feat: support package-owned ldflags

Add package-owned ldflags support and prepare mcpp 0.0.38.

Author: Sunrisepeak

CHANGELOG.md

@@ -3,6 +3,14 @@
 > 本文件追踪 `mcpp-community/mcpp` 公开仓的版本演进。
 > 格式参考 [Keep a Changelog](https://keepachangelog.com/zh-CN/1.1.0/)。
 
+## [0.0.38] — 2026-05-31
+
+### 新增
+
+- 支持包描述拥有自己的 `ldflags`,依赖包声明的链接参数会随包源码编译
+  一起进入最终链接命令,消费方项目不再需要手动补齐第三方 C/C++
+  库的私有链接参数。
+
 ## [0.0.37] — 2026-05-31
 
 ### 修复

README.md

@@ -142,7 +142,7 @@ import mcpplibs.cmdline;
 - Ninja 后端：自动生成 build.ninja，并行编译
 - compile_commands.json 自动生成（clangd / ccls 即用）
 - C 语言一等支持：`.c` 文件自动检测，混合 C/C++ 项目
-- 用户自定义 cflags / cxxflags / c_standard
+- 用户自定义 cflags / cxxflags / ldflags / c_standard
 
 </details>
 

docs/05-mcpp-toml.md

@@ -73,6 +73,7 @@ include_dirs = ["include", "third_party/include"]  # 头文件搜索路径
 c_standard   = "c11"              # C 源文件的标准(默认 c11)
 cflags       = ["-DFOO=1"]        # 额外 C 编译参数
 cxxflags     = ["-DBAR=2"]        # 额外 C++ 编译参数
+ldflags      = ["-lfoo"]          # 额外链接参数
 static_stdlib = true               # 静态链接 libstdc++(默认 true)
 ```
 

mcpp.toml

@@ -1,6 +1,6 @@
 [package]
 name        = "mcpp"
-version     = "0.0.37"
+version     = "0.0.38"
 description = "Modern C++ build & package management tool"
 license     = "Apache-2.0"
 authors     = ["mcpp-community"]

src/build/flags.cppm

@@ -56,6 +56,26 @@ std::string escape_path(const std::filesystem::path& p) {
     return out;
 }
 
+std::string normalize_ldflag(const std::filesystem::path& root, const std::string& flag) {
+    auto absolute_path = [&](std::string_view raw) {
+        std::filesystem::path p{std::string(raw)};
+        if (p.is_absolute() || raw.starts_with("$")) return p;
+        return root / p;
+    };
+
+    if (flag.starts_with("-L") && flag.size() > 2) {
+        return "-L" + escape_path(absolute_path(std::string_view(flag).substr(2)));
+    }
+
+    constexpr std::string_view rpathPrefix = "-Wl,-rpath,";
+    if (flag.starts_with(rpathPrefix) && flag.size() > rpathPrefix.size()) {
+        return std::string(rpathPrefix)
+             + escape_path(absolute_path(std::string_view(flag).substr(rpathPrefix.size())));
+    }
+
+    return flag;
+}
+
 }  // namespace
 
 CompileFlags compute_flags(const BuildPlan& plan) {
@@ -192,6 +212,11 @@ CompileFlags compute_flags(const BuildPlan& plan) {
     };
     std::string user_cxxflags = join(plan.manifest.buildConfig.cxxflags);
     std::string user_cflags = join(plan.manifest.buildConfig.cflags);
+    std::string user_ldflags;
+    for (auto const& flag : plan.manifest.buildConfig.ldflags) {
+        user_ldflags += ' ';
+        user_ldflags += normalize_ldflag(plan.projectRoot, flag);
+    }
 
     // C standard
     std::string c_std =
@@ -257,12 +282,12 @@ CompileFlags compute_flags(const BuildPlan& plan) {
     }
 
     if constexpr (mcpp::platform::is_windows) {
-        f.ld = "";
+        f.ld = user_ldflags;
     } else if constexpr (mcpp::platform::needs_explicit_libcxx) {
-        f.ld = std::format("{}{}{} -lc++", full_static, static_stdlib, b_flag);
+        f.ld = std::format("{}{}{} -lc++{}", full_static, static_stdlib, b_flag, user_ldflags);
     } else {
-        f.ld = std::format("{}{}{}{}{}{}", full_static, static_stdlib, link_toolchain_flags, b_flag,
-                           runtime_dirs, payload_ld);
+        f.ld = std::format("{}{}{}{}{}{}{}", full_static, static_stdlib, link_toolchain_flags, b_flag,
+                           runtime_dirs, payload_ld, user_ldflags);
     }
 
     return f;

src/cli.cppm

@@ -597,6 +597,10 @@ std::string canonical_compile_flags(const mcpp::manifest::Manifest& m) {
         s += " cxxflag:";
         s += flag;
     }
+    for (auto const& flag : m.buildConfig.ldflags) {
+        s += " ldflag:";
+        s += flag;
+    }
     return s;
 }
 
@@ -623,6 +627,10 @@ std::string canonical_package_build_metadata(
             s += " cxxflag:";
             s += flag;
         }
+        for (auto const& flag : pkg.manifest.buildConfig.ldflags) {
+            s += " ldflag:";
+            s += flag;
+        }
         for (auto const& [path, content] : pkg.manifest.buildConfig.generatedFiles) {
             s += " genfile:";
             s += path.generic_string();
@@ -1541,6 +1549,7 @@ prepare_build(bool print_fingerprint,
         std::string source;             // "version" | "path" | "git" — for type-clash check
         std::size_t depIndex = 0;       // index into dep_manifests/packages-1 (for in-place re-fetch)
         std::vector<std::filesystem::path> includeDirsAdded;  // entries appended to m->buildConfig.includeDirs by this dep
+        std::vector<std::string> linkFlagsAdded;  // entries appended to m->buildConfig.ldflags by this dep
     };
     std::map<ResolvedKey, ResolvedRecord> resolved;
 
@@ -1824,6 +1833,48 @@ prepare_build(bool print_fingerprint,
         }
     };
 
+    auto normalizeDepLdflag = [](const std::filesystem::path& depRoot,
+                                 const std::string& flag) {
+        auto absolute_path = [&](std::string_view raw) {
+            std::filesystem::path p{std::string(raw)};
+            if (p.is_absolute() || raw.starts_with("$")) return p;
+            return depRoot / p;
+        };
+
+        if (flag.starts_with("-L") && flag.size() > 2) {
+            return "-L" + absolute_path(std::string_view(flag).substr(2)).string();
+        }
+
+        constexpr std::string_view rpathPrefix = "-Wl,-rpath,";
+        if (flag.starts_with(rpathPrefix) && flag.size() > rpathPrefix.size()) {
+            return std::string(rpathPrefix)
+                 + absolute_path(std::string_view(flag).substr(rpathPrefix.size())).string();
+        }
+
+        return flag;
+    };
+
+    auto propagateLinkFlags = [&](const std::filesystem::path& depRoot,
+                                  const mcpp::manifest::Manifest& depManifest)
+        -> std::vector<std::string>
+    {
+        std::vector<std::string> added;
+        for (auto const& flag : depManifest.buildConfig.ldflags) {
+            auto normalized = normalizeDepLdflag(depRoot, flag);
+            m->buildConfig.ldflags.push_back(normalized);
+            added.push_back(std::move(normalized));
+        }
+        return added;
+    };
+
+    auto removeLinkFlags = [&](const std::vector<std::string>& flags) {
+        auto& ldflags = m->buildConfig.ldflags;
+        for (auto const& flag : flags) {
+            auto pos = std::find(ldflags.begin(), ldflags.end(), flag);
+            if (pos != ldflags.end()) ldflags.erase(pos);
+        }
+    };
+
     // Stage a dep's source files into a fresh directory, rewriting their
     // module / import declarations against `rename`. Used by the multi-
     // version mangling fallback (Level 1) so two cross-major copies of
@@ -2065,6 +2116,7 @@ prepare_build(bool print_fingerprint,
                     });
                     packages.push_back({secStage, *dep_manifests.back()});
                     auto added = propagateIncludeDirs(secStage, *dep_manifests.back());
+                    auto linkFlagsAdded = propagateLinkFlags(secStage, *dep_manifests.back());
 
                     ResolvedKey mangledKey{key.ns, mangled};
                     resolved[mangledKey] = ResolvedRecord{
@@ -2074,6 +2126,7 @@ prepare_build(bool print_fingerprint,
                         .source            = "version",
                         .depIndex          = dep_manifests.size() - 1,
                         .includeDirsAdded  = std::move(added),
+                        .linkFlagsAdded    = std::move(linkFlagsAdded),
                     };
 
                     mcpp::ui::info("Mangled",
@@ -2136,7 +2189,9 @@ prepare_build(bool print_fingerprint,
                 }
 
                 removeIncludeDirs(it->second.includeDirsAdded);
+                removeLinkFlags(it->second.linkFlagsAdded);
                 auto added = propagateIncludeDirs(newRoot, newManifest);
+                auto linkFlagsAdded = propagateLinkFlags(newRoot, newManifest);
 
                 // Replace in dep_manifests + packages. depIndex is the slot
                 // in dep_manifests; packages = [main, dep_0, dep_1, …], so
@@ -2147,6 +2202,7 @@ prepare_build(bool print_fingerprint,
 
                 it->second.version            = *merged;
                 it->second.includeDirsAdded   = std::move(added);
+                it->second.linkFlagsAdded     = std::move(linkFlagsAdded);
                 if (it->second.depIndex < dep_cache_identities.size())
                     dep_cache_identities[it->second.depIndex].version = *merged;
 
@@ -2284,6 +2340,7 @@ prepare_build(bool print_fingerprint,
         // expansion against dep_root) — stash it so a SemVer merge can
         // evict these entries on a re-fetch.
         auto includeDirsAdded = propagateIncludeDirs(dep_root, *dep_manifest);
+        auto linkFlagsAdded = propagateLinkFlags(dep_root, *dep_manifest);
 
         // Move the manifest into stable storage so we can later look it up
         // by depIndex (the SemVer merger needs to overwrite the slot).
@@ -2307,6 +2364,7 @@ prepare_build(bool print_fingerprint,
             .source            = sourceKind,
             .depIndex          = dep_manifests.size() - 1,
             .includeDirsAdded  = std::move(includeDirsAdded),
+            .linkFlagsAdded    = std::move(linkFlagsAdded),
         };
 
         // Recurse: the dep's own [dependencies] become new worklist items.

src/manifest.cppm

@@ -91,6 +91,7 @@ struct BuildConfig {
     // Empty cStandard → backend default ("c11" today).
     std::vector<std::string>           cflags;
     std::vector<std::string>           cxxflags;
+    std::vector<std::string>           ldflags;
     std::string                         cStandard;
 };
 
@@ -628,6 +629,7 @@ std::expected<Manifest, ManifestError> parse_string(std::string_view content,
     if (auto v = doc->get_bool("build.static_stdlib")) m.buildConfig.staticStdlib = *v;
     if (auto v = doc->get_string_array("build.cflags"))   m.buildConfig.cflags   = *v;
     if (auto v = doc->get_string_array("build.cxxflags")) m.buildConfig.cxxflags = *v;
+    if (auto v = doc->get_string_array("build.ldflags"))  m.buildConfig.ldflags  = *v;
     if (auto v = doc->get_string("build.c_standard"))     m.buildConfig.cStandard = *v;
 
     // [lib] — library root convention (cargo-style).
@@ -1396,18 +1398,19 @@ synthesize_from_xpkg_lua(std::string_view luaContent,
             }
             cur.consume('}');
         }
-        else if (key == "cflags" || key == "cxxflags") {
+        else if (key == "cflags" || key == "cxxflags" || key == "ldflags") {
             // `{ "-Dfoo", "-Wall", ... }` — appended to the per-rule baseline
             // by ninja_backend. cflags goes to the C rule (.c files), cxxflags
-            // to C++ rule (.cpp/.cc/.cxx/.cppm).
+            // to C++ rule (.cpp/.cc/.cxx/.cppm), ldflags to link commands.
             if (!cur.consume('{')) {
                 return std::unexpected(ManifestError{
                     std::format("expected '{{' after `{} =`", key),
                     m.sourcePath, 0, 0});
             }
             cur.skip_ws_and_comments();
             auto& target = (key == "cflags")
-                ? m.buildConfig.cflags : m.buildConfig.cxxflags;
+                ? m.buildConfig.cflags
+                : (key == "cxxflags" ? m.buildConfig.cxxflags : m.buildConfig.ldflags);
             while (!cur.eof() && cur.peek() != '}') {
                 auto s = cur.read_string();
                 if (!s.empty()) target.push_back(std::move(s));

src/toolchain/fingerprint.cppm

@@ -18,7 +18,7 @@ import mcpp.toolchain.detect;
 
 export namespace mcpp::toolchain {
 
-inline constexpr std::string_view MCPP_VERSION = "0.0.37";
+inline constexpr std::string_view MCPP_VERSION = "0.0.38";
 
 struct FingerprintInputs {
     Toolchain                       toolchain;

tests/e2e/54_package_owned_ldflags.sh

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+# requires: gcc
+# Package-owned ldflags: a dependency can declare link flags that are applied
+# when the consumer binary is linked.
+set -e
+
+TMP=$(mktemp -d)
+trap "rm -rf $TMP" EXIT
+
+cd "$TMP"
+mkdir -p native depLink app/src
+
+cat > native/answer.c <<'EOF'
+int dep_link_answer(void) {
+    return 42;
+}
+EOF
+
+gcc -c native/answer.c -o native/answer.o
+ar rcs native/libanswer.a native/answer.o
+NATIVE_DIR="$(pwd)/native"
+
+cat > depLink/mcpp.toml <<EOF
+[package]
+name    = "depLink"
+version = "0.1.0"
+
+[build]
+ldflags = ["-L${NATIVE_DIR}", "-lanswer"]
+EOF
+
+cat > app/src/main.cpp <<'EOF'
+extern "C" int dep_link_answer(void);
+
+int main() {
+    return dep_link_answer() == 42 ? 0 : 1;
+}
+EOF
+
+cat > app/mcpp.toml <<'EOF'
+[package]
+name    = "app"
+version = "0.1.0"
+
+[build]
+sources = ["src/*.cpp"]
+
+[targets.app]
+kind = "bin"
+main = "src/main.cpp"
+
+[dependencies.depLink]
+path = "../depLink"
+EOF
+
+cd app
+"$MCPP" build > build.log 2>&1 || {
+    cat build.log
+    echo "build failed"
+    exit 1
+}
+
+"$MCPP" run > run.log 2>&1 || {
+    cat run.log
+    echo "run failed"
+    exit 1
+}
+
+ninja_file="$(find target -name build.ninja | head -1)"
+[[ -n "$ninja_file" ]] || {
+    echo "no build.ninja generated"
+    exit 1
+}
+
+grep -q -- "-L${NATIVE_DIR}" "$ninja_file" || {
+    echo "dep -L flag missing from build.ninja"
+    cat "$ninja_file"
+    exit 1
+}
+grep -q -- "-lanswer" "$ninja_file" || {
+    echo "dep -l flag missing from build.ninja"
+    cat "$ninja_file"
+    exit 1
+}
+
+echo "OK"

tests/unit/test_manifest.cpp

@@ -153,6 +153,7 @@ version = "0.1.0"
 sources    = ["src/**/*.{cppm,c}"]
 cflags     = ["-Wall", "-DFOO=1"]
 cxxflags   = ["-Wextra"]
+ldflags    = ["-lfoo", "-Wl,--as-needed"]
 c_standard = "c11"
 [targets.x]
 kind = "lib"
@@ -164,10 +165,13 @@ kind = "lib"
     EXPECT_EQ(m->buildConfig.cflags[1], "-DFOO=1");
     ASSERT_EQ(m->buildConfig.cxxflags.size(), 1u);
     EXPECT_EQ(m->buildConfig.cxxflags[0], "-Wextra");
+    ASSERT_EQ(m->buildConfig.ldflags.size(), 2u);
+    EXPECT_EQ(m->buildConfig.ldflags[0], "-lfoo");
+    EXPECT_EQ(m->buildConfig.ldflags[1], "-Wl,--as-needed");
     EXPECT_EQ(m->buildConfig.cStandard, "c11");
 }
 
-TEST(SynthesizeFromXpkgLua, CflagsCxxflagsAndCStandard) {
+TEST(SynthesizeFromXpkgLua, CflagsCxxflagsLdflagsAndCStandard) {
     constexpr auto src = R"(
 package = {
     spec = "1",
@@ -177,6 +181,7 @@ package = {
         sources    = { "*/src/*.c" },
         cflags     = { "-Wall", "-Dunused" },
         cxxflags   = { "-Wextra" },
+        ldflags    = { "-ltinyc" },
         c_standard = "c11",
         targets    = { ["tinyc"] = { kind = "lib" } },
     },
@@ -189,6 +194,8 @@ package = {
     EXPECT_EQ(m->buildConfig.cflags[1], "-Dunused");
     ASSERT_EQ(m->buildConfig.cxxflags.size(), 1u);
     EXPECT_EQ(m->buildConfig.cxxflags[0], "-Wextra");
+    ASSERT_EQ(m->buildConfig.ldflags.size(), 1u);
+    EXPECT_EQ(m->buildConfig.ldflags[0], "-ltinyc");
     EXPECT_EQ(m->buildConfig.cStandard, "c11");
     ASSERT_EQ(m->modules.sources.size(), 1u);
     EXPECT_EQ(m->modules.sources[0], "*/src/*.c");