Zend/JIT: fix undefined function suggestion under opcache JIT

The JIT compiler had its own hand-written stub for raising "Call to
undefined function" errors that bypassed the new Levenshtein
suggestion logic, since it duplicated the error message instead of
reusing the interpreter's helper. Extract the shared logic into
zend_undefined_function_error() and call it from both the VM helper
and the JIT stub.

Author: jorgsowa

Zend/zend_execute.c

@@ -2607,6 +2607,19 @@ ZEND_API zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_undefined_method(co
 	}
 }
 
+/* function_name and function_name[1] (the lowercased key) are adjacent RT_CONSTANT literals;
+ * for INIT_NS_FCALL_BY_NAME with a namespace prefix, function_name[2] is the global fallback */
+ZEND_API zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_undefined_function_error(zval *function_name)
+{
+	zend_string *lc_key = Z_STR_P(function_name + 1);
+	zend_string *suggestion = zend_find_similar_function(ZSTR_VAL(lc_key), ZSTR_LEN(lc_key));
+	if (suggestion) {
+		zend_throw_error(NULL, "Call to undefined function %s() (did you mean %s()?)", Z_STRVAL_P(function_name), ZSTR_VAL(suggestion));
+	} else {
+		zend_throw_error(NULL, "Call to undefined function %s()", Z_STRVAL_P(function_name));
+	}
+}
+
 static zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_invalid_method_call(const zval *object, const zval *function_name)
 {
 	zend_throw_error(NULL, "Call to a member function %s() on %s",

Zend/zend_execute.h

@@ -513,6 +513,7 @@ ZEND_API ZEND_ATTRIBUTE_DEPRECATED HashTable *zend_unfinished_execution_gc(zend_
 ZEND_API HashTable *zend_unfinished_execution_gc_ex(zend_execute_data *execute_data, zend_execute_data *call, zend_get_gc_buffer *gc_buffer, bool suspended_by_yield);
 ZEND_API zval* ZEND_FASTCALL zend_fetch_static_property(zend_execute_data *ex, int fetch_type);
 ZEND_API zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_undefined_method(const zend_class_entry *ce, const zend_string *method);
+ZEND_API zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_undefined_function_error(zval *function_name);
 ZEND_API zend_never_inline ZEND_COLD void ZEND_FASTCALL zend_non_static_method_call(const zend_function *fbc);
 
 ZEND_API void zend_frameless_observed_call(zend_execute_data *execute_data);

Zend/zend_vm_def.h

@@ -1000,14 +1000,7 @@ ZEND_VM_COLD_HELPER(zend_undefined_function_helper, ANY, ANY)
 
 	SAVE_OPLINE();
 	function_name = RT_CONSTANT(opline, opline->op2);
-	/* For INIT_NS_FCALL_BY_NAME with a namespace prefix, op2+2 is the global fallback */
-	zend_string *lc_key = Z_STR_P(function_name + 1);
-	zend_string *suggestion = zend_find_similar_function(ZSTR_VAL(lc_key), ZSTR_LEN(lc_key));
-	if (suggestion) {
-		zend_throw_error(NULL, "Call to undefined function %s() (did you mean %s()?)", Z_STRVAL_P(function_name), ZSTR_VAL(suggestion));
-	} else {
-		zend_throw_error(NULL, "Call to undefined function %s()", Z_STRVAL_P(function_name));
-	}
+	zend_undefined_function_error(function_name);
 	HANDLE_EXCEPTION();
 }
 

Zend/zend_vm_execute.h

@@ -2168,21 +2168,13 @@ static int zend_jit_undefined_function_stub(zend_jit_ctx *jit)
 {
 	// JIT: load EX(opline)
 	ir_ref ref = ir_LOAD_A(jit_FP(jit));
-	ir_ref arg3 = ir_LOAD_U32(ir_ADD_OFFSET(ref, offsetof(zend_op, op2.constant)));
+	ir_ref arg1 = ir_LOAD_U32(ir_ADD_OFFSET(ref, offsetof(zend_op, op2.constant)));
 
 	if (sizeof(void*) == 8) {
-		arg3 = ir_LOAD_A(ir_ADD_A(ref, ir_SEXT_A(arg3)));
-	} else {
-		arg3 = ir_LOAD_A(arg3);
+		arg1 = ir_ADD_A(ref, ir_SEXT_A(arg1));
 	}
-	arg3 = ir_ADD_OFFSET(arg3, offsetof(zend_string, val));
 
-	ir_CALL_3(IR_VOID,
-		ir_CONST_FUNC_PROTO(zend_throw_error,
-			ir_proto_2(&jit->ctx, IR_VARARG_FUNC, IR_VOID, IR_ADDR, IR_ADDR)),
-		IR_NULL,
-		ir_CONST_ADDR("Call to undefined function %s()"),
-		arg3);
+	ir_CALL_1(IR_VOID, ir_CONST_FC_FUNC(zend_undefined_function_error), arg1);
 
 	ir_IJMP(jit_STUB_ADDR(jit, jit_stub_exception_handler));