Rewrite watchpoints to be much more stable

This mainly involves a separate abstraction layer for elements (e.g. $a->b) and watchpoints (on pointer of the Bucket for example).
Also better comparison handling (value backup vs. page dumps).

It is not yet finished (there are sometimes false positives announced and names not yet perfect), but the functionality is working and not crashing as far as I have tested.
Future scope is also relative watchpoints, e.g. "w $this->val expression()" which does not have the symbol tables as basis, but the value (in this example: return value of expression()) as basis.

1 files changed, 97 insertions, 78 deletions

diff --git a/sapi/phpdbg/phpdbg.c b/sapi/phpdbg/phpdbg.c
index e4fa7a5874..0d0b4b41ca 100644
--- a/sapi/phpdbg/phpdbg.c
+++ b/sapi/phpdbg/phpdbg.c
@@ -75,6 +75,7 @@ PHP_INI_END()
 
 static zend_bool phpdbg_booted = 0;
 static zend_bool phpdbg_fully_started = 0;
+zend_bool use_mm_wrappers = 0;
 
 static inline void php_phpdbg_globals_ctor(zend_phpdbg_globals *pg) /* {{{ */
 {
@@ -189,79 +190,27 @@ static void php_phpdbg_destroy_registered(zval *data) /* {{{ */
 	destroy_zend_function(function);
 } /* }}} */
 
+static void php_phpdbg_destroy_file_source(zval *data) /* {{{ */
+{
+	phpdbg_file_source *source = (phpdbg_file_source *) Z_PTR_P(data);
+	destroy_op_array(&source->op_array);
+	if (source->buf) {
+		efree(source->buf);
+	}
+	efree(source);
+} /* }}} */
+
 
 static PHP_RINIT_FUNCTION(phpdbg) /* {{{ */
 {
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE], 8, NULL, php_phpdbg_destroy_bp_file, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_PENDING], 8, NULL, php_phpdbg_destroy_bp_file, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_SYM], 8, NULL, php_phpdbg_destroy_bp_symbol, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FUNCTION_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_OPLINE], 8, NULL, php_phpdbg_destroy_bp_opline, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_OPCODE], 8, NULL, php_phpdbg_destroy_bp_opcode, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_COND], 8, NULL, php_phpdbg_destroy_bp_condition, 0);
-	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_MAP], 8, NULL, NULL, 0);
-
-	zend_hash_init(&PHPDBG_G(seek), 8, NULL, NULL, 0);
-	zend_hash_init(&PHPDBG_G(registered), 8, NULL, php_phpdbg_destroy_registered, 0);
+	/* deactivate symbol table caching to have these properly destroyed upon stack leaving (especially important for watchpoints) */
+	EG(symtable_cache_limit) = EG(symtable_cache) - 1;
 
 	return SUCCESS;
 } /* }}} */
 
 static PHP_RSHUTDOWN_FUNCTION(phpdbg) /* {{{ */
 {
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_PENDING]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_SYM]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FUNCTION_OPLINE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD_OPLINE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_OPLINE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_OPLINE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_OPCODE]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_COND]);
-	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_MAP]);
-	zend_hash_destroy(&PHPDBG_G(file_sources));
-	zend_hash_destroy(&PHPDBG_G(seek));
-	zend_hash_destroy(&PHPDBG_G(registered));
-	zend_hash_destroy(&PHPDBG_G(watchpoints));
-	zend_llist_destroy(&PHPDBG_G(watchlist_mem));
-
-	if (PHPDBG_G(buffer)) {
-		free(PHPDBG_G(buffer));
-		PHPDBG_G(buffer) = NULL;
-	}
-
-	if (PHPDBG_G(exec)) {
-		efree(PHPDBG_G(exec));
-		PHPDBG_G(exec) = NULL;
-	}
-
-	if (PHPDBG_G(oplog)) {
-		fclose(PHPDBG_G(oplog));
-		PHPDBG_G(oplog) = NULL;
-	}
-
-	if (PHPDBG_G(ops)) {
-		destroy_op_array(PHPDBG_G(ops));
-		efree(PHPDBG_G(ops));
-		PHPDBG_G(ops) = NULL;
-	}
-
-	if (PHPDBG_G(oplog_list)) {
-		phpdbg_oplog_list *cur = PHPDBG_G(oplog_list);
-		do {
-			phpdbg_oplog_list *prev = cur->prev;
-			efree(cur);
-			cur = prev;
-		} while (cur != NULL);
-
-		zend_arena_destroy(PHPDBG_G(oplog_arena));
-		PHPDBG_G(oplog_list) = NULL;
-	}
-
 	return SUCCESS;
 } /* }}} */
 
@@ -845,8 +794,86 @@ static void php_sapi_phpdbg_log_message(char *message, int syslog_type_int) /* {
 }
 /* }}} */
 
+static int php_sapi_phpdbg_activate(void) /* {{{ */
+{
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE], 8, NULL, php_phpdbg_destroy_bp_file, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_PENDING], 8, NULL, php_phpdbg_destroy_bp_file, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_SYM], 8, NULL, php_phpdbg_destroy_bp_symbol, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FUNCTION_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_OPLINE], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_OPLINE], 8, NULL, php_phpdbg_destroy_bp_opline, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_OPCODE], 8, NULL, php_phpdbg_destroy_bp_opcode, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD], 8, NULL, php_phpdbg_destroy_bp_methods, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_COND], 8, NULL, php_phpdbg_destroy_bp_condition, 0);
+	zend_hash_init(&PHPDBG_G(bp)[PHPDBG_BREAK_MAP], 8, NULL, NULL, 0);
+
+	zend_hash_init(&PHPDBG_G(seek), 8, NULL, NULL, 0);
+	zend_hash_init(&PHPDBG_G(registered), 8, NULL, php_phpdbg_destroy_registered, 0);
+
+	zend_hash_init(&PHPDBG_G(file_sources), 0, NULL, php_phpdbg_destroy_file_source, 0);
+	phpdbg_setup_watchpoints();
+
+	return SUCCESS;
+}
+
 static int php_sapi_phpdbg_deactivate(void) /* {{{ */
 {
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_PENDING]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_SYM]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FUNCTION_OPLINE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD_OPLINE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_FILE_OPLINE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_OPLINE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_OPCODE]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_METHOD]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_COND]);
+	zend_hash_destroy(&PHPDBG_G(bp)[PHPDBG_BREAK_MAP]);
+	zend_hash_destroy(&PHPDBG_G(file_sources));
+	zend_hash_destroy(&PHPDBG_G(seek));
+	zend_hash_destroy(&PHPDBG_G(registered));
+	phpdbg_destroy_watchpoints();
+
+	/* hack to restore mm_heap->use_custom_heap in order to receive memory leak info */
+	if (use_mm_wrappers) {
+		/* ASSUMING that mm_heap->use_custom_heap is the first element of the struct ... */
+		*(int *) zend_mm_get_heap() = 0;
+	}
+
+	if (PHPDBG_G(buffer)) {
+		free(PHPDBG_G(buffer));
+		PHPDBG_G(buffer) = NULL;
+	}
+
+	if (PHPDBG_G(exec)) {
+		efree(PHPDBG_G(exec));
+		PHPDBG_G(exec) = NULL;
+	}
+
+	if (PHPDBG_G(oplog)) {
+		fclose(PHPDBG_G(oplog));
+		PHPDBG_G(oplog) = NULL;
+	}
+
+	if (PHPDBG_G(ops)) {
+		destroy_op_array(PHPDBG_G(ops));
+		efree(PHPDBG_G(ops));
+		PHPDBG_G(ops) = NULL;
+	}
+
+	if (PHPDBG_G(oplog_list)) {
+		phpdbg_oplog_list *cur = PHPDBG_G(oplog_list);
+		do {
+			phpdbg_oplog_list *prev = cur->prev;
+			efree(cur);
+			cur = prev;
+		} while (cur != NULL);
+
+		zend_arena_destroy(PHPDBG_G(oplog_arena));
+		PHPDBG_G(oplog_list) = NULL;
+	}
+
 	fflush(stdout);
 	if (SG(request_info).argv0) {
 		free(SG(request_info).argv0);
@@ -994,7 +1021,7 @@ static sapi_module_struct phpdbg_sapi_module = {
 	php_sapi_phpdbg_module_startup, /* startup */
 	php_module_shutdown_wrapper,    /* shutdown */
 
-	NULL,                           /* activate */
+	php_sapi_phpdbg_activate,       /* activate */
 	php_sapi_phpdbg_deactivate,     /* deactivate */
 
 	php_sapi_phpdbg_ub_write,       /* unbuffered write */
@@ -1236,11 +1263,11 @@ void phpdbg_signal_handler(int sig, siginfo_t *info, void *context) /* {{{ */
 	switch (sig) {
 		case SIGBUS:
 		case SIGSEGV:
-			if (PHPDBG_G(sigsegv_bailout)) {
-				LONGJMP(*PHPDBG_G(sigsegv_bailout), FAILURE);
-			}
 			is_handled = phpdbg_watchpoint_segfault_handler(info, context);
 			if (is_handled == FAILURE) {
+				if (PHPDBG_G(sigsegv_bailout)) {
+					LONGJMP(*PHPDBG_G(sigsegv_bailout), FAILURE);
+				}
 				zend_sigaction(sig, &PHPDBG_G(old_sigsegv_signal), NULL);
 			}
 			break;
@@ -1308,7 +1335,6 @@ int main(int argc, char **argv) /* {{{ */
 	FILE* stream = NULL;
 	char *print_opline_func;
 	zend_bool ext_stmt = 0;
-	zend_bool use_mm_wrappers = 0;
 	zend_bool is_exit;
 	int exit_status;
 
@@ -1635,8 +1661,6 @@ phpdbg_main:
 
 		use_mm_wrappers = !_malloc && !_realloc && !_free;
 
-		phpdbg_init_list();
-
 		PHPDBG_G(original_free_function) = _free;
 		_free = phpdbg_watch_efree;
 
@@ -1650,14 +1674,14 @@ phpdbg_main:
 			zend_mm_set_custom_handlers(mm_heap, _malloc, _free, _realloc);
 		}
 
-		phpdbg_setup_watchpoints();
-
 #if defined(ZEND_SIGNALS) && !defined(_WIN32)
 		zend_try {
 			zend_signal_activate();
 		} zend_end_try();
 #endif
 
+		phpdbg_init_list();
+
 		PHPDBG_G(sapi_name_ptr) = sapi_name;
 
 		if (exec) { /* set execution context */
@@ -1976,11 +2000,6 @@ phpdbg_out:
 			}
 		}
 
-		/* hack to restore mm_heap->use_custom_heap in order to receive memory leak info */
-		if (use_mm_wrappers) {
-			/* ASSUMING that mm_heap->use_custom_heap is the first element of the struct ... */
-			*(int *) mm_heap = 0;
-		}
 		zend_try {
 			php_request_shutdown(NULL);
 		} zend_end_try();