re PR c++/78550 (bit field and std::initializer_list)

	PR c++/78550
	* convert.c (convert_to_integer_1): Maybe fold conversions to
	integral types with fewer bits than its mode.

	testsuite/
	PR c++/78550
	* g++.dg/cpp1y/pr78550.C: New.

From-SVN: r243479

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index eaada9bc71a140379e6c9098d5f68320f0541283..d2e5f478cc42c76adf2e7436fe36514bc595a7a0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-12-09  Nathan Sidwell  <nathan@acm.org>
+
+       PR C++/78550
+       * convert.c (convert_to_integer_1): Maybe fold conversions to
+       integral types with fewer bits than its mode.
+
 2016-12-09  Martin Liska  <mliska@suse.cz>
 
        * tree-pretty-print.c (pretty_print_string): Escape non-printable
@@ -67,9 +73,8 @@
 
 2016-12-08  Dmitry Vyukov  <dvyukov@google.com>
 
-       * opts.c (finish_options): Enable
-       -fsanitize-address-use-after-scope only if -fsanitize=address is enabled
-       (not -fsanitize=kernel-address).
+       * opts.c (finish_options): Enable -fsanitize-address-use-after-scope
+       only if -fsanitize=address is enabled (not -fsanitize=kernel-address).
        * doc/invoke.texi (-fsanitize=kernel-address):
        Don't say that it enables -fsanitize-address-use-after-scope.
 

diff --git a/gcc/convert.c b/gcc/convert.c
index 8f18ee4d2477e88d926c2eecaed6e09e3c6f3fca..54b0a5d8327823a3939e13d7a5a73a7a715a45dd 100644 (file)
--- a/gcc/convert.c
+++ b/gcc/convert.c
@@ -646,10 +646,11 @@ convert_to_integer_1 (tree type, tree expr, bool dofold)
         to TYPE.  */
       else if (TREE_CODE (type) == ENUMERAL_TYPE
               || outprec != GET_MODE_PRECISION (TYPE_MODE (type)))
-       return build1 (NOP_EXPR, type,
-                      convert (lang_hooks.types.type_for_mode
-                               (TYPE_MODE (type), TYPE_UNSIGNED (type)),
-                               expr));
+       {
+         expr = convert (lang_hooks.types.type_for_mode
+                         (TYPE_MODE (type), TYPE_UNSIGNED (type)), expr);
+         return maybe_fold_build1_loc (dofold, loc, NOP_EXPR, type, expr);
+       }
 
       /* Here detect when we can distribute the truncation down past some
         arithmetic.  For example, if adding two longs and converting to an

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 843ee9f928dd53849b57cb6cd637251625965a47..2f15e89d4563787d9cff2ad420793232e0b38cd0 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-09  Nathan Sidwell  <nathan@acm.org>
+
+       PR c++/78550
+       * g++.dg/cpp1y/pr78550.C: New.
+
 2016-12-09  Paul Thomas  <pault@gcc.gnu.org>
 
        PR fortran/44265

diff --git a/gcc/testsuite/g++.dg/cpp1y/pr78550.C b/gcc/testsuite/g++.dg/cpp1y/pr78550.C
new file mode 100644 (file)
index 0000000..95596b1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/pr78550.C
@@ -0,0 +1,22 @@
+// { dg-do compile { target c++14 } }
+
+// PR 78550 ICE with initializer_list and bitfield member
+
+namespace std
+{
+  template <class T>
+  struct initializer_list
+    {
+      const T *a;
+      __SIZE_TYPE__ b;
+      constexpr initializer_list (const T *x, __SIZE_TYPE__ y) : a(x), b(y) { }
+    };
+}
+template <typename T>
+struct A {
+  A (std::initializer_list<T>);
+};
+struct B {
+  int k : 1;
+};
+A<B> a{{0}};