vindex));
        }
        break;

    case WS_EXPR_CONDITIONAL:
        {
            WsAsmIns *l_else = ws_asm_label(compiler, expr->line);
            WsAsmIns *l_end = ws_asm_label(compiler, expr->line);

            /* Linearize condition. */
            ws_expr_linearize(compiler, expr->u.conditional.e_cond);

            /* If the result if false, jump to the else-branch. */
            ws_asm_link(compiler, ws_asm_branch(compiler, expr->line,
                                                WS_ASM_P_TJUMP, l_else));

            /* Linearize the then-expression and jump out. */
            ws_expr_linearize(compiler, expr->u.conditional.e_then);
            ws_asm_link(compiler, ws_asm_branch(compiler, expr->line,
                                                WS_ASM_P_JUMP, l_end));

            /* The else-branch. */
            ws_asm_link(compiler, l_else);
            ws_expr_linearize(compiler, expr->u.conditional.e_else);

            /* Insert the end label. */
            ws_asm_link(compiler, l_end);
        }
        break;

    case WS_EXPR_LOGICAL:
        {
            WsAsmIns *l_out = ws_asm_label(compiler, expr->line);

            /* Linearize the left-hand size expression. */
            ws_expr_linearize(compiler, expr->u.logical.left);

            /* Short-circuit check.  The type of the logical expression is
                      the short-circuit byte-code operand. */
            ws_asm_link(compiler, ws_asm_ins(compiler, expr->line,
                                             expr->u.logical.type));
            ws_asm_link(compiler, ws_asm_branch(compiler, expr->line,
                                                WS_ASM_P_TJUMP, l_out));

            /* Linearize the right-hand size expression. */
            ws_expr_linearize(compiler, expr->u.logical.right);

            /* The result of a logical expression should be boolean.
             * Control statements do automatic conversion, but typeof()
	     * does not. */
            ws_asm_link(compiler, ws_asm_ins(compiler, expr->line,
                                         WS_ASM_TOBOOL));

            /* Insert the end label. */
            ws_asm_link(compiler, l_out);
        }
        break;

    case WS_EXPR_BINARY:
        /* Linearize left and right. */
        ws_expr_linearize(compiler, expr->u.binary.left);
        ws_expr_linearize(compiler, expr->u.binary.right);

        /* The type of the binary expression is the byte-code opcode. */
        ws_asm_link(compiler, ws_asm_ins(compiler, expr->line,
                                         expr->u.binary.type));
        break;

    case WS_EXPR_UNARY:
        /* Linearize the expression. */
        ws_expr_linearize(compiler, expr->u.unary.expr);

        /* The type of the unary expression is the byte-code opcode. */
        ws_asm_link(compiler, ws_asm_ins(compiler, expr->line,
                                         expr->u.unary.type));
        break;

    case WS_EXPR_UNARY_VAR:
        {
            WsNamespace *ns = ws_variable_lookup(compiler,
                                                 expr->u.unary_var.variable);
            if (ns == NULL) {
                /* An unknown identifier. */
                ws_src_error(compiler, expr->line, "unknown variable `%s'",
                             expr->u.unary_var.variable);
                return;
            }

            /* First, do the operation. */
            if (expr->u.unary_var.addp)
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line, WS_ASM_P_INCR_VAR,
                                            ns->vindex));
            else
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line, WS_ASM_DECR_VAR,
                                            ns->vindex));

            /* Second, load the new value of the variable. */
            ws_asm_link(compiler, ws_asm_variable(compiler, expr->line,
                                                  WS_ASM_P_LOAD_VAR, ns->vindex));
        }
        break;

    case WS_EXPR_POSTFIX_VAR:
        {
            WsNamespace *ns = ws_variable_lookup(compiler,
                                                 expr->u.postfix_var.variable);
            if (ns == NULL) {
                /* An unknown identifier. */
                ws_src_error(compiler, expr->line, "unknown variable `%s'",
                             expr->u.postfix_var.variable);
                return;
            }

            /* First, load the old value of the variable. */
            ws_asm_link(compiler, ws_asm_variable(compiler, expr->line,
                                                  WS_ASM_P_LOAD_VAR, ns->vindex));

            /* Second, do the operation. */
            if (expr->u.unary_var.addp)
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line, WS_ASM_P_INCR_VAR,
                                            ns->vindex));
            else
                ws_asm_link(compiler,
                            ws_asm_variable(compiler, expr->line, WS_ASM_DECR_VAR,
                                            ns->vindex));
        }
        break;

    case WS_EXPR_CALL:
        /* First, evaluate the arguments. */
        for (li = expr->u.call.arguments->head; li; li = li->next)
            ws_expr_linearize(compiler, li->data);

        /* Second, emit the call instruction. */
        switch (expr->u.call.type) {
        case ' ': 		/* LocalScriptFunctionCall */
            {
                WsFunctionHash *f = ws_function_hash(compiler, expr->u.call.name);

                if (f == NULL || !f->defined)
                {
                    ws_src_error(compiler, expr->line,
                                 "unknown local function `%s'",
                                 expr->u.call.name);
                    return;
                }

                /* Check that the function is called with correct amount
                          of arguments. */
                if (expr->u.call.arguments->num_items
                    != compiler->functions[f->findex].params->num_items)
                {
                    ws_src_error(compiler, expr->line,
                                 "invalid amount of arguments for `%s': "
                                 "expected %u, got %u",
                                 expr->u.call.name,
                                 compiler->functions[f->findex].params->num_items,
                                 expr->u.call.arguments->num_items);
                    return;
                }

                /* Emit assembler. */
                ws_asm_link(compiler, ws_asm_call(compiler, expr->line,
                                                  f->findex));
            }
            break;

        case '#': 		/* ExternalScriptFunctionCall */
            {
                WsPragmaUse *use = ws_hash_get(compiler->pragma_use_hash,
                                               expr->u.call.base);
                WsUInt16 findex;

                if (use == NULL)
                {
                    ws_src_error(compiler, expr->line,
                                 "unknown external compilation unit `%s'",
                                 expr->u.call.base);
                    return;
                }

                /* Insert the function name to the byte-code pool. */
                if (!ws_bc_add_const_utf8_string(
                        compiler->bc, &findex,
                        (unsigned char *) expr->u.call.name,
                        strlen(expr->u.call.name)))
                {
                    ws_error_memory(compiler);
                    return;
                }

                /* Emit assembler. */
                ws_asm_link(compiler,
                            ws_asm_call_url(compiler, expr->line,
                                            findex, use->urlindex,
                                            expr->u.call.arguments->num_items));
            }
            break;

        case '.': 		/* LibraryFunctionCall */
            {
                WsUInt16 lindex;
                WsUInt8 findex;
                WsUInt8 num_args;
                WsBool lindex_found;
                WsBool findex_found;

                if (!ws_stdlib_function(expr->u.call.base, expr->u.call.name,
                                        &lindex, &findex, &num_args,
                                        &lindex_found, &findex_found))
                {
                    if (!lindex_found)
                        ws_src_error(compiler, expr->line,
                                     "unknown system library `%s'",
                                     expr->u.call.base);
                    else
                        ws_src_error(compiler, expr->line,
                                     "unknown library function `%s.%s'",
                                     expr->u.call.base, expr->u.call.name);

                    return;
                }
                /* Check the argument count. */
                if (expr->u.call.arguments->num_items != num_args)
                {