From 79a1d566b0c76d167855ce0a3032d88c40a7cf3c Mon Sep 17 00:00:00 2001
From: janis <janis@nirgendwo.xyz>
Date: Wed, 27 May 2026 19:18:27 +0200
Subject: [PATCH] asdf2

---
 weave.cc | 555 +++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 520 insertions(+), 35 deletions(-)

diff --git a/weave.cc b/weave.cc
index 5db1a8d..76f4624 100755
--- a/weave.cc
+++ b/weave.cc
@@ -1,4 +1,3 @@
-///$(which true);FLAGS="-g -Wall -Wextra --std=c++23 -O3";c++ $FLAGS -o weave "$0" || { echo "Compilation failed"; exit 1; }; ./weave; exit 0
 #include <cstdio>
 #include <utility>
 #include <string>
@@ -9,9 +8,9 @@
 #include <sstream>
 #include <optional>
 #include <stdexcept>
-#include <cctype>
 #include <cstdint>
 #include <iostream>
+#include <ranges>
 
 // Type aliases for convenience
 using u8 = uint8_t;
@@ -35,6 +34,71 @@ template <class... Ts> struct overloads : Ts... {
   using Ts::operator()...;
 };
 
+template <usize N> struct hash_mix;
+
+template <> struct hash_mix<64> {
+  auto operator()(u64 x) const -> u64 {
+    auto const m = 0xe9846af9b1a615d;
+    x ^= x >> 32;
+    x *= m;
+    x ^= x >> 32;
+    x *= m;
+    x ^= x >> 28;
+
+    return x;
+  }
+};
+  template<> struct hash_mix<32> {
+    auto operator()(u32 x) const -> u32 {
+      const u32 m1 = 0x21f0aaad;
+      const u32 m2 = 0x735a2d97;
+
+      x ^= x >> 16;
+      x *= m1;
+      x ^= x >> 15;
+      x *= m2;
+      x ^= x >> 15;
+
+      return x;
+    }
+  };
+
+template <class T> auto hash_combine(usize  &seed, const T &value) -> usize {
+  seed =
+      hash_mix<sizeof(usize) * 8>{}(seed + 0x9e3779b9 + std::hash<T>{}(value));
+
+  return seed;
+}
+
+template <typename T>
+concept hashable = requires(const T &a) {
+  { std::hash<std::remove_cvref_t<T>>{}(a) } -> std::convertible_to<std::size_t>;
+};
+
+template <typename R, typename T>
+concept range_of = std::ranges::input_range<R> &&
+  std::convertible_to<std::ranges::range_value_t<R>, T>;
+
+
+template <typename T, typename R>
+auto hash_range(std::size_t &seed, const R &range) -> usize requires range_of<R, T> && hashable<T> {
+  for (const auto &elem : range) {
+    hash_combine(seed, elem);
+  }
+
+  return seed;
+}
+
+template <typename T, typename U>
+struct std::hash<std::pair<T, U>> {
+  std::size_t operator()(const std::pair<T, U> &p) const requires hashable<T> && hashable<U> {
+    std::size_t seed = 0;
+    hash_combine(seed, std::hash<std::remove_cvref_t<T>>{}(p.first));
+    hash_combine(seed, std::hash<std::remove_cvref_t<T>>{}(p.second));
+    return seed;
+  }
+};
+
 class CowStr {
   std::variant<std::string_view, std::string> data_;
 
@@ -250,14 +314,17 @@ enum class JsonType {
     JsonNumber(std::string_view value) : value(value) {}
   };
   struct JsonValue {
-    std::variant<JsonNull, bool, JsonNumber, std::string_view,
+    std::variant<JsonNull, bool, JsonNumber, CowStr,
                  std::vector<JsonValue>, JsonObject>
     value;
 
     JsonValue() : value(JsonNull{}) {}
     JsonValue(JsonNull null) : value(null) {}
     JsonValue(bool boolean) : value(boolean) {}
-    JsonValue(const std::string_view& str) : value(str) {}
+    JsonValue(CowStr str) : value(str) {}
+    JsonValue(std::string_view str) : value(CowStr(str)) {}
+    JsonValue(std::string str) : value(CowStr(str)) {}
+    JsonValue(const char* str) : value(CowStr(str)) {}
     JsonValue(JsonNumber number) : value(number) {}
     JsonValue(std::vector<JsonValue> array) : value(std::move(array)) {}
     JsonValue(JsonObject object) : value(std::move(object)) {}
@@ -268,7 +335,7 @@ enum class JsonType {
     }
     auto is_string() const -> bool {
 
-      return std::holds_alternative<std::string_view>(value);
+      return std::holds_alternative<CowStr>(value);
     }
     auto is_number() const -> bool {
       return std::holds_alternative<JsonNumber>(value);
@@ -294,8 +361,8 @@ enum class JsonType {
       }
     }
     auto as_string() const -> std::optional<std::string_view> {
-      if (auto pval = std::get_if<std::string_view>(&value)) {
-        return *pval;
+      if (auto pval = std::get_if<CowStr>(&value)) {
+        return pval->view();
       } else {
         return std::nullopt;
       }
@@ -333,7 +400,7 @@ enum class JsonType {
       [&](JsonNull _) { os << "null"; },
       [&](bool b) { os << (b ? "true" : "false"); },
       [&](const JsonNumber &num) { os << num.value; },
-      [&](const std::string_view &str) { os << "\"" << str << "\""; },
+      [&](const CowStr &str) { os << "\"" << str.view() << "\""; },
       [&](const JsonObject &obj) {
         os << "{";
         auto first = true;
@@ -389,25 +456,103 @@ enum class JsonType {
 
 }
 
+struct SourceFlags;
 struct Source {
   std::string_view path;
-  std::string_view flags;
-  std::string_view defines;
+  std::vector<std::string_view> flags;
+  std::unordered_map<std::string_view, std::string_view> defines;
 
   Source(std::string_view path)
-    : path(std::move(path)), flags(""), defines("") {}
-  // rule of five
-  Source(const Source &) = delete;
-  Source(Source &&) = delete;
-  Source &operator=(const Source &) = delete;
-  Source &operator=(Source &&) = delete;
+      : path(std::move(path)), flags({}), defines({}) {}
+
+  auto with_flag(std::string_view flag) -> Source & {
+    flags.push_back(flag);
+    return *this;
+  }
+
+  auto as_flags() const -> SourceFlags;
+};
+
+struct Module : public Source {
+  std::optional<std::string> name_;
+
+  Module(std::string_view path)
+      : Source(std::move(path)), name_(std::nullopt) {}
+  Module(std::string_view path, std::string name) : Source(std::move(path)), name_(std::move(name)) {}
+  Module(Source source, std::string name) : Source(source), name_(name) {}
+  Module(Source source) : Source(source), name_(std::nullopt) {}
+
+  auto name() const -> CowStr {
+    if (name_) {
+      return CowStr(*name_);
+    } else {
+      auto name = std::string(path.substr(
+          0, path.find_last_of('.'))); // remove extension
+      for (auto &slash :
+           name | std::views::filter([](char c) { return c == '/'; })) {
+        slash = '.';
+      }
+
+      return CowStr(name);
+    }
+  }
+};
+
+struct SourceFlags {
+  const Source &source;
+
+  SourceFlags(const Source &source) : source(source) {}
+
+  friend auto operator<<(std::ostream &os, const SourceFlags &sf) -> std::ostream & {
+    for (const auto &flag : sf.source.flags) {
+      os << flag << " ";
+    }
+    for (const auto &[k, v] : sf.source.defines) {
+      os << "-D" << k << "=" << v << " ";
+    }
+    return os;
+  }
+
+  friend auto operator<<(std::vector<json::JsonValue> &args, const SourceFlags &sf) -> std::vector<json::JsonValue> & {
+    for (const auto &flag : sf.source.flags) {
+      args.push_back(json::JsonValue(flag));
+    }
+    for (const auto &[k, v] : sf.source.defines) {
+      const auto define = "-D" + std::string(k) + "=" + std::string(v);
+      args.push_back(json::JsonValue(define));
+    }
+
+    return args;
+  }
+};
+
+auto Source::as_flags() const -> SourceFlags {
+  return SourceFlags(*this);
+}
+
+struct SourceHash {
+  std::size_t operator()(const Source &source) const {
+    auto path = std::hash<std::string_view>{}(source.path);
+    auto flags = hash_range<std::string_view>(path, source.flags);
+    auto defines = hash_range<std::pair<std::string_view, std::string_view>>(flags, source.defines);
+
+    return defines;
+  }
+};
+
+template <>
+struct std::hash<Source> {
+  std::size_t operator()(const Source &source) const {
+    return SourceHash{}(source);
+  }
 };
 
 struct Project {
   std::string_view name;
-  std::vector<std::string_view> sources;
+  std::vector<Source> sources;
   std::unordered_map<std::string, std::string> project_defines;
   std::vector<std::string> project_flags;
+  std::vector<Module> modules;
 
   // rule of five
   Project(const Project &) = delete;
@@ -416,10 +561,122 @@ struct Project {
   Project &operator=(Project &&) = delete;
 
   Project(std::string_view name)
-      : name(std::move(name)), sources({}), project_defines({}), project_flags({}) {}
+    : name(std::move(name)), sources({}), project_defines({}), project_flags({}), modules({}) {}
   auto add_source(std::string_view source) -> void {
+    sources.push_back(Source(std::move(source)));
+  }
+  auto add_source(Source source) -> void {
     sources.push_back(std::move(source));
   }
+  auto add_source(Source &&source) -> void {
+    sources.push_back(std::move(source));
+  }
+
+  auto add_module(Module module) -> void { modules.push_back(module); }
+
+  auto add_module(Source &&module) -> void {
+    modules.push_back({std::move(module)});
+  }
+
+  auto add_module(std::string_view module) -> void {
+    modules.push_back(Module(std::move(module)));
+  }
+
+  auto into_ninja_commands() -> std::string {
+    const auto build_dir = "target/artifacts/" + std::string(name);
+
+    auto ninja = std::ostringstream{};
+    ninja << "ninja_required_version = 1.3\n";
+    ninja << "build_dir = " << build_dir << "\n";
+    ninja << "target = " << name << "\n\n";
+    ninja << "cxxflags = ";
+
+    auto flags = project_flags | std::views::join_with(' ');
+    for (const auto& flag : flags) {
+      ninja << flag;
+    }
+    ninja << "\n";
+    ninja << "cxxdefs = ";
+    auto defines = project_defines | std::views::transform([](const auto &kv) {
+                     return "-D" + kv.first + "=" + kv.second;
+                   }) |
+                   std::views::join_with(' ');
+    for (const auto& define : defines) {
+      ninja << define;
+    }
+    ninja << "\n\n";
+
+    const std::string link_cmd = "clang++ -fuse-ld=mold";
+    const std::string cxx_cmd = "clang++";
+
+    // link rule
+    {
+      ninja << "rule link\n";
+      ninja << "  command = " << link_cmd << " -o $out $in\n\n";
+    }
+
+    // compile rule
+    {
+      ninja << "rule cc\n";
+      ninja << "  command = " << cxx_cmd << " $cxxflags $cxxdefs $fileflags $modules -c $in -o $out -MMD -MF $depfile\n";
+      ninja << "  depfile = $depfile\n";
+      ninja << "  deps = gcc\n\n";
+    }
+
+    // module rule
+    {
+      ninja << "rule cc_mod\n";
+      ninja << "  command = " << cxx_cmd
+            << " $cxxflags $cxxdefs $fileflags $in "
+               "--precompile -o $out -MMD -MF $depfile\n";
+      ninja << "  depfile = $depfile\n";
+      ninja << "  deps = gcc\n\n";
+    }
+
+    // precompile modules
+    auto module_files = std::ostringstream{};
+    for (const auto &module : modules) {
+      auto module_ss = std::ostringstream{};
+      module_ss << std::hex << std::hash<Source>{}(module);
+      const auto module_obj = module_ss.str();
+
+      ninja << "build $build_dir/" << module_obj << ".pcm: cc_mod " << module.path << "\n";
+      ninja << "  depfile = $build_dir/" << module_obj << ".d\n";
+      ninja << "  fileflags = " << module.as_flags() << "\n\n";
+
+      auto module_name = module.name();
+      module_files << "-fmodule-file=" << module_name.view() << "=" << "$build_dir/" << module_obj << ".pcm ";
+    }
+
+    ninja << "modules = " << module_files.str() << "\n\n";
+
+    // compile sources
+    auto objects = std::vector<std::string>{};
+    for (const auto &source : sources) {
+      auto object_ss = std::ostringstream{};
+      object_ss << std::hex << std::hash<Source>{}(source);
+      const auto object = object_ss.str();
+
+      ninja << "build $build_dir/" <<  object << ".o: cc " << source.path << "\n";
+      ninja << "  depfile = $build_dir/" << object << ".d\n";
+      ninja << "  fileflags = " << source.as_flags() << "\n\n";
+      objects.push_back(object);
+    }
+
+    ninja << "\nbuild $target: link ";
+    auto joined =
+        objects |
+        std::views::transform([](const std::string &obj) -> std::string {
+          return "$build_dir/" + obj + ".o";
+        }) |
+        std::views::join_with(' ');
+    for (const auto &part : joined) {
+      ninja << part;
+    }
+    ninja << "\n\n";
+
+    return ninja.str();
+  }
 
   auto into_compile_commands(const std::string_view& working_dir) -> json::JsonValue {
     std::vector<json::JsonValue> compile_commands{};
@@ -435,15 +692,19 @@ struct Project {
     }();
 
     for (const auto &source : sources) {
-      std::printf("Processing source: %s\n", source.data());
+      std::cout << std::format("Processing source: {}\n", source.path);
       auto fields = std::unordered_map<std::string_view, json::JsonValue>{};
       fields["directory"] = json::JsonValue(working_dir);
-      fields["file"] = json::JsonValue(source);
-      fields["arguments"] = json::JsonValue(std::vector<json::JsonValue>{
-          json::JsonValue(std::string_view("g++")), json::JsonValue(std::string_view("-c")),
-          json::JsonValue(std::string_view(source)), json::JsonValue(std::string_view("-o")),
-          json::JsonValue(std::string_view(std::string(source) + std::string(".o"))),
-          json::JsonValue(std::vector<json::JsonValue>(project_args))});
+      fields["file"] = json::JsonValue(source.path);
+      auto arguments = std::vector<json::JsonValue>{
+          json::JsonValue("g++"), json::JsonValue("-c"),
+          json::JsonValue(std::string_view(source.path)),
+          json::JsonValue(std::string_view("-o")),
+          json::JsonValue(std::string(source.path) + std::string(".o"))};
+      arguments.append_range(project_args);
+      arguments << source.as_flags();
+      fields["arguments"] = json::JsonValue(arguments);
+      fields["output"] = json::JsonValue(std::string(source.path) + ".o");
 
       compile_commands.push_back(json::JsonValue(json::JsonObject(fields)));
     }
@@ -452,6 +713,7 @@ struct Project {
     return compile_commands;
   }
 };
+
 static auto ninja_escape(std::string_view s) -> std::string {
   std::string out;
   out.reserve(s.size());
@@ -542,40 +804,263 @@ auto compile_commands_into_ninja(const json::JsonValue &compile_commands)
     if (auto args_field = obj.get_field("arguments")) {
       cmd = shell_join_arguments(args_field->get().as_array().value());
     } else if (auto command_field = obj.get_field("command")) {
-      cmd = command_field->get().as_string().value();
+      cmd = ninja_escape(command_field->get().as_string().value());
     } else {
       throw std::runtime_error(
           "compile_commands entry must contain either 'arguments' or 'command'");
     }
 
     ninja << "build " << ninja_escape(output) << ": cc " << ninja_escape(file) << "\n";
-    ninja << "  cmd = " << ninja_escape(cmd) << "\n\n";
+    ninja << "  cmd = " << cmd << "\n\n";
   }
 
+  ninja << "rule link\n";
+  ninja << "  command = g++ -fuse-ld=mold -o $out $in\n";
+
   std::cout << ninja.str();
   } else {
     throw std::runtime_error("compile_commands root must be an array");
   }
 }
 
+namespace libc {
+
+#include <spawn.h>
+#include <sys/wait.h>
+  
+}
+
+namespace command {
+
+
+  /// returns {child_fd, parent_fd}
+  auto piped_stdio(bool readable) -> std::pair<u32, u32> {
+    int fds[2];
+    if (::libc::pipe(fds) == -1) {
+      throw std::runtime_error("Failed to create pipe");
+    }
+
+    if (readable) {
+      // read end for child, write end for parent
+      return {static_cast<u32>(fds[0]), static_cast<u32>(fds[1])};
+    } else {
+      // write end for child, read end for parent
+      return {static_cast<u32>(fds[1]), static_cast<u32>(fds[0])};
+    }
+  }
+
+
+  enum class StdioStrategy {
+    Inherit,
+    Piped,
+    Fd,
+    Null,
+  };
+
+  struct StdioInherit : std::monostate {};
+  struct StdioPiped : std::monostate {};
+  // struct StdioNull : std::monostate {};
+  struct StdioFd {
+    u32 fd;
+
+    StdioFd(u32 fd) : fd(fd) {}
+  };
+
+  class Stdio {
+    StdioStrategy strategy;
+    std::optional<u32> fd_;
+
+  public:
+    Stdio(u32 fd) : strategy(StdioStrategy::Fd), fd_(fd) {}
+    Stdio(StdioFd stdio_fd) : strategy(StdioStrategy::Fd), fd_(stdio_fd.fd) {}
+    Stdio(StdioInherit) : strategy(StdioStrategy::Inherit), fd_(std::nullopt) {}
+    Stdio(StdioPiped) : strategy(StdioStrategy::Piped), fd_(std::nullopt) {}
+
+    auto operator=(u32 fd) -> Stdio & {
+      strategy = StdioStrategy::Fd;
+      fd_ = fd;
+      return *this;
+    }
+    auto operator=(StdioFd stdio_fd) -> Stdio & {
+      strategy = StdioStrategy::Fd;
+      fd_ = stdio_fd.fd;
+      return *this;
+    }
+    auto operator=(StdioInherit) -> Stdio & {
+      strategy = StdioStrategy::Inherit;
+      fd_ = std::nullopt;
+      return *this;
+    }
+    auto operator=(StdioPiped) -> Stdio & {
+      strategy = StdioStrategy::Piped;
+      fd_ = std::nullopt;
+      return *this;
+    }
+
+    auto fd() const -> std::optional<u32> {
+      if (strategy == StdioStrategy::Fd) {
+        return fd_;
+      } else {
+        return std::nullopt;
+      }
+    }
+
+    auto into_child_parent(bool readable) -> std::pair<Stdio, std::optional<u32>> {
+      switch (strategy) {
+      case StdioStrategy::Inherit:
+        return {StdioInherit{}, std::nullopt};
+      case StdioStrategy::Fd:
+        return {{StdioFd(fd_.value())}, std::nullopt};
+      case StdioStrategy::Piped: {
+        auto [child_fd, parent_fd] = piped_stdio(readable);
+        return {{StdioFd(child_fd)}, std::make_optional(parent_fd)};
+      }
+      default:
+        throw std::runtime_error("Invalid Stdio strategy");
+      }
+    }
+  };
+
+  class Process {
+    pid_t pid_;
+
+  public:
+    Process(pid_t pid) : pid_(pid) {}
+
+    auto pid() const -> pid_t {
+      return pid_;
+    }
+
+    auto wait() -> int {
+      int status;
+      if (::libc::waitpid(pid_, &status, 0) == -1) {
+        throw std::runtime_error("Failed to wait for child process");
+      }
+      return status;
+    }
+
+    auto send_signal(int signal) -> void {
+      if (::libc::kill(pid_, signal) == -1) {
+        throw std::runtime_error("Failed to send signal to child process");
+      }
+    }
+
+    auto kill() -> void {
+      send_signal(SIGKILL);
+    }
+
+  };
+
+  class Child : public Process {
+    std::optional<u32> stdout_fd{};
+
+  public:
+    Child(pid_t pid) : Process(pid) {}
+    Child(pid_t pid, std::optional<u32> stdout_fd) : Process(pid), stdout_fd(stdout_fd) {}
+
+  };
+class Command {
+  std::vector<std::string> args;
+  std::unordered_map<std::string, std::string> env;
+  std::string cmd;
+  std::string current_dir;
+  Stdio stdout{StdioInherit{}};
+
+public:
+  Command(std::string cmd) : cmd(std::move(cmd)) {}
+
+  auto with_arg(std::string arg) -> Command & {
+    args.push_back(std::move(arg));
+    return *this;
+  }
+
+  auto with_env(std::string key, std::string value) -> Command & {
+    env[std::move(key)] = std::move(value);
+    return *this;
+  }
+
+  auto with_current_dir(std::string dir) -> Command & {
+    current_dir = std::move(dir);
+    return *this;
+  }
+
+  auto spawn() -> std::variant<Child, std::error_code> {
+    std::vector<char *> argv;
+    argv.push_back(const_cast<char *>(cmd.c_str()));
+    for (const auto &arg : args) {
+      argv.push_back(const_cast<char *>(arg.c_str()));
+    }
+    argv.push_back(nullptr);
+
+    std::vector<std::string> env_strings;
+    std::vector<char *> envp;
+    for (const auto &[key, value] : env) {
+      env_strings.push_back(key + "=" + value);
+      envp.push_back(const_cast<char *>(env_strings.back().c_str()));
+    }
+    envp.push_back(nullptr);
+
+    auto [child_stdout, stdout_fd] = stdout.into_child_parent(false);
+
+    ::libc::posix_spawn_file_actions_t file_actions;
+    ::libc::posix_spawn_file_actions_init(&file_actions);
+    if (child_stdout.fd()) {
+      ::libc::posix_spawn_file_actions_adddup2(&file_actions, *stdout_fd, STDOUT_FILENO);
+    }
+
+    pid_t pid;
+    int result = ::libc::posix_spawnp(&pid, cmd.c_str(), &file_actions, nullptr, argv.data(), envp.data());
+    ::libc::posix_spawn_file_actions_destroy(&file_actions);
+
+    if (result != 0) {
+      return std::error_code(result, std::generic_category());
+    }
+
+    return Child{pid, stdout_fd};
+  }
+};
+}
+
 #include <fstream>
 #include <list>
+#include <ext/stdio_filebuf.h>
 
 auto main() -> int {
   std::printf("Hello, weave!\n");
 
   // Example usage
-  Project project("MyProject");
-  project.add_source("src/main.cc");
-  project.project_flags.append_range(std::list{"-g", "-Wall", "-Wextra", "--std=c++26", "-O3"});
+  Project project("Weave");
+  project.add_source("weave.cc");
+  auto std_mod = Module("std.cppm", "std");
+  std_mod.with_flag("--std=c++26")
+      .with_flag("-Wno-reserved-identifier")
+      .with_flag("-Wno-reserved-module-identifier")
+      .with_flag("-Wno-unused-command-line-argument")
+      .with_flag("-I/nix/store/wi8d6w3a8l82kppk060s7bjjw83601xi-gcc-16.1.0/"
+                 "include/c++/16.1.0/backward");
+  project.add_module(std_mod);
+  project.project_flags.append_range(
+      std::list{"-Wall", "-Wextra", "--std=c++26", "-O1"});
 
-  auto compile_commands_json = project.into_compile_commands("/var/code/cxx/loom/");
+  const auto ninja = project.into_ninja_commands();
+  {
 
+    std::ofstream os("build.ninja");
+    os << ninja;
+    os.close();
 
-  std::cout << compile_commands_json << std::endl;
-  // std::ofstream os("compile_commands.json");
-  // os << compile_commands_json;
-  // os.close();
+    command::Command cmd("ninja");
+    cmd.with_arg("-f").with_arg("build.ninja");
+    cmd.spawn().visit(overloads{
+        [](command::Child child) {
+          std::printf("Spawned ninja with PID %d\n", child.pid());
+          int status = child.wait();
+          std::printf("Ninja exited with status %d\n", status);
+        },
+        [](std::error_code ec) {
+          std::fprintf(stderr, "Failed to spawn ninja: %s\n", ec.message().c_str());
+        }});
+  }
 
   return 0;
 }