[PATCH] Cache the BFD file size for readonly input

["H.J. Lu" <hjl dot tools at gmail dot com>]

bfd_get_file_size may be called many times on the same input file with
many sections.  Cache the file size to avoid calling stat repeatedly
for non-archive members.

OK for master?

H.J.
---
	PR ld/21679
	* bfd.c (bfd): Add file_size_set and file_size.
	* bfd-in2.h: Regenerated.
	* bfdio.c (bfd_get_file_size): Cache the file size for readonly
	input.
---
 bfd/bfd-in2.h |  7 +++++++
 bfd/bfd.c     |  7 +++++++
 bfd/bfdio.c   | 14 +++++++++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index 8c312e3..2141bcb 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -6866,6 +6866,10 @@ struct bfd
      getting it from the file each time.  */
   unsigned int mtime_set : 1;
 
+  /* Set if we have a cached file size, rather than getting it from the
+     file each time.  */
+  unsigned int file_size_set : 1;
+
   /* Flag set if symbols from this BFD should not be exported.  */
   unsigned int no_export : 1;
 
@@ -6927,6 +6931,9 @@ struct bfd
      be used only for archive elements.  */
   int archive_pass;
 
+  /* The file size.  */
+  ufile_ptr file_size;
+
   /* Stuff only useful for object files:
      The start address.  */
   bfd_vma start_address;
diff --git a/bfd/bfd.c b/bfd/bfd.c
index c6fce45..946d0bc 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -206,6 +206,10 @@ CODE_FRAGMENT
 .     getting it from the file each time.  *}
 .  unsigned int mtime_set : 1;
 .
+.  {* Set if we have a cached file size, rather than getting it from the
+.     file each time.  *}
+.  unsigned int file_size_set : 1;
+.
 .  {* Flag set if symbols from this BFD should not be exported.  *}
 .  unsigned int no_export : 1;
 .
@@ -267,6 +271,9 @@ CODE_FRAGMENT
 .     be used only for archive elements.  *}
 .  int archive_pass;
 .
+.  {* The file size.  *}
+.  ufile_ptr file_size;
+.
 .  {* Stuff only useful for object files:
 .     The start address.  *}
 .  bfd_vma start_address;
diff --git a/bfd/bfdio.c b/bfd/bfdio.c
index e301570..51203e5 100644
--- a/bfd/bfdio.c
+++ b/bfd/bfdio.c
@@ -451,11 +451,23 @@ DESCRIPTION
 file_ptr
 bfd_get_file_size (bfd *abfd)
 {
+  ufile_ptr file_size;
+
+  if (abfd->file_size_set)
+    return abfd->file_size;
+
   if (abfd->my_archive != NULL
       && !bfd_is_thin_archive (abfd->my_archive))
     return arelt_size (abfd);
 
-  return bfd_get_size (abfd);
+  file_size = bfd_get_size (abfd);
+  if (abfd->direction == read_direction)
+    {
+      abfd->file_size = file_size;
+      abfd->file_size_set = TRUE;
+    }
+
+  return file_size;
 }
 
 /*
-- 
2.9.4