diff mbox series

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

Message ID 20200625153828.2304469-2-ibuclaw@gdcproject.org
State New
Headers show
Series [committed] d: Don't set DECL_INITIAL if initializer is 'void'. | expand

Commit Message

Iain Buclaw June 25, 2020, 3:38 p.m. UTC 
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 mbox series

Patch

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);
+}