Chris@47: // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors Chris@47: // Licensed under the MIT License: Chris@47: // Chris@47: // Permission is hereby granted, free of charge, to any person obtaining a copy Chris@47: // of this software and associated documentation files (the "Software"), to deal Chris@47: // in the Software without restriction, including without limitation the rights Chris@47: // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell Chris@47: // copies of the Software, and to permit persons to whom the Software is Chris@47: // furnished to do so, subject to the following conditions: Chris@47: // Chris@47: // The above copyright notice and this permission notice shall be included in Chris@47: // all copies or substantial portions of the Software. Chris@47: // Chris@47: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR Chris@47: // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, Chris@47: // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE Chris@47: // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER Chris@47: // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, Chris@47: // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN Chris@47: // THE SOFTWARE. Chris@47: Chris@47: #ifndef CAPNP_SCHEMA_PARSER_H_ Chris@47: #define CAPNP_SCHEMA_PARSER_H_ Chris@47: Chris@47: #if defined(__GNUC__) && !defined(CAPNP_HEADER_WARNINGS) Chris@47: #pragma GCC system_header Chris@47: #endif Chris@47: Chris@47: #include "schema-loader.h" Chris@47: #include Chris@47: Chris@47: namespace capnp { Chris@47: Chris@47: class ParsedSchema; Chris@47: class SchemaFile; Chris@47: Chris@47: class SchemaParser { Chris@47: // Parses `.capnp` files to produce `Schema` objects. Chris@47: // Chris@47: // This class is thread-safe, hence all its methods are const. Chris@47: Chris@47: public: Chris@47: SchemaParser(); Chris@47: ~SchemaParser() noexcept(false); Chris@47: Chris@47: ParsedSchema parseDiskFile(kj::StringPtr displayName, kj::StringPtr diskPath, Chris@47: kj::ArrayPtr importPath) const; Chris@47: // Parse a file located on disk. Throws an exception if the file dosen't exist. Chris@47: // Chris@47: // Parameters: Chris@47: // * `displayName`: The name that will appear in the file's schema node. (If the file has Chris@47: // already been parsed, this will be ignored and the display name from the first time it was Chris@47: // parsed will be kept.) Chris@47: // * `diskPath`: The path to the file on disk. Chris@47: // * `importPath`: Directories to search when resolving absolute imports within this file Chris@47: // (imports that start with a `/`). Must remain valid until the SchemaParser is destroyed. Chris@47: // (If the file has already been parsed, this will be ignored and the import path from the Chris@47: // first time it was parsed will be kept.) Chris@47: // Chris@47: // This method is a shortcut, equivalent to: Chris@47: // parser.parseFile(SchemaFile::newDiskFile(displayName, diskPath, importPath))`; Chris@47: // Chris@47: // This method throws an exception if any errors are encountered in the file or in anything the Chris@47: // file depends on. Note that merely importing another file does not count as a dependency on Chris@47: // anything in the imported file -- only the imported types which are actually used are Chris@47: // "dependencies". Chris@47: Chris@47: ParsedSchema parseFile(kj::Own&& file) const; Chris@47: // Advanced interface for parsing a file that may or may not be located in any global namespace. Chris@47: // Most users will prefer `parseDiskFile()`. Chris@47: // Chris@47: // If the file has already been parsed (that is, a SchemaFile that compares equal to this one Chris@47: // was parsed previously), the existing schema will be returned again. Chris@47: // Chris@47: // This method reports errors by calling SchemaFile::reportError() on the file where the error Chris@47: // is located. If that call does not throw an exception, `parseFile()` may in fact return Chris@47: // normally. In this case, the result is a best-effort attempt to compile the schema, but it Chris@47: // may be invalid or corrupt, and using it for anything may cause exceptions to be thrown. Chris@47: Chris@47: template Chris@47: inline void loadCompiledTypeAndDependencies() { Chris@47: // See SchemaLoader::loadCompiledTypeAndDependencies(). Chris@47: getLoader().loadCompiledTypeAndDependencies(); Chris@47: } Chris@47: Chris@47: private: Chris@47: struct Impl; Chris@47: class ModuleImpl; Chris@47: kj::Own impl; Chris@47: mutable bool hadErrors = false; Chris@47: Chris@47: ModuleImpl& getModuleImpl(kj::Own&& file) const; Chris@47: SchemaLoader& getLoader(); Chris@47: Chris@47: friend class ParsedSchema; Chris@47: }; Chris@47: Chris@47: class ParsedSchema: public Schema { Chris@47: // ParsedSchema is an extension of Schema which also has the ability to look up nested nodes Chris@47: // by name. See `SchemaParser`. Chris@47: Chris@47: public: Chris@47: inline ParsedSchema(): parser(nullptr) {} Chris@47: Chris@47: kj::Maybe findNested(kj::StringPtr name) const; Chris@47: // Gets the nested node with the given name, or returns null if there is no such nested Chris@47: // declaration. Chris@47: Chris@47: ParsedSchema getNested(kj::StringPtr name) const; Chris@47: // Gets the nested node with the given name, or throws an exception if there is no such nested Chris@47: // declaration. Chris@47: Chris@47: private: Chris@47: inline ParsedSchema(Schema inner, const SchemaParser& parser): Schema(inner), parser(&parser) {} Chris@47: Chris@47: const SchemaParser* parser; Chris@47: friend class SchemaParser; Chris@47: }; Chris@47: Chris@47: // ======================================================================================= Chris@47: // Advanced API Chris@47: Chris@47: class SchemaFile { Chris@47: // Abstract interface representing a schema file. You can implement this yourself in order to Chris@47: // gain more control over how the compiler resolves imports and reads files. For the Chris@47: // common case of files on disk or other global filesystem-like namespaces, use Chris@47: // `SchemaFile::newDiskFile()`. Chris@47: Chris@47: public: Chris@47: class FileReader { Chris@47: public: Chris@47: virtual bool exists(kj::StringPtr path) const = 0; Chris@47: virtual kj::Array read(kj::StringPtr path) const = 0; Chris@47: }; Chris@47: Chris@47: class DiskFileReader final: public FileReader { Chris@47: // Implementation of FileReader that uses the local disk. Files are read using mmap() if Chris@47: // possible. Chris@47: Chris@47: public: Chris@47: static const DiskFileReader instance; Chris@47: Chris@47: bool exists(kj::StringPtr path) const override; Chris@47: kj::Array read(kj::StringPtr path) const override; Chris@47: }; Chris@47: Chris@47: static kj::Own newDiskFile( Chris@47: kj::StringPtr displayName, kj::StringPtr diskPath, Chris@47: kj::ArrayPtr importPath, Chris@47: const FileReader& fileReader = DiskFileReader::instance); Chris@47: // Construct a SchemaFile representing a file on disk (or located in the filesystem-like Chris@47: // namespace represented by `fileReader`). Chris@47: // Chris@47: // Parameters: Chris@47: // * `displayName`: The name that will appear in the file's schema node. Chris@47: // * `diskPath`: The path to the file on disk. Chris@47: // * `importPath`: Directories to search when resolving absolute imports within this file Chris@47: // (imports that start with a `/`). The array content must remain valid as long as the Chris@47: // SchemaFile exists (which is at least as long as the SchemaParser that parses it exists). Chris@47: // * `fileReader`: Allows you to use a filesystem other than the actual local disk. Although, Chris@47: // if you find yourself using this, it may make more sense for you to implement SchemaFile Chris@47: // yourself. Chris@47: // Chris@47: // The SchemaFile compares equal to any other SchemaFile that has exactly the same disk path, Chris@47: // after canonicalization. Chris@47: // Chris@47: // The SchemaFile will throw an exception if any errors are reported. Chris@47: Chris@47: // ----------------------------------------------------------------- Chris@47: // For more control, you can implement this interface. Chris@47: Chris@47: virtual kj::StringPtr getDisplayName() const = 0; Chris@47: // Get the file's name, as it should appear in the schema. Chris@47: Chris@47: virtual kj::Array readContent() const = 0; Chris@47: // Read the file's entire content and return it as a byte array. Chris@47: Chris@47: virtual kj::Maybe> import(kj::StringPtr path) const = 0; Chris@47: // Resolve an import, relative to this file. Chris@47: // Chris@47: // `path` is exactly what appears between quotes after the `import` keyword in the source code. Chris@47: // It is entirely up to the `SchemaFile` to decide how to map this to another file. Typically, Chris@47: // a leading '/' means that the file is an "absolute" path and is searched for in some list of Chris@47: // schema file repositories. On the other hand, a path that doesn't start with '/' is relative Chris@47: // to the importing file. Chris@47: Chris@47: virtual bool operator==(const SchemaFile& other) const = 0; Chris@47: virtual bool operator!=(const SchemaFile& other) const = 0; Chris@47: virtual size_t hashCode() const = 0; Chris@47: // Compare two SchemaFiles to see if they refer to the same underlying file. This is an Chris@47: // optimization used to avoid the need to re-parse a file to check its ID. Chris@47: Chris@47: struct SourcePos { Chris@47: uint byte; Chris@47: uint line; Chris@47: uint column; Chris@47: }; Chris@47: virtual void reportError(SourcePos start, SourcePos end, kj::StringPtr message) const = 0; Chris@47: // Report that the file contains an error at the given interval. Chris@47: Chris@47: private: Chris@47: class DiskSchemaFile; Chris@47: }; Chris@47: Chris@47: } // namespace capnp Chris@47: Chris@47: #endif // CAPNP_SCHEMA_PARSER_H_