BUG: Incorrect Use of #pragma Pack Causes C1001 Errors

• The C/C++ Compiler (CL.EXE) included with: - Microsoft Visual C++, 32-bit Edition, versions 1.0, 2.0, 4.0, 4.1,

       4.2, 5.0
  

SYMPTOMS

When compiling code that uses #pragma pack() to pop an ID that has not been pushed after successfully popping an ID that was pushed, the compilers listed above will generate:

   fatal error C1001: INTERNAL COMPILER ERROR

    (compiler file 'msc1.cpp', line 902)
    Please choose the Technical Support command on the Visual C++
    Help menu, or open the Technical Support help file for more information

RESOLUTION

Pop only IDs that have been previously pushed onto the compiler's internal stack.

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following sample code demonstrates the bug:

Sample Code

   /* packfail.c

   Compile options needed: none
   */

   #pragma pack(push, a)
   #pragma pack(push, b, 4)
   #pragma pack(pop, b)
   #pragma pack(pop, value)