| <HTML> |
| <HEAD> |
| <TITLE>Watch Window Help</TITLE> |
| </HEAD> |
| <BODY> |
| <H1>The Watch Window</H1> |
| <H3>Overview</H3> |
| <P>The Watch Window may be used to inspect any collected expression, including |
| global variables, static variables, local variables, function arguments, |
| and registers.</P> |
| |
| <P>Watch Window topics: |
| <UL> |
| <LI><UL><A HREF="#menus">Watch Menu</A> |
| <LI><A HREF="#menus_fmt">Format</A> |
| <LI><A HREF="#menus_remove">Remove</A> |
| </UL> |
| <LI><UL><A HREF="#new">Adding Watch Expressions</A> |
| <LI><A HREF="#new_ent">In the Watch Window</A> |
| <LI><A HREF="#new_src">In the Source Window</A> |
| <LI><A HREF="#new_cast">Casting Pointers</A> |
| </UL> |
| <LI><UL><A HREF="#display">Watch Display</A> |
| <LI><A HREF="#display_deref">Dereferencing Pointers</A> |
| <LI><A HREF="#display_struct">Viewing a Structure or Class</A> |
| <LI><A HREF="#display_popup">Watch Pop-up Menu</A> |
| </UL> |
| </UL></P> |
| |
| <H3><A NAME="menus">Watch Menu</A></H3> |
| The Watch Menu gives on-screen access to the funtions of the Watch Window. |
| To use any of these functions, first use the left mouse button to select an |
| expression from the display. Then select: |
| |
| <DL> |
| <DT><A NAME="menus_fmt">Format</A> |
| <DD>Change the display format of the expression |
| <DT><A NAME="menus_remove">Remove</A> |
| <DD>Remove the expression from the Watch Window |
| </DL> |
| |
| <H3><A NAME="new">Adding Watch Expressions</A></H3> |
| <A NAME="new_ent">To add an expression to the Watch Window</A>, simply enter |
| the expression into the entry at the bottom of the window and press return |
| or click the "Add Watch" button. The expression is validated and added to the |
| Watch Window Display. |
| |
| <P><A NAME="new_src">To add an expression to the Watch Window from the |
| <A HREF="source.html">Source Window</A></A>, use the |
| "<A HREF="source.html#add_to_watch">Add to Watch</A>" option of the |
| <A HREF="source.html#display_popup">Source Window Pop-up Menu</A>.</P> |
| |
| <P>Any legal expression may be added to the Watch Window, which will |
| evaluate each of its expressions everytime the program runs. Be cautious |
| adding expressions which cause assignments, such as "<CODE>i++</CODE>".</P> |
| |
| <P>Adding a register to the Watch Window can be advantages when debugging |
| via a slow serial line. In this case, keeping the entire Register Window open |
| may be inefficient. Consider adding the register to the Watch Window. Simply |
| enter the name of the register preceded with a dollar sign ($) into the |
| Entry. For example, to watch the PC register, enter "<CODE>$pc</CODE>" into |
| the Watch Window Entry. The program counter is added to the Display.</P> |
| |
| <P><A NAME="new_cast">To cast pointers</A>, simply enter the cast into the |
| Watch Window Entry at the bottom of the window. Use the same syntax for the |
| cast that the source file uses. If the source file uses C, the a simple |
| cast of "<CODE>ptr</CODE>" of type "<CODE>void *</CODE>" can be cast to type |
| "<CODE>my_struct</CODE>" by entering "<CODE>(my_struct *) ptr</CODE>" into |
| the Entry.</P> |
| |
| <H3><A NAME="display">Watch Display</A></H3> |
| The Watch Window Display consists of a scrolled listbox which contains all |
| watch expressions, one per line. To use any of the functions of the Watch |
| Window, use the left mouse button to select any element from the Display. |
| |
| <P>Pointers, structures, and classes appear in the display with a small |
| exapansion box before their names. To <A NAME="display_deref">dereference |
| pointers</A> or <A NAME="display_struct">view the members of classes or |
| structures</A>, click the closed expansion box (which appears as a small |
| plus sign, "+") to "expand" the listing. The expansion box changes to a |
| minus sign, "-", indicating that the display is now open. Pointers, |
| structures and classes may be expanded recursively to allow multiple pointer |
| dereferences and embedded structure viewing. |
| |
| <P>The Locals Display updates as the trace buffer is navigated, highlighting |
| in blue those variables whose values have changed.</P> |
| |
| <P>The Watch Window will, by default, display all pointers in hexadecimal and all |
| other variables in decimal. To change the default display of variables, use the |
| "set output-radix" command in the console window. (Type "help set output-radix" in the |
| console window for help. To make this change permanent, it must be added to the user's |
| init file -- .gdbinit.) To change the display |
| format for a variable, select the Format option from either the Variable Menu or the |
| <A HREF="#display_popup">Watch Pop-up Menu</A>. |
| <BR> |
| |
| <H4><A NAME="display_popup">Watch Pop-up Menu</A></H4> |
| The Watch Pop-up Menu provides quick access to the functions of the Watch Window. |
| To use the Locals Pop-up Menu, first select an expression from the Display (by |
| clicking the left mouse button on it) and click the right mouse button, choosing |
| from the pop-up: |
| <DL> |
| <DT>Format |
| <DD>Change the display format of the expression. The expression may be |
| displayed as: |
| <DL> |
| <DT>Hex |
| <DD>hexadecimal (base 16) |
| <DT>Decimal |
| <DD>decimal (base 10) |
| <DT>Binary |
| <DD>binary (base 2) |
| <DT>Octal |
| <DD>octal (base 8) |
| </DL> |
| </DL> |
| </BODY> |
| </HTML> |