Re: Inserting new parameter in gcc

["Manuel López-Ibáñez" <lopezibanez at gmail dot com>]

Just to complete this discussion, the syntax of the *.opt files is
(almost exactly) mapped by the gen-*.awk scripts into flags that are
defined in the file gcc/opts.h. This file contains some comments about
these flags:

#define CL_PARAMS               (1 << 18) /* Fake entry.  Used to
display --param info with --help.  */
#define CL_WARNING		(1 << 19) /* Enables an (optional) warning message.  */
#define CL_OPTIMIZATION		(1 << 20) /* Enables an (optional) optimization.  */
#define CL_TARGET		(1 << 21) /* Target-specific option.  */
#define CL_COMMON		(1 << 22) /* Language-independent.  */

#define CL_MIN_OPTION_CLASS	CL_PARAMS
#define CL_MAX_OPTION_CLASS	CL_COMMON

/* From here on the bits describe attributes of the options.
   Before this point the bits have described the class of the option.
   This distinction is important because --help will not list options
   which only have these higher bits set.  */

#define CL_DISABLED		(1 << 23) /* Disabled in this configuration.  */
#define CL_REPORT		(1 << 24) /* Report argument with -fverbose-asm  */
#define CL_JOINED		(1 << 25) /* If takes joined argument.  */
#define CL_SEPARATE		(1 << 26) /* If takes a separate argument.  */
#define CL_REJECT_NEGATIVE	(1 << 27) /* Reject no- form.  */
#define CL_MISSING_OK		(1 << 28) /* Missing argument OK (joined).  */
#define CL_UINTEGER		(1 << 29) /* Argument is an integer >=0.  */
#define CL_UNDOCUMENTED		(1 << 30) /* Do not output with --help.  */

Juan Luis, if you really want to contribute in this area, I would
suggest to add a sentence to the *.opt files and the scripts pointing
to gcc/opts.h and then improve the documentation there to mention the
original syntax and how it maps into the flags (although in most cases
it is pretty obvious: RejectNegative -> CL_REJECT_NEGATIVE).

Nevertheless, this doesn't mean we are not open to suggestions on how
to improve the current system.

Thanks,

Manuel.