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 7e9fb6837c53d19915fc45206500b95d0ee70bac..0959688f616d7e285ace4ab9d1afe1293632444f 100644 (file)
--- 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 87440db9605551795b645561ce12693360274e0c..4eca389bd184a2e25dc0bef71bdcc2ef842134ef 100644 (file)
--- 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 f0a373d036b087c43f848d0c842d8dbb317e5527..60265758c7fe572f294838cf55881a0e8928b9f9 100644 (file)
--- 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 18829fdd64a5ea8f4cb4305488ca826dad5ad7b4..008bde79de7733825d43a300d5aa2074d47ba264 100644 (file)
--- 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 (file)
index 0000000..5753cd6
--- /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 (file)
index 0000000..45bca55
--- /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 (file)
index 0000000..5b5ccbf
--- /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 (file)
index 0000000..d4be333
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr23818b.c
@@ -0,0 +1,7 @@
+void foo (void);
+
+void
+bar (void)
+{
+  foo ();
+}