add automatic detection of the target php version

src/Command/Inspector/GetTraceCommand.php

@@ -27,6 +27,7 @@
 use PhpProfiler\Lib\Elf\Process\ProcessSymbolReaderException;
 use PhpProfiler\Lib\Elf\Tls\TlsFinderException;
 use PhpProfiler\Lib\PhpProcessReader\PhpGlobalsFinder;
+use PhpProfiler\Lib\PhpProcessReader\PhpVersionDetector;
 use PhpProfiler\Lib\Process\MemoryReader\MemoryReaderException;
 use PhpProfiler\Lib\PhpProcessReader\PhpMemoryReader\ExecutorGlobalsReader;
 use PhpProfiler\Lib\Process\ProcessStopper\ProcessStopper;
@@ -51,6 +52,7 @@ public function __construct(
         private ProcessStopper $process_stopper,
         private TargetProcessResolver $target_process_resolver,
         private RetryingLoopProvider $retrying_loop_provider,
+        private PhpVersionDetector $php_version_detector,
     ) {
         parent::__construct();
     }
@@ -85,6 +87,14 @@ public function execute(InputInterface $input, OutputInterface $output): int
 
         $process_specifier = $this->target_process_resolver->resolve($target_process_settings);
 
+        $version = $this->php_version_detector->tryDetection(
+            $process_specifier,
+            $target_php_settings
+        );
+        if (!is_null($version)) {
+            $target_php_settings = $target_php_settings->alterPhpVersion($version);
+        }
+
         // On targeting ZTS, it's possible that libpthread.so of the target process isn't yet loaded
         // at this point. In that case the TLS block can't be located, then the address of EG can't
         // be found also. So simply retrying the whole process of finding EG here.

src/Inspector/Daemon/Reader/Worker/PhpReaderTraceLoop.php

@@ -20,6 +20,7 @@
 use PhpProfiler\Inspector\Settings\TraceLoopSettings\TraceLoopSettings;
 use PhpProfiler\Lib\PhpProcessReader\PhpGlobalsFinder;
 use PhpProfiler\Lib\PhpProcessReader\PhpMemoryReader\ExecutorGlobalsReader;
+use PhpProfiler\Lib\PhpProcessReader\PhpVersionDetector;
 use PhpProfiler\Lib\Process\ProcessSpecifier;
 use PhpProfiler\Lib\Process\ProcessStopper\ProcessStopper;
 
@@ -33,6 +34,7 @@ public function __construct(
         private ExecutorGlobalsReader $executor_globals_reader,
         private ReaderLoopProvider $reader_loop_provider,
         private ProcessStopper $process_stopper,
+        private PhpVersionDetector $php_version_detector,
     ) {
     }
 
@@ -49,6 +51,13 @@ public function run(
         TargetPhpSettings $target_php_settings,
         GetTraceSettings $get_trace_settings
     ): Generator {
+        $version = $this->php_version_detector->tryDetection(
+            $process_specifier,
+            $target_php_settings
+        );
+        if (!is_null($version)) {
+            $target_php_settings = $target_php_settings->alterPhpVersion($version);
+        }
         $eg_address = $this->php_globals_finder->findExecutorGlobals($process_specifier, $target_php_settings);
 
         $loop = $this->reader_loop_provider->getMainLoop(

src/Lib/PhpProcessReader/PhpVersionDetector.php

@@ -0,0 +1,74 @@
+<?php
+
+/**
+ * This file is part of the sj-i/php-profiler package.
+ *
+ * (c) sji <sji@sj-i.dev>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace PhpProfiler\Lib\PhpProcessReader;
+
+use FFI\CPointer;
+use PhpProfiler\Inspector\Settings\TargetPhpSettings\TargetPhpSettings;
+use PhpProfiler\Lib\PhpInternals\ZendTypeCData;
+use PhpProfiler\Lib\PhpInternals\ZendTypeReader;
+use PhpProfiler\Lib\Process\MemoryReader\MemoryReaderInterface;
+use PhpProfiler\Lib\Process\ProcessSpecifier;
+
+final class PhpVersionDetector
+{
+    private const VERSION_STRING_CONVERTOR = [
+        '7.0' => ZendTypeReader::V70,
+        '7.1' => ZendTypeReader::V71,
+        '7.2' => ZendTypeReader::V72,
+        '7.3' => ZendTypeReader::V73,
+        '7.4' => ZendTypeReader::V74,
+        '8.0' => ZendTypeReader::V80,
+        '8.1' => ZendTypeReader::V81,
+    ];
+
+
+    public function __construct(
+        private PhpSymbolReaderCreator $php_symbol_reader_creator,
+        private ZendTypeReader $zend_type_reader,
+        private MemoryReaderInterface $memory_reader,
+    ) {
+    }
+
+    /** @return null|value-of<ZendTypeReader::ALL_SUPPORTED_VERSIONS> */
+    public function tryDetection(
+        ProcessSpecifier $process_specifier,
+        TargetPhpSettings $target_php_settings,
+    ): ?string {
+        try {
+            $php_symbol_reader = $this->php_symbol_reader_creator->create(
+                $process_specifier->pid,
+                $target_php_settings->getDelimitedPhpRegex(),
+                $target_php_settings->getDelimitedLibPthreadRegex(),
+                $target_php_settings->php_path,
+                $target_php_settings->libpthread_path,
+            );
+            $basic_functions_module = $php_symbol_reader->read('basic_functions_module')
+                ?? throw new \Exception();
+            /** @var ZendTypeCData<\FFI\PhpInternals\zend_module_entry> $module_entry */
+            $module_entry = $this->zend_type_reader->readAs('zend_module_entry', $basic_functions_module);
+            /** @var CPointer $version_string_pointer */
+            $version_string_pointer = \FFI::cast('long', $module_entry->typed->version)
+                ?? throw new \Exception();
+            $version_string_cdata = $this->memory_reader->read(
+                $process_specifier->pid,
+                $version_string_pointer->cdata,
+                3
+            );
+            $php_version = \FFI::string($version_string_cdata, 3);
+        } catch (\Throwable) {
+            return null;
+        }
+        return self::VERSION_STRING_CONVERTOR[$php_version] ?? null;
+    }
+}

tools/stubs/ffi/php.php

@@ -78,3 +78,8 @@ class zend_class_entry extends CData
 {
     public zend_string $name;
 }
+
+class zend_module_entry extends CData
+{
+    public int $version; // pointer
+}