feat: feature-gated dep sources + mcpp add --dev — fix #168 gtest_main (v0.0.65) (#169)

Sunrisepeak · web-flow · commit 0f96b8254792 · 2026-06-25T14:25:50.000+08:00
* feat: feature-gated dependency sources + mcpp add --dev (fix #168 gtest_main) #168: gtest as a regular dependency injected gtest_main.o (its own main) into a `mcpp build` app, colliding with the app's main (LNK2005 / duplicate symbol). Generic fix — feature-gated sources: - A dependency descriptor may declare `[mcpp].features.<name>.sources`; a source listed there is EXCLUDED from the default build and only compiled/linked when that feature is active for the dep (`dep = { version, features=["name"] }`). - gtest descriptor (mcpp-index) puts gtest_main.cc behind the `main` feature → default `gtest = "1.15.2"` links framework only (no main collision); opt in with `features=["main"]`. Reuses the existing feature activation; new effect is "feature → sources" (manifest.cppm synthesize + prepare.cppm). - Gating applies only in build mode (!includeDevDeps); `mcpp test` keeps the dev-dependency main-detection track (0.0.64) unchanged — the two tracks stay decoupled. Descriptor keeps gtest_main.cc in base `sources` too, so OLD mcpp (ignores `features`) is unaffected (verified). mcpp add --dev <pkg> → writes [dev-dependencies] (was missing). - unit: SynthesizeFromXpkgLua.FeatureGatedSources - e2e: 79_gtest_regular_dep_feature_main.sh (#168 sentinel + opt-in + add --dev) - release.yml: default xlings 0.4.58 -> 0.4.60 (cache key bumped) - bump 0.0.64 -> 0.0.65 - design: .agents/docs/2026-06-25-gtest-main-feature-and-add-dev-design.md * test(e2e): 79 use portable newest-build.ninja (ls -t), not GNU find -printf macOS BSD find lacks -printf → nj came back empty → false 'gtest-all not linked'. Functionality was fine (78 passed, build succeeded). Use find | xargs ls -t.
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
@@ -86,17 +86,17 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~/.xlings
-          key: xlings-${{ runner.os }}-release-xl0448-${{ hashFiles('.xlings.json') }}
+          key: xlings-${{ runner.os }}-release-xl0460-${{ hashFiles('.xlings.json') }}
           restore-keys: |
-            xlings-${{ runner.os }}-release-xl0448-
+            xlings-${{ runner.os }}-release-xl0460-
 
       - name: Bootstrap mcpp via xlings
         env:
           XLINGS_NON_INTERACTIVE: '1'
           # Pin xlings to a known-good version. The upstream install
           # script always grabs `latest` (no version override), so we
           # download + self-install manually to avoid broken releases.
-          XLINGS_VERSION: '0.4.58'
+          XLINGS_VERSION: '0.4.60'
         run: |
           if [ ! -x "$HOME/.xlings/subos/default/bin/xlings" ]; then
             tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
@@ -281,7 +281,7 @@ jobs:
       - name: Bootstrap mcpp via xlings (latest 0.4.58)
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '0.4.58'
+          XLINGS_VERSION: '0.4.60'
         run: |
           tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
           curl -fsSL -o "/tmp/${tarball}" \
@@ -410,14 +410,14 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~/.xlings
-          key: xlings-macos15-release-xl0448-${{ hashFiles('.xlings.json') }}
+          key: xlings-macos15-release-xl0460-${{ hashFiles('.xlings.json') }}
           restore-keys: |
-            xlings-macos15-release-xl0448-
+            xlings-macos15-release-xl0460-
 
       - name: Bootstrap mcpp via xlings
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '0.4.58'
+          XLINGS_VERSION: '0.4.60'
         run: |
           if [ ! -x "$HOME/.xlings/subos/default/bin/xlings" ]; then
             WORK=$(mktemp -d)
@@ -591,15 +591,15 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~\.xlings
-          key: xlings-${{ runner.os }}-release-xl0448-${{ hashFiles('.xlings.json') }}
+          key: xlings-${{ runner.os }}-release-xl0460-${{ hashFiles('.xlings.json') }}
           restore-keys: |
-            xlings-${{ runner.os }}-release-xl0448-
+            xlings-${{ runner.os }}-release-xl0460-
 
       - name: Bootstrap mcpp via xlings
         shell: bash
         env:
           XLINGS_NON_INTERACTIVE: '1'
-          XLINGS_VERSION: '0.4.58'
+          XLINGS_VERSION: '0.4.60'
         run: |
           WORK=$(mktemp -d)
           zipfile="xlings-${XLINGS_VERSION}-windows-x86_64.zip"
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,6 +3,35 @@
 > 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/)。
 
+## [0.0.65] — 2026-06-25
+
+### 修复
+
+- **`mcpp add gtest` + `mcpp build` 报 `duplicate symbol: main` / `LNK2005`**(#168):
+  gtest 作为**常规依赖**时,其 `gtest_main.cc`(自带 main)被链进应用,与应用自身的
+  main 冲突。修复采用**通用的「feature 门控源」机制**:依赖描述符可声明
+  `[mcpp].features.<名>.sources`,被某 feature 列出的源**默认不编译/链接**,仅在该
+  feature 被请求(`dep = { version="…", features=["…"] }`)时纳入。gtest 描述符把
+  `gtest_main.cc` 归入 `main` feature → **默认只链框架,不再撞 main**;需要 gtest 提供
+  main 时 `gtest = { version="1.15.2", features=["main"] }` 显式开启。
+  门控仅作用于 `mcpp build`;`mcpp test` 保持既有的 dev 依赖 main 检测(0.0.64)不变。
+  详见 `.agents/docs/2026-06-25-gtest-main-feature-and-add-dev-design.md`。
+
+### 新增
+
+- **`mcpp add --dev <pkg>`**:把依赖写入 `[dev-dependencies]`(测试专属,如 gtest;
+  由 `mcpp test` 消费,不链进 `mcpp build` 的应用)。
+
+### 测试
+
+- 单元 `SynthesizeFromXpkgLua.FeatureGatedSources`(描述符 feature 门控源解析);
+  e2e `79_gtest_regular_dep_feature_main.sh`(#168 哨兵 + `features=["main"]` opt-in +
+  `add --dev`)。
+
+### CI
+
+- release workflow 默认 xlings 版本 `0.4.58` → **`0.4.60`**(缓存键同步更新)。
+
 ## [0.0.64] — 2026-06-25
 
 ### 修复
diff --git a/mcpp.toml b/mcpp.toml
@@ -1,6 +1,6 @@
 [package]
 name        = "mcpp"
-version     = "0.0.64"
+version     = "0.0.65"
 description = "Modern C++ build & package management tool"
 license     = "Apache-2.0"
 authors     = ["mcpp-community"]
diff --git a/src/build/prepare.cppm b/src/build/prepare.cppm
@@ -2113,13 +2113,44 @@ prepare_build(bool print_fingerprint,
         };
         auto apply = [&](mcpp::modgraph::PackageRoot& pkg,
                          const std::vector<std::string>& requested) {
-            for (auto& f : activate(pkg.manifest, requested)) {
+            auto active = activate(pkg.manifest, requested);
+            for (auto& f : active) {
                 auto def = "-DMCPP_FEATURE_" + sanitize(f);
                 pkg.manifest.buildConfig.cflags.push_back(def);
                 pkg.manifest.buildConfig.cxxflags.push_back(def);
                 pkg.privateBuild.cflags.push_back(def);
                 pkg.privateBuild.cxxflags.push_back(def);
             }
+            // Feature-gated sources (e.g. gtest's gtest_main.cc behind "main"):
+            // drop EVERY feature-listed glob from the default build, then re-add
+            // only the ones whose feature is active. Runs even when no feature is
+            // active, so a gated source is excluded by default.
+            //
+            // ONLY in build mode (!includeDevDeps). `mcpp test` (includeDevDeps)
+            // keeps the full surface so the dev-dependency track's per-test main
+            // detection (run_tests / make_plan) still sees gtest_main.cc and
+            // prunes it per test — the two tracks stay decoupled. Combined with
+            // the descriptor keeping gtest_main.cc in base `sources` too, this
+            // means test mode is unaffected.
+            auto& bc = pkg.manifest.buildConfig;
+            if (!includeDevDeps && !bc.featureSources.empty()) {
+                std::set<std::string> gated;
+                for (auto& [f, globs] : bc.featureSources)
+                    for (auto& g : globs) gated.insert(g);
+                auto drop = [&](std::vector<std::string>& v) {
+                    std::erase_if(v, [&](const std::string& s) { return gated.contains(s); });
+                };
+                drop(bc.sources);
+                drop(pkg.manifest.modules.sources);
+                std::set<std::string> activeSet(active.begin(), active.end());
+                for (auto& [f, globs] : bc.featureSources) {
+                    if (!activeSet.contains(f)) continue;
+                    for (auto& g : globs) {
+                        bc.sources.push_back(g);
+                        pkg.manifest.modules.sources.push_back(g);
+                    }
+                }
+            }
         };
         if (!packages.empty()) {
             std::vector<std::string> rootReq;
@@ -2168,8 +2199,9 @@ prepare_build(bool print_fingerprint,
                     std::println(stderr, "warning: {}", msg);
                 }
             }
-            if (!req.empty() || packages[i].manifest.featuresMap.contains("default"))
-                apply(packages[i], req);
+            // Always apply: even with no requested/default feature, a dep with
+            // feature-gated sources must have those sources dropped by default.
+            apply(packages[i], req);
         }
     }
 
diff --git a/src/cli.cppm b/src/cli.cppm
@@ -255,6 +255,8 @@ int run(int argc, char** argv) {
         .subcommand(cl::App("add")
             .description("Add a dependency to mcpp.toml")
             .arg(cl::Arg("pkg").help("Package spec, e.g. foo@1.0.0").required())
+            .option(cl::Option("dev").help(
+                "Add to [dev-dependencies] (test-only, e.g. gtest)"))
             .action(wrap_rc(mcpp::pm::commands::cmd_add)))
         .subcommand(cl::App("remove")
             .description("Remove a dependency from mcpp.toml")
diff --git a/src/manifest.cppm b/src/manifest.cppm
@@ -105,6 +105,13 @@ struct Toolchain {
 // (new). Defaults are injected by load() after parse if these are empty.
 struct BuildConfig {
     std::vector<std::string>           sources;        // glob patterns
+    // feature name → extra source globs gated by that feature. A glob listed
+    // here is EXCLUDED from the default build and only compiled/linked when the
+    // feature is active for this package (resolved in prepare_build). Lets a
+    // dependency expose an optional component (e.g. gtest's gtest_main.cc behind
+    // the "main" feature) without it being linked by default — see
+    // .agents/docs/2026-06-25-gtest-main-feature-and-add-dev-design.md.
+    std::map<std::string, std::vector<std::string>> featureSources;
     std::vector<std::filesystem::path> includeDirs;    // relative to package root
     std::map<std::filesystem::path, std::string> generatedFiles; // Form B package-owned support files
     bool                                staticStdlib = true;
@@ -1951,6 +1958,55 @@ synthesize_from_xpkg_lua(std::string_view luaContent,
             }
             cur.consume('}');
         }
+        else if (key == "features") {
+            // `{ ["main"] = { sources = { "*/gtest_main.cc" } }, ... }`
+            // Registers the feature (so it's a known feature) and, when it
+            // carries `sources`, records them as feature-gated source globs
+            // (excluded by default; included only when the feature is active —
+            // resolved in prepare_build). A feature with no `sources` is still
+            // registered (empty implied set) so it can be requested/validated.
+            if (!cur.consume('{')) {
+                return std::unexpected(ManifestError{
+                    "expected '{' after `features =`", m.sourcePath, 0, 0});
+            }
+            cur.skip_ws_and_comments();
+            while (!cur.eof() && cur.peek() != '}') {
+                auto fname = cur.read_key();
+                if (fname.empty()) { cur.skip_ws_and_comments(); break; }
+                cur.skip_ws_and_comments();
+                if (!cur.consume('=')) break;
+                cur.skip_ws_and_comments();
+                if (!cur.consume('{')) break;
+                // register the feature (no implied features for now)
+                m.featuresMap.try_emplace(fname, std::vector<std::string>{});
+                cur.skip_ws_and_comments();
+                while (!cur.eof() && cur.peek() != '}') {
+                    auto sub = cur.read_key();
+                    cur.skip_ws_and_comments();
+                    if (!cur.consume('=')) break;
+                    cur.skip_ws_and_comments();
+                    if (sub == "sources") {
+                        if (!cur.consume('{')) break;
+                        cur.skip_ws_and_comments();
+                        while (!cur.eof() && cur.peek() != '}') {
+                            auto s = cur.read_string();
+                            if (!s.empty())
+                                m.buildConfig.featureSources[fname].push_back(std::move(s));
+                            cur.skip_ws_and_comments();
+                        }
+                        cur.consume('}');
+                    } else {
+                        // unknown subfield — skip its value
+                        if (cur.peek() == '{') cur.skip_table();
+                        else (void)cur.read_bareword();
+                    }
+                    cur.skip_ws_and_comments();
+                }
+                cur.consume('}');
+                cur.skip_ws_and_comments();
+            }
+            cur.consume('}');
+        }
         else if (key == "deps") {
             // `{ ["name"] = "version", ["ns.name"] = "version", ... }`
             // The mcpp segment uses the flat / dotted form only — namespaced
diff --git a/src/pm/commands.cppm b/src/pm/commands.cppm
@@ -76,11 +76,15 @@ inline int cmd_add(const mcpplibs::cmdline::ParsedArgs& parsed) {
     //   - Default namespace → `[dependencies] ... name = "version"` (no quotes).
     //   - Other namespace   → `[dependencies.<ns>] ... name = "version"`,
     //                         creating the subtable if absent.
+    // --dev → [dev-dependencies] (test-only deps like gtest; consumed by
+    // `mcpp test`, never linked into `mcpp build` app binaries).
+    const bool dev = parsed.is_flag_set("dev");
+    const std::string table = dev ? "dev-dependencies" : "dependencies";
     const bool isDefaultNs = !explicitNamespace
         || ns == mcpp::manifest::kDefaultNamespace;
     const std::string section = isDefaultNs
-        ? "[dependencies]"
-        : std::format("[dependencies.{}]", ns);
+        ? std::format("[{}]", table)
+        : std::format("[{}.{}]", table, ns);
     const std::string key = explicitNamespace ? shortName : nameSpec;
     auto pos = text.find(section);
     if (pos == std::string::npos) {
@@ -99,7 +103,7 @@ inline int cmd_add(const mcpplibs::cmdline::ParsedArgs& parsed) {
     std::string display = explicitNamespace
         ? (isDefaultNs ? shortName : std::format("{}:{}", ns, shortName))
         : nameSpec;
-    mcpp::ui::status("Adding", std::format("{} v{} to dependencies", display, version));
+    mcpp::ui::status("Adding", std::format("{} v{} to {}", display, version, table));
     std::println("");
     std::println("Run `mcpp build` to fetch and build with the new dependency.");
     return 0;
diff --git a/src/toolchain/fingerprint.cppm b/src/toolchain/fingerprint.cppm
@@ -18,7 +18,7 @@ import mcpp.toolchain.detect;
 
 export namespace mcpp::toolchain {
 
-inline constexpr std::string_view MCPP_VERSION = "0.0.64";
+inline constexpr std::string_view MCPP_VERSION = "0.0.65";
 
 struct FingerprintInputs {
     Toolchain                       toolchain;
diff --git a/tests/e2e/79_gtest_regular_dep_feature_main.sh b/tests/e2e/79_gtest_regular_dep_feature_main.sh
@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# requires:
+# 79_gtest_regular_dep_feature_main.sh — gtest as a REGULAR dependency
+# (`[dependencies]`, via `mcpp add gtest`) must NOT inject gtest_main into a
+# `mcpp build` app that has its own main. Regression for issue #168
+# (`gtest_main.o : error LNK2005: main already defined in main.o`).
+#
+# gtest_main.cc is gated behind the `main` feature in compat.gtest.lua: off by
+# default (framework only) → no main collision; `features = ["main"]` opts in.
+#
+# No `requires:` capability → runs on all three CI platforms (the original bug
+# was Windows/MSVC LNK2005). Depends on the published mcpp-index carrying the
+# gtest `main` feature.
+set -e
+
+TMP=$(mktemp -d)
+trap "rm -rf $TMP" EXIT
+
+cd "$TMP"
+"$MCPP" new app > /dev/null
+cd app
+
+# (1) #168: gtest in [dependencies] + app's own main → build must succeed, and
+#     gtest_main must NOT be linked.
+"$MCPP" add gtest@1.15.2 > /dev/null
+grep -q '^\[dependencies\]' mcpp.toml || { echo "FAIL: add did not write [dependencies]"; cat mcpp.toml; exit 1; }
+"$MCPP" build > /dev/null || { echo "FAIL: #168 — build with regular-dep gtest failed"; exit 1; }
+nj=$(find target -name build.ninja | xargs ls -t 2>/dev/null | head -1)
+if grep -q 'gtest_main' "$nj"; then
+    echo "FAIL: gtest_main linked into app by default (would collide with main)"; exit 1
+fi
+grep -q 'gtest-all' "$nj" || { echo "FAIL: gtest framework (gtest-all) not linked"; exit 1; }
+
+# (2) opt-in: features = ["main"] + a TEST-only file (no own main) → gtest_main
+#     IS linked and provides the entry.
+cat > mcpp.toml <<'EOF'
+[package]
+name = "app"
+version = "0.1.0"
+
+[dependencies]
+gtest = { version = "1.15.2", features = ["main"] }
+EOF
+cat > src/main.cpp <<'EOF'
+#include <gtest/gtest.h>
+TEST(App, ok) { EXPECT_EQ(1 + 1, 2); }
+EOF
+"$MCPP" build > /dev/null || { echo "FAIL: features=[main] build failed"; exit 1; }
+nj=$(find target -name build.ninja | xargs ls -t 2>/dev/null | head -1)
+grep -q 'gtest_main' "$nj" || { echo "FAIL: features=[main] did not link gtest_main"; exit 1; }
+
+# (3) `mcpp add --dev` routes to [dev-dependencies].
+cd "$TMP"
+"$MCPP" new libapp > /dev/null
+cd libapp
+"$MCPP" add --dev gtest@1.15.2 > /dev/null
+grep -q '^\[dev-dependencies\]' mcpp.toml || { echo "FAIL: add --dev did not write [dev-dependencies]"; cat mcpp.toml; exit 1; }
+
+echo "OK"
diff --git a/tests/unit/test_manifest.cpp b/tests/unit/test_manifest.cpp
@@ -395,6 +395,35 @@ package = {
     EXPECT_EQ(m->targets[0].soname, "libtinyshared.so.1");
 }
 
+TEST(SynthesizeFromXpkgLua, FeatureGatedSources) {
+    // gtest-style: gtest_main.cc listed in base `sources` (old-mcpp compat) AND
+    // under the `main` feature → featureSources records it; the feature is
+    // registered in featuresMap. prepare_build later gates it (off by default).
+    constexpr auto src = R"(
+package = {
+    spec = "1",
+    name = "gtestlike",
+    xpm  = { linux = { ["1.0.0"] = { url = "u", sha256 = "h" } } },
+    mcpp = {
+        sources  = { "*/src/all.cc", "*/src/main.cc" },
+        targets  = { ["gtestlike"] = { kind = "lib" } },
+        features = {
+            ["main"] = { sources = { "*/src/main.cc" } },
+        },
+    },
+}
+)";
+    auto m = mcpp::manifest::synthesize_from_xpkg_lua(src, "gtestlike", "1.0.0");
+    ASSERT_TRUE(m.has_value()) << m.error().format();
+    // base sources keep both (old mcpp ignores `features` → no regression)
+    ASSERT_EQ(m->buildConfig.sources.size(), 2u);
+    // the `main` feature is registered + carries its gated source
+    ASSERT_TRUE(m->featuresMap.contains("main"));
+    ASSERT_TRUE(m->buildConfig.featureSources.contains("main"));
+    ASSERT_EQ(m->buildConfig.featureSources.at("main").size(), 1u);
+    EXPECT_EQ(m->buildConfig.featureSources.at("main")[0], "*/src/main.cc");
+}
+
 TEST(SynthesizeFromXpkgLua, RuntimeConfig) {
     constexpr auto src = R"(
 package = {
