From fd2a109f86d18b93d29153c2ddfa605651c7df05 Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikic@php.net>
Date: Sat, 19 May 2012 18:49:27 +0200
Subject: [PATCH] Add error if yield is used outside a generator

The yield statement can only be used in generator functions, which are
marked with an asterix.
---
 .../generators/yield_in_normal_function_error.phpt   | 12 ++++++++++++
 .../generators/yield_outside_function_error.phpt     | 10 ++++++++++
 Zend/zend_compile.c                                  |  6 +++++-
 3 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 Zend/tests/generators/yield_in_normal_function_error.phpt
 create mode 100644 Zend/tests/generators/yield_outside_function_error.phpt

diff --git a/Zend/tests/generators/yield_in_normal_function_error.phpt b/Zend/tests/generators/yield_in_normal_function_error.phpt
new file mode 100644
index 00000000000..802510d29cc
--- /dev/null
+++ b/Zend/tests/generators/yield_in_normal_function_error.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Yield cannot be used in normal (non-generator) functions
+--FILE--
+<?php
+
+function foo() {
+    yield "Test";
+}
+
+?>
+--EXPECTF--
+Fatal error: The "yield" statement can only be used inside a generator function in %s on line %d
diff --git a/Zend/tests/generators/yield_outside_function_error.phpt b/Zend/tests/generators/yield_outside_function_error.phpt
new file mode 100644
index 00000000000..fd7169d5f2e
--- /dev/null
+++ b/Zend/tests/generators/yield_outside_function_error.phpt
@@ -0,0 +1,10 @@
+--TEST--
+Yield cannot be used outside of functions
+--FILE--
+<?php
+
+yield "Test";
+
+?>
+--EXPECTF--
+Fatal error: The "yield" statement can only be used inside a generator function in %s on line %d
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 0d3ea109bff..d2b3536788e 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -2660,7 +2660,11 @@ void zend_do_return(znode *expr, int do_end_vparse TSRMLS_DC) /* {{{ */
 
 void zend_do_yield(znode *expr TSRMLS_DC) /* {{{ */
 {
-    /* do nothing for now */
+	if ((CG(active_op_array)->fn_flags & ZEND_ACC_GENERATOR) == 0) {
+		zend_error(E_COMPILE_ERROR, "The \"yield\" statement can only be used inside a generator function");
+	}
+
+	/* do nothing for now */
 }
 /* }}} */