common.opt (gdwarf-): Initialize dwarf_version to -1 instead of 2.

        * common.opt (gdwarf-): Initialize dwarf_version to -1 instead of 2.
        * toplev.c (process_options): Default to dwarf_version 2.
        * config/vxworks.c (vxworks_override_options): Default to strict-dwarf
        and dwarf_version 2.

From-SVN: r186783

gcc/ChangeLog

+2012-04-24  Olivier Hainque  <hainque@adacore.com>
+
+	* common.opt (gdwarf-): Initialize dwarf_version to -1 instead of 2.
+	* toplev.c (process_options): Default to dwarf_version 2.
+	* config/vxworks.c (vxworks_override_options): Default to strict-dwarf
+	and dwarf_version 2.
+
 2012-04-24  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	* tree-pretty-print.h (default_tree_printer): Do not declare.

gcc/common.opt

@@ -2212,7 +2212,7 @@ Common JoinedOrMissing Negative(gdwarf-)
 Generate debug information in COFF format
 
 gdwarf-
-Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
+Common Joined UInteger Var(dwarf_version) Init(-1) Negative(gstabs)
 Generate debug information in DWARF v2 (or later) format
 
 ggdb

gcc/config/vxworks.c

@@ -144,4 +144,12 @@ vxworks_override_options (void)
   /* PIC is only supported for RTPs.  */
   if (flag_pic && !TARGET_VXWORKS_RTP)
     error ("PIC is only supported for RTPs");
+
+  /* Default to strict dwarf-2 to prevent potential difficulties observed with
+     non-gdb debuggers on extensions > 2.  */
+  if (dwarf_strict < 0)
+    dwarf_strict = 1;
+
+  if (dwarf_version < 0)
+    dwarf_version = 2;
 }

gcc/toplev.c

@@ -1380,6 +1380,10 @@ process_options (void)
   if (dwarf_strict < 0)
     dwarf_strict = 0;
 
+  /* And select a default dwarf level.  */
+  if (dwarf_version < 0)
+    dwarf_version = 2;
+
   /* A lot of code assumes write_symbols == NO_DEBUG if the debugging
      level is 0.  */
   if (debug_info_level == DINFO_LEVEL_NONE)