Don't use zend_string for registerExtension- It may be freed

... before module shutdown
(In NTS builds of PHP 7 (e.g. 7.0.9) only)

Fixes https://github.com/phpv8/v8js/issues/247

This no longer returns getExtensions() in the order in which they were
registered.
This is slightly wasteful of memory - A custom hash function and
equality for `const char*` might be possible.

php_v8js_macros.h

@@ -27,6 +27,7 @@
 #include <list>
 #include <vector>
 #include <mutex>
+#include <unordered_map>
 
 #include <cmath>
 #ifndef isnan
@@ -77,7 +78,6 @@ extern "C" {
 #define ZEND_SLEEP_FUNC_NAME     "__sleep"
 #define ZEND_SET_STATE_FUNC_NAME "__set_state"
 
-
 /* Convert zval into V8 value */
 v8::Handle<v8::Value> zval_to_v8js(zval *, v8::Isolate * TSRMLS_DC);
 
@@ -97,8 +97,10 @@ void v8js_register_accessors(std::vector<v8js_accessor_ctx*> *accessor_list, v8:
 
 
 /* Forward declarations */
+struct v8js_jsext;
 struct v8js_timer_ctx;
 
+
 /* Module globals */
 ZEND_BEGIN_MODULE_GLOBALS(v8js)
   // Thread-local cache whether V8 has been initialized so far
@@ -145,7 +147,7 @@ struct _v8js_process_globals {
 	std::mutex lock;
 #endif
 
-	HashTable *extensions;
+	std::unordered_map<std::string, v8js_jsext*> extensions;
 
 	/* V8 command line flags */
 	char *v8_flags;

v8js.cc

@@ -163,11 +163,10 @@ static PHP_MSHUTDOWN_FUNCTION(v8js)
 		v8js_process_globals.v8_flags = NULL;
 	}
 
-	if (v8js_process_globals.extensions) {
+	for (auto& it: v8js_process_globals.extensions) {
-		zend_hash_destroy(v8js_process_globals.extensions);
+		v8js_jsext_free_storage(it.second);
-		free(v8js_process_globals.extensions);
-		v8js_process_globals.extensions = NULL;
 	}
+	v8js_process_globals.extensions.clear();
 
 	return SUCCESS;
 }

v8js_class.cc

@@ -18,6 +18,8 @@
 
 #include <functional>
 #include <algorithm>
+#include <string>
+#include <unordered_map>
 
 #include "php_v8js_macros.h"
 #include "v8js_v8.h"
@@ -62,11 +64,10 @@ int le_v8js_script;
 /* {{{ Extension container */
 struct v8js_jsext {
 	zend_bool auto_enable;
-	HashTable *deps_ht;
 	const char **deps;
 	int deps_count;
-	zend_string *name;
+	const char *name;
-	zend_string *source;
+	const char *source;
 	v8::Extension *extension;
 };
 /* }}} */
@@ -260,29 +261,19 @@ static void v8js_free_ext_strarr(const char **arr, int count) /* {{{ */
 }
 /* }}} */
 
-static void v8js_jsext_free_storage(v8js_jsext *jsext) /* {{{ */
+void v8js_jsext_free_storage(v8js_jsext *jsext) /* {{{ */
 {
-	if (jsext->deps_ht) {
-		zend_hash_destroy(jsext->deps_ht);
-		free(jsext->deps_ht);
-	}
 	if (jsext->deps) {
 		v8js_free_ext_strarr(jsext->deps, jsext->deps_count);
 	}
 	delete jsext->extension;
-	zend_string_release(jsext->name);
+	free((char*) jsext->name);
-	zend_string_release(jsext->source);
+	free((char*) jsext->source);
 
 	free(jsext);
 }
 /* }}} */
 
-static void v8js_jsext_dtor(zval *zv) /* {{{ */
-{
-	v8js_jsext_free_storage(reinterpret_cast<v8js_jsext *>(Z_PTR_P(zv)));
-}
-/* }}} */
-
 static int v8js_create_ext_strarr(const char ***retval, int count, HashTable *ht) /* {{{ */
 {
 	const char **exts = NULL;
@@ -897,13 +888,6 @@ static void v8js_persistent_zval_ctor(zval *p) /* {{{ */
 }
 /* }}} */
 
-static void v8js_persistent_zval_dtor(zval *p) /* {{{ */
-{
-	assert(Z_TYPE_P(p) == IS_STRING);
-	free(Z_STR_P(p));
-}
-/* }}} */
-
 static void v8js_script_free(v8js_script *res)
 {
 	efree(res->name);
@@ -925,18 +909,24 @@ static void v8js_script_dtor(zend_resource *rsrc) /* {{{ */
 }
 /* }}} */
 
+static char* zend_string_to_new_cstring(zend_string *string) { /* {{{ */
+	char* s = (char*) malloc(ZSTR_LEN(string) + 1);
+	memcpy(s, ZSTR_VAL(string), ZSTR_LEN(string));
+	s[ZSTR_LEN(string)] = '\0';
+	return s;
+}
+/* }}} */
+
 static int v8js_register_extension(zend_string *name, zend_string *source, zval *deps_arr, zend_bool auto_enable TSRMLS_DC) /* {{{ */
 {
 	v8js_jsext *jsext = NULL;
+	std::string key(ZSTR_VAL(name), ZSTR_LEN(name));
 
 #ifdef ZTS
 	v8js_process_globals.lock.lock();
 #endif
 
-	if (!v8js_process_globals.extensions) {
+	if (v8js_process_globals.extensions.find(key) != v8js_process_globals.extensions.end()) {
-		v8js_process_globals.extensions = (HashTable *) malloc(sizeof(HashTable));
-		zend_hash_init(v8js_process_globals.extensions, 1, NULL, v8js_jsext_dtor, 1);
-	} else if (zend_hash_exists(v8js_process_globals.extensions, name)) {
 #ifdef ZTS
 		v8js_process_globals.lock.unlock();
 #endif
@@ -959,24 +949,15 @@ static int v8js_register_extension(zend_string *name, zend_string *source, zval
 	}
 
 	jsext->auto_enable = auto_enable;
-	jsext->name = zend_string_dup(name, 1);
+	// TODO helper method
-	jsext->source = zend_string_dup(source, 1);
+	// Allocate character pointers, which need to outlive the allocated v8::Extension
+	jsext->name = zend_string_to_new_cstring(name);	
+	jsext->source = zend_string_to_new_cstring(source);
 
-	if (jsext->deps) {
+	// TODO: custom comparators
-		jsext->deps_ht = (HashTable *) malloc(sizeof(HashTable));
+	jsext->extension = new v8::Extension(jsext->name, jsext->source, jsext->deps_count, jsext->deps);
-		zend_hash_init(jsext->deps_ht, jsext->deps_count, NULL, v8js_persistent_zval_dtor, 1);
-		zend_hash_copy(jsext->deps_ht, Z_ARRVAL_P(deps_arr), v8js_persistent_zval_ctor);
-	}
 
-	jsext->extension = new v8::Extension(ZSTR_VAL(jsext->name), ZSTR_VAL(jsext->source), jsext->deps_count, jsext->deps);
+	v8js_process_globals.extensions.insert(std::pair<std::string, v8js_jsext*>(key, jsext));
-
-	if (!zend_hash_add_ptr(v8js_process_globals.extensions, jsext->name, jsext)) {
-		v8js_jsext_free_storage(jsext);
-#ifdef ZTS
-		v8js_process_globals.lock.unlock();
-#endif
-		return FAILURE;
-	}
 
 #ifdef ZTS
 	v8js_process_globals.lock.unlock();
@@ -1021,9 +1002,6 @@ static PHP_METHOD(V8Js, registerExtension)
 static PHP_METHOD(V8Js, getExtensions)
 {
 	v8js_jsext *jsext;
-	ulong index;
-	zend_string *key;
-	zval *val, ext;
 
 	if (zend_parse_parameters_none() == FAILURE) {
 		return;
@@ -1035,21 +1013,25 @@ static PHP_METHOD(V8Js, getExtensions)
 	v8js_process_globals.lock.lock();
 #endif
 
-	if (v8js_process_globals.extensions) {
+	if (v8js_process_globals.extensions.size() > 0) {
-		ZEND_HASH_FOREACH_KEY_VAL(v8js_process_globals.extensions, index, key, val) {
+		for (auto &it: v8js_process_globals.extensions) {
-			if (key) {
+			zval ext;
-				jsext = (v8js_jsext *) Z_PTR_P(val);
+			jsext = it.second;
 			array_init(&ext);
 			add_assoc_bool_ex(&ext, ZEND_STRL("auto_enable"), jsext->auto_enable);
-				if (jsext->deps_ht) {
+			if (jsext->deps) {
 				zval deps_arr;
-					array_init(&deps_arr);
+				int i;
-					zend_hash_copy(Z_ARRVAL_P(&deps_arr), jsext->deps_ht, (copy_ctor_func_t) zval_add_ref);
+				array_init_size(&deps_arr, jsext->deps_count);
+				for (i = 0; i < jsext->deps_count; i++) {
+					zval z;
+					ZVAL_STRING(&z, jsext->deps[i]);
+					zend_hash_next_index_insert(Z_ARRVAL_P(&deps_arr), &z);
+				}
 				add_assoc_zval_ex(&ext, ZEND_STRL("deps"), &deps_arr);
 			}
-				add_assoc_zval_ex(return_value, ZSTR_VAL(key), ZSTR_LEN(key), &ext);
+			add_assoc_zval_ex(return_value, it.first.data(), it.first.size(), &ext);
 		}
-		} ZEND_HASH_FOREACH_END();
 	}
 
 #ifdef ZTS

v8js_class.h

@@ -15,6 +15,8 @@
 #ifndef V8JS_CLASS_H
 #define V8JS_CLASS_H
 
+/* Forward declarations */
+struct v8js_jsext;
 
 /* Abbreviate long type names */
 typedef v8::Persistent<v8::FunctionTemplate, v8::CopyablePersistentTraits<v8::FunctionTemplate> > v8js_tmpl_t;
@@ -88,6 +90,8 @@ struct v8js_ctx {
 # define V8JS_TSRMLS_FETCH()
 #endif
 
+void v8js_jsext_free_storage(v8js_jsext *jsext);
+
 static inline struct v8js_ctx *v8js_ctx_fetch_object(zend_object *obj) {
 	return (struct v8js_ctx *)((char *)obj - XtOffsetOf(struct v8js_ctx, std));
 }