| Message ID | m33876ary6.fsf@sspiff.org |
|---|---|
| State | New |
| Headers | show |
On 01/20/2015 06:26 AM, Doug Evans wrote: > Hi. > > This patch fixes symtab/17855. > Basically the issue is that breakpoint_re_set is currently being called > before observer_notify_new_objfile (NULL), and thus the ada symbol > cache (and the general symbol cache of a separate patch) aren't being > flushed first, so that when breakpoints are reset symbol lookup is being > done on a stale cache. > > Regression tested on amd64-linux. > > 2015-01-19 Doug Evans <xdje42@gmail.com> > > PR symtab/17855 > * symfile.c (clear_symtab_users): Notify observers of change before > calling breakpoint_re_set. > > diff --git a/gdb/symfile.c b/gdb/symfile.c > index d55e361..ad481de 100644 > --- a/gdb/symfile.c > +++ b/gdb/symfile.c > @@ -3023,6 +3023,12 @@ clear_symtab_users (int add_flags) > /* Someday, we should do better than this, by only blowing away > the things that really need to be blown. */ > > + /* Notify anyone listening that the previous loaded symtab(s) are invalid. > + It is important to do this before calling breakpoint_re_set as the latter > + will try to look up symbols, and for example the symbol cache needs to > + be flushed first. */ > + observer_notify_new_objfile (NULL); > + > /* Clear the "current" symtab first, because it is no longer valid. > breakpoint_re_set may try to access the current symtab. */ > clear_current_source_symtab_and_line (); > @@ -3032,7 +3038,6 @@ clear_symtab_users (int add_flags) > breakpoint_re_set (); > clear_last_displayed_sal (); > clear_pc_function_cache (); > - observer_notify_new_objfile (NULL); Looking at the whole function, ISTM that the breakpoint_re_set call should move further down. I can imagine that breakpoint_re_set could well hit a stale pc function cache, cleared only after by clear_pc_function_cache. breakpoint.c:parse_breakpoint_sals also references the last displayed sal. One would hope that breakpoint re-set is independent of that, though the existing comment about breakpoint_re_set accessing the current symtab leaves me wondering. WDYT? Thanks, Pedro Alves
On Thu, Jan 22, 2015 at 3:41 AM, Pedro Alves <palves@redhat.com> wrote: > Looking at the whole function, ISTM that the breakpoint_re_set > call should move further down. I can imagine that breakpoint_re_set > could well hit a stale pc function cache, cleared only after by > clear_pc_function_cache. breakpoint.c:parse_breakpoint_sals also > references the last displayed sal. One would hope that breakpoint > re-set is independent of that, though the existing comment about > breakpoint_re_set accessing the current symtab leaves me > wondering. WDYT? Fine by me.
diff --git a/gdb/symfile.c b/gdb/symfile.c index d55e361..ad481de 100644 --- a/gdb/symfile.c +++ b/gdb/symfile.c @@ -3023,6 +3023,12 @@ clear_symtab_users (int add_flags) /* Someday, we should do better than this, by only blowing away the things that really need to be blown. */ + /* Notify anyone listening that the previous loaded symtab(s) are invalid. + It is important to do this before calling breakpoint_re_set as the latter + will try to look up symbols, and for example the symbol cache needs to + be flushed first. */ + observer_notify_new_objfile (NULL); + /* Clear the "current" symtab first, because it is no longer valid. breakpoint_re_set may try to access the current symtab. */ clear_current_source_symtab_and_line (); @@ -3032,7 +3038,6 @@ clear_symtab_users (int add_flags) breakpoint_re_set (); clear_last_displayed_sal (); clear_pc_function_cache (); - observer_notify_new_objfile (NULL); /* Clear globals which might have pointed into a removed objfile. FIXME: It's not clear which of these are supposed to persist