IV91637: INVALID "THE STATEMENT IS UNREACHABLE" -QINFO MESSAGE

XL C/C++ for AIX, V13.1.3.3 Fix Pack (December 2016)
XL C/C++ for AIX, V13.1.3.4 Fix Pack (April 2017)
XL C/C++ for AIX, V13.1.3.5 Fix Pack (July 2018)
XL C/C++ for AIX, V13.1.3.6 Fix Pack (May 2019)

APAR status

• Closed as program error.

Error description

• The -qinfo=rea diagnostic for unreachable code is incorrectly
  flagging a reachable statement.  The issue appears related to
  exception handling code flow.
  
  
  
     === TEST CASE ===
  
  #include <iostream>
  using namespace std;
  
  void funcThatThrows()
  {
     throw 25;
  }
  
  int main ()
  {
     try
     {
        funcThatThrows();
        return 1;
     }
     catch (int e)
     {
        if (e > 100)
           throw;
     }
  
     cout << "reachable" << endl;
     return 0;
  }
  
  
  $ xlC -qinfo=rea apar.cpp
  "test.cpp", line 22.24: 1540-5340 (I) The statement is
  unreachable.
  $ ./a.out
  reachable
  $
  

Local fix

Problem summary

• PROBLEM DESCRIPTION:
  The compiler was missing the fact that a function call in a try
  block may throw and bypass a return statement in the try block
  after the function call.
  
  USERS AFFECTED:
  Users of option -qinfo=rea to get compiler warnings of
  unreachable statements.
  

Problem conclusion

• The problem has been solved.
  

Temporary fix

Comments

APAR Information

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

  IV86551

• 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