int Parser::expression(int pos, int status) { int isputs = 0; if(tok.skip("$")) { // global varibale if(is_asgmt()) asgmt(); } else if(tok.skip("require")) { make_require(); } else if(tok.skip("def")) { blocksCount++; make_func(); } else if(tok.skip("module")) { blocksCount++; module = tok.tok[tok.pos++].val; eval(0, NON); module = ""; } else if(funcs.inside == false && !tok.is("def", 1) && !tok.is("module", 1) && !tok.is("$", 1) && !tok.is(";", 1) && module == "") { // main func entry funcs.inside = true; funcs.now++; funcs.append("main", ntv.count, 0); // append funcs ntv.genas("push ebp"); ntv.genas("mov ebp esp"); uint32_t espBgn = ntv.count + 2; ntv.genas("sub esp 0"); ntv.gencode(0x8b); ntv.gencode(0x75); ntv.gencode(0x0c); // mov esi, 0xc(%ebp) eval(0, BLOCK_NORMAL); ntv.gencode(0x81); ntv.gencode(0xc4); ntv.gencode_int32(ADDR_SIZE * (var.focus().size() + 6)); // add %esp nn ntv.gencode(0xc9);// leave ntv.gencode(0xc3);// ret ntv.gencode_int32_insert(ADDR_SIZE * (var.focus().size() + 6), espBgn); funcs.inside = false; } else if(is_asgmt()) { asgmt(); } else if((isputs=tok.skip("puts")) || tok.skip("print")) { do { ExprType et = expr_entry(); ntv.genas("push eax"); if(et.is_type(T_STRING)) { ntv.gencode(0xff); ntv.gencode(0x56); ntv.gencode(4);// call *0x04(esi) putString } else { ntv.gencode(0xff); ntv.gencode(0x16); // call (esi) putNumber } ntv.genas("add esp 4"); } while(tok.skip(",")); // for new line if(isputs) { ntv.gencode(0xff); ntv.gencode(0x56); ntv.gencode(8);// call *0x08(esi) putLN } } else if(tok.skip("for")) { blocksCount++; asgmt(); if(!tok.skip(",")) error("error: %d: expected ','", tok.tok[tok.pos].nline); make_while(); } else if(tok.skip("while")) { blocksCount++; make_while(); } else if(tok.skip("return")) { make_return(); } else if(tok.skip("if")) { blocksCount++; make_if(); } else if(tok.skip("else")) { uint32_t end; ntv.gencode(0xe9); end = ntv.count; ntv.gencode_int32(0);// jmp while end ntv.gencode_int32_insert(ntv.count - pos - 4, pos); eval(end, BLOCK_NORMAL); return 1; } else if(tok.skip("elsif")) { uint32_t endif, end; ntv.gencode(0xe9); endif = ntv.count; ntv.gencode_int32(0);// jmp while end ntv.gencode_int32_insert(ntv.count - pos - 4, pos); expr_entry(); // if condition ntv.gencode(0x83); ntv.gencode(0xf8); ntv.gencode(0x00);// cmp eax, 0 ntv.gencode(0x75); ntv.gencode(0x05); // jne 5 tok.skip(";"); ntv.gencode(0xe9); end = ntv.count; ntv.gencode_int32(0);// jmp while end eval(end, BLOCK_NORMAL); ntv.gencode_int32_insert(ntv.count - endif - 4, endif); return 1; } else if(tok.skip("break")) { make_break(); } else if(tok.skip("end")) { blocksCount--; if(status == NON) return 1; if(status == BLOCK_NORMAL) { ntv.gencode_int32_insert(ntv.count - pos - 4, pos); } else if(status == BLOCK_FUNC) funcs.inside = false; return 1; } else if(!tok.skip(";")) { expr_entry(); } return 0; }
/* * Make the given NODE simple - i.e. return a temporary for complex subtrees * The appropriate code is also generated and pushed onto the code stack */ value *make_simple(environment *env, NODE *node, int flag, int return_type) { int i_value = 0; char *s_tmp = NULL; value *val1 = NULL, *val2 = NULL, *temporary = NULL, *temp = NULL; static int if_count = 0; static int while_count = 0; tac_quad *temp_quad = NULL; environment *new_env = NULL; if (node==NULL) return NULL; switch(type_of(node)) { case LEAF: return make_simple(env, node->left, flag, return_type); case CONSTANT: i_value = cast_from_node(node)->value; s_tmp = malloc(sizeof(char) * 25); sprintf(s_tmp, "%d", i_value); return int_value(i_value); case IDENTIFIER: return string_value(cast_from_node(node)->lexeme); case IF: build_if_stmt(env, node, ++if_count, NULL, NULL, flag, return_type); return NULL; case BREAK: s_tmp = malloc(sizeof(char) * 25); sprintf(s_tmp, "__while%dend", while_count); append_code(make_goto(s_tmp)); return NULL; case CONTINUE: s_tmp = malloc(sizeof(char) * 25); sprintf(s_tmp, "__while%d", while_count); append_code(make_goto(s_tmp)); return NULL; case WHILE: build_while_stmt(env, node, ++while_count, ++if_count, flag, return_type); return NULL; case '=': if (flag == INTERPRET_FN_SCAN) return NULL; val1 = make_simple(env, node->left, flag, return_type); val2 = make_simple(env, node->right, flag, return_type); if (val2 && val2->value_type!=VT_INTEGR && val2->value_type!=VT_FUNCTN) { if (val2->value_type == VT_STRING) { val2 = get(env, val2->data.string_value); } else { val2 = get(env, val2->identifier); } if (!val2) fatal("Undeclared identifier"); } /* Check the LHS variable has already been defined */ temp = get(env, to_string(val1)); assert(temp!=NULL, "Variable not defined"); /* Type check the assignment */ type_check_assignment(val1, val2, vt_type_convert(temp->value_type)); temporary = assign(env, val1, val2, 0); if (flag != INTERPRET_FN_SCAN) append_code(make_quad_value("=", val2, NULL, temporary, TT_ASSIGN, 0)); return NULL; case '*': case '/': case '>': case '<': case '%': case '-': case '+': case NE_OP: case LE_OP: case GE_OP: case EQ_OP: temporary = generate_temporary(env, int_value(0)); val1 = make_simple(env, node->left, flag, return_type); val2 = make_simple(env, node->right, flag, return_type); if (val1->value_type==VT_STRING) val1 = get(env, correct_string_rep(val1)); if (val2->value_type==VT_STRING) val2 = get(env, correct_string_rep(val2)); assert(val1 != NULL, "Operand value 1 must not be null"); assert(val2 != NULL, "Operand value 2 must not be null"); if (flag != INTERPRET_FN_SCAN) append_code(make_quad_value(type_to_string(type_of(node)), val1, val2, temporary, TT_OP, type_of(node))); return temporary; case '~': if (flag != INTERPRET_PARAMS && flag!=INTERPRET_FN_SCAN) { /* Params should not be registered, because at this point we're not in the correct environment */ register_variable_subtree_tac(env, node, VT_ANY); } val1 = make_simple(env, node->left, flag, return_type); val2 = make_simple(env, node->right, flag, return_type); if (flag == INTERPRET_PARAMS) { return int_param(to_string(val2), to_int(env, val1)); } return NULL; case 'D': /* val1 is FN definition */ /* val1 is executed in current environment */ val1 = make_simple(env, node->left, flag, return_type); /* New FN body environment */ new_env = create_environment(env); if (val1!=NULL) { /* Point function to the correct fn body */ val1->data.func->node_value = node->right; /* Store function definition in environment */ val2 = store_function(env, val1, new_env); } if (flag != INTERPRET_FN_SCAN) { /* Write out FN Name label */ append_code(make_begin_fn(val2)); append_code(make_fn_def(val2)); /* Make init frame */ temp_quad = make_init_frame(); append_code(temp_quad); /* Define parameters with default empty values */ register_params(new_env, val2->data.func->params); append_code(make_fn_body(val2)); /* Look inside fn body */ val2 = make_simple(new_env, node->right, EMBEDDED_FNS, val1->data.func->return_type); /* Update prepare frame with environment size */ temp_quad->operand1 = int_value(env_size(new_env)); /* Write end of function marker */ append_code(make_end_fn(val2)); } return NULL; case 'd': /* val1 is the type */ val1 = make_simple(env, node->left, flag, return_type); /* val2 is fn name & params */ val2 = make_simple(env, node->right, flag, return_type); /* Store return type */ val2->data.func->return_type = to_int(env, val1); return val2; case 'F': /* FN name in val1 */ val1 = make_simple(env, node->left, flag, return_type); /* Pull our parameters */ val2 = make_simple(env, node->right, INTERPRET_PARAMS, return_type); return build_function(env, val1, val2); case RETURN: val1 = make_simple(env, node->left, flag, return_type); /* Provide lookup for non-constants */ if (val1 && val1->value_type!=VT_INTEGR) { if (val1->value_type == VT_STRING) { val1 = get(env, val1->data.string_value); } else { val1 = get(env, val1->identifier); } if (!val1) fatal("Undeclared identifier"); } type_check_return(val1, return_type); append_code(make_return(val1)); return NULL; case ',': val1 = make_simple(env, node->left, flag, return_type); val2 = make_simple(env, node->right, flag, return_type); if (val1 && val2) { return join(val1, val2); } return NULL; case APPLY: /* FN Name */ val1 = make_simple(env, node->left, flag, return_type); /* Params */ val2 = make_simple(env, node->right, flag, return_type); /* Lookup function */ temp = search(env, to_string(val1), VT_FUNCTN, VT_ANY, 1); if (temp) { int fn_return_type; append_code(prepare_fn(val2)); append_code(push_params(env, val2)); /* If we can't typecheck, set a special UNDEFINED flag to say we can't */ /* typecheck. This can happen with function variables, we do not EASILY know the */ /* return type of the functions they are bound to until runtime. */ fn_return_type = UNDEFINED; if (temp->data.func) { fn_return_type = temp->data.func->return_type; } /* Temporary for result (if any) */ switch(fn_return_type) { case INT: temporary = generate_temporary(env, int_value(0)); break; case VOID: temporary = generate_temporary(env, NULL); break; case FUNCTION: temporary = generate_temporary(env, null_fn); break; default: temporary = generate_untypechecked_temporary(env); break; } append_code(make_fn_call(temporary, temp)); return temporary; } else { fatal("Cannot find function '%s'", to_string(val1)); } return NULL; case FUNCTION: case INT: case VOID: return int_value(type_of(node)); case ';': make_simple(env, node->left, flag, return_type); make_simple(env, node->right, flag, return_type); return NULL; default: fatal("Unrecognised node type"); return NULL; } }