feat: 添加 mp-units 2.5.0 模块包（LLVM） (#515)

复用上游 mp_units.core / mp_units.systems / mp_units 三个模块，安装钩子仅将接口复制为 .cppm。
linux 要求 libc++：GCC 16.1 导入模块报 recursive lazy load（mpusz/mp-units#717），CI gcc 腿跳过该成员。
关闭实验性自然单位（LLVM 22 约束失败）。

Co-authored-by: HikariTish <helanlordts@163.com>

Author: Sunrisepeak

.github/workflows/validate.yml

@@ -1456,6 +1456,22 @@ jobs:
             mine="${kept# }"
           fi
 
+          # `mp-units-module`: the reverse case. `mpusz.mp-units` requires
+          # libc++ on linux because GCC 16.1 cannot import its modules
+          # (`recursive lazy load`, mpusz/mp-units#717), so the gcc leg would
+          # only reach that refusal. Lift once xim ships a GCC that works.
+          if [ "${{ matrix.platform }}" = "linux" ] && [ "${{ matrix.toolchain }}" = "default" ]; then
+            kept=""
+            for m in $mine; do
+              case "$m" in
+                mp-units-module)
+                  echo "skipping '$m' on the gcc leg: the package requires libc++" ;;
+                *) kept="$kept $m" ;;
+              esac
+            done
+            mine="${kept# }"
+          fi
+
           echo "MEMBERS=$mine" >> "$GITHUB_ENV"
           echo "shard ${{ matrix.shard }}/${{ matrix.shards }}: ${mine:-<none>}"
 

docs/descriptor-examples.md

@@ -49,3 +49,4 @@ in the [root README](../README.md#reference-examples).
 | C++23 module, upstream's own unit | [`khronos.vulkan-hpp`](../pkgs/k/khronos.vulkan-hpp.lua) (Vulkan-Hpp 1.4.357.0 — Khronos generates `vulkan.cppm` / `vulkan_video.cppm` into every Vulkan-Headers release, so `sources` names the two units and NOTHING is authored here; the payload is the same tarball, URL and sha256 as `compat.vulkan-headers`, which is what makes the module and the headers it includes impossible to skew. `import_std = true` is forced by the unit's own unconditional `export import std;`. No `include_dirs`: the headers arrive with the `compat.vulkan` dependency, which is also what satisfies the STATIC dispatcher's direct calls at link — depending on headers alone gives a package that compiles and then fails at every consumer's link. Module names stay upstream's `vulkan` / `vulkan_video`, never `khronos.vulkan`. The second unit `import`s the first and mcpp orders the pair from the scan, which `tests/examples/vulkan-hpp-module/tests/video.cpp` is the regression for) |
 | C++23 module, upstream's CPU partitions | [`taskflow.taskflow`](../pkgs/t/taskflow.taskflow.lua) (Taskflow 4.1.0, `import tf;`; reuses the four upstream CPU module units and omits the competing CUDA entry point. The checked install hook removes two nonexistent exports, moves the umbrella include/version export into core and imports core first for GCC, and supplies `<algorithm>` to utility for libc++. Only three module files are patched; headers and scheduler implementation stay upstream. No fork; consumers use `tf::version()` because macros are not exported) |
 | C++23 module, upstream asynchronous logging | [`odygrd.quill`](../pkgs/o/odygrd.quill.lua) (Quill 13.0.0, upstream experimental `quill` module; the checked install hook generates `.cppm` from `src/quill.cc`, guards x86 intrinsics by target architecture and includes Apple Mach headers in the global module fragment. Consumers use `import std; import quill;` and the macro-free API, or define `QUILL_USE_MODULE` and include `quill/LogMacros.h` for logging macros. Bundled fmt needs no separate dependency; Linux links with `-pthread`. Multi-TU logger identity, worker-thread output, formatting and filtering are tested) |
+| C++23 modules, upstream units | [`mpusz.mp-units`](../pkgs/m/mpusz.mp-units.lua) (2.5.0; upstream `mp_units.core`, `mp_units.systems` and `mp_units`, copied verbatim to `.cppm` by the install hook so Clang treats them as interfaces. `import std`, `std::format`, runtime contracts off, experimental natural units off. Linux requires libc++ (LLVM): GCC 16.1 fails to import the module with `recursive lazy load`, mpusz/mp-units#717) |

docs/zh/descriptor-examples.md

@@ -47,3 +47,4 @@
 | C++23 module,上游自带单元 | [`khronos.vulkan-hpp`](../../pkgs/k/khronos.vulkan-hpp.lua)(Vulkan-Hpp 1.4.357.0 —— Khronos 把 `vulkan.cppm` / `vulkan_video.cppm` 生成进每个 Vulkan-Headers release,所以 `sources` 点名这两个单元即可,本仓**不写一行**包装体;载荷与 `compat.vulkan-headers` 是同一份 tarball、同一个 URL 与 sha256,这让模块与它 include 的头不可能错配。`import_std = true` 由单元自身无条件的 `export import std;` 决定。不声明 `include_dirs`:头随 `compat.vulkan` 依赖到达,而该依赖同时满足静态 dispatcher 在链接期的直接调用 —— 只依赖头会得到一个「能编译、每个消费者都链接失败」的包。模块名保持上游的 `vulkan` / `vulkan_video`,绝不写成 `khronos.vulkan`。第二个单元 `import` 第一个,顺序由 mcpp 扫描决定,`tests/examples/vulkan-hpp-module/tests/video.cpp` 就是这条的回归)|
 | C++23 module，上游 CPU 分区 | [`taskflow.taskflow`](../../pkgs/t/taskflow.taskflow.lua)（Taskflow 4.1.0，`import tf;`；复用上游四个 CPU 模块单元，排除提供同名主模块的 CUDA 入口。安装钩子逐项校验匹配次数：移除两个不存在的导出，将总头文件及版本导出移至 core 并优先导入 core 以兼容 GCC，为 utility 补 `<algorithm>` 以兼容 libc++。仅适配三个模块文件，头文件和调度实现保持上游原样，无独立 fork；宏不随模块导出，版本查询使用 `tf::version()`） |
 | C++23 module，上游异步日志 | [`odygrd.quill`](../../pkgs/o/odygrd.quill.lua)（Quill 13.0.0，上游实验性 `quill` 模块；安装钩子以 `src/quill.cc` 生成 `.cppm`，精确适配 x86 intrinsic 的架构条件与 Apple Mach 头的全局模块归属。消费者使用 `import std; import quill;` 和无宏 API，或定义 `QUILL_USE_MODULE` 并包含 `quill/LogMacros.h` 使用日志宏。自带 fmt，无需额外依赖；Linux 链接使用 `-pthread`。测试覆盖多 TU logger 身份、工作线程输出、格式化和过滤） |
+| C++23 模块，上游自带单元 | [`mpusz.mp-units`](../../pkgs/m/mpusz.mp-units.lua)（2.5.0；复用 `mp_units.core`、`mp_units.systems`、`mp_units`，安装钩子将接口原样复制为 `.cppm` 供 Clang 识别。使用 `import std` 与 `std::format`，关闭运行时契约和实验性自然单位。Linux 要求 libc++（LLVM）：GCC 16.1 导入模块时报 `recursive lazy load`，见 mpusz/mp-units#717） |

mcpp.toml

@@ -147,6 +147,7 @@ members = [
     "tests/examples/sqlitecpp",
     "tests/examples/taskflow-module",
     "tests/examples/quill-module",
+    "tests/examples/mp-units-module",
     "tests/examples/tinyhttps",
     "tests/examples/usockets",
     "tests/examples/opencl",

pkgs/m/mpusz.mp-units.lua

@@ -0,0 +1,77 @@
+package = {
+    spec = "1",
+    namespace = "mpusz",
+    name = "mp-units",
+    description = "Physical quantities and units through the upstream mp_units C++ modules",
+    licenses = { "MIT" },
+    repo = "https://github.com/mpusz/mp-units",
+    type = "package",
+    xpm = {
+        linux = {
+            ["2.5.0"] = {
+                url = "https://github.com/mpusz/mp-units/archive/refs/tags/v2.5.0.tar.gz",
+                sha256 = "a6bd48bee699f11f0ed5b04b8c5006d15f76e6d898e058db3880554d2e47a400",
+            },
+        },
+        macosx = {
+            ["2.5.0"] = {
+                url = "https://github.com/mpusz/mp-units/archive/refs/tags/v2.5.0.tar.gz",
+                sha256 = "a6bd48bee699f11f0ed5b04b8c5006d15f76e6d898e058db3880554d2e47a400",
+            },
+        },
+        windows = {
+            ["2.5.0"] = {
+                url = "https://github.com/mpusz/mp-units/archive/refs/tags/v2.5.0.tar.gz",
+                sha256 = "a6bd48bee699f11f0ed5b04b8c5006d15f76e6d898e058db3880554d2e47a400",
+            },
+        },
+    },
+    mcpp = {
+        language = "c++23",
+        import_std = true,
+        modules = { "mp_units.core", "mp_units.systems", "mp_units" },
+        include_dirs = { "*/src/core/include", "*/src/systems/include" },
+        -- 上游 import std 配置：标准格式化、关闭运行时契约；自然单位为实验特性，LLVM 22 下约束失败
+        defines = {
+            "MP_UNITS_IMPORT_STD",
+            "MP_UNITS_API_STD_FORMAT=1",
+            "MP_UNITS_API_CONTRACTS=0",
+            "MP_UNITS_API_NATURAL_UNITS=0",
+        },
+        sources = {
+            "*/src/core/mp-units-core.cppm",
+            "*/src/systems/mp-units-systems.cppm",
+            "*/src/mp-units.cppm",
+        },
+        -- 两个上游接口的 std 导入受 MP_UNITS_IMPORT_STD 守卫
+        scan_overrides = {
+            ["*/src/core/mp-units-core.cppm"] = {
+                provides = { "mp_units.core" }, imports = { "std" },
+            },
+            ["*/src/systems/mp-units-systems.cppm"] = {
+                provides = { "mp_units.systems" }, imports = { "mp_units.core", "std" },
+            },
+        },
+        targets = { ["mp-units"] = { kind = "lib" } },
+        deps = {},
+        linux = {
+            -- 暂不支持 GCC：GCC 16.1 导入该模块时报 recursive lazy load（mpusz/mp-units#717）
+            requires = { "mcpp:c++-abi=libc++" },
+        },
+    },
+}
+
+import("xim.libxpkg.pkginfo")
+
+function install()
+    local wrap = "mp-units-" .. pkginfo.version()
+    -- 上游接口以 .cpp 命名，复制为 .cppm 供 Clang 识别为模块接口
+    for _, relative in ipairs({ "src/core/mp-units-core", "src/systems/mp-units-systems", "src/mp-units" }) do
+        os.cp(path.join(wrap, relative .. ".cpp"), path.join(wrap, relative .. ".cppm"))
+    end
+    local prefix = pkginfo.install_dir()
+    os.tryrm(prefix)
+    os.mkdir(prefix)
+    os.mv(wrap, path.join(prefix, wrap))
+    return true
+end

tests/examples/mp-units-module/mcpp.toml

@@ -0,0 +1,9 @@
+[package]
+name = "mp-units-module-tests"
+version = "0.1.0"
+
+[indices]
+mpusz = { path = "../../.." }
+
+[dependencies.mpusz]
+mp-units = "2.5.0"

tests/examples/mp-units-module/src/quantity_bridge.cpp

@@ -0,0 +1,9 @@
+import std;
+import mp_units.core;
+import mp_units.systems;
+
+#include "quantity_bridge.h"
+
+distance add_distance(distance left, distance right) {
+    return left + right;
+}

tests/examples/mp-units-module/src/quantity_bridge.h

@@ -0,0 +1,5 @@
+#pragma once
+
+using distance = mp_units::quantity<mp_units::si::metre, int>;
+
+distance add_distance(distance left, distance right);

tests/examples/mp-units-module/tests/units.cpp

@@ -0,0 +1,22 @@
+import std;
+import mp_units;
+
+#include "../src/quantity_bridge.h"
+
+using namespace mp_units;
+using namespace mp_units::si::unit_symbols;
+
+template<class Left, class Right>
+concept Addable = requires(Left left, Right right) { left + right; };
+
+static_assert(1 * km == 1000 * m);
+static_assert(!Addable<decltype(1 * m), decltype(1 * s)>);
+static_assert((120 * km / (2 * h)).numerical_value_in(km / h) == 60);
+static_assert(quantity{std::chrono::minutes{2}} == 120 * s);
+
+int main() {
+    if (add_distance(20 * m, 22 * m) != 42 * m) return 1;
+    if (std::format("{}", 42 * m) != "42 m") return 2;
+    if (std::format("{}", 2 * ohm) != "2 \xce\xa9") return 3;
+    return 0;
+}