fix Issue 14862 - Constructor of overlapped struct does not initializ…

…e correctly global variables

src/aggregate.d

@@ -355,57 +355,6 @@ public:
         return type;
     }
 
-    /****************************************
-     * If field[indx] is not part of a union, return indx.
-     * Otherwise, return the lowest field index of the union.
-     */
-    final int firstFieldInUnion(int indx)
-    {
-        if (isUnionDeclaration())
-            return 0;
-        VarDeclaration vd = fields[indx];
-        int firstNonZero = indx; // first index in the union with non-zero size
-        for (;;)
-        {
-            if (indx == 0)
-                return firstNonZero;
-            VarDeclaration v = fields[indx - 1];
-            if (v.offset != vd.offset)
-                return firstNonZero;
-            --indx;
-            /* If it is a zero-length field, it's ambiguous: we don't know if it is
-             * in the union unless we find an earlier non-zero sized field with the
-             * same offset.
-             */
-            if (v.size(loc) != 0)
-                firstNonZero = indx;
-        }
-    }
-
-    /****************************************
-     * Count the number of fields starting at firstIndex which are part of the
-     * same union as field[firstIndex]. If not a union, return 1.
-     */
-    final int numFieldsInUnion(int firstIndex)
-    {
-        VarDeclaration vd = fields[firstIndex];
-        /* If it is a zero-length field, AND we can't find an earlier non-zero
-         * sized field with the same offset, we assume it's not part of a union.
-         */
-        if (vd.size(loc) == 0 && !isUnionDeclaration() && firstFieldInUnion(firstIndex) == firstIndex)
-            return 1;
-        int count = 1;
-        for (size_t i = firstIndex + 1; i < fields.dim; ++i)
-        {
-            VarDeclaration v = fields[i];
-            // If offsets are different, they are not in the same union
-            if (v.offset != vd.offset)
-                break;
-            ++count;
-        }
-        return count;
-    }
-
     // is aggregate deprecated?
     final bool isDeprecated()
     {

src/aggregate.h

@@ -122,8 +122,6 @@ class AggregateDeclaration : public ScopeDsymbol
         unsigned memsize, unsigned memalignsize, structalign_t memalign,
         unsigned *paggsize, unsigned *paggalignsize, bool isunion);
     Type *getType();
-    int firstFieldInUnion(int indx); // first field in union that includes indx
-    int numFieldsInUnion(int firstIndex); // #fields in union starting at index
     bool isDeprecated();         // is aggregate deprecated?
     bool isNested();
     void makeNested();

src/dinterpret.d

@@ -3682,14 +3682,13 @@ public:
             }
             assert(0 <= fieldi && fieldi < sle.elements.dim);
             // If it's a union, set all other members of this union to void
-            if (ex.op == TOKstructliteral)
+            if (ex.op == TOKstructliteral && v.overlapped)
             {
                 assert(sle.sd);
-                int unionStart = sle.sd.firstFieldInUnion(fieldi);
-                int unionSize = sle.sd.numFieldsInUnion(fieldi);
-                for (int i = unionStart; i < unionStart + unionSize; ++i)
+                for (size_t i = 0; i < sle.sd.fields.dim; i++)
                 {
-                    if (i == fieldi)
+                    VarDeclaration v2 = sle.sd.fields[i];
+                    if (!v.isOverlappedWith(v2))
                         continue;
                     Expression* exp = &(*sle.elements)[i];
                     if ((*exp).op != TOKvoid)

test/runnable/interpret.d

@@ -3323,6 +3323,34 @@ void test113()
     }
 }
 
+/************************************************/
+// 14862
+
+struct S14862
+{
+    union
+    {
+        struct { uint hi, lo; }
+        ulong data;
+    }
+
+    this(ulong data)
+    {
+        this.data = data;
+    }
+}
+
+void test14862()
+{
+           S14862 s14862 = S14862(123UL);
+      enum S14862 e14862 = S14862(123UL);
+    static S14862 g14862 = S14862(123UL);
+
+    assert(s14862.data == 123UL);   // OK
+    assert(e14862.data == 123UL);   // OK
+    assert(g14862.data == 123UL);   // OK <- fail
+}
+
 /************************************************/
 
 int main()
@@ -3443,6 +3471,7 @@ int main()
     test8818();
     test9023();
     test9954();
+    test14862();
 
     printf("Success\n");
     return 0;