Get this working, mostly

There's still something subtly wrong, but I haven't diagnosed what. The
new tests that reference the qdeql interpreter are ccompletely broken as
a result, and therefore commented out. Further testing and bugfixing is
required.

Author: bbrk24

qdeql/disassembly.txt

@@ -296,7 +296,7 @@ ct_bgn_not_end:
 ct_bgn_not_end_cleanup:
 	POP	; Remove the uop from the stack
 	DEC	; Advance the PC
-	JMP ct_find_end_loop
+	JMP ct_bgn_find_end_loop
 ct_bgn_found_end:
 ; If PC is pointing at the end uop, the stack layout is this:
 ; +======+------+----+

src/any_program_holder.hh

@@ -6,8 +6,8 @@
 template<typename IP>
 class any_program_holder {
 public:
-    virtual void advance(IP& ip, std::function<bool()> go_left) const = 0;
-    virtual instruction at(const IP& ip) const = 0;
-    virtual std::string raw_at(const IP& ip) const = 0;
+    virtual void advance(IP& ip, std::function<bool()> go_left) = 0;
+    virtual instruction at(const IP& ip) = 0;
+    virtual std::string raw_at(const IP& ip) = 0;
     virtual std::pair<size_t, size_t> get_coords(const IP& ip) const = 0;
 };

src/assembly_scanner.cpp

@@ -87,7 +87,9 @@ NONNULL_PTR(const std::vector<NONNULL_PTR(std::vector<instruction>)>) assembly_s
             string label = curr_line.substr(0, i);
 
             DISCARD label_names.insert(label);
-            auto p = label_locations.insert({ label, get_current_location() });
+            // Add a NOP for the label to point to
+            add_instruction({ instruction::operation::NOP, instruction::argument() });
+            auto p = m_label_locations.insert({ label, get_current_location() });
 
             if (!p.second) {
                 cerr << "Label '" << label << "' appears twice" << endl;
@@ -182,6 +184,10 @@ NONNULL_PTR(const std::vector<NONNULL_PTR(std::vector<instruction>)>) assembly_s
         }
     }
 
+    // for (const auto& el : m_label_locations) {
+    //     std::cout << "{ " << el.second.first << ", " << el.second.second << " }: " << el.first << std::endl;
+    // }
+
     // Second pass
     for (auto* fragment : *m_fragments) {
         for (auto& instr : *fragment) {
@@ -196,35 +202,41 @@ NONNULL_PTR(const std::vector<NONNULL_PTR(std::vector<instruction>)>) assembly_s
     return m_fragments;
 }
 
-void assembly_scanner::advance(IP& ip, std::function<bool()> go_left) const {
-    assert(m_fragments != nullptr);
+void assembly_scanner::advance(IP& ip, std::function<bool()> go_left) {
+    instruction i = at(ip);
 
-    const IP* to_left = at(ip).first_if_branch();
+    if (i.get_op() == instruction::operation::JMP) {
+        ip = i.get_arg().next;
+        return;
+    }
+
+    const IP* to_left = i.second_if_branch();
     if (to_left != nullptr && go_left()) {
         ip = *to_left;
-        return;
     }
 
     ip.second++;
-    if (ip.second > m_fragments->at(ip.first)->size()) {
+    if (ip.second >= m_fragments->at(ip.first)->size()) {
         ip.first++;
         ip.second = 0;
     }
-    if (ip.first > m_fragments->size()) {
+    if (ip.first >= m_fragments->size()) {
         ip.first = 0;
     }
 }
 
-string assembly_scanner::raw_at(const IP& ip) const {
+string assembly_scanner::raw_at(const IP& ip) {
     // TODO: call disassembler::to_str (move it to somewhere common?)
-    return "";
+    char buf[12];
+    snprintf(buf, sizeof buf, "%" PRId32, static_cast<int32_t>(at(ip).get_op()));
+    return string(buf);
 }
 
 assembly_scanner::IP assembly_scanner::get_current_location() const {
     size_t first = this->m_fragments->size();
     size_t second = 0;
-    if (first > 0) {
-        --first;
+    --first;
+    if (first != SIZE_MAX) {
         const auto* ptr = this->m_fragments->at(first);
         second = ptr->size();
         if (second > 0) {
@@ -256,7 +268,13 @@ void assembly_scanner::fake_location_to_real(IP& p) const {
 #endif
         static_cast<uintptr_t>(p.second);
     auto ptr = reinterpret_cast<NONNULL_PTR(const string)>(reconstructed);
-    p = label_locations.find(*ptr)->second;
+    const string& str = *ptr;
+    auto loc = m_label_locations.find(str);
+    if (loc == m_label_locations.end()) {
+        cerr << "Undeclared label '" << str << "'" << endl;
+        exit(EXIT_FAILURE);
+    }
+    p = loc->second;
 }
 
 #define DESTRINGIFY_NAME(op) \

src/assembly_scanner.hh

@@ -22,16 +22,16 @@ public:
 
     NONNULL_PTR(const std::vector<NONNULL_PTR(std::vector<instruction>)>) get_fragments();
 
-    void advance(IP& ip, std::function<bool()> go_left) const;
-    std::string raw_at(const IP& ip) const;
+    void advance(IP& ip, std::function<bool()> go_left);
+    std::string raw_at(const IP& ip);
 
     inline std::pair<size_t, size_t> get_coords(const IP& ip) const { return ip; }
-    inline instruction at(const IP& ip) const { return m_fragments->at(ip.first)->at(ip.second); }
+    inline instruction at(const IP& ip) { return get_fragments()->at(ip.first)->at(ip.second); }
 protected:
     void fake_location_to_real(IP& p) const;
     static instruction::operation opcode_for_name(const std::string& name) noexcept;
 
-    std::unordered_map<std::string, IP> label_locations;
+    std::unordered_map<std::string, IP> m_label_locations;
 private:
     IP get_current_location() const;
     void add_instruction(instruction&& i);

src/instruction.hh

@@ -67,6 +67,16 @@ public:
         }
     }
 
+    CONSTEXPR_UNION const pair<size_t>* second_if_branch() const noexcept {
+        switch (m_op) {
+            case operation::BNG:
+            case operation::TSP:
+                return &this->m_arg.choice.second;
+            default:
+                return nullptr;
+        }
+    }
+
     constexpr operation get_op() const noexcept { return m_op; }
     CONSTEXPR_UNION const argument& get_arg() const noexcept { return m_arg; }
 protected:

src/interpreter.hh

@@ -14,8 +14,8 @@ extern "C" void send_thread_count(size_t tc);
 template<class ProgramHolder>
 class interpreter {
 public:
-    inline interpreter(const ProgramHolder& p, flags f) noexcept :
-        m_program_holder(p), m_threads{ thread<ProgramHolder>(p, f) } {}
+    inline interpreter(ProgramHolder& p, flags f) noexcept :
+        m_program_holder(p), m_threads{ thread<ProgramHolder>(&p, f) } {}
 
     inline void run() {
         using status = typename thread<ProgramHolder>::status;
@@ -152,11 +152,18 @@ private:
 
     inline void split_thread(std::vector<thread<ProgramHolder>>& new_threads, const thread<ProgramHolder>& old_thread)
         const {
-        new_threads.push_back(old_thread);
-        new_threads.push_back(old_thread);
+        thread<ProgramHolder> new_thread_1 = old_thread;
+        new_thread_1.m_status = thread<ProgramHolder>::status::active;
+        thread<ProgramHolder> new_thread_2 = new_thread_1;
+
+        m_program_holder.advance(new_thread_1.m_ip, []() { return true; });
+        m_program_holder.advance(new_thread_2.m_ip, []() { return false; });
+
+        new_threads.push_back(new_thread_1);
+        new_threads.push_back(new_thread_2);
     }
 
-    const ProgramHolder& m_program_holder;
+    ProgramHolder& m_program_holder;
     std::vector<thread<ProgramHolder>> m_threads;
 };
 

src/program_walker.hh

@@ -52,7 +52,7 @@ public:
 
     constexpr program_walker(NONNULL_PTR(const program) p) noexcept : m_program(p) {}
 
-    inline void advance(IP& ip, std::function<bool()> go_left) const {
+    inline void advance(IP& ip, std::function<bool()> go_left) {
         int24_t op = m_program->at(ip.coords.first, ip.coords.second);
         switch (op) {
             case MIR_EW:
@@ -80,7 +80,7 @@ public:
         program_walker::advance(ip, m_program->side_length());
     }
 
-    inline instruction at(const IP& ip) const noexcept {
+    inline instruction at(const IP& ip) noexcept {
         int24_t op = m_program->at(ip.coords.first, ip.coords.second);
         if (is_branch(op, ip.dir)) {
             if (op == static_cast<int24_t>(THR_E) || op == static_cast<int24_t>(THR_W)) {
@@ -96,7 +96,7 @@ public:
 
     inline std::pair<size_t, size_t> get_coords(const IP& ip) const { return ip.coords; }
 
-    inline std::string raw_at(const IP& ip) const {
+    inline std::string raw_at(const IP& ip) {
         std::ostringstream oss;
         print_unichar(m_program->at(ip.coords.first, ip.coords.second), oss);
         return oss.str();

src/thread.hh

@@ -82,20 +82,20 @@ public:
         static std::uniform_int_distribution<int32_t> distr(INT24_MIN, INT24_MAX);
 
         // The operation currently being executed
-        instruction instr = m_program_holder.at(m_ip);
+        instruction instr = m_program_holder->at(m_ip);
         operation op = instr.get_op();
 
         // The web interface needs every thread to send debug info. The CLI expects only active threads to do so.
 #ifdef __EMSCRIPTEN__
         if (m_flags.debug) {
-            pair<size_t, size_t> coords = m_program_holder.get_coords(m_ip);
+            pair<size_t, size_t> coords = m_program_holder->get_coords(m_ip);
             send_debug_info(
                 m_number,
                 m_flags.show_stack ? m_stack.data() : nullptr,
                 m_stack.size(),
                 coords.first,
                 coords.second,
-                m_program_holder.raw_at(m_ip).c_str()
+                m_program_holder->raw_at(m_ip).c_str()
             );
         }
 #endif
@@ -117,14 +117,14 @@ public:
 #ifndef __EMSCRIPTEN__
         // Print the requisite information in debug mode.
         if (m_flags.debug) {
-            pair<size_t, size_t> coords = m_program_holder.get_coords(m_ip);
+            pair<size_t, size_t> coords = m_program_holder->get_coords(m_ip);
             send_debug_info(
                 m_number,
                 m_flags.show_stack ? m_stack.data() : nullptr,
                 m_stack.size(),
                 coords.first,
                 coords.second,
-                m_program_holder.raw_at(m_ip).c_str()
+                m_program_holder->raw_at(m_ip).c_str()
             );
         }
 #endif
@@ -133,6 +133,7 @@ public:
         switch (op) {
             case operation::BNG:
             case operation::NOP:
+            case operation::JMP:
                 break;
             case operation::ADD: {
                 SIZE_CHECK("add from", 2);
@@ -464,7 +465,7 @@ public:
             default: {
                 cerr << "Unrecognized opcode '";
                 print_unichar(static_cast<int24_t>(op), cerr);
-                pair<size_t, size_t> coords = m_program_holder.get_coords(m_ip);
+                pair<size_t, size_t> coords = m_program_holder->get_coords(m_ip);
                 cerr << "' (at (" << coords.first << ", " << coords.second << "))\n";
                 thread<ProgramHolder>::flush_and_exit(EXIT_FAILURE);
             }
@@ -478,19 +479,18 @@ public:
 
 #undef SIZE_CHECK
 protected:
-    inline thread(const ProgramHolder& ph, flags f) noexcept :
+    inline thread(ProgramHolder* ph, flags f) noexcept :
         m_program_holder(ph), m_stack(), m_ip(), m_status(status::active), m_flags(f), m_number(thread_count++) {}
 
     constexpr void advance() noexcept {
-        // FIXME: Segfaults when spawning a new thread with an empty stack
-        m_program_holder.advance(m_ip, [&]() NOEXCEPT_T {
+        m_program_holder->advance(m_ip, [&]() NOEXCEPT_T {
             EMPTY_PROTECT("branch on") {}
             return m_stack.back() < INT24_C(0);
         });
     }
 #undef EMPTY_PROTECT
 
-    ProgramHolder m_program_holder;
+    ProgramHolder* m_program_holder;
     std::vector<int24_t> m_stack;
     NO_UNIQUE_ADDRESS typename ProgramHolder::IP m_ip;
     status m_status;

tests/cli/assembly/cat.txt

@@ -0,0 +1,8 @@
+start:
+    GTC
+    BNG end
+    PTC
+    POP
+    JMP start
+end:
+    EXT

tests/cli/assembly/index.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+set -eu
+
+# Adapted from https://cedwards.xyz/defer-for-shell/
+DEFER=''
+defer () {
+    DEFER="$*; $DEFER"
+    # shellcheck disable=SC2064
+    trap "{ $DEFER}" EXIT
+}
+
+text='
+    /\_/\           ___
+   = ಠ_ಠ =_______    \ \
+    __^      __(  \.__) )
+(@)<_____>__(_____)____/'
+
+folder=$(dirname "$0")
+
+errors=$(mktemp)
+defer rm "$errors"
+
+output=$($TRILANGLE -fwA "${folder}/cat.txt" <<<"$text" 2>"$errors")
+test ! -s "$errors"
+test "$text" = "${output//$'\r'/}"