Debugging with GDB Manual HP WDB v6.3 (5900-2180, August 2012)

working directory. '$cwd' is not the same as '.'. The former tracks
the current working directory as it changes during your GDB
session, while the latter is immediately expanded to the current
directory at the time you add an entry to the source path.
directory Reset the source path to empty again. This requires confirmation
from the user.
show directories Print the source path and display the directories it contains.
If your source path is cluttered with directories that are no longer of interest, GDB can end up
detecting the wrong version of the source. To correct this situation, follow these steps:
1. Use directory with no arguments to reset the source path to empty.
2. Use directory with suitable arguments to reinstall the directories you want in the source
path. You can add all the directories in one command.
7.4 Source and machine code
You can use the command info line to map source lines to program addresses (and vice versa),
and the command disassemble to display a range of addresses as machine instructions. When
run under GNU Emacs mode, the info line command causes the arrow to point to the line
specified. Also, info line prints addresses in symbolic form as well as hex.
info line linespec Print the starting and ending addresses of the compiled code for
source line linespec. You can specify source lines in any of the
ways understood by the list command (see “Printing source lines”
(page 59)).
For example, we can use info line to discover the location of the object code for the first line
of function.
m4_changequote:
((gdb)) info line m4_changequote
Line 895 of "builtin.c" starts at pc 0x634c and ends at 0x6350.
We can also inquire (using *addr as the form for linespec) what source line covers a particular
address. For example,
((gdb)) info line *0x63ff
Line 926 of "builtin.c" starts at pc 0x63e4 and ends at 0x6404.
After info line, the default address for the x command is changed to the starting address of
the line, so that 'x/i' is sufficient to begin examining the machine code (see Section 8.5 (page 66)).
Also, this address is saved as the value of the convenience variable $_ (see Section 8.9 (page 73)).
disassemble This specialized command dumps a range of memory as machine instructions.
The default memory range is the function surrounding the program counter of
the selected frame. A single argument to this command is a program counter
value; GDB dumps the function surrounding this value. Two arguments specify
a range of addresses (first inclusive, second exclusive) to dump.
The following example shows the disassembly of a range of addresses of HP PA-RISC 2.0 code:
((gdb)) disas 0x32c4 0x32e4
Dump of assembler code from 0x32c4 to 0x32e4:
0x32c4 <main+204>: addil 0,dp
0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26
0x32cc <main+212>: ldil 0x3000,r31
0x32d0 <main+216>: ble 0x3f8(sr4,r31)
0x32d4 <main+220>: ldo 0(r31),rp
0x32d8 <main+224>: addil -0x800,dp
0x32dc <main+228>: ldo 0x588(r1),r26
7.4 Source and machine code 61