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Cast expressions

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This commit is contained in:
Eugen Wissner
2025-01-28 11:21:02 +01:00
parent 18d8ded239
commit be1a56a557
9 changed files with 183 additions and 136 deletions
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91
example.elna
View File

@@ -1,7 +1,7 @@
type
TokenValue = union
intValue: Int;
stringValue: String
stringValue: pointer to Char
end,
Token = record
kind: Int;
@@ -12,7 +12,9 @@ type
end;
const
SEEK_SET = 0, SEEK_CUR = 1, SEEK_END = 2;
SEEK_SET = 0, SEEK_CUR = 1, SEEK_END = 2,
POINTER_SIZE = 8, TOKEN_SIZE = 16,
TOKEN_IDENTIFIER = 1;
--
-- External procedures.
@@ -27,9 +29,13 @@ proc write(fd: Int, buf: pointer to Char, count: Int): Int; extern;
proc malloc(size: Int): pointer to Char; extern;
proc free(ptr: pointer to Char); extern;
proc calloc(nmemb: Int, size: Int): pointer to Char; extern;
proc realloc(ptr: pointer to Char, size: Int): pointer to Char; extern;
proc memset(ptr: pointer to Char, c: Int, n: Int): pointer to Char; extern;
proc strncmp(s1: pointer to Char, s2: pointer to Char, n: Word): Int; extern;
proc strncpy(dst: pointer to Char, src: pointer to Char, dsize: Word): pointer to Char; extern;
proc strncpy(dst: pointer to Char, src: pointer to Char, dsize: Word): pointer to Char; extern;
proc strlen(ptr: pointer to Char): Word; extern;
proc exit(code: Int); extern;
@@ -68,7 +74,7 @@ begin
digit := value % 10;
value := value / 10;
buffer[n] := Char(Int('0') + digit);
buffer[n] := cast(cast('0' as Int) + digit as Char);
n := n - 1
end;
while n < 10 do
@@ -82,6 +88,26 @@ begin
write_i(value)
end;
proc is_digit(c: Char): Bool;
begin
return cast(c as Int) >= cast('0' as Int) and cast(c as Int) <= cast('9' as Int)
end;
proc is_alpha(c: Char): Bool;
begin
return cast(c as Int) >= cast('A' as Int) and cast(c as Int) <= cast('z' as Int)
end;
proc is_alnum(c: Char): Bool;
begin
return is_digit(c) or is_alpha(c)
end;
proc is_space(c: Char): Bool;
begin
return c = ' ' or c = '\n'
end;
--
-- End of standard procedures.
--
@@ -130,17 +156,68 @@ begin
return input
end;
proc skip_spaces(input: pointer to Char): pointer to Char;
begin
while is_space(input^) do
input := input + 1
end;
return input
end;
proc lex_identifier(input: pointer to Char): pointer to Char;
begin
while is_alnum(input^) or input^ = '_' do
input := input + 1
end;
return input
end;
proc compile();
var
input: pointer to Char,
input_pointer: pointer to Char;
input_pointer: pointer to Char,
token_end: pointer to Char,
token_length: Int,
tokens: pointer to Token,
current_token: pointer to Token,
tokens_size: Int,
i: Int;
begin
tokens_size := 0;
tokens := cast(0 as pointer to Token);
input := read_source("example.elna");
input_pointer := input;
input_pointer := skip_spaces(input);
while input_pointer^ /= '\0' do
write(0, input_pointer, 1);
input_pointer := input_pointer + 1
if is_alpha(input_pointer^) or input_pointer^ = '_' then
token_end := lex_identifier(input_pointer + 1);
token_length := cast(token_end as Int) - cast(input_pointer as Int);
tokens := cast(realloc(tokens, tokens_size + TOKEN_SIZE) as pointer to Token);
current_token := tokens + tokens_size;
current_token^.kind := TOKEN_IDENTIFIER;
current_token^.value.stringValue := cast(calloc(token_length + 1, 1) as pointer to Char);
strncpy(current_token^.value.stringValue, input_pointer, token_length);
tokens_size := tokens_size + TOKEN_SIZE;
input_pointer := token_end
else
input_pointer := input_pointer + 1
end
end;
i := 0;
while i < tokens_size do
current_token := tokens + i;
write_s(current_token^.value.stringValue);
write_c('\n');
i := i + TOKEN_SIZE
end;
free(input)

47
gcc/elna-generic.cc
View File

@@ -20,40 +20,21 @@ namespace gcc
this->symbol_map = symbol_table;
}
void generic_visitor::visit(source::call_expression *statement)
void generic_visitor::visit(source::call_expression *expression)
{
auto symbol = this->symbol_map->lookup(statement->name());
if (statement->name() == "Int" || statement->name() == "Word" || statement->name() == "Bool"
|| statement->name() == "Float" || statement->name() == "Char")
{
if (statement->arguments().size() != 1)
{
error_at(get_location(&statement->position()),
"procedure '%s' expects 1 argument, %lu given",
statement->name().c_str(), statement->arguments().size());
return;
}
auto& argument = statement->arguments().at(0);
argument->accept(this);
tree argument_type = TREE_TYPE(this->current_expression);
this->current_expression = build1_loc(get_location(&argument->position()), CONVERT_EXPR,
symbol->payload, this->current_expression);
}
else if (symbol)
if (auto symbol = this->symbol_map->lookup(expression->name()))
{
tree return_type = TREE_TYPE(TREE_TYPE(symbol->payload));
tree fndecl_type = build_function_type(return_type, TYPE_ARG_TYPES(symbol->payload));
tree printf_fn = build1(ADDR_EXPR, build_pointer_type(fndecl_type), symbol->payload);
std::vector<tree> arguments(statement->arguments().size());
for (std::size_t i = 0; i < statement->arguments().size(); ++i)
std::vector<tree> arguments(expression->arguments().size());
for (std::size_t i = 0; i < expression->arguments().size(); ++i)
{
statement->arguments().at(i)->accept(this);
expression->arguments().at(i)->accept(this);
arguments[i] = this->current_expression;
}
tree stmt = build_call_array_loc(get_location(&statement->position()),
tree stmt = build_call_array_loc(get_location(&expression->position()),
return_type, printf_fn, arguments.size(), arguments.data());
if (return_type == void_type_node)
@@ -68,12 +49,24 @@ namespace gcc
}
else
{
error_at(get_location(&statement->position()),
error_at(get_location(&expression->position()),
"procedure '%s' not declared",
statement->name().c_str());
expression->name().c_str());
this->current_expression = error_mark_node;
}
}
void generic_visitor::visit(source::cast_expression *expression)
{
tree cast_target = build_type(expression->target());
gcc_assert(cast_target != NULL_TREE);
expression->value().accept(this);
this->current_expression = build1_loc(get_location(&expression->position()), CONVERT_EXPR,
cast_target, this->current_expression);
}
void generic_visitor::visit(source::program *program)
{
for (const auto definition : program->value_definitions)

6
gcc/elna-tree.cc
View File

@@ -28,6 +28,12 @@ namespace gcc
&& TYPE_MAIN_VARIANT(TREE_TYPE(type)) == char_type_node;
}
bool is_integral_type(tree type)
{
gcc_assert(TYPE_P(type));
return type == integer_type_node || type == unsigned_type_node;
}
tree tree_chain_base::head()
{
return first;

3
include/elna/gcc/elna-generic.h
View File

@@ -41,7 +41,8 @@ namespace gcc
void visit(source::program *program) override;
void visit(source::procedure_definition *definition) override;
void visit(source::call_expression *statement) override;
void visit(source::call_expression *expression) override;
void visit(source::cast_expression *expression) override;
void visit(source::number_literal<std::int32_t> *literal) override;
void visit(source::number_literal<std::uint32_t> *literal) override;
void visit(source::number_literal<double> *literal) override;

1
include/elna/gcc/elna-tree.h
View File

@@ -27,6 +27,7 @@ namespace gcc
void init_ttree();
bool is_pointer_type(tree type);
bool is_string_type(tree type);
bool is_integral_type(tree type);
class tree_chain_base
{

77
include/elna/source/ast.h
View File

@@ -41,6 +41,7 @@ namespace source
class procedure_definition;
class type_definition;
class call_expression;
class cast_expression;
class assign_statement;
class if_statement;
class while_statement;
@@ -74,6 +75,7 @@ namespace source
virtual void visit(procedure_definition *) = 0;
virtual void visit(type_definition *) = 0;
virtual void visit(call_expression *) = 0;
virtual void visit(cast_expression *) = 0;
virtual void visit(expression_statement *) = 0;
virtual void visit(assign_statement *) = 0;
virtual void visit(if_statement *) = 0;
@@ -109,7 +111,8 @@ namespace source
virtual void visit(constant_definition *definition) override;
virtual void visit(procedure_definition *definition) override;
virtual void visit(type_definition *definition) override;
virtual void visit(call_expression *statement) override;
virtual void visit(call_expression *expression) override;
virtual void visit(cast_expression *expression) override;
virtual void visit(expression_statement *statement) override;
virtual void visit(assign_statement *statement) override;
virtual void visit(if_statement *) override;
@@ -136,55 +139,6 @@ namespace source
virtual void visit(string_literal *) override;
};
/**
* Operand representing a subexpression in the 3 address code.
*/
struct operand
{
public:
virtual ~operand() = 0;
};
struct integer_operand final : public operand
{
std::int32_t m_value;
public:
explicit integer_operand(const std::int32_t value);
std::int32_t value() const;
};
class variable_operand final : public operand
{
std::string m_name;
public:
explicit variable_operand(const std::string& name);
const std::string& name() const;
};
struct temporary_variable final : public operand
{
std::size_t m_counter;
public:
explicit temporary_variable(const std::size_t counter);
std::size_t counter() const;
};
struct label_operand final : public operand
{
std::size_t m_counter;
public:
explicit label_operand(const std::size_t counter);
std::size_t counter() const;
};
/**
* AST node.
*/
@@ -219,9 +173,6 @@ namespace source
class expression : public node
{
public:
std::shared_ptr<operand> place;
protected:
/**
* \param position Source code position.
@@ -448,7 +399,7 @@ namespace source
};
/**
* Call statement.
* Procedure call expression.
*/
class call_expression : public expression
{
@@ -469,6 +420,24 @@ namespace source
virtual ~call_expression() override;
};
/**
* Cast expression.
*/
class cast_expression : public expression
{
type_expression *m_target;
expression *m_value;
public:
cast_expression(const struct position position, type_expression *target, expression *value);
virtual void accept(parser_visitor *visitor) override;
type_expression& target();
expression& value();
virtual ~cast_expression() override;
};
class expression_statement : public statement
{
expression *m_body;

80
source/ast.cc
View File

@@ -33,14 +33,20 @@ namespace source
definition->body().accept(this);
}
void empty_visitor::visit(call_expression *statement)
void empty_visitor::visit(call_expression *expression)
{
for (auto& argument : statement->arguments())
for (auto& argument : expression->arguments())
{
argument->accept(this);
}
}
void empty_visitor::visit(cast_expression *expression)
{
expression->target().accept(this);
expression->value().accept(this);
}
void empty_visitor::visit(expression_statement *statement)
{
statement->body().accept(this);
@@ -185,50 +191,6 @@ namespace source
{
}
operand::~operand()
{
}
integer_operand::integer_operand(const std::int32_t value)
: m_value(value)
{
}
std::int32_t integer_operand::value() const
{
return m_value;
}
variable_operand::variable_operand(const std::string& name)
: m_name(name)
{
}
const std::string& variable_operand::name() const
{
return m_name;
}
temporary_variable::temporary_variable(const std::size_t counter)
: m_counter(counter)
{
}
std::size_t temporary_variable::counter() const
{
return m_counter;
}
label_operand::label_operand(const std::size_t counter)
: m_counter(counter)
{
}
std::size_t label_operand::counter() const
{
return m_counter;
}
node::node(const struct position position)
: source_position(position)
{
@@ -766,6 +728,32 @@ namespace source
}
}
cast_expression::cast_expression(const struct position position, type_expression *target, expression *value)
: expression(position), m_target(target), m_value(value)
{
}
void cast_expression::accept(parser_visitor *visitor)
{
visitor->visit(this);
}
type_expression& cast_expression::target()
{
return *m_target;
}
expression& cast_expression::value()
{
return *m_value;
}
cast_expression::~cast_expression()
{
delete m_target;
delete m_value;
}
expression_statement::expression_statement(const struct position position, expression *body)
: statement(position), m_body(body)
{

6
source/lexer.ll
View File

@@ -106,6 +106,12 @@ not {
return {
return yy::parser::make_RETURN(this->location);
}
cast {
return yy::parser::make_CAST(this->location);
}
as {
return yy::parser::make_AS(this->location);
}
[A-Za-z_][A-Za-z0-9_]* {
return yy::parser::make_IDENTIFIER(yytext, this->location);
}

8
source/parser.yy
View File

@@ -67,7 +67,7 @@
%token CONST VAR PROCEDURE ARRAY OF TYPE RECORD POINTER TO UNION
%token BEGIN_BLOCK END_BLOCK EXTERN
%token LEFT_PAREN RIGHT_PAREN LEFT_SQUARE RIGHT_SQUARE SEMICOLON DOT COMMA
%token AND OR NOT
%token AND OR NOT CAST AS
%token GREATER_EQUAL LESS_EQUAL LESS_THAN GREATER_THAN NOT_EQUAL EQUALS
%token PLUS MINUS MULTIPLICATION DIVISION REMAINDER
%token ASSIGNMENT COLON HAT AT
@@ -97,6 +97,7 @@
%type <std::pair<std::string, elna::source::type_expression *>> field_declaration;
%type <std::vector<std::pair<std::string, elna::source::type_expression *>>> field_list;
%type <std::vector<elna::source::conditional_statements *>> elsif_statement_list;
%type <elna::source::cast_expression *> cast_expression;
%%
program:
type_part constant_part procedure_part variable_part BEGIN_BLOCK optional_statements END_BLOCK DOT
@@ -183,6 +184,10 @@ call_expression: IDENTIFIER actual_parameter_list
$$ = new elna::source::call_expression(elna::source::make_position(@1), $1);
std::swap($$->arguments(), $2);
}
cast_expression: CAST LEFT_PAREN expression AS type_expression RIGHT_PAREN
{
$$ = new elna::source::cast_expression(elna::source::make_position(@1), $5, $3);
}
while_statement: WHILE expression DO optional_statements END_BLOCK
{
auto body = new elna::source::conditional_statements($2);
@@ -247,6 +252,7 @@ literal:
pointer:
literal { $$ = $1; }
| designator_expression { $$ = $1; }
| cast_expression { $$ = $1; }
| call_expression { $$ = $1; }
| LEFT_PAREN expression RIGHT_PAREN { $$ = std::move($2); }
summand: