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// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SRC_READER_WGSL_PARSER_IMPL_H_
#define SRC_READER_WGSL_PARSER_IMPL_H_
#include <deque>
#include <memory>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
#include "src/ast/access.h"
#include "src/program_builder.h"
#include "src/reader/wgsl/parser_impl_detail.h"
#include "src/reader/wgsl/token.h"
#include "src/sem/storage_texture_type.h"
namespace tint {
namespace ast {
class AssignmentStatement;
class BreakStatement;
class CallStatement;
class ContinueStatement;
class IfStatement;
class LoopStatement;
class ReturnStatement;
class SwitchStatement;
class VariableDeclStatement;
} // namespace ast
namespace reader {
namespace wgsl {
class Lexer;
/// Struct holding information for a for loop
struct ForHeader {
/// Constructor
/// @param init the initializer statement
/// @param cond the condition statement
/// @param cont the continuing statement
ForHeader(const ast::Statement* init,
const ast::Expression* cond,
const ast::Statement* cont);
~ForHeader();
/// The for loop initializer
const ast::Statement* initializer = nullptr;
/// The for loop condition
const ast::Expression* condition = nullptr;
/// The for loop continuing statement
const ast::Statement* continuing = nullptr;
};
/// ParserImpl for WGSL source data
class ParserImpl {
/// Failure holds enumerator values used for the constructing an Expect and
/// Match in an errored state.
struct Failure {
enum Errored { kErrored };
enum NoMatch { kNoMatch };
};
public:
/// Expect is the return type of the parser methods that are expected to
/// return a parsed value of type T, unless there was an parse error.
/// In the case of a parse error the called method will have called
/// add_error() and #errored will be set to true.
template <typename T>
struct Expect {
/// An alias to the templated type T.
using type = T;
/// Don't allow an Expect to take a nullptr.
inline Expect(std::nullptr_t) = delete; // NOLINT
/// Constructor for a successful parse.
/// @param val the result value of the parse
/// @param s the optional source of the value
template <typename U>
inline Expect(U&& val, const Source& s = {}) // NOLINT
: value(std::forward<U>(val)), source(s) {}
/// Constructor for parse error.
inline Expect(Failure::Errored) : errored(true) {} // NOLINT
/// Copy constructor
inline Expect(const Expect&) = default;
/// Move constructor
inline Expect(Expect&&) = default;
/// Assignment operator
/// @return this Expect
inline Expect& operator=(const Expect&) = default;
/// Assignment move operator
/// @return this Expect
inline Expect& operator=(Expect&&) = default;
/// @return a pointer to the returned value. If T is a pointer or
/// std::unique_ptr, operator->() automatically dereferences so that the
/// return type will always be a pointer to a non-pointer type. #errored
/// must be false to call.
inline typename detail::OperatorArrow<T>::type operator->() {
TINT_ASSERT(Reader, !errored);
return detail::OperatorArrow<T>::ptr(value);
}
/// The expected value of a successful parse.
/// Zero-initialized when there was a parse error.
T value{};
/// Optional source of the value.
Source source;
/// True if there was a error parsing.
bool errored = false;
};
/// Maybe is the return type of the parser methods that attempts to match a
/// grammar and return a parsed value of type T, or may parse part of the
/// grammar and then hit a parse error.
/// In the case of a successful grammar match, the Maybe will have #matched
/// set to true.
/// In the case of a parse error the called method will have called
/// add_error() and the Maybe will have #errored set to true.
template <typename T>
struct Maybe {
inline Maybe(std::nullptr_t) = delete; // NOLINT
/// Constructor for a successful parse.
/// @param val the result value of the parse
/// @param s the optional source of the value
template <typename U>
inline Maybe(U&& val, const Source& s = {}) // NOLINT
: value(std::forward<U>(val)), source(s), matched(true) {}
/// Constructor for parse error state.
inline Maybe(Failure::Errored) : errored(true) {} // NOLINT
/// Constructor for the no-match state.
inline Maybe(Failure::NoMatch) {} // NOLINT
/// Constructor from an Expect.
/// @param e the Expect to copy this Maybe from
template <typename U>
inline Maybe(const Expect<U>& e) // NOLINT
: value(e.value),
source(e.value),
errored(e.errored),
matched(!e.errored) {}
/// Move from an Expect.
/// @param e the Expect to move this Maybe from
template <typename U>
inline Maybe(Expect<U>&& e) // NOLINT
: value(std::move(e.value)),
source(std::move(e.source)),
errored(e.errored),
matched(!e.errored) {}
/// Copy constructor
inline Maybe(const Maybe&) = default;
/// Move constructor
inline Maybe(Maybe&&) = default;
/// Assignment operator
/// @return this Maybe
inline Maybe& operator=(const Maybe&) = default;
/// Assignment move operator
/// @return this Maybe
inline Maybe& operator=(Maybe&&) = default;
/// @return a pointer to the returned value. If T is a pointer or
/// std::unique_ptr, operator->() automatically dereferences so that the
/// return type will always be a pointer to a non-pointer type. #errored
/// must be false to call.
inline typename detail::OperatorArrow<T>::type operator->() {
TINT_ASSERT(Reader, !errored);
return detail::OperatorArrow<T>::ptr(value);
}
/// The value of a successful parse.
/// Zero-initialized when there was a parse error.
T value{};
/// Optional source of the value.
Source source;
/// True if there was a error parsing.
bool errored = false;
/// True if there was a error parsing.
bool matched = false;
};
/// TypedIdentifier holds a parsed identifier and type. Returned by
/// variable_ident_decl().
struct TypedIdentifier {
/// Constructor
TypedIdentifier();
/// Copy constructor
/// @param other the FunctionHeader to copy
TypedIdentifier(const TypedIdentifier& other);
/// Constructor
/// @param type_in parsed type
/// @param name_in parsed identifier
/// @param source_in source to the identifier
TypedIdentifier(const ast::Type* type_in,
std::string name_in,
Source source_in);
/// Destructor
~TypedIdentifier();
/// Parsed type. May be nullptr for inferred types.
const ast::Type* type = nullptr;
/// Parsed identifier.
std::string name;
/// Source to the identifier.
Source source;
};
/// FunctionHeader contains the parsed information for a function header.
struct FunctionHeader {
/// Constructor
FunctionHeader();
/// Copy constructor
/// @param other the FunctionHeader to copy
FunctionHeader(const FunctionHeader& other);
/// Constructor
/// @param src parsed header source
/// @param n function name
/// @param p function parameters
/// @param ret_ty function return type
/// @param ret_decos return type decorations
FunctionHeader(Source src,
std::string n,
ast::VariableList p,
const ast::Type* ret_ty,
ast::DecorationList ret_decos);
/// Destructor
~FunctionHeader();
/// Assignment operator
/// @param other the FunctionHeader to copy
/// @returns this FunctionHeader
FunctionHeader& operator=(const FunctionHeader& other);
/// Parsed header source
Source source;
/// Function name
std::string name;
/// Function parameters
ast::VariableList params;
/// Function return type
const ast::Type* return_type = nullptr;
/// Function return type decorations
ast::DecorationList return_type_decorations;
};
/// VarDeclInfo contains the parsed information for variable declaration.
struct VarDeclInfo {
/// Constructor
VarDeclInfo();
/// Copy constructor
/// @param other the VarDeclInfo to copy
VarDeclInfo(const VarDeclInfo& other);
/// Constructor
/// @param source_in variable declaration source
/// @param name_in variable name
/// @param storage_class_in variable storage class
/// @param access_in variable access control
/// @param type_in variable type
VarDeclInfo(Source source_in,
std::string name_in,
ast::StorageClass storage_class_in,
ast::Access access_in,
const ast::Type* type_in);
/// Destructor
~VarDeclInfo();
/// Variable declaration source
Source source;
/// Variable name
std::string name;
/// Variable storage class
ast::StorageClass storage_class = ast::StorageClass::kNone;
/// Variable access control
ast::Access access = ast::Access::kUndefined;
/// Variable type
const ast::Type* type = nullptr;
};
/// VariableQualifier contains the parsed information for a variable qualifier
struct VariableQualifier {
/// The variable's storage class
ast::StorageClass storage_class = ast::StorageClass::kNone;
/// The variable's access control
ast::Access access = ast::Access::kUndefined;
};
/// Creates a new parser using the given file
/// @param file the input source file to parse
explicit ParserImpl(Source::File const* file);
~ParserImpl();
/// Run the parser
/// @returns true if the parse was successful, false otherwise.
bool Parse();
/// set_max_diagnostics sets the maximum number of reported errors before
/// aborting parsing.
/// @param limit the new maximum number of errors
void set_max_errors(size_t limit) { max_errors_ = limit; }
/// @return the number of maximum number of reported errors before aborting
/// parsing.
size_t get_max_errors() const { return max_errors_; }
/// @returns true if an error was encountered.
bool has_error() const { return builder_.Diagnostics().contains_errors(); }
/// @returns the parser error string
std::string error() const {
diag::Formatter formatter{{false, false, false, false}};
return formatter.format(builder_.Diagnostics());
}
/// @returns the Program. The program builder in the parser will be reset
/// after this.
Program program() { return Program(std::move(builder_)); }
/// @returns the program builder.
ProgramBuilder& builder() { return builder_; }
/// @returns the next token
Token next();
/// Peeks ahead and returns the token at `idx` ahead of the current position
/// @param idx the index of the token to return
/// @returns the token `idx` positions ahead without advancing
Token peek(size_t idx = 0);
/// Peeks ahead and returns true if the token at `idx` ahead of the current
/// position is |tok|
/// @param idx the index of the token to return
/// @param tok the token to look for
/// @returns true if the token `idx` positions ahead is |tok|
bool peek_is(Token::Type tok, size_t idx = 0);
/// @returns the last token that was returned by `next()`
Token last_token() const;
/// Appends an error at `t` with the message `msg`
/// @param t the token to associate the error with
/// @param msg the error message
/// @return `Failure::Errored::kError` so that you can combine an add_error()
/// call and return on the same line.
Failure::Errored add_error(const Token& t, const std::string& msg);
/// Appends an error raised when parsing `use` at `t` with the message
/// `msg`
/// @param source the source to associate the error with
/// @param msg the error message
/// @param use a description of what was being parsed when the error was
/// raised.
/// @return `Failure::Errored::kError` so that you can combine an add_error()
/// call and return on the same line.
Failure::Errored add_error(const Source& source,
const std::string& msg,
const std::string& use);
/// Appends an error at `source` with the message `msg`
/// @param source the source to associate the error with
/// @param msg the error message
/// @return `Failure::Errored::kError` so that you can combine an add_error()
/// call and return on the same line.
Failure::Errored add_error(const Source& source, const std::string& msg);
/// Appends a deprecated-language-feature warning at `source` with the message
/// `msg`
/// @param source the source to associate the error with
/// @param msg the warning message
void deprecated(const Source& source, const std::string& msg);
/// Parses the `translation_unit` grammar element
void translation_unit();
/// Parses the `global_decl` grammar element, erroring on parse failure.
/// @return true on parse success, otherwise an error.
Expect<bool> expect_global_decl();
/// Parses a `global_variable_decl` grammar element with the initial
/// `variable_decoration_list*` provided as `decos`
/// @returns the variable parsed or nullptr
/// @param decos the list of decorations for the variable declaration.
Maybe<const ast::Variable*> global_variable_decl(ast::DecorationList& decos);
/// Parses a `global_constant_decl` grammar element with the initial
/// `variable_decoration_list*` provided as `decos`
/// @returns the const object or nullptr
/// @param decos the list of decorations for the constant declaration.
Maybe<const ast::Variable*> global_constant_decl(ast::DecorationList& decos);
/// Parses a `variable_decl` grammar element
/// @param allow_inferred if true, do not fail if variable decl does not
/// specify type
/// @returns the parsed variable declaration info
Maybe<VarDeclInfo> variable_decl(bool allow_inferred = false);
/// Parses a `variable_ident_decl` grammar element, erroring on parse
/// failure.
/// @param use a description of what was being parsed if an error was raised.
/// @param allow_inferred if true, do not fail if variable decl does not
/// specify type
/// @returns the identifier and type parsed or empty otherwise
Expect<TypedIdentifier> expect_variable_ident_decl(
const std::string& use,
bool allow_inferred = false);
/// Parses a `variable_qualifier` grammar element
/// @returns the variable qualifier information
Maybe<VariableQualifier> variable_qualifier();
/// Parses a `type_alias` grammar element
/// @returns the type alias or nullptr on error
Maybe<const ast::Alias*> type_alias();
/// Parses a `type_decl` grammar element
/// @returns the parsed Type or nullptr if none matched.
Maybe<const ast::Type*> type_decl();
/// Parses a `type_decl` grammar element with the given pre-parsed
/// decorations.
/// @param decos the list of decorations for the type.
/// @returns the parsed Type or nullptr if none matched.
Maybe<const ast::Type*> type_decl(ast::DecorationList& decos);
/// Parses a `storage_class` grammar element, erroring on parse failure.
/// @param use a description of what was being parsed if an error was raised.
/// @returns the storage class or StorageClass::kNone if none matched
Expect<ast::StorageClass> expect_storage_class(const std::string& use);
/// Parses a `struct_decl` grammar element with the initial
/// `struct_decoration_decl*` provided as `decos`.
/// @returns the struct type or nullptr on error
/// @param decos the list of decorations for the struct declaration.
Maybe<const ast::Struct*> struct_decl(ast::DecorationList& decos);
/// Parses a `struct_body_decl` grammar element, erroring on parse failure.
/// @returns the struct members
Expect<ast::StructMemberList> expect_struct_body_decl();
/// Parses a `struct_member` grammar element with the initial
/// `struct_member_decoration_decl+` provided as `decos`, erroring on parse
/// failure.
/// @param decos the list of decorations for the struct member.
/// @returns the struct member or nullptr
Expect<ast::StructMember*> expect_struct_member(ast::DecorationList& decos);
/// Parses a `function_decl` grammar element with the initial
/// `function_decoration_decl*` provided as `decos`.
/// @param decos the list of decorations for the function declaration.
/// @returns the parsed function, nullptr otherwise
Maybe<const ast::Function*> function_decl(ast::DecorationList& decos);
/// Parses a `texture_sampler_types` grammar element
/// @returns the parsed Type or nullptr if none matched.
Maybe<const ast::Type*> texture_sampler_types();
/// Parses a `sampler_type` grammar element
/// @returns the parsed Type or nullptr if none matched.
Maybe<const ast::Type*> sampler_type();
/// Parses a `multisampled_texture_type` grammar element
/// @returns returns the multisample texture dimension or kNone if none
/// matched.
Maybe<const ast::TextureDimension> multisampled_texture_type();
/// Parses a `sampled_texture_type` grammar element
/// @returns returns the sample texture dimension or kNone if none matched.
Maybe<const ast::TextureDimension> sampled_texture_type();
/// Parses a `storage_texture_type` grammar element
/// @returns returns the storage texture dimension.
/// Returns kNone if none matched.
Maybe<const ast::TextureDimension> storage_texture_type();
/// Parses a `depth_texture_type` grammar element
/// @returns the parsed Type or nullptr if none matched.
Maybe<const ast::Type*> depth_texture_type();
/// Parses a 'texture_external_type' grammar element
/// @returns the parsed Type or nullptr if none matched
Maybe<const ast::Type*> external_texture_type();
/// Parses a `image_storage_type` grammar element
/// @param use a description of what was being parsed if an error was raised
/// @returns returns the image format or kNone if none matched.
Expect<ast::ImageFormat> expect_image_storage_type(const std::string& use);
/// Parses a `function_header` grammar element
/// @returns the parsed function header
Maybe<FunctionHeader> function_header();
/// Parses a `param_list` grammar element, erroring on parse failure.
/// @returns the parsed variables
Expect<ast::VariableList> expect_param_list();
/// Parses a `param` grammar element, erroring on parse failure.
/// @returns the parsed variable
Expect<ast::Variable*> expect_param();
/// Parses a `pipeline_stage` grammar element, erroring if the next token does
/// not match a stage name.
/// @returns the pipeline stage.
Expect<ast::PipelineStage> expect_pipeline_stage();
/// Parses an access control identifier, erroring if the next token does not
/// match a valid access control.
/// @param use a description of what was being parsed if an error was raised
/// @returns the parsed access control.
Expect<ast::Access> expect_access(const std::string& use);
/// Parses a builtin identifier, erroring if the next token does not match a
/// valid builtin name.
/// @returns the parsed builtin.
Expect<ast::Builtin> expect_builtin();
/// Parses a `body_stmt` grammar element, erroring on parse failure.
/// @returns the parsed statements
Expect<ast::BlockStatement*> expect_body_stmt();
/// Parses a `paren_rhs_stmt` grammar element, erroring on parse failure.
/// @returns the parsed element or nullptr
Expect<const ast::Expression*> expect_paren_rhs_stmt();
/// Parses a `statements` grammar element
/// @returns the statements parsed
Expect<ast::StatementList> expect_statements();
/// Parses a `statement` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::Statement*> statement();
/// Parses a `break_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::BreakStatement*> break_stmt();
/// Parses a `return_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::ReturnStatement*> return_stmt();
/// Parses a `continue_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::ContinueStatement*> continue_stmt();
/// Parses a `variable_stmt` grammar element
/// @returns the parsed variable or nullptr
Maybe<const ast::VariableDeclStatement*> variable_stmt();
/// Parses a `if_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::IfStatement*> if_stmt();
/// Parses a `elseif_stmt` grammar element
/// @returns the parsed elements
Maybe<ast::ElseStatementList> elseif_stmt();
/// Parses a `else_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::ElseStatement*> else_stmt();
/// Parses a `switch_stmt` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::SwitchStatement*> switch_stmt();
/// Parses a `switch_body` grammar element
/// @returns the parsed statement or nullptr
Maybe<const ast::CaseStatement*> switch_body();
/// Parses a `case_selectors` grammar element
/// @returns the list of literals
Expect<ast::CaseSelectorList> expect_case_selectors();
/// Parses a `case_body` grammar element
/// @returns the parsed statements
Maybe<const ast::BlockStatement*> case_body();
/// Parses a `func_call_stmt` grammar element
/// @returns the parsed function call or nullptr
Maybe<const ast::CallStatement*> func_call_stmt();
/// Parses a `loop_stmt` grammar element
/// @returns the parsed loop or nullptr
Maybe<const ast::LoopStatement*> loop_stmt();
/// Parses a `for_header` grammar element, erroring on parse failure.
/// @returns the parsed for header or nullptr
Expect<std::unique_ptr<ForHeader>> expect_for_header();
/// Parses a `for_stmt` grammar element
/// @returns the parsed for loop or nullptr
Maybe<const ast::ForLoopStatement*> for_stmt();
/// Parses a `continuing_stmt` grammar element
/// @returns the parsed statements
Maybe<const ast::BlockStatement*> continuing_stmt();
/// Parses a `const_literal` grammar element
/// @returns the const literal parsed or nullptr if none found
Maybe<const ast::LiteralExpression*> const_literal();
/// Parses a `const_expr` grammar element, erroring on parse failure.
/// @returns the parsed constructor expression or nullptr on error
Expect<const ast::Expression*> expect_const_expr();
/// Parses a `primary_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> primary_expression();
/// Parses a `argument_expression_list` grammar element, erroring on parse
/// failure.
/// @param use a description of what was being parsed if an error was raised
/// @returns the list of arguments
Expect<ast::ExpressionList> expect_argument_expression_list(
const std::string& use);
/// Parses the recursive portion of the postfix_expression
/// @param prefix the left side of the expression
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> postfix_expression(
const ast::Expression* prefix);
/// Parses a `singular_expression` grammar elment
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> singular_expression();
/// Parses a `unary_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> unary_expression();
/// Parses the recursive part of the `multiplicative_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_multiplicative_expr(
const ast::Expression* lhs);
/// Parses the `multiplicative_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> multiplicative_expression();
/// Parses the recursive part of the `additive_expression`, erroring on parse
/// failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_additive_expr(
const ast::Expression* lhs);
/// Parses the `additive_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> additive_expression();
/// Parses the recursive part of the `shift_expression`, erroring on parse
/// failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_shift_expr(const ast::Expression* lhs);
/// Parses the `shift_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> shift_expression();
/// Parses the recursive part of the `relational_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_relational_expr(
const ast::Expression* lhs);
/// Parses the `relational_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> relational_expression();
/// Parses the recursive part of the `equality_expression`, erroring on parse
/// failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_equality_expr(
const ast::Expression* lhs);
/// Parses the `equality_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> equality_expression();
/// Parses the recursive part of the `and_expression`, erroring on parse
/// failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_and_expr(const ast::Expression* lhs);
/// Parses the `and_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> and_expression();
/// Parses the recursive part of the `exclusive_or_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_exclusive_or_expr(
const ast::Expression* lhs);
/// Parses the `exclusive_or_expression` grammar elememnt
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> exclusive_or_expression();
/// Parses the recursive part of the `inclusive_or_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_inclusive_or_expr(
const ast::Expression* lhs);
/// Parses the `inclusive_or_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> inclusive_or_expression();
/// Parses the recursive part of the `logical_and_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_logical_and_expr(
const ast::Expression* lhs);
/// Parses a `logical_and_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> logical_and_expression();
/// Parses the recursive part of the `logical_or_expression`, erroring on
/// parse failure.
/// @param lhs the left side of the expression
/// @returns the parsed expression or nullptr
Expect<const ast::Expression*> expect_logical_or_expr(
const ast::Expression* lhs);
/// Parses a `logical_or_expression` grammar element
/// @returns the parsed expression or nullptr
Maybe<const ast::Expression*> logical_or_expression();
/// Parses a `assignment_stmt` grammar element
/// @returns the parsed assignment or nullptr
Maybe<const ast::AssignmentStatement*> assignment_stmt();
/// Parses one or more bracketed decoration lists.
/// @return the parsed decoration list, or an empty list on error.
Maybe<ast::DecorationList> decoration_list();
/// Parses a list of decorations between `ATTR_LEFT` and `ATTR_RIGHT`
/// brackets.
/// @param decos the list to append newly parsed decorations to.
/// @return true if any decorations were be parsed, otherwise false.
Maybe<bool> decoration_bracketed_list(ast::DecorationList& decos);
/// Parses a single decoration of the following types:
/// * `struct_decoration`
/// * `struct_member_decoration`
/// * `array_decoration`
/// * `variable_decoration`
/// * `global_const_decoration`
/// * `function_decoration`
/// @return the parsed decoration, or nullptr.
Maybe<const ast::Decoration*> decoration();
/// Parses a single decoration, reporting an error if the next token does not
/// represent a decoration.
/// @see #decoration for the full list of decorations this method parses.
/// @return the parsed decoration, or nullptr on error.
Expect<const ast::Decoration*> expect_decoration();
private:
/// ReturnType resolves to the return type for the function or lambda F.
template <typename F>
using ReturnType = typename std::result_of<F()>::type;
/// ResultType resolves to `T` for a `RESULT` of type Expect<T>.
template <typename RESULT>
using ResultType = typename RESULT::type;
/// @returns true and consumes the next token if it equals `tok`
/// @param source if not nullptr, the next token's source is written to this
/// pointer, regardless of success or error
bool match(Token::Type tok, Source* source = nullptr);
/// Errors if the next token is not equal to `tok`
/// Consumes the next token on match.
/// expect() also updates #synchronized_, setting it to `true` if the next
/// token is equal to `tok`, otherwise `false`.
/// @param use a description of what was being parsed if an error was raised.
/// @param tok the token to test against
/// @returns true if the next token equals `tok`
bool expect(const std::string& use, Token::Type tok);
/// Parses a signed integer from the next token in the stream, erroring if the
/// next token is not a signed integer.
/// Consumes the next token on match.
/// @param use a description of what was being parsed if an error was raised
/// @returns the parsed integer.
Expect<int32_t> expect_sint(const std::string& use);
/// Parses a signed integer from the next token in the stream, erroring if
/// the next token is not a signed integer or is negative.
/// Consumes the next token if it is a signed integer (not necessarily
/// negative).
/// @param use a description of what was being parsed if an error was raised
/// @returns the parsed integer.
Expect<uint32_t> expect_positive_sint(const std::string& use);
/// Parses a non-zero signed integer from the next token in the stream,
/// erroring if the next token is not a signed integer or is less than 1.
/// Consumes the next token if it is a signed integer (not necessarily
/// >= 1).
/// @param use a description of what was being parsed if an error was raised
/// @returns the parsed integer.
Expect<uint32_t> expect_nonzero_positive_sint(const std::string& use);
/// Errors if the next token is not an identifier.
/// Consumes the next token on match.
/// @param use a description of what was being parsed if an error was raised
/// @returns the parsed identifier.
Expect<std::string> expect_ident(const std::string& use);
/// Parses a lexical block starting with the token `start` and ending with
/// the token `end`. `body` is called to parse the lexical block body
/// between the `start` and `end` tokens. If the `start` or `end` tokens
/// are not matched then an error is generated and a zero-initialized `T` is
/// returned. If `body` raises an error while parsing then a zero-initialized
/// `T` is returned.
/// @param start the token that begins the lexical block
/// @param end the token that ends the lexical block
/// @param use a description of what was being parsed if an error was raised
/// @param body a function or lambda that is called to parse the lexical block
/// body, with the signature: `Expect<Result>()` or `Maybe<Result>()`.
/// @return the value returned by `body` if no errors are raised, otherwise
/// an Expect with error state.
template <typename F, typename T = ReturnType<F>>
T expect_block(Token::Type start,
Token::Type end,
const std::string& use,
F&& body);
/// A convenience function that calls expect_block() passing
/// `Token::Type::kParenLeft` and `Token::Type::kParenRight` for the `start`
/// and `end` arguments, respectively.
/// @param use a description of what was being parsed if an error was raised
/// @param body a function or lambda that is called to parse the lexical block
/// body, with the signature: `Expect<Result>()` or `Maybe<Result>()`.
/// @return the value returned by `body` if no errors are raised, otherwise
/// an Expect with error state.
template <typename F, typename T = ReturnType<F>>
T expect_paren_block(const std::string& use, F&& body);
/// A convenience function that calls `expect_block` passing
/// `Token::Type::kBraceLeft` and `Token::Type::kBraceRight` for the `start`
/// and `end` arguments, respectively.
/// @param use a description of what was being parsed if an error was raised
/// @param body a function or lambda that is called to parse the lexical block
/// body, with the signature: `Expect<Result>()` or `Maybe<Result>()`.
/// @return the value returned by `body` if no errors are raised, otherwise
/// an Expect with error state.
template <typename F, typename T = ReturnType<F>>
T expect_brace_block(const std::string& use, F&& body);
/// A convenience function that calls `expect_block` passing
/// `Token::Type::kLessThan` and `Token::Type::kGreaterThan` for the `start`
/// and `end` arguments, respectively.
/// @param use a description of what was being parsed if an error was raised
/// @param body a function or lambda that is called to parse the lexical block
/// body, with the signature: `Expect<Result>()` or `Maybe<Result>()`.
/// @return the value returned by `body` if no errors are raised, otherwise
/// an Expect with error state.
template <typename F, typename T = ReturnType<F>>
T expect_lt_gt_block(const std::string& use, F&& body);
/// sync() calls the function `func`, and attempts to resynchronize the
/// parser to the next found resynchronization token if `func` fails. If the
/// next found resynchronization token is `tok`, then sync will also consume
/// `tok`.
///
/// sync() will transiently add `tok` to the parser's stack of
/// synchronization tokens for the duration of the call to `func`. Once @p
/// func returns,
/// `tok` is removed from the stack of resynchronization tokens. sync calls
/// may be nested, and so the number of resynchronization tokens is equal to
/// the number of sync() calls in the current stack frame.
///
/// sync() updates #synchronized_, setting it to `true` if the next
/// resynchronization token found was `tok`, otherwise `false`.
///
/// @param tok the token to attempt to synchronize the parser to if `func`
/// fails.
/// @param func a function or lambda with the signature: `Expect<Result>()` or
/// `Maybe<Result>()`.
/// @return the value returned by `func`
template <typename F, typename T = ReturnType<F>>
T sync(Token::Type tok, F&& func);
/// sync_to() attempts to resynchronize the parser to the next found
/// resynchronization token or `tok` (whichever comes first).
///
/// Synchronization tokens are transiently defined by calls to sync().
///
/// sync_to() updates #synchronized_, setting it to `true` if a
/// resynchronization token was found and it was `tok`, otherwise `false`.
///
/// @param tok the token to attempt to synchronize the parser to.
/// @param consume if true and the next found resynchronization token is
/// `tok` then sync_to() will also consume `tok`.
/// @return the state of #synchronized_.
/// @see sync().
bool sync_to(Token::Type tok, bool consume);
/// @return true if `t` is in the stack of resynchronization tokens.
/// @see sync().
bool is_sync_token(const Token& t) const;
/// @returns true if #synchronized_ is true and the number of reported errors
/// is less than #max_errors_.
bool continue_parsing() {
return synchronized_ && builder_.Diagnostics().error_count() < max_errors_;
}
/// without_error() calls the function `func` muting any grammatical errors
/// found while executing the function. This can be used as a best-effort to
/// produce a meaningful error message when the parser is out of sync.
/// @param func a function or lambda with the signature: `Expect<Result>()` or
/// `Maybe<Result>()`.
/// @return the value returned by `func`
template <typename F, typename T = ReturnType<F>>
T without_error(F&& func);
/// Reports an error if the decoration list `list` is not empty.
/// Used to ensure that all decorations are consumed.
bool expect_decorations_consumed(ast::DecorationList& list);
Expect<const ast::Type*> expect_type_decl_pointer(Token t);
Expect<const ast::Type*> expect_type_decl_atomic(Token t);
Expect<const ast::Type*> expect_type_decl_vector(Token t);
Expect<const ast::Type*> expect_type_decl_array(Token t,
ast::DecorationList decos);
Expect<const ast::Type*> expect_type_decl_matrix(Token t);
Expect<const ast::Type*> expect_type(const std::string& use);
Maybe<const ast::Statement*> non_block_statement();
Maybe<const ast::Statement*> for_header_initializer();
Maybe<const ast::Statement*> for_header_continuing();
class MultiTokenSource;
MultiTokenSource make_source_range();
MultiTokenSource make_source_range_from(const Source& start);
/// Creates a new `ast::Node` owned by the Module. When the Module is
/// destructed, the `ast::Node` will also be destructed.
/// @param args the arguments to pass to the type constructor
/// @returns the node pointer
template <typename T, typename... ARGS>
T* create(ARGS&&... args) {
return builder_.create<T>(std::forward<ARGS>(args)...);
}
std::unique_ptr<Lexer> lexer_;
std::deque<Token> token_queue_;
Token last_token_;
bool synchronized_ = true;
uint32_t parse_depth_ = 0;
std::vector<Token::Type> sync_tokens_;
int silence_errors_ = 0;
ProgramBuilder builder_;
size_t max_errors_ = 25;
};
} // namespace wgsl
} // namespace reader
} // namespace tint
#endif // SRC_READER_WGSL_PARSER_IMPL_H_