Implement mb_strstr() — multibyte strstr (ext/mbstring parity)

ext/mbstring/Module.php

@@ -53,6 +53,7 @@ public function getFunctions(): array
             new mb_stripos(),
             new mb_strrpos(),
             new mb_strrichr(),
+            new mb_strstr(),
             ...(CompilerVersion::supportsMbTrimFunctions() ? [
                 new mb_trim(),
                 new mb_ltrim(),

ext/mbstring/VmMbstring.php

@@ -542,6 +542,26 @@ public static function strpos(string $haystack, string $needle, int $offset = 0,
         return self::utf8Strpos($haystack, $needle, $offset, false, $encoding, 'mb_strpos');
     }
 
+    /**
+     * mb_strstr() — find first occurrence and return haystack from that point (php-src ext/mbstring/mbstring.c).
+     *
+     * @return string|false
+     */
+    public static function strstr(string $haystack, string $needle, bool $part = false, string $encoding = 'UTF-8')
+    {
+        self::assertSearchEncoding($encoding);
+        $pos = self::utf8Strpos($haystack, $needle, 0, false, $encoding, 'mb_strstr');
+        if (false === $pos) {
+            return false;
+        }
+        if ($part) {
+            return VmString::utf8CharSubstr($haystack, 0, $pos);
+        }
+        $charLen = VmString::utf8CharLength($haystack);
+
+        return VmString::utf8CharSubstr($haystack, $pos, $charLen - $pos);
+    }
+
     public static function substr(
         string $string,
         int $start,

ext/mbstring/mb_strstr.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler\ext\mbstring;
+
+use PHPCompiler\ext\standard\VmString;
+use PHPCompiler\Frame;
+use PHPCompiler\Func\Internal;
+use PHPCompiler\JIT\Context;
+use PHPCompiler\JIT\Variable as JITVariable;
+use PHPCompiler\VM\BuiltinExecute;
+use PHPCompiler\VM\Variable;
+use PHPLLVM\Value;
+
+/**
+ * mb_strstr() — multibyte strstr (php-src ext/mbstring/mbstring.c).
+ */
+final class mb_strstr extends Internal
+{
+    public function __construct()
+    {
+        parent::__construct('mb_strstr');
+    }
+
+    public function execute(Frame $frame): void
+    {
+        $argc = \count($frame->calledArgs);
+        if ($argc < 2 || $argc > 4) {
+            throw new \ArgumentCountError(sprintf(
+                'mb_strstr() expects at least 2 arguments, %d given',
+                $argc
+            ));
+        }
+        $haystack = VmString::coerceStringBuiltinArg(
+            $frame->calledArgs[0],
+            'mb_strstr',
+            0,
+            'haystack'
+        );
+        if (null === $frame->returnVar) {
+            return;
+        }
+        $needle = VmString::coerceStringBuiltinArg(
+            $frame->calledArgs[1],
+            'mb_strstr',
+            1,
+            'needle'
+        );
+        $part = $argc >= 3
+            ? VmMbstring::coercePartArg($frame->calledArgs[2], 'mb_strstr', 2)
+            : false;
+        $encoding = $argc >= 4
+            ? VmMbstring::coerceEncodingArg($frame->calledArgs[3], 'mb_strstr', 3)
+            : 'UTF-8';
+        $result = VmMbstring::strstr($haystack, $needle, $part, $encoding);
+        BuiltinExecute::writeReturn($frame, static function (Variable $ret) use ($result): void {
+            if (false === $result) {
+                $ret->bool(false);
+
+                return;
+            }
+            $ret->string($result);
+        });
+    }
+
+    public function call(Context $context, JITVariable ...$args): Value
+    {
+        $argc = \count($args);
+        if ($argc < 2 || $argc > 4) {
+            throw new \LogicException('mb_strstr() requires two to four arguments');
+        }
+
+        throw new \LogicException('mb_strstr() is not lowered for JIT/AOT in this compiler build');
+    }
+}

test/compliance/cases/stdlib/mb_strstr.phpt

@@ -0,0 +1,15 @@
+--TEST--
+stdlib mb_strstr() — multibyte strstr (#19941, ext/mbstring/mbstring.c)
+--FILE--
+<?php
+var_dump(mb_strstr('Hello World', 'World'));
+var_dump(mb_strstr('Hello World', 'World', true));
+var_dump(mb_strstr('Hello World', 'xyz'));
+var_dump(mb_strstr("caf\xC3\xA9 r\xC3\xA9sum\xC3\xA9", "\xC3\xA9"));
+var_dump(mb_strstr("caf\xC3\xA9 r\xC3\xA9sum\xC3\xA9", "\xC3\xA9", true));
+--EXPECT--
+string(5) "World"
+string(6) "Hello "
+bool(false)
+string(11) "é résumé"
+string(3) "caf"