Add namespace to function names when looking for pass-by-reference

Author: sirbrillig

Diff for: VariableAnalysis/Lib/Helpers.php

@@ -1658,6 +1658,41 @@ public static function isConstructorPromotion(File $phpcsFile, $stackPtr)
 		return false;
 	}
 
+	/**
+	 * If looking at a function call token, return a string for the full function
+	 * name including any inline namespace.
+	 *
+	 * So for example, if the call looks like `\My\Namespace\doSomething($bar)`
+	 * and `$stackPtr` refers to `doSomething`, this will return
+	 * `\My\Namespace\doSomething`.
+	 *
+	 * @param File $phpcsFile
+	 * @param int  $stackPtr
+	 *
+	 * @return string|null
+	 */
+	public static function getFunctionNameWithNamespace(File $phpcsFile, $stackPtr)
+	{
+		$tokens = $phpcsFile->getTokens();
+
+		if (! isset($tokens[$stackPtr])) {
+			return null;
+		}
+		$startOfScope = self::findVariableScope($phpcsFile, $stackPtr);
+		$functionName = $tokens[$stackPtr]['content'];
+
+		// Move backwards from the token, collecting namespace separators and
+		// strings, until we encounter whitespace or something else.
+		$partOfNamespace = [T_NS_SEPARATOR, T_STRING];
+		for ($i = $stackPtr - 1; $i > $startOfScope; $i--) {
+			if (! in_array($tokens[$i]['code'], $partOfNamespace, true)) {
+				break;
+			}
+			$functionName = "{$tokens[$i]['content']}{$functionName}";
+		}
+		return $functionName;
+	}
+
 	/**
 	 * Return false if the token is definitely not part of a typehint
 	 *

Diff for: VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php

@@ -153,6 +153,13 @@ class VariableAnalysisSniff implements Sniff
 	 */
 	public $allowUnusedVariablesBeforeRequire = false;
 
+	/**
+	 * A cache for getPassByReferenceFunctions
+	 *
+	 * @var array<array<int|string>>
+	 */
+	private $passByRefFunctionsCache = [];
+
 	public function __construct()
 	{
 		$this->scopeManager = new ScopeManager();
@@ -195,6 +202,20 @@ public function register()
 	 */
 	private function getPassByReferenceFunction($functionName)
 	{
+		$passByRefFunctions = $this->getPassByReferenceFunctions();
+		return isset($passByRefFunctions[$functionName]) ? $passByRefFunctions[$functionName] : [];
+	}
+
+	/**
+	 * @param string $functionName
+	 *
+	 * @return array<array<int|string>>
+	 */
+	private function getPassByReferenceFunctions()
+	{
+		if ($this->passByRefFunctionsCache) {
+			return $this->passByRefFunctionsCache;
+		}
 		$passByRefFunctions = Constants::getPassByReferenceFunctions();
 		if (!empty($this->sitePassByRefFunctions)) {
 			$lines = Helpers::splitStringToArray('/\s+/', trim($this->sitePassByRefFunctions));
@@ -206,7 +227,8 @@ private function getPassByReferenceFunction($functionName)
 		if ($this->allowWordPressPassByRefFunctions) {
 			$passByRefFunctions = array_merge($passByRefFunctions, Constants::getWordPressPassByReferenceFunctions());
 		}
-		return isset($passByRefFunctions[$functionName]) ? $passByRefFunctions[$functionName] : [];
+		$this->passByRefFunctionsCache = $passByRefFunctions;
+		return $passByRefFunctions;
 	}
 
 	/**
@@ -1485,7 +1507,12 @@ protected function processVariableAsPassByReferenceFunctionCall(File $phpcsFile,
 		$functionName = $tokens[$functionPtr]['content'];
 		$refArgs = $this->getPassByReferenceFunction($functionName);
 		if (! $refArgs) {
-			return false;
+			// Check again with the fully namespaced function name.
+			$functionName = Helpers::getFunctionNameWithNamespace($phpcsFile, $functionPtr);
+			$refArgs = $this->getPassByReferenceFunction($functionName);
+			if (! $refArgs) {
+				return false;
+			}
 		}
 
 		$argPtrs = Helpers::findFunctionCallArguments($phpcsFile, $stackPtr);