Merge pull request #8036 from WalterBright/fix18484

fix Issue 18484 - [dip1000] Subtype allows reference to escape with i…
merged-on-behalf-of: Walter Bright <WalterBright@users.noreply.github.com>

src/dmd/escape.d

@@ -820,7 +820,12 @@ private void escapeByValue(Expression e, EscapeByResults* er)
 
         override void visit(AddrExp e)
         {
-            escapeByRef(e.e1, er);
+            /* Taking the address of struct literal is normally not
+             * allowed, but CTFE can generate one out of a new expression,
+             * but it'll be placed in static data so no need to check it.
+             */
+            if (e.e1.op != TOK.structLiteral)
+                escapeByRef(e.e1, er);
         }
 
         override void visit(SymOffExp e)
@@ -1161,6 +1166,19 @@ private void escapeByRef(Expression e, EscapeByResults* er)
             }
         }
 
+        override void visit(StructLiteralExp e)
+        {
+            if (e.elements)
+            {
+                foreach (ex; *e.elements)
+                {
+                    if (ex)
+                        ex.accept(this);
+                }
+            }
+            er.byexp.push(e);
+        }
+
         override void visit(DotVarExp e)
         {
             Type t1b = e.e1.type.toBasetype();

test/fail_compilation/test18484.d

@@ -0,0 +1,26 @@
+/* REQUIRED_ARGS: -dip1000
+TEST_OUTPUT:
+---
+fail_compilation/test18484.d(19): Error: returning `x.bar()` escapes a reference to local variable `x`
+fail_compilation/test18484.d(24): Error: escaping reference to stack allocated value returned by `S(0)`
+---
+*/
+
+// https://issues.dlang.org/show_bug.cgi?id=18484
+
+struct S
+{
+    int* bar() return;
+    int i;
+}
+
+int* test1()
+{
+    auto x = S(); return x.bar();  // error
+}
+
+int* test2()
+{
+    return S().bar();  // error
+}
+