Merge pull request #5973 from WalterBright/fix16292

fix Issue 16292 - [REG2.069] bogus Error: goto skips declaration of v…

src/declaration.d

@@ -126,6 +126,7 @@ enum STCvolatile            = (1L << 43);   // destined for volatile in the back
 enum STCreturn              = (1L << 44);   // 'return ref' for function parameters
 enum STCautoref             = (1L << 45);   // Mark for the already deduced 'auto ref' parameter
 enum STCinference           = (1L << 46);   // do attribute inference
+enum STCexptemp             = (1L << 47);   // temporary variable that has lifetime restricted to an expression
 
 enum STC_TYPECTOR = (STCconst | STCimmutable | STCshared | STCwild);
 enum STC_FUNCATTR = (STCref | STCnothrow | STCnogc | STCpure | STCproperty | STCsafe | STCtrusted | STCsystem);

src/expression.d

@@ -2343,7 +2343,10 @@ extern (C++) Expression extractOpDollarSideEffect(Scope* sc, UnaExp ue)
          *      (ref __dop = e1, __dop).opIndex( ... __dop.opDollar ...)
          *      (ref __dop = e1, __dop).opSlice( ... __dop.opDollar ...)
          */
-        e1 = extractSideEffect(sc, "__dop", e0, e1);
+        e1 = extractSideEffect(sc, "__dop", e0, e1, false);
+        assert(e1.op == TOKvar);
+        VarExp ve = cast(VarExp)e1;
+        ve.var.storage_class |= STCexptemp;     // lifetime limited to expression
     }
     ue.e1 = e1;
     return e0;

src/statement.d

@@ -2590,6 +2590,10 @@ extern (C++) final class GotoStatement : Statement
         {
             // All good, the label's scope has no variables
         }
+        else if (vd.storage_class & STCexptemp)
+        {
+            // Lifetime ends at end of expression, so no issue with skipping the statement
+        }
         else if (vd.ident == Id.withSym)
         {
             error("goto skips declaration of with temporary at %s", vd.loc.toChars());

test/compilable/test16292.d

@@ -0,0 +1,19 @@
+/* PERMUTE_ARGS:
+ */
+// https://issues.dlang.org/show_bug.cgi?id=16292
+
+void main()
+{
+    goto label;
+    if (makeS()[0])
+    {
+        label:
+    }
+}
+
+S makeS() { return S(); }
+
+struct S
+{
+    int opIndex(size_t i) { return 0; }
+}