How to use the #pragma message to generate user-defined warning messages in Visual C++ (155196)

The information in this article applies to:

Microsoft Visual C++ 1.0
Microsoft Visual C++ 1.5
Microsoft Visual C++ 1.51
Microsoft Visual C++ 1.52
Microsoft Visual C++ 2.0
Microsoft Visual C++ 2.1
Microsoft Visual C++ 2.2
Microsoft Visual C++ 4.0
Microsoft Visual C++ 4.1
Microsoft Visual C++, 32-bit Enterprise Edition 4.2
Microsoft Visual C++, 32-bit Enterprise Edition 5.0
Microsoft Visual C++, 32-bit Enterprise Edition 6.0
Microsoft Visual C++, 32-bit Professional Edition 4.2
Microsoft Visual C++, 32-bit Professional Edition 5.0
Microsoft Visual C++, 32-bit Professional Edition 6.0
Microsoft Visual C++, 32-bit Learning Edition 6.0

This article was previously published under Q155196

SUMMARY

In some instances, you may find it advantageous to have the compiler generate user-defined warning messages such as the following:

collisions.cpp(1) : Warning Msg: Need to do 3-D collision checking

When such a warning is generated by the compiler and displayed in the Developer Studio's Output window, you can double-click on the warning message to get to the line of code with the message.

MORE INFORMATION

The following code illustrates how to use the #pragma message to force the compiler to generate the above warning message. Note the spacing around the colons in the third #define statement. The Visual Workbench that ships with the 16-bit versions of Visual C++ does not recognize a double-click in the Output window unless the proper spacing exists between the colons.

// collisions.h
#define __STR2__(x) #x
#define __STR1__(x) __STR2__(x)
#define __LOC__ __FILE__ "("__STR1__(__LINE__)") : Warning Msg: "

// collisions.cpp
#pragma message(__LOC__"Need to do 3D collision testing")

REFERENCES

For additional information concerning the #pragma message directive, see the Visual C++ Help file; Search on: "message (pragma directive)."

For additional information concerning the __FILE__ and __LINE__ predefined macros, see the Visual C++ Help file; Search on: "predefined macros," Topic: "Preprocessor Reference," and click on "ANSI."

Modification Type:	Major	Last Reviewed:	6/2/2005
Keywords:	kberrmsg kbinfo kbhowto kbide kbLangC KB155196 kbAudDeveloper