BUG: Evaluating _pascal Functions Can Give Erroneous CXX0039

MS-DOS         | WINDOWS

The information in this article applies to:

• Microsoft Codeview for MS-DOS, versions 4.0, 4.01, and 4.1
• Microsoft Codeview for Windows, versions 4.0, 4.01, and 4.1

SYMPTOMS

Evaluating functions declared with the _pascal calling convention in the Codeview command window using either the C or C++ Expression Evaluator can cause the following error:

      CXX0039: Error Symbol is ambiguous

RESOLUTION

Avoid using all uppercase letters in functions declared with the _pascal calling convention. Then, turn on Codeview's case sensitivity before evaluating these functions in the command window.

In the case of exported functions mentioned above, be sure to use the fully decorated name in the .DEF file. If you are unsure what they are, use the linker /MAP option to have the linker generate a .map file. This file contains the symbol names after they have been decorated.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft 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 sample code listed below can be used to illustrate the problem. To do this, build a debug version of the program, start a debugging session in Codeview, and enter the following commands in the Codeview command window:

t2                      trace into main
oc+                     turn on case sensitivity
? FUNC2()               the CXX0039 error is generated.
? Func1()               no error; the function is evaluated

oc-
? Func1()               the error is generated

? Func1                 always works
? FUNC2                 always works

Sample Code

/* Compile options needed:   /Zi /Od  */
#include <stdio.h>

void _pascal Func1(void)

    printf("First _pascal function.\n");

void _pascal FUNC2(void)

    printf("Second _pascal function.\n");

void main(void)

    printf("Hello World.\n");