// Copyright (C) 2020-2024 Free Software Foundation, Inc.
// This file is part of GCC.
// GCC is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3, or (at your option) any later
// version.
// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
// You should have received a copy of the GNU General Public License
// along with GCC; see the file COPYING3. If not see
// .
#ifndef RUST_AST_STATEMENT_H
#define RUST_AST_STATEMENT_H
#include "rust-ast.h"
#include "rust-path.h"
#include "rust-expr.h"
namespace Rust {
namespace AST {
// Just a semi-colon, which apparently is a statement.
class EmptyStmt : public Stmt
{
location_t locus;
// TODO: find another way to store this to save memory?
bool marked_for_strip = false;
public:
std::string as_string () const override { return std::string (1, ';'); }
EmptyStmt (location_t locus) : locus (locus) {}
location_t get_locus () const override final { return locus; }
void accept_vis (ASTVisitor &vis) override;
// Can't think of any invalid invariants, so store boolean.
void mark_for_strip () override { marked_for_strip = true; }
bool is_marked_for_strip () const override { return marked_for_strip; }
bool is_item () const override final { return false; }
Stmt::Kind get_stmt_kind () final { return Stmt::Kind::Empty; }
protected:
/* Use covariance to implement clone function as returning this object rather
* than base */
EmptyStmt *clone_stmt_impl () const override { return new EmptyStmt (*this); }
};
/* Variable assignment let statement - type of "declaration statement" as it
* introduces new name into scope */
class LetStmt : public Stmt
{
// bool has_outer_attrs;
std::vector outer_attrs;
std::unique_ptr variables_pattern;
// bool has_type;
std::unique_ptr type;
// bool has_init_expr;
std::unique_ptr init_expr;
location_t locus;
public:
Type *inferedType;
// Returns whether let statement has outer attributes.
bool has_outer_attrs () const { return !outer_attrs.empty (); }
// Returns whether let statement has a given return type.
bool has_type () const { return type != nullptr; }
// Returns whether let statement has an initialisation expression.
bool has_init_expr () const { return init_expr != nullptr; }
std::string as_string () const override;
LetStmt (std::unique_ptr variables_pattern,
std::unique_ptr init_expr, std::unique_ptr type,
std::vector outer_attrs, location_t locus)
: outer_attrs (std::move (outer_attrs)),
variables_pattern (std::move (variables_pattern)),
type (std::move (type)), init_expr (std::move (init_expr)), locus (locus)
{}
// Copy constructor with clone
LetStmt (LetStmt const &other)
: outer_attrs (other.outer_attrs), locus (other.locus)
{
// guard to prevent null dereference (only required if error state)
if (other.variables_pattern != nullptr)
variables_pattern = other.variables_pattern->clone_pattern ();
// guard to prevent null dereference (always required)
if (other.init_expr != nullptr)
init_expr = other.init_expr->clone_expr ();
if (other.type != nullptr)
type = other.type->clone_type ();
}
// Overloaded assignment operator to clone
LetStmt &operator= (LetStmt const &other)
{
outer_attrs = other.outer_attrs;
locus = other.locus;
// guard to prevent null dereference (only required if error state)
if (other.variables_pattern != nullptr)
variables_pattern = other.variables_pattern->clone_pattern ();
else
variables_pattern = nullptr;
// guard to prevent null dereference (always required)
if (other.init_expr != nullptr)
init_expr = other.init_expr->clone_expr ();
else
init_expr = nullptr;
if (other.type != nullptr)
type = other.type->clone_type ();
else
type = nullptr;
return *this;
}
// move constructors
LetStmt (LetStmt &&other) = default;
LetStmt &operator= (LetStmt &&other) = default;
location_t get_locus () const override final { return locus; }
void accept_vis (ASTVisitor &vis) override;
// Invalid if pattern is null, so base stripping on that.
void mark_for_strip () override { variables_pattern = nullptr; }
bool is_marked_for_strip () const override
{
return variables_pattern == nullptr;
}
// TODO: this mutable getter seems really dodgy. Think up better way.
std::vector &get_outer_attrs () { return outer_attrs; }
const std::vector &get_outer_attrs () const { return outer_attrs; }
// TODO: is this better? Or is a "vis_block" better?
std::unique_ptr &get_init_expr ()
{
rust_assert (has_init_expr ());
return init_expr;
}
std::unique_ptr &get_pattern ()
{
rust_assert (variables_pattern != nullptr);
return variables_pattern;
}
std::unique_ptr &get_type ()
{
rust_assert (has_type ());
return type;
}
bool is_item () const override final { return false; }
Stmt::Kind get_stmt_kind () final { return Stmt::Kind::Let; }
protected:
/* Use covariance to implement clone function as returning this object rather
* than base */
LetStmt *clone_stmt_impl () const override { return new LetStmt (*this); }
};
// Expression statements (statements containing an expression)
class ExprStmt : public Stmt
{
std::unique_ptr expr;
location_t locus;
bool semicolon_followed;
public:
location_t get_locus () const override final { return locus; }
bool is_item () const override final { return false; }
bool is_expr () const override final { return true; }
// Used for the last statement for statement macros with a trailing
// semicolon.
void add_semicolon () override final { semicolon_followed = true; }
std::string as_string () const override;
Stmt::Kind get_stmt_kind () final { return Stmt::Kind::Expr; }
std::vector locals;
ExprStmt (std::unique_ptr &&expr, location_t locus,
bool semicolon_followed)
: expr (std::move (expr)), locus (locus),
semicolon_followed (semicolon_followed)
{}
// Copy constructor with clone
ExprStmt (ExprStmt const &other)
: locus (other.locus), semicolon_followed (other.semicolon_followed)
{
// guard to prevent null dereference (only required if error state)
if (other.expr != nullptr)
expr = other.expr->clone_expr ();
}
// Overloaded assignment operator to clone
ExprStmt &operator= (ExprStmt const &other)
{
Stmt::operator= (other);
// guard to prevent null dereference (only required if error state)
if (other.expr != nullptr)
expr = other.expr->clone_expr ();
else
expr = nullptr;
locus = other.locus;
semicolon_followed = other.semicolon_followed;
return *this;
}
// move constructors
ExprStmt (ExprStmt &&other) = default;
ExprStmt &operator= (ExprStmt &&other) = default;
void accept_vis (ASTVisitor &vis) override;
// Invalid if expr is null, so base stripping on that.
void mark_for_strip () override { expr = nullptr; }
bool is_marked_for_strip () const override { return expr == nullptr; }
// TODO: is this better? Or is a "vis_block" better?
std::unique_ptr &get_expr ()
{
rust_assert (expr != nullptr);
return expr;
}
bool is_semicolon_followed () const { return semicolon_followed; }
protected:
/* Use covariance to implement clone function as returning this object rather
* than base */
ExprStmt *clone_stmt_impl () const override { return new ExprStmt (*this); }
};
} // namespace AST
} // namespace Rust
#endif