fix Issue 20183 - Assigning statement scope of struct literal or temp…

…orary to variable with longer lifetime

src/dmd/escape.d

@@ -25,6 +25,7 @@ import dmd.errors;
 import dmd.expression;
 import dmd.func;
 import dmd.globals;
+import dmd.id;
 import dmd.identifier;
 import dmd.init;
 import dmd.mtype;
@@ -889,6 +890,28 @@ ByRef:
             continue;
         }
 
+        if (va && ee.op == TOK.call && ee.type.toBasetype().ty == Tstruct &&
+            !(va.storage_class & STC.temp) && va.ident != Id.withSym &&
+            sc.func.setUnsafe())
+        {
+            if (!gag)
+                error(ee.loc, "address of struct temporary returned by `%s` assigned to longer lived variable `%s`",
+                    ee.toChars(), va.toChars());
+            result = true;
+            continue;
+        }
+
+        if (va && ee.op == TOK.structLiteral &&
+            !(va.storage_class & STC.temp) && va.ident != Id.withSym &&
+            sc.func.setUnsafe())
+        {
+            if (!gag)
+                error(ee.loc, "address of struct literal `%s` assigned to longer lived variable `%s`",
+                    ee.toChars(), va.toChars());
+            result = true;
+            continue;
+        }
+
         if (va && !va.isDataseg() && !va.doNotInferScope)
         {
             if (!va.isScope() && inferScope)

test/fail_compilation/fail20183.d

@@ -0,0 +1,28 @@
+/* REQUIRED_ARGS: -preview=dip1000
+TEST_OUTPUT:
+---
+fail_compilation/fail20183.d(1016): Error: cannot modify constant expression `S(0).i`
+fail_compilation/fail20183.d(1017): Error: address of struct temporary returned by `s()` assigned to longer lived variable `q`
+---
+ */
+
+#line 1000
+
+// https://issues.dlang.org/show_bug.cgi?id=20183
+
+@safe:
+
+int* addr(return ref int b) { return &b; }
+
+struct S
+{
+    int i;
+}
+
+S s() { return S(); }
+
+void test()
+{
+    int* p = addr(S().i);  // struct literal
+    int* q = addr(s().i);  // struct temporary
+}

test/fail_compilation/retscope.d

@@ -8,7 +8,7 @@ fail_compilation/retscope.d(33): Error: returning `b ? nested1(& i) : nested2(&
 fail_compilation/retscope.d(46): Error: scope variable `p` assigned to non-scope `q`
 fail_compilation/retscope.d(48): Error: address of variable `i` assigned to `q` with longer lifetime
 fail_compilation/retscope.d(49): Error: scope variable `a` assigned to non-scope `b`
-fail_compilation/retscope.d(50): Error: reference to stack allocated value returned by `(*fp2)()` assigned to non-scope `q`
+fail_compilation/retscope.d(50): Error: address of struct temporary returned by `(*fp2)()` assigned to longer lived variable `q`
 ---
 */