(make.info.gz) Catalogue of Rules

 
 10.2 Catalogue of Implicit Rules
 ================================
 
 Here is a catalogue of predefined implicit rules which are always
 available unless the makefile explicitly overrides or cancels them.
  Canceling Implicit Rules Canceling Rules, for information on
 canceling or overriding an implicit rule.  The `-r' or
 `--no-builtin-rules' option cancels all predefined rules.
 
    This manual only documents the default rules available on POSIX-based
 operating systems.  Other operating systems, such as VMS, Windows,
 OS/2, etc. may have different sets of default rules.  To see the full
 list of default rules and variables available in your version of GNU
 `make', run `make -p' in a directory with no makefile.
 
    Not all of these rules will always be defined, even when the `-r'
 option is not given.  Many of the predefined implicit rules are
 implemented in `make' as suffix rules, so which ones will be defined
 depends on the "suffix list" (the list of prerequisites of the special
 target `.SUFFIXES').  The default suffix list is: `.out', `.a', `.ln',
 `.o', `.c', `.cc', `.C', `.cpp', `.p', `.f', `.F', `.r', `.y', `.l',
 `.s', `.S', `.mod', `.sym', `.def', `.h', `.info', `.dvi', `.tex',
 `.texinfo', `.texi', `.txinfo', `.w', `.ch' `.web', `.sh', `.elc',
 `.el'.  All of the implicit rules described below whose prerequisites
 have one of these suffixes are actually suffix rules.  If you modify
 the suffix list, the only predefined suffix rules in effect will be
 those named by one or two of the suffixes that are on the list you
 specify; rules whose suffixes fail to be on the list are disabled.
  Old-Fashioned Suffix Rules Suffix Rules, for full details on
 suffix rules.
 
 Compiling C programs
      `N.o' is made automatically from `N.c' with a command of the form
      `$(CC) -c $(CPPFLAGS) $(CFLAGS)'.
 
 Compiling C++ programs
      `N.o' is made automatically from `N.cc', `N.cpp', or `N.C' with a
      command of the form `$(CXX) -c $(CPPFLAGS) $(CXXFLAGS)'.  We
      encourage you to use the suffix `.cc' for C++ source files instead
      of `.C'.
 
 Compiling Pascal programs
      `N.o' is made automatically from `N.p' with the command `$(PC) -c
      $(PFLAGS)'.
 
 Compiling Fortran and Ratfor programs
      `N.o' is made automatically from `N.r', `N.F' or `N.f' by running
      the Fortran compiler.  The precise command used is as follows:
 
     `.f'
           `$(FC) -c $(FFLAGS)'.
 
     `.F'
           `$(FC) -c $(FFLAGS) $(CPPFLAGS)'.
 
     `.r'
           `$(FC) -c $(FFLAGS) $(RFLAGS)'.
 
 Preprocessing Fortran and Ratfor programs
      `N.f' is made automatically from `N.r' or `N.F'.  This rule runs
      just the preprocessor to convert a Ratfor or preprocessable
      Fortran program into a strict Fortran program.  The precise
      command used is as follows:
 
     `.F'
           `$(FC) -F $(CPPFLAGS) $(FFLAGS)'.
 
     `.r'
           `$(FC) -F $(FFLAGS) $(RFLAGS)'.
 
 Compiling Modula-2 programs
      `N.sym' is made from `N.def' with a command of the form `$(M2C)
      $(M2FLAGS) $(DEFFLAGS)'.  `N.o' is made from `N.mod'; the form is:
      `$(M2C) $(M2FLAGS) $(MODFLAGS)'.
 
 Assembling and preprocessing assembler programs
      `N.o' is made automatically from `N.s' by running the assembler,
      `as'.  The precise command is `$(AS) $(ASFLAGS)'.
 
      `N.s' is made automatically from `N.S' by running the C
      preprocessor, `cpp'.  The precise command is `$(CPP) $(CPPFLAGS)'.
 
 Linking a single object file
      `N' is made automatically from `N.o' by running the linker
      (usually called `ld') via the C compiler.  The precise command
      used is `$(CC) $(LDFLAGS) N.o $(LOADLIBES) $(LDLIBS)'.
 
      This rule does the right thing for a simple program with only one
      source file.  It will also do the right thing if there are multiple
      object files (presumably coming from various other source files),
      one of which has a name matching that of the executable file.
      Thus,
 
           x: y.o z.o
 
      when `x.c', `y.c' and `z.c' all exist will execute:
 
           cc -c x.c -o x.o
           cc -c y.c -o y.o
           cc -c z.c -o z.o
           cc x.o y.o z.o -o x
           rm -f x.o
           rm -f y.o
           rm -f z.o
 
      In more complicated cases, such as when there is no object file
      whose name derives from the executable file name, you must write
      an explicit command for linking.
 
      Each kind of file automatically made into `.o' object files will
      be automatically linked by using the compiler (`$(CC)', `$(FC)' or
      `$(PC)'; the C compiler `$(CC)' is used to assemble `.s' files)
      without the `-c' option.  This could be done by using the `.o'
      object files as intermediates, but it is faster to do the
      compiling and linking in one step, so that's how it's done.
 
 Yacc for C programs
      `N.c' is made automatically from `N.y' by running Yacc with the
      command `$(YACC) $(YFLAGS)'.
 
 Lex for C programs
      `N.c' is made automatically from `N.l' by running Lex.  The actual
      command is `$(LEX) $(LFLAGS)'.
 
 Lex for Ratfor programs
      `N.r' is made automatically from `N.l' by running Lex.  The actual
      command is `$(LEX) $(LFLAGS)'.
 
      The convention of using the same suffix `.l' for all Lex files
      regardless of whether they produce C code or Ratfor code makes it
      impossible for `make' to determine automatically which of the two
      languages you are using in any particular case.  If `make' is
      called upon to remake an object file from a `.l' file, it must
      guess which compiler to use.  It will guess the C compiler, because
      that is more common.  If you are using Ratfor, make sure `make'
      knows this by mentioning `N.r' in the makefile.  Or, if you are
      using Ratfor exclusively, with no C files, remove `.c' from the
      list of implicit rule suffixes with:
 
           .SUFFIXES:
           .SUFFIXES: .o .r .f .l ...
 
 Making Lint Libraries from C, Yacc, or Lex programs
      `N.ln' is made from `N.c' by running `lint'.  The precise command
      is `$(LINT) $(LINTFLAGS) $(CPPFLAGS) -i'.  The same command is
      used on the C code produced from `N.y' or `N.l'.
 
 TeX and Web
      `N.dvi' is made from `N.tex' with the command `$(TEX)'.  `N.tex'
      is made from `N.web' with `$(WEAVE)', or from `N.w' (and from
      `N.ch' if it exists or can be made) with `$(CWEAVE)'.  `N.p' is
      made from `N.web' with `$(TANGLE)' and `N.c' is made from `N.w'
      (and from `N.ch' if it exists or can be made) with `$(CTANGLE)'.
 
 Texinfo and Info
      `N.dvi' is made from `N.texinfo', `N.texi', or `N.txinfo', with
      the command `$(TEXI2DVI) $(TEXI2DVI_FLAGS)'.  `N.info' is made from
      `N.texinfo', `N.texi', or `N.txinfo', with the command
      `$(MAKEINFO) $(MAKEINFO_FLAGS)'.
 
 RCS
      Any file `N' is extracted if necessary from an RCS file named
      either `N,v' or `RCS/N,v'.  The precise command used is
      `$(CO) $(COFLAGS)'.  `N' will not be extracted from RCS if it
      already exists, even if the RCS file is newer.  The rules for RCS
      are terminal ( Match-Anything Pattern Rules Match-Anything
      Rules.), so RCS files cannot be generated from another source;
      they must actually exist.
 
 SCCS
      Any file `N' is extracted if necessary from an SCCS file named
      either `s.N' or `SCCS/s.N'.  The precise command used is
      `$(GET) $(GFLAGS)'.  The rules for SCCS are terminal (
      Match-Anything Pattern Rules Match-Anything Rules.), so SCCS
      files cannot be generated from another source; they must actually
      exist.
 
      For the benefit of SCCS, a file `N' is copied from `N.sh' and made
      executable (by everyone).  This is for shell scripts that are
      checked into SCCS.  Since RCS preserves the execution permission
      of a file, you do not need to use this feature with RCS.
 
      We recommend that you avoid using of SCCS.  RCS is widely held to
      be superior, and is also free.  By choosing free software in place
      of comparable (or inferior) proprietary software, you support the
      free software movement.
 
    Usually, you want to change only the variables listed in the table
 above, which are documented in the following section.
 
    However, the commands in built-in implicit rules actually use
 variables such as `COMPILE.c', `LINK.p', and `PREPROCESS.S', whose
 values contain the commands listed above.
 
    `make' follows the convention that the rule to compile a `.X' source
 file uses the variable `COMPILE.X'.  Similarly, the rule to produce an
 executable from a `.X' file uses `LINK.X'; and the rule to preprocess a
 `.X' file uses `PREPROCESS.X'.
 
    Every rule that produces an object file uses the variable
 `OUTPUT_OPTION'.  `make' defines this variable either to contain `-o
 $@', or to be empty, depending on a compile-time option.  You need the
 `-o' option to ensure that the output goes into the right file when the
 source file is in a different directory, as when using `VPATH' (
 Directory Search).  However, compilers on some systems do not accept
 a `-o' switch for object files.  If you use such a system, and use
 `VPATH', some compilations will put their output in the wrong place.  A
 possible workaround for this problem is to give `OUTPUT_OPTION' the
 value `; mv $*.o $@'.
Info Catalog
(make.info.gz) Using Implicit
(make.info.gz) Implicit Rules
(make.info.gz) Implicit Variables
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