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php-language-server/src/CompletionProvider.php

492 lines
18 KiB
PHP

<?php
declare(strict_types = 1);
namespace LanguageServer;
use LanguageServer\Index\ReadableIndex;
use LanguageServer\Protocol\{
TextEdit,
Range,
Position,
CompletionList,
CompletionItem,
CompletionItemKind
};
use Microsoft\PhpParser;
use Microsoft\PhpParser\Node;
use Generator;
class CompletionProvider
{
const KEYWORDS = [
'?>',
'__halt_compiler',
'abstract',
'and',
'array',
'as',
'break',
'callable',
'case',
'catch',
'class',
'clone',
'const',
'continue',
'declare',
'default',
'die',
'do',
'echo',
'else',
'elseif',
'empty',
'enddeclare',
'endfor',
'endforeach',
'endif',
'endswitch',
'endwhile',
'eval',
'exit',
'extends',
'false',
'final',
'finally',
'for',
'foreach',
'function',
'global',
'goto',
'if',
'implements',
'include',
'include_once',
'instanceof',
'insteadof',
'interface',
'isset',
'list',
'namespace',
'new',
'null',
'or',
'print',
'private',
'protected',
'public',
'require',
'require_once',
'return',
'static',
'switch',
'throw',
'trait',
'true',
'try',
'unset',
'use',
'var',
'while',
'xor',
'yield'
];
/**
* @var DefinitionResolver
*/
private $definitionResolver;
/**
* @var Project
*/
private $project;
/**
* @var ReadableIndex
*/
private $index;
/**
* @param DefinitionResolver $definitionResolver
* @param ReadableIndex $index
*/
public function __construct(DefinitionResolver $definitionResolver, ReadableIndex $index)
{
$this->definitionResolver = $definitionResolver;
$this->index = $index;
}
/**
* Returns suggestions for a specific cursor position in a document
*
* @param PhpDocument $doc The opened document
* @param Position $pos The cursor position
* @return CompletionList
*/
public function provideCompletion(PhpDocument $doc, Position $pos): CompletionList
{
// This can be made much more performant if the tree follows specific invariants.
$node = $doc->getNodeAtPosition($pos);
// Get the node at the position under the cursor
$offset = $node === null ? -1 : $pos->toOffset($node->getFileContents());
if (
$node !== null
&& $offset > $node->getEndPosition()
&& $node->parent !== null
&& $node->parent->getLastChild() instanceof PhpParser\MissingToken
) {
$node = $node->parent;
}
$list = new CompletionList;
$list->isIncomplete = true;
if ($node instanceof Node\Expression\Variable &&
$node->parent instanceof Node\Expression\ObjectCreationExpression &&
$node->name instanceof PhpParser\MissingToken
) {
$node = $node->parent;
}
// Inspect the type of expression under the cursor
if ($node === null || $node instanceof Node\Statement\InlineHtml || $pos == new Position(0, 0)) {
// HTML, beginning of file
// Inside HTML and at the beginning of the file, propose <?php
$item = new CompletionItem('<?php', CompletionItemKind::KEYWORD);
$item->textEdit = new TextEdit(
new Range($pos, $pos),
stripStringOverlap($doc->getRange(new Range(new Position(0, 0), $pos)), '<?php')
);
$list->items[] = $item;
} elseif (
$node instanceof Node\Expression\Variable
&& !(
$node->parent instanceof Node\Expression\ScopedPropertyAccessExpression
&& $node->parent->memberName === $node
)
) {
// Variables
//
// $|
// $a|
// Find variables, parameters and use statements in the scope
$namePrefix = $node->getName() ?? '';
foreach ($this->suggestVariablesAtNode($node, $namePrefix) as $var) {
$item = new CompletionItem;
$item->kind = CompletionItemKind::VARIABLE;
$item->label = '$' . $var->getName();
$item->documentation = $this->definitionResolver->getDocumentationFromNode($var);
$item->detail = (string)$this->definitionResolver->getTypeFromNode($var);
$item->textEdit = new TextEdit(
new Range($pos, $pos),
stripStringOverlap($doc->getRange(new Range(new Position(0, 0), $pos)), $item->label)
);
$list->items[] = $item;
}
} elseif ($node instanceof Node\Expression\MemberAccessExpression) {
// Member access expressions
//
// $a->c|
// $a->|
// Multiple prefixes for all possible types
$fqns = FqnUtilities\getFqnsFromType(
$this->definitionResolver->resolveExpressionNodeToType($node->dereferencableExpression)
);
// Add the object access operator to only get members of all parents
$prefixes = [];
foreach ($this->expandParentFqns($fqns) as $prefix) {
$prefixes[] = $prefix . '->';
}
// Collect all definitions that match any of the prefixes
foreach ($this->index->getDefinitions() as $fqn => $def) {
foreach ($prefixes as $prefix) {
if (substr($fqn, 0, strlen($prefix)) === $prefix && $def->isMember) {
$list->items[] = CompletionItem::fromDefinition($def);
}
}
}
} elseif (
($scoped = $node->parent) instanceof Node\Expression\ScopedPropertyAccessExpression ||
($scoped = $node) instanceof Node\Expression\ScopedPropertyAccessExpression
) {
// Static class members and constants
//
// A\B\C::$a|
// A\B\C::|
// A\B\C::$|
// A\B\C::foo|
//
// TODO: $a::|
// Resolve all possible types to FQNs
$fqns = FqnUtilities\getFqnsFromType(
$classType = $this->definitionResolver->resolveExpressionNodeToType($scoped->scopeResolutionQualifier)
);
// Append :: operator to only get static members of all parents
$prefixes = [];
foreach ($this->expandParentFqns($fqns) as $prefix) {
$prefixes[] = $prefix . '::';
}
// Collect all definitions that match any of the prefixes
foreach ($this->index->getDefinitions() as $fqn => $def) {
foreach ($prefixes as $prefix) {
if (substr(strtolower($fqn), 0, strlen($prefix)) === strtolower($prefix) && $def->isMember) {
$list->items[] = CompletionItem::fromDefinition($def);
}
}
}
} elseif (
ParserHelpers\isConstantFetch($node)
// Creation gets set in case of an instantiation (`new` expression)
|| ($creation = $node->parent) instanceof Node\Expression\ObjectCreationExpression
|| (($creation = $node) instanceof Node\Expression\ObjectCreationExpression)
) {
// Class instantiations, function calls, constant fetches, class names
//
// new MyCl|
// my_func|
// MY_CONS|
// MyCla|
// The name Node under the cursor
$nameNode = isset($creation) ? $creation->classTypeDesignator : $node;
/** The typed name */
$prefix = $nameNode instanceof Node\QualifiedName
? (string)PhpParser\ResolvedName::buildName($nameNode->nameParts, $nameNode->getFileContents())
: $nameNode->getText($node->getFileContents());
$prefixLen = strlen($prefix);
/** Whether the prefix is qualified (contains at least one backslash) */
$isQualified = $nameNode instanceof Node\QualifiedName && $nameNode->isQualifiedName();
/** Whether the prefix is fully qualified (begins with a backslash) */
$isFullyQualified = $nameNode instanceof Node\QualifiedName && $nameNode->isFullyQualifiedName();
/** The closest NamespaceDefinition Node */
$namespaceNode = $node->getNamespaceDefinition();
/** @var string The name of the namespace */
$namespacedPrefix = null;
if ($namespaceNode) {
$namespacedPrefix = (string)PhpParser\ResolvedName::buildName($namespaceNode->name->nameParts, $node->getFileContents()) . '\\' . $prefix;
$namespacedPrefixLen = strlen($namespacedPrefix);
}
// Get the namespace use statements
// TODO: use function statements, use const statements
/** @var string[] $aliases A map from local alias to fully qualified name */
list($aliases,,) = $node->getImportTablesForCurrentScope();
foreach ($aliases as $alias => $name) {
$aliases[$alias] = (string)$name;
}
// If there is a prefix that does not start with a slash, suggest `use`d symbols
if ($prefix && !$isFullyQualified) {
foreach ($aliases as $alias => $fqn) {
// Suggest symbols that have been `use`d and match the prefix
if (substr($alias, 0, $prefixLen) === $prefix && ($def = $this->index->getDefinition($fqn))) {
$list->items[] = CompletionItem::fromDefinition($def);
}
}
}
// Suggest global symbols that either
// - start with the current namespace + prefix, if the Name node is not fully qualified
// - start with just the prefix, if the Name node is fully qualified
foreach ($this->index->getDefinitions() as $fqn => $def) {
$fqnStartsWithPrefix = substr($fqn, 0, $prefixLen) === $prefix;
if (
// Exclude methods, properties etc.
!$def->isMember
&& (
!$prefix
|| (
// Either not qualified, but a matching prefix with global fallback
($def->roamed && !$isQualified && $fqnStartsWithPrefix)
// Or not in a namespace or a fully qualified name or AND matching the prefix
|| ((!$namespaceNode || $isFullyQualified) && $fqnStartsWithPrefix)
// Or in a namespace, not fully qualified and matching the prefix + current namespace
|| (
$namespaceNode
&& !$isFullyQualified
&& substr($fqn, 0, $namespacedPrefixLen) === $namespacedPrefix
)
)
)
// Only suggest classes for `new`
&& (!isset($creation) || $def->canBeInstantiated)
) {
$item = CompletionItem::fromDefinition($def);
// Find the shortest name to reference the symbol
if ($namespaceNode && ($alias = array_search($fqn, $aliases, true)) !== false) {
// $alias is the name under which this definition is aliased in the current namespace
$item->insertText = $alias;
} else if ($namespaceNode && !($prefix && $isFullyQualified)) {
// Insert the global FQN with leading backslash
$item->insertText = '\\' . $fqn;
} else {
// Insert the FQN without leading backlash
$item->insertText = $fqn;
}
// Don't insert the parenthesis for functions
// TODO return a snippet and put the cursor inside
if (substr($item->insertText, -2) === '()') {
$item->insertText = substr($item->insertText, 0, -2);
}
$list->items[] = $item;
}
}
// If not a class instantiation, also suggest keywords
if (!isset($creation)) {
foreach (self::KEYWORDS as $keyword) {
if (substr($keyword, 0, $prefixLen) === $prefix) {
$item = new CompletionItem($keyword, CompletionItemKind::KEYWORD);
$item->insertText = $keyword;
$list->items[] = $item;
}
}
}
}
return $list;
}
/**
* Yields FQNs from an array along with the FQNs of all parent classes
*
* @param string[] $fqns
* @return Generator
*/
private function expandParentFqns(array $fqns) : Generator
{
foreach ($fqns as $fqn) {
yield $fqn;
$def = $this->index->getDefinition($fqn);
if ($def !== null) {
foreach ($def->getAncestorDefinitions($this->index) as $name => $def) {
yield $name;
}
}
}
}
/**
* Will walk the AST upwards until a function-like node is met
* and at each level walk all previous siblings and their children to search for definitions
* of that variable
*
* @param Node $node
* @param string $namePrefix Prefix to filter
* @return array <Node\Expr\Variable|Node\Param|Node\Expr\ClosureUse>
*/
private function suggestVariablesAtNode(Node $node, string $namePrefix = ''): array
{
$vars = [];
// Find variables in the node itself
// When getting completion in the middle of a function, $node will be the function node
// so we need to search it
foreach ($this->findVariableDefinitionsInNode($node, $namePrefix) as $var) {
// Only use the first definition
if (!isset($vars[$var->name])) {
$vars[$var->name] = $var;
}
}
// Walk the AST upwards until a scope boundary is met
$level = $node;
while ($level && !($level instanceof PhpParser\FunctionLike)) {
// Walk siblings before the node
$sibling = $level;
while ($sibling = $sibling->getPreviousSibling()) {
// Collect all variables inside the sibling node
foreach ($this->findVariableDefinitionsInNode($sibling, $namePrefix) as $var) {
$vars[$var->getName()] = $var;
}
}
$level = $level->parent;
}
// If the traversal ended because a function was met,
// also add its parameters and closure uses to the result list
if ($level && $level instanceof PhpParser\FunctionLike && $level->parameters !== null) {
foreach ($level->parameters->getValues() as $param) {
$paramName = $param->getName();
if (empty($namePrefix) || strpos($paramName, $namePrefix) !== false) {
$vars[$paramName] = $param;
}
}
if ($level instanceof Node\Expression\AnonymousFunctionCreationExpression && $level->anonymousFunctionUseClause !== null &&
$level->anonymousFunctionUseClause->useVariableNameList !== null) {
foreach ($level->anonymousFunctionUseClause->useVariableNameList->getValues() as $use) {
$useName = $use->getName();
if (empty($namePrefix) || strpos($useName, $namePrefix) !== false) {
$vars[$useName] = $use;
}
}
}
}
return array_values($vars);
}
/**
* Searches the subnodes of a node for variable assignments
*
* @param Node $node
* @param string $namePrefix Prefix to filter
* @return Node\Expression\Variable[]
*/
private function findVariableDefinitionsInNode(Node $node, string $namePrefix = ''): array
{
$vars = [];
// If the child node is a variable assignment, save it
$isAssignmentToVariable = function ($node) {
return $node instanceof Node\Expression\AssignmentExpression;
};
if ($this->isAssignmentToVariableWithPrefix($node, $namePrefix)) {
$vars[] = $node->leftOperand;
} else {
// Get all descendent variables, then filter to ones that start with $namePrefix.
// Avoiding closure usage in tight loop
foreach ($node->getDescendantNodes($isAssignmentToVariable) as $descendantNode) {
if ($this->isAssignmentToVariableWithPrefix($descendantNode, $namePrefix)) {
$vars[] = $descendantNode->leftOperand;
}
}
}
return $vars;
}
private function isAssignmentToVariableWithPrefix(Node $node, string $namePrefix): bool
{
return $node instanceof Node\Expression\AssignmentExpression
&& $node->leftOperand instanceof Node\Expression\Variable
&& ($namePrefix === '' || strpos($node->leftOperand->getName(), $namePrefix) !== false);
}
}