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elna/source/Transpiler.elna

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module;
from FIO import WriteNBytes, WriteLine, WriteChar, WriteString;
from SYSTEM import ADR, TSIZE;
from NumberIO import IntToStr;
from Common import Identifier, PIdentifier, ShortString;
from Parser import AstTypeExpressionKind, AstExpressionKind, AstLiteralKind, AstUnaryOperator, AstBinaryOperator,
PAstModule, PPAstExpression, PAstExpression, PAstLiteral, PPAstProcedureDeclaration,
PAstConstantDeclaration, PPAstConstantDeclaration, PPAstStatement, PAstStatement, AstStatementKind,
AstTypedDeclaration, PAstTypedDeclaration, PPAstTypedDeclaration, AstCompoundStatement, PAstProcedureDeclaration,
PAstVariableDeclaration, PPAstVariableDeclaration, PAstImportStatement, PPAstImportStatement,
PAstTypeExpression, PPAstTypeExpression, AstFieldDeclaration, PAstFieldDeclaration;
proc indent(context: PTranspilerContext);
var
count: CARDINAL;
begin
count := 0;
while count < context^.indentation do
WriteString(context^.output, ' ');
INC(count)
end
end;
(* Write a semicolon followed by a newline. *)
proc write_semicolon(output: File);
begin
WriteChar(output, ';');
WriteLine(output)
end;
proc transpile_import_statement(context: PTranspilerContext, import_statement: PAstImportStatement);
var
written_bytes: CARDINAL;
current_symbol: PIdentifier;
begin
WriteString(context^.output, 'FROM ');
written_bytes := WriteNBytes(context^.output, ORD(import_statement^.package[1]), ADR(import_statement^.package[2]));
WriteString(context^.output, ' IMPORT ');
current_symbol := import_statement^.symbols;
written_bytes := WriteNBytes(context^.output, ORD(current_symbol^[1]), ADR(current_symbol^[2]));
INC(current_symbol, TSIZE(Identifier));
while ORD(current_symbol^[1]) <> 0 do
WriteString(context^.output, ', ');
written_bytes := WriteNBytes(context^.output, ORD(current_symbol^[1]), ADR(current_symbol^[2]));
INC(current_symbol, TSIZE(Identifier))
end;
write_semicolon(context^.output)
end;
proc transpile_import_part(context: PTranspilerContext, imports: PPAstImportStatement);
var
import_statement: PAstImportStatement;
begin
while imports^ <> nil do
transpile_import_statement(context, imports^);
INC(imports, TSIZE(PAstImportStatement))
end;
WriteLine(context^.output)
end;
proc transpile_constant_declaration(context: PTranspilerContext, declaration: PAstConstantDeclaration);
var
buffer: [20]CHAR;
written_bytes: CARDINAL;
begin
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(declaration^.constant_name[1]), ADR(declaration^.constant_name[2]));
WriteString(context^.output, ' = ');
IntToStr(declaration^.constant_value, 0, buffer);
WriteString(context^.output, buffer);
write_semicolon(context^.output)
end;
proc transpile_constant_part(context: PTranspilerContext, declarations: PPAstConstantDeclaration, extra_newline: BOOLEAN);
var
current_declaration: PPAstConstantDeclaration;
begin
if declarations^ <> nil then
WriteString(context^.output, 'CONST');
WriteLine(context^.output);
current_declaration := declarations;
while current_declaration^ <> nil do
transpile_constant_declaration(context, current_declaration^);
INC(current_declaration, TSIZE(PAstConstantDeclaration))
end;
if extra_newline then
WriteLine(context^.output)
end
end
end;
proc transpile_module(context: PTranspilerContext, result: PAstModule);
begin
if result^.main = false then
WriteString(context^.output, 'IMPLEMENTATION ')
end;
WriteString(context^.output, 'MODULE ');
(* Write the module name and end the line with a semicolon and newline. *)
transpile_module_name(context);
write_semicolon(context^.output);
WriteLine(context^.output);
(* Write the module body. *)
transpile_import_part(context, result^.imports);
transpile_constant_part(context, result^.constants, true);
transpile_type_part(context, result^.types);
transpile_variable_part(context, result^.variables, true);
transpile_procedure_part(context, result^.procedures);
transpile_statement_part(context, result^.statements);
WriteString(context^.output, 'END ');
transpile_module_name(context);
WriteChar(context^.output, '.');
WriteLine(context^.output)
end;
proc transpile_type_fields(context: PTranspilerContext, fields: PAstFieldDeclaration);
var
written_bytes: CARDINAL;
current_field: PAstFieldDeclaration;
begin
current_field := fields;
while ORD(current_field^.field_name[1]) <> 0 do
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(current_field^.field_name[1]), ADR(current_field^.field_name[2]));
WriteString(context^.output, ': ');
transpile_type_expression(context, current_field^.field_type);
INC(current_field , TSIZE(AstFieldDeclaration));
if ORD(current_field^.field_name[1]) <> 0 then
WriteChar(context^.output, ';')
end;
WriteLine(context^.output)
end
end;
proc transpile_record_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
begin
WriteString(context^.output, 'RECORD');
WriteLine(context^.output);
transpile_type_fields(context, type_expression^.fields);
WriteString(context^.output, ' END')
end;
proc transpile_pointer_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
begin
WriteString(context^.output, 'POINTER TO ');
transpile_type_expression(context, type_expression^.target)
end;
proc transpile_array_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
var
buffer: [20]CHAR;
begin
WriteString(context^.output, 'ARRAY');
if type_expression^.length <> 0 then
WriteString(context^.output, '[1..');
IntToStr(type_expression^.length, 0, buffer);
WriteString(context^.output, buffer);
WriteChar(context^.output, ']')
end;
WriteString(context^.output, ' OF ');
transpile_type_expression(context, type_expression^.base)
end;
proc transpile_enumeration_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
var
current_case: PIdentifier;
written_bytes: CARDINAL;
begin
current_case := type_expression^.cases;
WriteString(context^.output, '(');
WriteLine(context^.output);
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(current_case^[1]), ADR(current_case^[2]));
INC(current_case, TSIZE(Identifier));
while ORD(current_case^[1]) <> 0 do
WriteChar(context^.output, ',');
WriteLine(context^.output);
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(current_case^[1]), ADR(current_case^[2]));
INC(current_case, TSIZE(Identifier))
end;
WriteLine(context^.output);
WriteString(context^.output, ' )')
end;
proc transpile_named_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
var
written_bytes: CARDINAL;
begin
written_bytes := WriteNBytes(context^.output, ORD(type_expression^.name[1]), ADR(type_expression^.name[2]))
end;
proc transpile_procedure_type(context: PTranspilerContext, type_expression: PAstTypeExpression);
var
result: PAstTypeExpression;
current_parameter: PPAstTypeExpression;
parameter_count: CARDINAL;
begin
WriteString(context^.output, 'PROCEDURE(');
current_parameter := type_expression^.parameters;
while current_parameter^ <> nil do
transpile_type_expression(context, current_parameter^);
INC(current_parameter, TSIZE(PAstTypeExpression));
if current_parameter^ <> nil then
WriteString(context^.output, ', ')
end
end;
WriteChar(context^.output, ')')
end;
proc transpile_type_expression(context: PTranspilerContext, type_expression: PAstTypeExpression);
begin
if type_expression^.kind = astTypeExpressionKindRecord then
transpile_record_type(context, type_expression)
end;
if type_expression^.kind = astTypeExpressionKindEnumeration then
transpile_enumeration_type(context, type_expression)
end;
if type_expression^.kind = astTypeExpressionKindArray then
transpile_array_type(context, type_expression)
end;
if type_expression^.kind = astTypeExpressionKindPointer then
transpile_pointer_type(context, type_expression)
end;
if type_expression^.kind = astTypeExpressionKindProcedure then
transpile_procedure_type(context, type_expression)
end;
if type_expression^.kind = astTypeExpressionKindNamed then
transpile_named_type(context, type_expression)
end
end;
proc transpile_type_declaration(context: PTranspilerContext, declaration: PAstTypedDeclaration);
var
written_bytes: CARDINAL;
begin
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(declaration^.identifier[1]), ADR(declaration^.identifier[2]));
WriteString(context^.output, ' = ');
transpile_type_expression(context, declaration^.type_expression);
write_semicolon(context^.output)
end;
proc transpile_type_part(context: PTranspilerContext, declarations: PPAstTypedDeclaration);
var
current_declaration: PPAstTypedDeclaration;
begin
if declarations^ <> nil then
WriteString(context^.output, 'TYPE');
WriteLine(context^.output);
current_declaration := declarations;
while current_declaration^ <> nil do
transpile_type_declaration(context, current_declaration^);
INC(current_declaration, TSIZE(PAstTypedDeclaration))
end;
WriteLine(context^.output)
end
end;
proc transpile_variable_declaration(context: PTranspilerContext, declaration: PAstVariableDeclaration);
var
written_bytes: CARDINAL;
begin
WriteString(context^.output, ' ');
written_bytes := WriteNBytes(context^.output, ORD(declaration^.variable_name[1]), ADR(declaration^.variable_name[2]));
WriteString(context^.output, ': ');
transpile_type_expression(context, declaration^.variable_type);
write_semicolon(context^.output)
end;
proc transpile_variable_part(context: PTranspilerContext, declarations: PPAstVariableDeclaration, extra_newline: BOOLEAN);
var
current_declaration: PPAstVariableDeclaration;
begin
if declarations^ <> nil then
WriteString(context^.output, 'VAR');
WriteLine(context^.output);
current_declaration := declarations;
while current_declaration^ <> nil do
transpile_variable_declaration(context, current_declaration^);
INC(current_declaration, TSIZE(PAstVariableDeclaration))
end;
if extra_newline then
WriteLine(context^.output)
end
end
end;
proc transpile_procedure_heading(context: PTranspilerContext, declaration: PAstProcedureDeclaration);
var
written_bytes: CARDINAL;
parameter_index: CARDINAL;
current_parameter: PAstTypedDeclaration;
begin
WriteString(context^.output, 'PROCEDURE ');
written_bytes := WriteNBytes(context^.output, ORD(declaration^.name[1]), ADR(declaration^.name[2]));
WriteChar(context^.output, '(');
parameter_index := 0;
current_parameter := declaration^.parameters;
while parameter_index < declaration^.parameter_count do
written_bytes := WriteNBytes(context^.output, ORD(current_parameter^.identifier[1]), ADR(current_parameter^.identifier[2]));
WriteString(context^.output, ': ');
transpile_type_expression(context, current_parameter^.type_expression);
INC(parameter_index);
INC(current_parameter, TSIZE(AstTypedDeclaration));
if parameter_index <> declaration^.parameter_count then
WriteString(context^.output, '; ')
end
end;
WriteString(context^.output, ')');
(* Check for the return type and write it. *)
if declaration^.return_type <> nil then
WriteString(context^.output, ': ');
transpile_type_expression(context, declaration^.return_type)
end;
write_semicolon(context^.output)
end;
proc transpile_unary_operator(context: PTranspilerContext, operator: AstUnaryOperator);
begin
if operator = astUnaryOperatorMinus then
WriteChar(context^.output, '-')
end;
if operator = astUnaryOperatorNot then
WriteChar(context^.output, '~')
end
end;
proc transpile_binary_operator(context: PTranspilerContext, operator: AstBinaryOperator);
begin
if operator = astBinaryOperatorSum then
WriteChar(context^.output, '+')
end;
if operator = astBinaryOperatorSubtraction then
WriteChar(context^.output, '-')
end;
if operator = astBinaryOperatorMultiplication then
WriteChar(context^.output, '*')
end;
if operator = astBinaryOperatorEquals then
WriteChar(context^.output, '=')
end;
if operator = astBinaryOperatorNotEquals then
WriteChar(context^.output, '#')
end;
if operator = astBinaryOperatorLess then
WriteChar(context^.output, '<')
end;
if operator = astBinaryOperatorGreater then
WriteChar(context^.output, '>')
end;
if operator = astBinaryOperatorLessEqual then
WriteString(context^.output, '<=')
end;
if operator = astBinaryOperatorGreaterEqual then
WriteString(context^.output, '>=')
end;
if operator = astBinaryOperatorDisjunction then
WriteString(context^.output, 'OR')
end;
if operator = astBinaryOperatorConjunction then
WriteString(context^.output, 'AND')
end
end;
proc transpile_expression(context: PTranspilerContext, expression: PAstExpression);
var
literal: PAstLiteral;
buffer: [20]CHAR;
written_bytes: CARDINAL;
argument_index: CARDINAL;
current_argument: PPAstExpression;
begin
if expression^.kind = astExpressionKindLiteral then
literal := expression^.literal;
if literal^.kind = astLiteralKindInteger then
IntToStr(literal^.integer, 0, buffer);
WriteString(context^.output, buffer)
end;
if literal^.kind = astLiteralKindString then
WriteString(context^.output, literal^.string)
end;
if literal^.kind = astLiteralKindNull then
WriteString(context^.output, 'NIL')
end;
if (literal^.kind = astLiteralKindBoolean) & literal^.boolean then
WriteString(context^.output, 'TRUE')
end;
if (literal^.kind = astLiteralKindBoolean) & (literal^.boolean = false) then
WriteString(context^.output, 'FALSE')
end
end;
if expression^.kind = astExpressionKindIdentifier then
written_bytes := WriteNBytes(context^.output, ORD(expression^.identifier[1]), ADR(expression^.identifier[2]))
end;
if expression^.kind = astExpressionKindDereference then
transpile_expression(context, expression^.reference);
WriteChar(context^.output, '^')
end;
if expression^.kind = astExpressionKindArrayAccess then
transpile_expression(context, expression^.array);
WriteChar(context^.output, '[');
transpile_expression(context, expression^.index);
WriteChar(context^.output, ']')
end;
if expression^.kind = astExpressionKindFieldAccess then
transpile_expression(context, expression^.aggregate);
WriteChar(context^.output, '.');
written_bytes := WriteNBytes(context^.output, ORD(expression^.field[1]), ADR(expression^.field[2]))
end;
if expression^.kind = astExpressionKindUnary then
transpile_unary_operator(context, expression^.unary_operator);
transpile_expression(context, expression^.unary_operand)
end;
if expression^.kind = astExpressionKindBinary then
WriteChar(context^.output, '(');
transpile_expression(context, expression^.lhs);
WriteChar(context^.output, ' ');
transpile_binary_operator(context, expression^.binary_operator);
WriteChar(context^.output, ' ');
transpile_expression(context, expression^.rhs);
WriteChar(context^.output, ')')
end;
if expression^.kind = astExpressionKindCall then
transpile_expression(context, expression^.callable);
WriteChar(context^.output, '(');
current_argument := expression^.arguments;
if expression^.argument_count > 0 then
transpile_expression(context, current_argument^);
argument_index := 1;
INC(current_argument, TSIZE(PAstExpression));
while argument_index < expression^.argument_count do
WriteString(context^.output, ', ');
transpile_expression(context, current_argument^);
INC(current_argument, TSIZE(PAstExpression));
INC(argument_index)
end
end;
WriteChar(context^.output, ')')
end
end;
proc transpile_if_statement(context: PTranspilerContext, statement: PAstStatement);
begin
WriteString(context^.output, 'IF ');
transpile_expression(context, statement^.if_condition);
WriteString(context^.output, ' THEN');
WriteLine(context^.output);
INC(context^.indentation);
transpile_compound_statement(context, statement^.if_branch);
DEC(context^.indentation);
indent(context);
WriteString(context^.output, 'END')
end;
proc transpile_while_statement(context: PTranspilerContext, statement: PAstStatement);
begin
WriteString(context^.output, 'WHILE ');
transpile_expression(context, statement^.while_condition);
WriteString(context^.output, ' DO');
WriteLine(context^.output);
INC(context^.indentation);
transpile_compound_statement(context, statement^.while_body);
DEC(context^.indentation);
indent(context);
WriteString(context^.output, 'END')
end;
proc transpile_assignment_statement(context: PTranspilerContext, statement: PAstStatement);
begin
transpile_expression(context, statement^.assignee);
WriteString(context^.output, ' := ');
transpile_expression(context, statement^.assignment)
end;
proc transpile_return_statement(context: PTranspilerContext, statement: PAstStatement);
begin
WriteString(context^.output, 'RETURN ');
transpile_expression(context, statement^.returned)
end;
proc transpile_compound_statement(context: PTranspilerContext, statement: AstCompoundStatement);
var
current_statement: PPAstStatement;
index: CARDINAL;
begin
index := 0;
current_statement := statement.statements;
while index < statement.count do
transpile_statement(context, current_statement^);
INC(current_statement, TSIZE(PAstStatement));
INC(index);
if index <> statement.count then
WriteChar(context^.output, ';')
end;
WriteLine(context^.output)
end
end;
proc transpile_statement(context: PTranspilerContext, statement: PAstStatement);
begin
indent(context);
if statement^.kind = astStatementKindIf then
transpile_if_statement(context, statement)
end;
if statement^.kind = astStatementKindWhile then
transpile_while_statement(context, statement)
end;
if statement^.kind = astStatementKindReturn then
transpile_return_statement(context, statement)
end;
if statement^.kind = astStatementKindAssignment then
transpile_assignment_statement(context, statement)
end;
if statement^.kind = astStatementKindCall then
transpile_expression(context, statement^.call)
end
end;
proc transpile_statement_part(context: PTranspilerContext, compound: AstCompoundStatement);
begin
if compound.count > 0 then
WriteString(context^.output, 'BEGIN');
WriteLine(context^.output);
INC(context^.indentation);
transpile_compound_statement(context, compound);
DEC(context^.indentation)
end
end;
proc transpile_procedure_declaration(context: PTranspilerContext, declaration: PAstProcedureDeclaration);
var
written_bytes: CARDINAL;
begin
transpile_procedure_heading(context, declaration);
transpile_constant_part(context, declaration^.constants, false);
transpile_variable_part(context, declaration^.variables, false);
transpile_statement_part(context, declaration^.statements);
WriteString(context^.output, 'END ');
written_bytes := WriteNBytes(context^.output, ORD(declaration^.name[1]), ADR(declaration^.name[2]));
write_semicolon(context^.output)
end;
proc transpile_procedure_part(context: PTranspilerContext, declaration: PPAstProcedureDeclaration);
begin
while declaration^ <> nil do
transpile_procedure_declaration(context, declaration^);
WriteLine(context^.output);
INC(declaration, TSIZE(PAstProcedureDeclaration))
end
end;
proc transpile_module_name(context: PTranspilerContext);
var
counter: CARDINAL;
last_slash: CARDINAL;
begin
counter := 1;
last_slash := 0;
while (context^.input_name[counter] <> '.') & (ORD(context^.input_name[counter]) <> 0) do
if context^.input_name[counter] = '/' then
last_slash := counter
end;
INC(counter)
end;
if last_slash = 0 then
counter := 1
end;
if last_slash <> 0 then
counter := last_slash + 1
end;
while (context^.input_name[counter] <> '.') & (ORD(context^.input_name[counter]) <> 0) do
WriteChar(context^.output, context^.input_name[counter]);
INC(counter)
end
end;
proc transpile(ast_module: PAstModule, output: File, definition: File, input_name: ShortString);
var
context: TranspilerContext;
begin
context.input_name := input_name;
context.output := output;
context.definition := definition;
context.indentation := 0;
transpile_module(ADR(context), ast_module)
end;
end.