feat(workspace): self-referential mcpp [workspace] over the index (#57)

The repo becomes both the package index (pkgs/) and a mcpp workspace that
consumes it: a virtual root [workspace] whose members are the per-library
example projects under tests/examples/, each resolving this repo's own pkgs/
via a local [indices] path. Eat our own dog food.

- root mcpp.toml: [workspace].members = cjson/eigen/nlohmann.json/openblas
- tests/run_workspace.sh: thin driver, members are the single source of truth
- tests/examples/openblas: L1-cfg consumer — Windows-only openblas dep+flags
  (cfg(windows)), cblas_dgemm assert on Windows, no-op on linux/macos
- validate.yml: detect.workspace output + smoke-workspace job; MCPP_VERSION
  0.0.73 -> 0.0.77 (carries L1 per-OS deps/flags + [xlings] env)
- design doc: §8 implementation status

Author: Sunrisepeak

.agents/docs/2026-06-29-mcpp-native-workspace-ci-design.md

@@ -192,3 +192,28 @@ windows-runtime-dll(0.0.73)那次"mcpp 补能力 → recipe/CI 变简单"完全
 
 > 关联:本仓 `.github/workflows/validate.yml`(detect 拆分 + 下载缓存,2026-06-29 已落);mcpp 仓
 > `.agents/docs/2026-06-29-windows-runtime-dll-deployment-and-openblas.md`(per-OS 能力如何让 recipe 变简单的先例)。
+
+---
+
+## 8. 实现状态(2026-06-30 落地)
+
+自参照 workspace 的**首个可签入切片**已落地(对应 §6 的 P0 + P1 起步,依赖 mcpp 0.0.77 的 L1
+`[target.'cfg(...)']` per-OS 依赖/flags + windows-runtime-dll 部署):
+
+- **`mcpp.toml`(仓根)**:虚拟 `[workspace]`,`members` 列出 `tests/examples/{cjson,eigen,
+  nlohmann.json,openblas}`——即真实索引的逐库示例本身就是 workspace 成员。仓 = 索引 ⊕ 消费索引的
+  workspace(双视角)。
+- **`tests/run_workspace.sh`**:薄驱动。从仓根 `mcpp.toml` 的 `[workspace].members` 解析成员(单一
+  事实源,无硬编码),逐个 `mcpp build && mcpp run`;每个成员经本地 `[indices]` path 解析**本仓
+  pkgs/** 的真实 recipe。
+- **`tests/examples/openblas/`**:L1-cfg 消费者示范。`[target.'cfg(windows)'.dependencies.compat]
+  openblas` + `[target.'cfg(windows)'.build] cxxflags=["-DHAVE_OPENBLAS=1"]`;Windows 走 `cblas_dgemm`
+  断言 `[19 22; 43 50]`,linux/macos 为 no-op(openblas 不被拉取)。证明 per-OS 依赖按**解析目标
+  三元组**门控。
+- **`validate.yml`**:`detect` 增 `workspace` 输出(push/schedule 全跑;PR 命中仓根 `mcpp.toml`、
+  `tests/run_workspace.sh`、或任一 `tests/examples/*` 成员时触发);新增 `smoke-workspace`(ubuntu)
+  跑驱动。`MCPP_VERSION` 升至 0.0.77。
+
+**尚未收敛**(留待 §6 P2/P3):per-OS 成员差异仍可由 cfg 表承担而非驱动;环境隔离/缓存/产物断言仍在
+各 smoke 脚本;`--workspace` 单命令(G1)仍是 mcpp 侧待加能力——当前驱动按成员循环。旧 smoke 脚本
+**保留**,与 workspace 并行覆盖,等价验证充分后再逐个迁移/删除。

.github/workflows/validate.yml

@@ -11,9 +11,9 @@ on:
   workflow_dispatch:
 
 env:
-  # Bumped to 0.0.73: carries Windows runtime-DLL deployment, required by the
+  # Bumped to 0.0.77: carries L1 platform-conditional deps/flags + [xlings] env,
   # compat.openblas Windows recipe (bin/libopenblas.dll staged beside the .exe).
-  MCPP_VERSION: "0.0.73"
+  MCPP_VERSION: "0.0.77"
 
 jobs:
   lint:
@@ -105,6 +105,7 @@ jobs:
       full: ${{ steps.f.outputs.full }}
       full_linux: ${{ steps.f.outputs.full_linux }}
       full_portable: ${{ steps.f.outputs.full_portable }}
+      workspace: ${{ steps.f.outputs.workspace }}
     steps:
       - uses: actions/checkout@v4
         with:
@@ -123,11 +124,12 @@ jobs:
           # coverage is ever silently dropped).
           full_linux=false
           full_portable=false
+          workspace=false
           examples='[]'
           event="${{ github.event_name }}"
           if [ "$event" != "pull_request" ]; then
             # push to main / nightly schedule / manual dispatch → full regression
-            full_linux=true; full_portable=true
+            full_linux=true; full_portable=true; workspace=true
           else
             git fetch -q origin "${{ github.base_ref }}"
             changed=$(git diff --name-only "origin/${{ github.base_ref }}...HEAD")
@@ -138,16 +140,22 @@ jobs:
               case "$file" in
                 # Common harness / the workflow itself → both platforms.
                 tests/run_example.sh|tests/check_mirror_urls.lua|tests/list_cn_urls.lua|.github/workflows/validate.yml)
-                  full_linux=true; full_portable=true ;;
+                  full_linux=true; full_portable=true; workspace=true ;;
+                # The self-referential workspace: its declaration (root mcpp.toml)
+                # and its driver. A member change under tests/examples/* also feeds
+                # the workspace job (handled below, with the examples fast path).
+                mcpp.toml|tests/run_workspace.sh)
+                  workspace=true ;;
                 # Portable suite script runs only in smoke-portable (win+mac).
                 tests/smoke_compat_portable.sh)
                   full_portable=true ;;
                 # Linux-only smoke scripts run only in smoke-full-linux.
                 tests/smoke_compat_core.sh|tests/smoke_compat_imgui.sh|tests/smoke_compat_archive.sh|tests/smoke_compat_imgui_window.sh|tests/smoke_imgui_module.sh)
                   full_linux=true ;;
-                # Example projects are handled by the smoke-examples fast path.
+                # Example projects are handled by the smoke-examples fast path;
+                # they are also workspace members, so re-run the workspace driver.
                 tests/examples/*)
-                  : ;;
+                  workspace=true ;;
                 # Any other tests/ change (new helper / new smoke script) → both (safe).
                 tests/*)
                   full_linux=true; full_portable=true ;;
@@ -171,8 +179,9 @@ jobs:
           echo "full=$full" >> "$GITHUB_OUTPUT"
           echo "full_linux=$full_linux" >> "$GITHUB_OUTPUT"
           echo "full_portable=$full_portable" >> "$GITHUB_OUTPUT"
+          echo "workspace=$workspace" >> "$GITHUB_OUTPUT"
           echo "examples=$examples" >> "$GITHUB_OUTPUT"
-          echo "=> full_linux=$full_linux full_portable=$full_portable examples=$examples"
+          echo "=> full_linux=$full_linux full_portable=$full_portable workspace=$workspace examples=$examples"
 
   # ── Fast path: per-changed-package example projects (Linux) ───────────
   smoke-examples:
@@ -210,6 +219,44 @@ jobs:
           "$MCPP" --version
           timeout 1800 bash tests/run_example.sh "${{ matrix.pkg }}"
 
+  # ── Self-referential workspace: mcpp-index AS a mcpp [workspace] ──────
+  # Dogfoods mcpp's own native [workspace]: the root mcpp.toml declares every
+  # per-library example as a workspace member, and the driver builds+runs each
+  # through the real pkgs/ index (local [indices] path). This is the dual
+  # perspective — the repo is both the package index and a consumer of it. The
+  # openblas member additionally exercises L1 platform-conditional deps/flags
+  # (no-op here on linux; the Windows cblas path is covered by smoke-portable).
+  smoke-workspace:
+    needs: detect
+    if: needs.detect.outputs.workspace == 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Restore mcpp registry cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.mcpp/registry
+          key: mcpp-registry-${{ runner.os }}-${{ env.MCPP_VERSION }}-${{ hashFiles('pkgs/**/*.lua', 'tests/**', '.github/workflows/validate.yml') }}
+          restore-keys: |
+            mcpp-registry-${{ runner.os }}-${{ env.MCPP_VERSION }}-
+      - name: Download mcpp
+        run: |
+          curl -L -fsS -o mcpp.tar.gz \
+            "https://github.com/mcpp-community/mcpp/releases/download/v${MCPP_VERSION}/mcpp-${MCPP_VERSION}-linux-x86_64.tar.gz"
+          tar -xzf mcpp.tar.gz
+          root="$PWD/mcpp-${MCPP_VERSION}-linux-x86_64"
+          mkdir -p "$HOME/.mcpp/registry"
+          cp -a "$root/registry/." "$HOME/.mcpp/registry/"
+          echo "MCPP=$root/bin/mcpp" >> "$GITHUB_ENV"
+          echo "MCPP_VENDORED_XLINGS=$root/registry/bin/xlings" >> "$GITHUB_ENV"
+          echo "$root/bin" >> "$GITHUB_PATH"
+      - name: Build + run every workspace member
+        env:
+          MCPP_INDEX_MIRROR: GLOBAL
+        run: |
+          "$MCPP" --version
+          timeout 1800 bash tests/run_workspace.sh
+
   # ── Full regression (legacy whole-suite smoke) ────────────────────────
   smoke-full-linux:
     needs: detect
@@ -279,14 +326,14 @@ jobs:
         include:
           - platform: macos
             os: macos-15
-            archive: mcpp-0.0.73-macosx-arm64.tar.gz
-            root: mcpp-0.0.73-macosx-arm64
+            archive: mcpp-0.0.77-macosx-arm64.tar.gz
+            root: mcpp-0.0.77-macosx-arm64
             mcpp: bin/mcpp
             xlings: registry/bin/xlings
           - platform: windows
             os: windows-latest
-            archive: mcpp-0.0.73-windows-x86_64.zip
-            root: mcpp-0.0.73-windows-x86_64
+            archive: mcpp-0.0.77-windows-x86_64.zip
+            root: mcpp-0.0.77-windows-x86_64
             mcpp: bin/mcpp.exe
             xlings: registry/bin/xlings.exe
     steps:

mcpp.toml

@@ -0,0 +1,12 @@
+# mcpp-index is simultaneously the package index (pkgs/) AND a mcpp workspace that
+# tests it: a virtual workspace whose members are the per-library example/test
+# projects under tests/examples/, each consuming this repo's own pkgs/ via a local
+# [indices] path. "Eat our own dog food." See
+# .agents/docs/2026-06-29-mcpp-native-workspace-ci-design.md.
+[workspace]
+members = [
+    "tests/examples/cjson",
+    "tests/examples/eigen",
+    "tests/examples/nlohmann.json",
+    "tests/examples/openblas",
+]

tests/examples/openblas/mcpp.toml

@@ -0,0 +1,22 @@
+# L1-cfg consumer: openblas is a Windows-only runtime dependency (import lib +
+# DLL); on linux/macos this member is a trivial no-op binary. Demonstrates mcpp's
+# platform-conditional [target.'cfg(...)'] dependencies + flags (mcpp >= 0.0.75),
+# with the windows-runtime-DLL deployment (mcpp >= 0.0.73). Self-referential:
+# the openblas recipe is resolved from THIS repo's pkgs/ via the local index.
+[package]
+name    = "openblas-example"
+version = "0.1.0"
+
+[indices]
+compat = { path = "../../.." }
+
+# Pull OpenBLAS only when building for Windows; define HAVE_OPENBLAS so the source
+# compiles the cblas path there and a no-op everywhere else.
+[target.'cfg(windows)'.dependencies.compat]
+openblas = "0.3.33"
+[target.'cfg(windows)'.build]
+cxxflags = ["-DHAVE_OPENBLAS=1"]
+
+[targets.openblas-example]
+kind = "bin"
+main = "src/main.cpp"

tests/examples/openblas/src/main.cpp

@@ -0,0 +1,16 @@
+// Portable: on Windows the cfg-gated openblas dep + HAVE_OPENBLAS are active and
+// this calls cblas_dgemm (asserting [19 22; 43 50]); elsewhere it is a no-op.
+#ifdef HAVE_OPENBLAS
+#include <cblas.h>
+int main() {
+    const double A[4] = {1, 2, 3, 4};
+    const double B[4] = {5, 6, 7, 8};
+    double C[4] = {0, 0, 0, 0};
+    cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, 2, 2, 2, 1.0, A, 2, B, 2, 0.0, C, 2);
+    const double expected[4] = {19, 22, 43, 50};
+    for (int i = 0; i < 4; ++i) if (C[i] != expected[i]) return 10 + i;
+    return 0;
+}
+#else
+int main() { return 0; }  // openblas is Windows-only; no-op elsewhere
+#endif

tests/run_workspace.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# run_workspace.sh — drive the self-referential mcpp workspace: build + run every
+# member declared in the root mcpp.toml [workspace].members. Each member is a
+# per-library example/test project that consumes THIS repo's pkgs/ via a local
+# [indices] path, so this exercises the real package descriptors through the real
+# mcpp pipeline — and dogfoods mcpp's own [workspace]. The member list is the
+# single source of truth (no hardcoded duplication).
+# Usage: MCPP=/path/to/mcpp tests/run_workspace.sh
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+MCPP_BIN="${MCPP:-$(command -v mcpp || true)}"
+[ -n "$MCPP_BIN" ] && [ -x "$MCPP_BIN" ] || { echo "FATAL: set MCPP=/path/to/mcpp" >&2; exit 1; }
+
+# Read [workspace].members from the root mcpp.toml (one "path" per line).
+members=$(awk '
+  /^\[workspace\]/ {inws=1; next}
+  /^\[/ && !/^\[workspace\]/ {inws=0}
+  inws && /"/ { gsub(/[",[:space:]]/,""); if ($0!="members=[" && $0!="") print $0 }
+' "$ROOT/mcpp.toml" | sed 's/members=\[//;s/\]//' | grep -v '^$')
+
+[ -n "$members" ] || { echo "FATAL: no [workspace].members in $ROOT/mcpp.toml" >&2; exit 1; }
+echo "workspace members:"; echo "$members" | sed 's/^/  /'
+
+for m in $members; do
+    dir="$ROOT/$m"
+    [ -d "$dir" ] || { echo "FATAL: member dir missing: $m" >&2; exit 1; }
+    echo "==> [$m] mcpp build + run"
+    ( cd "$dir"
+      rm -rf target .mcpp           # hermetic: exercise the index descriptor, not a stale cache
+      "$MCPP_BIN" build
+      "$MCPP_BIN" run )
+    echo "OK: $m"
+done
+echo "ALL WORKSPACE MEMBERS OK"