// 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.
//
// Implements parsing of .proto files to FileDescriptorProtos.
#ifndef GOOGLE_PROTOBUF_COMPILER_PARSER_H__
#define GOOGLE_PROTOBUF_COMPILER_PARSER_H__
#include <map>
#include <string>
#include <utility>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/descriptor.h>
#include <google/protobuf/descriptor.pb.h>
#include <google/protobuf/repeated_field.h>
#include <google/protobuf/io/tokenizer.h>
namespace google {
namespace protobuf { class Message; }
namespace protobuf {
namespace compiler {
// Defined in this file.
class Parser;
class SourceLocationTable;
// Implements parsing of protocol definitions (such as .proto files).
//
// Note that most users will be more interested in the Importer class.
// Parser is a lower-level class which simply converts a single .proto file
// to a FileDescriptorProto. It does not resolve import directives or perform
// many other kinds of validation needed to construct a complete
// FileDescriptor.
class LIBPROTOBUF_EXPORT Parser {
public:
Parser();
~Parser();
// Parse the entire input and construct a FileDescriptorProto representing
// it. Returns true if no errors occurred, false otherwise.
bool Parse(io::Tokenizer* input, FileDescriptorProto* file);
// Optional fetaures:
// DEPRECATED: New code should use the SourceCodeInfo embedded in the
// FileDescriptorProto.
//
// Requests that locations of certain definitions be recorded to the given
// SourceLocationTable while parsing. This can be used to look up exact line
// and column numbers for errors reported by DescriptorPool during validation.
// Set to NULL (the default) to discard source location information.
void RecordSourceLocationsTo(SourceLocationTable* location_table) {
source_location_table_ = location_table;
}
// Requests that errors be recorded to the given ErrorCollector while
// parsing. Set to NULL (the default) to discard error messages.
void RecordErrorsTo(io::ErrorCollector* error_collector) {
error_collector_ = error_collector;
}
// Returns the identifier used in the "syntax = " declaration, if one was
// seen during the last call to Parse(), or the empty string otherwise.
const string& GetSyntaxIdentifier() { return syntax_identifier_; }
// If set true, input files will be required to begin with a syntax
// identifier. Otherwise, files may omit this. If a syntax identifier
// is provided, it must be 'syntax = "proto2";' and must appear at the
// top of this file regardless of whether or not it was required.
void SetRequireSyntaxIdentifier(bool value) {
require_syntax_identifier_ = value;
}
// Call SetStopAfterSyntaxIdentifier(true) to tell the parser to stop
// parsing as soon as it has seen the syntax identifier, or lack thereof.
// This is useful for quickly identifying the syntax of the file without
// parsing the whole thing. If this is enabled, no error will be recorded
// if the syntax identifier is something other than "proto2" (since
// presumably the caller intends to deal with that), but other kinds of
// errors (e.g. parse errors) will still be reported. When this is enabled,
// you may pass a NULL FileDescriptorProto to Parse().
void SetStopAfterSyntaxIdentifier(bool value) {
stop_after_syntax_identifier_ = value;
}
private:
class LocationRecorder;
// =================================================================
// Error recovery helpers
// Consume the rest of the current statement. This consumes tokens
// until it sees one of:
// ';' Consumes the token and returns.
// '{' Consumes the brace then calls SkipRestOfBlock().
// '}' Returns without consuming.
// EOF Returns (can't consume).
// The Parser often calls SkipStatement() after encountering a syntax
// error. This allows it to go on parsing the following lines, allowing
// it to report more than just one error in the file.
void SkipStatement();
// Consume the rest of the current block, including nested blocks,
// ending after the closing '}' is encountered and consumed, or at EOF.
void SkipRestOfBlock();
// -----------------------------------------------------------------
// Single-token consuming helpers
//
// These make parsing code more readable.
// True if the current token is TYPE_END.
inline bool AtEnd();
// True if the next token matches the given text.
inline bool LookingAt(const char* text);
// True if the next token is of the given type.
inline bool LookingAtType(io::Tokenizer::TokenType token_type);
// If the next token exactly matches the text given, consume it and return
// true. Otherwise, return false without logging an error.
bool TryConsume(const char* text);
// These attempt to read some kind of token from the input. If successful,
// they return true. Otherwise they return false and add the given error
// to the error list.
// Consume a token with the exact text given.
bool Consume(const char* text, const char* error);
// Same as above, but automatically generates the error "Expected \"text\".",
// where "text" is the expected token text.
bool Consume(const char* text);
// Consume a token of type IDENTIFIER and store its text in "output".
bool ConsumeIdentifier(string* output, const char* error);
// Consume an integer and store its value in "output".
bool ConsumeInteger(int* output, const char* error);
// Consume a signed integer and store its value in "output".
bool ConsumeSignedInteger(int* output, const char* error);
// Consume a 64-bit integer and store its value in "output". If the value
// is greater than max_value, an error will be reported.
bool ConsumeInteger64(uint64 max_value, uint64* output, const char* error);
// Consume a number and store its value in "output". This will accept
// tokens of either INTEGER or FLOAT type.
bool ConsumeNumber(double* output, const char* error);
// Consume a string literal and store its (unescaped) value in "output".
bool ConsumeString(string* output, const char* error);
// Consume a token representing the end of the statement. Comments between
// this token and the next will be harvested for documentation. The given
// LocationRecorder should refer to the declaration that was just parsed;
// it will be populated with these comments.
//
// TODO(kenton): The LocationRecorder is const because historically locations
// have been passed around by const reference, for no particularly good
// reason. We should probably go through and change them all to mutable
// pointer to make this more intuitive.
bool TryConsumeEndOfDeclaration(const char* text,
const LocationRecorder* location);
bool ConsumeEndOfDeclaration(const char* text,
const LocationRecorder* location);
// -----------------------------------------------------------------
// Error logging helpers
// Invokes error_collector_->AddError(), if error_collector_ is not NULL.
void AddError(int line, int column, const string& error);
// Invokes error_collector_->AddError() with the line and column number
// of the current token.
void AddError(const string& error);
// Records a location in the SourceCodeInfo.location table (see
// descriptor.proto). We use RAII to ensure that the start and end locations
// are recorded -- the constructor records the start location and the
// destructor records the end location. Since the parser is
// recursive-descent, this works out beautifully.
class LIBPROTOBUF_EXPORT LocationRecorder {
public:
// Construct the file's "root" location.
LocationRecorder(Parser* parser);
// Construct a location that represents a declaration nested within the
// given parent. E.g. a field's location is nested within the location
// for a message type. The parent's path will be copied, so you should
// call AddPath() only to add the path components leading from the parent
// to the child (as opposed to leading from the root to the child).
LocationRecorder(const LocationRecorder& parent);
// Convenience constructors that call AddPath() one or two times.
LocationRecorder(const LocationRecorder& parent, int path1);
LocationRecorder(const LocationRecorder& parent, int path1, int path2);
~LocationRecorder();
// Add a path component. See SourceCodeInfo.Location.path in
// descriptor.proto.
void AddPath(int path_component);
// By default the location is considered to start at the current token at
// the time the LocationRecorder is created. StartAt() sets the start
// location to the given token instead.
void StartAt(const io::Tokenizer::Token& token);
// By default the location is considered to end at the previous token at
// the time the LocationRecorder is destroyed. EndAt() sets the end
// location to the given token instead.
void EndAt(const io::Tokenizer::Token& token);
// Records the start point of this location to the SourceLocationTable that
// was passed to RecordSourceLocationsTo(), if any. SourceLocationTable
// is an older way of keeping track of source locations which is still
// used in some places.
void RecordLegacyLocation(const Message* descriptor,
DescriptorPool::ErrorCollector::ErrorLocation location);
// Attaches leading and trailing comments to the location. The two strings
// will be swapped into place, so after this is called *leading and
// *trailing will be empty.
//
// TODO(kenton): See comment on TryConsumeEndOfDeclaration(), above, for
// why this is const.
void AttachComments(string* leading, string* trailing) const;
private:
Parser* parser_;
SourceCodeInfo::Location* location_;
void Init(const LocationRecorder& parent);
};
// =================================================================
// Parsers for various language constructs
// Parses the "syntax = \"proto2\";" line at the top of the file. Returns
// false if it failed to parse or if the syntax identifier was not
// recognized.
bool ParseSyntaxIdentifier();
// These methods parse various individual bits of code. They return
// false if they completely fail to parse the construct. In this case,
// it is probably necessary to skip the rest of the statement to recover.
// However, if these methods return true, it does NOT mean that there
// were no errors; only that there were no *syntax* errors. For instance,
// if a service method is defined using proper syntax but uses a primitive
// type as its input or output, ParseMethodField() still returns true
// and only reports the error by calling AddError(). In practice, this
// makes logic much simpler for the caller.
// Parse a top-level message, enum, service, etc.
bool ParseTopLevelStatement(FileDescriptorProto* file,
const LocationRecorder& root_location);
// Parse various language high-level language construrcts.
bool ParseMessageDefinition(DescriptorProto* message,
const LocationRecorder& message_location);
bool ParseEnumDefinition(EnumDescriptorProto* enum_type,
const LocationRecorder& enum_location);
bool ParseServiceDefinition(ServiceDescriptorProto* service,
const LocationRecorder& service_location);
bool ParsePackage(FileDescriptorProto* file,
const LocationRecorder& root_location);
bool ParseImport(RepeatedPtrField<string>* dependency,
RepeatedField<int32>* public_dependency,
RepeatedField<int32>* weak_dependency,
const LocationRecorder& root_location);
bool ParseOption(Message* options,
const LocationRecorder& options_location);
// These methods parse the contents of a message, enum, or service type and
// add them to the given object. They consume the entire block including
// the beginning and ending brace.
bool ParseMessageBlock(DescriptorProto* message,
const LocationRecorder& message_location);
bool ParseEnumBlock(EnumDescriptorProto* enum_type,
const LocationRecorder& enum_location);
bool ParseServiceBlock(ServiceDescriptorProto* service,
const LocationRecorder& service_location);
// Parse one statement within a message, enum, or service block, inclunding
// final semicolon.
bool ParseMessageStatement(DescriptorProto* message,
const LocationRecorder& message_location);
bool ParseEnumStatement(EnumDescriptorProto* message,
const LocationRecorder& enum_location);
bool ParseServiceStatement(ServiceDescriptorProto* message,
const LocationRecorder& service_location);
// Parse a field of a message. If the field is a group, its type will be
// added to "messages".
//
// parent_location and location_field_number_for_nested_type are needed when
// parsing groups -- we need to generate a nested message type within the
// parent and record its location accordingly. Since the parent could be
// either a FileDescriptorProto or a DescriptorProto, we must pass in the
// correct field number to use.
bool ParseMessageField(FieldDescriptorProto* field,
RepeatedPtrField<DescriptorProto>* messages,
const LocationRecorder& parent_location,
int location_field_number_for_nested_type,
const LocationRecorder& field_location);
// Parse an "extensions" declaration.
bool ParseExtensions(DescriptorProto* message,
const LocationRecorder& extensions_location);
// Parse an "extend" declaration. (See also comments for
// ParseMessageField().)
bool ParseExtend(RepeatedPtrField<FieldDescriptorProto>* extensions,
RepeatedPtrField<DescriptorProto>* messages,
const LocationRecorder& parent_location,
int location_field_number_for_nested_type,
const LocationRecorder& extend_location);
// Parse a single enum value within an enum block.
bool ParseEnumConstant(EnumValueDescriptorProto* enum_value,
const LocationRecorder& enum_value_location);
// Parse enum constant options, i.e. the list in square brackets at the end
// of the enum constant value definition.
bool ParseEnumConstantOptions(EnumValueDescriptorProto* value,
const LocationRecorder& enum_value_location);
// Parse a single method within a service definition.
bool ParseServiceMethod(MethodDescriptorProto* method,
const LocationRecorder& method_location);
// Parse options of a single method or stream.
bool ParseOptions(const LocationRecorder& parent_location,
const int optionsFieldNumber,
Message* mutable_options);
// Parse "required", "optional", or "repeated" and fill in "label"
// with the value.
bool ParseLabel(FieldDescriptorProto::Label* label);
// Parse a type name and fill in "type" (if it is a primitive) or
// "type_name" (if it is not) with the type parsed.
bool ParseType(FieldDescriptorProto::Type* type,
string* type_name);
// Parse a user-defined type and fill in "type_name" with the name.
// If a primitive type is named, it is treated as an error.
bool ParseUserDefinedType(string* type_name);
// Parses field options, i.e. the stuff in square brackets at the end
// of a field definition. Also parses default value.
bool ParseFieldOptions(FieldDescriptorProto* field,
const LocationRecorder& field_location);
// Parse the "default" option. This needs special handling because its
// type is the field's type.
bool ParseDefaultAssignment(FieldDescriptorProto* field,
const LocationRecorder& field_location);
enum OptionStyle {
OPTION_ASSIGNMENT, // just "name = value"
OPTION_STATEMENT // "option name = value;"
};
// Parse a single option name/value pair, e.g. "ctype = CORD". The name
// identifies a field of the given Message, and the value of that field
// is set to the parsed value.
bool ParseOption(Message* options,
const LocationRecorder& options_location,
OptionStyle style);
// Parses a single part of a multipart option name. A multipart name consists
// of names separated by dots. Each name is either an identifier or a series
// of identifiers separated by dots and enclosed in parentheses. E.g.,
// "foo.(bar.baz).qux".
bool ParseOptionNamePart(UninterpretedOption* uninterpreted_option,
const LocationRecorder& part_location);
// Parses a string surrounded by balanced braces. Strips off the outer
// braces and stores the enclosed string in *value.
// E.g.,
// { foo } *value gets 'foo'
// { foo { bar: box } } *value gets 'foo { bar: box }'
// {} *value gets ''
//
// REQUIRES: LookingAt("{")
// When finished successfully, we are looking at the first token past
// the ending brace.
bool ParseUninterpretedBlock(string* value);
// =================================================================
io::Tokenizer* input_;
io::ErrorCollector* error_collector_;
SourceCodeInfo* source_code_info_;
SourceLocationTable* source_location_table_; // legacy
bool had_errors_;
bool require_syntax_identifier_;
bool stop_after_syntax_identifier_;
string syntax_identifier_;
// Leading doc comments for the next declaration. These are not complete
// yet; use ConsumeEndOfDeclaration() to get the complete comments.
string upcoming_doc_comments_;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Parser);
};
// A table mapping (descriptor, ErrorLocation) pairs -- as reported by
// DescriptorPool when validating descriptors -- to line and column numbers
// within the original source code.
//
// This is semi-obsolete: FileDescriptorProto.source_code_info now contains
// far more complete information about source locations. However, as of this
// writing you still need to use SourceLocationTable when integrating with
// DescriptorPool.
class LIBPROTOBUF_EXPORT SourceLocationTable {
public:
SourceLocationTable();
~SourceLocationTable();
// Finds the precise location of the given error and fills in *line and
// *column with the line and column numbers. If not found, sets *line to
// -1 and *column to 0 (since line = -1 is used to mean "error has no exact
// location" in the ErrorCollector interface). Returns true if found, false
// otherwise.
bool Find(const Message* descriptor,
DescriptorPool::ErrorCollector::ErrorLocation location,
int* line, int* column) const;
// Adds a location to the table.
void Add(const Message* descriptor,
DescriptorPool::ErrorCollector::ErrorLocation location,
int line, int column);
// Clears the contents of the table.
void Clear();
private:
typedef map<
pair<const Message*, DescriptorPool::ErrorCollector::ErrorLocation>,
pair<int, int> > LocationMap;
LocationMap location_map_;
};
} // namespace compiler
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_COMPILER_PARSER_H__