oceani: add comments to var_block_close() and remove dead code.

[ocean] / csrc / oceani.mdc

diff --git a/csrc/oceani.mdc b/csrc/oceani.mdc
index 04cae63a944360db4e963e1f43a622b05b785854..7e1f2ac788117dddae2f9e2529e3d34ec8389aac 100644 (file)
--- a/csrc/oceani.mdc
+++ b/csrc/oceani.mdc
@@ -1141,7 +1141,14 @@ all pending-scope variables become conditionally scoped.
 
        static void var_block_close(struct parse_context *c, enum closetype ct)
        {
-               /* Close off all variables that are in_scope */
+               /* Close off all variables that are in_scope.
+                * Some variables in c->scope may already be not-in-scope,
+                * such as when a PendingScope variable is hidden by a new
+                * variable with the same name.
+                * So we check for v->name->var != v and drop them.
+                * If we choose to make a variable OutScope, we drop it
+                * immediately too.
+                */
                struct variable *v, **vp, *v2;
 
                scope_pop(c);
@@ -1151,12 +1158,11 @@ all pending-scope variables become conditionally scoped.
                     ? (*vp =  v->in_scope, 0)
                     : ( vp = &v->in_scope, 0)) {
                        v->min_depth = c->scope_depth;
-                       if (v->name->var != v) {
+                       if (v->name->var != v)
                                /* This is still in scope, but we haven't just
                                 * closed the scope.
                                 */
                                continue;
-                       }
                        switch (ct) {
                        case CloseElse:
                        case CloseParallel: /* handle PendingScope */
@@ -1164,14 +1170,15 @@ all pending-scope variables become conditionally scoped.
                                case InScope:
                                case CondScope:
                                        if (c->scope_stack->child_count == 1)
+                                               /* first among parallel branches */
                                                v->scope = PendingScope;
                                        else if (v->previous &&
                                                 v->previous->scope == PendingScope)
+                                               /* all previous branches used name */
                                                v->scope = PendingScope;
                                        else if (v->type == Tlabel)     // UNTESTED
+                                               /* Labels remain pending even when not used */
                                                v->scope = PendingScope;        // UNTESTED
-                                       else if (v->name->var == v)     // UNTESTED
-                                               v->scope = OutScope;    // UNTESTED
                                        if (ct == CloseElse) {
                                                /* All Pending variables with this name
                                                 * are now Conditional */
@@ -1182,13 +1189,16 @@ all pending-scope variables become conditionally scoped.
                                        }
                                        break;
                                case PendingScope:
-                                       for (v2 = v;
-                                            v2 && v2->scope == PendingScope;
-                                            v2 = v2->previous)
-                                               if (v2->type != Tlabel)
-                                                       v2->scope = OutScope;
-                                       break;
-                               case OutScope: break;   // UNTESTED
+                                       /* Not possible as it would require
+                                        * parallel scope to be nested immediately
+                                        * in a parallel scope, and that never
+                                        * happens.
+                                        */
+                               case OutScope:
+                                       /* Not possible as we already tested for
+                                        * OutScope
+                                        */
+                                       abort();                // NOTEST
                                }
                                break;
                        case CloseSequential: