binutils/binutils-pr24486.patch

From c54f15248ee990df6cea0b4730cd61b227a0e082 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 26 Apr 2019 07:52:00 -0700
Subject: [PATCH] Don't complain undefined weak dynamic reference

When undefined non-weak references in IR objects are optimized out
by LTO, we can have weak dynamic referencs to symbols marked with
bfd_link_hash_undefined.  We shouldn't complain such undefined weak
dynamic references.

bfd/

	PR ld/24486
	* elflink.c (elf_link_output_extsym): Don't complain undefined
	weak dynamic reference.

ld/

	PR ld/24486
	* testsuite/ld-plugin/lto.exp: Run PR ld/24486 tests.
	* testsuite/ld-plugin/pr24486a.c: New file.
	* testsuite/ld-plugin/pr24486b.c: Likewise.
	* testsuite/ld-plugin/pr24486c.c: Likewise.
---
 bfd/ChangeLog                     |  6 ++++++
 bfd/elflink.c                     |  2 +-
 ld/ChangeLog                      |  8 ++++++++
 ld/testsuite/ld-plugin/lto.exp    | 12 ++++++++++++
 ld/testsuite/ld-plugin/pr24486a.c |  8 ++++++++
 ld/testsuite/ld-plugin/pr24486b.c |  8 ++++++++
 ld/testsuite/ld-plugin/pr24486c.c |  1 +
 7 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 ld/testsuite/ld-plugin/pr24486a.c
 create mode 100644 ld/testsuite/ld-plugin/pr24486b.c
 create mode 100644 ld/testsuite/ld-plugin/pr24486c.c

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 81e667dab0..ddeaa08d50 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -9776,7 +9776,7 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
 
       /* If we are reporting errors for this situation then do so now.  */
       if (!ignore_undef
-	  && h->ref_dynamic
+	  && h->ref_dynamic_nonweak
 	  && (!h->ref_regular || flinfo->info->gc_sections)
 	  && !elf_link_check_versioned_symbol (flinfo->info, bed, h)
 	  && flinfo->info->unresolved_syms_in_shared_libs != RM_IGNORE)
diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index b13a77333f..e913c6f203 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -325,6 +325,18 @@ set lto_link_elf_tests [list \
   [list {Build pr22220main.o} \
    {} {-flto} \
    {pr22220main.cc} {} {} {c++}] \
+  [list "Build pr24486a.o" \
+   "$plug_opt" "-flto -O2" \
+   {pr24486a.c} {} "" "c"] \
+  [list "Build pr24486b.so" \
+   "-shared" "-O2 -fpic" \
+   {pr24486b.c} {} "pr24486b.so" "c"] \
+  [list "Build pr24486c.so" \
+   "-shared -Wl,--no-as-needed tmpdir/pr24486b.so" "-O2 -fpic" \
+   {pr24486c.c} {} "pr24486c.so" "c"] \
+  [list "PR ld/24486" \
+   "-O2 -flto tmpdir/pr24486a.o tmpdir/pr24486c.so -Wl,--as-needed tmpdir/pr24486b.so" "" \
+   {dummy.c} {} "pr24486.exe"] \
 ]
 
 # PR 14918 checks that libgcc is not spuriously included in a shared link of
diff --git a/ld/testsuite/ld-plugin/pr24486a.c b/ld/testsuite/ld-plugin/pr24486a.c
new file mode 100644
index 0000000000..def0139598
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr24486a.c
@@ -0,0 +1,8 @@
+extern int FLAGS_verbose;
+extern void bar (void);
+int
+a(void) {
+return FLAGS_verbose;
+}
+void unused (void) { bar(); }
+int main() { return a (); }
diff --git a/ld/testsuite/ld-plugin/pr24486b.c b/ld/testsuite/ld-plugin/pr24486b.c
new file mode 100644
index 0000000000..3aabe2a395
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr24486b.c
@@ -0,0 +1,8 @@
+extern void bar (void) __attribute__((weak));
+
+void
+foo (void)
+{
+  if (bar)
+    bar ();
+}
diff --git a/ld/testsuite/ld-plugin/pr24486c.c b/ld/testsuite/ld-plugin/pr24486c.c
new file mode 100644
index 0000000000..f289177d3e
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr24486c.c
@@ -0,0 +1 @@
+int FLAGS_verbose;
-- 
2.21.0