Re: [patch+7.4] reread.exp 7.3->7.4 regression

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Mon, 19 Dec 2011 11:30:54 +0100, Ulrich Weigand wrote:
> I can test on ARM if you want.

I have tested it on fedora13beta.  Just on

Hardware        : OMAP3 Beagle Board
Revision        : 0020
Processor       : ARMv7 Processor rev 2 (v7l)
BogoMIPS        : 506.27

it takes 57m28.760s to build GDB (although with full symbols) and 51m13.889s
to run the testsuite, is it normal to develop on ARM with this performance?


> I really think this ought to be fixed in reread_symbols;

I did not want to touch it anymore but I see it is currently the most feasible
way how to fix the trunk.


> freeing the old OBFD needs to be done *after* all the callbacks to cleanup
> objfile data have completed.

Done, it follow the free_objfile order now.


> Your initial patch already moved the callbacks calls up a bit;

My patch was using free_objfile, I do not understand which patch of mine do
you refer to now.
	Re: [patch] Replace reread_symbols by load+free calls
	http://sourceware.org/ml/gdb-patches/2009-06/msg00696.html


> In addition, we should probably call observer_notify_new_objfile so that new
> tables can be built up for the re-read file ...

I can post it afterwards, that is probably not for 7.4, I will have to run the
ARM testsuite again.



> > -      if (data != NULL)
> > +      if (data != NULL && sec->the_bfd_section->index < data->section_count)
[...]
> ... and for checks in other users like this to be turned into assertions instead.

On Mon, 19 Dec 2011 16:15:23 +0100, Tom Tromey wrote:
> >>>>> "Jan" == Jan Kratochvil <jan.kratochvil@redhat.com> writes:
> 
> Jan> -      if (data != NULL)
> Jan> +      if (data != NULL && sec->the_bfd_section->index < data->section_count)
> 
> I don't understand the need for this hunk.
> When can this be called in a context where the BFD doesn't match the
> data registered with the objfile?

I did not know this part of code is not affected by the problem.


No regressions on {x86_64,x86_64-m32,i686}-fedora16-linux-gnu and on
arm-fedora13beta-linux-gnu.  OK to check it in and for 7.4?


Thanks,
Jan


gdb/
2011-12-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* symfile.c (reread_symbols): Move free_objfile_separate_debug,
	preserve_values, sym_finish and clear_objfile_data calls before BFD
	close.  Move free_objfile_separate_debug as the very first call.  New
	comment on the ordering.

gdb/testsuite/
2011-12-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.base/reread.exp: If srcfile2 fails to build retry it with
	-DNO_SECTIONS.
	* gdb.base/reread2.c <!NO_SECTIONS>: New sections block.

--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2446,6 +2446,29 @@ reread_symbols (void)
 	      exec_file_attach (bfd_get_filename (objfile->obfd), 0);
 	    }
 
+	  /* Keep the calls order approx. the same as in free_objfile.  */
+
+	  /* Free the separate debug objfiles.  It will be
+	     automatically recreated by sym_read.  */
+	  free_objfile_separate_debug (objfile);
+
+	  /* Remove any references to this objfile in the global
+	     value lists.  */
+	  preserve_values (objfile);
+
+	  /* Nuke all the state that we will re-read.  Much of the following
+	     code which sets things to NULL really is necessary to tell
+	     other parts of GDB that there is nothing currently there.
+
+	     Try to keep the freeing order compatible with free_objfile.  */
+
+	  if (objfile->sf != NULL)
+	    {
+	      (*objfile->sf->sym_finish) (objfile);
+	    }
+
+	  clear_objfile_data (objfile);
+
 	  /* Clean up any state BFD has sitting around.  We don't need
 	     to close the descriptor but BFD lacks a way of closing the
 	     BFD without closing the descriptor.  */
@@ -2471,27 +2494,6 @@ reread_symbols (void)
 	  memcpy (offsets, objfile->section_offsets,
 		  SIZEOF_N_SECTION_OFFSETS (num_offsets));
 
-	  /* Remove any references to this objfile in the global
-	     value lists.  */
-	  preserve_values (objfile);
-
-	  /* Nuke all the state that we will re-read.  Much of the following
-	     code which sets things to NULL really is necessary to tell
-	     other parts of GDB that there is nothing currently there.
-
-	     Try to keep the freeing order compatible with free_objfile.  */
-
-	  if (objfile->sf != NULL)
-	    {
-	      (*objfile->sf->sym_finish) (objfile);
-	    }
-
-	  clear_objfile_data (objfile);
-
-	  /* Free the separate debug objfiles.  It will be
-	     automatically recreated by sym_read.  */
-          free_objfile_separate_debug (objfile);
-
 	  /* FIXME: Do we have to free a whole linked list, or is this
 	     enough?  */
 	  if (objfile->global_psymbols.list)
--- a/gdb/testsuite/gdb.base/reread.exp
+++ b/gdb/testsuite/gdb.base/reread.exp
@@ -38,7 +38,8 @@ set testfile2 "reread2"
 set srcfile2 ${testfile2}.c
 set binfile2 ${objdir}/${subdir}/${testfile2}$EXEEXT
 
-if  { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {debug nowarnings}] != "" } {
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {debug nowarnings}] != ""
+      && [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {debug nowarnings additional_flags=-DNO_SECTIONS}] != ""} {
     untested reread.exp
     return -1
 }
--- a/gdb/testsuite/gdb.base/reread2.c
+++ b/gdb/testsuite/gdb.base/reread2.c
@@ -15,3 +15,14 @@ int main()
   foo();
   return 0;
 }
+
+/* Ensure the new file will have more sections.  It may exploit code not
+   updating its SECTION_COUNT on reread_symbols.  */
+
+#ifndef NO_SECTIONS
+# define VAR0(n) __attribute__ ((section ("sect" #n))) int var##n;
+# define VAR1(n) VAR0 (n ## 0) VAR0(n ## 1) VAR0(n ## 2) VAR0(n ## 3)
+# define VAR2(n) VAR1 (n ## 0) VAR1(n ## 1) VAR1(n ## 2) VAR1(n ## 3)
+# define VAR3(n) VAR2 (n ## 0) VAR2(n ## 1) VAR2(n ## 2) VAR2(n ## 3)
+VAR3 (0)
+#endif