Implement simple if conditions

This commit is contained in:
2024-03-17 01:00:44 +01:00
parent 8240443cd1
commit 17b0650f77
13 changed files with 592 additions and 33 deletions

View File

@ -1,6 +1,8 @@
#pragma once
#include <charconv>
#include <cstdint>
#include <algorithm>
#include "elna/source/parser.hpp"
namespace elna::riscv
@ -144,9 +146,11 @@ namespace elna::riscv
instruction(base_opcode opcode);
instruction& i(x_register rd, funct3_t funct3, x_register rs1, std::uint32_t immediate);
instruction& s(std::uint32_t imm1, funct3_t funct3, x_register rs1, x_register rs2);
instruction& s(std::uint32_t imm, funct3_t funct3, x_register rs1, x_register rs2);
instruction& b(std::uint32_t imm, funct3_t funct3, x_register rs1, x_register rs2);
instruction& r(x_register rd, funct3_t funct3, x_register rs1, x_register rs2, funct7_t funct7 = funct7_t::none);
instruction& u(x_register rd, std::uint32_t imm);
instruction& j(x_register rd, std::uint32_t imm);
const std::byte *cbegin() const;
const std::byte *cend() const;
@ -155,6 +159,160 @@ namespace elna::riscv
std::uint32_t representation{ 0 };
};
/**
* Assigns sequentially numbered labels to text strings.
*/
template<char... prefix>
struct read_only_table
{
private:
constexpr static const char get_prefix[] = { prefix... };
constexpr static const std::size_t prefix_length = sizeof(get_prefix) / sizeof(char);
public:
/**
* An iterator over label and string pairs.
*/
struct const_iterator
{
using iterator_category = std::forward_iterator_tag;
using difference_type = ptrdiff_t;
using value_type = std::pair<std::string, std::string_view>;
using pointer = const value_type *;
using reference = const value_type&;
reference operator*() const noexcept
{
return payload;
}
pointer operator->() const noexcept
{
return &payload;
}
const_iterator& operator++()
{
++index;
++iterator;
this->payload = std::pair<const std::string, std::string_view>(label(), *iterator);
return *this;
}
const_iterator& operator++(int)
{
auto tmp = *this;
++(*this);
return *this;
}
bool operator==(const const_iterator& that) const
{
return this->index == that.index;
}
bool operator!=(const const_iterator& that) const
{
return !(*this == that);
}
private:
std::vector<std::string>::const_iterator iterator;
std::size_t index;
value_type payload;
const_iterator(std::size_t index, std::vector<std::string>::const_iterator iterator)
: iterator(iterator), index(index), payload({ label(), *iterator })
{
}
const_iterator(std::size_t index, std::vector<std::string>::const_iterator iterator,
std::string_view value)
: iterator(iterator), index(index), payload({ get_prefix, value })
{
}
std::string label() const
{
return get_prefix + std::to_string(this->index);
}
friend read_only_table;
};
const_iterator begin()
{
if (payload.empty())
{
return end();
}
else
{
return read_only_table::const_iterator(0, payload.cbegin());
}
}
const_iterator end() const
{
return read_only_table::const_iterator(size(), payload.cend(), "");
}
std::size_t size() const
{
return payload.size();
}
/**
* Looks up \a needle in the string storage and returns a label for it
* or create a new one.
*
* \param needle A string to search for.
* \return Label name.
*/
const_iterator label(std::string_view needle)
{
auto format_string = std::find(this->payload.cbegin(), this->payload.cend(), needle);
if (format_string == this->payload.cend())
{
format_string = this->payload.emplace(format_string, needle);
}
auto read_only_index = std::distance(this->payload.cbegin(), format_string);
return read_only_table::const_iterator(read_only_index, format_string);
}
/**
* Searches the content by label and returns its index or -1 when the
* label does not exist.
*
* \param needle Label name.
* \return Data index.
*/
std::ptrdiff_t lookup(std::string_view needle)
{
if (needle.size() <= prefix_length)
{
return -1;
}
auto needle_middle = needle.cbegin() + prefix_length;
auto needle_prefix = std::string_view(needle.cbegin(), prefix_length);
std::size_t counter;
auto [position, char_error] = std::from_chars(needle_middle, needle.cend(), counter);
if (char_error != std::errc{} || position != needle.cend()
|| needle_prefix != get_prefix || counter >= size())
{
return -1;
}
return counter;
}
private:
std::vector<std::string> payload;
};
class visitor final : public source::parser_visitor
{
public:
@ -163,15 +321,20 @@ namespace elna::riscv
std::uint32_t variable_counter = 1;
std::vector<reference> references;
std::shared_ptr<source::symbol_table> table;
read_only_table<'.', 'C', 'L'> read_only;
virtual void visit(source::declaration *declaration) override;
virtual void visit(source::definition *definition) override;
virtual void visit(source::bang_statement *statement) override;
virtual void visit(source::question_mark_statement *statement) override;
virtual void visit(source::compound_statement *statement) override;
virtual void visit(source::assign_statement *statement) override;
virtual void visit(source::if_statement *statement) override;
virtual void visit(source::while_statement *statement) override;
virtual void visit(source::block *block) override;
virtual void visit(source::variable_expression *variable) override;
virtual void visit(source::integer_literal *number) override;
virtual void visit(source::binary_expression *expression) override;
virtual void visit(source::integer_literal *number) override;
virtual void visit(source::boolean_literal *number) override;
};
}

View File

@ -53,6 +53,7 @@ namespace elna::source
enum class type : std::uint16_t
{
number,
boolean,
term_operator,
let,
identifier,
@ -68,7 +69,13 @@ namespace elna::source
eof,
begin,
end,
assignment
assignment,
colon,
question_mark,
when,
then,
_while,
_do
};
/**
@ -107,6 +114,7 @@ namespace elna::source
elna::source::position m_position;
bool has_identifier() const noexcept;
bool is_numeric() const noexcept;
};
class unexpected_character final : public error

View File

@ -17,24 +17,32 @@ namespace elna::source
class declaration;
class definition;
class bang_statement;
class question_mark_statement;
class compound_statement;
class assign_statement;
class if_statement;
class while_statement;
class block;
class binary_expression;
class variable_expression;
class integer_literal;
class boolean_literal;
struct parser_visitor
{
virtual void visit(declaration *) = 0;
virtual void visit(definition *) = 0;
virtual void visit(bang_statement *) = 0;
virtual void visit(question_mark_statement *) = 0;
virtual void visit(compound_statement *) = 0;
virtual void visit(assign_statement *) = 0;
virtual void visit(if_statement *) = 0;
virtual void visit(while_statement *) = 0;
virtual void visit(block *) = 0;
virtual void visit(binary_expression *) = 0;
virtual void visit(variable_expression *) = 0;
virtual void visit(integer_literal *) = 0;
virtual void visit(boolean_literal *) = 0;
};
struct empty_visitor : parser_visitor
@ -42,12 +50,16 @@ namespace elna::source
virtual void visit(declaration *declaration) override;
virtual void visit(definition *definition) override;
virtual void visit(bang_statement *statement) override;
virtual void visit(question_mark_statement *statement) override;
virtual void visit(compound_statement *statement) override;
virtual void visit(assign_statement *statement) override;
virtual void visit(if_statement *) override;
virtual void visit(while_statement *) override;
virtual void visit(block *block) override;
virtual void visit(binary_expression *expression) override;
virtual void visit(variable_expression *variable) override;
virtual void visit(integer_literal *number) override;
virtual void visit(boolean_literal *boolean) override;
};
/**
@ -67,6 +79,10 @@ namespace elna::source
{
};
class condition : public node
{
};
/**
* Variable declaration.
*/
@ -108,6 +124,17 @@ namespace elna::source
expression& body();
};
class question_mark_statement : public statement
{
std::unique_ptr<condition> m_body;
public:
question_mark_statement(std::unique_ptr<condition>&& body);
virtual void accept(parser_visitor *visitor) override;
condition& body();
};
class compound_statement : public statement
{
std::vector<std::unique_ptr<statement>> m_statements;
@ -133,6 +160,32 @@ namespace elna::source
expression& rvalue();
};
class if_statement : public statement
{
std::unique_ptr<condition> m_prerequisite;
std::unique_ptr<statement> m_body;
public:
if_statement(std::unique_ptr<condition>&& prerequisite, std::unique_ptr<statement>&& body);
virtual void accept(parser_visitor *visitor) override;
condition& prerequisite();
statement& body();
};
class while_statement : public statement
{
std::unique_ptr<condition> m_prerequisite;
std::unique_ptr<statement> m_body;
public:
while_statement(std::unique_ptr<condition>&& prerequisite, std::unique_ptr<statement>&& body);
virtual void accept(parser_visitor *visitor) override;
condition& prerequisite();
statement& body();
};
/**
* Block.
*/
@ -166,6 +219,17 @@ namespace elna::source
std::int32_t number() const noexcept;
};
class boolean_literal : public condition
{
bool m_boolean;
public:
boolean_literal(const bool value);
virtual void accept(parser_visitor *visitor) override;
bool boolean() const noexcept;
};
class variable_expression : public expression
{
std::string m_name;
@ -198,12 +262,16 @@ namespace elna::source
std::unique_ptr<expression> parse_factor();
std::unique_ptr<expression> parse_term();
std::unique_ptr<expression> parse_expression();
std::unique_ptr<condition> parse_condition();
std::unique_ptr<definition> parse_definition();
std::unique_ptr<declaration> parse_declaration();
std::unique_ptr<statement> parse_statement();
std::unique_ptr<bang_statement> parse_bang_statement();
std::unique_ptr<question_mark_statement> parse_question_mark_statement();
std::unique_ptr<compound_statement> parse_compound_statement();
std::unique_ptr<assign_statement> parse_assign_statement();
std::unique_ptr<if_statement> parse_if_statement();
std::unique_ptr<while_statement> parse_while_statement();
std::vector<std::unique_ptr<definition>> parse_definitions();
std::vector<std::unique_ptr<declaration>> parse_declarations();
std::unique_ptr<block> parse_block();