[gcc(refs/users/guojiufu/heads/personal-branch)] Don't make -gsplit-dwarf imply -g

[Jiu Fu Guo]

https://gcc.gnu.org/g:c8d3f2b6d1d81535ac3b71fd8dd1def12f8d03b3

commit c8d3f2b6d1d81535ac3b71fd8dd1def12f8d03b3
Author: Fangrui Song <maskray@google.com>
Date:   Wed May 13 08:27:29 2020 -0700

    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.

Diff:
---
 gcc/doc/invoke.texi | 10 +++++-----
 gcc/opts.c          |  5 -----
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7c3cc141c01..eaaf6d06b65 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 6628f7e8f13..68321cce81e 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;