re PR c/30551 (-pedantic does not include -Wmain, but -pedantic-errors does make -Wmain cause error messages)

2008-08-13  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR 30551
	* doc/invoke.texi (Wmain): Update.
	* c-decl.c (start_decl): warn_main is only 0 or 1.
	(start_function): Likewise. Fix formatting.
	(finish_function): Delete redundant warning.
	* c.opt (Wmain): Add Var(warn_main) and Init(-1).
	* c-opts (c_common_handle_option): -Wall only has effect if
	warn_main is uninitialized. OPT_Wmain is automatically
	handled. -pedantic also enables Wmain.
	(c_common_post_options): Handle all logic for Wmain here.
	* c-common.c (warn_main): Delete.
	(check_main_parameter_types): Make pedwarns conditional on
	OPT_Wmain.
	* c-common.h (warn_main): Delete.
cp/	
	* decl.c (grokfndecl): Call check_main_parameters_type only if
	-Wmain.
testsuite/
	* gcc.dg/pr30551.c: New.
	* gcc.dg/pr30551-2.c: New.
	* gcc.dg/pr30551-3.c: New.
	* gcc.dg/pr30551-4.c: New.
	* gcc.dg/pr30551-5.c: New.
	* gcc.dg/pr30551-6.c: New.
	* gcc.dg/tree-ssa/reassoc-3.c: Don't compile with -pedantic-errors.
	* g++.dg/warn/pr30551.C: New.
	* g++.dg/warn/pr30551-2.C: New.

From-SVN: r139063

1 files changed, 17 insertions, 13 deletions

diff --git a/gcc/c-opts.c b/gcc/c-opts.c
index 83e2ed1..300bf14 100644
--- a/gcc/c-opts.c
+++ b/gcc/c-opts.c
@@ -404,9 +404,12 @@ c_common_handle_option (size_t scode, const char *arg, int value)
 	warn_uninitialized = (value ? 2 : 0);
 
       if (!c_dialect_cxx ())
-	/* We set this to 2 here, but 1 in -Wmain, so -ffreestanding
-	   can turn it off only if it's not explicit.  */
-	warn_main = value * 2;
+	{
+	  /* We set this to 2 here, but 1 in -Wmain, so -ffreestanding
+	     can turn it off only if it's not explicit.  */
+	  if (warn_main == -1)
+	    warn_main = (value ? 2 : 0);
+	}
       else
 	{
 	  /* C++-specific warnings.  */
@@ -467,13 +470,6 @@ c_common_handle_option (size_t scode, const char *arg, int value)
       cpp_opts->warn_invalid_pch = value;
       break;
 
-    case OPT_Wmain:
-      if (value)
-	warn_main = 1;
-      else
-	warn_main = -1;
-      break;
-
     case OPT_Wmissing_include_dirs:
       cpp_opts->warn_missing_include_dirs = value;
       break;
@@ -615,9 +611,6 @@ c_common_handle_option (size_t scode, const char *arg, int value)
     case OPT_fhosted:
       flag_hosted = value;
       flag_no_builtin = !value;
-      /* warn_main will be 2 if set by -Wall, 1 if set by -Wmain */
-      if (!value && warn_main == 2)
-	warn_main = 0;
       break;
 
     case OPT_fshort_double:
@@ -907,6 +900,8 @@ c_common_handle_option (size_t scode, const char *arg, int value)
 	warn_pointer_sign = 1;
       if (warn_overlength_strings == -1)
 	warn_overlength_strings = 1;
+      if (warn_main == -1)
+	warn_main = 2;
       break;
 
     case OPT_print_objc_runtime_info:
@@ -1071,6 +1066,15 @@ c_common_post_options (const char **pfilename)
   if (warn_overlength_strings == -1 || c_dialect_cxx ())
     warn_overlength_strings = 0;
 
+  /* Wmain is enabled by default in C++ but not in C.  */
+  /* Wmain is disabled by default for -ffreestanding (!flag_hosted),
+     even if -Wall was given (warn_main will be 2 if set by -Wall, 1
+     if set by -Wmain).  */
+  if (warn_main == -1)
+    warn_main = (c_dialect_cxx () && flag_hosted) ? 1 : 0;
+  else if (warn_main == 2)
+    warn_main = flag_hosted ? 1 : 0;
+
   /* In C, -Wconversion enables -Wsign-conversion (unless disabled
      through -Wno-sign-conversion). While in C++,
      -Wsign-conversion needs to be requested explicitly.  */