re PR c++/64527 (Constructor for empty struct not called in some situations)

Fix PR c++/64527

gcc/
	PR c++/64527
	* gimplify.c (gimplify_init_constructor): Always emit a
	side-effecting constructor.

gcc/testsuite/
	PR c++/64527
	* g++.dg/init/pr64527.C: New test.

From-SVN: r222176

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8929d06d5f9e7a0659f1791644f089e07559ce2b..bd25dd7f1f5ff8bcbc13bddd446254299c7d0125 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-04-17  Patrick Palka  <ppalka@gcc.gnu.org>
+
+       PR c++/64527
+       * gimplify.c (gimplify_init_constructor): Always emit a
+       side-effecting constructor.
+
 2015-04-17  Tom de Vries  <tom@codesourcery.com>
 
        PR tree-optimization/64950

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 0394543ef7baecb1aedae9a6c2e10f512e2d43ef..c701ef3954fc69d586aee737d5d2b4b524a1387e 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -3994,6 +3994,9 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
                                        pre_p, post_p, &preeval_data);
          }
 
+       bool ctor_has_side_effects_p
+         = TREE_SIDE_EFFECTS (TREE_OPERAND (*expr_p, 1));
+
        if (cleared)
          {
            /* Zap the CONSTRUCTOR element list, which simplifies this case.
@@ -4006,9 +4009,11 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
          }
 
        /* If we have not block cleared the object, or if there are nonzero
-          elements in the constructor, add assignments to the individual
-          scalar fields of the object.  */
-       if (!cleared || num_nonzero_elements > 0)
+          elements in the constructor, or if the constructor has side effects,
+          add assignments to the individual scalar fields of the object.  */
+       if (!cleared
+           || num_nonzero_elements > 0
+           || ctor_has_side_effects_p)
          gimplify_init_ctor_eval (object, elts, pre_p, cleared);
 
        *expr_p = NULL_TREE;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6b9b5766c6ba8f327dac37da7c19cd3763cdc8c3..1f9f1d4e03cc1cc34ca8affec0d625ec49fe25ea 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-04-17  Patrick Palka  <ppalka@gcc.gnu.org>
+
+       PR c++/64527
+       * g++.dg/init/pr64527.C: New test.
+
 2015-04-17  Tom de Vries  <tom@codesourcery.com>
            Michael Matz  <matz@suse.de>
 

diff --git a/gcc/testsuite/g++.dg/init/pr64527.C b/gcc/testsuite/g++.dg/init/pr64527.C
new file mode 100644 (file)
index 0000000..36b8214
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/pr64527.C
@@ -0,0 +1,21 @@
+// { dg-do run { target c++11 } }
+
+static int g;
+
+struct A {
+  A() { g = 1; }
+};
+
+struct accessor {
+  A a;
+  int x;
+};
+
+int
+main (void)
+{
+  (void) accessor{};
+
+  if (g != 1)
+    __builtin_abort ();
+}