GNU Info

(gcc-295.info)All Debuggers

---

Next: DBX Options Up: Debugging Info

---

Enter node , (file) or (file)node

Macros Affecting All Debugging Formats
--------------------------------------

   These macros affect all debugging formats.

`DBX_REGISTER_NUMBER (REGNO)'
     A C expression that returns the DBX register number for the
     compiler register number REGNO.  In simple cases, the value of this
     expression may be REGNO itself.  But sometimes there are some
     registers that the compiler knows about and DBX does not, or vice
     versa.  In such cases, some register may need to have one number in
     the compiler and another for DBX.

     If two registers have consecutive numbers inside GNU CC, and they
     can be used as a pair to hold a multiword value, then they *must*
     have consecutive numbers after renumbering with
     `DBX_REGISTER_NUMBER'.  Otherwise, debuggers will be unable to
     access such a pair, because they expect register pairs to be
     consecutive in their own numbering scheme.

     If you find yourself defining `DBX_REGISTER_NUMBER' in way that
     does not preserve register pairs, then what you must do instead is
     redefine the actual register numbering scheme.

`DEBUGGER_AUTO_OFFSET (X)'
     A C expression that returns the integer offset value for an
     automatic variable having address X (an RTL expression).  The
     default computation assumes that X is based on the frame-pointer
     and gives the offset from the frame-pointer.  This is required for
     targets that produce debugging output for DBX or COFF-style
     debugging output for SDB and allow the frame-pointer to be
     eliminated when the `-g' options is used.

`DEBUGGER_ARG_OFFSET (OFFSET, X)'
     A C expression that returns the integer offset value for an
     argument having address X (an RTL expression).  The nominal offset
     is OFFSET.

`PREFERRED_DEBUGGING_TYPE'
     A C expression that returns the type of debugging output GNU CC
     should produce when the user specifies just `-g'.  Define this if
     you have arranged for GNU CC to support more than one format of
     debugging output.  Currently, the allowable values are `DBX_DEBUG',
     `SDB_DEBUG', `DWARF_DEBUG', `DWARF2_DEBUG', and `XCOFF_DEBUG'.

     When the user specifies `-ggdb', GNU CC normally also uses the
     value of this macro to select the debugging output format, but
     with two exceptions.  If `DWARF2_DEBUGGING_INFO' is defined and
     `LINKER_DOES_NOT_WORK_WITH_DWARF2' is not defined, GNU CC uses the
     value `DWARF2_DEBUG'.  Otherwise, if `DBX_DEBUGGING_INFO' is
     defined, GNU CC uses `DBX_DEBUG'.

     The value of this macro only affects the default debugging output;
     the user can always get a specific type of output by using
     `-gstabs', `-gcoff', `-gdwarf-1', `-gdwarf-2', or `-gxcoff'.