Infer static variables whose @var tag @phpstan-ignore-var ignores

Author: jack-worman

src/Analyser/Generics/StaticVariableInference.php

@@ -389,8 +389,15 @@ private static function collectRootNames(Expr $expr, array &$names): void
 	private static function hasVarTag(Node\Stmt\Static_ $stmt): bool
 	{
 		$docComment = $stmt->getDocComment();
+		if ($docComment === null) {
+			return false;
+		}
+
+		$text = $docComment->getText();
 
-		return $docComment !== null && preg_match('~@(?:phpstan-|psalm-)?var\s~', $docComment->getText()) === 1;
+		// a @var tag ignored by @phpstan-ignore-var does not type the variable, so it is inferred
+		return preg_match('~@(?:phpstan-|psalm-)?var\s~', $text) === 1
+			&& preg_match('~@phpstan-ignore-var\b~', $text) !== 1;
 	}
 
 }

tests/PHPStan/Analyser/nsrt/phpstan-ignore-var.php

@@ -63,3 +63,14 @@ function doBaz(int $i): void
 	echo $i;
 	assertType('int', $i);
 }
+
+function doStatic(int $i): void
+{
+	/**
+	 * @var array<int, string> $cache
+	 * @phpstan-ignore-var
+	 */
+	static $cache = [];
+	assertType('array<int, \'x\'>', $cache);
+	$cache[$i] = 'x';
+}

turbo-ext/src/StaticVariableInference.cpp

@@ -137,12 +137,30 @@ bool declaresVar(zend_string *text)
 	return false;
 }
 
+/* preg_match('~@phpstan-ignore-var\b~', $text) === 1 */
+bool ignoresVar(zend_string *text)
+{
+	const char *s = ZSTR_VAL(text);
+	size_t n = ZSTR_LEN(text);
+	const char tag[] = "@phpstan-ignore-var";
+	const size_t len = sizeof(tag) - 1;
+	for (size_t i = 0; i + len <= n; i++) {
+		if (s[i] != '@' || memcmp(s + i, tag, len) != 0) continue;
+		// \b after the word character 'r': the end of the text or a non-word character
+		if (i + len == n) return true;
+		char c = s[i + len];
+		bool isWord = (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_';
+		if (!isWord) return true;
+	}
+	return false;
+}
+
 /* Mirrors the private hasVarTag(); false = pending exception */
 [[nodiscard]] bool hasVarTag(zval *stmt, bool &out)
 {
 	zv::Val text = pt_node_doc_comment_text(stmt);
 	if (UNEXPECTED(text.isUndef())) return false;
-	out = text.ref().isString() && declaresVar(Z_STR_P(text.raw()));
+	out = text.ref().isString() && declaresVar(Z_STR_P(text.raw())) && !ignoresVar(Z_STR_P(text.raw()));
 	return true;
 }