Merge pull request #3204 from 9rnsr/fix11824

[REG2.065a] Issue 11824 - A stack variable escaping problem in CTFE Phobos code
dlang · Feb 7, 2014 · cbc100a · cbc100a
2 parents 231e27f + dc828cc
commit cbc100a
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Showing 3 changed files with 108 additions and 5 deletions.
diff --git a/src/interpret.c b/src/interpret.c
@@ -1184,15 +1184,29 @@ bool stopPointersEscaping(Loc loc, Expression *e)
 {
     if (!e->type->hasPointers())
         return true;
-    if ( isPointer(e->type) )
+    if (isPointer(e->type))
     {
         Expression *x = e;
         if (e->op == TOKaddress)
             x = ((AddrExp *)e)->e1;
-        if (x->op == TOKvar && ((VarExp *)x)->var->isVarDeclaration() &&
-            ctfeStack.isInCurrentFrame( ((VarExp *)x)->var->isVarDeclaration() ) )
-        {   error(loc, "returning a pointer to a local stack variable");
-            return false;
+        VarDeclaration *v;
+        while (x->op == TOKvar &&
+            (v = ((VarExp *)x)->var->isVarDeclaration()) != NULL)
+        {
+            if (v->storage_class & STCref)
+            {
+                x = v->getValue();
+                if (e->op == TOKaddress)
+                    ((AddrExp *)e)->e1 = x;
+                continue;
+            }
+            if (ctfeStack.isInCurrentFrame(v))
+            {
+                error(loc, "returning a pointer to a local stack variable");
+                return false;
+            }
+            else
+                break;
         }
         // TODO: If it is a TOKdotvar or TOKindex, we should check that it is not
         // pointing to a local struct or static array.

diff --git a/test/compilable/interpret3.d b/test/compilable/interpret3.d
@@ -3935,6 +3935,23 @@ static assert(!is(typeof(compiles!(test7876(0)))));
 static assert( is(typeof(compiles!(test7876(11)))));
 static assert(!is(typeof(compiles!(test7876(10)))));
 
+/**************************************************
+    11824
+**************************************************/
+
+int f11824(T)()
+{
+    T[] arr = new T[](1);
+    T* getAddr(ref T a)
+    {
+        return &a;
+    }
+    getAddr(arr[0]);
+    return 1;
+}
+static assert(f11824!int());        // OK
+static assert(f11824!(int[])());    // OK <- NG
+
 /**************************************************
     6817 if converted to &&, only with -inline
 **************************************************/

diff --git a/test/compilable/test11824.d b/test/compilable/test11824.d
@@ -0,0 +1,72 @@
+// REQUIRED_ARGS: -o-
+// PERMUTE_ARGS:
+
+struct Take(R)
+{
+    public R source;
+    private size_t _maxAvailable;
+
+    alias R Source;
+
+    @property bool empty()
+    {
+        return _maxAvailable == 0 || source.empty;
+    }
+
+    @property auto ref front()
+    {
+        return source.front;
+    }
+
+    void popFront()
+    {
+        source.popFront();
+        --_maxAvailable;
+    }
+
+    @property size_t length() const
+    {
+        return _maxAvailable;
+    }
+}
+
+struct Repeat(T)
+{
+    private T _value;
+
+    enum bool empty = false;
+    @property inout(T) front() inout { return _value; }
+    void popFront() {}
+}
+
+Take!(Repeat!T) repeat(T)(T value, size_t n)
+{
+    return typeof(return)(Repeat!T(value), n);
+}
+
+auto array(Range)(Range r)
+{
+    alias E = typeof(r.front);
+    //static if (hasLength!Range)
+    {
+        if (r.length == 0)
+            return null;
+
+        auto result = new E[](r.length);
+
+        size_t i;
+        static auto trustedGetAddr(T)(ref T t) @trusted nothrow pure
+        {
+            return &t;
+        }
+        foreach (e; r)
+        {
+            *trustedGetAddr(result[i]) = e;
+            ++i;
+        }
+        return cast(E[])result;
+    }
+}
+
+enum r = [1].repeat(1).array;
+static assert(r == [[1]]);