Hacktoberfest 2026: le issue che i maintainer hanno segnato per ottobre, aperte e adatte ai principianti. Sfoglia le issue Hacktoberfest

Inferring during transpilation

Aperta
  • Qualcosa non va?
#1,069 0 commenti 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 3 giorni

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
4/5
Tempo stimato
3-5 giorni
Idoneità per principianti
25/100
Tipo di issue
Funzionalità
Chiarezza
Abbastanza chiara
Stato di attività
Ferma
Stack tecnologico
cpp, php
Ambito
compilers

Direzione di ricerca

Start with the provided main.php reproducer and run the shown kphp compilation command. Investigate constant-condition handling and type inference for the ternary involving KPHP_VERSION, then verify that the single-line assignment compiles while preserving the KPHP branch and PHP branch behavior.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

If I do someting like:

EmulatedEnumInt.php:

<?php
class EmulatedEnumInt {

 protected int $value;

 protected function __construct(int $value) {

  $this->value = $value;
 }

 public function __toString() : string {
  return (string) $this->value;
 }
}

CfgType.php:

<?php
#ifndef KPHP
enum CfgType : int {
case STRING = 1;
case INT = 2;
case BOOL = 3;
case ARRAY  = 4;
}
if (false) {
 #endif
 final class CfgType extends EmulatedEnumInt
 {
  const STRING = 1;
  const INT = 2;
  const BOOL = 3;
  const ARRAY  = 4;

  // GENERATED
  public static function STRING() : static {
   return new static(1);
  }

  public static function INT() : static {
   return new static(2);
  }

  public static function BOOL() : static {
   return new static(3);
  }

  public static function ARRAY() : static {
   return new static(4);
  }

  private static $fromMap = [
   1       =>      'STRING',
   2       =>      'INT',
   3       =>      'BOOL',
   4       =>      'ARRAY',
  ];

  public static function tryFrom(string|int $value) : static {
   if (isset(self::$fromMap[$value])) return new static(self::$fromMap[$value]);
   throw new \Exception("No such enum value:".$value);
  }
 }
 #ifndef KPHP
}
#endif

code.php:

<?php
include_once('CfgType.php');

#ifndef KPHP
/**
 * Get a configuration value (PHP VERSION)
 *
 * (Assumes Config object is already stored in Memcache (in KEY: '___PROJECT_SHORT____CONFIG') )
 *
 * @param string $settingName
 * @param CfgType $type
 * @param int $ttl
 *
 * @return ?int|?string|boolean|array
 */
function cfg(string $settingName, CfgType $type = CfgType::STRING, int $ttl = 86400) {

 switch($type) {

 case CfgType::STRING:
  $value = (time() % 2 === 0) ? NULL : (string)$settingName;
  return $value;

 case CfgType::INT:
  $value = (time() % 2 === 0) ? NULL : (int)80;
  return $value;

 case CfgType::BOOL:
  $value = (time() % 2 === 0) ? NULL : (bool) $settingName;
  return $value;

 case CfgType::ARRAY:
  $value = (time() % 2 === 0) ? NULL : ['foo', 'bar'];
  return $value;
 }
}

if (false) {
 #endif
 /**
  * Get a configuration value (KPHP VERSION)
  *
  * (Assumes Config object is already stored in Memcache (in KEY: '___PROJECT_SHORT____CONFIG') )
  *
  * @param string $settingName
  * @param CfgType $type
  * @param int $ttl
  *
  * @return ?int|?string|boolean|array
  */
 function cfg(string $settingName, CfgType $type, int $ttl = 86400) {

  $value = (string) $type;

  switch($value) {

  case (string)CfgType::STRING():
   $value = (time() % 2 === 0) ? NULL : (string)$settingName;
   return $value;

  case (string)CfgType::INT():
   $value = (time() % 2 === 0) ? NULL : (int)80;
   return $value;

  case (string)CfgType::BOOL():
   $value = (time() % 2 === 0) ? NULL : (bool)$settingName;
   return (bool) $settingName;

  case (string)CfgType::ARRAY():
   $value = (time() % 2 === 0) ? NULL : (array) ['foo', 'bar'];
   return $value;

  default:
   return (string) $settingName.'_default';
  }
 }

 #ifndef KPHP
}
#endif

main.php:

<?php
#ifndef KPHP // PHP
define('KPHP_VERSION', 0);
if (false)
#endif // KPHP
define('KPHP_VERSION', 1);

include('EmulatedEnumInt.php');
include('CfgType.php');
include('code.php');
 
$user = (KPHP_VERSION) ? cfg('USER', CfgType::STRING()) : cfg('USER', CfgType::STRING);

echo "User=".$user.PHP_EOL;

to cater for the fact that enums are not supported in KPHP (the code base I am trying to convert uses many enums), I would expect the transpiler to be able to deduce that the above statement can be re-written as:

$user = cfg('USER', CfgType::STRING());

since KPHP_VERSION is defined to be 1 when compiling with KPHP (and the else part of the ternary will only be taken when running in a PHP context)

However, if I compile like this:

# kphp main.php --mode server --include-dir $(pwd) -o ./server

I get this error:

Compilation error at stage: Calc actual calls, gen by type-inferer.cpp:53
 main.php:14  in global scope
   $user = (KPHP_VERSION) ? cfg('USER', CfgType::STRING()) : cfg('USER', CfgType::STRING);

pass int to argument $type of cfg
but it's declared as @param CfgType

 main.php:14  in global scope
   $user = (KPHP_VERSION) ? cfg('USER', CfgType::STRING()) : cfg('USER', CfgType::STRING);
   1 is int

apparently because it takes the else part into account ?

I would like to be able to do assignments like ($user = ) on a single line.
However, I am aware that the $user = ... line can be replaced by:

#ifndef KPHP // PHP
$user = cfg('USER', CfgType::STRING);
if (FALSE) { // KPHP
#endif
$user = cfg('USER', CfgType::STRING());
#ifndef KPHP // PHP
}
#endif 

but that syntax is rather cumbersome ...

So can't the transpiler be improved in this regard ?
Lingua principale
C++
Stelle
1.5k
Fork
116
Merge medio
3g 23h
PR unite (30g)
8

Preparare l'ambiente

  • Include un Dockerfile o un file Docker Compose
  • Nessun modello di pull request
  • Nessuna guida per i contributori

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di VKCOM/kphp

Tutte le issue di VKCOM/kphp

Issue simili

Altre issue su C++

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.