IV39332: INCORRECT WARNING ON RESTRICT POINTER TYPE

XL C/C++ for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C for AIX Fix Pack 15 (August 2013 PTF) for 11.1
XL C/C++ for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 17 (February 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C/C++ for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 21 (April 2015 PTF) for 11.1
XL C/C++ for AIX Fix Pack 22 (September 2015 PTF) for 11.1
XL C for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 23 (March 2016 PTF) for 11.1
XL C for AIX Fix Pack 24 (September 2016 PTF) for 11.1
XL C/C++ for AIX Fix Pack 24 (September 2016 PTF) for 11.1
XL C for AIX Fix Pack 16 (November 2013 PTF) for 11.1
XL C for AIX Fix Pack 18 (May 2014 PTF) for 11.1
XL C for AIX Fix Pack 19 (August 2014 PTF) for 11.1
XL C for AIX Fix Pack 20 (November 2014 PTF) for 11.1
XL C for AIX Fix Pack 22 (September 2015 PTF) for 11.1

APAR status

• Closed as program error.

Error description

• The testcase xlc_typedef_restrict.c below shows C compiler
  warning about incorrect usage of the restrict keyword, while
  the usage is correct. C++ compiler takes it happily with no
  warning message.
  
  ===== TESTCASE:
  $cat xlc_typedef_restrict.c
  #include <stdlib.h>
  
  struct foobar { void (*fp)(void *); };
  struct baz { const struct foobar *p; };
  struct foo { int a, b;  struct baz c; };
  typedef struct foo *bar;
  
  void func(struct foo* restrict p, struct foo* restrict q) {}
  
  void funk(bar restrict p, bar restrict q) {}
  
  int main()
  {
          bar p,q;
          bar restrict l;
          struct foo* restrict m;
          func(p,q);
          funk(p,q);
  }
  
  xlc  -c xlc_typedef_restrict.c
  "xlc_typedef_restrict.c", line 10.11: 1506-404 (W) restrict can
  only qualify a pointer type.
  "xlc_typedef_restrict.c", line 10.27: 1506-404 (W) restrict can
  only qualify a pointer type.
  "xlc_typedef_restrict.c", line 15.9: 1506-404 (W) restrict can
  only qualify a pointer type.
  

Local fix

• Change
  struct foobar { void (*fp)(void *); };
  
  To
  struct foobar { void (**fp)(void); };
  

Problem summary

• PROBLEM DESCRIPTION: Incorrect diagnose message of restrict
  pointer.
  
  USERS AFFECTED: Programs using restrcit qualifier on a
  struct/union pointer which contain function pointer member.
  

Problem conclusion

• Problem is fixed. The warning message is not emitted. Apply
  provided service.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  LI77567 IV49626 LI77612

Fix information

• Fixed component name

  XL C FOR AIX

• Fixed component ID

  5724X1200

Applicable component levels