Emit a libman index for build-deps

src/dds.main.cpp

         params.out_root      = out_path.Get();
         params.toolchain     = tc.get_toolchain();
         params.parallel_jobs = n_jobs.Get();
+        params.emit_lmi      = lmi_path.Get();
 
         dds::builder            bd;
         dds::sdist_build_params sdist_params;

src/dds/build/builder.cpp

     return ureqs;
 }
 
+void write_lml(build_env_ref env, const library_plan& lib, path_ref lml_path) {
+    fs::create_directories(lml_path.parent_path());
+    auto out = open(lml_path, std::ios::binary | std::ios::out);
+    out << "Type: Library\n"
+        << "Name: " << lib.name() << '\n'
+        << "Include-Path: " << lib.library_().public_include_dir().generic_string() << '\n';
+    for (auto&& use : lib.uses()) {
+        out << "Uses: " << use.namespace_ << "/" << use.name << '\n';
+    }
+    for (auto&& link : lib.links()) {
+        out << "Links: " << link.namespace_ << "/" << link.name << '\n';
+    }
+    if (auto&& arc = lib.create_archive()) {
+        out << "Path: "
+            << (env.output_root / arc->calc_archive_file_path(env.toolchain)).generic_string()
+            << '\n';
+    }
+}
+
+void write_lmp(build_env_ref env, const package_plan& pkg, path_ref lmp_path) {
+    fs::create_directories(lmp_path.parent_path());
+    auto out = open(lmp_path, std::ios::binary | std::ios::out);
+    out << "Type: Package\n"
+        << "Name: " << pkg.name() << '\n'
+        << "Namespace: " << pkg.namespace_() << '\n';
+    for (const auto& lib : pkg.libraries()) {
+        auto lml_path = lmp_path.parent_path() / pkg.namespace_() / (lib.name() + ".lml");
+        write_lml(env, lib, lml_path);
+        out << "Library: " << lml_path.generic_string() << '\n';
+    }
+}
+
+void write_lmi(build_env_ref env, const build_plan& plan, path_ref base_dir, path_ref lmi_path) {
+    fs::create_directories(lmi_path.parent_path());
+    auto out = open(lmi_path, std::ios::binary | std::ios::out);
+    out << "Type: Index\n";
+    for (const auto& pkg : plan.packages()) {
+        auto lmp_path = base_dir / "_libman" / (pkg.name() + ".lmp");
+        write_lmp(env, pkg, lmp_path);
+        out << "Package: " << pkg.name() << "; " << lmp_path.generic_string() << '\n';
+    }
+}
+
 }  // namespace
 
 void builder::build(const build_params& params) const {
     if (!test_failures.empty()) {
         throw compile_failure("Test failures during the build!");
     }
+
+    if (params.emit_lmi) {
+        write_lmi(env, plan, params.out_root, *params.emit_lmi);
+    }
 }

src/dds/build/params.hpp

 struct build_params {
     fs::path                out_root;
     std::optional<fs::path> existing_lm_index;
+    std::optional<fs::path> emit_lmi;
     dds::toolchain          toolchain;
     bool                    generate_compdb = true;
     int                     parallel_jobs   = 0;

tests/deps/build-deps/test_build_deps.py

     dds.catalog_import(dds.source_root / 'catalog.json')
     dds.build_deps(['-d', 'deps.dds'])
     assert (dds.deps_build_dir / 'neo-sqlite3@0.1.0').is_dir()
+    assert (dds.scratch_dir / 'INDEX.lmi').is_file()
+    assert (dds.deps_build_dir / '_libman/neo-sqlite3.lmp').is_file()
+    assert (dds.deps_build_dir / '_libman/neo/sqlite3.lml').is_file()
 
 
 def test_build_deps_from_cmd(dds: DDS):
     dds.catalog_import(dds.source_root / 'catalog.json')
     dds.build_deps(['neo-sqlite3 =0.1.0'])
     assert (dds.deps_build_dir / 'neo-sqlite3@0.1.0').is_dir()
+    assert (dds.scratch_dir / 'INDEX.lmi').is_file()
+    assert (dds.deps_build_dir / '_libman/neo-sqlite3.lmp').is_file()
+    assert (dds.deps_build_dir / '_libman/neo/sqlite3.lml').is_file()
 
 
 def test_multiple_deps(dds: DDS):
     dds.catalog_import(dds.source_root / 'catalog.json')
     dds.build_deps(['neo-sqlite3 ^0.1.0', 'neo-sqlite3 ~0.2.0'])
     assert (dds.deps_build_dir / 'neo-sqlite3@0.2.2').is_dir()
+    assert (dds.scratch_dir / 'INDEX.lmi').is_file()
+    assert (dds.deps_build_dir / '_libman/neo-sqlite3.lmp').is_file()
+    assert (dds.deps_build_dir / '_libman/neo/sqlite3.lml').is_file()