Report vtable changes in top-level function change reports

Up to know we were not reporting vtable changes on top-level function
change reports.  This patch adds that feature.

	* src/abg-comparison.cc (function_decl_diff::report): Report about
	virtual-ness and vtable offset changes.
	* tests/data/test-diff-dwarf/test28-vtable-changes-report-0.txt:
	New test input file.
	* tests/data/test-diff-dwarf/test28-vtable-changes-v{0,1}.o: New
	test input binaries.
	* tests/data/test-diff-dwarf/test28-vtable-changes-v{0,1}.cc:
	Source code of the input binaries above.
	* tests/data/Makefile.am: Add the new test input above to source
	distribution.
	* tests/test-diff-dwarf.cc (in_out_specs): Add the new test input
	above to the list of input this test harness has to run over.

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

src/abg-comparison.cc

@@ -10576,6 +10576,34 @@ function_decl_diff::report(ostream& out, const string& indent) const
 	    << " is now declared inline\n";
     }
 
+  // Report about vtable offset changes.
+  if (is_member_function(ff) && is_member_function(sf))
+    {
+      bool ff_is_virtual = get_member_function_is_virtual(ff),
+	sf_is_virtual = get_member_function_is_virtual(sf);
+      if (ff_is_virtual != sf_is_virtual)
+	{
+	  out << indent;
+	  if (ff_is_virtual)
+	    out << ff->get_pretty_representation()
+		<< " is no more declared virtual\n";
+	  else
+	    out << ff->get_pretty_representation()
+		<< " is now declared virtual\n";
+	}
+
+      size_t ff_vtable_offset = get_member_function_vtable_offset(ff),
+	sf_vtable_offset = get_member_function_vtable_offset(sf);
+      if (ff_is_virtual && sf_is_virtual
+	  && (ff_vtable_offset != sf_vtable_offset))
+	{
+	  out << indent
+	      << "the vtable offset of "  << ff->get_pretty_representation()
+	      << " changed from " << ff_vtable_offset
+	      << " to " << sf_vtable_offset << "\n";
+	}
+    }
+
   // Report about function type differences.
   if (type_diff() && type_diff()->to_be_reported())
     type_diff()->report(out, indent);

tests/data/Makefile.am

@@ -212,6 +212,11 @@ test-diff-dwarf/test27-local-base-diff-v1.o \
 test-diff-dwarf/test27-local-base-diff-v0.cc \
 test-diff-dwarf/test27-local-base-diff-v1.cc \
 test-diff-dwarf/test27-local-base-diff-report.txt \
+test-diff-dwarf/test28-vtable-changes-report-0.txt \
+test-diff-dwarf/test28-vtable-changes-v0.o \
+test-diff-dwarf/test28-vtable-changes-v1.o \
+test-diff-dwarf/test28-vtable-changes-v0.cc \
+test-diff-dwarf/test28-vtable-changes-v1.cc \
 \
 test-read-dwarf/test0			\
 test-read-dwarf/test0.abi			\

tests/data/test-diff-dwarf/test28-vtable-changes-report-0.txt

@@ -0,0 +1,22 @@
+Functions changes summary: 0 Removed, 1 Changed, 2 Added functions
+Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
+Function symbols changes summary: 0 Removed, 0 Added function symbol not referenced by debug info
+Variable symbols changes summary: 0 Removed, 3 Added function symbols not referenced by debug info
+
+2 Added functions:
+
+  'method virtual S::~S(int)'
+  'method virtual S::~S(int)'
+
+1 function with some indirect sub-type change:
+
+  [C]'method void S::bar()' has some indirect sub-type changes:
+    method void S::bar() is now declared virtual
+
+
+3 Added variable symbols not referenced by debug info:
+
+  _ZTI1S, aliases _ZTS1S
+  _ZTS1S
+  _ZTV1S, aliases _ZTI1S, _ZTS1S
+

tests/data/test-diff-dwarf/test28-vtable-changes-v0.cc

@@ -0,0 +1,26 @@
+// Compile with:
+//   g++ -g -Wall -c test28-vtable-changes-v0.cc
+
+struct S
+{
+  void
+  bar();
+
+  virtual void
+  baz();
+
+  virtual void
+  foo();
+};
+
+void
+S::bar()
+{}
+
+void
+baz()
+{}
+
+void
+foo()
+{}

tests/data/test-diff-dwarf/test28-vtable-changes-v1.cc

@@ -0,0 +1,32 @@
+// Compile with:
+//   g++ -g -Wall -c test28-vtable-changes-v1.cc
+
+
+struct S
+{
+  virtual void
+  bar();
+
+  virtual void
+  baz();
+
+  virtual void
+  foo();
+
+  virtual ~S();
+};
+
+void
+S::bar()
+{}
+
+void
+baz()
+{}
+
+void
+foo()
+{}
+
+S::~S()
+{}

tests/test-diff-dwarf.cc

@@ -230,6 +230,12 @@ InOutSpec in_out_specs[] =
     "data/test-diff-dwarf/test27-local-base-diff-report.txt",
     "output/test-diff-dwarf/test27-local-base-diff-report.txt"
   },
+  {
+    "data/test-diff-dwarf/test28-vtable-changes-v0.o",
+    "data/test-diff-dwarf/test28-vtable-changes-v1.o",
+    "data/test-diff-dwarf/test28-vtable-changes-report-0.txt",
+    "output/test-diff-dwarf/test28-vtable-changes-report-0.txt"
+  },
   // This should be the last entry
   {NULL, NULL, NULL, NULL}
 };