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Chapter 1

LabWindows/CVI Compiler

LabWindows/CVI Programmer Reference Manual

1-4

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 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.

You can use double slashes (//) to begin a comment. The comment continues until the end of 
the line.

The LabWindows/CVI compiler does not report an error on multiple definitions of the same 
typedef identifier, as long as the definitions are identical.

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