[RTEMS Project] #3384: Change int32_t to int

[RTEMS trac]

#3384: Change int32_t to int
------------------------------+-----------------------------
  Reporter:  Sebastian Huber  |      Owner:  Sebastian Huber
      Type:  enhancement      |     Status:  assigned
  Priority:  normal           |  Milestone:  5.1
 Component:  tool/gcc         |    Version:
  Severity:  normal           |   Keywords:
Blocked By:                   |   Blocking:
------------------------------+-----------------------------
 Common systems like Linux and FreeBSD define int32_t to int. This means a
 lot of third party code works well in these cases:
 {{{
 #include <stdint.h>

 void f(int32_t);

 void f(int);

 void g(int32_t *);

 void h(void)
 {
         int i;
         g(&i);
 }
 }}}

 On RTEMS you get however in C
 {{{
 test.c:5:6: error: conflicting types for 'f'
  void f(int);
       ^
 test.c:3:6: note: previous declaration of 'f' was here
  void f(int32_t);
       ^
 test.c: In function 'h':
 test.c:12:4: warning: passing argument 1 of 'g' from incompatible pointer
 type [-Wincompatible-pointer-types]
   g(&i);
     ^
 test.c:7:6: note: expected 'int32_t * {aka long int *}' but argument is of
 type 'int *'
  void g(int32_t *);
 }}}
 and C++
 {{{
 test.c: In function 'void h()':
 test.c:12:4: error: invalid conversion from 'int*' to 'int32_t* {aka long
 int*}' [-fpermissive]
   g(&i);
     ^~
 test.c:7:6: note:   initializing argument 1 of 'void g(int32_t*)'
  void g(int32_t *);
       ^
 }}}
 This is due to a Newlib speciality which uses long for int32_t if long is
 a 32-bit type.  To ease the use of third party software in RTEMS we should
 override this option and use int for int32_t just like the standard host
 operating systems (e.g. Linux and FreeBSD).  Only a small GCC patch is
 required to do this:
 {{{
 diff --git a/gcc/config/rtems.h b/gcc/config/rtems.h
 index 439199d4cbb..9b1408efe6f 100644
 --- a/gcc/config/rtems.h
 +++ b/gcc/config/rtems.h
 @@ -48,3 +48,7 @@
   -latomic -lc -lgcc --end-group %{!qnolinkcmds: -T linkcmds%s}}}"

  #define TARGET_POSIX_IO
 +
 +/* Use int for int32_t (see stdint-newlib.h).  */
 +#undef STDINT_LONG32
 +#define STDINT_LONG32 0
 }}}

--
Ticket URL: <http://devel.rtems.org/ticket/3384>
RTEMS Project <http://www.rtems.org/>
RTEMS Project