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Re: [PATCH] PR rtl-optimization/32219: optimizer causes wrong code in pic/hidden/weak symbol checking


On Sat, Feb 07, 2015 at 03:28:38AM -0500, Jack Howarth wrote:
> H.J.,
>      The new patch bootstraps okay on x86_64-apple-darwin14 but I

Does it cause any regressions on x86_64-apple-darwin14?

> discovered that you need a small adjustment in the deja-gnu
> statements...
> 
>  --- /Users/howarth/gcc-5-20150206/gcc/testsuite/gcc.dg/visibility-22.c
> 2015-02-06 21:45:04.000000000 -0500
> +++ /sw/src/fink.build/gcc50-5.0.0-1000/gcc-5-20150206/gcc/testsuite/gcc.dg/visibility-22.c
> 2015-02-07 03:24:42.000000000 -0500
> @@ -8,9 +8,9 @@
>  /* For kernel modules and static RTPs, the loader treats undefined weak
>     symbols in the same way as undefined strong symbols.  The test
>     therefore fails to load, so skip it.  */
> +/* { dg-options "-fPIC" { target fpic } } */
>  /* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target
> *-*-darwin* } } */
>  /* { dg-additional-options "-Wl,-flat_namespace" { target
> *-*-darwin[89]* } } */
> -/* { dg-options "-fPIC" { target fpic } } */
> 
>  extern void foo () __attribute__((weak,visibility("hidden")));
>  int
> 
> If you don't define a dg-options line first, the dg-additional-options
> lines have no effect.
>                  Jack

Here is the updated patch.

H.J.
---
>From 8e61705db8177d41fac45dbeffa4faf6163d4c94 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 5 Feb 2015 14:28:58 -0800
Subject: [PATCH] Handle symbol visibility/locality for PIE/PIC

If a hidden weak symbol isn't defined in the TU, we can't assume it will
be defined in another TU at link time.  It makes a difference in code
generation when compiling for PIC. If we assume that a hidden weak
undefined symbol is local, the address checking may be optimized out and
leads to the wrong code.  This means that a symbol with user specified
visibility is local only if it is locally resolved or defined, not weak
or not compiling for PIC.  When symbol visibility is specified in the
source, we should always output symbol visibility even if symbol isn't
local to the TU.

If a global data symbol is defined in the TU, it is always local to the
executable, regardless if it is a common symbol or not.  If we aren't
compiling for shared library, locally defined global data symbol binds
locally.

gcc/

	PR rtl-optimization/32219
	* cgraphunit.c (varpool_node::finalize_decl): Set definition
	first before calling notice_global_symbol so that it is
	available to notice_global_symbol.
	* varasm.c (default_binds_local_p_1): Resolve defined data
	symbol locally if not building shared library.  Resolve symbol
	with user specified visibility locally only if it is locally
	resolved or defined, not weak or not compiling for PIC.
	(default_elf_asm_output_external): Always output visibility
	specified in the source.
	* config/darwin-protos.h (darwin_output_external): New.
	* config/darwin.c (darwin_output_external): Likewise.
	* config/darwin.h (ASM_OUTPUT_EXTERNAL): Likewise.

gcc/testsuite/

	PR rtl-optimization/32219
	* gcc.dg/visibility-22.c: New test.
	* gcc.dg/visibility-23.c: Likewise.
	* gcc.target/i386/pr32219-1.c: Likewise.
	* gcc.target/i386/pr32219-2.c: Likewise.
	* gcc.target/i386/pr32219-3.c: Likewise.
	* gcc.target/i386/pr32219-4.c: Likewise.
	* gcc.target/i386/pr32219-5.c: Likewise.
	* gcc.target/i386/pr32219-6.c: Likewise.
	* gcc.target/i386/pr32219-7.c: Likewise.
	* gcc.target/i386/pr32219-8.c: Likewise.
	* gcc.target/i386/pr64317.c: Expect GOTOFF relocation instead
	of GOT relocation.
---
 gcc/cgraphunit.c                          |  4 +++-
 gcc/config/darwin-protos.h                |  1 +
 gcc/config/darwin.c                       | 15 +++++++++++++
 gcc/config/darwin.h                       |  9 ++++++++
 gcc/testsuite/gcc.dg/visibility-22.c      | 22 +++++++++++++++++++
 gcc/testsuite/gcc.dg/visibility-23.c      | 14 +++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-1.c | 16 ++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-2.c | 16 ++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-3.c | 17 +++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-4.c | 17 +++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-5.c | 16 ++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-6.c | 16 ++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-7.c | 17 +++++++++++++++
 gcc/testsuite/gcc.target/i386/pr32219-8.c | 17 +++++++++++++++
 gcc/testsuite/gcc.target/i386/pr64317.c   |  2 +-
 gcc/varasm.c                              | 35 ++++++++++++++++++-------------
 16 files changed, 217 insertions(+), 17 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/visibility-22.c
 create mode 100644 gcc/testsuite/gcc.dg/visibility-23.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-5.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-6.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-7.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr32219-8.c

diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 35b244e..71367a3 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -792,8 +792,10 @@ varpool_node::finalize_decl (tree decl)
 
   if (node->definition)
     return;
-  notice_global_symbol (decl);
+  /* Set definition first before calling notice_global_symbol so that
+     it is available to notice_global_symbol.  */
   node->definition = true;
+  notice_global_symbol (decl);
   if (TREE_THIS_VOLATILE (decl) || DECL_PRESERVE_P (decl)
       /* Traditionally we do not eliminate static variables when not
 	 optimizing and when not doing toplevel reoder.  */
diff --git a/gcc/config/darwin-protos.h b/gcc/config/darwin-protos.h
index 249b9c1..10a77fc 100644
--- a/gcc/config/darwin-protos.h
+++ b/gcc/config/darwin-protos.h
@@ -89,6 +89,7 @@ extern tree darwin_handle_weak_import_attribute (tree *node, tree name,
 extern void machopic_output_stub (FILE *, const char *, const char *);
 extern void darwin_globalize_label (FILE *, const char *);
 extern void darwin_assemble_visibility (tree, int);
+extern void darwin_output_external (FILE *, tree, const char *name);
 
 extern void darwin_asm_output_dwarf_delta (FILE *, int, const char *,
 					   const char *);
diff --git a/gcc/config/darwin.c b/gcc/config/darwin.c
index 40804b8..5025ef7 100644
--- a/gcc/config/darwin.c
+++ b/gcc/config/darwin.c
@@ -2762,6 +2762,21 @@ darwin_assemble_visibility (tree decl, int vis)
 	     "not supported in this configuration; ignored");
 }
 
+/* Emit text to declare externally defined symbols.  Used to support
+   undefined hidden visibility with Darwin's private extern feature.  */
+
+void
+darwin_output_external (FILE *file ATTRIBUTE_UNUSED, tree decl,
+			const char *name ATTRIBUTE_UNUSED)
+{
+  /* We output the name if and only if TREE_SYMBOL_REFERENCED is set and
+     visibility is specified in the source in order to avoid putting out
+     names that are never really used.  */
+  if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
+      && DECL_VISIBILITY_SPECIFIED (decl))
+    darwin_assemble_visibility (decl, DECL_VISIBILITY (decl));
+}
+
 /* vec used by darwin_asm_dwarf_section.
    Maybe a hash tab would be better here - but the intention is that this is
    a very short list (fewer than 16 items) and each entry should (ideally, 
diff --git a/gcc/config/darwin.h b/gcc/config/darwin.h
index b61dbb5..c9a1b34 100644
--- a/gcc/config/darwin.h
+++ b/gcc/config/darwin.h
@@ -700,6 +700,15 @@ extern GTY(()) section * darwin_sections[NUM_DARWIN_SECTIONS];
 #undef TARGET_ASM_ASSEMBLE_VISIBILITY
 #define TARGET_ASM_ASSEMBLE_VISIBILITY darwin_assemble_visibility
 
+/* A C statement (sans semicolon) to output to the stdio stream STREAM
+   any text necessary for declaring the name of an external symbol
+   named NAME which is referenced in this compilation but not defined.
+   Used to support undefined hidden visibility with Darwin's private
+   extern feature.  */
+
+#undef ASM_OUTPUT_EXTERNAL
+#define ASM_OUTPUT_EXTERNAL darwin_output_external
+
 /* Extra attributes for Darwin.  */
 #define SUBTARGET_ATTRIBUTE_TABLE					     \
   /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler,     \
diff --git a/gcc/testsuite/gcc.dg/visibility-22.c b/gcc/testsuite/gcc.dg/visibility-22.c
new file mode 100644
index 0000000..a118a6e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/visibility-22.c
@@ -0,0 +1,22 @@
+/* PR target/32219 */
+/* { dg-do run } */
+/* { dg-require-visibility "" } */
+/* { dg-options "-O2 -fPIC" { target fpic } } */
+/* This test requires support for undefined weak symbols.  This support
+   is not available on hppa*-*-hpux*.  The test is skipped rather than
+   xfailed to suppress the warning that would otherwise arise.  */
+/* { dg-skip-if "" { "hppa*-*-hpux*" "*-*-aix*" } "*" { "" } }  */
+/* For kernel modules and static RTPs, the loader treats undefined weak
+   symbols in the same way as undefined strong symbols.  The test
+   therefore fails to load, so skip it.  */
+/* { dg-additional-options "-Wl,-undefined,dynamic_lookup" { target *-*-darwin* } } */
+/* { dg-additional-options "-Wl,-flat_namespace" { target *-*-darwin[89]* } } */
+
+extern void foo () __attribute__((weak,visibility("hidden")));
+int
+main()
+{
+  if (foo)
+    foo ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/visibility-23.c b/gcc/testsuite/gcc.dg/visibility-23.c
new file mode 100644
index 0000000..347578e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/visibility-23.c
@@ -0,0 +1,14 @@
+/* PR target/32219 */
+/* { dg-do compile } */
+/* { dg-require-visibility "" } */
+/* { dg-final { scan-hidden "foo" } } */
+/* { dg-options "-O2 -fPIC" { target fpic } } */
+
+extern void foo () __attribute__((weak,visibility("hidden")));
+int
+main()
+{
+  if (foo)
+    foo ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-1.c b/gcc/testsuite/gcc.target/i386/pr32219-1.c
new file mode 100644
index 0000000..5bd80a0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-1.c
@@ -0,0 +1,16 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpie" } */
+
+/* Common symbol with -fpie.  */
+int xxx;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-2.c b/gcc/testsuite/gcc.target/i386/pr32219-2.c
new file mode 100644
index 0000000..0cf2eb5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpic" } */
+
+/* Common symbol with -fpic.  */
+int xxx;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-3.c b/gcc/testsuite/gcc.target/i386/pr32219-3.c
new file mode 100644
index 0000000..911f2a5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-3.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpie" } */
+
+/* Weak common symbol with -fpie.  */
+__attribute__((weak))
+int xxx;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-4.c b/gcc/testsuite/gcc.target/i386/pr32219-4.c
new file mode 100644
index 0000000..3d43439
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-4.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpic" } */
+
+/* Weak common symbol with -fpic.  */
+__attribute__((weak))
+int xxx;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-5.c b/gcc/testsuite/gcc.target/i386/pr32219-5.c
new file mode 100644
index 0000000..ee7442e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-5.c
@@ -0,0 +1,16 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpie" } */
+
+/* Initialized symbol with -fpie.  */
+int xxx = -1;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-6.c b/gcc/testsuite/gcc.target/i386/pr32219-6.c
new file mode 100644
index 0000000..f261433
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-6.c
@@ -0,0 +1,16 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpic" } */
+
+/* Initialized symbol with -fpic.  */
+int xxx = -1;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-7.c b/gcc/testsuite/gcc.target/i386/pr32219-7.c
new file mode 100644
index 0000000..12aaf72
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-7.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpie" } */
+
+/* Weak initialized symbol with -fpie.  */
+__attribute__((weak))
+int xxx = -1;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr32219-8.c b/gcc/testsuite/gcc.target/i386/pr32219-8.c
new file mode 100644
index 0000000..2e4fba0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr32219-8.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fpic" } */
+
+/* Weak initialized symbol with -fpic.  */
+__attribute__((weak))
+int xxx = -1;
+
+int
+foo ()
+{
+  return xxx;
+}
+
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx\\(%rip\\), %eax" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "xxx@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]xxx@GOTOFF\\(%\[^,\]*\\), %eax" { target ia32 } } } */
+/* { dg-final { scan-assembler "movl\[ \t\]xxx@GOT\\(%\[^,\]*\\), %eax" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr64317.c b/gcc/testsuite/gcc.target/i386/pr64317.c
index 33f5b5d..32969fc 100644
--- a/gcc/testsuite/gcc.target/i386/pr64317.c
+++ b/gcc/testsuite/gcc.target/i386/pr64317.c
@@ -1,7 +1,7 @@
 /* { dg-do compile { target { *-*-linux* && ia32 } } } */
 /* { dg-options "-O2 -fpie" } */
 /* { dg-final { scan-assembler "addl\[ \\t\]+\[$\]_GLOBAL_OFFSET_TABLE_, %ebx" } } */
-/* { dg-final { scan-assembler "movl\[ \\t\]+c@GOT\[(\]%ebx\[)\]" } } */
+/* { dg-final { scan-assembler "movl\[ \\t\]+c@GOTOFF\[(\]%ebx\[)\]" } } */
 /* { dg-final { scan-assembler-not "movl\[ \\t\]+\[0-9]+\[(\]%esp\[)\], %ebx" } } */
 long c;
 
diff --git a/gcc/varasm.c b/gcc/varasm.c
index eb65b1f..f7c13af 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -6826,11 +6826,17 @@ default_binds_local_p_1 (const_tree exp, int shlib)
       && (TREE_STATIC (exp) || DECL_EXTERNAL (exp)))
     {
       varpool_node *vnode = varpool_node::get (exp);
-      if (vnode && (resolution_local_p (vnode->resolution) || vnode->in_other_partition))
-	resolved_locally = true;
-      if (vnode
-	  && resolution_to_local_definition_p (vnode->resolution))
-	resolved_to_local_def = true;
+      /* If not building shared library, common or initialized symbols
+	 are also resolved locally, regardless they are weak or not.  */
+      if (vnode)
+	{
+	  if ((!shlib && vnode->definition)
+	      || vnode->in_other_partition
+	      || resolution_local_p (vnode->resolution))
+	    resolved_locally = true;
+	  if (resolution_to_local_definition_p (vnode->resolution))
+	    resolved_to_local_def = true;
+	}
     }
   else if (TREE_CODE (exp) == FUNCTION_DECL && TREE_PUBLIC (exp))
     {
@@ -6859,9 +6865,14 @@ default_binds_local_p_1 (const_tree exp, int shlib)
   else if (! TREE_PUBLIC (exp))
     local_p = true;
   /* A variable is local if the user has said explicitly that it will
-     be.  */
+     be and it is resolved or defined locally, not compiling for PIC or
+     not weak.  */
   else if ((DECL_VISIBILITY_SPECIFIED (exp)
 	    || resolved_to_local_def)
+	   && (resolved_locally
+	       || !flag_pic
+	       || !DECL_EXTERNAL (exp)
+	       || !DECL_WEAK (exp))
 	   && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
     local_p = true;
   /* Variables defined outside this object might not be local.  */
@@ -6880,13 +6891,6 @@ default_binds_local_p_1 (const_tree exp, int shlib)
      symbols resolved from other modules.  */
   else if (shlib)
     local_p = false;
-  /* Uninitialized COMMON variable may be unified with symbols
-     resolved from other modules.  */
-  else if (DECL_COMMON (exp)
-	   && !resolved_locally
-	   && (DECL_INITIAL (exp) == NULL
-	       || (!in_lto_p && DECL_INITIAL (exp) == error_mark_node)))
-    local_p = false;
   /* Otherwise we're left with initialized (or non-common) global data
      which is of necessity defined locally.  */
   else
@@ -7445,9 +7449,10 @@ default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
 {
   /* We output the name if and only if TREE_SYMBOL_REFERENCED is
      set in order to avoid putting out names that are never really
-     used. */
+     used.   Always output visibility specified in the source.  */
   if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
-      && targetm.binds_local_p (decl))
+      && (DECL_VISIBILITY_SPECIFIED (decl)
+	  || targetm.binds_local_p (decl)))
     maybe_assemble_visibility (decl);
 }
 
-- 
2.1.0


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