diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index a561aaf3100..3613f8252a7 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -1609,6 +1609,19 @@ set_comp_unit (struct objfile *objfile, struct comp_unit *unit)
   return dwarf2_frame_bfd_data.set (abfd, unit);
 }
 
+/* See frame.h.  */
+
+void
+dwarf2_clear_frame_data (struct objfile *objfile)
+{
+  bfd *abfd = objfile->obfd.get ();
+
+  if (gdb_bfd_requires_relocations (abfd))
+    dwarf2_frame_objfile_data.clear (objfile);
+  else
+    dwarf2_frame_bfd_data.clear (abfd);
+}
+
 /* Find the FDE for *PC.  Return a pointer to the FDE, and store the
    initial location associated with it into *PC.  */
 
diff --git a/gdb/dwarf2/frame.h b/gdb/dwarf2/frame.h
index 5643e557513..2391e313e7c 100644
--- a/gdb/dwarf2/frame.h
+++ b/gdb/dwarf2/frame.h
@@ -238,6 +238,10 @@ void dwarf2_append_unwinders (struct gdbarch *gdbarch);
 extern const struct frame_base *
   dwarf2_frame_base_sniffer (frame_info_ptr this_frame);
 
+/* Delete OBJFILEs comp_unit.  */
+
+extern void dwarf2_clear_frame_data (struct objfile * objfile);
+
 /* Compute the DWARF CFA for a frame.  */
 
 CORE_ADDR dwarf2_frame_cfa (frame_info_ptr this_frame);
diff --git a/gdb/dwarf2/index-cache.c b/gdb/dwarf2/index-cache.c
index 79ab706ee9d..bbafcd321b2 100644
--- a/gdb/dwarf2/index-cache.c
+++ b/gdb/dwarf2/index-cache.c
@@ -216,6 +216,33 @@ index_cache::lookup_gdb_index (const bfd_build_id *build_id,
   return {};
 }
 
+/* See index-cache.h.  */
+
+gdb::array_view<const gdb_byte>
+index_cache::lookup_gdb_index_debuginfod (const char *index_path,
+					  std::unique_ptr<index_cache_resource> *resource)
+{
+  try
+    {
+      /* Try to map that file.  */
+      index_cache_resource_mmap *mmap_resource
+	= new index_cache_resource_mmap (index_path);
+
+      /* Hand the resource to the caller.  */
+      resource->reset (mmap_resource);
+
+      return gdb::array_view<const gdb_byte>
+	  ((const gdb_byte *) mmap_resource->mapping.get (),
+	   mmap_resource->mapping.size ());
+    }
+  catch (const gdb_exception_error &except)
+    {
+      warning (_("Unable to read %s: %s"), index_path, except.what ());
+    }
+
+  return {};
+}
+
 #else /* !HAVE_SYS_MMAN_H */
 
 /* See dwarf-index-cache.h.  This is a no-op on unsupported systems.  */
@@ -227,6 +254,12 @@ index_cache::lookup_gdb_index (const bfd_build_id *build_id,
   return {};
 }
 
+gdb::array_view<const gdb_byte>
+index_cache::lookup_gdb_index_debuginfod (const char *index_path,
+					  std::unique_ptr<index_cache_resource> *resource)
+{
+  return {};
+}
 #endif
 
 /* See dwarf-index-cache.h.  */
diff --git a/gdb/dwarf2/index-cache.h b/gdb/dwarf2/index-cache.h
index 1efff17049f..e400afd5123 100644
--- a/gdb/dwarf2/index-cache.h
+++ b/gdb/dwarf2/index-cache.h
@@ -67,6 +67,19 @@ class index_cache
   lookup_gdb_index (const bfd_build_id *build_id,
 		    std::unique_ptr<index_cache_resource> *resource);
 
+  /* Look for an index file located at INDEX_PATH in the debuginfod cache.
+     Unlike lookup_gdb_index, this function does not exit early if the
+     index cache has not been enabled.
+
+     If found, return the contents as an array_view and store the underlying
+     resources (allocated memory, mapped file, etc) in RESOURCE.  The returned
+     array_view is valid as long as RESOURCE is not destroyed.
+
+     If no matching index file is found, return an empty array view.  */
+  gdb::array_view<const gdb_byte>
+  lookup_gdb_index_debuginfod (const char *index_path,
+			       std::unique_ptr<index_cache_resource> *resource);
+
   /* Return the number of cache hits.  */
   unsigned int n_hits () const
   { return m_n_hits; }
diff --git a/gdb/dwarf2/public.h b/gdb/dwarf2/public.h
index 0e74857eb1a..4a44cdbc223 100644
--- a/gdb/dwarf2/public.h
+++ b/gdb/dwarf2/public.h
@@ -40,4 +40,11 @@ extern void dwarf2_initialize_objfile (struct objfile *objfile);
 
 extern void dwarf2_build_frame_info (struct objfile *);
 
+/* Query debuginfod for the .gdb_index associated with OBJFILE.  If
+   successful, create an objfile to hold the .gdb_index information
+   and act as a placeholder until the full debuginfo needs to be
+   downloaded.  */
+
+extern bool dwarf2_has_separate_index (struct objfile *);
+
 #endif /* DWARF2_PUBLIC_H */
diff --git a/gdb/dwarf2/read-gdb-index.c b/gdb/dwarf2/read-gdb-index.c
index 1006386cb2d..d3516e92361 100644
--- a/gdb/dwarf2/read-gdb-index.c
+++ b/gdb/dwarf2/read-gdb-index.c
@@ -136,6 +136,7 @@ struct dwarf2_gdb_index : public dwarf2_base_index_functions
      gdb.dwarf2/gdb-index.exp testcase.  */
   void dump (struct objfile *objfile) override;
 
+  /* Calls do_expand_matching_symbols and downloads debuginfo if necessary.  */
   void expand_matching_symbols
     (struct objfile *,
      const lookup_name_info &lookup_name,
@@ -143,6 +144,14 @@ struct dwarf2_gdb_index : public dwarf2_base_index_functions
      int global,
      symbol_compare_ftype *ordered_compare) override;
 
+  void do_expand_matching_symbols
+    (struct objfile *,
+     const lookup_name_info &lookup_name,
+     domain_enum domain,
+     int global,
+     symbol_compare_ftype *ordered_compare);
+
+  /* Calls do_expand_symtabs_matching and downloads debuginfo if necessary.  */
   bool expand_symtabs_matching
     (struct objfile *objfile,
      gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
@@ -152,8 +161,59 @@ struct dwarf2_gdb_index : public dwarf2_base_index_functions
      block_search_flags search_flags,
      domain_enum domain,
      enum search_domain kind) override;
+
+  bool do_expand_symtabs_matching
+    (struct objfile *objfile,
+     gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
+     const lookup_name_info *lookup_name,
+     gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
+     gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
+     block_search_flags search_flags,
+     domain_enum domain,
+     enum search_domain kind);
+
+  /* Calls dwarf2_base_index_functions::expand_all_symtabs and downloads
+     debuginfo if necessary.  */
+  void expand_all_symtabs (struct objfile *objfile) override;
+
+  /* Calls dwarf2_base_index_functions::find_last_source_symtab and downloads
+     debuginfo if necessary.  */
+  struct symtab *find_last_source_symtab (struct objfile *objfile) override;
 };
 
+void
+dwarf2_gdb_index::expand_all_symtabs (struct objfile *objfile)
+{
+  try
+    {
+      dwarf2_base_index_functions::expand_all_symtabs (objfile);
+    }
+  catch (gdb_exception e)
+    {
+      if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED) == 0)
+	exception_print (gdb_stderr, e);
+      else
+	read_full_dwarf_from_debuginfod (objfile, this);
+    }
+}
+
+struct symtab *
+dwarf2_gdb_index::find_last_source_symtab (struct objfile *objfile)
+{
+  try
+    {
+      return dwarf2_base_index_functions::find_last_source_symtab (objfile);
+    }
+  catch (gdb_exception e)
+    {
+      if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED) == 0)
+	exception_print (gdb_stderr, e);
+      else
+	read_full_dwarf_from_debuginfod (objfile, this);
+      return nullptr;
+    }
+}
+
 /* This dumps minimal information about the index.
    It is called via "mt print objfiles".
    One use is to verify .gdb_index has been loaded by the
@@ -315,7 +375,7 @@ dw2_symtab_iter_next (struct dw2_symtab_iterator *iter,
 }
 
 void
-dwarf2_gdb_index::expand_matching_symbols
+dwarf2_gdb_index::do_expand_matching_symbols
   (struct objfile *objfile,
    const lookup_name_info &name, domain_enum domain,
    int global,
@@ -353,6 +413,29 @@ dwarf2_gdb_index::expand_matching_symbols
     }, per_objfile);
 }
 
+void
+dwarf2_gdb_index::expand_matching_symbols
+  (struct objfile *objfile,
+   const lookup_name_info &lookup_name,
+   domain_enum domain,
+   int global,
+   symbol_compare_ftype *ordered_compare)
+{
+  try
+    {
+      do_expand_matching_symbols (objfile, lookup_name, domain,
+				  global, ordered_compare);
+    }
+  catch (gdb_exception e)
+    {
+      if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED) == 0)
+	exception_print (gdb_stderr, e);
+      else
+	read_full_dwarf_from_debuginfod (objfile, this);
+      return;
+    }
+}
+
 /* Helper for dw2_expand_matching symtabs.  Called on each symbol
    matched, to expand corresponding CUs that were marked.  IDX is the
    index of the symbol name that matched.  */
@@ -455,7 +538,7 @@ dw2_expand_marked_cus
 }
 
 bool
-dwarf2_gdb_index::expand_symtabs_matching
+dwarf2_gdb_index::do_expand_symtabs_matching
     (struct objfile *objfile,
      gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
      const lookup_name_info *lookup_name,
@@ -504,6 +587,39 @@ dwarf2_gdb_index::expand_symtabs_matching
   return result;
 }
 
+bool
+dwarf2_gdb_index::expand_symtabs_matching
+    (struct objfile *objfile,
+     gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
+     const lookup_name_info *lookup_name,
+     gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
+     gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
+     block_search_flags search_flags,
+     domain_enum domain,
+     enum search_domain kind)
+{
+  if (objfile->flags & OBJF_READNEVER)
+    return false;
+
+  try
+    {
+      return do_expand_symtabs_matching (objfile, file_matcher, lookup_name,
+					 symbol_matcher, expansion_notify,
+					 search_flags, domain, kind);
+    }
+  catch (gdb_exception e)
+    {
+      if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED) == 0)
+	{
+	  exception_print (gdb_stderr, e);
+	  return false;
+	}
+
+      read_full_dwarf_from_debuginfod (objfile, this);
+      return true;
+    }
+}
+
 quick_symbol_functions_up
 mapped_gdb_index::make_quick_functions () const
 {
@@ -797,28 +913,32 @@ dwarf2_read_gdb_index
 
   /* If there is a .dwz file, read it so we can get its CU list as
      well.  */
-  dwz = dwarf2_get_dwz_file (per_bfd);
-  if (dwz != NULL)
+  if (get_gdb_index_contents_dwz != nullptr)
     {
       mapped_gdb_index dwz_map;
       const gdb_byte *dwz_types_ignore;
       offset_type dwz_types_elements_ignore;
+      dwz = dwarf2_get_dwz_file (per_bfd);
 
-      gdb::array_view<const gdb_byte> dwz_index_content
-	= get_gdb_index_contents_dwz (objfile, dwz);
-
-      if (dwz_index_content.empty ())
-	return 0;
-
-      if (!read_gdb_index_from_buffer (bfd_get_filename (dwz->dwz_bfd.get ()),
-				       1, dwz_index_content, &dwz_map,
-				       &dwz_list, &dwz_list_elements,
-				       &dwz_types_ignore,
-				       &dwz_types_elements_ignore))
+      if (dwz != nullptr)
 	{
-	  warning (_("could not read '.gdb_index' section from %s; skipping"),
-		   bfd_get_filename (dwz->dwz_bfd.get ()));
-	  return 0;
+	  gdb::array_view<const gdb_byte> dwz_index_content
+	    = get_gdb_index_contents_dwz (objfile, dwz);
+
+	  if (dwz_index_content.empty ())
+	    return 0;
+
+	  if (!read_gdb_index_from_buffer (bfd_get_filename
+					     (dwz->dwz_bfd.get ()),
+					   1, dwz_index_content, &dwz_map,
+					   &dwz_list, &dwz_list_elements,
+					   &dwz_types_ignore,
+					   &dwz_types_elements_ignore))
+	    {
+	      warning (_("could not read '.gdb_index' section from %s; skipping"),
+		       bfd_get_filename (dwz->dwz_bfd.get ()));
+		return 0;
+	    }
 	}
     }
 
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 29a95cb8b2f..185a999ccee 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -34,6 +34,7 @@
 #include "dwarf2/attribute.h"
 #include "dwarf2/comp-unit-head.h"
 #include "dwarf2/cu.h"
+#include "dwarf2/frame.h"
 #include "dwarf2/index-cache.h"
 #include "dwarf2/index-common.h"
 #include "dwarf2/leb.h"
@@ -95,6 +96,8 @@
 #include "split-name.h"
 #include "gdbsupport/parallel-for.h"
 #include "gdbsupport/thread-pool.h"
+#include "inferior.h"
+#include "debuginfod-support.h"
 
 /* When == 1, print basic high level tracing messages.
    When > 1, be more verbose.
@@ -3163,7 +3166,7 @@ dwarf2_base_index_functions::find_per_cu (dwarf2_per_bfd *per_bfd,
 }
 
 struct compunit_symtab *
-dwarf2_base_index_functions::find_pc_sect_compunit_symtab
+dwarf2_base_index_functions::do_find_pc_sect_compunit_symtab
      (struct objfile *objfile,
       struct bound_minimal_symbol msymbol,
       CORE_ADDR pc,
@@ -3194,6 +3197,32 @@ dwarf2_base_index_functions::find_pc_sect_compunit_symtab
   return result;
 }
 
+struct compunit_symtab *
+dwarf2_base_index_functions::find_pc_sect_compunit_symtab
+     (struct objfile *objfile,
+      struct bound_minimal_symbol msymbol,
+      CORE_ADDR pc,
+      struct obj_section *section,
+      int warn_if_readin)
+{
+  if (objfile->flags & OBJF_READNEVER)
+    return nullptr;
+
+  try
+    {
+      return do_find_pc_sect_compunit_symtab (objfile, msymbol, pc,
+					      section, warn_if_readin);
+    }
+  catch (gdb_exception e)
+    {
+      if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED) == 0)
+	exception_print (gdb_stderr, e);
+      else
+	read_full_dwarf_from_debuginfod (objfile, this);
+      return nullptr;
+    }
+}
+
 void
 dwarf2_base_index_functions::map_symbol_filenames
      (struct objfile *objfile,
@@ -3350,6 +3379,29 @@ get_gdb_index_contents_from_cache_dwz (objfile *obj, dwz_file *dwz)
   return global_index_cache.lookup_gdb_index (build_id, &dwz->index_cache_res);
 }
 
+/* Query debuginfod for the .gdb_index matching OBJFILE's build-id.  Return the
+   contents if successful.  */
+
+static gdb::array_view<const gdb_byte>
+get_gdb_index_contents_from_debuginfod (objfile *objfile, dwarf2_per_bfd *per_bfd)
+{
+  const bfd_build_id *build_id = build_id_bfd_get (objfile->obfd.get ());
+  if (build_id == nullptr)
+    return {};
+
+  gdb::unique_xmalloc_ptr<char> index_path;
+  scoped_fd fd = debuginfod_section_query (build_id->data, build_id->size,
+					   bfd_get_filename
+					     (objfile->obfd.get ()),
+					   ".gdb_index",
+					   &index_path);
+  if (fd.get () < 0)
+    return {};
+
+  return global_index_cache.lookup_gdb_index_debuginfod
+    (index_path.get (), &per_bfd->index_cache_res);
+}
+
 static quick_symbol_functions_up make_cooked_index_funcs ();
 
 /* See dwarf2/public.h.  */
@@ -3415,10 +3467,106 @@ dwarf2_initialize_objfile (struct objfile *objfile)
       return;
     }
 
+  if ((objfile->flags & OBJF_DOWNLOAD_DEFERRED)
+      && dwarf2_read_gdb_index (per_objfile,
+				get_gdb_index_contents_from_debuginfod,
+				nullptr))
+    {
+      dwarf_read_debug_printf ("found .gdb_index from debuginfod");
+      objfile->qf.push_front (per_bfd->index_table->make_quick_functions ());
+      return;
+    }
+
   global_index_cache.miss ();
   objfile->qf.push_front (make_cooked_index_funcs ());
 }
 
+/* See read.h.  */
+
+void
+read_full_dwarf_from_debuginfod (struct objfile *objfile,
+				 dwarf2_base_index_functions *fncs)
+{
+  gdb_assert (objfile->flags & OBJF_DOWNLOAD_DEFERRED);
+
+  const struct bfd_build_id *build_id = build_id_bfd_get (objfile->obfd.get ());
+  const char *filename;
+  gdb_bfd_ref_ptr debug_bfd;
+  gdb::unique_xmalloc_ptr<char> symfile_path;
+  scoped_fd fd;
+
+  if (build_id == nullptr)
+    goto unset;
+
+  filename = bfd_get_filename (objfile->obfd.get ());
+  fd = debuginfod_debuginfo_query (build_id->data, build_id->size,
+				   filename, &symfile_path);
+  if (fd.get () < 0)
+    goto unset;
+
+  /* Separate debuginfo successfully retrieved from server.  */
+  debug_bfd = symfile_bfd_open (symfile_path.get ());
+  if (debug_bfd == nullptr
+      || !build_id_verify (debug_bfd.get (), build_id->size, build_id->data))
+    {
+      warning (_("File \"%s\" from debuginfod cannot be opened as bfd"),
+	       filename);
+      goto unset;
+    }
+
+  /* This may also trigger a dwz download.  */
+  symbol_file_add_separate (debug_bfd, symfile_path.get (),
+			    current_inferior ()->symfile_flags, objfile);
+
+  /* Clear frame data so it can be recalculated using DWARF.  */
+  dwarf2_clear_frame_data (objfile);
+
+unset:
+  objfile->flags &= ~OBJF_DOWNLOAD_DEFERRED;
+
+  /* Avoid reading this objfile's index from now on.  If available the
+     separate debug objfile's index will be used instead, since it actually
+     contains the symbols and CUs referenced in the index.  */
+  objfile->remove_partial_symbol (fncs);
+}
+
+/* See public.h.  */
+
+bool
+dwarf2_has_separate_index (struct objfile *objfile)
+{
+  if (objfile->flags & OBJF_DOWNLOAD_DEFERRED)
+    return true;
+  if (objfile->flags & OBJF_MAINLINE)
+    return false;
+  if (!IS_DIR_SEPARATOR (*objfile_filename (objfile)))
+    return false;
+
+  gdb::unique_xmalloc_ptr<char> index_path;
+  const bfd_build_id *build_id = build_id_bfd_get (objfile->obfd.get ());
+
+  if (build_id == nullptr)
+    return false;
+
+  scoped_fd fd = debuginfod_section_query (build_id->data,
+					   build_id->size,
+					   bfd_get_filename
+					     (objfile->obfd.get ()),
+					   ".gdb_index",
+					   &index_path);
+
+  if (fd.get () < 0)
+    return false;
+
+  /* We found a separate .gdb_index file so a separate debuginfo file
+     should exist, but we don't want to download it until necessary.
+     Attach the index to this objfile and defer the debuginfo download
+     until gdb needs to expand symtabs referenced by the index.  */
+  objfile->flags |= OBJF_DOWNLOAD_DEFERRED;
+  dwarf2_initialize_objfile (objfile);
+  return true;
+}
+
 
 
 /* Build a partial symbol table.  */
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index 37023a20709..e3131693b81 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -866,6 +866,10 @@ struct dwarf2_base_index_functions : public quick_symbol_functions
      CORE_ADDR pc, struct obj_section *section, int warn_if_readin)
        override final;
 
+  struct compunit_symtab *do_find_pc_sect_compunit_symtab
+    (struct objfile *objfile, struct bound_minimal_symbol msymbol,
+     CORE_ADDR pc, struct obj_section *section, int warn_if_readin);
+
   struct compunit_symtab *find_compunit_symtab_by_address
     (struct objfile *objfile, CORE_ADDR address) override
   {
@@ -942,4 +946,10 @@ extern bool read_addrmap_from_aranges (dwarf2_per_objfile *per_objfile,
 				       dwarf2_section_info *section,
 				       addrmap *mutable_map);
 
+/* If OBJFILE contains information from a separately downloaded .gdb_index,
+   attempt to download the full debuginfo.  */
+
+extern void read_full_dwarf_from_debuginfod (struct objfile *,
+					     dwarf2_base_index_functions *);
+
 #endif /* DWARF2READ_H */
diff --git a/gdb/dwarf2/section.c b/gdb/dwarf2/section.c
index c9ef41893ee..8cb09e3381a 100644
--- a/gdb/dwarf2/section.c
+++ b/gdb/dwarf2/section.c
@@ -54,7 +54,8 @@ dwarf2_section_info::get_bfd_owner () const
       section = get_containing_section ();
       gdb_assert (!section->is_virtual);
     }
-  gdb_assert (section->s.section != nullptr);
+  if (section->s.section == nullptr)
+    error (_("Can't find owner of DWARF section."));
   return section->s.section->owner;
 }
 
diff --git a/gdb/elfread.c b/gdb/elfread.c
index 0305bf21894..01eccfaac36 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -1239,7 +1239,7 @@ elf_symfile_read_dwarf2 (struct objfile *objfile,
 	    symbol_file_add_separate (debug_bfd, debugfile.c_str (),
 				      symfile_flags, objfile);
 	}
-      else
+      else if (!dwarf2_has_separate_index (objfile))
 	{
 	  has_dwarf2 = false;
 	  const struct bfd_build_id *build_id
diff --git a/gdb/objfile-flags.h b/gdb/objfile-flags.h
index 9dee2ee51a0..fb3f741c899 100644
--- a/gdb/objfile-flags.h
+++ b/gdb/objfile-flags.h
@@ -60,6 +60,10 @@ enum objfile_flag : unsigned
     /* User requested that we do not read this objfile's symbolic
        information.  */
     OBJF_READNEVER = 1 << 6,
+
+    /* A separate .gdb_index has been downloaded for this objfile.
+       Debuginfo for this objfile can be downloaded when required.  */
+    OBJF_DOWNLOAD_DEFERRED = 1 << 7,
   };
 
 DEF_ENUM_FLAGS_TYPE (enum objfile_flag, objfile_flags);
diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index 9caebfefd59..7f32037caa5 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -52,6 +52,7 @@
 #include "gdb_bfd.h"
 #include "btrace.h"
 #include "gdbsupport/pathstuff.h"
+#include "symfile.h"
 
 #include <algorithm>
 #include <vector>
diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index 342aa09ac6a..d00c2b21933 100644
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -587,6 +587,17 @@ struct objfile
   /* See quick_symbol_functions.  */
   void require_partial_symbols (bool verbose);
 
+  /* Remove TARGET from this objfile's collection of quick_symbol_functions.  */
+  void remove_partial_symbol (quick_symbol_functions *target)
+  {
+    for (quick_symbol_functions_up &qf_up : qf)
+      if (qf_up.get () == target)
+	{
+	  qf.remove (qf_up);
+	  return;
+	}
+  }
+
   /* Return the relocation offset applied to SECTION.  */
   CORE_ADDR section_offset (bfd_section *section) const
   {
@@ -611,13 +622,20 @@ struct objfile
 
 private:
 
+  using qf_list = std::forward_list<quick_symbol_functions_up>;
+  using unwrapping_qf_range = iterator_range<unwrapping_iterator<qf_list::iterator>>;
+  using qf_safe_range = basic_safe_range<unwrapping_qf_range>;
+
   /* Ensure that partial symbols have been read and return the "quick" (aka
      partial) symbol functions for this symbol reader.  */
-  const std::forward_list<quick_symbol_functions_up> &
+  qf_safe_range
   qf_require_partial_symbols ()
   {
     this->require_partial_symbols (true);
-    return qf;
+    return qf_safe_range
+      (unwrapping_qf_range
+	(unwrapping_iterator<qf_list::iterator> (qf.begin ()),
+	 unwrapping_iterator<qf_list::iterator> (qf.end ())));
   }
 
 public:
diff --git a/gdb/progspace.c b/gdb/progspace.c
index 32bdfebcf7c..1ed75eef2f9 100644
--- a/gdb/progspace.c
+++ b/gdb/progspace.c
@@ -139,19 +139,19 @@ program_space::free_all_objfiles ()
 
 void
 program_space::add_objfile (std::unique_ptr<objfile> &&objfile,
-			    struct objfile *before)
+			    struct objfile *after)
 {
-  if (before == nullptr)
+  if (after == nullptr)
     objfiles_list.push_back (std::move (objfile));
   else
     {
       auto iter = std::find_if (objfiles_list.begin (), objfiles_list.end (),
 				[=] (const std::unique_ptr<::objfile> &objf)
 				{
-				  return objf.get () == before;
+				  return objf.get () == after;
 				});
       gdb_assert (iter != objfiles_list.end ());
-      objfiles_list.insert (iter, std::move (objfile));
+      objfiles_list.insert (++iter, std::move (objfile));
     }
 }
 
diff --git a/gdb/progspace.h b/gdb/progspace.h
index 85215f0e2f1..933474ca8af 100644
--- a/gdb/progspace.h
+++ b/gdb/progspace.h
@@ -40,56 +40,141 @@ struct address_space;
 struct program_space;
 struct so_list;
 
+/* An iterator that wraps an iterator over std::unique_ptr, and dereferences
+   the returned object.  This is useful for iterating over a list of shared
+   pointers and returning raw pointers -- which helped avoid touching a lot
+   of code when changing how objfiles are managed.  */
+
+template<typename UniquePtrIter>
+class unwrapping_iterator
+{
+public:
+  typedef unwrapping_iterator self_type;
+  typedef typename UniquePtrIter::value_type::pointer value_type;
+  typedef typename UniquePtrIter::reference  reference;
+  typedef typename UniquePtrIter::pointer pointer;
+  typedef typename UniquePtrIter::iterator_category iterator_category;
+  typedef typename UniquePtrIter::difference_type difference_type;
+
+  unwrapping_iterator (UniquePtrIter iter)
+    : m_iter (std::move (iter))
+  {
+  }
+
+  value_type operator* () const
+  {
+    return m_iter->get ();
+  }
+
+  unwrapping_iterator operator++ ()
+  {
+    ++m_iter;
+    return *this;
+  }
+
+  bool operator!= (const unwrapping_iterator &other) const
+  {
+    return m_iter != other.m_iter;
+  }
+
+private:
+  /* The underlying iterator.  */
+  UniquePtrIter m_iter;
+};
+
 typedef std::list<std::unique_ptr<objfile>> objfile_list;
 
-/* An iterator that wraps an iterator over std::unique_ptr<objfile>,
-   and dereferences the returned object.  This is useful for iterating
-   over a list of shared pointers and returning raw pointers -- which
-   helped avoid touching a lot of code when changing how objfiles are
-   managed.  */
+/* An reverse iterator that wraps an iterator over objfile_list, and
+   dereferences the returned object.  This is useful for reverse iterating
+   over a list of shared pointers and returning raw pointers -- which helped
+   avoid touching a lot of code when changing how objfiles are managed.  */
 
-class unwrapping_objfile_iterator
+class unwrapping_reverse_objfile_iterator
 {
 public:
-
-  typedef unwrapping_objfile_iterator self_type;
+  typedef unwrapping_reverse_objfile_iterator self_type;
   typedef typename ::objfile *value_type;
   typedef typename ::objfile &reference;
   typedef typename ::objfile **pointer;
   typedef typename objfile_list::iterator::iterator_category iterator_category;
   typedef typename objfile_list::iterator::difference_type difference_type;
 
-  unwrapping_objfile_iterator (objfile_list::iterator iter)
-    : m_iter (std::move (iter))
-  {
-  }
-
-  objfile *operator* () const
+  value_type operator* () const
   {
     return m_iter->get ();
   }
 
-  unwrapping_objfile_iterator operator++ ()
+  unwrapping_reverse_objfile_iterator operator++ ()
   {
-    ++m_iter;
+    if (m_iter != m_begin)
+      --m_iter;
+    else
+      {
+	/* We can't decrement M_ITER since it is the begin iterator of the
+	   objfile list.  Set M_ITER to the list's end iterator to indicate
+	   this is now one-past-the-end.  */
+	m_iter = m_end;
+
+	/* Overwrite M_BEGIN to avoid possibly copying an invalid iterator.  */
+	m_begin = m_end;
+      }
+
     return *this;
   }
 
-  bool operator!= (const unwrapping_objfile_iterator &other) const
+  bool operator!= (const unwrapping_reverse_objfile_iterator &other) const
   {
     return m_iter != other.m_iter;
   }
 
+  /* Return an unwrapping reverse iterator starting at the last element of
+     OBJF_LIST.  */
+  static unwrapping_reverse_objfile_iterator begin (objfile_list &objf_list)
+  {
+    auto begin = objf_list.begin ();
+    auto end = objf_list.end ();
+    auto rev_begin = objf_list.end ();
+
+    /* Start REV_BEGIN on the last objfile in OBJF_LIST.  */
+    if (begin != end)
+      --rev_begin;
+
+    return unwrapping_reverse_objfile_iterator (rev_begin, begin, end);
+  }
+
+  /* Return a one-past-the-end unwrapping reverse iterator.  */
+  static unwrapping_reverse_objfile_iterator end (objfile_list &objf_list)
+  {
+    return unwrapping_reverse_objfile_iterator (objf_list.end (),
+						objf_list.end (),
+						objf_list.end ());
+  }
+
 private:
+  /* This begin and end methods should be used to create these objects.  */
+  unwrapping_reverse_objfile_iterator (objfile_list::iterator iter,
+				       objfile_list::iterator begin,
+				       objfile_list::iterator end)
+    : m_iter (std::move (iter)), m_begin (std::move (begin)),
+      m_end (std::move (end))
+  {
+  }
 
-  /* The underlying iterator.  */
-  objfile_list::iterator m_iter;
-};
+ /* The underlying iterator.  */
+ objfile_list::iterator m_iter;
 
+ /* The underlying iterator pointing to the first objfile in the sequence.  Used
+    to track when to stop decrementing M_ITER.  */
+ objfile_list::iterator m_begin;
 
-/* A range that returns unwrapping_objfile_iterators.  */
+  /* The underlying iterator's one-past-the-end.  */
+ objfile_list::iterator m_end;
+};
 
-using unwrapping_objfile_range = iterator_range<unwrapping_objfile_iterator>;
+/* A range that returns unwrapping_iterators.  */
+
+using unwrapping_objfile_range
+  = iterator_range<unwrapping_iterator<objfile_list::iterator>>;
 
 /* A program space represents a symbolic view of an address space.
    Roughly speaking, it holds all the data associated with a
@@ -209,11 +294,12 @@ struct program_space
   objfiles_range objfiles ()
   {
     return objfiles_range
-      (unwrapping_objfile_iterator (objfiles_list.begin ()),
-       unwrapping_objfile_iterator (objfiles_list.end ()));
+      (unwrapping_iterator<objfile_list::iterator> (objfiles_list.begin ()),
+       unwrapping_iterator<objfile_list::iterator> (objfiles_list.end ()));
   }
 
-  using objfiles_safe_range = basic_safe_range<objfiles_range>;
+  using objfiles_reverse_range = iterator_range<unwrapping_reverse_objfile_iterator>;
+  using objfiles_safe_reverse_range = basic_safe_range<objfiles_reverse_range>;
 
   /* An iterable object that can be used to iterate over all objfiles.
      The basic use is in a foreach, like:
@@ -221,20 +307,25 @@ struct program_space
      for (objfile *objf : pspace->objfiles_safe ()) { ... }
 
      This variant uses a basic_safe_iterator so that objfiles can be
-     deleted during iteration.  */
-  objfiles_safe_range objfiles_safe ()
+     deleted during iteration.
+
+     The use of a reverse iterator helps ensure that separate debug
+     objfiles are deleted before their parent objfile.  This prevents
+     the invalidation of an iterator due to the deletion of a parent
+     objfile.  */
+  objfiles_safe_reverse_range objfiles_safe ()
   {
-    return objfiles_safe_range
-      (objfiles_range
-	 (unwrapping_objfile_iterator (objfiles_list.begin ()),
-	  unwrapping_objfile_iterator (objfiles_list.end ())));
+    return objfiles_safe_reverse_range
+      (objfiles_reverse_range
+	(unwrapping_reverse_objfile_iterator::begin (objfiles_list),
+	 unwrapping_reverse_objfile_iterator::end (objfiles_list)));
   }
 
-  /* Add OBJFILE to the list of objfiles, putting it just before
-     BEFORE.  If BEFORE is nullptr, it will go at the end of the
+  /* Add OBJFILE to the list of objfiles, putting it just after
+     AFTER.  If AFTER is nullptr, it will go at the end of the
      list.  */
   void add_objfile (std::unique_ptr<objfile> &&objfile,
-		    struct objfile *before);
+		    struct objfile *after);
 
   /* Remove OBJFILE from the list of objfiles.  */
   void remove_objfile (struct objfile *objfile);
diff --git a/gdb/symfile-debug.c b/gdb/symfile-debug.c
index 9db5c47a8ce..784b81b5ca6 100644
--- a/gdb/symfile-debug.c
+++ b/gdb/symfile-debug.c
@@ -109,9 +109,9 @@ objfile::has_unexpanded_symtabs ()
 		objfile_debug_name (this));
 
   bool result = false;
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      if (iter->has_unexpanded_symtabs (this))
+      if (qf->has_unexpanded_symtabs (this))
 	{
 	  result = true;
 	  break;
@@ -134,9 +134,9 @@ objfile::find_last_source_symtab ()
     gdb_printf (gdb_stdlog, "qf->find_last_source_symtab (%s)\n",
 		objfile_debug_name (this));
 
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      retval = iter->find_last_source_symtab (this);
+      retval = qf->find_last_source_symtab (this);
       if (retval != nullptr)
 	break;
     }
@@ -167,8 +167,8 @@ objfile::forget_cached_source_info ()
 	}
     }
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->forget_cached_source_info (this);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->forget_cached_source_info (this);
 }
 
 bool
@@ -214,17 +214,17 @@ objfile::map_symtabs_matching_filename
     return result;
   };
 
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      if (!iter->expand_symtabs_matching (this,
-					  match_one_filename,
-					  nullptr,
-					  nullptr,
-					  on_expansion,
-					  (SEARCH_GLOBAL_BLOCK
-					   | SEARCH_STATIC_BLOCK),
-					  UNDEF_DOMAIN,
-					  ALL_DOMAIN))
+      if (!qf->expand_symtabs_matching (this,
+					match_one_filename,
+					nullptr,
+					nullptr,
+					on_expansion,
+					(SEARCH_GLOBAL_BLOCK
+					 | SEARCH_STATIC_BLOCK),
+					UNDEF_DOMAIN,
+					ALL_DOMAIN))
 	{
 	  retval = false;
 	  break;
@@ -283,18 +283,18 @@ objfile::lookup_symbol (block_enum kind, const char *name, domain_enum domain)
     return true;
   };
 
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      if (!iter->expand_symtabs_matching (this,
-					  nullptr,
-					  &lookup_name,
-					  nullptr,
-					  search_one_symtab,
-					  kind == GLOBAL_BLOCK
-					  ? SEARCH_GLOBAL_BLOCK
-					  : SEARCH_STATIC_BLOCK,
-					  domain,
-					  ALL_DOMAIN))
+      if (!qf->expand_symtabs_matching (this,
+					nullptr,
+					&lookup_name,
+					nullptr,
+					search_one_symtab,
+					kind == GLOBAL_BLOCK
+					? SEARCH_GLOBAL_BLOCK
+					: SEARCH_STATIC_BLOCK,
+					domain,
+					ALL_DOMAIN))
 	break;
     }
 
@@ -314,8 +314,8 @@ objfile::print_stats (bool print_bcache)
     gdb_printf (gdb_stdlog, "qf->print_stats (%s, %d)\n",
 		objfile_debug_name (this), print_bcache);
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->print_stats (this, print_bcache);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->print_stats (this, print_bcache);
 }
 
 void
@@ -340,16 +340,16 @@ objfile::expand_symtabs_for_function (const char *func_name)
   lookup_name_info base_lookup (func_name, symbol_name_match_type::FULL);
   lookup_name_info lookup_name = base_lookup.make_ignore_params ();
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->expand_symtabs_matching (this,
-				   nullptr,
-				   &lookup_name,
-				   nullptr,
-				   nullptr,
-				   (SEARCH_GLOBAL_BLOCK
-				    | SEARCH_STATIC_BLOCK),
-				   VAR_DOMAIN,
-				   ALL_DOMAIN);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->expand_symtabs_matching (this,
+				 nullptr,
+				 &lookup_name,
+				 nullptr,
+				 nullptr,
+				 (SEARCH_GLOBAL_BLOCK
+				  | SEARCH_STATIC_BLOCK),
+				 VAR_DOMAIN,
+				 ALL_DOMAIN);
 }
 
 void
@@ -359,8 +359,8 @@ objfile::expand_all_symtabs ()
     gdb_printf (gdb_stdlog, "qf->expand_all_symtabs (%s)\n",
 		objfile_debug_name (this));
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->expand_all_symtabs (this);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->expand_all_symtabs (this);
 }
 
 void
@@ -377,16 +377,16 @@ objfile::expand_symtabs_with_fullname (const char *fullname)
     return filename_cmp (basenames ? basename : fullname, filename) == 0;
   };
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->expand_symtabs_matching (this,
-				   file_matcher,
-				   nullptr,
-				   nullptr,
-				   nullptr,
-				   (SEARCH_GLOBAL_BLOCK
-				    | SEARCH_STATIC_BLOCK),
-				   UNDEF_DOMAIN,
-				   ALL_DOMAIN);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->expand_symtabs_matching (this,
+				 file_matcher,
+				 nullptr,
+				 nullptr,
+				 nullptr,
+				 (SEARCH_GLOBAL_BLOCK
+				  | SEARCH_STATIC_BLOCK),
+				 UNDEF_DOMAIN,
+				 ALL_DOMAIN);
 }
 
 void
@@ -402,9 +402,9 @@ objfile::expand_matching_symbols
 		domain_name (domain), global,
 		host_address_to_string (ordered_compare));
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->expand_matching_symbols (this, name, domain, global,
-				   ordered_compare);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->expand_matching_symbols (this, name, domain, global,
+				 ordered_compare);
 }
 
 bool
@@ -429,10 +429,10 @@ objfile::expand_symtabs_matching
 		host_address_to_string (&expansion_notify),
 		search_domain_name (kind));
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    if (!iter->expand_symtabs_matching (this, file_matcher, lookup_name,
-					symbol_matcher, expansion_notify,
-					search_flags, domain, kind))
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    if (!qf->expand_symtabs_matching (this, file_matcher, lookup_name,
+				      symbol_matcher, expansion_notify,
+				      search_flags, domain, kind))
       return false;
   return true;
 }
@@ -454,10 +454,10 @@ objfile::find_pc_sect_compunit_symtab (struct bound_minimal_symbol msymbol,
 		host_address_to_string (section),
 		warn_if_readin);
 
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      retval = iter->find_pc_sect_compunit_symtab (this, msymbol, pc, section,
-						   warn_if_readin);
+      retval = qf->find_pc_sect_compunit_symtab (this, msymbol, pc, section,
+						 warn_if_readin);
       if (retval != nullptr)
 	break;
     }
@@ -482,8 +482,8 @@ objfile::map_symbol_filenames (gdb::function_view<symbol_filename_ftype> fun,
 		objfile_debug_name (this),
 		need_fullname);
 
-  for (const auto &iter : qf_require_partial_symbols ())
-    iter->map_symbol_filenames (this, fun, need_fullname);
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
+    qf->map_symbol_filenames (this, fun, need_fullname);
 }
 
 struct compunit_symtab *
@@ -496,9 +496,9 @@ objfile::find_compunit_symtab_by_address (CORE_ADDR address)
 		hex_string (address));
 
   struct compunit_symtab *result = NULL;
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      result = iter->find_compunit_symtab_by_address (this, address);
+      result = qf->find_compunit_symtab_by_address (this, address);
       if (result != nullptr)
 	break;
     }
@@ -521,10 +521,10 @@ objfile::lookup_global_symbol_language (const char *name,
   enum language result = language_unknown;
   *symbol_found_p = false;
 
-  for (const auto &iter : qf_require_partial_symbols ())
+  for (quick_symbol_functions *qf : qf_require_partial_symbols ())
     {
-      result = iter->lookup_global_symbol_language (this, name, domain,
-						    symbol_found_p);
+      result = qf->lookup_global_symbol_language (this, name, domain,
+						  symbol_found_p);
       if (*symbol_found_p)
 	break;
     }
diff --git a/gdb/symfile.c b/gdb/symfile.c
index 8ae2177b159..9c943c4d5be 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -992,6 +992,10 @@ syms_from_objfile (struct objfile *objfile,
 static void
 finish_new_objfile (struct objfile *objfile, symfile_add_flags add_flags)
 {
+  struct objfile *parent = objfile->separate_debug_objfile_backlink;
+  bool was_deferred
+    = (parent != nullptr) && (parent->flags & OBJF_DOWNLOAD_DEFERRED);
+
   /* If this is the main symbol file we have to clean up all users of the
      old main symbol file.  Otherwise it is sufficient to fixup all the
      breakpoints that may have been redefined by this symbol file.  */
@@ -1002,7 +1006,8 @@ finish_new_objfile (struct objfile *objfile, symfile_add_flags add_flags)
 
       clear_symtab_users (add_flags);
     }
-  else if ((add_flags & SYMFILE_DEFER_BP_RESET) == 0)
+  else if ((add_flags & SYMFILE_DEFER_BP_RESET) == 0
+	   && !was_deferred)
     {
       breakpoint_re_set ();
     }
diff --git a/gdb/testsuite/gdb.python/py-objfile.exp b/gdb/testsuite/gdb.python/py-objfile.exp
index 61b9942de79..0bf49976b73 100644
--- a/gdb/testsuite/gdb.python/py-objfile.exp
+++ b/gdb/testsuite/gdb.python/py-objfile.exp
@@ -135,7 +135,7 @@ gdb_test "p main" "= {<text variable, no debug info>} $hex <main>" \
 gdb_py_test_silent_cmd "python objfile.add_separate_debug_file(\"${binfile}\")" \
     "Add separate debug file file" 1
 
-gdb_py_test_silent_cmd "python sep_objfile = gdb.objfiles()\[0\]" \
+gdb_py_test_silent_cmd "python sep_objfile = gdb.objfiles()\[1\]" \
     "Get separate debug info objfile" 1
 
 gdb_test "python print (sep_objfile.owner.filename)" "${testfile}2" \
