Debugging with GDB Manual (5900-1473; WDB 6.2; January 2011)

10 Examining the Symbol Table
The commands described in this chapter allow you to inquire about the symbols (names
of variables, functions, and types) defined in your program. This information is inherent
in the text of your program and does not change as your program executes. GDB finds
it in your program's symbol table, in the file indicated when you started GDB (see
“Choosing files” (page 24)), or by one of the file-management commands (see
“Commands to specify files” (page 118)).
Occasionally, you may need to refer to symbols that contain unusual characters, which
GDB ordinarily treats as word delimiters. The most frequent case is in referring to static
variables in other source files (see “Program variables” (page 77)). File names are
recorded in object files as debugging symbols, but GDB would ordinarily parse a typical
file name, like 'foo.c', as the three words 'foo' '.' 'c'. To allow GDB to recognize
'foo.c' as a single symbol, enclose it in single quotes; for example,
p 'foo.c'::x
looks up the value of x in the scope of the file 'foo.c'.
info address symbol Describe where the data for symbol is stored.
For a register variable, this says which register it
is kept in. For a non-register local variable, this
prints the stack-frame offset at which the variable
is always stored.
NOTE: The contrast with 'print &symbol',
which does not work at all for a register variable,
and for a stack local variable prints the exact
address of the current instantiation of the variable.
This command is available only for applications
running on 11i v3 or later.
whatis expr Print the data type of expression expr. expr is
not actually evaluated, and any side-effecting
operations (such as assignments or function calls)
inside it do not take place. See “Expressions”
(page 76).
whatis Print the data type of $, the last value in the value
history.
ptype typename Print a description of data type typename.
typename may be the name of a type, or for C
code it may have the form 'class
class-name', 'struct struct-tag', 'union
union-tag' or 'enum enum-tag'.
108 Examining the Symbol Table