BC Makes Smaller EXE than Make EXE File Using .LIB; e.g. Mouse (28963)

SUMMARY

Object (.OBJ) files linked to .LIB libraries from the DOS command line may produce a smaller .EXE file than will be created with the Make EXE File... option if you invoked QB.EXE Version 4.00 or 4.00b with the /L option to use a Quick library (.QLB) file.

If the BC compiler options are the same for the two methods of making the .EXE file, then the .EXE size difference depends on the syntax of the LINK statement used to create the executable program, as follows:

If the .LIB file is specified in the .OBJ list (the first argument) for LINK.EXE, then ALL routines in the .LIB file are linked into the .EXE.

When you invoke QB.EXE Version 4.00 or 4.00b with the /L option to load a Quick library, the Make EXE File... option automatically puts the .LIB (that matches the Quick library) in the .OBJ list, often making a larger .EXE.
If the .LIB file is specified in the .LIB list (the fourth parameter) for LINK.EXE, then just the external routines called from programs in the .OBJ list are pulled into the .EXE file from the .LIB file.

QB.EXE Version 4.50 has been enhanced to do this automatically when you invoke with /L to load a Quick library and you choose the Make EXE File... option. This can make a smaller .EXE file if there are uncalled routines in the .LIB file.

This information about LINK.EXE applies to QuickBasic Versions 4.00, 4.00b, and 4.50 and the Basic Compiler Versions 6.00 and 6.00b for MS-DOS and OS/2.

MORE INFORMATION

The example program below, MOUS.BAS, uses the statement CALL INT86old to access the Microsoft Mouse through interrupt 51 (33 hex). INT86old is an external routine contained in QB.LIB. Programs that use CALL INT86old must be linked with the file QB.LIB (or run inside the QuickBasic editor with QB /L QB.QLB).

When the program MOUS.BAS is loaded into the QuickBasic Version 4.00 or 4.00b editor and the Make EXE File... option is selected from the RUN menu, the following LINK command is issued:

   LINK /EX /NOE MOUS+QB.LIB, C:MOUS.EXE, NUL,;

Pressing the F4 key in the QB.EXE editor lets you toggle to view this command line because the editor covers the output screen by default after Make EXE.

The resulting executable file (MOUS.EXE) has a size of 4213 bytes. However, if the same program is compiled from the DOS command line and then linked with the following command, the resulting executable file has a size of only 3925 bytes:

   BC MOUS;
   LINK /EX /NOE MOUS, C:MOUS.EXE, NUL, QB.LIB,;

The size difference occurs because when the .LIB library files are specified as the fourth parameter in the LINK statement (as in the second LINK command above) the linker can be more "granular" than when the .LIB library files are included in the first parameter. Granularity refers to the ability of LINK.EXE to link in only those modules within the library file(s) that are actually referenced by the program. For example, if the library is composed of two object files, SUB1.OBJ and SUB2.OBJ, but only one of them is ever CALLed by the Basic program, then only the one called will be linked into the EXE file.

The following is the reason that Make EXE File... option in QB.EXE Version 4.00 and 4.00b puts the .LIB file (which correspond to a loaded Quick library) in the first parameter of the LINK syntax: the resulting EXE will more closely resemble the program as it executes inside the QuickBasic editor.

By popular request, the Make EXE File... option was changed in QB.EXE Version 4.50 to put the .LIB file in the library area for better granularity (i.e., smaller .EXE files).

The following program CALLs the INT86old routine for drawing in high-resolution graphics mode with the mouse:

   DECLARE SUB MOUS (m0%, m1%, m2%, m3%)
   DEFINT A-Z
   SCREEN 2
   m0 = 0: m1 = 0: m2 = 0: m3 = 0: oldx = 0: oldy = 0
   CALL MOUS(m0, m1, m2, m3)
      'initialize mouse
   m0 = 1
   INPUT "press any key to turn on mouse cursor:", x
   CALL MOUS(m0, m1, m2, m3)
   'turn on mouse cursor
   END
   SUB MOUS (m0, m1, m2, m3) STATIC
   DIM regs(7)
           regs(0) = m0: regs(1) = m1: regs(2) = m2: regs(3) = m3
           CALL int86old(51, regs(), regs())
           m0 = regs(0): m1 = regs(1): m2 = regs(2): m3 = regs(3)
   END SUB

The interrupt 51 (i.e., 33 hex) for Microsoft Mouse Version 6.00 (and later) is documented in the following book: "Advanced MS-DOS Programming," Second Edition, by Ray Duncan (published by Microsoft Press, 1988) on Pages 593-611. (The first edition published in 1986 did not document the mouse interrupt.)

More information regarding making mouse calls from Basic can be found in the "Mouse Programmer's Reference Guide," which can be ordered from Microsoft Customer Service by calling (206) 882-8088.