[binutils-gdb] gdb: remove final user of the executable_changed observer

[Andrew Burgess]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a2827364e2bf19910fa5a54364a594a5ba3033b8

commit a2827364e2bf19910fa5a54364a594a5ba3033b8
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Fri Sep 8 15:48:16 2023 +0100

    gdb: remove final user of the executable_changed observer
    
    This commit continues with the task started in the previous commit,
    and is similar in many ways.
    
    The goal of the next couple of commits is to expose the
    executable_changed observable in the Python API as an event.  Before I
    do this I would like to remove the additional call to the
    executable_changed observable which can be found in the reread_symbols
    function in the symfile.c file, as I don't believe that this use
    actually corresponds to a change in the current executable.
    
    The previous commit removed one user of the executable_changed
    observable and replaced it with a new_obfile observer instead, and
    this commit does the same thing.
    
    In auxv.c we use the executable_changed observable to call
    invalidate_auxv_cache, which then calls:
    
      invalidate_auxv_cache_inf (current_inferior ());
    
    The auxv cache is already (additionally) cleared when an inferior
    exits and when an inferior appears.
    
    As with the previous commit, I think we can safely replace the use of
    the executable_changed observable with a use of the new_obfile
    observable.  All the tests still pass, and with some locally placed
    printf calls, I think that the cache is still being cleared in all the
    cases that should matter.
    
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/auxv.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/gdb/auxv.c b/gdb/auxv.c
index 3c27c1f1ffe..9f599b04a4f 100644
--- a/gdb/auxv.c
+++ b/gdb/auxv.c
@@ -344,12 +344,14 @@ invalidate_auxv_cache_inf (struct inferior *inf)
   auxv_inferior_data.clear (inf);
 }
 
-/* Invalidate current inferior's auxv cache.  */
+/* Invalidate current inferior's auxv cache when all symbol table data is
+   cleared (indicated by OBJFILE being nullptr).  */
 
 static void
-invalidate_auxv_cache (void)
+auxv_new_objfile_observer (struct objfile *objfile)
 {
-  invalidate_auxv_cache_inf (current_inferior ());
+  if (objfile == nullptr)
+    invalidate_auxv_cache_inf (current_inferior ());
 }
 
 /* See auxv.h.  */
@@ -613,5 +615,5 @@ This is information provided by the operating system at program startup."));
   /* Observers used to invalidate the auxv cache when needed.  */
   gdb::observers::inferior_exit.attach (invalidate_auxv_cache_inf, "auxv");
   gdb::observers::inferior_appeared.attach (invalidate_auxv_cache_inf, "auxv");
-  gdb::observers::executable_changed.attach (invalidate_auxv_cache, "auxv");
+  gdb::observers::new_objfile.attach (auxv_new_objfile_observer, "auxv");
 }