Implement -Wswitch-fallthrough: java

[Marek Polacek]

2016-07-11  Marek Polacek  <polacek@redhat.com>

	PR c/7652
	* expr.c (java_truthvalue_conversion): Add gcc_fallthrough.
	(type_assertion_hasher::hash): Likewise.
	* jcf-dump.c (print_constant): Likewise.
	* jcf-io.c (verify_constant_pool): Likewise.
	* typeck.c (promote_type): Likewise.

diff --git gcc/gcc/java/expr.c gcc/gcc/java/expr.c
index 2b856e5..d824b6c 100644
--- gcc/gcc/java/expr.c
+++ gcc/gcc/java/expr.c
@@ -192,6 +192,7 @@ java_truthvalue_conversion (tree expr)
           >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
         return java_truthvalue_conversion (TREE_OPERAND (expr, 0));
       /* fall through to default */
+      gcc_fallthrough ();
 
     default:
       return fold_build2 (NE_EXPR, boolean_type_node,
@@ -410,11 +411,13 @@ type_assertion_hasher::hash (type_assertion *k_p)
       hash = iterative_hash (&TYPE_UID (k_p->op2), sizeof TYPE_UID (k_p->op2),
 			     hash);
       /* Fall through.  */
+      gcc_fallthrough ();
 
     case JV_ASSERT_IS_INSTANTIABLE:
       hash = iterative_hash (&TYPE_UID (k_p->op1), sizeof TYPE_UID (k_p->op1),
 			     hash);
       /* Fall through.  */
+      gcc_fallthrough ();
 
     case JV_ASSERT_END_OF_TABLE:
       break;
diff --git gcc/gcc/java/jcf-dump.c gcc/gcc/java/jcf-dump.c
index 1331b55..d8733ed 100644
--- gcc/gcc/java/jcf-dump.c
+++ gcc/gcc/java/jcf-dump.c
@@ -926,6 +926,8 @@ print_constant (FILE *out, JCF *jcf, int index, int verbosity)
 	  if (verbosity > 0)
 	    fprintf (out, "Fieldref: %ld=", (long) JPOOL_USHORT2 (jcf, index));
 	  print_constant (out, jcf, JPOOL_USHORT2 (jcf, index), 0);
+	  /* XXX Really fallthru?  */
+	  gcc_fallthrough ();
 	case 5:
 	case 6:
 	case 7:
diff --git gcc/gcc/java/jcf-io.c gcc/gcc/java/jcf-io.c
index a560db7..91d9048 100644
--- gcc/gcc/java/jcf-io.c
+++ gcc/gcc/java/jcf-io.c
@@ -472,6 +472,7 @@ verify_constant_pool (JCF *jcf)
 	      || JPOOL_TAG (jcf, n) != CONSTANT_Utf8)
 	    return i;
 	  /* ... fall through ... */
+	  gcc_fallthrough ();
 	case CONSTANT_Class:
 	case CONSTANT_String:
 	  n = JPOOL_USHORT1 (jcf, i);
diff --git gcc/gcc/java/typeck.c gcc/gcc/java/typeck.c
index d2e3db6..f7c5da4 100644
--- gcc/gcc/java/typeck.c
+++ gcc/gcc/java/typeck.c
@@ -332,6 +332,7 @@ promote_type (tree type)
     case INTEGER_TYPE:
       if (type == char_type_node)
 	return promoted_char_type_node;
+      gcc_fallthrough ();
     handle_int:
       if (TYPE_PRECISION (type) < TYPE_PRECISION (int_type_node))
 	{
@@ -342,6 +343,7 @@ promote_type (tree type)
 	  return int_type_node;
 	}
       /* ... else fall through ... */
+      gcc_fallthrough ();
     default:
       return type;
     }