* cppexp.c (parse_defined): Mark macro used.

	* cpphash.h (struct cpp_macro): New member "used".
	(_cpp_mark_macro_used, _cpp_warn_if_unused_macro): New.
	(struct cpp_reader): New member.
	* cppinit.c (cpp_finish_options): Set first_unused_line.
	(cpp_finish): Warn of unused macros if requested.
	(OPT_TABLE): New switches.
	(cpp_handle_option): Handle them.
	* cpplib.c (do_undef): Warn if macro unused.
	(do_ifdef, do_ifndef): Mark macro used.
	* cpplib.h (struct cpp_options): New member.
	* cppmacro.c (_cpp_warn_if_unused_macro): New.
	(enter_macro_context): Mark macro used.
	(_cpp_create_definition): Mark macro unused; warn if unused
	when redefined.
	* cpptrad.c (scan_out_logcial_line, push_replacement_text):
	Mark macros used.
	* doc/cppopts.texi: Update.
testsuite:
	* gcc.dg/cpp/trad/Wunused.c, gcc.dg/cpp/trad/Wunused.h,
	gcc.dg/cpp/Wunused.c, gcc.dg/cpp/Wunused.h: New tests.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@55692 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/cppinit.c b/gcc/cppinit.c
index a6be4aa6736..6a4dd0a53f8 100644
--- a/gcc/cppinit.c
+++ b/gcc/cppinit.c
@@ -1009,6 +1009,8 @@ cpp_finish_options (pfile)
       _cpp_maybe_push_include_file (pfile);
     }
 
+  pfile->first_unused_line = pfile->line;
+
   free_chain (CPP_OPTION (pfile, pending)->imacros_head);
   free_chain (CPP_OPTION (pfile, pending)->directive_head);
 }
@@ -1081,6 +1083,10 @@ void
 cpp_finish (pfile)
      cpp_reader *pfile;
 {
+  /* Warn about unused macros before popping the final buffer.  */
+  if (CPP_OPTION (pfile, warn_unused_macros))
+    cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
+
   /* cpplex.c leaves the final buffer on the stack.  This it so that
      it returns an unending stream of CPP_EOFs to the client.  If we
      popped the buffer, we'd dereference a NULL buffer pointer and
@@ -1165,10 +1171,12 @@ new_pending_directive (pend, text, handler)
   DEF_OPT("Wno-traditional",          0,      OPT_Wno_traditional)            \
   DEF_OPT("Wno-trigraphs",            0,      OPT_Wno_trigraphs)              \
   DEF_OPT("Wno-undef",                0,      OPT_Wno_undef)                  \
+  DEF_OPT("Wno-unused-macros",        0,      OPT_Wno_unused_macros)          \
   DEF_OPT("Wsystem-headers",          0,      OPT_Wsystem_headers)            \
   DEF_OPT("Wtraditional",             0,      OPT_Wtraditional)               \
   DEF_OPT("Wtrigraphs",               0,      OPT_Wtrigraphs)                 \
   DEF_OPT("Wundef",                   0,      OPT_Wundef)                     \
+  DEF_OPT("Wunused-macros",           0,      OPT_Wunused_macros)             \
   DEF_OPT("d",                        no_arg, OPT_d)                          \
   DEF_OPT("fno-operator-names",       0,      OPT_fno_operator_names)         \
   DEF_OPT("fno-preprocessed",         0,      OPT_fno_preprocessed)           \
@@ -1692,6 +1700,13 @@ cpp_handle_option (pfile, argc, argv)
 	  CPP_OPTION (pfile, warn_comments) = 0;
 	  break;
 
+	case OPT_Wunused_macros:
+	  CPP_OPTION (pfile, warn_unused_macros) = 1;
+	  break;
+	case OPT_Wno_unused_macros:
+	  CPP_OPTION (pfile, warn_unused_macros) = 0;
+	  break;
+
 	case OPT_Wundef:
 	  CPP_OPTION (pfile, warn_undef) = 1;
 	  break;