Fix corrupted .eh_frame section with LTO and --gc-sections.

When --gc-sections is turned on during an LTO link, the .eh_frame sections
from deferred files are processed before those from the replacement files.
As a result, the section end-cap from crtendS.o is placed ahead of
the .eh_frame data from the replacement files. This patch fixes the bug
by skipping the layout of the deferred sections during GC pass 2.

gold/
	PR gold/17639
	* object.cc (Sized_relobj_file): Initialize is_deferred_layout_.
	(Sized_relobj_file::do_layout): Handle deferred sections properly
	during GC pass 1. Don't add reloc sections to deferred list twice.
	* object.h (Sized_relobj_file::is_deferred_layout): New function.
	(Sized_relobj_file::is_deferred_layout_): New data member.

1 files changed, 7 insertions, 0 deletions

diff --git a/gold/object.h b/gold/object.h
index 754b1d26b89..cf45ec53e47 100644
--- a/gold/object.h
+++ b/gold/object.h
@@ -2202,6 +2202,10 @@ class Sized_relobj_file : public Sized_relobj<size, big_endian>
 			    Symbol_value<size>* lv_out,
 			    const Symbol_table* symtab);
 
+  // Return true if the layout for this object was deferred.
+  bool is_deferred_layout() const
+  { return this->is_deferred_layout_; }
+
  protected:
   typedef typename Sized_relobj<size, big_endian>::Output_sections
       Output_sections;
@@ -2740,6 +2744,9 @@ class Sized_relobj_file : public Sized_relobj<size, big_endian>
   // If this object has a GNU style .eh_frame section that is discarded in
   // output, record the index here.  Otherwise it is -1U.
   unsigned int discarded_eh_frame_shndx_;
+  // True if the layout of this object was deferred, waiting for plugin
+  // replacement files.
+  bool is_deferred_layout_;
   // The list of sections whose layout was deferred.
   std::vector<Deferred_layout> deferred_layout_;
   // The list of relocation sections whose layout was deferred.