[committed] d: Don't set DECL_INITIAL if initializer is 'void'.

[Iain Buclaw via Gcc-patches]

Hi,

This patch fixes a logic bug in the code-gen for variable declarations.

Declarations initialized with `= void` were being default initialized.
That is not really the intent, and misses the small optimization that
should have been gained from using void initializations.

Bootstrapped and regression tested on x86_64-linux-gnu, and committed to
mainline.

Regards
Iain.

---
gcc/d/ChangeLog:

        * decl.cc (DeclVisitor::visit (VarDeclaration *)): Don't set
        DECL_INITIAL if initializer is 'void'.

gcc/testsuite/ChangeLog:

        * gdc.dg/init1.d: New test.
---
 gcc/d/decl.cc                | 11 ++++++++---
 gcc/testsuite/gdc.dg/init1.d |  9 +++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gdc.dg/init1.d

diff --git a/gcc/d/decl.cc b/gcc/d/decl.cc
index ea6614fb714..77144fe11c8 100644
--- a/gcc/d/decl.cc
+++ b/gcc/d/decl.cc
@@ -697,13 +697,18 @@ public:
            return;
          }
 
-       if (d->_init && !d->_init->isVoidInitializer ())
+       if (d->_init)
          {
-           Expression *e = initializerToExpression (d->_init, d->type);
-           DECL_INITIAL (decl) = build_expr (e, true);
+           /* Use the explicit initializer, this includes `void`.  */
+           if (!d->_init->isVoidInitializer ())
+             {
+               Expression *e = initializerToExpression (d->_init, d->type);
+               DECL_INITIAL (decl) = build_expr (e, true);
+             }
          }
        else
          {
+           /* Use default initializer for the type.  */
            if (TypeStruct *ts = d->type->isTypeStruct ())
              DECL_INITIAL (decl) = layout_struct_initializer (ts->sym);
            else
diff --git a/gcc/testsuite/gdc.dg/init1.d b/gcc/testsuite/gdc.dg/init1.d
new file mode 100644
index 00000000000..679ad15460e
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/init1.d
@@ -0,0 +1,9 @@
+// { dg-do run { target hw } }
+// { dg-options "-fno-druntime" }
+// 'a' should not be default initialized to -1.
+static char a = void;
+
+extern (C) void main()
+{
+    assert(a == 0);
+}
-- 
2.25.1