From 95e7ae320c4bd35456021f55234abbe21be7ab57 Mon Sep 17 00:00:00 2001
From: Daniel Kolesa <daniel@octaforge.org>
Date: Fri, 2 Apr 2021 23:50:35 +0200
Subject: [PATCH] simplify alias_stack push/pop a bit

---
 src/cs_ident.cc | 20 ++++++++++++--------
 src/cs_ident.hh |  3 +++
 src/cs_vm.cc    | 31 +++++++++----------------------
 3 files changed, 24 insertions(+), 30 deletions(-)

diff --git a/src/cs_ident.cc b/src/cs_ident.cc
index 3dba1a1..3eb0508 100644
--- a/src/cs_ident.cc
+++ b/src/cs_ident.cc
@@ -134,13 +134,20 @@ bool ident_is_used_arg(ident *id, thread_state &ts) {
     return ts.callstack->usedargs[id->get_index()];
 }
 
+void alias_stack::push(ident_stack &st) {
+    st.next = node;
+    node = &st;
+}
+
+void alias_stack::pop() {
+    node = node->next;
+}
+
 void alias_stack::set_arg(alias *a, thread_state &ts, any_value &v) {
     if (ident_is_used_arg(a, ts)) {
         node->code = bcode_ref{};
     } else {
-        auto &st = ts.idstack.emplace_back(*ts.pstate);
-        st.next = node;
-        node = &st;
+        push(ts.idstack.emplace_back(*ts.pstate));
         ts.callstack->usedargs[a->get_index()] = true;
     }
     node->val_s = std::move(v);
@@ -356,17 +363,14 @@ LIBCUBESCRIPT_EXPORT alias_local::alias_local(state &cs, ident *a) {
     auto &ts = *cs.thread_pointer();
     p_alias = static_cast<alias *>(a);
     auto &ast = ts.get_astack(p_alias);
-    auto &st = ts.idstack.emplace_back(cs);
-    st.next = ast.node;
-    ast.node = &st;
+    ast.push(ts.idstack.emplace_back(cs));
     p_sp = &ast;
     static_cast<alias_impl *>(p_alias)->p_flags &= ~IDENT_FLAG_UNKNOWN;
 }
 
 LIBCUBESCRIPT_EXPORT alias_local::~alias_local() {
     if (p_alias) {
-        auto &st = *static_cast<alias_stack *>(p_sp);
-        st.node = st.node->next;
+        static_cast<alias_stack *>(p_sp)->pop();
     }
 }
 
diff --git a/src/cs_ident.hh b/src/cs_ident.hh
index 3223c7e..d2545f7 100644
--- a/src/cs_ident.hh
+++ b/src/cs_ident.hh
@@ -26,6 +26,9 @@ struct ident_stack {
 struct alias_stack {
     ident_stack *node;
 
+    void push(ident_stack &st);
+    void pop();
+
     void set_arg(alias *a, thread_state &ts, any_value &v);
     void set_alias(alias *a, thread_state &ts, any_value &v);
 };
diff --git a/src/cs_vm.cc b/src/cs_vm.cc
index 58ed22e..1560e92 100644
--- a/src/cs_vm.cc
+++ b/src/cs_vm.cc
@@ -12,18 +12,14 @@ namespace cubescript {
 static inline void push_alias(thread_state &ts, ident *id, ident_stack &st) {
     if (id->is_alias() && !(id->get_flags() & IDENT_FLAG_ARG)) {
         auto *aimp = static_cast<alias_impl *>(id);
-        auto &ast = ts.get_astack(aimp);
-        st.next = ast.node;
-        ast.node = &st;
+        ts.get_astack(aimp).push(st);
         aimp->p_flags &= ~IDENT_FLAG_UNKNOWN;
     }
 }
 
 static inline void pop_alias(thread_state &ts, ident *id) {
     if (id->is_alias() && !(id->get_flags() & IDENT_FLAG_ARG)) {
-        auto *aimp = static_cast<alias_impl *>(id);
-        auto &ast = ts.get_astack(aimp);
-        ast.node = ast.node->next;
+        ts.get_astack(static_cast<alias *>(id)).pop();
     }
 }
 
@@ -224,8 +220,7 @@ bool exec_alias(
             static_cast<alias *>(ts.istate->identmap[i])
         );
         auto &st = ts.idstack.emplace_back(*ts.pstate);
-        st.next = ast.node;
-        ast.node = &st;
+        ast.push(st);
         st.val_s = std::move(args[offset + i]);
         uargs[i] = true;
     }
@@ -250,18 +245,16 @@ bool exec_alias(
         ts.pstate->identflags = oldflags;
         auto amask = aliaslink.usedargs;
         for (std::size_t i = 0; i < callargs; i++) {
-            auto &ast = ts.get_astack(
+            ts.get_astack(
                 static_cast<alias *>(ts.istate->identmap[i])
-            );
-            ast.node = ast.node->next;
+            ).pop();
             amask[i] = false;
         }
         for (; amask.any(); ++callargs) {
             if (amask[callargs]) {
-                auto &ast = ts.get_astack(
+                ts.get_astack(
                     static_cast<alias *>(ts.istate->identmap[callargs])
-                );
-                ast.node = ast.node->next;
+                ).pop();
                 amask[callargs] = false;
             }
         }
@@ -763,10 +756,7 @@ std::uint32_t *vm_exec(
                     (a->get_flags() & IDENT_FLAG_ARG) &&
                     !ident_is_used_arg(a, ts)
                 ) {
-                    auto &ast = ts.get_astack(a);
-                    auto &st = ts.idstack.emplace_back(*ts.pstate);
-                    st.next = ast.node;
-                    ast.node = &st;
+                    ts.get_astack(a).push(ts.idstack.emplace_back(*ts.pstate));
                     ts.callstack->usedargs[a->get_index()] = true;
                 }
                 args.emplace_back(cs).set_ident(a);
@@ -783,10 +773,7 @@ std::uint32_t *vm_exec(
                     !ident_is_used_arg(id, ts)
                 ) {
                     auto *a = static_cast<alias *>(id);
-                    auto &ast = ts.get_astack(a);
-                    auto &st = ts.idstack.emplace_back(*ts.pstate);
-                    st.next = ast.node;
-                    ast.node = &st;
+                    ts.get_astack(a).push(ts.idstack.emplace_back(*ts.pstate));
                     ts.callstack->usedargs[id->get_index()] = true;
                 }
                 arg.set_ident(id);