pe_ILF_object_p and bfd_check_format_matches

If pe_ILF_object_p succeeds, pe_ILF_build_a_bfd will have changed the
bfd from being file backed to in-memory.  This can have unfortunate
results for targets checked by bfd_check_format_matches after that
point as they will be matching against the created in-memory image
rather than the file.  bfd_preserve_restore also has a problem if it
flips the BFD_IN_MEMORY flag, because the flag affects iostream
meaning and should be set if using _bfd_memory_iovec.  To fix these
problems, save and restore iostream and iovec along with flags, and
modify bfd_reinit to make the bfd file backed again.  Restoring the
iovec and iostream allows the hack in bfd_reinit keeping BFD_IN_MEMORY
(part of BFD_FLAGS_SAVED) to be removed.
One more detail: If restoring from file backed to in-memory then the
bfd needs to be forcibly removed from the cache lru list, since after
the bfd becomes in-memory a bfd_close will delete the bfd's memory
leaving the lru list pointing into freed memory.

	* cache.c (bfd_cache_init): Clear BFD_CLOSED_BY_CACHE here..
	(bfd_cache_lookup_worker): ..rather than here.
	(bfd_cache_close): Comment.
	* format.c (struct bfd_preserve): Add iovec and iostream fields.
	(bfd_preserve_save): Save them..
	(bfd_preserve_restore): ..and restore them, calling
	bfd_cache_close if the iovec differs.
	(bfd_reinit): Add preserve param.  If the bfd has been flipped
	to in-memory, reopen the file.  Restore flags.
	* peicode.h (pe_ILF_cleanup): New function.
	(pe_ILF_object_p): Return it.
	* bfd.c (BFD_FLAGS_SAVED): Delete.
	* bfd-in2.h: Regenerate.

bfd/bfd-in2.h

@@ -6622,12 +6622,6 @@ struct bfd
   /* Compress sections in this BFD with SHF_COMPRESSED zstd.  */
 #define BFD_COMPRESS_ZSTD      0x400000
 
-  /* Flags bits to be saved in bfd_preserve_save.  */
-#define BFD_FLAGS_SAVED \
-  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
-   | BFD_PLUGIN | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON \
-   | BFD_USE_ELF_STT_COMMON | BFD_COMPRESS_ZSTD)
-
   /* Flags bits which are for BFD use only.  */
 #define BFD_FLAGS_FOR_BFD_USE_MASK \
   (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \

bfd/bfd.c

@@ -181,12 +181,6 @@ CODE_FRAGMENT
 .  {* Compress sections in this BFD with SHF_COMPRESSED zstd.  *}
 .#define BFD_COMPRESS_ZSTD      0x400000
 .
-.  {* Flags bits to be saved in bfd_preserve_save.  *}
-.#define BFD_FLAGS_SAVED \
-.  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
-.   | BFD_PLUGIN | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON \
-.   | BFD_USE_ELF_STT_COMMON | BFD_COMPRESS_ZSTD)
-.
 .  {* Flags bits which are for BFD use only.  *}
 .#define BFD_FLAGS_FOR_BFD_USE_MASK \
 .  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \

bfd/cache.c

@@ -266,10 +266,7 @@ bfd_cache_lookup_worker (bfd *abfd, enum cache_flag flag)
 	   && !(flag & CACHE_NO_SEEK_ERROR))
     bfd_set_error (bfd_error_system_call);
   else
-    {
-      abfd->flags &= ~BFD_CLOSED_BY_CACHE;
-      return (FILE *) abfd->iostream;
-    }
+    return (FILE *) abfd->iostream;
 
   /* xgettext:c-format */
   _bfd_error_handler (_("reopening %pB: %s"),
@@ -506,6 +503,7 @@ bfd_cache_init (bfd *abfd)
     }
   abfd->iovec = &cache_iovec;
   insert (abfd);
+  abfd->flags &= ~BFD_CLOSED_BY_CACHE;
   ++open_files;
   return true;
 }
@@ -528,6 +526,7 @@ DESCRIPTION
 bool
 bfd_cache_close (bfd *abfd)
 {
+  /* Don't remove this test.  bfd_reinit depends on it.  */
   if (abfd->iovec != &cache_iovec)
     return true;
 

bfd/format.c

@@ -99,6 +99,8 @@ struct bfd_preserve
   void *marker;
   void *tdata;
   flagword flags;
+  const struct bfd_iovec *iovec;
+  void *iostream;
   const struct bfd_arch_info *arch_info;
   struct bfd_section *sections;
   struct bfd_section *section_last;
@@ -125,6 +127,8 @@ bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve,
   preserve->tdata = abfd->tdata.any;
   preserve->arch_info = abfd->arch_info;
   preserve->flags = abfd->flags;
+  preserve->iovec = abfd->iovec;
+  preserve->iostream = abfd->iostream;
   preserve->sections = abfd->sections;
   preserve->section_last = abfd->section_last;
   preserve->section_count = abfd->section_count;
@@ -143,14 +147,24 @@ bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve,
 /* Clear out a subset of BFD state.  */
 
 static void
-bfd_reinit (bfd *abfd, unsigned int section_id, bfd_cleanup cleanup)
+bfd_reinit (bfd *abfd, unsigned int section_id,
+	    struct bfd_preserve *preserve, bfd_cleanup cleanup)
 {
   _bfd_section_id = section_id;
   if (cleanup)
     cleanup (abfd);
   abfd->tdata.any = NULL;
   abfd->arch_info = &bfd_default_arch_struct;
-  abfd->flags &= BFD_FLAGS_SAVED;
+  if ((abfd->flags & BFD_CLOSED_BY_CACHE) != 0
+      && (abfd->flags & BFD_IN_MEMORY) != 0
+      && (preserve->flags & BFD_CLOSED_BY_CACHE) == 0
+      && (preserve->flags & BFD_IN_MEMORY) == 0)
+    {
+      /* This is to reverse pe_ILF_build_a_bfd, which closes the file
+	 and sets up a bfd in memory.  */
+      bfd_open_file (abfd);
+    }
+  abfd->flags = preserve->flags;
   abfd->build_id = NULL;
   bfd_section_list_clear (abfd);
 }
@@ -164,7 +178,11 @@ bfd_preserve_restore (bfd *abfd, struct bfd_preserve *preserve)
 
   abfd->tdata.any = preserve->tdata;
   abfd->arch_info = preserve->arch_info;
+  if (abfd->iovec != preserve->iovec)
+    bfd_cache_close (abfd);
   abfd->flags = preserve->flags;
+  abfd->iovec = preserve->iovec;
+  abfd->iostream = preserve->iostream;
   abfd->section_htab = preserve->section_htab;
   abfd->sections = preserve->sections;
   abfd->section_last = preserve->section_last;
@@ -368,7 +386,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
       /* If we already tried a match, the bfd is modified and may
 	 have sections attached, which will confuse the next
 	 _bfd_check_format call.  */
-      bfd_reinit (abfd, initial_section_id, cleanup);
+      bfd_reinit (abfd, initial_section_id, &preserve, cleanup);
       /* Free bfd_alloc memory too.  If we have matched and preserved
 	 a target then the high water mark is that much higher.  */
       if (preserve_match.marker)
@@ -527,7 +545,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
 	 RIGHT_TARG again.  */
       if (match_targ != right_targ)
 	{
-	  bfd_reinit (abfd, initial_section_id, cleanup);
+	  bfd_reinit (abfd, initial_section_id, &preserve, cleanup);
 	  bfd_release (abfd, preserve.marker);
 	  if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
 	    goto err_ret;

bfd/peicode.h

@@ -1158,6 +1158,17 @@ pe_ILF_build_a_bfd (bfd *	    abfd,
   return false;
 }
 
+/* Cleanup function, returned from check_format hook.  */
+
+static void
+pe_ILF_cleanup (bfd *abfd)
+{
+  struct bfd_in_memory *bim = abfd->iostream;
+  free (bim->buffer);
+  free (bim);
+  abfd->iostream = NULL;
+}
+
 /* We have detected an Import Library Format archive element.
    Decode the element and return the appropriate target.  */
 
@@ -1331,7 +1342,7 @@ pe_ILF_object_p (bfd * abfd)
       return NULL;
     }
 
-  return _bfd_no_cleanup;
+  return pe_ILF_cleanup;
 }
 
 static void