C++ support for -Wunused-but-set-variable

gcc/cp/ChangeLog:
	PR 18624
	* cp-tree.h (mark_exp_read, mark_rvalue_use, mark_lvalue_use,
	mark_type_use): Declare ...
	* expr.c (mark_exp_read, mark_rvalue_use, mark_lvalue_use,
	mark_type_use): ... new fns.
	* typeck.c (cxx_sizeof_expr, cxx_alignof_expr): Call mark_type_use.
	(perform_integral_promotions): Call mark_rvalue_use.
	(cp_build_unary_op): Call mark_lvalue_use.
	(decay_conversion): Update comment. Call mark_lvalue.
	* decl.c (unused_but_set_errorcount): New variable.
	(poplevel): Issue -Wunused-but-set-variable diagnostics.
	(duplicate_decls): Merge DECL_READ_P flags.
	(start_cleanup_fn): Set DECL_READ_P flag.
	(finish_function): Issue -Wunused-but-set-parameter diagnostics.
	* tree.c (rvalue): Call mark_rvalue_use.
	* pt.c (convert_nontype_argument): Likewise.
	* semantics.c (finish_typeof, finish_decltype_type): Call
	mark_type_use.
	(finish_asm_stmt): Call mark_lvalue_use.
	(finish_expr_stmt): Call mark_exp_read.
	* call.c (convert_like_real) <ck_identity, ck_user>: Call
	mark_rvalue_use.
	(build_x_va_arg): Call mark_lvalue_use.
	(build_over_call): Call mark_type_use.
	* init.c (build_new, build_delete): Call mark_value_use.
	* rtti.c (build_typeid): Call mark_lvalue_use or mark_type_use.
	(build_dynamic_cast_1): call mark_lvalue_use or mark_rvalue_use.

gcc/testsuite/ChangeLog:
	PR 18624
	* g++.dg/warn/Wunused-7.C: Add dg-warning.
	* g++.dg/template/sfinae16.C: Likewise.
	* gcc.dg/Wunused-var-1.c: Moved to...
	* c-c++-common/Wunused-var-1.c: ...here. New test.
	* gcc.dg/Wunused-var-2.c: Moved to...
	* c-c++-common/Wunused-var-2.c: ...here. New test.
	* gcc.dg/Wunused-var-3.c: Moved to...
	* c-c++-common/Wunused-var-3.c: ...here. New test.
	* gcc.dg/Wunused-var-4.c: Moved to...
	* gcc.dg/Wunused-var-1.c: ... here.
	* gcc.dg/Wunused-var-5.c: Moved to...
	* c-c++-common/Wunused-var-4.c: ...here. New test.
	* gcc.dg/Wunused-var-7.c: Moved to...
	* c-c++-common/Wunused-var-5.c: ...here. New test.
	* gcc.dg/Wunused-var-6.c: Moved to...
	* gcc.dg/Wunused-var-2.c: ... here.
	* c-c++-common/Wunused-var-1.c: New test.
	* c-c++-common/Wunused-var-2.c: New test.
	* c-c++-common/Wunused-var-3.c: New test.
	* c-c++-common/Wunused-var-4.c: New test.
	* c-c++-common/Wunused-var-5.c: New test.
	* g++.dg/warn/Wunused-var-1.C: New test.
	* g++.dg/warn/Wunused-var-2.C: New test.
	* g++.dg/warn/Wunused-var-3.C: New test.
	* g++.dg/warn/Wunused-var-4.C: New test.
	* g++.dg/warn/Wunused-var-5.C: New test.
	* g++.dg/warn/Wunused-var-6.C: New test.
	* g++.dg/warn/Wunused-var-7.C: New test.
	* g++.dg/warn/Wunused-var-8.C: New test.
	* g++.dg/warn/Wunused-parm-1.C: New test.
	* g++.dg/warn/Wunused-parm-2.C: New test.
	* g++.dg/warn/Wunused-parm-3.C: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@159096 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 104 insertions, 0 deletions

diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-2.C b/gcc/testsuite/g++.dg/warn/Wunused-var-2.C
new file mode 100644
index 00000000000..0b21ef11625
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-2.C
@@ -0,0 +1,104 @@
+// { dg-options "-Wunused -W" }
+
+extern void foo ();
+
+void
+f1 ()
+{
+  try
+    {
+      foo ();
+    }
+  catch (int i)
+    {
+    }
+  catch (double d)
+    {
+    }
+}
+
+void
+f2 (int x)
+{
+  int a = 0;
+  x++;
+  ++a;
+}
+
+struct A
+{
+  bool foo () const { return true; }
+};
+
+int
+f3 ()
+{
+  A a;
+  bool b = a.foo ();
+  return b;
+}
+
+struct B
+{
+  int i;
+  B (int j);
+};
+
+void
+f4 ()
+{
+  B b (6);
+}
+
+struct C
+{
+  int i;
+  C (int j) : i (j) {}
+};
+
+void
+f5 ()
+{
+  C c (6);
+}
+
+struct D
+{
+  int i;
+  D (int j) : i (j) {}
+  ~D ();
+};
+
+void
+f6 ()
+{
+  D d (6);
+}
+
+int *f7 (int s)
+{
+  return new int[s];
+}
+
+template <typename T>
+T *f8 (int s)
+{
+  return new T[s];
+}
+
+template int *f8<int> (int);
+
+void
+f9 (char *p)
+{
+  delete p;
+}
+
+template <typename T>
+void
+f10 (T *p)
+{
+  delete p;
+}
+
+template void f10<char> (char *);