Chapter 1 LabWindows/CVI Compiler
LabWindows/CVI Programmer Reference Manual 1-4
©
National Instruments Corporation
At this time, not all these qualifiers work in all external compilers. The LabWindows/CVI
cvidef.h include file defines the following macros, which are designed to work in each
external compiler.
DLLIMPORT
DLLEXPORT
An import qualifier informs the compiler that the symbol is defined in a DLL. Declarations
of variables imported from a DLL require import qualifiers, but function declarations do not.
An export qualifier is relevant only in a project for which the target type is Dynamic Link
Library. The qualifier can be on the declaration or definition of the symbol, or both. The
qualifier instructs the linker to include the symbol in the DLL import library.
C++ Comment Markers
You can use double slashes (//) to begin a comment. The comment continues until the end of
the line.
Duplicate Typedefs
The LabWindows/CVI compiler does not report an error on multiple definitions of the same
typedef identifier, as long as the definitions are identical.
Structure Packing Pragma (Windows 3.1 and Windows 95/NT Only)
The pack pragma can be used within LabWindows/CVI to specify the maximum alignment
factor for elements within a structure. For example, assume the following structure definition:
struct t {
double d1;
char charVal;
short shortVal;
double d2;
};
If the maximum alignment is 1, the compiler can start the structure on any 1-byte boundary
and inserts no gaps between the structure elements.
If the maximum alignment is 8, the compiler must start the structure on an 8-byte boundary,
place shortVal on a 2-byte boundary, and place d2 on an 8-byte boundary.

00ProRef.book : 06chap01.fm Page 4 Monday, March 9, 1998 3:23 PM