From: H.J. Lu <hjl.tools@gmail.com>
Date: Thu, 25 Oct 2018 01:08:13 +0000 (-0700)
Subject: ELF: Hide symbols defined in discarded input sections
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=0a640d719684f25bdb88ae60148c6978e6131701;p=deliverable%2Fbinutils-gdb.git

ELF: Hide symbols defined in discarded input sections

When assigning symbol version, we should hide debug symbols defined in
discarded sections from IR objects so that they can be removed later.

bfd/

	PR ld/23818
	* elflink.c (_bfd_elf_link_assign_sym_version): Hide symbols
	defined in discarded input sections.

ld/

	PR ld/23818
	* testsuite/ld-plugin/lto.exp: Run PR ld/23818 test.
	* testsuite/ld-plugin/pr23818.d: New file.
	* testsuite/ld-plugin/pr23818.t: Likewise.
	* testsuite/ld-plugin/pr23818a.c: Likewise.
	* testsuite/ld-plugin/pr23818b.c: Likewise.
---

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 7e9fb6837c..0959688f61 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2018-10-24  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/23818
+	* elflink.c (_bfd_elf_link_assign_sym_version): Hide symbols
+	defined in discarded input sections.
+
 2018-10-24  Alan Modra  <amodra@gmail.com>
 
 	* elf32-arm.c (elf32_arm_size_stubs): Ignore as-needed libs that
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 87440db960..4eca389bd1 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2359,13 +2359,21 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
       return FALSE;
     }
 
+  bed = get_elf_backend_data (info->output_bfd);
+
   /* We only need version numbers for symbols defined in regular
      objects.  */
   if (!h->def_regular)
-    return TRUE;
+    {
+      /* Hide symbols defined in discarded input sections.  */
+      if ((h->root.type == bfd_link_hash_defined
+	   || h->root.type == bfd_link_hash_defweak)
+	  && discarded_section (h->root.u.def.section))
+	(*bed->elf_backend_hide_symbol) (info, h, TRUE);
+      return TRUE;
+    }
 
   hide = FALSE;
-  bed = get_elf_backend_data (info->output_bfd);
   p = strchr (h->root.root.string, ELF_VER_CHR);
   if (p != NULL && h->verinfo.vertree == NULL)
     {
diff --git a/ld/ChangeLog b/ld/ChangeLog
index f0a373d036..60265758c7 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,12 @@
+2018-10-24  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/23818
+	* testsuite/ld-plugin/lto.exp: Run PR ld/23818 test.
+	* testsuite/ld-plugin/pr23818.d: New file.
+	* testsuite/ld-plugin/pr23818.t: Likewise.
+	* testsuite/ld-plugin/pr23818a.c: Likewise.
+	* testsuite/ld-plugin/pr23818b.c: Likewise.
+
 2018-10-23  Alan Modra  <amodra@gmail.com>
 
 	* testsuite/ld-elf/shared.exp: Don't build pr19073 test on alpha.
diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index 18829fdd64..008bde79de 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -219,6 +219,12 @@ set lto_link_tests [list \
   [list "Build pr22751.a" \
    "$plug_opt" "-flto $lto_no_fat $INT128_CFLAGS" \
    {pr22751.c} {} "pr22751.a"] \
+  [list "Build libpr23818.so" \
+   "-shared -flto -g -Wl,-version-script,pr23818.t" \
+   "-g -flto $lto_fat" \
+   {pr23818a.c pr23818b.c} \
+   {{"readelf" {-s --wide} "pr23818.d"}} \
+   "libpr23818.so"] \
 ]
 
 if { [at_least_gcc_version 4 7] } {
diff --git a/ld/testsuite/ld-plugin/pr23818.d b/ld/testsuite/ld-plugin/pr23818.d
new file mode 100644
index 0000000000..5753cd64fd
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr23818.d
@@ -0,0 +1,4 @@
+#failif
+#...
+.*0+ +[A-Z]+ +GLOBAL +DEFAULT +ABS foo
+#...
diff --git a/ld/testsuite/ld-plugin/pr23818.t b/ld/testsuite/ld-plugin/pr23818.t
new file mode 100644
index 0000000000..45bca5580e
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr23818.t
@@ -0,0 +1,4 @@
+{
+  global: bar;
+  local: *;
+};
diff --git a/ld/testsuite/ld-plugin/pr23818a.c b/ld/testsuite/ld-plugin/pr23818a.c
new file mode 100644
index 0000000000..5b5ccbf7cb
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr23818a.c
@@ -0,0 +1,4 @@
+void
+foo ()
+{
+}
diff --git a/ld/testsuite/ld-plugin/pr23818b.c b/ld/testsuite/ld-plugin/pr23818b.c
new file mode 100644
index 0000000000..d4be333a39
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr23818b.c
@@ -0,0 +1,7 @@
+void foo (void);
+
+void
+bar (void)
+{
+  foo ();
+}