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Wiki page apps_efl_debugging changed with summary [] by Raster

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@ -1,51 +1,46 @@
~~Title: Apps debugging~~ ~~Title: Apps debugging~~
==== EFL application debugging ==== ==== EFL application debugging ====
This tutorial goal is to help you debug your EFL applications with several > //Please also see [[docs-efl-debug]]. This should probably be merged with this page.//
use cases that you can reproduce.
It gives you approaches to know if the bug comes from your application or
from EFL libraries.
Then, if you are sure the bug does not come from your This tutorial's goal is to help you debug your EFL applications with several use cases that you can reproduce. It gives you approaches to know if the bug comes from your application or from the EFL libraries.
application, you can [[/debugging/report_bugs|report a bug]].
Then, if you are sure the bug does not come from your application, you can [[/debugging/report_bugs|report a bug]].
In this tutorial we'll cover log levels and tracing the sources of bugs:
In this tutorial, log level and 4 use cases will be studied:
- [[apps_efl_debugging#Log level]] - [[apps_efl_debugging#Log level]]
- [[apps_efl_debugging#Wrong function on an object]] - [[apps_efl_debugging#Wrong function on an object]]
- [[apps_efl_debugging#Segfault in callback function]] - [[apps_efl_debugging#Segfault in callback function]]
- [[apps_efl_debugging#Memory leak]] - [[apps_efl_debugging#Memory leak]]
- [[apps_efl_debugging#Clouseau]] - [[apps_efl_debugging#Clouseau]]
Before debugging, make sure your debug symbols are enabled. If not, go to the Before debugging, make sure your debug symbols are enabled. If not, go to the [[/docs-efl-start#Enable_debug_symbols_Optional|Enable debug symbols]] section.
[[/docs-efl-start#Enable_debug_symbols_Optional|Enable debug symbols]]
section.
You can also have a look at the You can also have a look at the [[https://phab.enlightenment.org/w/coding_convention/|EFL coding convention]] if you modify code and want to send patches.
[[https://phab.enlightenment.org/w/coding_convention/|EFL coding convention]].
=== Log level === === Log level ===
The Eina log module provides log level traces, there are 5 debugging levels The Eina log module provides log level traces, there are 5 debugging levels with their respective macros:
with their respective macros:
- Critical log level: EINA_LOG_LEVEL_CRITICAL() ^Level ^Macro ^
- Error log level: EINA_LOG_ERR() |Critical |EINA_LOG_LEVEL_CRITICAL() |
- Warning log level: EINA_LOG_WARN() |Error |EINA_LOG_ERR() |
- Info log level: EINA_LOG_INFO() |Warning |EINA_LOG_WARN() |
- Debug log level: EINA_LOG_DBG() |Info |EINA_LOG_INFO() |
|Debug |EINA_LOG_DBG() |
Global log level can be set with the EINA_LOG_LEVEL environment variable. Global log level can be set with the ''EINA_LOG_LEVEL'' environment variable.
<code bash> <code bash>
#debug log level # Debug log level
EINA_LOG_LEVEL=5 ./my_test_efl EINA_LOG_LEVEL=5 ./my_test_efl
</code> </code>
The EINA_LOG_LEVELS variable provide a way to activate logs only for specific The ''EINA_LOG_LEVELS'' variable provide a way to activate logs only for specific modules.
modules.
<code bash> <code bash>
#it will set respectively module1 and module2 level to 5 and to 2 # This will set module1 and module2 respectively to log level 5 and 2
EINA_LOG_LEVELS=module1:5,module2:2 ./my_test_efl EINA_LOG_LEVELS=module1:5,module2:2 ./my_test_efl
</code> </code>
@ -53,57 +48,47 @@ EINA_LOG_LEVELS=module1:5,module2:2 ./my_test_efl
=== Wrong function on an object === === Wrong function on an object ===
The code below creates 3 Elementary objects: win, box and btn. It displays a The code below creates 3 Elementary objects: win, box and btn. It displays a window with an //OK// button that closes the window when it is clicked. Here, the //elm_box_pack_end()// function is called on a wrong object (win) which generates an error:
window with an //OK// button that closes the window when it is clicked.
Here, the //elm_box_pack_end()// function is called on a wrong object (win)
which generates an error:
<code c hello.c> <code c hello.c>
//hello.c
#include <Elementary.h> #include <Elementary.h>
static void
static void
on_done(void *data, Evas_Object *obj, void *event_info) on_done(void *data, Evas_Object *obj, void *event_info)
{ {
// quit the mainloop (elm_run function will return) // quit the mainloop (elm_run function will return)
elm_exit(); elm_exit();
} }
EAPI_MAIN int EAPI_MAIN int
elm_main(int argc, char **argv) elm_main(int argc, char **argv)
{ {
Evas_Object *win, *box, *btn; Evas_Object *win, *box, *btn;
// new window // new window
win = elm_win_util_standard_add("hello", "Hello"); win = elm_win_util_standard_add("hello", "Hello");
// add a box object
box = elm_box_add(win);
// add object as a resize object for the window (controls window minimum
// size as well as gets resized if window is resized)
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "OK"
elm_object_text_set(btn, "OK");
// pack the button at the end of the box
/****ERROR****/
elm_box_pack_end(win, btn); //win instead of box
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(win, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// add a box object // run the mainloop and process events and callbacks
box = elm_box_add(win); elm_run();
return 0;
// add object as a resize object for the window (controls window minimum
// size as well as gets resized if window is resized)
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "OK"
elm_object_text_set(btn, "OK");
// pack the button at the end of the box
/****ERROR****/
elm_box_pack_end(win, btn); //win instead of box
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(win, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// run the mainloop and process events and callbacks
elm_run();
return 0;
} }
ELM_MAIN() ELM_MAIN()
</code> </code>
@ -116,18 +101,9 @@ gcc -Wall -O1 -march=native -g -ggdb3 -o hello hello.c `pkg-config --cflags --li
ERR<13670>:eo lib/eo/eo.c:780 _eo_api_op_id_get() in elm_box.eo.c:48: unable to resolve regular api func 'elm_obj_box_pack_end' 0x7f1128f50faf in class 'Elm_Win'. ERR<13670>:eo lib/eo/eo.c:780 _eo_api_op_id_get() in elm_box.eo.c:48: unable to resolve regular api func 'elm_obj_box_pack_end' 0x7f1128f50faf in class 'Elm_Win'.
</code> </code>
Here, the error log says that the //elm_obj_box_pack_end// Here, the error log says that the ''elm_obj_box_pack_end'' is not in the api of Elm_win, and so, that this error is coming from your application and not from EFL. Guessing you have a more complicated application, this trace is not enough to find in your code where is the problem. Fortunately, EFL provide a macro to provide backtraces: //EINA_LOG_ABORT//.
is not in the api of Elm_win, and so, that this error is coming from your
application and not from EFL. Guessing you have a more complicated
application, this trace is not enough to find in your code where is the
problem. Fortunately, EFL provide a macro to provide backtraces :
//EINA_LOG_ABORT//.
In fact, a message generated by CRI macro automatically call abort() once some In fact, a message generated by CRI macro can automatically call abort() once some given level message is printed. This is controlled by environment variable //EINA_LOG_ABORT// and the level to be considered critical with //EINA_LOG_ABORT_LEVEL//. This means the program will stop at the first error met with these two variables.
given level message is printed. This is controlled by environment variable
//EINA_LOG_ABORT// and the level to be considered critical with
//EINA_LOG_ABORT_LEVEL//. That is to say the program will stop at the first
error met with these two variables.
Get a backtrace with the following command: Get a backtrace with the following command:
@ -167,8 +143,7 @@ Go to frame 7:
34 elm_box_pack_end(win, btn); //win instead of box 34 elm_box_pack_end(win, btn); //win instead of box
</code> </code>
You finally know that win is used as a parameter of //elm_box_pack_end// instead of You finally see that win is used as a parameter of //elm_box_pack_end// instead of box, at line 34 of hello.c.
box, at line 34 of hello.c.
---- ----
@ -178,57 +153,50 @@ Let's make a segfault in a callback function:
<code c helloworld.c> <code c helloworld.c>
#include <Elementary.h> #include <Elementary.h>
static void
static void
on_done(void *data, Evas_Object *obj, void *event_info) on_done(void *data, Evas_Object *obj, void *event_info)
{ {
int *pi=(int *)0; //pointer on 0x0!!! int *pi = (int *)0; // pointer on 0x0!!!
/**SEGFAULT**/ /**SEGFAULT**/
int i=*pi; //segfault accessing 0x0 address int i = *pi; // segfault accessing 0x0 address
// quit the mainloop (elm_run function will return) // quit the mainloop (elm_run function will return)
elm_exit(); elm_exit();
} }
EAPI_MAIN int EAPI_MAIN int
elm_main(int argc, char **argv) elm_main(int argc, char **argv)
{ {
Evas_Object *win, *box, *btn; Evas_Object *win, *box, *btn;
// new window // new window
win = elm_win_util_standard_add("hello", "Hello"); win = elm_win_util_standard_add("hello", "Hello");
// add a box object
box = elm_box_add(win);
// add object as a resize object for the window
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "SEG"
elm_object_text_set(btn, "SEG");
// pack the button at the end of the box
elm_box_pack_end(box, btn);
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(btn, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// add a box object // run the mainloop and process events and callbacks
box = elm_box_add(win); elm_run();
return 0;
// add object as a resize object for the window
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "SEG"
elm_object_text_set(btn, "SEG");
// pack the button at the end of the box
elm_box_pack_end(box, btn);
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(btn, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// run the mainloop and process events and callbacks
elm_run();
return 0;
} }
ELM_MAIN() ELM_MAIN()
</code> </code>
This program segfaults when the seg button is clicked that is to say that the This program segfaults when the seg button is clicked that is to say that the program segfaults in the callback function:
program segfaults in the callback function:
//**__How to get that with GDB?__**// //**__How to get that with GDB?__**//
@ -272,14 +240,14 @@ gdb helloworld
#21 0x0000000000400dc2 in main (argc=1, argv=0x7fffffffe398) at helloworld.c:42 #21 0x0000000000400dc2 in main (argc=1, argv=0x7fffffffe398) at helloworld.c:42
</code> </code>
As you can see, the program failed in the callback function, meaning the The program failed in the callback function, meaning the problem comes from your application, even if the callback is called from Evas.
problem comes from your application, even if callback functions are called
from evas. Let's go a bit more deeply:
- Go to frame 0, the callback function
- Print pi pointer
- Print what it points to
Let's go deeply:
-Go to frame 0, the callback function
-print pi pointer
-print what it points
<code bash> <code bash>
(gdb) fr 0 (gdb) fr 0
#0 0x0000000000400c86 in on_done (data=0x0, obj=0x8000000800000041, event_info=0x0) at helloworld.c:6 #0 0x0000000000400c86 in on_done (data=0x0, obj=0x8000000800000041, event_info=0x0) at helloworld.c:6
@ -290,91 +258,78 @@ $1 (int *) 0x0
Cannot access memory at address 0x0 Cannot access memory at address 0x0
</code> </code>
Here in this easy example, the problem is quite clear, address 0x0 cannot be In this easy example, the problem is quite clear, address 0x0 cannot be accessed! Eventually, even if the callback functions are called from Evas and so generate lots of traces, it is quite simple to know where the bug is coming from.
accessed! Eventually, even if callback functions are called from evas and so
generate lots of traces, it is quite simple to know where the bug is coming
from.
---- ----
=== Memory leak === === Memory leak ===
Valgrind is composed of several tools especially memcheck which checks: Valgrind is composed of several tools especially memcheck which checks:
- read/write access
- memory leaks
- non initialized variables
In this example, an Eina array is created on a callback function but it is - Read/write access
never freed. This generates a memory leak. - Memory leaks
- Non-initialized variables
In this example, an Eina array is created in a callback function but it is never freed. This generates a memory leak.
<code c hello_valgrind.c> <code c hello_valgrind.c>
//hello.c
#include <Elementary.h> #include <Elementary.h>
static void
static void
on_done(void *data, Evas_Object *obj, void *event_info) on_done(void *data, Evas_Object *obj, void *event_info)
{ {
Eina_Array *array; Eina_Array *array;
eina_init(); unsigned int i;
array = eina_array_new(100);
eina_array_step_set(array, sizeof(*array), 20);
unsigned int i;
for (i = 0; i < 20; i++)
eina_array_push(array, strdup("hello"));
/****To free array****/ eina_init();
//while (eina_array_count(array)) array = eina_array_new(100);
//free(eina_array_pop(array)); eina_array_step_set(array, sizeof(*array), 20);
//eina_array_free(array); for (i = 0; i < 20; i++) eina_array_push(array, strdup("hello"));
//eina_shutdown(); /****To free array****/
//while (eina_array_count(array))
//free(eina_array_pop(array));
//eina_array_free(array);
// quit the mainloop (elm_run function will return) //eina_shutdown();
elm_exit();
// quit the mainloop (elm_run function will return)
elm_exit();
} }
EAPI_MAIN int EAPI_MAIN int
elm_main(int argc, char **argv) elm_main(int argc, char **argv)
{ {
Evas_Object *win, *box, *btn; Evas_Object *win, *box, *btn;
// new window // new window
win = elm_win_util_standard_add("hello", "Hello"); win = elm_win_util_standard_add("hello", "Hello");
// add a box object
box = elm_box_add(win);
// add object as a resize object for the window (controls window minimum
// size as well as gets resized if window is resized)
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "SEG"
elm_object_text_set(btn, "SEG");
// pack the button at the end of the box
elm_box_pack_end(box, btn);
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(btn, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// add a box object // run the mainloop and process events and callbacks
box = elm_box_add(win); elm_run();
return 0;
// add object as a resize object for the window (controls window minimum
// size as well as gets resized if window is resized)
elm_win_resize_object_add(win, box);
evas_object_show(box);
// add a button
btn = elm_button_add(win);
// set default text of button to "SEG"
elm_object_text_set(btn, "SEG");
// pack the button at the end of the box
elm_box_pack_end(box, btn);
evas_object_show(btn);
// call on_done when button is clicked
evas_object_smart_callback_add(btn, "clicked", on_done, NULL);
//show the window
evas_object_show(win);
// run the mainloop and process events and callbacks
elm_run();
return 0;
} }
ELM_MAIN() ELM_MAIN()
</code> </code>
There can be other traces in the HEAD SUMMARY but here we are just interested There can be other traces in the HEAD SUMMARY but here we are just interested in the memory leak due to your application, so you may have to ignore things not relevant to your code.
at leak memories due to your application, so you may have to find
those which directly depends on your application.
<code bash> <code bash>
... ...
@ -402,93 +357,85 @@ in loss record 349 of 417
... ...
</code> </code>
All the memory access pass through valgrind, so it shows you a backtrace when All the memory accesses pass through Valgrind, so it shows you a backtrace when an allocation is made and not freed.
an allocation is done and not freed.
As you see in the backtrace, an allocation took place in the //eina_array_new As in the backtrace, an allocation took place in the //eina_array_new function//. This function itself is called from //on_done// function on hello.c file. You can go up, but remember that a callback function is called from Evas, so there is a big chance that the allocation is made in your callback function.
function//.
This function itself is called from //on_done// function on hello.c file.
You can go up but remember that a callback function is called from evas, so
there are big chances that the allocation is done in your callback function.
---- ----
=== Clouseau === === Clouseau ===
Clouseau is the EFL UI Inspection tool. It makes it easy to query UI Clouseau is the EFL UI Inspection tool. It makes it easy to query UI components and structure. Moreover it supports remote debugging and works with GDB. In fact, Clouseau can also give information about different widgets with their properties.
components and structure. Moreover it supports remote debugging and works with
Gdb.
In fact, Clouseau gives information about the different widgets with You can get Clouseau from git:
their properties.
You can get Clousseau fom git.
<code bash> <code bash>
git clone http://git.enlightenment.org/tools/clouseau.git git clone http://git.enlightenment.org/tools/clouseau.git
</code> </code>
Here is a simple helloworld to test with clouseau, it displays a window Here is a simple helloworld to test with Clouseau, it displays a window with some text and one button to exit.
with some text and one button to exit.
<code c hello_clouseau.c> <code c hello_clouseau.c>
#include <Elementary.h> #include <Elementary.h>
static void
static void
on_done(void *data, Evas_Object *obj, void *event_info) on_done(void *data, Evas_Object *obj, void *event_info)
{ {
// quit the mainloop (elm_run function will return) // quit the mainloop (elm_run function will return)
elm_exit(); elm_exit();
} }
EAPI_MAIN int EAPI_MAIN int
elm_main(int argc, char **argv) elm_main(int argc, char **argv)
{ {
Evas_Object *win, *box, *lab, *btn; Evas_Object *win, *box, *lab, *btn;
// new window - new background
win = elm_win_util_standard_add("hello", "Hello"); // new window - new background
// when the user clicks "close" on a window there is a request to delete win = elm_win_util_standard_add("hello", "Hello");
evas_object_smart_callback_add(win, "delete,request", on_done, NULL); // when the user clicks "close" on a window there is a request to delete
// add a box object - default is vertical. a box holds children in a row, evas_object_smart_callback_add(win, "delete,request", on_done, NULL);
// either horizontally or vertically. nothing more. // add a box object - default is vertical. a box holds children in a row,
box = elm_box_add(win); // either horizontally or vertically. nothing more.
// make the box horizontal box = elm_box_add(win);
elm_box_horizontal_set(box, EINA_TRUE); // make the box horizontal
// add object as a resize object for the window (controls window minimum elm_box_horizontal_set(box, EINA_TRUE);
// size as well as gets resized if window is resized) // add object as a resize object for the window (controls window minimum
elm_win_resize_object_add(win, box); // size as well as gets resized if window is resized)
evas_object_show(box); elm_win_resize_object_add(win, box);
// add a label widget, set the text and put it in the pad frame evas_object_show(box);
lab = elm_label_add(win); // add a label widget, set the text and put it in the pad frame
// set default text of the label lab = elm_label_add(win);
elm_object_text_set(lab, "Hello out there world!"); // set default text of the label
// pack the label at the end of the box elm_object_text_set(lab, "Hello out there world!");
elm_box_pack_end(box, lab); // pack the label at the end of the box
evas_object_show(lab); elm_box_pack_end(box, lab);
// add an ok button evas_object_show(lab);
btn = elm_button_add(win); // add an ok button
// set default text of button to "OK" btn = elm_button_add(win);
elm_object_text_set(btn, "OK"); // set default text of button to "OK"
// pack the button at the end of the box elm_object_text_set(btn, "OK");
elm_box_pack_end(box, btn); // pack the button at the end of the box
evas_object_show(btn); elm_box_pack_end(box, btn);
// call on_done when button is clicked evas_object_show(btn);
evas_object_smart_callback_add(btn, "clicked", on_done, NULL); // call on_done when button is clicked
int *p; evas_object_smart_callback_add(btn, "clicked", on_done, NULL);
// now we are done, show the window // now we are done, show the window
evas_object_show(win); evas_object_show(win);
// run the mainloop and process events and callbacks
elm_run(); // run the mainloop and process events and callbacks
return 0; elm_run();
return 0;
} }
ELM_MAIN() ELM_MAIN()
</code> </code>
To launch it with clouseau : To launch it with Clouseau:
<code bash> <code bash>
clousseau ./helloworld clousseau ./helloworld
</code> </code>
Here below a screenshot of clouseau and the helloworld application : Here below is a screenshot of Clouseau and the helloworld application:
{{:clouseau.png?direct|Clouseau}} {{:clouseau.png?direct|Clouseau}}
@ -496,10 +443,9 @@ Here below a screenshot of clouseau and the helloworld application :
- Red : the composition of Helloworld application - Red : the composition of Helloworld application
- Blue : The characteristic of Elm and Evas_object - Blue : The characteristic of Elm and Evas_object
Let's see now what gives us clouseau to compare with code: Let's see now what Clouseau shows and how it relates to the code:
First thing the application is composed of 3 main widgets : //Elm_win//, The application is composed of 3 main widgets : //Elm_win//, //Elm_bg//, //Elm_box//.
//Elm_bg//, //Elm_box//.
<code c> <code c>
win = elm_win_util_standard_add("hello", "Hello"); win = elm_win_util_standard_add("hello", "Hello");
@ -507,9 +453,7 @@ win = elm_win_util_standard_add("hello", "Hello");
box = elm_box_add(win); box = elm_box_add(win);
</code> </code>
//elm_win_util_standard_add// function creates the window which is the root //elm_win_util_standard_add// function creates the window which is the root widget often used in an application. It also puts a standard background (//Elm_bg//). Then, //elm_box_add// function creates a box widget.
widget often used in an application. It also puts a standard background
(//Elm_bg//). Then, //elm_box_add// function creates a box widget.
<code c> <code c>
elm_box_pack_end(box, lab); elm_box_pack_end(box, lab);
@ -517,36 +461,26 @@ elm_box_pack_end(box, lab);
elm_box_pack_end(box, btn); elm_box_pack_end(box, btn);
</code> </code>
//elm_box_pack_end// add lab and btn widgets at the end of the pack list. So //elm_box_pack_end// add lab and btn widgets at the end of the pack list. So the lab and btn widgets appear as inside the box widget.
the lab and btn widgets appear as inside the box widget.
Otherwise, the blue section shows a certain number of characteristics of the Otherwise, the blue section shows a certain number of characteristics of the object and widget: position, size, color, ... of course some of these characteristics are dynamic and can be updated with the reload button of Clouseau.
object and widget : position, size, color, ... Of course some of these
characteristics are dynamic and can be updated with the reload button of
clouseau.
<code c> <code c>
elm_win_resize_object_add(win, box); elm_win_resize_object_add(win, box);
</code> </code>
This function controls the size of the window such as it takes the minimum This function controls the size of the window such as it takes the minimum place. You can see in the blue section that the minimum and maximum size are equal as a consequence of this function call.
place. You can see in the blue section that the minimum and maximum size are
equal as a consequence of this function call.
//**__Show objects__**// //**__Show objects__**//
As you can see on the picture below, click on setting in yellow and deselect As you can see on the picture below, click on setting in yellow and deselect //Only show Elementary widgets// in red.
//Only show Elementary widgets// in red.
{{:settings_clouseau.png?direct|Clouseau settings}} {{:settings_clouseau.png?direct|Clouseau settings}}
In the result below, you see that all the objects are visible and you see that In the result below, you see that all the objects are visible and you see that widgets are just gathered specific objects.
widgets are just gathered specific objects.
{{:clouseau_object.png?direct|Clouseau Objects}} {{:clouseau_object.png?direct|Clouseau Objects}}
For example in yellow, it is the Elm_box which is an Evas_box composed of an For example in yellow, it is the Elm_box which is an Evas_box composed of an Evas_rectangle, an Elm_Label and an Elm_Button.
Evas_rectangle, an Elm_Label and an ELm_Button.
A Button widget is an Edje_Object which is composed of 4 Evas_rectangle, one A Button widget is an Edje_Object which is composed of 4 Evas_rectangle, one Evas_image and 2 Evas_text.
Evas_image and 2 Evas_text.