gold: Add -Bno-symbolic

gold/
    PR 27834
    * options.h (General_options): Make -Bsymbolic and
    -Bsymbolic-functions special and adjust the help messages. Add
    enum Bsymbolic_kind and -Bno-symbolic.
    * options.cc (General_options): Define parse_Bno_symbolic,
    parse_Bsymbolic_functions, and parse_Bsymbolic.

gold/ChangeLog

@@ -1,3 +1,12 @@
+2021-05-04  Fangrui Song  <maskray@google.com>
+
+	PR 27834
+	* options.h (General_options): Make -Bsymbolic and
+	-Bsymbolic-functions special and adjust the help messages. Add
+	enum Bsymbolic_kind and -Bno-symbolic.
+	* options.cc (General_options): Define parse_Bno_symbolic,
+	parse_Bsymbolic_functions, and parse_Bsymbolic.
+
 2021-03-30  Alan Modra  <amodra@gmail.com>
 
 	PR gold/27625

gold/options.cc

@@ -340,6 +340,27 @@ General_options::parse_V(const char*, const char*, Command_line*)
     printf("   %s\n", *p);
 }
 
+void
+General_options::parse_Bno_symbolic(const char*, const char*,
+				    Command_line*)
+{
+  this->bsymbolic_ = BSYMBOLIC_NONE;
+}
+
+void
+General_options::parse_Bsymbolic_functions(const char*, const char*,
+					   Command_line*)
+{
+  this->bsymbolic_ = BSYMBOLIC_FUNCTIONS;
+}
+
+void
+General_options::parse_Bsymbolic(const char*, const char*,
+				 Command_line*)
+{
+  this->bsymbolic_ = BSYMBOLIC_ALL;
+}
+
 void
 General_options::parse_defsym(const char*, const char* arg,
 			      Command_line* cmdline)

gold/options.h

@@ -747,11 +747,20 @@ class General_options
   DEFINE_bool(Bshareable, options::ONE_DASH, '\0', false,
 	      N_("Generate shared library (alias for -G/-shared)"), NULL);
 
-  DEFINE_bool(Bsymbolic, options::ONE_DASH, '\0', false,
+  DEFINE_special (Bno_symbolic, options::ONE_DASH, '\0',
-	      N_("Bind defined symbols locally"), NULL);
+		  N_ ("Don't bind default visibility defined symbols locally "
+		      "for -shared (default)"),
+		  NULL);
 
-  DEFINE_bool(Bsymbolic_functions, options::ONE_DASH, '\0', false,
+  DEFINE_special (Bsymbolic_functions, options::ONE_DASH, '\0',
-	      N_("Bind defined function symbols locally"), NULL);
+		  N_ ("Bind default visibility defined function symbols "
+		      "locally for -shared"),
+		  NULL);
+
+  DEFINE_special (
+      Bsymbolic, options::ONE_DASH, '\0',
+      N_ ("Bind default visibility defined symbols locally for -shared"),
+      NULL);
 
   // c
 
@@ -1740,6 +1749,21 @@ class General_options
   endianness() const
   { return this->endianness_; }
 
+  enum Bsymbolic_kind
+  {
+    BSYMBOLIC_NONE,
+    BSYMBOLIC_FUNCTIONS,
+    BSYMBOLIC_ALL,
+  };
+
+  bool
+  Bsymbolic() const
+  { return this->bsymbolic_ == BSYMBOLIC_ALL; }
+
+  bool
+  Bsymbolic_functions() const
+  { return this->bsymbolic_ == BSYMBOLIC_FUNCTIONS; }
+
   bool
   discard_all() const
   { return this->discard_locals_ == DISCARD_ALL; }
@@ -1873,6 +1897,8 @@ class General_options
   void
   copy_from_posdep_options(const Position_dependent_options&);
 
+  // Whether we bind default visibility defined symbols locally for -shared.
+  Bsymbolic_kind bsymbolic_;
   // Whether we printed version information.
   bool printed_version_;
   // Whether to mark the stack as executable.