[review,v3] jit: remove bp locations when unregistering jit code

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 904abda..ab1139d 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -3066,6 +3066,50 @@ 
   }
 }
 
+/* Tries to find `bp` in the linked list of `b` locations
+   and if found, removes it.  In practice that means that breakpoint
+   will forget about this location and won't try to re-insert it.  */
+
+static bool
+remove_location_from_bp (breakpoint *b, bp_location *bp)
+{
+  if (b->loc == bp)
+    {
+      b->loc = nullptr;
+      return true;
+    }
+
+  bp_location *i;
+  for (i = b->loc; i != nullptr && i->next != bp; i = i->next)
+    ;
+  if (i == nullptr)
+    return false;
+  i->next = i->next->next;
+  return true;
+}
+
+/* See breakpoint.h.  */
+
+int
+forget_breakpoint_locations_obj (objfile *obj)
+{
+  struct bp_location **blp, *bl;
+
+  int count = 0;
+
+  ALL_BP_LOCATIONS (bl, blp)
+  {
+    if (is_addr_in_objfile (bl->address, obj))
+      {
+	bool ret = remove_location_from_bp (bl->owner, bl);
+	gdb_assert (ret);
+	++count;
+      }
+  }
+
+  return count;
+}
+
 static int internal_breakpoint_number = -1;
 
 /* Set the breakpoint number of B, depending on the value of INTERNAL.
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 3197854..9105970 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1411,6 +1411,13 @@ 
 
 extern void remove_breakpoints_inf (inferior *inf);
 
+/* Forgets all breakpoint locations that are inserted
+   for a given objfile by removing them from the owning breakpoint
+   linked list.  Will not affect actual breakpoints and
+   if the object file remains these may be re-created during next
+   `update_breakpoint_locations` call.  */
+extern int forget_breakpoint_locations_obj (objfile* obj);
+
 /* This function can be used to update the breakpoint package's state
    after an exec() system call has been executed.
 
diff --git a/gdb/jit.c b/gdb/jit.c
index 0dd11e1..6ed5f51 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -923,6 +923,32 @@ 
   return NULL;
 }
 
+/* This function unregisters JITed code and does the necessary cleanup.  */
+
+static void
+jit_unregister_code (struct gdbarch *gdbarch, CORE_ADDR entry_addr)
+{
+  struct objfile *objfile = nullptr;
+  if (jit_debug)
+    fprintf_unfiltered (gdb_stdlog, "jit_unregister_code (%s)\n",
+			host_address_to_string (objfile));
+  objfile = jit_find_objf_with_entry_addr (entry_addr);
+  if (objfile == NULL)
+    printf_unfiltered (_ ("Unable to find JITed code "
+			  "entry at address: %s\n"),
+		       paddress (gdbarch, entry_addr));
+  else
+    {
+      int count = forget_breakpoint_locations_obj (objfile);
+      if (jit_debug && count > 0)
+	fprintf_unfiltered (gdb_stdlog,
+			    "jit_unregister_code, ignoring %d breakpoint"
+			    "locations in the unregistered code\n",
+			    count);
+      objfile->unlink ();
+    }
+}
+
 /* This is called when a breakpoint is deleted.  It updates the
    inferior's cache, if needed.  */
 
@@ -1333,7 +1359,6 @@ 
   struct jit_descriptor descriptor;
   struct jit_code_entry code_entry;
   CORE_ADDR entry_addr;
-  struct objfile *objf;
 
   /* Read the descriptor from remote memory.  */
   if (!jit_read_descriptor (gdbarch, &descriptor,
@@ -1351,14 +1376,7 @@ 
       jit_register_code (gdbarch, entry_addr, &code_entry);
       break;
     case JIT_UNREGISTER:
-      objf = jit_find_objf_with_entry_addr (entry_addr);
-      if (objf == NULL)
-	printf_unfiltered (_("Unable to find JITed code "
-			     "entry at address: %s\n"),
-			   paddress (gdbarch, entry_addr));
-      else
-	objf->unlink ();
-
+      jit_unregister_code (gdbarch, entry_addr);
       break;
     default:
       error (_("Unknown action_flag value in JIT descriptor!"));
diff --git a/gdb/testsuite/gdb.base/jit-reregister.c b/gdb/testsuite/gdb.base/jit-reregister.c
new file mode 100644
index 0000000..3d63f14
--- /dev/null
+++ b/gdb/testsuite/gdb.base/jit-reregister.c
@@ -0,0 +1,58 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2019 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "jit-defs.h"
+#include "jit-elf.h"
+
+int
+main (int argc, char *argv[])
+{
+  size_t obj_size;
+  ElfW (Addr) addr = load_elf (argv[1], &obj_size, 0);
+  update_locations (addr, -1);
+  int (*jit_function) ()
+      = (int (*) ()) load_symbol (addr, "jit_function_XXXX");
+
+  struct jit_code_entry *const entry
+      = (struct jit_code_entry *) calloc (1, sizeof (*entry));
+
+  entry->symfile_addr = (const char *) addr;
+  entry->symfile_size = obj_size;
+  entry->prev_entry = __jit_debug_descriptor.relevant_entry;
+  __jit_debug_descriptor.relevant_entry = entry;
+  __jit_debug_descriptor.first_entry = entry;
+  __jit_debug_descriptor.action_flag = JIT_REGISTER_FN;
+  __jit_debug_register_code ();
+
+  jit_function (); /* first-call */
+
+  __jit_debug_descriptor.action_flag = JIT_UNREGISTER_FN;
+  __jit_debug_register_code ();
+
+  addr = load_elf (argv[1], &obj_size, addr);
+  update_locations (addr, -1);
+  jit_function = (int (*) ()) load_symbol (addr, "jit_function_XXXX");
+
+  entry->symfile_addr = (const char *) addr;
+  entry->symfile_size = obj_size;
+  __jit_debug_descriptor.relevant_entry = entry;
+  __jit_debug_descriptor.first_entry = entry;
+  __jit_debug_descriptor.action_flag = JIT_REGISTER_FN;
+  __jit_debug_register_code ();
+
+  jit_function ();
+}
diff --git a/gdb/testsuite/gdb.base/jit-reregister.exp b/gdb/testsuite/gdb.base/jit-reregister.exp
new file mode 100644
index 0000000..23de587
--- /dev/null
+++ b/gdb/testsuite/gdb.base/jit-reregister.exp
@@ -0,0 +1,45 @@ 
+# Copyright 2019 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+#
+# Tests global symbol lookup in case a symbol's name in the kernel
+# coincides with another in the main executable.
+
+standard_testfile .c
+
+if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
+    return -1
+}
+
+set solib "jit-solib"
+set solib_src "${srcdir}/${subdir}/${solib}.c"
+set solib_bin [standard_output_file ${solib}.so]
+
+if { [gdb_compile_shlib "${solib_src}" "${solib_bin}" {debug}] != "" } {
+    untested "failed to compile jit shared library"
+    return -1
+}
+
+set solib_bin_target [gdb_remote_download target ${solib_bin}]
+
+clean_restart ${binfile}
+
+gdb_test "start ${solib_bin_target}"
+gdb_breakpoint [gdb_get_line_number "first-call"] {temporary}
+gdb_test "set debug jit 1"
+gdb_continue_to_breakpoint "first-call"
+
+gdb_breakpoint "jit_function_XXXX"
+gdb_continue_to_breakpoint "jit_function_XXXX"
+gdb_continue_to_breakpoint "jit_function_XXXX"
\ No newline at end of file