FIX: C1001: Extern in Function Call or Bad Type in Prototype

• The Microsoft C/C++ Compiler (CL.EXE) included with: - Microsoft Visual C++, 32-bit Edition, versions 4.0, 4.1, 4.2

SYMPTOMS

When using extern in a function call, the compiler generates an Internal Compiler Error (ICE). A syntax error should be generated instead.

When specifying an illegal type in a function prototype within a function, the compiler generates an ICE. A syntax error should be generated instead.

Both of the above situations result in the following error message when using Visual C++ 4.0:

   fatal error C1001: INTERNAL COMPILER ERROR
   (compiler file 'msc1.cpp', line 899)

   fatal error C1001: INTERNAL COMPILER ERROR
   (compiler file 'msc1.cpp', line 1090)

   fatal error C1001: INTERNAL COMPILER ERROR
   (compiler file 'msc1.cpp', line 1089)

RESOLUTION

Do not use extern in a function call.

Specify a legal type in the argument list of the function prototype.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++ version 5.0.

MORE INFORMATION

Sample Code

   /* Compile options needed: none
   */

   //Code sample 1
   int func(int);

   void main () {
      extern func(1);   //C1001 (ICE) on this line; "extern" is illegal
   }

   //Code sample 2
   int func(int);

   void main () {
      extern int func(1);  //C1001 (ICE); "1" is an illegal type
   }

Keywords          : CPPIss vcbuglist400 vcfixlist500 kbprg
Version           : 4.0 4.1 4.2
Platform          : NT WINDOWS
Issue type        : kbbug
Solution Type     : kbfix