[binutils-gdb] Guard against frame.c destructors running before frame-info.c's

["Kévin Le Gouguec" <legouguec@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=995a34b1772f1c04d6a98641c6d29d68628b9063

commit 995a34b1772f1c04d6a98641c6d29d68628b9063
Author: Kévin Le Gouguec <legouguec@adacore.com>
Date:   Tue Nov 15 16:08:04 2022 +0100

    Guard against frame.c destructors running before frame-info.c's
    
    On x86_64-windows, since 04e2ac7b2a7, we observe this internal error:
    
      [...]/gdbsupport/intrusive_list.h:458: internal-error: erase_element:
      Assertion `elem_node->prev != INTRUSIVE_LIST_UNLINKED_VALUE' failed.
    
    Breaking in the destructors for intrusive_list and frame_info_ptr shows that
    in this configuration, the destructors for frame.c's statically-stored
    objects are run before frame-info.c's:
    
      Thread 1 hit Breakpoint 7, intrusive_list<frame_info_ptr,
      intrusive_base_node<frame_info_ptr> >::~intrusive_list (this=0x7ff69c418c90
      <frame_info_ptr::frame_list>, __in_chrg=<optimized out>)
      [...]/../gdbsupport/intrusive_list.h:250
      250       clear ();
      (gdb) bt
      #0  intrusive_list<frame_info_ptr, intrusive_base_node<frame_info_ptr> >
          ::~intrusive_list (this=0x7ff69c418c90 <frame_info_ptr::frame_list>,
          __in_chrg=<optimized out>) [...]/../gdbsupport/intrusive_list.h:250
      #1  0x00007ff69b78edba in __tcf_1 () [...]/frame-info.c:27
      #2  0x00007ff9c457aa9f in msvcrt!_initterm_e ()
          from C:\Windows\System32\msvcrt.dll
      #3  0x00007ff69b8246a6 in captured_main_1 (context=0x5ffe00)
          [...]/main.c:1111
      #4  0x00007ff69b825149 in captured_main (data=0x5ffe00) [...]/main.c:1320
      #5  0x00007ff69b8251b1 in gdb_main (args=0x5ffe00) [...]/main.c:1345
      #6  0x00007ff69b5d1730 in main (argc=2, argv=0x751730) [...]/gdb.c:32
      (gdb) c
      Continuing.
    
      Thread 1 hit Breakpoint 8, frame_info_ptr::~frame_info_ptr
      (this=0x7ff69c418e20 <selected_frame>, __in_chrg=<optimized out>)
      [...]/frame-info.h:74
      74        if (is_linked ())
      (gdb) bt
      #0  frame_info_ptr::~frame_info_ptr (this=0x7ff69c418e20 <selected_frame>,
          __in_chrg=<optimized out>) [...]/frame-info.h:74
      #1  0x00007ff69b79a643 in __tcf_1 () [...]/frame.c:1675
      #2  0x00007ff9c457aa9f in msvcrt!_initterm_e () from
          C:\Windows\System32\msvcrt.dll
      #3  0x00007ff69b8246a6 in captured_main_1 (context=0x5ffe00)
          [...]/main.c:1111
      #4  0x00007ff69b825149 in captured_main (data=0x5ffe00) [...]/main.c:1320
      #5  0x00007ff69b8251b1 in gdb_main (args=0x5ffe00) [...]/main.c:1345
      #6  0x00007ff69b5d1730 in main (argc=2, argv=0x751730) [...]/gdb.c:32
    
    Approved-By: Simon Marchi <simon.marchi@efficios.com>

Diff:
---
 gdb/frame-info.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/frame-info.h b/gdb/frame-info.h
index 3369b114326..893b6632363 100644
--- a/gdb/frame-info.h
+++ b/gdb/frame-info.h
@@ -76,7 +76,11 @@ public:
 
   ~frame_info_ptr ()
   {
-    frame_list.erase (frame_list.iterator_to (*this));
+    /* If this node has static storage, it may be deleted after
+       frame_list.  Attempting to erase ourselves would then trigger
+       internal errors, so make sure we are still linked first.  */
+    if (is_linked ())
+      frame_list.erase (frame_list.iterator_to (*this));
   }
 
   frame_info_ptr &operator= (const frame_info_ptr &other)