Add a -w option to the linker to suppress warning and error messages.

PR 29654
	* ld.h (struct ld_config_type): Add no_warnings field.
	* ldlex.h (enum option_values): Add OPTION_NO_WARNINGS.
	* lexsup.c (ld_options): Add --no-warnings.
	(parse_args): Add support for -w and --no-warnings.
	* ldmisc.c (vfinfo): Return early if the message is a warning and
	-w has been enabled.
	* ld.texi (options): Document new command line option.
	* NEWS: Mention the new feature.

ld/ChangeLog

@@ -1,3 +1,15 @@
+2022-10-21  Nick Clifton  <nickc@redhat.com>
+
+	PR 29654
+	* ld.h (struct ld_config_type): Add no_warnings field.
+	* ldlex.h (enum option_values): Add OPTION_NO_WARNINGS.
+	* lexsup.c (ld_options): Add --no-warnings.
+	(parse_args): Add support for -w and --no-warnings.
+	* ldmisc.c (vfinfo): Return early if the message is a warning and
+	-w has been enabled.
+	* ld.texi (options): Document new command line option.
+	* NEWS: Mention the new feature.
+
 2022-08-30  Nick Clifton  <nickc@redhat.com>
 
 	PR 29529

ld/NEWS

@@ -1,7 +1,12 @@
 -*- text -*-
 
+* The linker has a new command line option to suppress the generation of any
+  warning or error messages.  This can be useful when there is a need to create
+  a known non-working binary.  The option is -w or --no-warnings.
+
 * ld now supports zstd compressed debug sections.  The new option
   --compress-debug-sections=zstd compresses debug sections with zstd.
+
 * Add --enable-default-compressed-debug-sections-algorithm={zlib,zstd}
   that selects the default compression algorithm
   for --enable-compressed-debug-sections.

ld/ld.h

@@ -252,9 +252,12 @@ typedef struct
      changes due to the alignment of an input section.  */
   bool warn_section_align;
 
-  /* If TRUE, warning messages are fatal */
+  /* If TRUE, warning messages are fatal.  */
   bool fatal_warnings;
 
+  /* If TRUE, warning and error messages are ignored.  */
+  bool no_warnings;
+
   sort_order sort_common;
 
   bool text_read_only;

ld/ld.texi

@@ -1876,6 +1876,15 @@ in filename invoked by -R or --just-symbols
 Treat all warnings as errors.  The default behaviour can be restored
 with the option @option{--no-fatal-warnings}.
 
+@kindex -w
+@kindex --no-warnings
+@item -w
+@itemx --no-warnings
+Do not display any warning or error messages.  This overrides
+@option{--fatal-warnings} if it has been enabled.  This option can be
+used when it is known that the output binary will not work, but there
+is still a need to create it.
+
 @kindex --force-exe-suffix
 @item  --force-exe-suffix
 Make sure that an output file has a .exe suffix.

ld/ldlex.h

@@ -88,6 +88,7 @@ enum option_values
   OPTION_WARN_CONSTRUCTORS,
   OPTION_WARN_FATAL,
   OPTION_NO_WARN_FATAL,
+  OPTION_NO_WARNINGS,
   OPTION_WARN_MULTIPLE_GP,
   OPTION_WARN_ONCE,
   OPTION_WARN_SECTION_ALIGN,

ld/ldmisc.c

@@ -95,6 +95,9 @@ vfinfo (FILE *fp, const char *fmt, va_list ap, bool is_warning)
       } type;
   } args[9];
 
+  if (is_warning && config.no_warnings)
+    return;
+  
   for (arg_no = 0; arg_no < sizeof (args) / sizeof (args[0]); arg_no++)
     args[arg_no].type = Bad;
 

ld/lexsup.c

@@ -381,6 +381,9 @@ static const struct ld_option ld_options[] =
   { {"no-undefined", no_argument, NULL, OPTION_NO_UNDEFINED},
     '\0', NULL, N_("Do not allow unresolved references in object files"),
     TWO_DASHES },
+  { {"no-warnings", no_argument, NULL, OPTION_NO_WARNINGS},
+    'w', NULL, N_("Do not display any warning or error messages"),
+    TWO_DASHES },
   { {"allow-shlib-undefined", no_argument, NULL, OPTION_ALLOW_SHLIB_UNDEFINED},
     '\0', NULL, N_("Allow unresolved references in shared libraries"),
     TWO_DASHES },
@@ -1554,6 +1557,11 @@ parse_args (unsigned argc, char **argv)
 	case OPTION_NO_WARN_FATAL:
 	  config.fatal_warnings = false;
 	  break;
+	case OPTION_NO_WARNINGS:
+	case 'w':
+	  config.no_warnings = true;
+	  config.fatal_warnings = false;
+	  break;
 	case OPTION_WARN_MULTIPLE_GP:
 	  config.warn_multiple_gp = true;
 	  break;