Resolve function imports before dispatch and policy checks

phpunit/code/function-import-policy.php

@@ -0,0 +1,3 @@
+<?php
+use function exec as SAFE;
+function importedPolicyCall(): void { safe('not-executed'); }

phpunit/code/function-import-resolution.php

@@ -0,0 +1,27 @@
+<?php
+namespace {
+    function route(): string { return 'global'; }
+    function size(string $value): int { return 99; }
+}
+namespace AliasLibrary {
+    function route(): string { return 'import'; }
+    function callback_target(): string { return 'import-callback'; }
+}
+namespace AliasConsumer {
+    use function AliasLibrary\route as ROUTE;
+    use function AliasLibrary\route as GET_CALLED_CLASS;
+    use function strlen as SIZE;
+    use function AliasLibrary\route as extract;
+    use function AliasLibrary\{route as GROUPED};
+    use function AliasLibrary\callback_target as CALLBACK_TARGET;
+
+    function exercise(): void {
+        echo route(), ':', RoUtE(), ':', get_called_class(), ':', sIzE('abc'), ':', grouped(), ':', extract(), ':', \route(), "\n";
+        $size = sIzE(...);
+        $callback = cAlLbAcK_tArGeT(...);
+        $route = rOuTe(...);
+        $dynamic = $size;
+        echo $size('abcd'), ':', $callback(), ':', $route(), ':', $dynamic('abc'), "\n";
+    }
+}
+namespace { function main(): void { \AliasConsumer\exercise(); } }

phpunit/src/FunctionImportResolutionTest.php

@@ -0,0 +1,32 @@
+<?php
+
+use TypePhp\CompilerTest;
+
+final class FunctionImportResolutionTest extends BaseTest
+{
+    public function testImportedFunctionsTakePrecedenceRegardlessOfAliasCase(): void
+    {
+        global $translator;
+        $compiler = CompilerTest::create(TYPEPHP_ROOT_PATH);
+        $translator = $compiler;
+        $source = TYPEPHP_ROOT_PATH . '/phpunit/code/function-import-resolution.php';
+        $compiler->addFiles([$source]);
+        $compiler->prepareFile($source);
+        $code = file_get_contents($compiler->convertFile($source));
+        preg_match('/void php_aliasconsumer__exercise\(\) \{(.*?)\n\}/s', $code, $match);
+        self::assertCount(2, $match);
+        self::assertSame(5, substr_count($match[1], 'php_aliaslibrary__route('));
+        self::assertSame(1, substr_count($match[1], 'php_route('));
+        // The three first-class callables are materialized through
+        // Closure::fromCallable(); ordinary aliases above must stay direct.
+        self::assertSame(3, substr_count($match[1], 'php::call('));
+        self::assertStringNotContainsString('ZEND_STRL("sIzE")', $match[1]);
+        self::assertStringNotContainsString('ZEND_STRL("cAlLbAcK_tArGeT")', $match[1]);
+
+        $literalStrings = (new \ReflectionProperty($compiler, 'literalStrings'))->getValue($compiler);
+        self::assertArrayHasKey('strlen', $literalStrings);
+        self::assertArrayHasKey('AliasLibrary\\callback_target', $literalStrings);
+        self::assertArrayNotHasKey('sIzE', $literalStrings);
+        self::assertArrayNotHasKey('cAlLbAcK_tArGeT', $literalStrings);
+    }
+}

phpunit/src/NanoCapabilityPolicyTest.php

@@ -49,6 +49,34 @@ public function forgetBuildTimeFunction(string $name): void
 
 final class NanoCapabilityPolicyTest extends BaseTest
 {
+    public function testFunctionImportCannotBypassNanoPolicy(): void
+    {
+        $this->assertImportedFunctionRejected(false);
+    }
+
+    public function testFunctionImportCannotBypassWasiPolicy(): void
+    {
+        $this->assertImportedFunctionRejected(true);
+    }
+
+    private function assertImportedFunctionRejected(bool $wasi): void
+    {
+        global $translator;
+        $compiler = new NanoCapabilityPolicyCompiler(TYPEPHP_ROOT_PATH);
+        if ($wasi) {
+            $compiler->enableWasiForTest();
+        } else {
+            $compiler->enableNanoForTest();
+        }
+        $translator = $compiler;
+        $source = __DIR__ . '/../code/function-import-policy.php';
+        $compiler->addFiles([$source]);
+        $compiler->prepareFile($source);
+        $this->expectException(TestError::class);
+        $this->expectExceptionMessage('Function `exec` is not supported');
+        $compiler->convertFile($source);
+    }
+
     public function testRejectsForbiddenDirectCallMissingFromBuildTimePhp(): void
     {
         global $translator;

tests/compiler/namespace/function-import-resolution.phpt

@@ -0,0 +1,34 @@
+--TEST--
+Function imports are case-insensitive and take precedence over global functions
+--FILE--
+<?php
+namespace {
+    function route(): string { return 'global'; }
+    function size(string $value): int { return 99; }
+}
+namespace AliasLibrary {
+    function route(): string { return 'import'; }
+    function callback_target(): string { return 'import-callback'; }
+}
+namespace AliasConsumer {
+    use function AliasLibrary\route as ROUTE;
+    use function AliasLibrary\route as GET_CALLED_CLASS;
+    use function strlen as SIZE;
+    use function AliasLibrary\route as extract;
+    use function AliasLibrary\{route as GROUPED};
+    use function AliasLibrary\callback_target as CALLBACK_TARGET;
+
+    function exercise(): void {
+        echo route(), ':', RoUtE(), ':', get_called_class(), ':', sIzE('abc'), ':', grouped(), ':', extract(), ':', \route(), "\n";
+        $size = sIzE(...);
+        $callback = cAlLbAcK_tArGeT(...);
+        $route = rOuTe(...);
+        $dynamic = $size;
+        echo $size('abcd'), ':', $callback(), ':', $route(), ':', $dynamic('abc'), "\n";
+    }
+}
+namespace { function main(): void { \AliasConsumer\exercise(); } }
+?>
+--EXPECT--
+import:import:import:3:import:import:global
+4:import-callback:import:3