Why does gdb stop at a different line than �i b� shows while returning from function? Post: 302679737

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Top Forums Programming Why does gdb stop at a different line than �i b� shows while returning from function? Post 302679737 by ijustneeda on Tuesday 31st of July 2012 02:24:48 PM

07-31-2012

Banned

Why does gdb stop at a different line than �i b� shows while returning from function?

Here is the program I am trying to debug:

Code:

#include <stdio.h>
int i = 5;

int main(void)
{
    int x = 3;

    display(x);
    return 0;
}


void display(int x)
{
for ( i=0; i<x; ++i ) {
    printf("i is %d.\n", i);
}
}

This code is coming from here Peter's gdb Tutorial: Stepping And Resuming. Here is the problem:

Code:

(gdb) break display 
Breakpoint 1 at 0x40051e: file try5.c, line 15.
(gdb) run
Starting program: /home/ja/gdb/learning/try5 

Breakpoint 1, display (x=3) at try5.c:15
(gdb) frame 1
#1  0x000000000040050c in main () at try5.c:8
(gdb) break 
Breakpoint 2 at 0x40050c: file try5.c, line 8.
(gdb) c
Continuing.
i is 0.
i is 1.
i is 2.

Breakpoint 2, main () at try5.c:9
(gdb) i b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x000000000040051e in display at try5.c:15
    breakpoint already hit 1 time
2       breakpoint     keep y   0x000000000040050c in main at try5.c:8
    breakpoint already hit 1 time
(gdb) c
Continuing.

Program exited normally.
(gdb) q

Debugger finished

It was supposed to stop at line 8 in main() but it stopped at line 9 it main(). For me it's misleading. I think it should stop at line 9, because this is what 'break' commands does - sets a break point at the very next instruction. But why "info breakpoints" said that the break point was set at line 8?

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xwcdrawstring

XmbDrawString(3X11)						  XLIB FUNCTIONS					       XmbDrawString(3X11)

NAME

       XmbDrawString, XwcDrawString, Xutf8DrawString - draw text using a single font set

SYNTAX

       void XmbDrawString(display, d, font_set, gc, x, y, string, num_bytes)
	     Display *display;
	     Drawable d;
	     XFontSet font_set;
	     GC gc;
	     int x, y;
	     char *string;
	     int num_bytes;

       void XwcDrawString(display, d, font_set, gc, x, y, string, num_wchars)
	     Display *display;
	     Drawable d;
	     XFontSet font_set;
	     GC gc;
	     int x, y;
	     wchar_t *string;
	     int num_wchars;

       void Xutf8DrawString(display, d, font_set, gc, x, y, string, num_bytes)
	     Display *display;
	     Drawable d;
	     XFontSet font_set;
	     GC gc;
	     int x, y;
	     char *string;
	     int num_bytes;

ARGUMENTS

       d	 Specifies the drawable.

       display	 Specifies the connection to the X server.

       font_set  Specifies the font set.

       gc	 Specifies the GC.

       num_bytes Specifies the number of bytes in the string argument.

       num_wchars
		 Specifies the number of characters in the string argument.

       string	 Specifies the character string.

       x
       y	 Specify the x and y coordinates.

DESCRIPTION

       The XmbDrawString, XwcDrawString and Xutf8DrawString functions draw the specified text with the foreground pixel.  When the XFontSet has
       missing charsets, each unavailable character is drawn with the default string returned by XCreateFontSet.  The behavior for an invalid
       codepoint is undefined.

       The function Xutf8DrawString is an XFree86 extension introduced in XFree86 4.0.2. Its presence is indicated by the macro
       X_HAVE_UTF8_STRING.

SEE ALSO

       XDrawImageString(3X11), XDrawString(3X11), XDrawText(3X11), XmbDrawImageString(3X11), XmbDrawText(3X11)
       Xlib - C Language X Interface

X Version 11							    Release 6.6 					       XmbDrawString(3X11)

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