HP gnu source-level debugger 5992-4701 manual Examining the Symbol Table

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 26)), or by one of the file-management commands (see “Commands to specify files” (page 125)).

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 84)). 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.
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 83).
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'.
ptype expr, ptype	Print a description of the type of expression
	expr. ptype differs from whatis by printing a

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