Q71422: Maintaining a Library with NMAKE
Article: Q71422
Product(s): Microsoft Programming Utilities
Version(s): 1.01,1.11,1.12,1.13,1.2,1.21,1.3,1.4
Operating System(s):
Keyword(s): kb16bitonly
Last Modified: 23-OCT-1999
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The information in this article applies to:
- Microsoft NMAKE Utility for MS-DOS, versions 1.01, 1.11, 1.12, 1.13, 1.2, 1.3, 1.4
- Microsoft NMAKE Utility for OS/2, versions 1.01, 1.11, 1.12, 1.13, 1.21
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SUMMARY
=======
NMAKE provides several features that ease the process of maintaining a library
by incrementally updating only the modules that change. With the $? special
macro and macro substitutions, the process involves only one call to LIB (the
library maintenance utility). The text below presents makefiles that illustrate
this procedure.
MORE INFORMATION
================
The sample makefiles below keep MYLIB.LIB up to date with respect to the four
object files listed in the OBJS macro. These object files can be based on C or
assembly language source files. You can extend the list of source-file types the
makefile supports by adding the appropriate inference rules to the description
file.
Sample makefile 1 includes the following line to maintain the library:
LIB MYLIB.LIB -+$(?: =-+);
The $? macro expands to the list of all dependents that are out-of- date with
respect to the target file. The "$(?: =-+)" part of the command-line is a macro
substitution to be performed on the $? macro. This substitution instructs NMAKE
expand $? to the list of out-of-date dependents, but then replace all spaces in
the expanded list with the two-character pair "-+".
For example, assume that only MOD1.OBJ, MOD3.OBJ, and MOD4.OBJ are each
out-of-date with respect to MYLIB.LIB. The $? macro expands to the following:
MOD1.OBJ MOD3.OBJ MOD4.OBJ
Therefore, $(?: =-+) actually causes the macro to be expanded with substitution
as follows:
MOD1.OBJ-+MOD3.OBJ-+MOD4.OBJ
With the remainder of the command line included for reference, the NMAKE executes
the following command line:
LIB MYLIB.LIB -+MOD1.OBJ-+MOD3.OBJ-+MOD4.OBJ;
Note that the first time you add a module to the library with this command, LIB
generates a "U4155: module not in library" warning to indicate that LIB is
unable to replace a module because it is not found in the library. You can
ignore the warning because LIB simply adds the module to the library.
This method works correctly as long as the OBJS macro does not contain too many
modules. If the macro expansion causes the command line to exceed the MS-DOS or
OS/2 command-line length limit (128 or 255 characters, respectively), the LIB
call fails. If your library contains enough modules such that this may occur,
then you should use the NMAKE in-line file capability to generate a response
file.
Sample makefile 2 below demonstrates the response file method. The makefile
creates a response file named MYLIB.LRF that contains the lines of the makefile
between the double angle bracket (<<) tokens. The contents of the makefile
reflect a macro substitution that is very similar to the method demonstrated
above. The major difference is as follows: an input line in the response file is
required for each LIB prompt. Therefore, the macro substitution must place
newline characters into the file. The following command does this:
-+$(?: = &^
-+);
This command instructs NMAKE to expand the macro for out-of-date dependents by
replacing each space with a space, and ampersand (&), a newline and a "-+"
character pair. The caret (^) instructs NMAKE to interpret the next character
literally, to place the newline character that follows the caret into the macro.
(Because you type ENTER to place a newline character into the file, the end of
the macro substitution must appear on the following line.)
Therefore, given the same scenario as above, if MOD1.OBJ, MOD3.OBJ, and MOD4.OBJ
are out-of-date with respect to MYLIB.LIB, the $? macro expands to the
following:
-+MOD1.OBJ &
-+MOD3.OBJ &
-+MOD4.OBJ;
With this method, you can maintain any number of object files with one call to
LIB.
Note: NMAKE version 1.1 (provided with Microsoft C versions 6.0 and 6.0a) does
not expand the $? macro correctly unless the target- dependency line uses the
multiple dependency operator, a double colon (::). To work around this problem,
modify the makefile to specify a double colon instead of a single colon for the
dependency that involves the library.
For more information on macro substitution or in-line files, please refer to the
NMAKE documentation or online help provided with your compiler. For more
information on response files, please refer to the LIB or LINK documentation or
online help.
Sample NMAKE Makefile 1
-----------------------
# The OBJS macro lists the object files to keep in the library.
OBJS = MOD1.OBJ MOD2.OBJ MOD3.OBJ MOD4.OBJ
.c.obj:
cl /c $?
.asm.obj:
masm $?;
mylib.lib : $(OBJS)
LIB MYLIB.LIB -+$(?: =-+);
Sample NMAKE Makefile 2
-----------------------
# The OBJS macro lists the object files to keep in the library.
OBJS = MOD1.OBJ MOD2.OBJ MOD3.OBJ MOD4.OBJ
.c.obj:
cl /c $?
.asm.obj:
masm $?;
mylib.lib : $(OBJS)
LIB $*.LIB @<<MYLIB.LRF
-+$(?: = &^
-+);
<<KEEP
# Note: The word "KEEP" after the << token is optional; it prevents
# NMAKE from deleting the in-line file that it creates. This also
# allows you to view MYLIB.LRF (after you finish running NMAKE) if you
# want to verify what NMAKE writes into the response file. By default,
# NMAKE deletes all in-line files before it terminates.
Additional query words: kbinf 1.10 1.20 1.30 1.40 no32bit
======================================================================
Keywords : kb16bitonly
Technology : kbVCsearch kbAudDeveloper kbNMAKESearch kbNMAKE101DOS kbNMAKE111DOS kbNMAKE112DOS kbNMAKE113DOS kbNMAKE120DOS kbNMAKE130DOS kbNMAKE140DOS kbNMAKE101OS2 kbNMAKE111OS2 kbNMAKE112OS2 kbNMAKE113OS2 kbNMAKE121OS2
Version : :1.01,1.11,1.12,1.13,1.2,1.21,1.3,1.4
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