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.

Co-Authored-By: Dodji Seketeli <dodji@redhat.com>

From-SVN: r159096

23 files changed, 1068 insertions, 228 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 686fc38..36eea3d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,40 @@
+2010-04-22  Jakub Jelinek <jakub@redhat.com>
+	    Dodji Seketeli  <dodji@redhat.com>
+
+	PR c/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.
+
 2010-05-06  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/43985
diff --git a/gcc/testsuite/c-c++-common/Wunused-var-1.c b/gcc/testsuite/c-c++-common/Wunused-var-1.c
new file mode 100644
index 0000000..ef8f6d4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wunused-var-1.c
@@ -0,0 +1,179 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+void
+f1 (void)
+{
+  int a;	/* { dg-warning "set but not used" } */
+  int b;
+  int c;
+  c = 1;
+  a = b = c;
+}
+
+void
+f2 (int x)
+{
+  int a;	/* { dg-warning "set but not used" } */
+  int b;
+  int c;	/* { dg-warning "set but not used" } */
+  c = (a = x, b = x);
+}
+
+int
+f3 (int x)
+{
+  int a;
+  return a = x;
+}
+
+int
+f4 (int x)
+{
+  int a;
+  a = x;
+  return a;
+}
+
+void
+f5 (int x)
+{
+  int a[2];	/* { dg-warning "set but not used" } */
+  int b;
+  int *c, d[2];
+  c = d;
+  b = x;
+  a[b] = 1;
+  c[b] = 1;
+}
+
+int
+f6 (int x)
+{
+  int a[2];
+  int b;
+  b = x;
+  a[b] = 1;
+  return a[b];
+}
+
+void
+f7 (int x, int *p)
+{
+  int *a[2];
+  a[x] = p;
+  a[x][x] = x;
+}
+
+struct S { int i; };
+
+void
+f8 (void)
+{
+  struct S s;	/* { dg-warning "set but not used" } */
+  s.i = 6;
+}
+
+int
+f9 (void)
+{
+  struct S s;
+  s.i = 6;
+  return s.i;
+}
+
+struct S
+f10 (void)
+{
+  struct S s;
+  s.i = 6;
+  return s;
+}
+
+extern int foo11 (int *);
+
+void
+f11 (void)
+{
+  int a[2];
+  foo11 (a);
+}
+
+void
+f12 (void)
+{
+  int a;
+  a = 1;
+  a;	/* { dg-warning "no effect" } */
+}
+
+void
+f13 (void (*x) (void))
+{
+  void (*a) (void);
+  a = x;
+  a ();
+}
+
+void
+f14 (void (*x) (void))
+{
+  void (*a) (void);	/* { dg-warning "set but not used" } */
+  a = x;
+}
+
+extern void foo15 (int *);
+
+void
+f15 (void)
+{
+  int a[10];
+  int *b = a + 2;
+  foo15 (b);
+}
+
+extern void foo16 (int **);
+
+void
+f16 (void)
+{
+  int a[10];
+  int *b[] = { a, a + 2 };
+  foo16 (b);
+}
+
+void
+f17 (int x)
+{
+  long a;	/* { dg-warning "set but not used" } */
+  int b;
+  a = b = x;
+}
+
+void
+f18 (int x)
+{
+  int a;	/* { dg-warning "set but not used" } */
+  int b;
+  a = (char) (b = x);
+}
+
+int
+f19 (int x, int y, int z)
+{
+  int a;
+  int b;
+  a = x;
+  b = y;
+  return z ? a : b;
+}
+
+int *
+f20 (int x)
+{
+  static int a[] = { 3, 4, 5, 6 };
+  static int b[] = { 4, 5, 6, 7 };
+  static int c[] = { 5, 6, 7, 8 };	/* { dg-warning "set but not used" } */
+  c[1] = 1;
+  return x ? a : b;
+}
diff --git a/gcc/testsuite/c-c++-common/Wunused-var-2.c b/gcc/testsuite/c-c++-common/Wunused-var-2.c
new file mode 100644
index 0000000..2818259
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/Wunused-var-2.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+int
+f1 (void)
+{
+  int c = ({
+    int a;
+    a = 1;
+    a; });
+  return c;
+}
+
+void
+f2 (void)
+{
+  int f;
+  f = 0;
+  __asm__ __volatile__ ("" : "+r" (f));
+}
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-3.c b/gcc/testsuite/c-c++-common/Wunused-var-3.c
index 9b1fce7..9b1fce7 100644
--- a/gcc/testsuite/gcc.dg/Wunused-var-3.c
+++ b/gcc/testsuite/c-c++-common/Wunused-var-3.c
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-7.c b/gcc/testsuite/c-c++-common/Wunused-var-4.c
index e82e708..d60c476 100644
--- a/gcc/testsuite/gcc.dg/Wunused-var-7.c
+++ b/gcc/testsuite/c-c++-common/Wunused-var-4.c
@@ -14,9 +14,9 @@ f2 (void)
   struct S { int i; } a;
   int b[1];
   a.i = 1;
-  a.i;				/* { dg-warning "with no effect" } */
+  a.i;				/* { dg-warning "no effect" } */
   b[0] = 1;
-  b[0];				/* { dg-warning "with no effect" } */
+  b[0];				/* { dg-warning "no effect" } */
 }
 
 void
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-5.c b/gcc/testsuite/c-c++-common/Wunused-var-5.c
index 747f58d..747f58d 100644
--- a/gcc/testsuite/gcc.dg/Wunused-var-5.c
+++ b/gcc/testsuite/c-c++-common/Wunused-var-5.c
diff --git a/gcc/testsuite/g++.dg/template/sfinae16.C b/gcc/testsuite/g++.dg/template/sfinae16.C
index 5ea564c..28a06d2 100644
--- a/gcc/testsuite/g++.dg/template/sfinae16.C
+++ b/gcc/testsuite/g++.dg/template/sfinae16.C
@@ -29,6 +29,6 @@ template<typename Rep>
 int main()
 {
   duration<int> d0;
-  duration<int> d1 = d0;
+  duration<int> d1 = d0;	// { dg-warning "set but not used" }
 }
 
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-7.C b/gcc/testsuite/g++.dg/warn/Wunused-7.C
index 4281bc8..6f5c23e9 100644
--- a/gcc/testsuite/g++.dg/warn/Wunused-7.C
+++ b/gcc/testsuite/g++.dg/warn/Wunused-7.C
@@ -6,7 +6,7 @@ void func()
   struct mybitfields {
     unsigned int s_field:8;
   };
-  struct mybitfields s;
+  struct mybitfields s;	// { dg-warning "set but not used" }
   s.s_field = 255;
 };
 
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-parm-1.C b/gcc/testsuite/g++.dg/warn/Wunused-parm-1.C
new file mode 100644
index 0000000..08bfaa6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-parm-1.C
@@ -0,0 +1,58 @@
+// { dg-do compile }
+// { dg-options "-Wunused -W" }
+
+long
+f1 (unsigned long long x)
+{
+  unsigned long long a = 1;
+  const union { unsigned long long l; unsigned int p[2]; } b = { x };
+  const union { unsigned long long l; unsigned int p[2]; } c = { a };
+  return b.p[0] + c.p[0];
+}
+
+int
+f2 (int x, int y)
+{
+  int a = 1;
+  int b[] = { 1, 2, x, a, 3, 4 };
+  return b[y];
+}
+
+int
+f3 (int a)	// { dg-warning "unused parameter" }
+{
+  return 0;
+}
+
+int
+f4 (int a)	// { dg-warning "set but not used" }
+{
+  a = 1;
+  return 0;
+}
+
+int
+f5 (int a)
+{
+  a = 1;
+  return a;
+}
+
+int
+f6 (int &a)
+{
+  return a;
+}
+
+void
+f7 (int &a)
+{
+  a = 1;
+}
+
+struct S
+{
+  S (int i) : j(i) {}
+  S (long i) : j(i + 1) {}
+  int j;
+};
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-parm-2.C b/gcc/testsuite/g++.dg/warn/Wunused-parm-2.C
new file mode 100644
index 0000000..d4276c0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-parm-2.C
@@ -0,0 +1,54 @@
+// { dg-do compile }
+// { dg-options "-Wunused -W" }
+
+template <int N>
+long
+f1 (unsigned long long x)
+{
+  unsigned long long a = 1;
+  const union { unsigned long long l; unsigned int p[2]; } b = { x };
+  const union { unsigned long long l; unsigned int p[2]; } c = { a };
+  return b.p[0] + c.p[0];
+}
+
+template <int N>
+int
+f2 (int x, int y)
+{
+  int a = 1;
+  int b[] = { 1, 2, x, a, 3, 4 };
+  return b[y];
+}
+
+template <int N>
+int
+f3 (int a)	// { dg-warning "unused parameter" }
+{
+  return 0;
+}
+
+template <int N>
+int
+f4 (int a)	// { dg-warning "set but not used" }
+{
+  a = 1;
+  return 0;
+}
+
+template <int N>
+int
+f5 (int a)
+{
+  a = 1;
+  return a;
+}
+
+void
+test ()
+{
+  (void) f1<0> (0);
+  (void) f2<0> (0, 0);
+  (void) f3<0> (0);
+  (void) f4<0> (0);
+  (void) f5<0> (0);
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-parm-3.C b/gcc/testsuite/g++.dg/warn/Wunused-parm-3.C
new file mode 100644
index 0000000..4d293f3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-parm-3.C
@@ -0,0 +1,69 @@
+// { dg-do compile }
+// { dg-options "-Wunused -W" }
+
+#include <stdarg.h>
+
+struct A
+{
+  long a;
+  A () : a (0) { }
+  A (long x) : a (x) { }
+  operator long () const { return a; }
+  long operator- (const A& x) const { return a - x.a; }
+};
+
+long
+fn1 (A a)
+{
+  return a - A (0);
+}
+
+struct B
+{
+  bool operator() (const int x, const int y) const throw() { return x < y; }
+};
+
+template <typename T>
+bool 
+fn2 (int x, int y, T z)
+{
+  return z (x, y);
+}
+
+bool
+fn3 (void)
+{
+  return fn2 (1, 2, B ());
+}
+
+int
+fn4 (va_list ap)
+{
+  return va_arg (ap, int);
+}
+
+template <typename T>
+T
+fn5 (va_list ap)
+{
+  return va_arg (ap, T);
+}
+
+int
+fn6 (va_list ap)
+{
+  return fn5 <int> (ap);
+}
+
+template <typename T>
+int
+fn7 (T ap)
+{
+  return va_arg (ap, int);
+}
+
+int
+fn8 (va_list ap)
+{
+  return fn7 (ap);
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-1.C b/gcc/testsuite/g++.dg/warn/Wunused-var-1.C
new file mode 100644
index 0000000..89c110b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-1.C
@@ -0,0 +1,8 @@
+// { dg-options "-Wunused" }
+template <int> struct X { static const int s = 2; };
+template <typename T> int f() { const int v = 2; return X<v+1>::s; }
+template <typename T> int g() { const int v = 2; return X<v>::s; }
+template <typename T> int h() { const int v = 2; return X<1 ? v : 0>::s; }
+template int f<int>();
+template int g<int>();
+template int h<int>();
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 0000000..0b21ef1
--- /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 *);
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-3.C b/gcc/testsuite/g++.dg/warn/Wunused-var-3.C
new file mode 100644
index 0000000..cd8931d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-3.C
@@ -0,0 +1,110 @@
+// { dg-options "-Wunused -W" }
+
+#include <typeinfo>
+#include <stdarg.h>
+
+void
+f1 (int a, ...)
+{
+  va_list ap;
+  va_start (ap, a);
+  va_end (ap);
+}
+
+int
+f2 (int a, ...)
+{
+  va_list ap;
+  va_start (ap, a);
+  int i = va_arg (ap, int);
+  va_end (ap);
+  return i;
+}
+
+struct A { int a; A (); virtual ~A (); };
+struct B : virtual A { int b; };
+
+struct B *
+f3 (struct A *a)
+{
+  return dynamic_cast <B *> (a);
+}
+
+struct A *
+f4 (struct B *a)
+{
+  return static_cast <A *> (a);
+}
+
+struct A *
+f5 (struct B *a)
+{
+  return reinterpret_cast <A *> (a);
+}
+
+struct A *
+f6 (const struct A *a)
+{
+  return const_cast <A *> (a);
+}
+
+int
+f7 (long a)
+{
+  return (int) a;
+}
+
+int
+f8 (long a)
+{
+  return int (a);
+}
+
+struct C
+{
+  operator unsigned int() { return 42; }
+};
+
+unsigned int
+f9 ()
+{
+  C u;
+  return u;
+}
+
+struct D
+{
+  operator int & ();
+  operator const int & () const;
+};
+
+void foo (int &);
+void foo (const int &);
+
+void
+f10 ()
+{
+  const D x = D ();
+  foo (x);
+}
+
+int
+f11 (int a)
+{
+  return typeid (a) == typeid (int);
+}
+
+struct E
+{
+  int e () {return 0;}
+};
+
+template <typename T>
+int
+f12 (E a)
+{
+  __decltype (a.e()) i;
+  return i;
+}
+
+template <> int f12<int> (E);
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-4.C b/gcc/testsuite/g++.dg/warn/Wunused-var-4.C
new file mode 100644
index 0000000..11ed7af
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-4.C
@@ -0,0 +1,50 @@
+/* { dg-do compile } */
+/* { dg-options "-Wunused" } */
+
+struct S { int e; };
+
+int
+f1 (void)
+{
+  int a;
+  int b;
+  int c;
+  int d;
+  S s;
+  a = 1;
+  b = 2;
+  c = 3;
+  d = 4;
+  s.e = 5;
+  __typeof (c) e;	// { dg-warning "set but not used" }
+  __decltype (d) f;	// { dg-warning "set but not used" }
+  __decltype (s.e) g;	// { dg-warning "set but not used" }
+  e = 1;
+  f = 1;
+  g = 1;
+  return sizeof (a) + __alignof__ (b);
+}
+
+template <int N>
+int f2 (void)
+{
+  int a;
+  int b;
+  int c;
+  int d;
+  a = 1;
+  b = 2;
+  c = 3;
+  d = 4;
+  __typeof (c) e;	// { dg-warning "set but not used" }
+  __decltype (d) f;	// { dg-warning "set but not used" }
+  e = 1;
+  f = 1;
+  return sizeof (a) + __alignof__ (b);
+}
+
+void
+test (void)
+{
+  (void) f2<0> ();
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-5.C b/gcc/testsuite/g++.dg/warn/Wunused-var-5.C
new file mode 100644
index 0000000..7fcaa95
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-5.C
@@ -0,0 +1,227 @@
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+template <int N>
+void
+f1 (void)
+{
+  int a;	// { dg-warning "set but not used" }
+  int b;
+  int c;
+  c = 1;
+  a = b = c;
+}
+
+template <int N>
+void
+f2 (int x)
+{
+  int a;	// { dg-warning "set but not used" }
+  int b;
+  int c;	// { dg-warning "set but not used" }
+  c = (a = x, b = x);
+}
+
+template <int N>
+int
+f3 (int x)
+{
+  int a;
+  return a = x;
+}
+
+template <int N>
+int
+f4 (int x)
+{
+  int a;
+  a = x;
+  return a;
+}
+
+template <int N>
+void
+f5 (int x)
+{
+  int a[2];	// { dg-warning "set but not used" }
+  int b;
+  int *c, d[2];
+  c = d;
+  b = x;
+  a[b] = 1;
+  c[b] = 1;
+}
+
+template <int N>
+int
+f6 (int x)
+{
+  int a[2];
+  int b;
+  b = x;
+  a[b] = 1;
+  return a[b];
+}
+
+template <int N>
+void
+f7 (int x, int *p)
+{
+  int *a[2];
+  a[x] = p;
+  a[x][x] = x;
+}
+
+struct S { int i; };
+
+template <int N>
+void
+f8 (void)
+{
+  struct S s;	// { dg-warning "set but not used" }
+  s.i = 6;
+}
+
+template <int N>
+int
+f9 (void)
+{
+  struct S s;
+  s.i = 6;
+  return s.i;
+}
+
+template <int N>
+struct S
+f10 (void)
+{
+  struct S s;
+  s.i = 6;
+  return s;
+}
+
+extern int foo11 (int *);
+
+template <int N>
+void
+f11 (void)
+{
+  int a[2];
+  foo11 (a);
+}
+
+template <int N>
+void
+f12 (void)
+{
+  int a;
+  a = 1;
+  a;	// { dg-warning "statement has no effect" }
+}
+
+template <int N>
+void
+f13 (void (*x) (void))
+{
+  void (*a) (void);
+  a = x;
+  a ();
+}
+
+template <int N>
+void
+f14 (void (*x) (void))
+{
+  void (*a) (void);	// { dg-warning "set but not used" }
+  a = x;
+}
+
+extern void foo15 (int *);
+
+template <int N>
+void
+f15 (void)
+{
+  int a[10];
+  int *b = a + 2;
+  foo15 (b);
+}
+
+extern void foo16 (int **);
+
+template <int N>
+void
+f16 (void)
+{
+  int a[10];
+  int *b[] = { a, a + 2 };
+  foo16 (b);
+}
+
+template <int N>
+void
+f17 (int x)
+{
+  long a;	// { dg-warning "set but not used" }
+  int b;
+  a = b = x;
+}
+
+template <int N>
+void
+f18 (int x)
+{
+  int a;	// { dg-warning "set but not used" }
+  int b;
+  a = (char) (b = x);
+}
+
+template <int N>
+int
+f19 (int x, int y, int z)
+{
+  int a;
+  int b;
+  a = x;
+  b = y;
+  return z ? a : b;
+}
+
+template <int N>
+int *
+f20 (int x)
+{
+  static int a[] = { 3, 4, 5, 6 };
+  static int b[] = { 4, 5, 6, 7 };
+  static int c[] = { 5, 6, 7, 8 };	// { dg-warning "set but not used" }
+  c[1] = 1;
+  return x ? a : b;
+}
+
+S s;
+
+void
+test ()
+{
+  int i = 0;
+  f1<0> ();
+  f2<0> (0);
+  (void) f3<0> (0);
+  (void) f4<0> (0);
+  f5<0> (0);
+  (void) f6<0> (0);
+  f7<0> (0, &i);
+  f8<0> ();
+  (void) f9<0> ();
+  s = f10<0> ();
+  f11<0> ();
+  f12<0> ();
+  f13<0> (f1<0>);
+  f14<0> (f1<0>);
+  f15<0> ();
+  f16<0> ();
+  f17<0> (0);
+  f18<0> (0);
+  (void) f19<0> (0, 0, 0);
+  (void) f20<0> (0);
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-6.C b/gcc/testsuite/g++.dg/warn/Wunused-var-6.C
new file mode 100644
index 0000000..0fb8e5c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-6.C
@@ -0,0 +1,29 @@
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+template <int N>
+int
+f1 (void)
+{
+  int c = ({
+    int a;
+    a = 1;
+    a; });
+  return c;
+}
+
+template <int N>
+void
+f2 (void)
+{
+  int f;
+  f = 0;
+  __asm__ __volatile__ ("" : "+r" (f));
+}
+
+void
+test ()
+{
+  (void) f1<0> ();
+  f2<0> ();
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-7.C b/gcc/testsuite/g++.dg/warn/Wunused-var-7.C
new file mode 100644
index 0000000..cf1b605
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-7.C
@@ -0,0 +1,48 @@
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+template <int N>
+void
+f1 (void)
+{
+  _Complex int a;	// { dg-warning "set but not used" }
+  _Complex double b;	// { dg-warning "set but not used" }
+  __real__ a = 1;
+  __imag__ a = 2;
+  __real__ b = 3.0;
+  __imag__ b = 4.0;
+}
+
+template <int N>
+int
+f2 (void)
+{
+  _Complex int a;
+  _Complex double b;
+  __real__ a = 1;
+  __imag__ a = 2;
+  __real__ b = 3.0;
+  __imag__ b = 4.0;
+  return __real__ a + __imag__ b;
+}
+
+template <int N>
+_Complex double
+f3 (void)
+{
+  _Complex int a;
+  _Complex double b;
+  __real__ a = 1;
+  __imag__ a = 2;
+  __real__ b = 3.0;
+  __imag__ b = 4.0;
+  return a + b;
+}
+
+void
+test ()
+{
+  f1<0> ();
+  (void) f2<0> ();
+  (void) f3<0> ();
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wunused-var-8.C b/gcc/testsuite/g++.dg/warn/Wunused-var-8.C
new file mode 100644
index 0000000..69fc6fb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wunused-var-8.C
@@ -0,0 +1,46 @@
+// { dg-do compile }
+// { dg-options "-Wunused" }
+
+template <int N>
+void
+f1 (void)
+{
+  extern int extvari;
+  extvari = 1;
+}
+
+int extvarj;
+
+template <int N>
+void
+f2 (void)
+{
+  extern int extvarj;
+  extvarj = 1;
+}
+
+static int extvark;
+
+template <int N>
+void
+f3 (void)
+{
+  extern int extvark;
+  extvark = 1;
+}
+
+template <int N>
+int
+f4 (void)
+{
+  return extvark;
+}
+
+void
+test ()
+{
+  f1<0> ();
+  f2<0> ();
+  f3<0> ();
+  (void) f4<0> ();
+}
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-1.c b/gcc/testsuite/gcc.dg/Wunused-var-1.c
index bee34d8..d60dd70 100644
--- a/gcc/testsuite/gcc.dg/Wunused-var-1.c
+++ b/gcc/testsuite/gcc.dg/Wunused-var-1.c
@@ -1,179 +1,26 @@
 /* { dg-do compile } */
 /* { dg-options "-Wunused" } */
 
-void
-f1 (void)
-{
-  int a;	/* { dg-warning "set but not used" } */
-  int b;
-  int c;
-  c = 1;
-  a = b = c;
-}
-
-void
-f2 (int x)
-{
-  int a;	/* { dg-warning "set but not used" } */
-  int b;
-  int c;	/* { dg-warning "set but not used" } */
-  c = (a = x, b = x);
-}
-
 int
-f3 (int x)
-{
-  int a;
-  return a = x;
-}
-
-int
-f4 (int x)
-{
-  int a;
-  a = x;
-  return a;
-}
-
-void
-f5 (int x)
-{
-  int a[2];	/* { dg-warning "set but not used" } */
-  int b;
-  int *c, d[2];
-  c = d;
-  b = x;
-  a[b] = 1;
-  c[b] = 1;
-}
-
-int
-f6 (int x)
-{
-  int a[2];
-  int b;
-  b = x;
-  a[b] = 1;
-  return a[b];
-}
-
-void
-f7 (int x, int *p)
-{
-  int *a[2];
-  a[x] = p;
-  a[x][x] = x;
-}
-
-struct S { int i; };
-
-void
-f8 (void)
-{
-  struct S s;	/* { dg-warning "set but not used" } */
-  s.i = 6;
-}
-
-int
-f9 (void)
-{
-  struct S s;
-  s.i = 6;
-  return s.i;
-}
-
-struct S
-f10 (void)
-{
-  struct S s;
-  s.i = 6;
-  return s;
-}
-
-extern int foo11 (int *);
-
-void
-f11 (void)
-{
-  int a[2];
-  foo11 (a);
-}
-
-void
-f12 (void)
+f1 (void)
 {
   int a;
+  int foo (void)
+  {
+    return a;
+  }
   a = 1;
-  a;	/* { dg-warning "statement with no effect" } */
+  return foo ();
 }
 
 void
-f13 (void (*x) (void))
-{
-  void (*a) (void);
-  a = x;
-  a ();
-}
-
-void
-f14 (void (*x) (void))
-{
-  void (*a) (void);	/* { dg-warning "set but not used" } */
-  a = x;
-}
-
-extern void foo15 (int *);
-
-void
-f15 (void)
-{
-  int a[10];
-  int *b = a + 2;
-  foo15 (b);
-}
-
-extern void foo16 (int **);
-
-void
-f16 (void)
-{
-  int a[10];
-  int *b[] = { a, a + 2 };
-  foo16 (b);
-}
-
-void
-f17 (int x)
-{
-  long a;	/* { dg-warning "set but not used" } */
-  int b;
-  a = b = x;
-}
-
-void
-f18 (int x)
+f2 (void)
 {
   int a;	/* { dg-warning "set but not used" } */
-  int b;
-  a = (char) (b = x);
-}
-
-int
-f19 (int x, int y, int z)
-{
-  int a;
-  int b;
-  a = x;
-  b = y;
-  return z ? a : b;
-}
-
-int *
-f20 (int x)
-{
-  static int a[] = { 3, 4, 5, 6 };
-  static int b[] = { 4, 5, 6, 7 };
-  static int c[] = { 5, 6, 7, 8 };	/* { dg-warning "set but not used" } */
-  c[1] = 1;
-  return x ? a : b;
+  void foo (void)
+  {
+    a = 2;
+  }
+  a = 1;
+  foo ();
 }
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-2.c b/gcc/testsuite/gcc.dg/Wunused-var-2.c
index 2818259..b5a22f8 100644
--- a/gcc/testsuite/gcc.dg/Wunused-var-2.c
+++ b/gcc/testsuite/gcc.dg/Wunused-var-2.c
@@ -4,17 +4,16 @@
 int
 f1 (void)
 {
-  int c = ({
-    int a;
-    a = 1;
-    a; });
-  return c;
-}
-
-void
-f2 (void)
-{
-  int f;
-  f = 0;
-  __asm__ __volatile__ ("" : "+r" (f));
+  int a;
+  int b;
+  int c;
+  int d;
+  int e;
+  a = 1;
+  b = 2;
+  c = 3;
+  d = 4;
+  e = 5;
+  return sizeof (a) + ((__typeof (b)) 1) + __alignof__ (c)
+         + __builtin_choose_expr (1, d, e);
 }
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-4.c b/gcc/testsuite/gcc.dg/Wunused-var-4.c
deleted file mode 100644
index d60dd70..0000000
--- a/gcc/testsuite/gcc.dg/Wunused-var-4.c
+++ /dev/null
@@ -1,26 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-Wunused" } */
-
-int
-f1 (void)
-{
-  int a;
-  int foo (void)
-  {
-    return a;
-  }
-  a = 1;
-  return foo ();
-}
-
-void
-f2 (void)
-{
-  int a;	/* { dg-warning "set but not used" } */
-  void foo (void)
-  {
-    a = 2;
-  }
-  a = 1;
-  foo ();
-}
diff --git a/gcc/testsuite/gcc.dg/Wunused-var-6.c b/gcc/testsuite/gcc.dg/Wunused-var-6.c
deleted file mode 100644
index b5a22f8..0000000
--- a/gcc/testsuite/gcc.dg/Wunused-var-6.c
+++ /dev/null
@@ -1,19 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-Wunused" } */
-
-int
-f1 (void)
-{
-  int a;
-  int b;
-  int c;
-  int d;
-  int e;
-  a = 1;
-  b = 2;
-  c = 3;
-  d = 4;
-  e = 5;
-  return sizeof (a) + ((__typeof (b)) 1) + __alignof__ (c)
-         + __builtin_choose_expr (1, d, e);
-}