Forbid direct access to static members on traits

[nikic]

This forbids directly accessing static properties and static methods on traits. Trait members in general can only be used through the class in which the trait was used, but due to an implementation oversight access to static members was still allowed. This change remedies this.

[nikic]

Usages found in open-source projects:

/home/nikic/package-analysis/sources/drupal/core/modules/simpletest/src/WebTestBase.php:706
    DeprecationListenerTrait::getSkippedDeprecations()
/home/nikic/package-analysis/sources/drupal/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulRevPub.php:63
    EntityPublishedTrait::publishedBaseFieldDefinitions($entity_type)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/AST/ContextNode.php:2434
    ConditionVisitorUtil::getFunctionName($node)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Language/Element/FunctionTrait.php:1083
    FunctionTrait::addParamsToScopeOfFunctionOrMethod($this->getContext(), $code_base, $this, $comment)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Analysis/ConditionVisitor/NotHasTypeCondition.php:48
    ConditionVisitorUtil::excludeMatchingTypes($code_base, $variable->getUnionType(), $this->type)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Analysis/PreOrderAnalysisVisitor.php:169
    Analyzable::ensureDidAnnotate($node)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Analysis/PreOrderAnalysisVisitor.php:272
    Analyzable::ensureDidAnnotate($node)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Analysis/PreOrderAnalysisVisitor.php:404
    Analyzable::ensureDidAnnotate($node)
/home/nikic/package-analysis/sources/phan/phan/src/Phan/Analysis/PreOrderAnalysisVisitor.php:543
    Analyzable::ensureDidAnnotate($node)
/home/nikic/package-analysis/sources/google/gax/src/Testing/MockStubTrait.php:145
    MockStubTrait::stripStatusFromResponses($this->responses)
/home/nikic/package-analysis/sources/google/gax/src/Testing/MockStubTrait.php:174
    MockStubTrait::stripStatusFromResponses($this->responses)
/home/nikic/package-analysis/sources/drush/drush/examples/Commands/SyncViaHttpCommands.php:64
    ExecTrait::programExists('wget')
/home/nikic/package-analysis/sources/encore/laravel-admin/src/Grid/Tools/QuickSearch.php:22
    HasQuickSearch::$searchKey
/home/nikic/package-analysis/sources/encore/laravel-admin/src/Grid/Tools/QuickSearch.php:26
    HasQuickSearch::$searchKey
/home/nikic/package-analysis/sources/encore/laravel-admin/src/Grid/Tools/QuickSearch.php:27
    HasQuickSearch::$searchKey
/home/nikic/package-analysis/sources/elasticsearch/elasticsearch/src/Elasticsearch/Namespaces/IndicesNamespace.php:50
    BooleanRequestWrapper::performRequest($endpoint, $this->transport)
/home/nikic/package-analysis/sources/elasticsearch/elasticsearch/src/Elasticsearch/Namespaces/IndicesNamespace.php:480
    BooleanRequestWrapper::performRequest($endpoint, $this->transport)
/home/nikic/package-analysis/sources/elasticsearch/elasticsearch/src/Elasticsearch/Namespaces/IndicesNamespace.php:685
    BooleanRequestWrapper::performRequest($endpoint, $this->transport)
/home/nikic/package-analysis/sources/elasticsearch/elasticsearch/src/Elasticsearch/Namespaces/IndicesNamespace.php:960
    BooleanRequestWrapper::performRequest($endpoint, $this->transport)
/home/nikic/package-analysis/sources/elasticsearch/elasticsearch/src/Elasticsearch/Client.php:561
    BooleanRequestWrapper::performRequest($endpoint, $this->transport)

[nikic]

Heads up @z-song on the use of the trait member HasQuickSearch::$searchKey in https://github.com/z-song/laravel-admin/blob/335655b30632858826bea896cca4056194d03879/src/Grid/Tools/QuickSearch.php#L37-L51. Is it possible to avoid accessing this directly on a trait?

[villfa]

These 2 lines should be in their own try/catch block, otherwise the case covered by the 2nd line would not be tested.

[Ocramius]

This looks sensible - not sure whether there are real-world necessary use-cases for it, but they can be replaced via abstract class using the trait, I suppose.

[dstogov]

I think, it's better to pass this change through RFC process.
It's definitely going to affect some projects, but fixes are going to be trivial.

[krakjoe]

I think an RFC for 8 makes sense

[kocsismate]

@nikic Do you still want to pursue this RFC for PHP 8.0? Or is it not that important to have in PHP 8.0?

[nikic]

A deprecation for this is part of https://wiki.php.net/rfc/deprecations_php_8_1. Closing this outright removal.