[v2] Fix has_net_changes for --leaf-changes-only mode.

  This function was not aware of --leaf-changes-only mode.

    - Stats counters for changed variables and types have
      different names in the different modes.
    - Leaf type changes were not included in leaf mode.

For some inputs, this resulted in abidiff producing an empty report but
returning a non-zero exit status in --leaf-changes-only mode.

For other inputs, including some existing tests, the combination of
both issues still resulted in the correct return code.

This patch makes has_net_changes mirror emit_diff_stats, modulo flags
like --non-reachable-types which if absent can still result in
discrepancies between output and return code.

	* src/abg-comparison.cc
	(corpus_diff::priv::emit_diff_stats): Code whitespace.
	(corpus_diff::has_net_changes): Reorder the logic to match
	emit_diff_stats, add a note about this; in --leaf-changes-only
	mode use the right counters for function and variable changes
	and include type changes.

Signed-off-by: Giuliano Procida <gprocida@google.com>
---
 src/abg-comparison.cc | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)
  

On Fri, Mar 27, 2020 at 07:01:35PM +0000, Giuliano Procida wrote:
>This function was not aware of --leaf-changes-only mode.
>
>    - Stats counters for changed variables and types have
>      different names in the different modes.
>    - Leaf type changes were not included in leaf mode.
>
>For some inputs, this resulted in abidiff producing an empty report but
>returning a non-zero exit status in --leaf-changes-only mode.
>
>For other inputs, including some existing tests, the combination of
>both issues still resulted in the correct return code.
>
>This patch makes has_net_changes mirror emit_diff_stats, modulo flags
>like --non-reachable-types which if absent can still result in
>discrepancies between output and return code.
>
>	* src/abg-comparison.cc
>	(corpus_diff::priv::emit_diff_stats): Code whitespace.
>	(corpus_diff::has_net_changes): Reorder the logic to match
>	emit_diff_stats, add a note about this; in --leaf-changes-only
>	mode use the right counters for function and variable changes
>	and include type changes.
>
>Signed-off-by: Giuliano Procida <gprocida@google.com>

Would feel better to have some tests covering this along with the patch.
But this still looks correct to me.

Reviewed-by: Matthias Maennich <maennich@google.com>

Cheers,
Matthias

>---
> src/abg-comparison.cc | 30 ++++++++++++++++++------------
> 1 file changed, 18 insertions(+), 12 deletions(-)
>
>diff --git a/src/abg-comparison.cc b/src/abg-comparison.cc
>index 46bf9e30..50791cb5 100644
>--- a/src/abg-comparison.cc
>+++ b/src/abg-comparison.cc
>@@ -9932,7 +9932,7 @@ corpus_diff::priv::emit_diff_stats(const diff_stats&	s,
> 	out << " (" << s.num_changed_func_filtered_out() << " filtered out)";
>       out << ", ";
>
>-      out << s.net_num_func_added()<< " Added";
>+      out << s.net_num_func_added() << " Added";
>       if (s.num_added_func_filtered_out())
> 	out << " (" << s.num_added_func_filtered_out() << " filtered out)";
>       if (total_nb_function_changes <= 1)
>@@ -10560,7 +10560,7 @@ corpus_diff::has_incompatible_changes() const
> 	  || stats.net_num_func_removed() != 0
> 	  || (stats.num_func_with_virtual_offset_changes() != 0
> 	      // If all reports about functions with sub-type changes
>-	      // have been suppressd, then even those about functions
>+	      // have been suppressed, then even those about functions
> 	      // that are virtual don't matter anymore because the
> 	      // user willingly requested to shut them down
> 	      && stats.net_num_func_changed() != 0)
>@@ -10602,21 +10602,27 @@ corpus_diff::has_net_changes() const
>     const diff_stats& stats = const_cast<corpus_diff*>(this)->
>       apply_filters_and_suppressions_before_reporting();
>
>+    // Logic here should match emit_diff_stats.
>+    // TODO: Possibly suppress things that won't be shown there.
>+    bool leaf = context()->show_leaf_changes_only();
>     return (architecture_changed()
> 	    || soname_changed()
>-	    || stats.net_num_func_changed()
>-	    || stats.net_num_vars_changed()
>-	    || stats.net_num_func_added()
>-	    || stats.net_num_added_func_syms()
> 	    || stats.net_num_func_removed()
>-	    || stats.net_num_removed_func_syms()
>-	    || stats.net_num_vars_added()
>-	    || stats.net_num_added_var_syms()
>+	    || (leaf && stats.num_leaf_type_changes())
>+	    || (leaf ? stats.net_num_leaf_func_changes()
>+		     : stats.net_num_func_changed())
>+	    || stats.net_num_func_added()
> 	    || stats.net_num_vars_removed()
>-	    || stats.net_num_removed_var_syms()
>-	    || stats.net_num_added_unreachable_types()
>+	    || (leaf ? stats.net_num_leaf_var_changes()
>+		     : stats.net_num_vars_changed())
>+	    || stats.net_num_vars_added()
> 	    || stats.net_num_removed_unreachable_types()
>-	    || stats.net_num_changed_unreachable_types());
>+	    || stats.net_num_changed_unreachable_types()
>+	    || stats.net_num_added_unreachable_types()
>+	    || stats.net_num_removed_func_syms()
>+	    || stats.net_num_added_func_syms()
>+	    || stats.net_num_removed_var_syms()
>+	    || stats.net_num_added_var_syms());
> }
>
> /// Apply the different filters that are registered to be applied to
>-- 
>2.26.0.rc2.310.g2932bb562d-goog
>