Fix Issue 4733 - Possible bugs caused by dynamic arrays in boolean ev…

…aluation context Turn it into a warning
dlang · Feb 2, 2015 · 727233c · 727233c
1 parent 37e6395
commit 727233c
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Showing 2 changed files with 33 additions and 0 deletions.
diff --git a/src/expression.c b/src/expression.c
@@ -2662,6 +2662,11 @@ Expression *Expression::checkToBoolean(Scope *sc)
             error("expression %s of type %s does not have a boolean value", toChars(), t->toChars());
         return new ErrorExp();
     }
+
+    if (tb->ty == Tarray)
+        warning("implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: %s !is null, %s.length, or %s.ptr instead",
+            toChars(), toChars(), toChars());
+
     return e;
 }
 

diff --git a/test/fail_compilation/warn4733.d b/test/fail_compilation/warn4733.d
@@ -0,0 +1,28 @@
+/*
+REQUIRED_ARGS: -w
+PERMUTE_ARGS:
+TEST_OUTPUT:
+---
+fail_compilation/warn4733.d(20): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(21): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(22): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(23): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(24): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(25): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(26): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+fail_compilation/warn4733.d(27): Warning: implicit conversion of dynamic arrays to bool can be ambiguous and will be deprecated. Use one of: arr !is null, arr.length, or arr.ptr instead
+---
+*/
+
+void main()
+{
+    int[] arr;
+    assert(arr);
+    assert(!arr);
+    assert(arr || 0);
+    assert(arr && 1);
+    assert(arr ? true : false);
+    do {} while(arr);
+    for (; arr;) {}
+    if (arr) {}
+}