Check return value of bfd_init

Alan recently added a way for BFD library users to check whether they
were in fact loading a compatible version of BFD:

https://sourceware.org/ml/binutils/2018-10/msg00198.html

It seemed reasonable to me that gdb should do this check as well, in
case someone is dynamically linking against BFD.

Simon pointed out that an earlier version of the patch would cause a
gdb crash if the test failed.  This version works around this by
lowering the call to bfd_init and adding a comment explaining where
'error' can safely be called in captured_main_1.

gdb/ChangeLog
2018-10-30  Tom Tromey  <tom@tromey.com>

	* main.c (captured_main_1): Check return value of bfd_init.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0207bec..940300f 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2018-10-30  Tom Tromey  <tom@tromey.com>
+
+       * main.c (captured_main_1): Check return value of bfd_init.
+
 2018-10-29  Sergio Durigan Junior  <sergiodj@redhat.com>
 
        * common/offset-type.h (DEFINE_OFFSET_REL_OP): Delete.

diff --git a/gdb/main.c b/gdb/main.c
index 8709357..c71d5b5 100644 (file)
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -506,7 +506,6 @@ captured_main_1 (struct captured_main_args *context)
   textdomain (PACKAGE);
 #endif
 
-  bfd_init ();
   notice_open_fds ();
 
   saved_command_line = (char *) xstrdup ("");
@@ -517,12 +516,17 @@ captured_main_1 (struct captured_main_args *context)
   setvbuf (stderr, NULL, _IONBF, BUFSIZ);
 #endif
 
+  /* Note: `error' cannot be called before this point, because the
+     caller will crash when trying to print the exception.  */
   main_ui = new ui (stdin, stdout, stderr);
   current_ui = main_ui;
 
   gdb_stdtargerr = gdb_stderr; /* for moment */
   gdb_stdtargin = gdb_stdin;   /* for moment */
 
+  if (bfd_init () != BFD_INIT_MAGIC)
+    error (_("fatal error: libbfd ABI mismatch"));
+
 #ifdef __MINGW32__
   /* On Windows, argv[0] is not necessarily set to absolute form when
      GDB is found along PATH, without which relocation doesn't work.  */