feat(compiler): implement independent import alias symbol domains

- Add useImportAliases property to track import aliases by type domain
- Implement registerUseImportAlias method with duplicate detection logic
- Update use declaration processing to utilize import alias registration
- Make class and function aliases case-insensitive while constants remain case-sensitive
- Add comprehensive test coverage for import alias domain isolation
- Include negative test cases for duplicate alias detection across domains
- Move AST name resolution earlier in preprocessing steps
- Add proper error handling for PHP parser errors during traversal

phpunit/code/namespace/import-alias-domains.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace ImportAliasDomains\First;
+
+use Vendor\Package\Route;
+use function Vendor\Package\dispatch as Route;
+use const Vendor\Package\ROUTE as Route;
+use const Vendor\Package\route as route;
+
+class Consumer {}
+
+namespace ImportAliasDomains\Second;
+
+// Import aliases are local to a namespace block.
+use Another\Package\Route;
+
+class Consumer {}

phpunit/src/ClassTest.php

@@ -2,6 +2,11 @@
 
 class ClassTest extends \BaseTest
 {
+    public function testImportAliasesUseIndependentPhpSymbolDomains(): void
+    {
+        $this->compile('namespace/import-alias-domains.php');
+    }
+
     public function testZendToArrayDeclarationCannotAcceptParameters(): void
     {
         $this->expectException(\TypePhp\Exception\TestError::class);

phpunit/src/NegativeCompatibilityTest.php

@@ -145,6 +145,54 @@ function main(): void
 PHP,
         ];
 
+        yield 'duplicate implicit class import' => [
+            'prepare',
+            'Cannot use Webman\\Route\\Route as Route because the name is already in use',
+            <<<'PHP'
+<?php
+namespace DuplicateImport;
+
+use support\annotation\route\Route;
+use Webman\Route\Route; // @diagnostic
+
+function main(): void
+{
+}
+PHP,
+        ];
+
+        yield 'duplicate class import alias is case insensitive' => [
+            'prepare',
+            'Cannot use Second\\Package\\Route as route because the name is already in use',
+            <<<'PHP'
+<?php
+namespace DuplicateImport;
+
+use First\Package\Route as Route;
+use Second\Package\Route as route; // @diagnostic
+
+function main(): void
+{
+}
+PHP,
+        ];
+
+        yield 'duplicate function import alias is case insensitive' => [
+            'prepare',
+            'Cannot use function Second\\Package\\dispatch as handler because the name is already in use',
+            <<<'PHP'
+<?php
+namespace DuplicateImport;
+
+use function First\Package\dispatch as Handler;
+use function Second\Package\dispatch as handler; // @diagnostic
+
+function main(): void
+{
+}
+PHP,
+        ];
+
         yield 'closure reference parameter' => [
             'convert',
             'Closure cannot use reference parameter',

src/CompilerBase.php

@@ -409,6 +409,8 @@ class CompilerBase implements PropertyAccessContext
     protected array $useAliases = [];
     protected array $useFunctions = [];
     protected array $useConstants = [];
+    /** @var array<int, array<string, string>> Import aliases separated by class/function/constant domain. */
+    protected array $useImportAliases = [];
 
     /**
      * 原始类名，不包含命名空间.
@@ -1033,6 +1035,7 @@ class CompilerBase implements PropertyAccessContext
         $this->useAliases = [];
         $this->useFunctions = [];
         $this->useConstants = [];
+        $this->useImportAliases = [];
         $this->namespace = '';
     }
 

src/Preprocessor.php

@@ -74,15 +74,15 @@ class Preprocessor extends CompilerBase
             }
             try {
                 $ast = $this->parser->parse($source);
+                $traverser = new NodeTraverser();
+                $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
+                $ast = $this->requireStatementList($traverser->traverse($ast));
             } catch (\PhpParser\Error) {
                 // prepareFile() owns the normal source diagnostic, including
                 // the filename and compiler formatting. Avoid reporting a
                 // syntax error twice from this declaration-only pass.
                 continue;
             }
-            $traverser = new NodeTraverser();
-            $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
-            $ast = $traverser->traverse($ast);
             $this->discoverNativeClassDeclarationsInAst($ast);
         }
     }
@@ -161,14 +161,14 @@ class Preprocessor extends CompilerBase
         foreach ($candidateSources as $source) {
             try {
                 $ast = $this->parser->parse($source);
+                $traverser = new NodeTraverser();
+                $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
+                $ast = $this->requireStatementList($traverser->traverse($ast));
             } catch (\PhpParser\Error) {
                 // prepareFile() has already emitted the authoritative syntax
                 // diagnostic. This pass must not report it a second time.
                 continue;
             }
-            $traverser = new NodeTraverser();
-            $traverser->addVisitor(new NameResolver(null, ['replaceNodes' => false]));
-            $ast = $traverser->traverse($ast);
             foreach ($discovery->discover($ast) as $slot) {
                 $this->registerNativeGlobalObject($slot['name'], $slot['class'], $slot['node']);
             }
@@ -307,7 +307,11 @@ class Preprocessor extends CompilerBase
                 $this->file,
                 fn (string $class, string $case): bool => $this->isDeclaredEnumCase($class, $case),
             ));
-            $stmts = $this->requireStatementList($traverser->traverse($ast));
+            try {
+                $stmts = $this->requireStatementList($traverser->traverse($ast));
+            } catch (\PhpParser\Error $error) {
+                $this->fatalPhpParserError($error);
+            }
             // Keep the resolved declaration AST until convert. Defaults and
             // constants are validated here, but their C++ expressions are not
             // generated until the complete symbol table is available.
@@ -344,6 +348,15 @@ class Preprocessor extends CompilerBase
         }
     }
 
+    protected function fatalPhpParserError(\PhpParser\Error $error): never
+    {
+        $location = $this->file;
+        if ($error->getStartLine() > 0) {
+            $location .= ':' . $error->getStartLine();
+        }
+        $this->error($error->getRawMessage() . ' in ' . $location);
+    }
+
     /**
      * Root parser output must remain a statement list after declaration
      * visitors have run. Validate that invariant before storing the AST.

src/Resolver/DeclarationSymbolTrait.php

@@ -76,24 +76,15 @@ trait DeclarationSymbolTrait
         foreach ($v2->uses as $use) {
             $id = $this->parseIdentifier($use->name);
             $type = $use->type !== Node\Stmt\Use_::TYPE_UNKNOWN ? $use->type : $v2->type;
+            $alias = $this->registerUseImportAlias($use, $type, $id);
             if ($type === Node\Stmt\Use_::TYPE_FUNCTION) {
-                $lastIndex = strrpos($id, '\\');
+                $this->useFunctions[$alias] = $id;
-                $fn = substr($id, $lastIndex + 1);
-                if ($use->alias) {
-                    $this->useFunctions[$use->alias->toString()] = $id;
-                } else {
-                    $this->useFunctions[$fn] = $id;
-                }
             } elseif ($type === Node\Stmt\Use_::TYPE_CONSTANT) {
                 $lastIndex = strrpos($id, '\\');
                 $cn = substr($id, $lastIndex + 1);
                 $ns = substr($id, 0, $lastIndex);
                 $fullName = $ns . '\\' . $cn;
-                if ($use->alias) {
+                $this->useConstants[$alias] = $fullName;
-                    $this->useConstants[$use->alias->toString()] = $fullName;
-                } else {
-                    $this->useConstants[$cn] = $fullName;
-                }
             } else {
                 $idLower = strtolower($id);
                 if ($idLower === 'native_types') {
@@ -107,7 +98,7 @@ trait DeclarationSymbolTrait
                         // Class and namespace import aliases are case-insensitive.
                         // An explicit alias replaces the implicit short name; it
                         // must not also make the target's final segment available.
-                        $this->useAliases[strtolower($use->alias->toString())] = $id;
+                        $this->useAliases[strtolower($alias)] = $id;
                     } else {
                         $this->useNamespaces[] = $id;
                     }
@@ -116,15 +107,38 @@ trait DeclarationSymbolTrait
         }
     }
 
+    private function registerUseImportAlias(Node\UseItem $use, int $type, string $id): string
+    {
+        $alias = $use->getAlias()->toString();
+        // PHP class and function names are case-insensitive, while constant
+        // aliases are case-sensitive. The three import kinds have independent
+        // symbol tables, so the same alias may be used once in each domain.
+        $key = $type === Node\Stmt\Use_::TYPE_CONSTANT ? $alias : strtolower($alias);
+        if (isset($this->useImportAliases[$type][$key])) {
+            $kind = match ($type) {
+                Node\Stmt\Use_::TYPE_FUNCTION => 'function ',
+                Node\Stmt\Use_::TYPE_CONSTANT => 'const ',
+                default => '',
+            };
+            $this->fatalError(
+                $use,
+                "Cannot use {$kind}{$id} as {$alias} because the name is already in use",
+            );
+        }
+        $this->useImportAliases[$type][$key] = $id;
+
+        return $alias;
+    }
+
     protected function parseGroupUse(Node\Stmt\GroupUse $node): void
     {
         $prefix = $node->prefix;
         $uses = [];
         foreach ($node->uses as $use) {
             $fullName = Node\Name::concat($prefix, $use->name);
-            $uses[] = new Node\UseItem($fullName, $use->alias, $use->type);
+            $uses[] = new Node\UseItem($fullName, $use->alias, $use->type, $use->getAttributes());
         }
-        $syntheticUse = new Node\Stmt\Use_($uses, $node->type);
+        $syntheticUse = new Node\Stmt\Use_($uses, $node->type, $node->getAttributes());
         $this->parseUse($syntheticUse);
     }