Sample Makefile for PCH

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The following makefile uses macros and an !IF, !ELSE, !ENDIF flow-of-control command structure to simplify its adaptation to your project.

# Makefile : Illustrates the effective use of precompiled
#            headers in a project
# Usage:     NMAKE option
# option:    DEBUG=[0|1]
#            (DEBUG not defined is equivalent to DEBUG=0)
#
OBJS = myapp.obj applib.obj
# List all stable header files in the STABLEHDRS macro.
STABLEHDRS = stable.h another.h
# List the final header file to be precompiled here:
BOUNDRY = stable.h
# List header files under development here:
UNSTABLEHDRS = unstable.h
# List all compiler options common to both debug and final
# versions of your code here:
CLFLAGS = /c /W3
# List all linker options common to both debug and final
# versions of your code here:
LINKFLAGS = /NOD /ONERROR:NOEXE
!IF "$(DEBUG)" == "1"
CLFLAGS   = /D_DEBUG $(CLFLAGS) /Od /Zi /f
LINKFLAGS = $(LINKFLAGS) /COD
LIBS      = slibce
!ELSE
CLFLAGS   = $(CLFLAGS) /Oselg /Gs
LINKFLAGS = $(LINKFLAGS)
LIBS      = slibce
!ENDIF
myapp.exe: $(OBJS)
    link $(LINKFLAGS) @<<
$(OBJS), myapp, NUL, $(LIBS), NUL;
<<
# Compile myapp
myapp.obj  : myapp.cpp $(UNSTABLEHDRS)  stable.pch
    $(CPP) $(CLFLAGS) /Yu$(BOUNDRY)    myapp.cpp
# Compile applib
applib.obj : applib.cpp $(UNSTABLEHDRS) stable.pch
    $(CPP) $(CLFLAGS) /Yu$(BOUNDRY)    applib.cpp
# Compile headers
stable.pch : $(STABLEHDRS)
    $(CPP) $(CLFLAGS) /Yc$(BOUNDRY)    applib.cpp myapp.cpp

Besides the STABLEHDRS, BOUNDRY, and UNSTABLEHDRS macros shown in Figure 1, this makefile provides a CLFLAGS macro and a LINKFLAGS macro. You must use these macros to list compiler and linker options that apply whether you build a debug or final version of the application’s executable file. There is also a LIBS macro where you list the libraries that your project requires.

The makefile also uses !IF, !ELSE, !ENDIF to detect whether you define a DEBUG symbol on the NMAKE command line:

NMAKE DEBUG=[1|0]

This feature makes it possible for you to use the same makefile during development and for the final versions of your program—use DEBUG=0 for the final versions. The following command lines are equivalent:

NMAKE 
NMAKE DEBUG=0

For more information on makefiles, see NMAKE Reference. Also see the Compiler Reference and the Linker Reference.