More thoughts about ioctl and kernel ABIs in general

[H. Peter Anvin]

I wanted to show a *very* simple example... this is a Coccinelle script 
that mangles the kernel termios files to change the structure names, 
delete the ktermios structure (which should never have been included in 
uapi; I'm going to submit a patch to the kernel to fix that), tack 
underscores in front of some symbols, add __extension__ to anonymous 
struct and union members, and put some definitions under #ifdef __USE_MISC.

The latter rule does cause a whole lot of #ifdef ... #endif #ifdef .. 
#endif, but this can be handled with a simple postprocessing script like 
the attached Perl script.

	-hpa


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@ struct_add_kernel @
identifier os =~ "^termio";
fresh identifier ns = "__kernel_" ## os;
@@

- struct os
+ struct ns

@ struct_add_kernel_def @
identifier os =~ "^termio";
fresh identifier ns = "__kernel_" ## os;
@@

- struct os
+ struct ns
{ ... }

@ struct_delete @
identifier sname =~ "^ktermios$";
@@
- struct sname { ... };

@ double_underscore @
identifier ob =~ "^(B[0-9]+|BOTHER|NCC|NCCS)$";
fresh identifier nb = "__" ## ob;
expression E;
@@

- #define ob E
+ #define nb E

@ double_underscore_use @
identifier double_underscore.ob;
fresh identifier nb = "__" ## ob;
@@

- ob
+ nb

@ use_misc @
identifier x =~ "^(EXT[AB]|ADDRB|CMSPAR|CRTSCTS|IBSHIFT)$";
expression E;
@@

+#ifdef __USE_MISC
#define x E
+#endif

@ anon_field_hasid @
identifier id;
type T;
attribute name __extension__;
@@
(
struct id {
       ...
- T;
+ __extension__ T;
       ...
}
|
union id {
       ...
- T;
+ __extension__ T;
       ...
}
)

@ anon_field_noid @
type T;
attribute name __extension__;
@@
(
struct {
       ...
- T;
+ __extension__ T;
       ...
}
|
union {
       ...
- T;
+ __extension__ T;
       ...
}
)