Add a new DECL_NAME_CHANGE_CATEGORY change category

* include/abg-comparison.h (enum
	diff_category::DECL_NAME_CHANGE_CATEGORY): New enumerator.
	* src/abg-comparison.cc (report_name_size_and_alignment_changes)
	({enum, typedef}_diff::report): Adjust to avoid emitting name
	change report if the DECL_NAME_CHANGE_CATEGORY category of change
	is currently disallowed.
	* abg-comp-filter.cc (decl_name_changed): New static function.
	(harmless_filter::visit): Detect that the decl name changed and
	put the current diff node (and its parents) into the
	DECL_NAME_CHANGE_CATEGORY category.
	* tools/bidiff.cc (set_diff_context_from_opts): Set the new
	DECL_NAME_CHANGE_CATEGORY category into the harmless_changes group
	of categories.
	* tests/data/test-diff-filter/test6-report.txt: New test input file.
	* tests/data/test-diff-filter/test6-v0.cc: Likewise.
	* tests/data/test-diff-filter/test6-v0.o: Likewise.
	* tests/data/test-diff-filter/test6-v1.cc: Likewise.
	* tests/data/test-diff-filter/test6-v1.o: Likewise.
	* tests/data/test-diff-filter/test7-report.txt: Likewise.
	* tests/data/test-diff-filter/test7-v0.cc: Likewise.
	* tests/data/test-diff-filter/test7-v0.o: Likewise.
	* tests/data/test-diff-filter/test7-v1.cc: Likewise.
	* tests/data/test-diff-filter/test7-v1.o: Likewise.
	* tests/test-diff-filter.cc: Take the new inputs above to run new tests.
	* tests/Makefile.am: Add the new files above to the distribution.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

include/abg-comparison.h

@@ -224,10 +224,14 @@ enum diff_category
   /// instance a type and its typedefs.
   COMPATIBLE_TYPE_CHANGE_CATEGORY = 1 << 1,
 
+  /// This means that a diff node in the sub-tree carries a
+  /// declaration name change.
+  DECL_NAME_CHANGE_CATEGORY = 1 << 2,
+
   /// This means the diff node (or at least one of its descendant
   /// nodes) carries a change that modifies the size of a type or an
   /// offset of a type member.
-  SIZE_OR_OFFSET_CHANGE_CATEGORY = 1 << 2,
+  SIZE_OR_OFFSET_CHANGE_CATEGORY = 1 << 3,
 
   /// A special enumerator that is the logical 'or' all the
   /// enumerators above.
@@ -237,6 +241,7 @@ enum diff_category
   EVERYTHING_CATEGORY =
   ACCESS_CHANGE_CATEGORY
   | COMPATIBLE_TYPE_CHANGE_CATEGORY
+  | DECL_NAME_CHANGE_CATEGORY
   | SIZE_OR_OFFSET_CHANGE_CATEGORY
 };
 

src/abg-comp-filter.cc

@@ -150,6 +150,26 @@ is_compatible_change(decl_base_sptr d1, decl_base_sptr d2)
   return false;
 }
 
+/// Test if two decls have different names.
+///
+/// @param d1 the first declaration to consider.
+///
+/// @param d2 the second declaration to consider.
+///
+/// @return true if d1 and d2 have different names.
+static bool
+decl_name_changed(decl_base_sptr d1, decl_base_sptr d2)
+{
+  string d1_name, d2_name;
+
+  if (d1)
+    d1_name = d1->get_name();
+  if (d2)
+    d2_name = d2->get_name();
+
+  return d1_name != d2_name;
+}
+
 /// The visiting code of the harmless_filter.
 ///
 /// @param d the diff node being visited.
@@ -175,6 +195,9 @@ harmless_filter::visit(diff* d, bool pre)
       if (is_compatible_change(f, s))
 	category |= COMPATIBLE_TYPE_CHANGE_CATEGORY;
 
+      if (decl_name_changed(f, s))
+	category |= DECL_NAME_CHANGE_CATEGORY;
+
       if (category)
 	d->add_to_category(category);
     }

src/abg-comparison.cc

@@ -1178,7 +1178,8 @@ report_name_size_and_alignment_changes(decl_base_sptr		first,
   string fn = first->get_qualified_name(),
     sn = second->get_qualified_name();
 
-  if (fn != sn)
+  if (fn != sn
+      && ctxt->get_allowed_category() & DECL_NAME_CHANGE_CATEGORY)
     {
       if (nl)
 	out << "\n";
@@ -2171,7 +2172,8 @@ enum_diff::report(ostream& out, const string& indent) const
   maybe_report_diff_for_member(first, second, context(), out, indent);
 
   // name
-  if (first->get_name() != second->get_name())
+  if (first->get_name() != second->get_name()
+      && context()->get_allowed_category() & DECL_NAME_CHANGE_CATEGORY)
     out << indent << "enum name changed from '"
 	<< first->get_qualified_name() << "' to '"
 	<< second->get_qualified_name() << "'\n";
@@ -5011,7 +5013,8 @@ typedef_diff::report(ostream& out, const string& indent) const
 
   maybe_report_diff_for_member(f, s, context(), out, indent);
 
-  if (f->get_name() != s->get_name())
+  if (f->get_name() != s->get_name()
+      && context()->get_allowed_category() & DECL_NAME_CHANGE_CATEGORY)
     {
       out << indent << "typedef name changed from "
 	  << f->get_qualified_name()

tests/Makefile.am

@@ -174,7 +174,17 @@ data/test-diff-filter/test5-v0.cc		\
 data/test-diff-filter/test5-v1.cc		\
 data/test-diff-filter/test5-v0.o		\
 data/test-diff-filter/test5-v1.o		\
-data/test-diff-filter/test5-report.txt
+data/test-diff-filter/test5-report.txt		\
+data/test-diff-filter/test6-v0.cc		\
+data/test-diff-filter/test6-v1.cc		\
+data/test-diff-filter/test6-v0.o		\
+data/test-diff-filter/test6-v1.o		\
+data/test-diff-filter/test6-report.txt		\
+data/test-diff-filter/test7-v0.cc		\
+data/test-diff-filter/test7-v1.cc		\
+data/test-diff-filter/test7-v0.o		\
+data/test-diff-filter/test7-v1.o		\
+data/test-diff-filter/test7-report.txt
 
 clean-local: clean-local-check
 .PHONY: clean-local-check

tests/data/test-diff-filter/test6-report.txt

@@ -0,0 +1,11 @@
+Functions changes summary: 0 Removed, 1 Changed, 0 Added function
+Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
+
+1 function with some indirect sub-type change:
+
+  [C]'function return_type foo()' has some indirect sub-type changes:
+    return type changed:
+      underlying type 'unsigned char' changed:
+        size changed from 8 to 32 bits
+        alignment changed from 8 to 32 bits
+

tests/data/test-diff-filter/test6-v0.cc

@@ -0,0 +1,5 @@
+typedef unsigned char return_type;
+
+return_type
+foo()
+{return 0;}

tests/data/test-diff-filter/test6-v1.cc

@@ -0,0 +1,5 @@
+typedef unsigned int return_type;
+
+return_type
+foo()
+{return 0;}

tests/data/test-diff-filter/test7-report.txt

@@ -0,0 +1,4 @@
+Functions changes summary: 0 Removed, 0 Changed (1 filtered out), 0 Added function
+Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
+
+

tests/data/test-diff-filter/test7-v0.cc

@@ -0,0 +1,8 @@
+struct return_type
+{
+  unsigned char m0;
+};
+
+return_type
+foo()
+{return return_type();}

tests/data/test-diff-filter/test7-v1.cc

@@ -0,0 +1,8 @@
+struct other_return_type
+{
+  unsigned char m0;
+};
+
+other_return_type
+foo()
+{return other_return_type();}

tests/test-diff-filter.cc

@@ -103,6 +103,20 @@ InOutSpec in_out_specs[] =
     "data/test-diff-filter/test5-report.txt",
     "output/test-diff-filter/test5-report.txt",
   },
+  {
+    "data/test-diff-filter/test6-v0.o",
+    "data/test-diff-filter/test6-v1.o",
+    "--no-harmless",
+    "data/test-diff-filter/test6-report.txt",
+    "output/test-diff-filter/test6-report.txt",
+  },
+  {
+    "data/test-diff-filter/test7-v0.o",
+    "data/test-diff-filter/test7-v1.o",
+    "--no-harmless",
+    "data/test-diff-filter/test7-report.txt",
+    "output/test-diff-filter/test7-report.txt",
+  },
   // This should be the last entry
   {NULL, NULL, NULL, NULL, NULL}
 };

tools/bidiff.cc

@@ -294,7 +294,8 @@ set_diff_context_from_opts(diff_context_sptr ctxt,
 
   if (!opts.show_harmless_changes)
       ctxt->switch_categories_off(abigail::comparison::ACCESS_CHANGE_CATEGORY
-				  | abigail::comparison::COMPATIBLE_TYPE_CHANGE_CATEGORY);
+				  | abigail::comparison::COMPATIBLE_TYPE_CHANGE_CATEGORY
+				  | abigail::comparison::DECL_NAME_CHANGE_CATEGORY);
   if (!opts.show_harmful_changes)
     ctxt->switch_categories_off(abigail::comparison::SIZE_OR_OFFSET_CHANGE_CATEGORY);
 }