PR c++/84338 - wrong variadic sizeof.

	* pt.c (argument_pack_select_arg): Like the macro, but look through
	a pack expansion.
	(tsubst, tsubst_copy, dependent_template_arg_p): Use it.
	(extract_fnparm_pack): Do make_pack_expansion.
	(extract_locals_r): Do strip a pack expansion.
	* cp-tree.h (ARGUMENT_PACK_SELECT_ARG): Remove.

From-SVN: r257626

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index c2b19d8eb593f92c5d4aecc56028f2c197ccfcb5..677392c31fc09c5b73a18d6426c107f7c006de2a 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,13 @@
+2018-02-13  Jason Merrill  <jason@redhat.com>
+
+       PR c++/84338 - wrong variadic sizeof.
+       * pt.c (argument_pack_select_arg): Like the macro, but look through
+       a pack expansion.
+       (tsubst, tsubst_copy, dependent_template_arg_p): Use it.
+       (extract_fnparm_pack): Do make_pack_expansion.
+       (extract_locals_r): Do strip a pack expansion.
+       * cp-tree.h (ARGUMENT_PACK_SELECT_ARG): Remove.
+
 2018-02-12  Jakub Jelinek  <jakub@redhat.com>
 
        PR c++/84341

diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index a6c75aed33d692d2bc1c001c2c42aef02816555c..9a9e9f0bbcb0c5033674d1cee95fd3adf3dcf957 100644 (file)
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3558,12 +3558,6 @@ extern void decl_shadowed_for_var_insert (tree, tree);
 #define ARGUMENT_PACK_SELECT_INDEX(NODE)                               \
   (((struct tree_argument_pack_select *)ARGUMENT_PACK_SELECT_CHECK (NODE))->index)
   
-/* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
-   ARGUMENT_PACK_SELECT represents. */
-#define ARGUMENT_PACK_SELECT_ARG(NODE)                                 \
-  TREE_VEC_ELT (ARGUMENT_PACK_ARGS (ARGUMENT_PACK_SELECT_FROM_PACK (NODE)), \
-               ARGUMENT_PACK_SELECT_INDEX (NODE))
-
 #define FOLD_EXPR_CHECK(NODE)                                          \
   TREE_CHECK4 (NODE, UNARY_LEFT_FOLD_EXPR, UNARY_RIGHT_FOLD_EXPR,      \
               BINARY_LEFT_FOLD_EXPR, BINARY_RIGHT_FOLD_EXPR)

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index b58c60f0dcb0e563b6304d5e44527382ca5e95dd..a83b7073d20f6d79ef2209f2cdc870fc25c50b1f 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3394,6 +3394,34 @@ get_template_argument_pack_elems (const_tree t)
   return ARGUMENT_PACK_ARGS (t);
 }
 
+/* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
+   ARGUMENT_PACK_SELECT represents. */
+
+static tree
+argument_pack_select_arg (tree t)
+{
+  tree args = ARGUMENT_PACK_ARGS (ARGUMENT_PACK_SELECT_FROM_PACK (t));
+  tree arg = TREE_VEC_ELT (args, ARGUMENT_PACK_SELECT_INDEX (t));
+
+  /* If the selected argument is an expansion E, that most likely means we were
+     called from gen_elem_of_pack_expansion_instantiation during the
+     substituting of an argument pack (of which the Ith element is a pack
+     expansion, where I is ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
+     In this case, the Ith element resulting from this substituting is going to
+     be a pack expansion, which pattern is the pattern of E.  Let's return the
+     pattern of E, and gen_elem_of_pack_expansion_instantiation will build the
+     resulting pack expansion from it.  */
+  if (PACK_EXPANSION_P (arg))
+    {
+      /* Make sure we aren't throwing away arg info.  */
+      gcc_assert (!PACK_EXPANSION_EXTRA_ARGS (arg));
+      arg = PACK_EXPANSION_PATTERN (arg);
+    }
+
+  return arg;
+}
+
+
 /* True iff FN is a function representing a built-in variadic parameter
    pack.  */
 
@@ -10933,7 +10961,12 @@ extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
   parmvec = make_tree_vec (len);
   spec_parm = *spec_p;
   for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
-    TREE_VEC_ELT (parmvec, i) = spec_parm;
+    {
+      tree elt = spec_parm;
+      if (DECL_PACK_P (elt))
+       elt = make_pack_expansion (elt);
+      TREE_VEC_ELT (parmvec, i) = elt;
+    }
 
   /* Build the argument packs.  */
   SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
@@ -11388,7 +11421,8 @@ extract_locals_r (tree *tp, int */*walk_subtrees*/, void *data)
          /* Pull out the actual PARM_DECL for the partial instantiation.  */
          tree args = ARGUMENT_PACK_ARGS (spec);
          gcc_assert (TREE_VEC_LENGTH (args) == 1);
-         spec = TREE_VEC_ELT (args, 0);
+         tree arg = TREE_VEC_ELT (args, 0);
+         spec = PACK_EXPANSION_PATTERN (arg);
        }
       *extra = tree_cons (*tp, spec, *extra);
     }
@@ -13747,29 +13781,9 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
          {
            arg = TMPL_ARG (args, level, idx);
 
+           /* See through ARGUMENT_PACK_SELECT arguments. */
            if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
-             {
-               /* See through ARGUMENT_PACK_SELECT arguments. */
-               arg = ARGUMENT_PACK_SELECT_ARG (arg);
-               /* If the selected argument is an expansion E, that most
-                  likely means we were called from
-                  gen_elem_of_pack_expansion_instantiation during the
-                  substituting of pack an argument pack (which Ith
-                  element is a pack expansion, where I is
-                  ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
-                  In this case, the Ith element resulting from this
-                  substituting is going to be a pack expansion, which
-                  pattern is the pattern of E.  Let's return the
-                  pattern of E, and
-                  gen_elem_of_pack_expansion_instantiation will
-                  build the resulting pack expansion from it.  */
-               if (PACK_EXPANSION_P (arg))
-                 {
-                   /* Make sure we aren't throwing away arg info.  */
-                   gcc_assert (!PACK_EXPANSION_EXTRA_ARGS (arg));
-                   arg = PACK_EXPANSION_PATTERN (arg);
-                 }
-             }
+             arg = argument_pack_select_arg (arg);
          }
 
        if (arg == error_mark_node)
@@ -14734,7 +14748,7 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
        }
       
       if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
-       r = ARGUMENT_PACK_SELECT_ARG (r);
+       r = argument_pack_select_arg (r);
       if (!mark_used (r, complain) && !(complain & tf_error))
        return error_mark_node;
       return r;
@@ -14866,7 +14880,7 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
                register_local_specialization (r, t);
            }
          if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
-           r = ARGUMENT_PACK_SELECT_ARG (r);
+           r = argument_pack_select_arg (r);
        }
       else
        r = t;
@@ -24701,7 +24715,7 @@ dependent_template_arg_p (tree arg)
     return true;
 
   if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
-    arg = ARGUMENT_PACK_SELECT_ARG (arg);
+    arg = argument_pack_select_arg (arg);
 
   if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
     return true;

diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic13.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic13.C
new file mode 100644 (file)
index 0000000..92fd34c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic13.C
@@ -0,0 +1,15 @@
+// PR c++/84338
+// { dg-do compile { target c++14 } }
+
+template < typename ... T >
+auto f(T ... i){
+    [](auto ... i){
+        // // wrongly true in current trunk
+        // static_assert(sizeof...(i) == 1, "");
+        static_assert(sizeof...(i) == 2, "");
+    }(i ...);
+}
+
+int main(){
+    f(0, 1);
+}