* Added -R / --no-builtin-variables flag.

ChangeLog

@@ -1,3 +1,14 @@
+1999-07-08  Paul D. Smith  <psmith@gnu.org>
+
+	* main.c (switches): Define a new switch -R (or
+	--no-builtin-variables).  This option disables the defining of all
+	the GNU make builtin variables.
+	(main): If -R was given, force -r as well.
+	* default.c (define_default_variables): Test the new flag.
+	* make.h: Declare global flag.
+	* make.texinfo (Options Summary): Document the new option.
+	(Implicit Variables): Ditto.
+
 1999-07-06  Paul D. Smith  <psmith@gnu.org>
 
 	* make.texinfo (Options Summary): Correct examples in

NEWS

@@ -24,6 +24,11 @@ Version 3.78
 * Make allows CRLF sequences as well as traditional LF, for
   compatibility with makefiles created on other operating systems.
 
+* Make accepts a new option: -R, or --no-builtin-variables.  This option
+  disables the definition of the rule-specific builtin variables (CC,
+  LD, AR, etc.).  Specifying this option forces -r (--no-builtin-rules)
+  as well.
+
 * A "job server" feature, proposed by Howard Chu <hyc@highlandsun.com>.
 
   On systems that support POSIX pipe(2) semantics, GNU make can now pass

default.c

@@ -509,6 +509,9 @@ define_default_variables ()
 {
   register char **s;
 
+  if (no_builtin_variables_flag)
+    return;
+
   for (s = default_variables; *s != 0; s += 2)
     (void) define_variable (s[0], strlen (s[0]), s[1], o_default, 1);
 }

main.c

@@ -61,9 +61,9 @@ extern void print_vpath_data_base PARAMS ((void));
 extern int chdir ();
 #endif
 #ifndef	STDC_HEADERS
-#ifndef	sun			/* Sun has an incorrect decl in a header.  */
+# ifndef sun			/* Sun has an incorrect decl in a header.  */
 extern void exit PARAMS ((int)) __attribute__ ((noreturn));
-#endif
+# endif
 extern double atof ();
 #endif
 extern char *mktemp ();
@@ -163,9 +163,10 @@ int print_data_base_flag = 0;
 
 int question_flag = 0;
 
-/* Nonzero means do not use any of the builtin rules (-r).  */
+/* Nonzero means do not use any of the builtin rules (-r) / variables (-R).  */
 
 int no_builtin_rules_flag = 0;
+int no_builtin_variables_flag = 0;
 
 /* Nonzero means keep going even if remaking some file fails (-k).  */
 
@@ -317,6 +318,9 @@ static const struct command_switch switches[] =
     { 'r', flag, (char *) &no_builtin_rules_flag, 1, 1, 0, 0, 0,
 	"no-builtin-rules", 0,
 	"Disable the built-in implicit rules" },
+    { 'R', flag, (char *) &no_builtin_variables_flag, 1, 1, 0, 0, 0,
+	"no-builtin-variables", 0,
+	"Disable the built-in variable settings" },
     { 's', flag, (char *) &silent_flag, 1, 1, 0, 0, 0,
 	"silent", 0,
 	"Don't echo commands" },
@@ -1065,6 +1069,10 @@ int main (int argc, char ** argv)
   if (inhibit_print_directory_flag)
     print_directory_flag = 0;
 
+  /* If -R was given, set -r too (doesn't make sense otherwise!)  */
+  if (no_builtin_variables_flag)
+    no_builtin_rules_flag = 1;
+
   /* Construct the list of include directories to search.  */
 
   construct_include_path (include_directories == 0 ? (char **) 0

make.h

@@ -449,9 +449,9 @@ extern char **environ;
 
 extern int just_print_flag, silent_flag, ignore_errors_flag, keep_going_flag;
 extern int debug_flag, print_data_base_flag, question_flag, touch_flag;
-extern int env_overrides, no_builtin_rules_flag, print_version_flag;
-extern int print_directory_flag, warn_undefined_variables_flag;
-extern int posix_pedantic;
+extern int env_overrides, no_builtin_rules_flag, no_builtin_variables_flag;
+extern int print_version_flag, print_directory_flag;
+extern int warn_undefined_variables_flag, posix_pedantic;
 extern int clock_skew_detected;
 
 /* can we run commands via 'sh -c xxx' or must we use batch files? */

make.texinfo

@@ -6668,7 +6668,17 @@ Rules}).  But you can still define your own suffixes with a rule for
 @code{.SUFFIXES}, and then define your own suffix rules.  Note that only
 @emph{rules} are affected by the @code{-r} option; default variables
 remain in effect (@pxref{Implicit Variables, ,Variables Used by Implicit
-Rules}).
+Rules}); see the @samp{-R} option below.
+
+@item -R
+@cindex @code{-R}
+@itemx --no-builtin-variables
+@cindex @code{--no-builtin-variables}
+Eliminate use of the built-in rule-specific variables (@pxref{Implicit
+Variables, ,Variables Used by Implicit Rules}).  You can still define
+your own, of course.  The @samp{-R} option also automatically enables
+the @samp{-r} option (see above), since it doesn't make sense to have
+implicit rules without any definitions for the variables that they use.
 
 @item -s
 @cindex @code{-s}
@@ -7201,7 +7211,9 @@ the value @w{@samp{; mv $*.o $@@}}.
 The commands in built-in implicit rules make liberal use of certain
 predefined variables.  You can alter these variables in the makefile,
 with arguments to @code{make}, or in the environment to alter how the
-implicit rules work without redefining the rules themselves.
+implicit rules work without redefining the rules themselves.  You can
+cancel all variables used by implicit rules with the @samp{-R} or
+@samp{--no-builtin-variables} option.
 
 For example, the command used to compile a C source file actually says
 @samp{$(CC) -c $(CFLAGS) $(CPPFLAGS)}.  The default values of the variables