psalm/src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php

<?php
namespace Psalm\Internal\Analyzer\Statements;

use PhpParser;
use Psalm\Internal\Analyzer\FunctionLikeAnalyzer;
use Psalm\Internal\Analyzer\StatementsAnalyzer;
use Psalm\Internal\Analyzer\Statements\Expression\Fetch\VariableFetchAnalyzer;
use Psalm\CodeLocation;
use Psalm\Context;
use Psalm\Issue\InvalidGlobal;
use Psalm\IssueBuffer;
use function is_string;

class GlobalAnalyzer
{
    public static function analyze(
        StatementsAnalyzer $statements_analyzer,
        PhpParser\Node\Stmt\Global_ $stmt,
        Context $context,
        ?Context $global_context
    ) : void {
        if (!$context->collect_initializations && !$global_context) {
            if (IssueBuffer::accepts(
                new InvalidGlobal(
                    'Cannot use global scope here',
                    new CodeLocation($statements_analyzer, $stmt)
                ),
                $statements_analyzer->getSource()->getSuppressedIssues()
            )) {
                // fall through
            }
        }

        $source = $statements_analyzer->getSource();
        $function_storage = $source instanceof FunctionLikeAnalyzer
            ? $source->getFunctionLikeStorage($statements_analyzer)
            : null;

        foreach ($stmt->vars as $var) {
            if ($var instanceof PhpParser\Node\Expr\Variable) {
                if (is_string($var->name)) {
                    $var_id = '$' . $var->name;

                    if ($var->name === 'argv' || $var->name === 'argc') {
                        $context->vars_in_scope[$var_id] = VariableFetchAnalyzer::getGlobalType($var_id);
                    } elseif (isset($function_storage->global_types[$var_id])) {
                        $context->vars_in_scope[$var_id] = clone $function_storage->global_types[$var_id];
                        $context->vars_possibly_in_scope[$var_id] = true;
                    } else {
                        $context->vars_in_scope[$var_id] =
                            $global_context && $global_context->hasVariable($var_id)
                                ? clone $global_context->vars_in_scope[$var_id]
                                : VariableFetchAnalyzer::getGlobalType($var_id);

                        $context->vars_possibly_in_scope[$var_id] = true;

                        $context->byref_constraints[$var_id] = new \Psalm\Internal\ReferenceConstraint();
                    }
                }
            }
        }
    }
}