#### 18.21.2 Specific Options for DBX Output

These are specific options for DBX output.

Macro: DBX_DEBUGGING_INFO

  Define this macro if GCC should produce debugging output for DBX in response to the `-g` option.

Macro: XCOFF_DEBUGGING_INFO

  Define this macro if GCC should produce XCOFF format debugging output in response to the `-g` option. This is a variant of DBX format.

Macro: DEFAULT_GDB_EXTENSIONS

  Define this macro to control whether GCC should by default generate GDB’s extended version of DBX debugging information (assuming DBX-format debugging information is enabled at all). If you don’t define the macro, the default is 1: always generate the extended information if there is any occasion to.

Macro: DEBUG_SYMS_TEXT

  Define this macro if all `.stabs` commands should be output while in the text section.

Macro: ASM_STABS_OP

  A C string constant, including spacing, naming the assembler pseudo op to use instead of `"\t.stabs\t"` to define an ordinary debugging symbol. If you don’t define this macro, `"\t.stabs\t"` is used. This macro applies only to DBX debugging information format.

Macro: ASM_STABD_OP

  A C string constant, including spacing, naming the assembler pseudo op to use instead of `"\t.stabd\t"` to define a debugging symbol whose value is the current location. If you don’t define this macro, `"\t.stabd\t"` is used. This macro applies only to DBX debugging information format.

Macro: ASM_STABN_OP

  A C string constant, including spacing, naming the assembler pseudo op to use instead of `"\t.stabn\t"` to define a debugging symbol with no name. If you don’t define this macro, `"\t.stabn\t"` is used. This macro applies only to DBX debugging information format.

Macro: DBX_NO_XREFS

  Define this macro if DBX on your system does not support the construct ‘`xstagname`’. On some systems, this construct is used to describe a forward reference to a structure named tagname. On other systems, this construct is not supported at all.

Macro: DBX_CONTIN_LENGTH

  A symbol name in DBX-format debugging information is normally continued (split into two separate `.stabs` directives) when it exceeds a certain length (by default, 80 characters). On some operating systems, DBX requires this splitting; on others, splitting must not be done. You can inhibit splitting by defining this macro with the value zero. You can override the default splitting-length by defining this macro as an expression for the length you desire.

Macro: DBX_CONTIN_CHAR

  Normally continuation is indicated by adding a ‘`\`’ character to the end of a `.stabs` string when a continuation follows. To use a different character instead, define this macro as a character constant for the character you want to use. Do not define this macro if backslash is correct for your system.

Macro: DBX_STATIC_STAB_DATA_SECTION

  Define this macro if it is necessary to go to the data section before outputting the ‘`.stabs`’ pseudo-op for a non-global static variable.

Macro: DBX_TYPE_DECL_STABS_CODE

  The value to use in the “code” field of the `.stabs` directive for a typedef. The default is `N_LSYM`.

Macro: DBX_STATIC_CONST_VAR_CODE

  The value to use in the “code” field of the `.stabs` directive for a static variable located in the text section. DBX format does not provide any “right” way to do this. The default is `N_FUN`.

Macro: DBX_REGPARM_STABS_CODE

  The value to use in the “code” field of the `.stabs` directive for a parameter passed in registers. DBX format does not provide any “right” way to do this. The default is `N_RSYM`.

Macro: DBX_REGPARM_STABS_LETTER

  The letter to use in DBX symbol data to identify a symbol as a parameter passed in registers. DBX format does not customarily provide any way to do this. The default is `'P'`.

Macro: DBX_FUNCTION_FIRST

  Define this macro if the DBX information for a function and its arguments should precede the assembler code for the function. Normally, in DBX format, the debugging information entirely follows the assembler code.

Macro: DBX_BLOCKS_FUNCTION_RELATIVE

  Define this macro, with value 1, if the value of a symbol describing the scope of a block (`N_LBRAC` or `N_RBRAC`) should be relative to the start of the enclosing function. Normally, GCC uses an absolute address.

Macro: DBX_LINES_FUNCTION_RELATIVE

  Define this macro, with value 1, if the value of a symbol indicating the current line number (`N_SLINE`) should be relative to the start of the enclosing function. Normally, GCC uses an absolute address.

Macro: DBX_USE_BINCL

  Define this macro if GCC should generate `N_BINCL` and `N_EINCL` stabs for included header files, as on Sun systems. This macro also directs GCC to output a type number as a pair of a file number and a type number within the file. Normally, GCC does not generate `N_BINCL` or `N_EINCL` stabs, and it outputs a single number for a type number.