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─────Programmer's WorkBench─────────────────────────────────────────────────
 
     The usual structure of the build process is:
 
     FILE.C  ──compile──►  FILE.OBJ  ──link──►  PROGRAM.EXE
 
     A description block for PROGRAM.EXE is given in the makefile, with
     FILE.OBJ listed as a dependent. NMAKE applies the .c.obj inference
     rule to compile FILE.SRC into FILE.OBJ.
 
     However, when using a preprocesssor that generates a source file,
     the build process is:
 
     FILE.PRE ──tool──►  FILE.C  ──compile──►  FILE.OBJ  ...
 
     FILE.OBJ is indirectly dependent on FILE.PRE. Intuitively, it seems
     that all that is necessary is to define a .pre.c inference rule and
     add .pre to the .SUFFIXES list. However, this does not work.
 
     If FILE.PRE is modified and FILE.C exists from a previous build,
     NMAKE does not close the indirect dependency from FILE.PRE to
     FILE.OBJ. Because there is a .c.obj inference rule, NMAKE first
     checks FILE.OBJ against FILE.C, finds that FILE.OBJ is up-to-date
     with respect to FILE.C, and performs no action.
 
     You can handle this by short-circuiting the indirect dependency as
     follows:
 
       ■  Create a .pre.obj inference rule.
 
          This defines an inference rule that describes how to build
          the object file directly from the preprocessor source file.
          The build rule to define this is:
 
               Build: inference .pre.obj tool_pre_c cc_c_obj
 
          Note that the standard C compiler command (cc_c_obj) is reused
          to perform that part of the build.
 
       ■  List .pre before .src in the .SUFFIXES list.
 
          This ensures that NMAKE checks the modification date of
          FILE.OBJ against FILE.PRE before checking FILE.C. The build
          rule to define this is:
 
               Build: suffixes .pre
 
          PWB automatically appends .c to the .SUFFIXES list when it
          creates the makefile.
 
     These rules should be added to a previously saved custom project
     template that is appropriate for the language and type of project
     that you want to build.
 
     See
 
     ◄Build:suffixes►
     ◄How PWB Creates a Project Makefile►
     ◄NMAKE .SUFFIXES Directive►
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