Introduce Script & Func structures

This means that each function now has its own control flow graph and own variable space. Also resolves some state pollution issues between different functions, e.g. regarding labels.
ircmaxell · Mar 22, 2016 · 0d54187 · 0d54187
1 parent fe6731a
commit 0d54187
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Showing 18 changed files with 252 additions and 157 deletions.
diff --git a/demo.php b/demo.php
@@ -23,9 +23,9 @@ function foo(array $a) {
 EOF;
 
 
-$block = $parser->parse($code, __FILE__);
-$traverser->traverse($block);
+$script = $parser->parse($code, __FILE__);
+$traverser->traverse($script);
 
 $dumper = new PHPCfg\Printer\Text();
-echo $dumper->printCFG(array($block));
+echo $dumper->printScript($script);
 
diff --git a/lib/PHPCfg/Func.php b/lib/PHPCfg/Func.php
@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of PHP-CFG, a Control flow graph implementation for PHP
+ *
+ * @copyright 2015 Anthony Ferrara. All rights reserved
+ * @license MIT See LICENSE at the root of the project for more info
+ */
+
+namespace PHPCfg;
+
+class Func {
+    /** @var string */
+    public $name;
+    /** @var bool */
+    public $returnsRef;
+    /** @var */
+    public $returnType;
+    /** @var */
+    public $class;
+    /** @var Op\Expr\Param[] */
+    public $params;
+    /** @var Block|null */
+    public $cfg;
+
+    public function __construct($name, $returnsRef, $returnType, $class) {
+        $this->name = $name;
+        $this->returnsRef = $returnsRef;
+        $this->returnType = $returnType;
+        $this->class = $class;
+        $this->params = [];
+        $this->cfg = new Block;
+    }
+}
diff --git a/lib/PHPCfg/Op/CallableOp.php b/lib/PHPCfg/Op/CallableOp.php
@@ -9,8 +9,11 @@
 
 namespace PHPCfg\Op;
 
+use PHPCfg\Func;
+
 interface CallableOp {
 
-    public function getParams();
+    /** @returns Func */
+    public function getFunc();
 
 }
diff --git a/lib/PHPCfg/Op/Expr/Closure.php b/lib/PHPCfg/Op/Expr/Closure.php
@@ -9,38 +9,22 @@
 
 namespace PHPCfg\Op\Expr;
 
-use PhpCfg\Block;
+use PHPCfg\Func;
 use PHPCfg\Op\CallableOp;
 use PHPCfg\Op\Expr;
 
 class Closure extends Expr implements CallableOp {
-    public $byRef;
-
-    public $params;
-
-    public $returnType;
-
-    public $stmts;
-
-    public $globals;
-
+    public $func;
     public $useVars;
 
-    public function __construct(array $params, array $useVars, $byRef, $returnType, Block $stmts, array $attributes = []) {
+    public function __construct(Func $func, array $useVars, array $attributes = []) {
         parent::__construct($attributes);
-        $this->params = $this->addReadRef($params);
+        $this->func = $func;
         $this->useVars = $this->addReadRef($useVars);
-        $this->byRef = (bool) $byRef;
-        $this->returnType = $returnType;
-        $this->stmts = $stmts;
-    }
-
-    public function getParams() {
-        return $this->params;
     }
 
-    public function getSubBlocks() {
-        return ['stmts'];
+    public function getFunc() {
+        return $this->func;
     }
 
     public function getVariableNames() {

diff --git a/lib/PHPCfg/Op/Stmt/ClassMethod.php b/lib/PHPCfg/Op/Stmt/ClassMethod.php
@@ -9,14 +9,5 @@
 
 namespace PHPCfg\Op\Stmt;
 
-use PHPCfg\Block;
-use PHPCfg\Operand;
-
 class ClassMethod extends Function_ {
-    public $class;
-
-    public function __construct(Operand $class, $name, array $params, $byRef, $returnType, Block $stmts = null, array $attributes = []) {
-        parent::__construct($name, $params, $byRef, $returnType, $stmts, $attributes);
-        $this->class = $this->addReadRef($class);
-    }
 }
diff --git a/lib/PHPCfg/Op/Stmt/Function_.php b/lib/PHPCfg/Op/Stmt/Function_.php
@@ -9,42 +9,23 @@
 
 namespace PHPCfg\Op\Stmt;
 
-use PhpCfg\Block;
+use PHPCfg\Func;
 use PHPCfg\Op\CallableOp;
 use PHPCfg\Op\Stmt;
 
 class Function_ extends Stmt implements CallableOp {
-    public $byRef;
+    public $func;
 
-    public $name;
-
-    public $params;
-
-    public $paramVars = [];
-
-    public $returnType;
-
-    public $stmts;
-
-    public $globals;
-
-    public function __construct($name, array $params, $byRef, $returnType, Block $stmts = null, array $attributes = []) {
+    public function __construct(Func $func, array $attributes = []) {
         parent::__construct($attributes);
-        $this->name = $this->addReadRef($name);
-        $this->params = $params;
-        foreach ($params as $param) {
-            $this->paramVars[] = $this->addReadRef($param->result);
-        }
-        $this->byRef = (bool) $byRef;
-        $this->returnType = $returnType;
-        $this->stmts = $stmts;
+        $this->func = $func;
     }
 
-    public function getSubBlocks() {
-        return ['stmts'];
+    public function getFunc() {
+        return $this->func;
     }
 
-    public function getParams() {
-        return $this->params;
+    public function getSubBlocks() {
+        return [];
     }
 }
diff --git a/lib/PHPCfg/Parser.php b/lib/PHPCfg/Parser.php
@@ -39,7 +39,9 @@ class Parser {
 
     /** @var Literal|null */
     protected $currentClass = null;
-
+    /** @var Script */
+    protected $script;
+    protected $anonId = 0;
 
     public function __construct(AstParser $astParser, AstTraverser $astTraverser = null) {
         $this->astParser = $astParser;
@@ -54,14 +56,46 @@ public function __construct(AstParser $astParser, AstTraverser $astTraverser = n
         $this->incompletePhis = new \SplObjectStorage;
     }
 
+    /**
+     * @param string $code
+     * @param string $fileName
+     * @returns Script
+     */
     public function parse($code, $fileName) {
-        $this->labels = [];
         $this->fileName = $fileName;
         $ast = $this->astParser->parse($code);
         $ast = $this->astTraverser->traverse($ast);
 
+        $this->script = $script = new Script();
+        $script->functions = [];
+        $script->main = new Func('{main}', false, null, null);
+        $this->parseFunc($script->main, [], $ast);
+
+        // Reset script specific state
+        $this->script = null;
+        $this->currentClass = null;
+
+        return $script;
+    }
+
+    protected function parseFunc(Func $func, array $params, array $stmts) {
+        // Back up function specific structures
+        $prevScope = $this->scope;
+        $prevIncompletePhis = $this->incompletePhis;
+        $prevLabels = $this->labels;
+        $this->scope = new \SplObjectStorage;
+        $this->incompletePhis = new \SplObjectStorage;
+        $this->labels = [];
+
+        $start = $func->cfg;
+
         $this->complete = false;
-        $this->parseNodes($ast, $start = new Block);
+        $func->params = $this->parseParameterList($func, $params);
+        foreach ($func->params as $param) {
+            $this->writeVariableName($param->name->value, $param->result, $start);
+        }
+
+        $this->parseNodes($stmts, $start);
         $this->complete = true;
 
         foreach ($this->incompletePhis as $block) {
@@ -78,8 +112,10 @@ public function parse($code, $fileName) {
                 $block->phi[] = $phi;
             }
         }
-        $this->incompletePhis->removeAllExcept(new \SplObjectStorage);
-        return $start;
+
+        $this->scope = $prevScope;
+        $this->incompletePhis = $prevIncompletePhis;
+        $this->labels = $prevLabels;
     }
 
     public function parseNodes(array $nodes, Block $block) {
@@ -143,28 +179,22 @@ protected function parseStmt_ClassMethod(Stmt\ClassMethod $node) {
         if (!$this->currentClass instanceof Operand) {
             throw new \RuntimeException("Unknown current class");
         }
-        $params = $this->parseParameterList($node->params);
-        if ($node->stmts) {
-            $block = new Block;
-            foreach ($params as $param) {
-                $this->writeVariableName($param->name->value, $param->result, $block);
-            }
-            $this->parseNodes($node->stmts, $block);
-        } else {
-            $block = null;
-        }
-        $this->block->children[] = $func = new Op\Stmt\ClassMethod(
-            $this->currentClass,
-            $this->parseExprNode($node->name),
-            $params,
+
+        $this->script->functions[] = $func = new Func(
+            $node->name,
             $node->byRef,
             $this->parseExprNode($node->returnType),
-            $block,
-            $this->mapAttributes($node)
+            $this->currentClass
         );
-        foreach ($params as $param) {
-            $param->function = $func;
+
+        if ($node->stmts) {
+            $this->parseFunc($func, $node->params, $node->stmts);
+        } else {
+            $func->params = $this->parseParameterList($func, $node->params);
+            $func->cfg = null;
         }
+
+        $this->block->children[] = new Op\Stmt\ClassMethod($func, $this->mapAttributes($node));
     }
 
     protected function parseStmt_Const(Stmt\Const_ $node) {
@@ -281,23 +311,14 @@ protected function parseStmt_Foreach(Stmt\Foreach_ $node) {
     }
 
     protected function parseStmt_Function(Stmt\Function_ $node) {
-        $block = new Block;
-        $params = $this->parseParameterList($node->params);
-        foreach ($params as $param) {
-            $this->writeVariableName($param->name->value, $param->result, $block);
-        }
-        $this->parseNodes($node->stmts, $block);
-        $this->block->children[] = $func = new Op\Stmt\Function_(
-            $this->parseExprNode($node->namespacedName),
-            $params,
+        $this->script->functions[] = $func = new Func(
+            $node->namespacedName,
             $node->byRef,
             $this->parseExprNode($node->returnType),
-            $block,
-            $this->mapAttributes($node)
+            null
         );
-        foreach ($params as $param) {
-            $param->function = $func;
-        }
+        $this->parseFunc($func, $node->params, $node->stmts);
+        $this->block->children[] = new Op\Stmt\Function_($func, $this->mapAttributes($node));
     }
 
     protected function parseStmt_Global(Stmt\Global_ $node) {
@@ -812,8 +833,6 @@ protected function parseExpr_BooleanNot(Expr\BooleanNot $expr) {
     }
 
     protected function parseExpr_Closure(Expr\Closure $expr) {
-        $block = new Block;
-        $this->parseNodes($expr->stmts, $block);
         $uses = [];
         foreach ($expr->uses as $use) {
             $uses[] = new Operand\BoundVariable(
@@ -822,14 +841,16 @@ protected function parseExpr_Closure(Expr\Closure $expr) {
                 Operand\BoundVariable::SCOPE_LOCAL
             );
         }
-        return new Op\Expr\Closure(
-            $this->parseParameterList($expr->params),
-            $uses,
+
+        $this->script->functions[] = $func = new Func(
+            '{anonymous}#' . ++$this->anonId,
             $expr->byRef,
             $this->parseExprNode($expr->returnType),
-            $block,
-            $this->mapAttributes($expr)
+            null
         );
+        $this->parseFunc($func, $expr->params, $expr->stmts);
+
+        return new Op\Expr\Closure($func, $uses, $this->mapAttributes($expr));
     }
 
     protected function parseExpr_ClassConstFetch(Expr\ClassConstFetch $expr) {
@@ -1127,7 +1148,7 @@ private function parseScalarNode(Node\Scalar $scalar) {
         }
     }
 
-    private function parseParameterList(array $params) {
+    private function parseParameterList(Func $func, array $params) {
         if (empty($params)) {
             return [];
         }
@@ -1152,6 +1173,7 @@ private function parseParameterList(array $params) {
                 $this->mapAttributes($param)
             );
             $p->result->original = new Operand\Variable(new Operand\Literal($p->name->value));
+            $p->function = $func;
         }
         return $result;
     }