// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Author: kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
//
// This file is the public interface to the .proto file parser.
#ifndef GOOGLE_PROTOBUF_COMPILER_IMPORTER_H__
#define GOOGLE_PROTOBUF_COMPILER_IMPORTER_H__
#include <string>
#include <vector>
#include <set>
#include <utility>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/descriptor_database.h>
#include <google/protobuf/compiler/parser.h>
namespace google {
namespace protobuf {
namespace io { class ZeroCopyInputStream; }
namespace compiler {
// Defined in this file.
class Importer;
class MultiFileErrorCollector;
class SourceTree;
class DiskSourceTree;
// TODO(kenton): Move all SourceTree stuff to a separate file?
// An implementation of DescriptorDatabase which loads files from a SourceTree
// and parses them.
//
// Note: This class is not thread-safe since it maintains a table of source
// code locations for error reporting. However, when a DescriptorPool wraps
// a DescriptorDatabase, it uses mutex locking to make sure only one method
// of the database is called at a time, even if the DescriptorPool is used
// from multiple threads. Therefore, there is only a problem if you create
// multiple DescriptorPools wrapping the same SourceTreeDescriptorDatabase
// and use them from multiple threads.
//
// Note: This class does not implement FindFileContainingSymbol() or
// FindFileContainingExtension(); these will always return false.
class LIBPROTOBUF_EXPORT SourceTreeDescriptorDatabase : public DescriptorDatabase {
public:
SourceTreeDescriptorDatabase(SourceTree* source_tree);
~SourceTreeDescriptorDatabase();
// Instructs the SourceTreeDescriptorDatabase to report any parse errors
// to the given MultiFileErrorCollector. This should be called before
// parsing. error_collector must remain valid until either this method
// is called again or the SourceTreeDescriptorDatabase is destroyed.
void RecordErrorsTo(MultiFileErrorCollector* error_collector) {
error_collector_ = error_collector;
}
// Gets a DescriptorPool::ErrorCollector which records errors to the
// MultiFileErrorCollector specified with RecordErrorsTo(). This collector
// has the ability to determine exact line and column numbers of errors
// from the information given to it by the DescriptorPool.
DescriptorPool::ErrorCollector* GetValidationErrorCollector() {
using_validation_error_collector_ = true;
return &validation_error_collector_;
}
// implements DescriptorDatabase -----------------------------------
bool FindFileByName(const string& filename, FileDescriptorProto* output);
bool FindFileContainingSymbol(const string& symbol_name,
FileDescriptorProto* output);
bool FindFileContainingExtension(const string& containing_type,
int field_number,
FileDescriptorProto* output);
private:
class SingleFileErrorCollector;
SourceTree* source_tree_;
MultiFileErrorCollector* error_collector_;
class LIBPROTOBUF_EXPORT ValidationErrorCollector : public DescriptorPool::ErrorCollector {
public:
ValidationErrorCollector(SourceTreeDescriptorDatabase* owner);
~ValidationErrorCollector();
// implements ErrorCollector ---------------------------------------
void AddError(const string& filename,
const string& element_name,
const Message* descriptor,
ErrorLocation location,
const string& message);
private:
SourceTreeDescriptorDatabase* owner_;
};
friend class ValidationErrorCollector;
bool using_validation_error_collector_;
SourceLocationTable source_locations_;
ValidationErrorCollector validation_error_collector_;
};
// Simple interface for parsing .proto files. This wraps the process
// of opening the file, parsing it with a Parser, recursively parsing all its
// imports, and then cross-linking the results to produce a FileDescriptor.
//
// This is really just a thin wrapper around SourceTreeDescriptorDatabase.
// You may find that SourceTreeDescriptorDatabase is more flexible.
//
// TODO(kenton): I feel like this class is not well-named.
class LIBPROTOBUF_EXPORT Importer {
public:
Importer(SourceTree* source_tree,
MultiFileErrorCollector* error_collector);
~Importer();
// Import the given file and build a FileDescriptor representing it. If
// the file is already in the DescriptorPool, the existing FileDescriptor
// will be returned. The FileDescriptor is property of the DescriptorPool,
// and will remain valid until it is destroyed. If any errors occur, they
// will be reported using the error collector and Import() will return NULL.
//
// A particular Importer object will only report errors for a particular
// file once. All future attempts to import the same file will return NULL
// without reporting any errors. The idea is that you might want to import
// a lot of files without seeing the same errors over and over again. If
// you want to see errors for the same files repeatedly, you can use a
// separate Importer object to import each one (but use the same
// DescriptorPool so that they can be cross-linked).
const FileDescriptor* Import(const string& filename);
// The DescriptorPool in which all imported FileDescriptors and their
// contents are stored.
inline const DescriptorPool* pool() const {
return &pool_;
}
private:
SourceTreeDescriptorDatabase database_;
DescriptorPool pool_;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Importer);
};
// If the importer encounters problems while trying to import the proto files,
// it reports them to a MultiFileErrorCollector.
class LIBPROTOBUF_EXPORT MultiFileErrorCollector {
public:
inline MultiFileErrorCollector() {}
virtual ~MultiFileErrorCollector();
// Line and column numbers are zero-based. A line number of -1 indicates
// an error with the entire file (e.g. "not found").
virtual void AddError(const string& filename, int line, int column,
const string& message) = 0;
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MultiFileErrorCollector);
};
// Abstract interface which represents a directory tree containing proto files.
// Used by the default implementation of Importer to resolve import statements
// Most users will probably want to use the DiskSourceTree implementation,
// below.
class LIBPROTOBUF_EXPORT SourceTree {
public:
inline SourceTree() {}
virtual ~SourceTree();
// Open the given file and return a stream that reads it, or NULL if not
// found. The caller takes ownership of the returned object. The filename
// must be a path relative to the root of the source tree and must not
// contain "." or ".." components.
virtual io::ZeroCopyInputStream* Open(const string& filename) = 0;
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(SourceTree);
};
// An implementation of SourceTree which loads files from locations on disk.
// Multiple mappings can be set up to map locations in the DiskSourceTree to
// locations in the physical filesystem.
class LIBPROTOBUF_EXPORT DiskSourceTree : public SourceTree {
public:
DiskSourceTree();
~DiskSourceTree();
// Map a path on disk to a location in the SourceTree. The path may be
// either a file or a directory. If it is a directory, the entire tree
// under it will be mapped to the given virtual location. To map a directory
// to the root of the source tree, pass an empty string for virtual_path.
//
// If multiple mapped paths apply when opening a file, they will be searched
// in order. For example, if you do:
// MapPath("bar", "foo/bar");
// MapPath("", "baz");
// and then you do:
// Open("bar/qux");
// the DiskSourceTree will first try to open foo/bar/qux, then baz/bar/qux,
// returning the first one that opens successfuly.
//
// disk_path may be an absolute path or relative to the current directory,
// just like a path you'd pass to open().
void MapPath(const string& virtual_path, const string& disk_path);
// Return type for DiskFileToVirtualFile().
enum DiskFileToVirtualFileResult {
SUCCESS,
SHADOWED,
CANNOT_OPEN,
NO_MAPPING
};
// Given a path to a file on disk, find a virtual path mapping to that
// file. The first mapping created with MapPath() whose disk_path contains
// the filename is used. However, that virtual path may not actually be
// usable to open the given file. Possible return values are:
// * SUCCESS: The mapping was found. *virtual_file is filled in so that
// calling Open(*virtual_file) will open the file named by disk_file.
// * SHADOWED: A mapping was found, but using Open() to open this virtual
// path will end up returning some different file. This is because some
// other mapping with a higher precedence also matches this virtual path
// and maps it to a different file that exists on disk. *virtual_file
// is filled in as it would be in the SUCCESS case. *shadowing_disk_file
// is filled in with the disk path of the file which would be opened if
// you were to call Open(*virtual_file).
// * CANNOT_OPEN: The mapping was found and was not shadowed, but the
// file specified cannot be opened. When this value is returned,
// errno will indicate the reason the file cannot be opened. *virtual_file
// will be set to the virtual path as in the SUCCESS case, even though
// it is not useful.
// * NO_MAPPING: Indicates that no mapping was found which contains this
// file.
DiskFileToVirtualFileResult
DiskFileToVirtualFile(const string& disk_file,
string* virtual_file,
string* shadowing_disk_file);
// Given a virtual path, find the path to the file on disk.
// Return true and update disk_file with the on-disk path if the file exists.
// Return false and leave disk_file untouched if the file doesn't exist.
bool VirtualFileToDiskFile(const string& virtual_file, string* disk_file);
// implements SourceTree -------------------------------------------
io::ZeroCopyInputStream* Open(const string& filename);
private:
struct Mapping {
string virtual_path;
string disk_path;
inline Mapping(const string& virtual_path_param,
const string& disk_path_param)
: virtual_path(virtual_path_param), disk_path(disk_path_param) {}
};
vector<Mapping> mappings_;
// Like Open(), but returns the on-disk path in disk_file if disk_file is
// non-NULL and the file could be successfully opened.
io::ZeroCopyInputStream* OpenVirtualFile(const string& virtual_file,
string* disk_file);
// Like Open() but given the actual on-disk path.
io::ZeroCopyInputStream* OpenDiskFile(const string& filename);
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DiskSourceTree);
};
} // namespace compiler
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_COMPILER_IMPORTER_H__