mpgen: Avoid deprecated SchemaParser::parseDiskFile call

This avoids deprecation warnings, and is potentially a little safer since it
sandboxes the parsing and makes it an error to import paths outside the source
directory.

This change does have some downsides, though. It complicates include logic, and
also drops compatibility with capnproto versions before 0.7.0 that don't have
the new SchemaParser::parseFromDirectory method which was added in
capnproto/capnproto@c1fe2b0
It also adds a hard dependency on the kj/filesystem.h library which was
previously optional.

Fixes #39

Author: ryanofsky

cmake/capnp_compat.cmake

@@ -2,11 +2,8 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-# CMake target definitions for backwards compatibility with Ubuntu bionic
-# capnproto 0.6.1 package (https://packages.ubuntu.com/bionic/libcapnp-dev)
-
-include(CheckIncludeFileCXX)
-include(CMakePushCheckState)
+# Define capnp_PREFIX if not defined to avoid issue on macos
+# https://github.com/chaincodelabs/libmultiprocess/issues/26
 
 if (NOT DEFINED capnp_PREFIX AND DEFINED CAPNP_INCLUDE_DIRS)
   get_filename_component(capnp_PREFIX "${CAPNP_INCLUDE_DIRS}" DIRECTORY)
@@ -16,6 +13,10 @@ if (NOT DEFINED CAPNPC_OUTPUT_DIR)
   set(CAPNPC_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}")
 endif()
 
+# CMake target definitions for backwards compatibility with Ubuntu bionic
+# capnproto 0.6.1 package (https://packages.ubuntu.com/bionic/libcapnp-dev)
+# https://github.com/chaincodelabs/libmultiprocess/issues/27
+
 if (NOT DEFINED CAPNP_LIB_CAPNPC AND DEFINED CAPNP_LIB_CAPNP-RPC)
   string(REPLACE "-rpc" "c" CAPNP_LIB_CAPNPC "${CAPNP_LIB_CAPNP-RPC}")
 endif()
@@ -53,8 +54,3 @@ if (NOT TARGET CapnProto::kj-async AND DEFINED CAPNP_LIB_KJ-ASYNC)
   add_library(CapnProto::kj-async SHARED IMPORTED)
   set_target_properties(CapnProto::kj-async PROPERTIES IMPORTED_LOCATION "${CAPNP_LIB_KJ-ASYNC}")
 endif()
-
-cmake_push_check_state()
-set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${CAPNP_INCLUDE_DIRS})
-check_include_file_cxx("kj/filesystem.h" HAVE_KJ_FILESYSTEM)
-cmake_pop_check_state()

src/mp/gen.cpp

@@ -126,7 +126,9 @@ bool BoxedType(const ::capnp::Type& type)
 void Generate(kj::StringPtr src_prefix,
     kj::StringPtr include_prefix,
     kj::StringPtr src_file,
-    kj::ArrayPtr<const kj::StringPtr> import_paths)
+    const std::vector<kj::StringPtr>& import_paths,
+    const kj::ReadableDirectory& src_dir,
+    const std::vector<kj::Own<const kj::ReadableDirectory>>& import_dirs)
 {
     std::string output_path;
     if (src_prefix == ".") {
@@ -176,7 +178,11 @@ void Generate(kj::StringPtr src_prefix,
     }
 
     capnp::SchemaParser parser;
-    auto file_schema = parser.parseDiskFile(src_file, src_file, import_paths);
+    auto directory_pointers = kj::heapArray<const kj::ReadableDirectory*>(import_dirs.size());
+    for (size_t i = 0; i < import_dirs.size(); ++i) {
+        directory_pointers[i] = import_dirs[i].get();
+    }
+    auto file_schema = parser.parseFromDirectory(src_dir, kj::Path::parse(output_path), directory_pointers);
 
     std::ofstream cpp_server(output_path + ".proxy-server.c++");
     cpp_server << "// Generated by " PROXY_BIN " from " << src_file << "\n\n";
@@ -611,20 +617,30 @@ int main(int argc, char** argv)
         exit(1);
     }
     std::vector<kj::StringPtr> import_paths;
-#ifdef HAVE_KJ_FILESYSTEM
+    std::vector<kj::Own<const kj::ReadableDirectory>> import_dirs;
     auto fs = kj::newDiskFilesystem();
     auto cwd = fs->getCurrentPath();
-#endif
+    kj::Own<const kj::ReadableDirectory> src_dir;
+    KJ_IF_MAYBE(dir, fs->getRoot().tryOpenSubdir(cwd.evalNative(argv[1]))) {
+        src_dir = kj::mv(*dir);
+    } else {
+        throw std::runtime_error(std::string("Failed to open src_prefix prefix directory: ") + argv[1]);
+    }
     for (size_t i = 4; i < argc; ++i) {
-        import_paths.emplace_back(argv[i]);
+        KJ_IF_MAYBE(dir, fs->getRoot().tryOpenSubdir(cwd.evalNative(argv[i]))) {
+            import_paths.emplace_back(argv[i]);
+            import_dirs.emplace_back(kj::mv(*dir));
+        } else {
+            throw std::runtime_error(std::string("Failed to open import directory: ") + argv[i]);
+        }
     }
     for (const char* path : {CMAKE_INSTALL_PREFIX "/include", capnp_PREFIX "/include"}) {
-#ifdef HAVE_KJ_FILESYSTEM
-        KJ_IF_MAYBE(dir, fs->getRoot().tryOpenSubdir(cwd.evalNative(path))) { import_paths.emplace_back(path); }
-#else
-        import_paths.emplace_back(path);
-#endif
+        KJ_IF_MAYBE(dir, fs->getRoot().tryOpenSubdir(cwd.evalNative(path))) {
+            import_paths.emplace_back(path);
+            import_dirs.emplace_back(kj::mv(*dir));
+        }
+        // No exception thrown if _PREFIX directories do not exist
     }
-    Generate(argv[1], argv[2], argv[3], {import_paths.data(), import_paths.size()});
+    Generate(argv[1], argv[2], argv[3], import_paths, *src_dir, import_dirs);
     return 0;
 }