FIX: /Og Causes C1001 Traversing Non-Trivial List of Pointers

• The C/C++ Compiler (CL.EXE) included with:

      - Microsoft Visual C++, 32-bit Editions, version 5.0
  

SYMPTOMS

Compiling code similar to that 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

In the sample below, initializing all the local integers to known values, instead of leaving them uninitialized, will allow the code below to compile without generating the C1001 error.

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:

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

MORE INFORMATION

Sample

   // compile options: /Og /c
   struct B;
   struct A {
      B * pB;
   };
   struct B {
      A * pA;
      B * pBnext;
      B * pBb;
   } ;
   void f() {
      int i;    // initialize for workaround
      int j;    // initialize for workaround
      int k = 0;
      B * pB1;
      B * pB2 = 0;
      B * pB3;
      B * rgpB[2];
      int rgi[2];
      while(1)
      {
         rgi[i] = k++;
         pB2 = pB2->pBb;
         rgpB[k] = pB2;
         j = k++;
         pB3 = rgpB[j];
         pB1 = pB3->pA->pB;
         while (pB1)
            pB1 = pB1->pBnext;
      }
   }