On Sun, 2004-02-15 at 16:09, Cristiano Duarte wrote:
> Hi Timm,
[...]
> IMHO, as you said, using an interface and letting the built-in class
> implement it is the best approach. But only instances of classes wich
> implement this interface should be throw or caught(language enforcement).
> With this enforcement, we can have a "catch all" for exceptions with
> less pain.
... and more flexibility for users like me who have their very own ideas
about a lot of thins:)
The following patch includes:
* An interface called "Throwable" which is implemented by the built-in
exception class. The interface is defined as following:
interface Throwable {
function getMessage();
function getFile();
function getLine();
}
* Checks on whether the exception thrown implements this interface
(rather than checking on subclasses of Exception), therefore
keeping the status quo of having a language enforcement on what
one can throw and "being clean" (which were the arguments for
this base class in the beginning, right?).
* The necessary changes to zend_catch_handler() which would only
check subclassing. Catch-all is implemented in the following way:
try {
// [...]
} catch (Throwable $e) {
print $e;
}
* A \n at the end of Exception::__toString() which does not require
one to write echo $e->__toString(), "\n" all the time.
Marcus, I do not think this adds any complexity. Especially not for the
user you are describing as "the average" and "wanting an easy exception
model" "the PHP way" "without any knowledge of interfaces":) For them,
this change is completely transparent (no changes need to be made).
In turn, it will make me and a couple of other people happy by leaving
us the freedom to decide whether we want (as Sterling put it)
all-your-base-our-belong-to-us-exceptions or design our own (and then
live with the fact that we can only accomplish 99% of the
built-in-exception's functionality).
- Timm
Index: Zend/zend_exceptions.c
===================================================================
RCS file: /repository/ZendEngine2/zend_exceptions.c,v
retrieving revision 1.58
diff -u -r1.58 zend_exceptions.c
--- Zend/zend_exceptions.c 12 Feb 2004 10:38:14 -0000 1.58
+++ Zend/zend_exceptions.c 15 Feb 2004 18:14:25 -0000
@@ -28,6 +28,7 @@
#include "zend_interfaces.h"
zend_class_entry *default_exception_ce;
+zend_class_entry *default_ithrowable_ce;
static zend_object_handlers default_exception_handlers;
ZEND_API void zend_throw_exception(zend_class_entry *exception_ce, char *message, long code TSRMLS_DC);
@@ -389,11 +390,11 @@
}
if (Z_STRLEN(message) > 0) {
- len = zend_spprintf(&str, 0, "exception '%s' with message '%s' in %s:%ld\nStack trace:\n%s",
+ len = zend_spprintf(&str, 0, "exception '%s' with message '%s' in %s:%ld\nStack trace:\n%s\n",
Z_OBJCE_P(getThis())->name, Z_STRVAL(message), Z_STRVAL(file), Z_LVAL(line),
(trace && Z_STRLEN_P(trace)) ? Z_STRVAL_P(trace) : "#0 {main}\n");
} else {
- len = zend_spprintf(&str, 0, "exception '%s' in %s:%ld\nStack trace:\n%s",
+ len = zend_spprintf(&str, 0, "exception '%s' in %s:%ld\nStack trace:\n%s\n",
Z_OBJCE_P(getThis())->name, Z_STRVAL(file), Z_LVAL(line),
(trace && Z_STRLEN_P(trace)) ? Z_STRVAL_P(trace) : "#0 {main}\n");
}
@@ -422,6 +423,14 @@
* And never try to change the state of exceptions and never implement anything
* that gives the user anything to accomplish this.
*/
+static zend_function_entry default_ithrowable_functions[] = {
+ ZEND_ABSTRACT_ME(exception, getMessage, NULL)
+ ZEND_ABSTRACT_ME(exception, getFile, NULL)
+ ZEND_ABSTRACT_ME(exception, getLine, NULL)
+ ZEND_ABSTRACT_ME(exception, __toString, NULL)
+ {NULL, NULL, NULL}
+};
+
static zend_function_entry default_exception_functions[] = {
ZEND_ME(exception, __clone, NULL, ZEND_ACC_PRIVATE|ZEND_ACC_FINAL)
ZEND_ME(exception, __construct, NULL, 0)
@@ -439,12 +448,23 @@
{
zend_class_entry ce;
- INIT_CLASS_ENTRY(ce, "exception", default_exception_functions);
+ INIT_CLASS_ENTRY(ce, "Throwable", default_ithrowable_functions);
+ default_ithrowable_ce = zend_register_internal_class(&ce TSRMLS_CC);
+ default_ithrowable_ce->ce_flags = ZEND_ACC_ABSTRACT | ZEND_ACC_INTERFACE;
+
+ INIT_CLASS_ENTRY(ce, "Exception", default_exception_functions);
default_exception_ce = zend_register_internal_class(&ce TSRMLS_CC);
default_exception_ce->create_object = zend_default_exception_new;
memcpy(&default_exception_handlers, zend_get_std_object_handlers(), sizeof(zend_object_handlers));
default_exception_handlers.clone_obj = NULL;
+ /* Implement the Throwable interface */
+ {
+ zend_uint num_interfaces = ++default_exception_ce->num_interfaces;
+ default_exception_ce->interfaces = (zend_class_entry **) realloc(default_exception_ce->interfaces, sizeof(zend_class_entry *) * num_interfaces);
+ default_exception_ce->interfaces[num_interfaces - 1] = default_ithrowable_ce;
+ }
+
zend_declare_property_string(default_exception_ce, "message", sizeof("message")-1, "", ZEND_ACC_PROTECTED TSRMLS_CC);
zend_declare_property_string(default_exception_ce, "string", sizeof("string")-1, "", ZEND_ACC_PRIVATE TSRMLS_CC);
zend_declare_property_long(default_exception_ce, "code", sizeof("code")-1, 0, ZEND_ACC_PROTECTED TSRMLS_CC);
@@ -470,8 +490,8 @@
MAKE_STD_ZVAL(ex);
if (exception_ce) {
- if (!instanceof_function(exception_ce, default_exception_ce TSRMLS_CC)) {
- zend_error(E_NOTICE, "Exceptions must be derived from exception");
+ if (!instanceof_function(exception_ce, default_ithrowable_ce TSRMLS_CC)) {
+ zend_error(E_NOTICE, "Exceptions must implement the Throwable interface");
exception_ce = default_exception_ce;
}
} else {
@@ -511,43 +531,44 @@
ZEND_API void zend_exception_error(zval *exception TSRMLS_DC)
{
zend_class_entry *ce_exception = Z_OBJCE_P(exception);
- if (instanceof_function(ce_exception, default_exception_ce TSRMLS_CC)) {
+ if (!instanceof_function(ce_exception, default_ithrowable_ce TSRMLS_CC)) {
+ zend_error(E_ERROR, "Uncaught exception '%s'", ce_exception->name);
+ } else {
zval *str, *file, *line;
zval *old_exception = EG(exception);
EG(exception) = NULL;
-
+
+ /* Call the methods __toString(), getFile() and getLine(), the Throwable
+ * interface ensures they exist.
+ */
zend_call_method_with_0_params(&exception, ce_exception, NULL, "__tostring", &str);
- if (!EG(exception)) {
- if (Z_TYPE_P(str) != IS_STRING) {
- zend_error(E_WARNING, "%s::__toString() must return a string", ce_exception->name);
- } else {
- zend_update_property_string(default_exception_ce, exception, "string", sizeof("string")-1, EG(exception) ? ce_exception->name : Z_STRVAL_P(str) TSRMLS_CC);
- }
- }
- zval_ptr_dtor(&str);
-
+ zend_call_method_with_0_params(&exception, ce_exception, NULL, "getfile", &file);
+ zend_call_method_with_0_params(&exception, ce_exception, NULL, "getline", &line);
+
+ /* The method call might throw an exception itself. There is no reproducing
+ * script to accomplish this behaviour, as throwing an exception from (e.g.)
+ * __toString() will result in a fatal error (Exception thrown without a
+ * stack frame in Unknown on line 0) but we'll handle this anyways
+ * just to be sure.
+ */
if (EG(exception)) {
- /* do the best we can to inform about the inner exception */
- if (instanceof_function(ce_exception, default_exception_ce TSRMLS_CC)) {
- file = zend_read_property(default_exception_ce, EG(exception), "file", sizeof("file")-1, 1 TSRMLS_CC);
- line = zend_read_property(default_exception_ce, EG(exception), "line", sizeof("line")-1, 1 TSRMLS_CC);
- } else {
- file = NULL;
- line = NULL;
- }
- zend_error_va(E_WARNING, file ? Z_STRVAL_P(file) : NULL, line ? Z_LVAL_P(line) : 0, "Uncaught %s in exception handling during call to %s::__tostring()", Z_OBJCE_P(EG(exception))->name, ce_exception->name);
+ zval_ptr_dtor(&str);
+ zval_ptr_dtor(&file);
+ zval_ptr_dtor(&line);
+
+ /* Restore the exception and bail */
+ EG(exception) = old_exception;
+ zend_error(E_ERROR, "Uncaught %s in exception handling for %s", Z_OBJCE_P(EG(exception))->name, ce_exception->name);
}
- str = zend_read_property(default_exception_ce, exception, "string", sizeof("string")-1, 1 TSRMLS_CC);
- file = zend_read_property(default_exception_ce, exception, "file", sizeof("file")-1, 1 TSRMLS_CC);
- line = zend_read_property(default_exception_ce, exception, "line", sizeof("line")-1, 1 TSRMLS_CC);
+ convert_to_string(str);
+ convert_to_string(file);
+ convert_to_long(line);
+ /* Restore the exception and bail */
EG(exception) = old_exception;
-
- zend_error_va(E_ERROR, Z_STRVAL_P(file), Z_LVAL_P(line), "Uncaught %s\n thrown", Z_STRVAL_P(str));
- } else {
- zend_error(E_ERROR, "Uncaught exception '%s'", ce_exception->name);
+ zend_error_va(E_ERROR, Z_STRVAL_P(file), Z_LVAL_P(line), "Uncaught %s thrown", Z_STRVAL_P(str));
}
}
@@ -562,8 +583,8 @@
exception_ce = Z_OBJCE_P(exception);
- if (!exception_ce || !instanceof_function(exception_ce, default_exception_ce TSRMLS_CC)) {
- zend_error(E_ERROR, "Exceptions must valid objects that are derived from class Exception");
+ if (!exception_ce || !instanceof_function(exception_ce, default_ithrowable_ce TSRMLS_CC)) {
+ zend_error(E_ERROR, "Exceptions must valid objects that implement the Throwable interface");
}
zend_throw_exception_internal(exception TSRMLS_CC);
}
Index: Zend/zend_execute.c
===================================================================
RCS file: /repository/ZendEngine2/zend_execute.c,v
retrieving revision 1.612
diff -u -r1.612 zend_execute.c
--- Zend/zend_execute.c 12 Feb 2004 15:23:06 -0000 1.612
+++ Zend/zend_execute.c 15 Feb 2004 18:14:26 -0000
@@ -2854,21 +2854,12 @@
int zend_catch_handler(ZEND_OPCODE_HANDLER_ARGS)
{
- zend_class_entry *ce;
-
/* Check whether an exception has been thrown, if not, jump over code */
if (EG(exception) == NULL) {
SET_OPCODE(&op_array->opcodes[opline->extended_value]);
return 0; /* CHECK_ME */
}
- ce = Z_OBJCE_P(EG(exception));
- if (ce != EX_T(opline->op1.u.var).class_entry) {
- while (ce->parent) {
- if (ce->parent == EX_T(opline->op1.u.var).class_entry) {
- goto exception_should_be_taken;
- }
- ce = ce->parent;
- }
+ if (!instanceof_function(Z_OBJCE_P(EG(exception)), EX_T(opline->op1.u.var).class_entry TSRMLS_CC)) {
if (opline->op1.u.EA.type) {
zend_throw_exception_internal(NULL TSRMLS_CC);
NEXT_OPCODE();
@@ -2877,7 +2868,6 @@
return 0; /* CHECK_ME */
}
-exception_should_be_taken:
zend_hash_update(EG(active_symbol_table), opline->op2.u.constant.value.str.val,
opline->op2.u.constant.value.str.len+1, &EG(exception), sizeof(zval *), (void **) NULL);
EG(exception) = NULL;
--
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