PRB: Error 2065: 'jmp_buf' : Undeclared Identifier

The information in this article applies to:

• Microsoft C/C++ for MS-DOS, version 7.0
• Microsoft Visual C++ for Windows, versions 1.0, 1.5, 1.51, and 1.52

SYMPTOMS

When compiling a C++ program that uses the setjmp and longjmp functions with Microsoft C++, the following errors may be generated:

   error C2065: 'jmp_buf' : undeclared identifier
   error C2065: 'setjmp' : undeclared identifier
   error C2065: 'longjmp' : undeclared identifier
   error C2064: term does not evaluate to a function

CAUSE

The setjmp, longjmp, and jmp_buf identifiers are declared in the SETJMP.H header file. These declarations are not included if the __cplusplus symbol is defined.

MORE INFORMATION

The symbol __cplusplus is defined when a C++ program is compiled. Because setjmp and longjmp are not supported in C++ programs, the declarations are nested in an #ifndef block, which causes the declarations to be skipped if the __cplusplus symbol is defined.

Although setjmp and longjmp can be used in a C++ program, their use is discouraged. If a jump takes your program out of the function block in which a class was declared, the destructors for the classes will not be called. This will have deleterious effects.