Q173025: FIX: /Og Causes C1001 with Member Lookup in an Infinite Loop

Article: Q173025
Product(s): Microsoft C Compiler
Version(s): WINNT:5.0
Operating System(s): 
Keyword(s): kberrmsg kbCompiler kbVC500bug kbVS97sp2fix
Last Modified: 17-JUL-2001

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The information in this article applies to:

- The C/C++ Compiler (CL.EXE), included with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
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SYMPTOMS
========

Compiling code similar to the code in the sample below may cause the following
error to be generated:

  fatal error C1001: INTERNAL COMPILER ERROR
  (compiler file 'E:\utc\src\\P2\main.c', line 379)

RESOLUTION
==========

This internal compiler error can be avoided by using the volatile keyword. In
the example below, declaring the local variable, pB, as volatile B* pB instead
of B* pb, will work around the problem.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been fixed in Visual Studio 97 Service
Pack 3.

For more information, please see the following article in the Microsoft Knowledge
Base:

  Q170365 INFO: Visual Studio 97 Service Packs - What, Where, and Why

MORE INFORMATION
================

Sample
------

     // compile options: /Og /c
     struct A {
        int i;
     };
     struct B {
        struct A * pA ;
        int j ;
     };
     void f()
     {
        //volatile //uncomment the volatile keyword for workaround
        B * pB =0;
        for (;;)
        {
           pB->j = pB->pA->i++ ;
        }
     }

Additional query words: ICE

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Keywords          : kberrmsg kbCompiler kbVC500bug kbVS97sp2fix 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : WINNT:5.0
Issue type        : kbbug
Solution Type     : kbfix

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