IJ46603: QROPTR CAUSING LINKER ERROR: CSECTS OVERLAP

APAR status

• Closed as program error.

Error description

• When using the -qroptr compiler option to place constant
  pointers in read-only memory, the presence of static const
  global variables may encounter a linker error:
  
  
  $ xlc apar.c -qroptr
  ld: 0711-552 SEVERE ERROR: Object /tmp/15663144_0.o:
          Csects with symbol numbers 14 and 18 overlap.
  $
  
  
  
     === TEST CASE ===
  
  typedef struct mystruct1
  {
    unsigned char    **val;
  } mystruct1;
  
  typedef struct mystruct2
  {
    mystruct1  *val;
  } mystruct2;
  
  typedef struct mystruct3
  {
    mystruct2    *val;
  } mystruct3;
  
  static const unsigned char* myconst1[] = {
      (unsigned char*)0};
  
  static const mystruct1 myconst2[] = {
  { (unsigned char **)myconst1},
    { (unsigned char **)0}};
  
  static const mystruct2 myconst3[] = {
  { (mystruct1 *)myconst2},
  { (mystruct1 *)0}}
  ;
  
  const mystruct3 myconst4[] =
  {
    { (mystruct2 *)myconst3},
    { (mystruct2 *)0 }
  };
  

Local fix

• - Remove the -qroptr option
  - Remove either 'static' or 'const' from affected symbol
  

Problem summary

• PROBLEM DESCRIPTION:
  The compiler is ignoring static variables if there is no code
  that references it; this then causes symbol mismatch when
  generating the object symbol table.
  
  USERS AFFECTED:
  Users of -qroptr with code that contains static const objects.
  

Problem conclusion

• The symbol mismatch issue was resolved.
  

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:

Fix information

• Fixed component name

  XL C/C++ FOR AI

• Fixed component ID

  5725C7200

Applicable component levels