GDB allows you to express the constants of Modula-2 in the following
ways:
Integer constants are simply a sequence of digits. When used in an
expression, a constant is interpreted to be type-compatible with the
rest of the expression. Hexadecimal integers are specified by a
trailing `H', and octal integers by a trailing `B'.
Floating point constants appear as a sequence of digits, followed by a
decimal point and another sequence of digits. An optional exponent can
then be specified, in the form `E[+|-]nnn', where
`[+|-]nnn' is the desired exponent. All of the
digits of the floating point constant must be valid decimal (base 10)
digits.
Character constants consist of a single character enclosed by a pair of
like quotes, either single (') or double ("). They may
also be expressed by their ordinal value (their ASCII value, usually)
followed by a `C'.
String constants consist of a sequence of characters enclosed by a
pair of like quotes, either single (') or double (").
Escape sequences in the style of C are also allowed. See C Constants, for a brief explanation of escape
sequences.
Enumerated constants consist of an enumerated identifier.
Boolean constants consist of the identifiers TRUE and
FALSE.
Pointer constants consist of integral values only.
Debugging with GDB