[PATCH] gold: Remove GNU ld incompatible --[no-]define-common [BZ #28871]

[Fangrui Song <maskray@google.com>]

In 2008, 0dfbdef4c43cfe12bb3e2505ebe5acc651a35c98 confused
--define-common with -d/FORCE_COMMON_ALLOCATION and implemented
--define-common with -d semantics.

Just remove the GNU ld incompatible --[no-]define-common.
---
 gold/gold.cc    |  2 +-
 gold/options.cc | 14 ++++----------
 gold/options.h  |  9 ++++-----
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/gold/gold.cc b/gold/gold.cc
index 2891d16c7c9..a93489e225e 100644
--- a/gold/gold.cc
+++ b/gold/gold.cc
@@ -708,7 +708,7 @@ queue_middle_tasks(const General_options& options,
   // Allocate common symbols.  We use a blocker to run this before the
   // Scan_relocs tasks, because it writes to the symbol table just as
   // they do.
-  if (parameters->options().define_common())
+  if (parameters->options().dc())
     {
       this_blocker = new Task_token(true);
       this_blocker->add_blocker();
diff --git a/gold/options.cc b/gold/options.cc
index 04be98a3e39..a6c4bda1ae8 100644
--- a/gold/options.cc
+++ b/gold/options.cc
@@ -1136,16 +1136,10 @@ General_options::finalize()
       gold_assert(this->strip_debug());
     }
 
-  // For us, -dc and -dp are synonyms for --define-common.
-  if (this->dc())
-    this->set_define_common(true);
-  if (this->dp())
-    this->set_define_common(true);
-
-  // We also set --define-common if we're not relocatable, as long as
-  // the user didn't explicitly ask for something different.
-  if (!this->user_set_define_common())
-    this->set_define_common(!this->relocatable());
+  // A non-relocatable link always allocates space to COMMON symbols.
+  // -dc, -d, and -dp can force allocation for a relocatable link.
+  if (!this->relocatable() || this->d() || this->dp())
+    this->set_dc(true);
 
   // execstack_status_ is a three-state variable; update it based on
   // -z [no]execstack.
diff --git a/gold/options.h b/gold/options.h
index 9509a445e8e..a994bdcf42a 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -787,13 +787,12 @@ class General_options
 
   // d
 
-  DEFINE_bool(define_common, options::TWO_DASHES, 'd', false,
-	      N_("Define common symbols"),
-	      N_("Do not define common symbols in relocatable output"));
   DEFINE_bool(dc, options::ONE_DASH, '\0', false,
-	      N_("Alias for -d"), NULL);
+    N_("Allocate space to COMMON symbols for the relocatable link"), NULL);
+  DEFINE_bool(d, options::ONE_DASH, '\0', false,
+	      N_("Alias for -dc"), NULL);
   DEFINE_bool(dp, options::ONE_DASH, '\0', false,
-	      N_("Alias for -d"), NULL);
+	      N_("Alias for -dc"), NULL);
 
   DEFINE_string(debug, options::TWO_DASHES, '\0', "",
 		N_("Turn on debugging"),
-- 
2.35.0.263.gb82422642f-goog