remove separate stack_state

include/cubescript/cubescript/error.hh

@@ -18,61 +18,6 @@ namespace cubescript {
 
 struct state;
 
-/** @brief Represents the simplified call stack at a point in time.
- *
- * This is a simplified call stack; it is generally carried by errors
- * and can be utilized to print out a stack trace.
- *
- * The actual stack is represented as a linked list of nodes. There can
- * be a gap in the list, if the user has limited the maximum debug depth
- * with the `dbgalias` cubescript variable; the bottommost node will always
- * represent the bottom of the stack, while the nodes above it will be the
- * rest of the stack or a part of the stack starting from the top.
- */
-struct LIBCUBESCRIPT_EXPORT stack_state {
-    /** @brief A node in the call stack.
-     *
-     * The nodes are indexed. The bottommost node has index 1, the topmost
-     * node has index N (where N is the number of levels the call stack has).
-     */
-    struct node {
-        node const *next; /**< @brief Next level. */
-        struct ident const *id; /**< @brief The ident of this level. */
-        std::size_t index; /**< @brief The level index. */
-    };
-
-    stack_state() = delete;
-
-    /** @brief Construct the stack state. */
-    stack_state(state &cs, node *nd = nullptr);
-
-    stack_state(stack_state const &) = delete;
-
-    /** @brief Move the stack state somewhere else.
-     *
-     * Stack states are movable, but not copyable.
-     */
-    stack_state(stack_state &&st);
-
-    /** @brief Destroy the stack state. */
-    ~stack_state();
-
-    stack_state &operator=(stack_state const &) = delete;
-
-    /** @brief Move-assign the stack state somewhere else.
-     *
-     * Stack states are move assignable, but not copy assignable.
-     */
-    stack_state &operator=(stack_state &&);
-
-    /** @brief Get the pointer to the topmost (current) level. */
-    node const *get() const;
-
-private:
-    state &p_state;
-    node *p_node;
-};
-
 /** @brief Represents a Cubescript error.
  *
  * This is a standard error that can be thrown by either the Cubescript APIs
@@ -86,7 +31,21 @@ private:
  * which is reused for each error raised from that thread.
  */
 struct LIBCUBESCRIPT_EXPORT error {
-    friend struct state;
+    /** @brief A node in the call stack.
+     *
+     * The nodes are indexed. The bottommost node has index 1, the topmost
+     * node has index N (where N is the number of levels the call stack has).
+     *
+     * There can be a gap in the stack (i.e. the bottommost node will have
+     * index 1 and the one above it greater than 2). The gap is controlled
+     * by the value of the `dbgalias` cubescript variable at the time of
+     * creation of the error (the stack list will contain at most N nodes).
+     */
+    struct stack_node {
+        stack_node const *next; /**< @brief Next level. */
+        struct ident const *id; /**< @brief The ident of this level. */
+        std::size_t index; /**< @brief The level index. */
+    };
 
     error() = delete;
     error(error const &) = delete;
@@ -94,24 +53,27 @@ struct LIBCUBESCRIPT_EXPORT error {
     /** @brief Errors are move constructible. */
     error(error &&v):
         p_errbeg{v.p_errbeg}, p_errend{v.p_errend},
-        p_stack{std::move(v.p_stack)}
+        p_stack{std::move(v.p_stack)}, p_state{v.p_state}
     {}
 
     /** @brief Construct an error using a string. */
     error(state &cs, std::string_view msg);
 
+    /** @brief Destroy the error. */
+    ~error();
+
     /** @brief Get a view of the error message. */
     std::string_view what() const {
         return std::string_view{p_errbeg, std::size_t(p_errend - p_errbeg)};
     }
 
     /** @brief Get a reference to the call stack state. */
-    stack_state &stack() {
+    stack_node *stack() {
         return p_stack;
     }
 
     /** @brief Get a reference to the call stack state. */
-    stack_state const &stack() const {
+    stack_node const *stack() const {
         return p_stack;
     }
 private:
@@ -120,7 +82,8 @@ private:
     error(state &cs, char const *errbeg, char const *errend);
 
     char const *p_errbeg, *p_errend;
-    stack_state p_stack;
+    stack_node *p_stack;
+    state *p_state;
 };
 
 } /* namespace cubescript */

include/cubescript/cubescript/util.hh

@@ -293,9 +293,8 @@ inline R unescape_string(R writer, std::string_view str) {
  * @return `writer` after writing into it
  */
 template<typename R>
-inline R print_stack(R writer, stack_state const &st) {
+inline R print_stack(R writer, typename error::stack_node const *nd) {
     char buf[32] = {0};
-    auto nd = st.get();
     std::size_t pindex = 1;
     while (nd) {
         auto name = nd->id->name();

src/cs_error.cc

@@ -8,56 +8,26 @@
 
 namespace cubescript {
 
-LIBCUBESCRIPT_EXPORT stack_state::stack_state(
-    state &cs, node *nd
-):
-    p_state{cs}, p_node{nd}
-{}
-
-LIBCUBESCRIPT_EXPORT stack_state::stack_state(stack_state &&st):
-    p_state{st.p_state}, p_node{st.p_node}
-{
-    st.p_node = nullptr;
-}
-
-LIBCUBESCRIPT_EXPORT stack_state::~stack_state() {
-    size_t len = 0;
-    for (node const *nd = p_node; nd; nd = nd->next) {
-        ++len;
-    }
-    state_p{p_state}.ts().istate->destroy_array(p_node, len);
-}
-
-LIBCUBESCRIPT_EXPORT stack_state &stack_state::operator=(stack_state &&st) {
-    p_node = st.p_node;
-    st.p_node = nullptr;
-    return *this;
-}
-
-LIBCUBESCRIPT_EXPORT stack_state::node const *stack_state::get() const {
-    return p_node;
-}
-
-static stack_state save_stack(state &cs) {
+static typename error::stack_node *save_stack(state &cs) {
     auto &ts = state_p{cs}.ts();
     builtin_var *dalias = ts.istate->ivar_dbgalias;
     auto dval = std::clamp(
         dalias->value().get_integer(), integer_type(0), integer_type(1000)
     );
     if (!dval) {
-        return stack_state{cs, nullptr};
+        return nullptr;
     }
     int total = 0, depth = 0;
     for (ident_link *l = ts.callstack; l; l = l->next) {
         total++;
     }
     if (!total) {
-        return stack_state{cs, nullptr};
+        return nullptr;
     }
-    stack_state::node *st = ts.istate->create_array<stack_state::node>(
+    auto *st = ts.istate->create_array<typename error::stack_node>(
         std::min(total, dval)
     );
-    stack_state::node *ret = st, *nd = st;
+    typename error::stack_node *ret = st, *nd = st;
     ++st;
     for (ident_link *l = ts.callstack; l; l = l->next) {
         ++depth;
@@ -76,11 +46,19 @@ static stack_state save_stack(state &cs) {
             nd->next = nullptr;
         }
     }
-    return stack_state{cs, ret};
+    return ret;
+}
+
+LIBCUBESCRIPT_EXPORT error::~error() {
+    std::size_t slen = 0;
+    for (stack_node const *nd = p_stack; nd; nd = nd->next) {
+        ++slen;
+    }
+    state_p{*p_state}.ts().istate->destroy_array(p_stack, slen);
 }
 
 LIBCUBESCRIPT_EXPORT error::error(state &cs, std::string_view msg):
-    p_errbeg{}, p_errend{}, p_stack{cs}
+    p_errbeg{}, p_errend{}, p_state{&cs}
 {
     char *sp;
     char *buf = state_p{cs}.ts().request_errbuf(msg.size(), sp);
@@ -93,7 +71,7 @@ LIBCUBESCRIPT_EXPORT error::error(state &cs, std::string_view msg):
 
 LIBCUBESCRIPT_EXPORT error::error(
     state &cs, char const *errbeg, char const *errend
-): p_errbeg{errbeg}, p_errend{errend}, p_stack{cs} {
+): p_errbeg{errbeg}, p_errend{errend}, p_state{&cs} {
     p_stack = save_stack(cs);
 }
 

src/lib_base.cc

@@ -84,7 +84,7 @@ LIBCUBESCRIPT_EXPORT void std_init_base(state &gcs) {
             result = args[0].get_code().call(cs);
         } catch (error const &e) {
             result.set_string(e.what(), cs);
-            if (e.stack().get()) {
+            if (e.stack()) {
                 charbuf buf{cs};
                 print_stack(std::back_inserter(buf), e.stack());
                 tback.set_string(buf.str(), cs);

tools/repl.cc

@@ -253,7 +253,7 @@ static bool do_call(cs::state &cs, std::string_view line, bool file = false) {
         std::printf(
             "%s%s\n", !is_lnum ? "stdin: " : "stdin:", e.what().data()
         );
-        if (e.stack().get()) {
+        if (e.stack()) {
             std::string str;
             cs::print_stack(std::back_inserter(str), e.stack());
             std::printf("%s\n", str.data());