gen_stub: Infer constants' types from values (#19568)

Don't require `@var` with a type when the type can be inferred from a literal
value in the stub file.

Author: DanielEScherzer

Zend/zend_constants.stub.php

@@ -130,17 +130,14 @@
 /* Special constants true/false/null.  */
 
 /**
- * @var bool
  * @undocumentable
  */
 const TRUE = true;
 /**
- * @var bool
  * @undocumentable
  */
 const FALSE = false;
 /**
- * @var null
  * @undocumentable
  */
 const NULL = null;

Zend/zend_constants_arginfo.h

@@ -4874,7 +4874,32 @@ function parseConstLike(
     }
 
     if ($type === null && $phpDocType === null) {
-        throw new Exception("Missing type for constant " . $name->__toString());
+        if ($const->value instanceof Node\Scalar\Float_) {
+            $phpDocType = 'float';
+        } elseif ($const->value instanceof Node\Scalar\Int_
+            || ($const->value instanceof Expr\UnaryMinus
+                && $const->value->expr instanceof Node\Scalar\Int_
+            )
+        ) {
+            $phpDocType = 'int';
+        } elseif ($const->value instanceof Node\Scalar\String_) {
+            $phpDocType = 'string';
+        } elseif ($const->value instanceof Expr\ConstFetch
+            && $const->value->name instanceof Node\Name\FullyQualified
+            && (
+                $const->value->name->name === 'false'
+                || $const->value->name->name === 'true'
+            )
+        ) {
+            $phpDocType = 'bool';
+        } elseif ($const->value instanceof Expr\ConstFetch
+            && $const->value->name instanceof Node\Name\FullyQualified
+            && $const->value->name->name === 'null'
+        ) {
+            $phpDocType = 'null';
+        } else {
+            throw new Exception("Missing type for constant " . $name->__toString());
+        }
     }
 
     $constType = $type ? Type::fromNode($type) : null;

build/gen_stub.php

@@ -3,74 +3,62 @@
 /** @generate-class-entries */
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC3339
  */
 const DATE_ATOM = "Y-m-d\\TH:i:sP";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_COOKIE
  */
 const DATE_COOKIE = "l, d-M-Y H:i:s T";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_ISO8601
  */
 const DATE_ISO8601 = "Y-m-d\\TH:i:sO";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_ISO8601_EXPANDED
  */
 const DATE_ISO8601_EXPANDED = "X-m-d\\TH:i:sP";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC822
  */
 const DATE_RFC822 = "D, d M y H:i:s O";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC850
  */
 const DATE_RFC850 = "l, d-M-y H:i:s T";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC1036
  */
 const DATE_RFC1036 = "D, d M y H:i:s O";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC1123
  */
 const DATE_RFC1123 = "D, d M Y H:i:s O";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC7231
  */
 #[\Deprecated(since: '8.5', message: "as this format ignores the associated timezone and always uses GMT")]
 const DATE_RFC7231 = "D, d M Y H:i:s \\G\\M\\T";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC2822
  */
 const DATE_RFC2822 = "D, d M Y H:i:s O";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC3339
  */
 const DATE_RFC3339 = "Y-m-d\\TH:i:sP";
 
 /**
- * @var string
  * @cvalue DATE_FORMAT_RFC3339_EXTENDED
  */
 const DATE_RFC3339_EXTENDED = "Y-m-d\\TH:i:s.vP";

ext/date/php_date.stub.php

@@ -14,7 +14,6 @@ final class Connection
 
 namespace {
 #ifdef DBA_LMDB
-    /** @var int */
     const DBA_LMDB_USE_SUB_DIR = 0;
     /**
      * @var int

ext/date/php_date_arginfo.h

@@ -5,7 +5,6 @@
  * @undocumentable
  */
 
-/** @var int */
 const DL_TEST_CONST = 42;
 
 function dl_test_test1(): void {}

ext/dba/dba.stub.php

@@ -449,17 +449,11 @@
  * /usr/include/pngconf.h:310:2: error: #error png.h already includes setjmp.h with some additional fixup.
  * as error, use the values for now...
  */
-/** @var int */
 const PNG_NO_FILTER = 0x00;
-/** @var int */
 const PNG_FILTER_NONE = 0x08;
-/** @var int */
 const PNG_FILTER_SUB = 0x10;
-/** @var int */
 const PNG_FILTER_UP = 0x20;
-/** @var int */
 const PNG_FILTER_AVG = 0x40;
-/** @var int */
 const PNG_FILTER_PAETH = 0x80;
 /** @var int */
 const PNG_ALL_FILTERS = 0x08 | 0x10 | 0x20 | 0x40 | 0x80;