Statical analysis for Latte [WIP]

phpstan.neon

@@ -1,4 +1,8 @@
 parameters:
+	excludePaths:
+		analyse:
+			- src/Latte/Compiler/TagParser.php
+
 	level: 5
 
 	paths:

src/Latte/Compiler/Block.php

@@ -26,6 +26,7 @@ final class Block
 
 	/** @var ParameterNode[] */
 	public array $parameters = [];
+	public VariableScope $variables;
 
 
 	public function __construct(

src/Latte/Compiler/PrintContext.php

@@ -77,10 +77,14 @@ final class PrintContext
 	/** @var Escaper[] */
 	private array $escaperStack = [];
 
+	/** @var VariableScope[] */
+	private array $scopeStack = [];
+
 
 	public function __construct(string $contentType = ContentType::Html)
 	{
 		$this->escaperStack[] = new Escaper($contentType);
+		$this->scopeStack[] = new VariableScope;
 	}
 
 
@@ -160,9 +164,28 @@ public function getEscaper(): Escaper
 	}
 
 
+	public function beginVariableScope(): VariableScope
+	{
+		return $this->scopeStack[] = clone end($this->scopeStack);
+	}
+
+
+	public function restoreVariableScope(): void
+	{
+		array_pop($this->scopeStack);
+	}
+
+
+	public function getVariableScope(): VariableScope
+	{
+		return end($this->scopeStack);
+	}
+
+
 	public function addBlock(Block $block): void
 	{
 		$block->escaping = $this->getEscaper()->export();
+		$block->variables = clone $this->getVariableScope();
 		$block->method = 'block' . ucfirst(trim(preg_replace('#\W+#', '_', $block->name->print($this)), '_'));
 		$lower = strtolower($block->method);
 		$used = $this->blocks + ['block' => 1];

src/Latte/Compiler/TemplateGenerator.php

@@ -11,6 +11,8 @@
 
 use Latte;
 use Latte\ContentType;
+use Latte\Essential\Blueprint;
+use Nette\PhpGenerator as Php;
 
 
 /**
@@ -38,20 +40,24 @@ public function generate(
 		string $className,
 		?string $comment = null,
 		bool $strictMode = false,
+		array $filters = [],
 	): string {
 		$context = new PrintContext($node->contentType);
-		$code = $node->main->print($context);
-		$code = self::buildParams($code, [], '$ʟ_args', $context);
-		$this->addMethod('main', $code, 'array $ʟ_args');
+		$scope = $context->getVariableScope();
+		$this->addMethod('main', '');
 
 		$head = (new NodeTraverser)->traverse($node->head, fn(Node $node) => $node instanceof Nodes\TextNode ? new Nodes\NopNode : $node);
 		$code = $head->print($context);
 		if ($code || $context->paramsExtraction) {
 			$code .= 'return get_defined_vars();';
-			$code = self::buildParams($code, $context->paramsExtraction, '$this->params', $context);
+			$code = self::buildParams($code, $context->paramsExtraction, '$this->params', $context, $scope);
 			$this->addMethod('prepare', $code, '', 'array');
 		}
 
+		$code = $node->main->print($context);
+		$code = self::buildParams($code, [], '$ʟ_args', $context, $context->getVariableScope());
+		$this->addMethod('main', $code, 'array $ʟ_args');
+
 		if ($node->contentType !== ContentType::Html) {
 			$this->addConstant('ContentType', $node->contentType);
 		}
@@ -75,13 +81,18 @@ public function generate(
 				. ($method['body'] ? "\t\t$method[body]\n" : '') . "\t}";
 		}
 
+		$comment .= "\n@property Filters$className \$filters";
+		$comment = str_replace('*/', '* /', $comment);
+		$comment = str_replace("\n", "\n * ", "/**\n" . trim($comment)) . "\n */\n";
+
 		$code = "<?php\n\n"
 			. ($strictMode ? "declare(strict_types=1);\n\n" : '')
 			. "use Latte\\Runtime as LR;\n\n"
-			. ($comment === null ? '' : '/** ' . str_replace('*/', '* /', $comment) . " */\n")
+			. $comment
 			. "final class $className extends Latte\\Runtime\\Template\n{\n"
 			. implode("\n\n", $members)
-			. "\n}\n";
+			. "\n}\n\n\n"
+			. $this->generateStub($node, 'Filters' . $className, $filters);
 
 		$code = PhpHelpers::optimizeEcho($code);
 		$code = PhpHelpers::reformatCode($code);
@@ -100,7 +111,7 @@ private function generateBlocks(array $blocks, PrintContext $context): void
 					: [$block->method, $block->escaping];
 			}
 
-			$body = $this->buildParams($block->content, $block->parameters, '$ʟ_args', $context);
+			$body = self::buildParams($block->content, $block->parameters, '$ʟ_args', $context, $block->variables);
 			if (!$block->isDynamic() && str_contains($body, '$')) {
 				$embedded = $block->tag->name === 'block' && is_int($block->layer) && $block->layer;
 				$body = 'extract(' . ($embedded ? 'end($this->varStack)' : '$this->params') . ');' . $body;
@@ -121,16 +132,58 @@ private function generateBlocks(array $blocks, PrintContext $context): void
 	}
 
 
-	private function buildParams(string $body, array $params, string $cont, PrintContext $context): string
+	private function generateStub(Node $node, string $className, $filters): string
 	{
+		if (!class_exists(Php\ClassType::class)) {
+			return '';
+		}
+
+		$used = [];
+		(new NodeTraverser)->traverse($node, function (Node $node) use (&$used) {
+			if ($node instanceof Nodes\Php\FilterNode) {
+				$used[$node->name->name] = true;
+			}
+		});
+
+		$class = new Php\ClassType($className);
+		$filters = array_intersect_key($filters, $used);
+		foreach ($filters as $name => $callback) {
+			$func = (new Php\Factory)->fromCallable($callback);
+			$type = Blueprint::printType($func->getReturnType(), $func->isReturnNullable(), null) ?: 'mixed';
+			$params = [];
+			$list = $func->getParameters();
+			foreach ($list as $param) {
+				$variadic = $func->isVariadic() && $param === end($list);
+				$params[] = (Blueprint::printType($param->getType(), $param->isNullable(), null) ?: 'mixed')
+					. ($variadic ? '...' : '');
+			}
+
+			$class->addComment('@property callable(' . implode(', ', $params) . "): $type \$$name");
+		}
+
+		return (string) $class;
+	}
+
+
+	/**
+	 * @param Nodes\Php\ParameterNode[] $params
+	 */
+	private static function buildParams(
+		string $body,
+		array $params,
+		string $cont,
+		PrintContext $context,
+		VariableScope $scope,
+	): string {
 		if (!str_contains($body, '$') && !str_contains($body, 'get_defined_vars()')) {
 			return $body;
 		}
 
 		$res = [];
 		foreach ($params as $i => $param) {
 			$res[] = $context->format(
-				'%node = %raw[%dump] ?? %raw[%dump] ?? %node;',
+				'%raw%node = %raw[%dump] ?? %raw[%dump] ?? %node;',
+				$param->type ? VariableScope::printComment($param->var->name, $param->type->type) . ' ' : '',
 				$param->var,
 				$cont,
 				$i,
@@ -143,7 +196,10 @@ private function buildParams(string $body, array $params, string $cont, PrintCon
 		$extract = $params
 			? implode('', $res) . 'unset($ʟ_args);'
 			: "extract($cont);" . (str_contains($cont, '$this') ? '' : "unset($cont);");
-		return $extract . "\n\n" . $body;
+
+		return $extract . "\n"
+			. $scope->extractTypes() . "\n\n"
+			. $body;
 	}
 
 

src/Latte/Compiler/VariableScope.php

@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * This file is part of the Latte (https://latte.nette.org)
+ * Copyright (c) 2008 David Grudl (https://davidgrudl.com)
+ */
+
+declare(strict_types=1);
+
+namespace Latte\Compiler;
+
+use Latte;
+
+
+final class VariableScope
+{
+	use Latte\Strict;
+
+	/** @var string[] */
+	public array $types = [];
+
+
+	public function addVariable(string $name, ?string $type): string
+	{
+		return $this->types[$name] = $this->printComment($name, $type);
+	}
+
+
+	public function addExpression(Nodes\Php\ExpressionNode $expr, ?Nodes\Php\SuperiorTypeNode $type): string
+	{
+		return $expr instanceof Nodes\Php\Expression\VariableNode && is_string($expr->name)
+			? $this->addVariable($expr->name, $type?->type)
+			: '';
+	}
+
+
+	public static function printComment(string $name, ?string $type): string
+	{
+		if (!$type) {
+			return '';
+		}
+		$str = '@var ' . $type . ' $' . $name;
+		return '/** ' . str_replace('*/', '* /', $str) . ' */';
+	}
+
+
+	public function extractTypes(): string
+	{
+		return implode('', $this->types) . "\n";
+	}
+}

src/Latte/Engine.php

@@ -191,6 +191,7 @@ public function generate(TemplateNode $node, string $name): string
 			$this->getTemplateClass($name),
 			$comment,
 			$this->strictTypes,
+			$this->getFilters(),
 		);
 	}
 

src/Latte/Essential/Blueprint.php

@@ -95,7 +95,7 @@ public function addFunctions(Php\ClassType $class, array $funcs): void
 	}
 
 
-	private function printType(?string $type, bool $nullable, ?Php\PhpNamespace $namespace): string
+	public static function printType(?string $type, bool $nullable, ?Php\PhpNamespace $namespace): string
 	{
 		if ($type === null) {
 			return '';
@@ -123,7 +123,7 @@ public function printParameters(
 		$list = $function->getParameters();
 		foreach ($list as $param) {
 			$variadic = $function->isVariadic() && $param === end($list);
-			$params[] = ltrim($this->printType($param->getType(), $param->isNullable(), $namespace) . ' ')
+			$params[] = ltrim(self::printType($param->getType(), $param->isNullable(), $namespace) . ' ')
 				. ($param->isReference() ? '&' : '')
 				. ($variadic ? '...' : '')
 				. '$' . $param->getName()

src/Latte/Essential/Nodes/BlockNode.php

@@ -74,14 +74,20 @@ public static function create(Tag $tag, TemplateParser $parser): \Generator
 
 	public function print(PrintContext $context): string
 	{
-		if (!$this->block) {
-			return $this->printFilter($context);
+		$context->beginVariableScope();
+		try {
+			if (!$this->block) {
+				return $this->printFilter($context);
 
-		} elseif ($this->block->isDynamic()) {
-			return $this->printDynamic($context);
-		}
+			} elseif ($this->block->isDynamic()) {
+				return $this->printDynamic($context);
 
-		return $this->printStatic($context);
+			} else {
+				return $this->printStatic($context);
+			}
+		} finally {
+			$context->restoreVariableScope();
+		}
 	}
 
 
@@ -91,7 +97,9 @@ private function printFilter(PrintContext $context): string
 			<<<'XX'
 				ob_start(fn() => '') %line;
 				try {
-					(function () { extract(func_get_arg(0));
+					(function () {
+						extract(func_get_arg(0));
+						%raw
 						%node
 					})(get_defined_vars());
 				} finally {
@@ -101,6 +109,7 @@ private function printFilter(PrintContext $context): string
 
 				XX,
 			$this->position,
+			$context->getVariableScope()->extractTypes(),
 			$this->content,
 			$context->getEscaper()->export(),
 			$this->modifier,

src/Latte/Essential/Nodes/ForeachNode.php

@@ -88,6 +88,12 @@ private static function parseArguments(TagParser $parser, self $node): void
 
 	public function print(PrintContext $context): string
 	{
+		$scope = $context->getVariableScope();
+		if ($this->key) {
+			$scope->addExpression($this->key, null);
+		}
+		$scope->addExpression($this->value, null);
+
 		$content = $this->content->print($context);
 		$iterator = $this->else || ($this->iterator ?? preg_match('#\$iterator\W|\Wget_defined_vars\W#', $content));
 

src/Latte/Essential/Nodes/TemplateTypeNode.php

@@ -13,26 +13,50 @@
 use Latte\Compiler\Nodes\StatementNode;
 use Latte\Compiler\PrintContext;
 use Latte\Compiler\Tag;
+use Latte\Compiler\Token;
 
 
 /**
  * {templateType ClassName}
  */
 class TemplateTypeNode extends StatementNode
 {
+	public string $class;
+
+
 	public static function create(Tag $tag): static
 	{
 		if (!$tag->isInHead()) {
 			throw new CompileException('{templateType} is allowed only in template header.', $tag->position);
 		}
 		$tag->expectArguments('class name');
-		$tag->parser->parseExpression();
-		return new static;
+		$token = $tag->parser->stream->consume(Token::Php_Identifier, Token::Php_NameQualified, Token::Php_NameFullyQualified);
+		if (!class_exists($token->text)) {
+			throw new CompileException("Class '$token->text' used in {templateType} doesn't exist.", $token->position);
+		}
+
+		$node = new static;
+		$node->class = $token->text;
+		return $node;
 	}
 
 
 	public function print(PrintContext $context): string
 	{
+		$scope = $context->getVariableScope();
+		$rc = new \ReflectionClass($this->class);
+		foreach ($rc->getProperties(\ReflectionProperty::IS_PUBLIC) as $property) {
+			$type = $this->parseAnnotation($property->getDocComment() ?: '') ?: (string) $property->getType();
+			$scope->addVariable($property->getName(), $type);
+		}
+
 		return '';
 	}
+
+
+	private function parseAnnotation(string $comment): ?string
+	{
+		$comment = trim($comment, '/*');
+		return preg_match('#@var ([^$]+)#', $comment, $m) ? trim($m[1]) : null;
+	}
 }