我正在使用PHP-PARser來查找 PHP 程序的 AST。例如：代碼<?phpuse PhpParser\Error;use PhpParser\NodeDumper;use PhpParser\ParserFactory;$code = <<<'CODE'<?php$variable = $_POST['first'];$new = $nonexist; CODE;$parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);try { $ast = $parser->parse($code);} catch (Error $error) { echo "Parse error: {$error->getMessage()}\n"; return;}$dumper = new NodeDumper;echo $dumper->dump($ast) . "\n";上面例子的AST結(jié)果如下：array( 0: Stmt_Expression( expr: Expr_Assign( var: Expr_Variable( name: variable ) expr: Expr_ArrayDimFetch( var: Expr_Variable( name: _POST_first_symbol ) dim: Scalar_String( value: first ) ) ) ) 1: Stmt_Expression( expr: Expr_Assign( var: Expr_Variable( name: new ) expr: Expr_Variable( name: nonexist ) ) ) )我要查找的是variable = _POSTANDnew = nonexist 我使用leavenode函數(shù)來達(dá)到_POSTand variable。我要查找的代碼_POST如下variable：public function leaveNode(Node $node) { $collect_to_print= array(); if ($node instanceof ArrayDimFetch && $node->var instanceof Variable && $node->var->name === '_POST') { $variableName = (string) $node->var->name; $collect_to_print[$node->dim->value] = $node->var->name; // will store the variables in array in a way to print them all later such as variable => _POST , how to get the name `variable` in this case return $node; } else if ($node instanceof Variable && !($node->var->name === '_POST' )) { $collect_to_print[$node->name] = 'Empty' ; } }到目前為止，我的結(jié)果在單獨(dú)的行中顯示每個(gè)變量，如下所示：variable => first => _POST // This _POST should be the value of variable (above)new => Emptynonexist => Empty但是，我希望結(jié)果是：variable => _POSTnew => Emptynonexist => Empty請幫忙
1 回答
慕絲7291255
TA貢獻(xiàn)1859條經(jīng)驗(yàn) 獲得超6個(gè)贊
這比您提出的其他問題要復(fù)雜得多，但是了解如何編寫它很有趣。
我已經(jīng)在代碼中添加了注釋，但基本上它會(huì)分析代碼并查找分配（PhpParser\Node\Expr\Assign節(jié)點(diǎn)實(shí)例）。然后它將它分成左右兩部分，并遞歸地提取兩部分中的任何變量。
該代碼允許在表達(dá)式的任一側(cè)嵌套變量，我更改了示例代碼以提供一些更廣泛的示例。
代碼中的注釋（假定了解解析器如何與節(jié)點(diǎn)等一起工作）...
$traverser = new NodeTraverser;
class ExtractVars extends NodeVisitorAbstract {
private $prettyPrinter = null;
private $variables = [];
private $expressions = [];
public function __construct() {
$this->prettyPrinter = new PhpParser\PrettyPrinter\Standard;
}
public function leaveNode(Node $node) {
if ( $node instanceof PhpParser\Node\Expr\Assign ) {
$assignVars = $this->extractVarRefs ( $node->var );
// Get string of what assigned to actually is
$assign = $this->prettyPrinter->prettyPrintExpr($node->var);
// Store the variables associated with the left hand side
$this->expressions[$assign]["to"] = $assignVars;
// Store variables from right
$this->expressions[$assign][] = $this->extractVarRefs ( $node->expr );
}
}
private function extractVarRefs ( Node $node ) : array {
$variableList = [];
// If it's a variable, store the name
if ( $node instanceof PhpParser\Node\Expr\Variable ) {
$variable = $this->prettyPrinter->prettyPrintExpr($node);
$this->variables[] = $variable;
$variableList[] = $variable;
}
// Look for any further variables in the node
foreach ( $node->getSubNodeNames() as $newNodeName ) {
$newNode = $node->$newNodeName;
if ( $newNode instanceof Node && $newNode->getSubNodeNames()) {
// Recursive call to extract variables
$toAdd = $this->extractVarRefs ( $newNode );
// Add new list to current list
$variableList = array_merge($variableList, $toAdd);
}
}
return $variableList;
}
public function getVariables() : array {
return array_unique($this->variables);
}
public function getExpressions() : array {
return $this->expressions;
}
}
$varExtract = new ExtractVars();
$traverser->addVisitor ($varExtract);
$traverser->traverse($ast);
print_r($varExtract->getVariables());
print_r($varExtract->getExpressions());
其中給出了變量列表...
Array
(
[0] => $_POST
[1] => $b
[3] => $new
[4] => $nonexist
)
表達(dá)式列表為
Array
(
[$_POST[$b]] => Array
(
[to] => Array
(
[0] => $_POST
[1] => $b
)
[0] => Array
(
[0] => $_POST
)
)
[$new] => Array
(
[to] => Array
(
[0] => $new
)
[0] => Array
(
[0] => $nonexist
)
[1] => Array
(
[0] => $_POST
[1] => $b
)
)
)
請注意，[to]數(shù)組的元素包含 . 左側(cè)涉及的所有變量=。
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