From 0cf4ab66e9927e101a51dd9fa9adc6c8dc56b5e7 Mon Sep 17 00:00:00 2001

From: Petr Machata <pmachata@redhat.com>

Date: Thu, 21 Nov 2013 20:25:53 +0100

Subject: [PATCH] Consider exec and exit events an end of outstanding calls

- This cleans up a lot of stuff.  The actual substance is addition of

  account_current_callstack in handle_event.c (which however uses

  those cleaned-up interfaces).

- trace-exec.exp was extended to check that the exec syscall can be

  seen in -c output.  That's one of the symptoms of what this fixes.

---

 Makefile.am                           |    8 +-

 common.h                              |    2 -

 forward.h                             |    1 +

 handle_event.c                        |  225 ++++++++++++++++++++-------------

 libltrace.c                           |    5 +-

 options.h                             |    8 +-

 output.c                              |   86 +++----------

 output.h                              |    5 +-

 proc.h                                |    2 +-

 summary.c                             |   89 +++++++++++++-

 summary.h                             |   35 +++++

 testsuite/ltrace.minor/trace-exec.exp |   16 ++-

 12 files changed, 299 insertions(+), 183 deletions(-)

 create mode 100644 summary.h

diff --git a/Makefile.am b/Makefile.am

index d711aec..efcf18a 100644

--- a/Makefile.am

+++ b/Makefile.am

@@ -54,10 +54,10 @@ ltrace_LDADD = \

 noinst_HEADERS = bits.h backend.h breakpoint.h common.h debug.h		\

 	defs.h demangle.h dict.h forward.h ltrace-elf.h ltrace.h	\

-	options.h output.h proc.h read_config_file.h library.h		\

-	filter.h glob.h vect.h type.h value.h value_dict.h callback.h	\

-	expr.h fetch.h vect.h param.h printf.h zero.h lens.h		\

-	lens_default.h lens_enum.h memstream.h prototype.h

+	options.h output.h proc.h read_config_file.h summary.h		\

+	library.h filter.h glob.h vect.h type.h value.h value_dict.h	\

+	callback.h expr.h fetch.h vect.h param.h printf.h zero.h	\

+	lens.h lens_default.h lens_enum.h memstream.h prototype.h

 dist_man1_MANS = ltrace.1

 dist_man5_MANS = ltrace.conf.5

diff --git a/common.h b/common.h

index a53c5db..7259ba4 100644

--- a/common.h

+++ b/common.h

@@ -54,8 +54,6 @@ extern void handle_event(Event * event);

 extern pid_t execute_program(const char * command, char ** argv);

-extern void show_summary(void);

-

 struct breakpoint;

 struct library_symbol;

diff --git a/forward.h b/forward.h

index 8641213..58d8f05 100644

--- a/forward.h

+++ b/forward.h

@@ -34,6 +34,7 @@ struct param_enum;

 struct process;

 struct protolib;

 struct prototype;

+struct timedelta;

 struct value;

 struct value_dict;

 struct vect;

diff --git a/handle_event.c b/handle_event.c

index 9ed62a2..6fa7e98 100644

--- a/handle_event.c

+++ b/handle_event.c

@@ -32,7 +32,6 @@

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

-#include <sys/time.h>

 #include <stdbool.h>

 #include "backend.h"

@@ -41,8 +40,9 @@

 #include "fetch.h"

 #include "library.h"

 #include "proc.h"

-#include "value_dict.h"

 #include "prototype.h"

+#include "summary.h"

+#include "value_dict.h"

 static void handle_signal(Event *event);

 static void handle_exit(Event *event);

@@ -419,32 +419,11 @@ handle_signal(Event *event) {

 	continue_after_signal(event->proc->pid, event->e_un.signum);

 }

-static void

-handle_exit(Event *event) {

-	debug(DEBUG_FUNCTION, "handle_exit(pid=%d, status=%d)", event->proc->pid, event->e_un.ret_val);

-	if (event->proc->state != STATE_IGNORED) {

-		output_line(event->proc, "+++ exited (status %d) +++",

-				event->e_un.ret_val);

-	}

-	remove_process(event->proc);

-}

-

-static void

-handle_exit_signal(Event *event) {

-	debug(DEBUG_FUNCTION, "handle_exit_signal(pid=%d, signum=%d)", event->proc->pid, event->e_un.signum);

-	if (event->proc->state != STATE_IGNORED) {

-		output_line(event->proc, "+++ killed by %s +++",

-				shortsignal(event->proc, event->e_un.signum));

-	}

-	remove_process(event->proc);

-}

-

-static void

-output_syscall(struct process *proc, const char *name, enum tof tof,

-	       void (*output)(enum tof, struct process *,

-			      struct library_symbol *))

+static int

+init_syscall_symbol(struct library_symbol *libsym, const char *name)

 {

 	static struct library syscall_lib;

+

 	if (syscall_lib.protolib == NULL) {

 		struct protolib *protolib

 			= protolib_cache_load(&g_protocache, "syscalls", 0, 1);

@@ -475,10 +454,91 @@ output_syscall(struct process *proc, const char *name, enum tof tof,

 		syscall_lib.protolib = protolib;

 	}

+	if (library_symbol_init(libsym, 0, name, 0, LS_TOPLT_NONE) < 0)

+		return -1;

+

+	libsym->lib = &syscall_lib;

+	return 0;

+}

+

+/* Account the unfinished functions on the call stack.  */

+static void

+account_current_callstack(struct process *proc)

+{

+	if (! options.summary)

+		return;

+

+	struct timedelta spent[proc->callstack_depth];

+

+	size_t i;

+	for (i = 0; i < proc->callstack_depth; ++i) {

+		struct callstack_element *elem = &proc->callstack[i];

+		spent[i] = calc_time_spent(elem->enter_time);

+	}

+

+	for (i = 0; i < proc->callstack_depth; ++i) {

+		struct callstack_element *elem = &proc->callstack[i];

+		struct library_symbol syscall, *libsym = NULL;

+		if (elem->is_syscall) {

+			const char *name = sysname(proc, elem->c_un.syscall);

+			if (init_syscall_symbol(&syscall, name) >= 0)

+				libsym = &syscall;

+

+		} else {

+			libsym = elem->c_un.libfunc;

+		}

+

+		if (libsym != NULL) {

+			summary_account_call(libsym, spent[i]);

+

+			if (elem->is_syscall)

+				library_symbol_destroy(&syscall);

+		}

+	}

+}

+

+static void

+handle_exit(Event *event) {

+	debug(DEBUG_FUNCTION, "handle_exit(pid=%d, status=%d)", event->proc->pid, event->e_un.ret_val);

+	if (event->proc->state != STATE_IGNORED) {

+		output_line(event->proc, "+++ exited (status %d) +++",

+				event->e_un.ret_val);

+	}

+

+	account_current_callstack(event->proc);

+	remove_process(event->proc);

+}

+

+static void

+handle_exit_signal(Event *event) {

+	debug(DEBUG_FUNCTION, "handle_exit_signal(pid=%d, signum=%d)", event->proc->pid, event->e_un.signum);

+	if (event->proc->state != STATE_IGNORED) {

+		output_line(event->proc, "+++ killed by %s +++",

+				shortsignal(event->proc, event->e_un.signum));

+	}

+

+	account_current_callstack(event->proc);

+	remove_process(event->proc);

+}

+

+static void

+output_syscall(struct process *proc, const char *name, enum tof tof,

+	       bool left, struct timedelta *spent)

+{

+	if (left)

+		assert(spent == NULL);

+

 	struct library_symbol syscall;

-	if (library_symbol_init(&syscall, 0, name, 0, LS_TOPLT_NONE) >= 0) {

-		syscall.lib = &syscall_lib;

-		(*output)(tof, proc, &syscall);

+	if (init_syscall_symbol(&syscall, name) >= 0) {

+		if (left) {

+			if (! options.summary)

+				output_left(tof, proc, &syscall);

+		} else if (options.summary) {

+			summary_account_call(&syscall, *spent);

+		} else {

+			output_right(tof, proc, &syscall, spent);

+		}

+

 		library_symbol_destroy(&syscall);

 	}

 }

@@ -486,17 +546,19 @@ output_syscall(struct process *proc, const char *name, enum tof tof,

 static void

 output_syscall_left(struct process *proc, const char *name)

 {

-	output_syscall(proc, name, LT_TOF_SYSCALL, &output_left);

+	output_syscall(proc, name, LT_TOF_SYSCALL, true, NULL);

 }

 static void

-output_syscall_right(struct process *proc, const char *name)

+output_syscall_right(struct process *proc, const char *name,

+		     struct timedelta *spent)

 {

-	output_syscall(proc, name, LT_TOF_SYSCALLR, &output_right);

+	output_syscall(proc, name, LT_TOF_SYSCALLR, false, spent);

 }

 static void

-handle_syscall(Event *event) {

+handle_syscall(Event *event)

+{

 	debug(DEBUG_FUNCTION, "handle_syscall(pid=%d, sysnum=%d)", event->proc->pid, event->e_un.sysnum);

 	if (event->proc->state != STATE_IGNORED) {

 		callstack_push_syscall(event->proc, event->e_un.sysnum);

@@ -526,6 +588,8 @@ handle_exec(Event *event)

 	}

 	output_line(proc, "--- Called exec() ---");

+	account_current_callstack(proc);

+

 	if (process_exec(proc) < 0) {

 		fprintf(stderr,

 			"couldn't reinitialize process %d after exec\n", pid);

@@ -549,74 +613,58 @@ handle_arch_syscall(Event *event) {

 	continue_process(event->proc->pid);

 }

-struct timeval current_time_spent;

-

 static void

-calc_time_spent(struct process *proc)

+handle_x_sysret(Event *event, char *(*name_cb)(struct process *, int))

 {

-	struct timeval tv;

-	struct timezone tz;

-	struct timeval diff;

-	struct callstack_element *elem;

-

-	debug(DEBUG_FUNCTION, "calc_time_spent(pid=%d)", proc->pid);

-	elem = &proc->callstack[proc->callstack_depth - 1];

-

-	gettimeofday(&tv, &tz;;

+	debug(DEBUG_FUNCTION, "handle_x_sysret(pid=%d, sysnum=%d)",

+	      event->proc->pid, event->e_un.sysnum);

-	diff.tv_sec = tv.tv_sec - elem->time_spent.tv_sec;

-	if (tv.tv_usec >= elem->time_spent.tv_usec) {

-		diff.tv_usec = tv.tv_usec - elem->time_spent.tv_usec;

-	} else {

-		diff.tv_sec--;

-		diff.tv_usec = 1000000 + tv.tv_usec - elem->time_spent.tv_usec;

-	}

-	current_time_spent = diff;

-}

+	unsigned d = event->proc->callstack_depth;

+	assert(d > 0);

+	struct callstack_element *elem = &event->proc->callstack[d - 1];

+	assert(elem->is_syscall);

-static void

-handle_sysret(Event *event) {

-	debug(DEBUG_FUNCTION, "handle_sysret(pid=%d, sysnum=%d)", event->proc->pid, event->e_un.sysnum);

 	if (event->proc->state != STATE_IGNORED) {

-		if (opt_T || options.summary) {

-			calc_time_spent(event->proc);

-		}

+		struct timedelta spent = calc_time_spent(elem->enter_time);

 		if (options.syscalls)

 			output_syscall_right(event->proc,

-					     sysname(event->proc,

-						     event->e_un.sysnum));

+					     name_cb(event->proc,

+						     event->e_un.sysnum),

+					     &spent);

-		assert(event->proc->callstack_depth > 0);

-		unsigned d = event->proc->callstack_depth - 1;

-		assert(event->proc->callstack[d].is_syscall);

 		callstack_pop(event->proc);

 	}

 	continue_after_syscall(event->proc, event->e_un.sysnum, 1);

 }

 static void

-handle_arch_sysret(Event *event) {

-	debug(DEBUG_FUNCTION, "handle_arch_sysret(pid=%d, sysnum=%d)", event->proc->pid, event->e_un.sysnum);

-	if (event->proc->state != STATE_IGNORED) {

-		if (opt_T || options.summary) {

-			calc_time_spent(event->proc);

-		}

-		if (options.syscalls)

-			output_syscall_right(event->proc,

-					     arch_sysname(event->proc,

-							  event->e_un.sysnum));

-		callstack_pop(event->proc);

-	}

-	continue_process(event->proc->pid);

+handle_sysret(Event *event)

+{

+	handle_x_sysret(event, &sysname);

+}

+

+static void

+handle_arch_sysret(Event *event)

+{

+	handle_x_sysret(event, &arch_sysname);

 }

 static void

 output_right_tos(struct process *proc)

 {

 	size_t d = proc->callstack_depth;

+	assert(d > 0);

 	struct callstack_element *elem = &proc->callstack[d - 1];

-	if (proc->state != STATE_IGNORED)

-		output_right(LT_TOF_FUNCTIONR, proc, elem->c_un.libfunc);

+	assert(! elem->is_syscall);

+

+	if (proc->state != STATE_IGNORED) {

+		struct timedelta spent = calc_time_spent(elem->enter_time);

+		if (options.summary)

+			summary_account_call(elem->c_un.libfunc, spent);

+		else

+			output_right(LT_TOF_FUNCTIONR, proc, elem->c_un.libfunc,

+				     &spent);

+	}

 }

 #ifndef ARCH_HAVE_SYMBOL_RET

@@ -645,14 +693,8 @@ handle_breakpoint(Event *event)

 	for (i = event->proc->callstack_depth - 1; i >= 0; i--) {

 		if (brk_addr == event->proc->callstack[i].return_addr) {

-			for (j = event->proc->callstack_depth - 1; j > i; j--) {

+			for (j = event->proc->callstack_depth - 1; j > i; j--)

 				callstack_pop(event->proc);

-			}

-			if (event->proc->state != STATE_IGNORED) {

-				if (opt_T || options.summary) {

-					calc_time_spent(event->proc);

-				}

-			}

 			struct library_symbol *libsym =

 			    event->proc->callstack[i].c_un.libfunc;

@@ -705,11 +747,14 @@ handle_breakpoint(Event *event)

 	/* breakpoint_on_hit may delete its own breakpoint, so we have

 	 * to look it up again.  */

 	if ((sbp = address2bpstruct(leader, brk_addr)) != NULL) {

+

 		if (event->proc->state != STATE_IGNORED

 		    && sbp->libsym != NULL) {

 			event->proc->stack_pointer = get_stack_pointer(event->proc);

 			callstack_push_symfunc(event->proc, sbp);

-			output_left(LT_TOF_FUNCTION, event->proc, sbp->libsym);

+			if (! options.summary)

+				output_left(LT_TOF_FUNCTION, event->proc,

+					    sbp->libsym);

 		}

 		breakpoint_on_continue(sbp, event->proc);

@@ -743,7 +788,7 @@ callstack_push_syscall(struct process *proc, int sysnum)

 	proc->callstack_depth++;

 	if (opt_T || options.summary) {

 		struct timezone tz;

-		gettimeofday(&elem->time_spent, &tz;;

+		gettimeofday(&elem->enter_time, &tz;;

 	}

 }

@@ -781,7 +826,7 @@ callstack_push_symfunc(struct process *proc, struct breakpoint *bp)

 	if (opt_T || options.summary) {

 		struct timezone tz;

-		gettimeofday(&elem->time_spent, &tz;;

+		gettimeofday(&elem->enter_time, &tz;;

 	}

 }

diff --git a/libltrace.c b/libltrace.c

index 2d910a1..0112c9f 100644

--- a/libltrace.c

+++ b/libltrace.c

@@ -32,11 +32,12 @@

 #include <string.h>

 #include <unistd.h>

+#include "backend.h"

 #include "common.h"

 #include "proc.h"

-#include "read_config_file.h"

-#include "backend.h"

 #include "prototype.h"

+#include "read_config_file.h"

+#include "summary.h"

 char *command = NULL;

diff --git a/options.h b/options.h

index 6c28ed9..d0df3a7 100644

--- a/options.h

+++ b/options.h

@@ -1,6 +1,6 @@

 /*

  * This file is part of ltrace.

- * Copyright (C) 2012 Petr Machata, Red Hat Inc.

+ * Copyright (C) 2012,2013 Petr Machata, Red Hat Inc.

  * Copyright (C) 2009,2010 Joe Damato

  * Copyright (C) 1998,2002,2008 Juan Cespedes

  * Copyright (C) 2006 Ian Wienand

@@ -103,12 +103,6 @@ int parse_colon_separated_list(const char *paths, struct vect *vec);

 /* Vector of struct opt_F_t.  */

 extern struct vect opt_F;

-struct opt_c_struct {

-	int count;

-	struct timeval tv;

-};

-extern struct dict *dict_opt_c;

-

 extern char **process_options(int argc, char **argv);

 #endif /* _OPTIONS_H_ */

diff --git a/output.c b/output.c

index edf4522..82b6a5e 100644

--- a/output.c

+++ b/output.c

@@ -44,16 +44,12 @@

 #include "param.h"

 #include "proc.h"

 #include "prototype.h"

+#include "summary.h"

 #include "type.h"

 #include "value.h"

 #include "value_dict.h"

-/* TODO FIXME XXX: include in common.h: */

-extern struct timeval current_time_spent;

-

-struct dict *dict_opt_c = NULL;

-

-static struct process *current_proc = 0;

+static struct process *current_proc = NULL;

 static size_t current_depth = 0;

 static int current_column = 0;

@@ -498,9 +494,8 @@ void

 output_left(enum tof type, struct process *proc,

 	    struct library_symbol *libsym)

 {

-	if (options.summary) {

-		return;

-	}

+	assert(! options.summary);

+

 	if (current_proc) {

 		fprintf(options.output, " <unfinished ...>\n");

 		current_column = 0;

@@ -572,70 +567,21 @@ output_left(enum tof type, struct process *proc,

 	stel->out.need_delim = need_delim;

 }

-static void

-free_stringp_cb(const char **stringp, void *data)

-{

-	free((char *)*stringp);

-}

-

 void

-output_right(enum tof type, struct process *proc, struct library_symbol *libsym)

+output_right(enum tof type, struct process *proc, struct library_symbol *libsym,

+	     struct timedelta *spent)

 {

+	assert(! options.summary);

+

 	struct prototype *func = lookup_symbol_prototype(proc, libsym);

 	if (func == NULL)

 		return;

-again:

-	if (options.summary) {

-		if (dict_opt_c == NULL) {

-			dict_opt_c = malloc(sizeof(*dict_opt_c));

-			if (dict_opt_c == NULL) {

-			oom:

-				fprintf(stderr,

-					"Can't allocate memory for "

-					"keeping track of -c.\n");

-				free(dict_opt_c);

-				options.summary = 0;

-				goto again;

-			}

-			DICT_INIT(dict_opt_c, char *, struct opt_c_struct,

-				  dict_hash_string, dict_eq_string, NULL);

-		}

-

-		struct opt_c_struct *st

-			= DICT_FIND_REF(dict_opt_c, &libsym->name,

-					struct opt_c_struct);

-		if (st == NULL) {

-			const char *na = strdup(libsym->name);

-			struct opt_c_struct new_st = {.count = 0, .tv = {0, 0}};

-			if (na == NULL

-			    || DICT_INSERT(dict_opt_c, &na, &new_st) < 0) {

-				free((char *)na);

-				DICT_DESTROY(dict_opt_c, const char *,

-					     struct opt_c_struct,

-					     free_stringp_cb, NULL, NULL);

-				goto oom;

-			}

-			st = DICT_FIND_REF(dict_opt_c, &libsym->name,

-					   struct opt_c_struct);

-			assert(st != NULL);

-		}

-

-		if (st->tv.tv_usec + current_time_spent.tv_usec > 1000000) {

-			st->tv.tv_usec += current_time_spent.tv_usec - 1000000;

-			st->tv.tv_sec++;

-		} else {

-			st->tv.tv_usec += current_time_spent.tv_usec;

-		}

-		st->count++;

-		st->tv.tv_sec += current_time_spent.tv_sec;

-		return;

-	}

-

-	if (current_proc && (current_proc != proc ||

-			    current_depth != proc->callstack_depth)) {

+	if (current_proc != NULL

+		    && (current_proc != proc

+			|| current_depth != proc->callstack_depth)) {

 		fprintf(options.output, " <unfinished ...>\n");

-		current_proc = 0;

+		current_proc = NULL;

 	}

 	if (current_proc != proc) {

 		begin_of_line(proc, type == LT_TOF_FUNCTIONR, 1);

@@ -689,10 +635,12 @@ again:

 		value_destroy(&retval);

 	if (opt_T) {

+		assert(spent != NULL);

 		fprintf(options.output, " <%lu.%06d>",

-			(unsigned long)current_time_spent.tv_sec,

-			(int)current_time_spent.tv_usec);

+			(unsigned long) spent->tm.tv_sec,

+			(int) spent->tm.tv_usec);

 	}

+

 	fprintf(options.output, "\n");

 #if defined(HAVE_LIBUNWIND)

@@ -746,7 +694,7 @@ again:

 	}

 #endif /* defined(HAVE_LIBUNWIND) */

-	current_proc = 0;

+	current_proc = NULL;

 	current_column = 0;

 }

diff --git a/output.h b/output.h

index b9f0518..2e74d61 100644

--- a/output.h

+++ b/output.h

@@ -1,6 +1,6 @@

 /*

  * This file is part of ltrace.

- * Copyright (C) 2011, 2012 Petr Machata, Red Hat Inc.

+ * Copyright (C) 2011, 2012, 2013 Petr Machata, Red Hat Inc.

  * Copyright (C) 2009 Juan Cespedes

  *

  * This program is free software; you can redistribute it and/or

@@ -28,7 +28,8 @@ void output_line(struct process *proc, const char *fmt, ...);

 void output_left(enum tof type, struct process *proc,

 		 struct library_symbol *libsym);

 void output_right(enum tof type, struct process *proc,

-		  struct library_symbol *libsym);

+		  struct library_symbol *libsym,

+		  struct timedelta *spent);

 /* This function is for emitting lists of comma-separated strings.

  *

diff --git a/proc.h b/proc.h

index e8032fa..64f8fe2 100644

--- a/proc.h

+++ b/proc.h

@@ -66,7 +66,7 @@ struct callstack_element {

 	} c_un;

 	int is_syscall;

 	arch_addr_t return_addr;

-	struct timeval time_spent;

+	struct timeval enter_time;

 	struct fetch_context *fetch_context;

 	struct value_dict *arguments;

 	struct output_state out;

diff --git a/summary.c b/summary.c

index 9e22086..9103f71 100644

--- a/summary.c

+++ b/summary.c

@@ -22,11 +22,15 @@

 #include "config.h"

+#include <sys/time.h>

 #include <stdio.h>

 #include <stdlib.h>

-#include <sys/time.h>

+#include <string.h>

-#include "common.h"

+#include "summary.h"

+#include "dict.h"

+#include "library.h"

+#include "options.h"

 struct entry_st {

 	const char *name;

@@ -40,6 +44,32 @@ struct fill_struct_data {

 	unsigned long tot_usecs;

 };

+struct opt_c_struct {

+	int count;

+	struct timeval tv;

+};

+

+static struct dict *dict_opt_c;

+

+struct timedelta

+calc_time_spent(struct timeval start)

+{

+	struct timeval tv;

+	gettimeofday(&tv, NULL);

+

+	struct timeval diff;

+	diff.tv_sec = tv.tv_sec - start.tv_sec;

+	if (tv.tv_usec >= start.tv_usec) {

+		diff.tv_usec = tv.tv_usec - start.tv_usec;

+	} else {

+		diff.tv_sec--;

+		diff.tv_usec = 1000000 + tv.tv_usec - start.tv_usec;

+	}

+

+	struct timedelta ret = { diff };

+	return ret;

+}

+

 static enum callback_status

 fill_struct(const char **namep, struct opt_c_struct *st, void *u)

 {

@@ -114,3 +144,58 @@ show_summary(void)

 	vect_destroy(&cdata.entries, NULL, NULL);

 }

+

+static void

+free_stringp_cb(const char **stringp, void *data)

+{

+	free((char *)*stringp);

+}

+

+void

+summary_account_call(struct library_symbol *libsym, struct timedelta spent)

+{

+	assert(options.summary);

+

+	if (dict_opt_c == NULL) {

+		dict_opt_c = malloc(sizeof(*dict_opt_c));

+		if (dict_opt_c == NULL) {

+		oom:

+			fprintf(stderr,

+				"Can't allocate memory for "

+				"keeping track of -c.\n");

+			free(dict_opt_c);

+			options.summary = 0;

+			return;

+		}

+		DICT_INIT(dict_opt_c, char *, struct opt_c_struct,

+			  dict_hash_string, dict_eq_string, NULL);

+	}

+

+	struct opt_c_struct *st = DICT_FIND_REF(dict_opt_c, &libsym->name,

+						struct opt_c_struct);

+	if (st == NULL) {