re PR preprocessor/7358 (Changes to Sun's make Dependencies)

	PR preprocessor/7358
	* c-opts.c (check_deps_environment_vars): Ignore main file
	for SUNPRO_DEPENDENCIES.
	* cppfiles.c (stack_include_file): Ignore main file if
	appropriate.
	* cpplib.h (struct cpp_options): New member in deps.
	* doc/cppenv.texi: Update.

From-SVN: r56333

gcc/ChangeLog

+2002-08-15  Neil Booth  <neil@daikokuya.co.uk>
+
+	PR preprocessor/7358
+	* c-opts.c (check_deps_environment_vars): Ignore main file
+	for SUNPRO_DEPENDENCIES.
+	* cppfiles.c (stack_include_file): Ignore main file if
+	appropriate.
+	* cpplib.h (struct cpp_options): New member in deps.
+	* doc/cppenv.texi: Update.
+
 2002-08-14  Neil Booth  <neil@daikokuya.co.uk>
 
 	PR preprocessor/7526

gcc/c-opts.c

@@ -1467,7 +1467,8 @@ c_common_finish ()
    DEPS_TARGET", where OUTPUT_FILE is the file to write deps info to
    and DEPS_TARGET is the target to mention in the deps.  They also
    result in dependency information being appended to the output file
-   rather than overwriting it.  */
+   rather than overwriting it, and like Sun's compiler
+   SUNPRO_DEPENDENCIES suppresses the dependency on the main file.  */
 static void
 check_deps_environment_vars ()
 {
@@ -1480,7 +1481,10 @@ check_deps_environment_vars ()
     {
       GET_ENVIRONMENT (spec, "SUNPRO_DEPENDENCIES");
       if (spec)
+	{
 	  cpp_opts->deps.style = DEPS_SYSTEM;
+	  cpp_opts->deps.ignore_main_file = true;
+	}
     }
 
   if (spec)

gcc/cppfiles.c

@@ -318,9 +318,12 @@ stack_include_file (pfile, inc)
   sysp = MAX ((pfile->map ? pfile->map->sysp : 0),
 	      (inc->foundhere ? inc->foundhere->sysp : 0));
 
-  /* For -M, add the file to the dependencies on its first inclusion.  */
+  /* Add the file to the dependencies on its first inclusion.  */
   if (CPP_OPTION (pfile, deps.style) > !!sysp && !inc->include_count)
+    {
+      if (pfile->buffer || CPP_OPTION (pfile, deps.ignore_main_file) == 0)
 	deps_add_dep (pfile->deps, inc->name);
+    }
 
   /* Not in cache?  */
   if (! inc->buffer)

gcc/cpplib.h

@@ -387,6 +387,9 @@ struct cpp_options
     /* Generate phony targets for each dependency apart from the first
        one.  */
     bool phony_targets;
+
+    /* If true, no dependency is generated on the main file.  */
+    bool ignore_main_file;
   } deps;
 
   /* Target-specific features set by the front end or client.  */

gcc/doc/cppenv.texi

@@ -72,7 +72,8 @@ with an optional @option{-MT} switch too.
 @cindex dependencies for make as output
 This variable is the same as @env{DEPENDENCIES_OUTPUT} (see above),
 except that system header files are not ignored, so it implies
-@option{-M} rather than @option{-MM}.
+@option{-M} rather than @option{-MM}.  However, the dependence on the
+main input file is omitted.
 @ifset cppmanual
 @xref{Invocation}.
 @end ifset