Replace remaining PHP errors with PHP exceptions

`SWIG_ErrorCode()`, `SWIG_ErrorMsg()`, `SWIG_FAIL()` and `goto thrown;`
are no longer supported (these are really all internal implementation
details and none are documented aside from brief mentions in CHANGES
for the first three).  I wasn't able to find any uses at least in FOSS
code via code search tools.

If you are using these:

Use `SWIG_PHP_Error(code,msg);` instead of `SWIG_ErrorCode(code);
SWIG_ErrorMsg(msg);` (which will throw a PHP exception in SWIG >= 4.1
and do the same as the individual calls in older SWIG).

`SWIG_FAIL();` and `goto thrown;` can typically be replaced with
`SWIG_fail;`.  This will probably also work with older SWIG, but
please test with your wrappers if this is important to you.

Fixes #2014

CHANGES.current

@@ -8,11 +8,33 @@ Version 4.1.0 (in progress)
 ===========================
 
 2021-05-04: olly
-	    [PHP] #2014 Throw exceptions instead of using errors
+	    [PHP] #2014 Throw PHP exceptions instead of using PHP errors
 
-	    Parameter type errors and some other cases in SWIG-generated wrappers
+	    PHP exceptions can be caught and handled if desired, but if they
-	    now throw a PHP exception, which is how PHP's native parameter handling
+	    aren't caught then PHP exits in much the same way as it does for a
-	    deals with similar situations.
+	    PHP error.
+
+	    In particular this means parameter type errors and some other cases
+	    in SWIG-generated wrappers now throw a PHP exception, which matches
+	    how PHP's native parameter handling deals with similar situations.
+
+	    `SWIG_ErrorCode()`, `SWIG_ErrorMsg()`, `SWIG_FAIL()` and `goto thrown;`
+	    are no longer supported (these are really all internal implementation
+	    details and none are documented aside from brief mentions in CHANGES
+	    for the first three).  I wasn't able to find any uses in user interface
+	    files at least in FOSS code via code search tools.
+
+	    If you are using these:
+
+	    Use `SWIG_PHP_Error(code,msg);` instead of `SWIG_ErrorCode(code);
+	    SWIG_ErrorMsg(msg);` (which will throw a PHP exception in SWIG >= 4.1
+	    and do the same as the individual calls in older SWIG).
+
+	    `SWIG_FAIL();` and `goto thrown;` can typically be replaced with
+	    `SWIG_fail;`.  This will probably also work with older SWIG, but
+	    please test with your wrappers if this is important to you.
+
+	    *** POTENTIAL INCOMPATIBILITY ***
 
 2021-05-17: adr26
             [Python] #1985 Fix memory leaks:

Lib/exception.i

@@ -25,7 +25,7 @@
     code == SWIG_DivisionByZero ? zend_ce_division_by_zero_error : \
     code == SWIG_SyntaxError ? zend_ce_parse_error : \
     code == SWIG_OverflowError ? zend_ce_arithmetic_error : \
-    NULL, msg, code); goto thrown; } while (0)
+    NULL, msg, code); SWIG_fail; } while (0)
 %}
 #endif
 

Lib/php/director.swg

@@ -137,8 +137,8 @@ namespace Swig {
         swig_msg += " ";
         swig_msg += msg;
       }
-      SWIG_ErrorCode() = code;
+      // Don't replace an already active PHP exception.
-      SWIG_ErrorMsg() = swig_msg.c_str();
+      if (!EG(exception)) zend_throw_exception(NULL, swig_msg.c_str(), code);
     }
 
     virtual ~DirectorException() throw() {

Lib/php/php.swg

@@ -96,7 +96,7 @@
 %{
   if (SWIG_ConvertPtr($input, (void **) &tmp, $&1_descriptor, 0) < 0 || tmp == NULL) {
     zend_type_error("Expected $&1_descriptor for argument $argnum of $symname");
-    goto thrown;
+    SWIG_fail;
   }
   $result = *tmp;
 %}
@@ -115,7 +115,7 @@
 %{
   if (SWIG_ConvertPtrAndOwn($input, (void **)&$result, $1_descriptor, SWIG_POINTER_DISOWN, &own) < 0) {
     zend_type_error("Expected $1_descriptor for argument $argnum of $symname");
-    goto thrown;
+    SWIG_fail;
   }
   swig_acquire_ownership_obj((void*)$result, own);
 %}
@@ -134,7 +134,7 @@
 %{
   if (SWIG_ConvertPtr($input, (void **) &tmp, $1_descriptor, 0) < 0 || tmp == NULL) {
     zend_type_error("Expected $1_descriptor for argument $argnum of $symname");
-    goto thrown;
+    SWIG_fail;
   }
   $result = tmp;
 %}

Lib/php/phprun.swg

@@ -58,15 +58,12 @@ static zend_always_inline void *zend_object_alloc(size_t obj_size, zend_class_en
 
 #define SWIG_fail goto fail
 
-// If there's an active PHP exception, just return so it can propagate.
-#define SWIG_FAIL() do { if (!EG(exception)) zend_error_noreturn(SWIG_ErrorCode(), "%s", SWIG_ErrorMsg()); goto thrown; } while (0)
-
 static const char *default_error_msg = "Unknown error occurred";
 static int default_error_code = E_ERROR;
 
 #define SWIG_PHP_Arg_Error_Msg(argnum,extramsg) "Error in argument " #argnum " "#extramsg
 
-#define SWIG_PHP_Error(code,msg) do { SWIG_ErrorCode() = code; SWIG_ErrorMsg() = msg; SWIG_fail; } while (0)
+#define SWIG_PHP_Error(code,msg) do { zend_throw_exception(NULL, msg, code); SWIG_fail; } while (0)
 
 #define SWIG_contract_assert(expr,msg) \
   do { if (!(expr)) zend_printf("Contract Assert Failed %s\n", msg); } while (0)
@@ -102,7 +99,7 @@ SWIG_SetPointerZval(zval *z, void *ptr, swig_type_info *type, int newobject) {
   }
 
   if (!type->clientdata) {
-    zend_error(E_ERROR, "Type: %s not registered with zend", type->name);
+    zend_type_error("Type: %s not registered with zend", type->name);
     return;
   }
 

Lib/php/typemaps.i

@@ -277,7 +277,7 @@ INT_TYPEMAP(unsigned long long);
     if (!(Z_ISREF($input) && Z_ISNULL_P(Z_REFVAL($input)))) {
       /* wasn't a pre/ref/thing, OR anything like an int thing */
       zend_type_error("Expected reference or NULL for argument $arg of $symname");
-      SWIG_FAIL;
+      return;
     }
   }
   force=0;

Source/Modules/php.cxx

@@ -359,29 +359,7 @@ public:
 
     /* Initialize the rest of the module */
 
-    Printf(s_oinit, "  ZEND_INIT_MODULE_GLOBALS(%s, %s_init_globals, NULL);\n", module, module);
-
     /* start the header section */
-    Printf(s_header, "ZEND_BEGIN_MODULE_GLOBALS(%s)\n", module);
-    Printf(s_header, "const char *error_msg;\n");
-    Printf(s_header, "int error_code;\n");
-    Printf(s_header, "ZEND_END_MODULE_GLOBALS(%s)\n", module);
-    Printf(s_header, "ZEND_DECLARE_MODULE_GLOBALS(%s)\n", module);
-    Printf(s_header, "#define SWIG_ErrorMsg() ZEND_MODULE_GLOBALS_ACCESSOR(%s, error_msg)\n", module);
-    Printf(s_header, "#define SWIG_ErrorCode() ZEND_MODULE_GLOBALS_ACCESSOR(%s, error_code)\n", module);
-
-    Printf(s_header, "static void %s_init_globals(zend_%s_globals *globals ) {\n", module, module);
-    Printf(s_header, "  globals->error_msg = default_error_msg;\n");
-    Printf(s_header, "  globals->error_code = default_error_code;\n");
-    Printf(s_header, "}\n");
-
-    Printf(s_header, "static void SWIG_ResetError(void) {\n");
-    Printf(s_header, "  SWIG_ErrorMsg() = default_error_msg;\n");
-    Printf(s_header, "  SWIG_ErrorCode() = default_error_code;\n");
-    Printf(s_header, "}\n");
-
-    Append(s_header, "\n");
-
     Printf(s_header, "#define SWIG_name  \"%s\"\n", module);
     Printf(s_header, "#ifdef __cplusplus\n");
     Printf(s_header, "extern \"C\" {\n");
@@ -831,7 +809,7 @@ public:
     Printv(f->code, dispatch, "\n", NIL);
 
     Printf(f->code, "zend_throw_exception(zend_ce_type_error, \"No matching function for overloaded '%s'\", 0);\n", symname);
-    Printv(f->code, "thrown:\n", NIL);
+    Printv(f->code, "fail:\n", NIL);
     Printv(f->code, "return;\n", NIL);
     Printv(f->code, "}\n", NIL);
     Wrapper_print(f, s_wrappers);
@@ -947,12 +925,8 @@ public:
       Printf(f->code, "add_property_zval_ex(ZEND_THIS, ZSTR_VAL(arg2), ZSTR_LEN(arg2), &args[1]);\n}\n");
     }
 
-    Printf(f->code, "thrown:\n");
-    Printf(f->code, "return;\n");
-
-    /* Error handling code */
     Printf(f->code, "fail:\n");
-    Append(f->code, "SWIG_FAIL();\n");
+    Printf(f->code, "return;\n");
     Printf(f->code, "}\n\n\n");
 
 
@@ -984,12 +958,8 @@ public:
       Printf(f->code, "RETVAL_NULL();\n}\n");
     }
 
-    Printf(f->code, "thrown:\n");
-    Printf(f->code, "return;\n");
-
-    /* Error handling code */
     Printf(f->code, "fail:\n");
-    Append(f->code, "SWIG_FAIL();\n");
+    Printf(f->code, "return;\n");
     Printf(f->code, "}\n\n\n");
 
 
@@ -1020,12 +990,8 @@ public:
       Printf(f->code, "RETVAL_FALSE;\n}\n");
     }
 
-    Printf(f->code, "thrown:\n");
-    Printf(f->code, "return;\n");
-
-    /* Error handling code */
     Printf(f->code, "fail:\n");
-    Append(f->code, "SWIG_FAIL();\n");
+    Printf(f->code, "return;\n");
     Printf(f->code, "}\n\n\n");
 
     Wrapper_print(f, s_wrappers);
@@ -1243,8 +1209,6 @@ public:
 
     // NOTE: possible we ignore this_ptr as a param for native constructor
 
-    Printf(f->code, "SWIG_ResetError();\n");
-
     if (numopt > 0) {		// membervariable wrappers do not have optional args
       Wrapper_add_local(f, "arg_count", "int arg_count");
       Printf(f->code, "arg_count = ZEND_NUM_ARGS();\n");
@@ -1420,14 +1384,9 @@ public:
     }
 
     if (!static_setter) {
-      Printf(f->code, "thrown:\n");
-      Printf(f->code, "return;\n");
-
-      /* Error handling code */
       Printf(f->code, "fail:\n");
       Printv(f->code, cleanup, NIL);
-      Append(f->code, "SWIG_FAIL();\n");
+      Printf(f->code, "return;\n");
-
       Printf(f->code, "}\n");
     }
 
@@ -2186,7 +2145,7 @@ public:
       Delete(outarg);
     }
 
-    Append(w->code, "thrown:\n");
+    Append(w->code, "fail: ;\n");
     if (!is_void) {
       if (!(ignored_method && !pure_virtual)) {
 	String *rettype = SwigType_str(returntype, 0);
@@ -2197,12 +2156,7 @@ public:
 	}
 	Delete(rettype);
       }
-    } else {
-      Append(w->code, "return;\n");
     }
-
-    Append(w->code, "fail:\n");
-    Append(w->code, "SWIG_FAIL();\n");
     Append(w->code, "}\n");
 
     // We expose protected methods via an extra public inline method which makes a straight call to the wrapped class' method