From 72c9d90ce174c14f9963ac5d8471d9d3bce53964 Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Sun, 28 Sep 2008 20:06:07 +0100
Subject: [PATCH] Special unchecked nulls for d

A null in D source can be cast to a non-null type without error.
This is necessary to be able to compile D code.
---
 dmd2/cast.c       | 13 +++++++++----
 dmd2/expression.c |  1 +
 dmd2/expression.h |  1 +
 dmd2/parse.c      |  1 +
 4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/dmd2/cast.c b/dmd2/cast.c
index 8569419..bb9b3c8 100644
--- a/dmd2/cast.c
+++ b/dmd2/cast.c
@@ -389,13 +389,18 @@ MATCH NullExp::implicitConvTo(Type *t)
 	    t->ty == Taarray  || t->ty == Tmaybe ||
 	    t->ty == Tdelegate)
 	    return committed ? MATCHconvert : MATCHexact;
+	if (dUnchecked && (t->ty == Tpointer || t->ty == Tclass))
+	    return committed ? MATCHconvert : MATCHexact;
     }
 
-    /* Null can only be implicitly converted to a maybe type */
-    if (t->ty != Tmaybe)
-	return MATCHnomatch;
+    if (!dUnchecked)
+    {
+	/* In Delight, null can only be implicitly converted to a maybe type */
+	if (t->ty != Tmaybe)
+	    return MATCHnomatch;
 
-    t = t->nextOf();
+	t = t->nextOf();
+    }
 
     return Expression::implicitConvTo(t);
 }
diff --git a/dmd2/expression.c b/dmd2/expression.c
index 5cd0d2b..327b0b2 100644
--- a/dmd2/expression.c
+++ b/dmd2/expression.c
@@ -2311,6 +2311,7 @@ NullExp::NullExp(Loc loc)
 	: Expression(loc, TOKnull, sizeof(NullExp))
 {
     committed = 0;
+    dUnchecked = false;
 }
 
 Expression *NullExp::semantic(Scope *sc)
diff --git a/dmd2/expression.h b/dmd2/expression.h
index 6f0143c..c150c50 100644
--- a/dmd2/expression.h
+++ b/dmd2/expression.h
@@ -301,6 +301,7 @@ struct SuperExp : ThisExp
 struct NullExp : Expression
 {
     unsigned char committed;	// !=0 if type is committed
+    bool dUnchecked;		// can be implicitly cast to a non-null type (for D)
 
     NullExp(Loc loc);
     Expression *semantic(Scope *sc);
diff --git a/dmd2/parse.c b/dmd2/parse.c
index bd6a9a9..e63a597 100644
--- a/dmd2/parse.c
+++ b/dmd2/parse.c
@@ -4659,6 +4659,7 @@ Expression *Parser::parsePrimaryExp()
 
 	case TOKnull:
 	    e = new NullExp(loc);
+	    ((NullExp *) e)->dUnchecked = !dltSyntax;
 	    nextToken();
 	    break;
 
-- 
2.11.4.GIT