Don't make -gsplit-dwarf imply -g

-gsplit-dwarf introduces order dependency: it overrides previous -g0 and -g1.

Don't imply -g so that it can be plugged into a build without worrying
that unnecessary debugging information may be generated.

2020-05-13  Fangrui Song  <maskray@google.com>

	PR debug/95096
	* opts.c (common_handle_option): Don't make -gsplit-dwarf imply -g.
	* doc/invoke.texi (-gsplit-dwarf): Update documentation.

2 files changed, 5 insertions, 10 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7c3cc14..eaaf6d0 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -9166,11 +9166,11 @@ except when selective scheduling is enabled.
 
 @item -gsplit-dwarf
 @opindex gsplit-dwarf
-Separate as much DWARF debugging information as possible into a
-separate output file with the extension @file{.dwo}.  This option allows
-the build system to avoid linking files with debug information.  To
-be useful, this option requires a debugger capable of reading @file{.dwo}
-files.
+If DWARF debugging information is enabled, separate as much debugging
+information as possible into a separate output file with the extension
+@file{.dwo}.  This option allows the build system to avoid linking files with
+debug information.  To be useful, this option requires a debugger capable of
+reading @file{.dwo} files.
 
 @item -gdescribe-dies
 @opindex gdescribe-dies
diff --git a/gcc/opts.c b/gcc/opts.c
index 6628f7e..68321cc 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -2704,11 +2704,6 @@ common_handle_option (struct gcc_options *opts,
       set_debug_level (DWARF2_DEBUG, false, "", opts, opts_set, loc);
       break;
 
-    case OPT_gsplit_dwarf:
-      set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, "", opts, opts_set,
-		       loc);
-      break;
-
     case OPT_ggdb:
       set_debug_level (NO_DEBUG, 2, arg, opts, opts_set, loc);
       break;