feat: add frankenphp_log_attrs() as a PHP function

The CGO method allow to log a php message while binding an array of random
type as slog.Attr.

Author: raphaelcoeffic

frankenphp.c

@@ -549,6 +549,28 @@ PHP_FUNCTION(mercure_publish) {
   RETURN_THROWS();
 }
 
+PHP_FUNCTION(frankenphp_log) {
+  char *message = NULL;
+  size_t message_len = 0;
+  zend_long level = 0;
+  zval *context = NULL;
+
+  ZEND_PARSE_PARAMETERS_START(2, 3)
+    Z_PARAM_STRING(message, message_len)
+    Z_PARAM_LONG(level)
+    Z_PARAM_OPTIONAL
+    Z_PARAM_ARRAY(context)
+  ZEND_PARSE_PARAMETERS_END();
+
+  char * ret = NULL;
+  ret = go_log_attrs(thread_index, message, message_len, (int)level, context);
+  if (ret != NULL) {
+    zend_throw_exception(spl_ce_RuntimeException, ret, 0);
+    // free(ret); // NOTE: is the string copied by zend_throw ??
+    RETURN_THROWS();
+  }
+}
+
 PHP_MINIT_FUNCTION(frankenphp) {
   zend_function *func;
 

frankenphp.go

@@ -693,6 +693,81 @@ func go_log(threadIndex C.uintptr_t, message *C.char, level C.int) {
 	}
 }
 
+// go_log_attrs is a cgo-exported bridge between PHP and the Go slog logger.
+//
+// It is called from C/PHP and must not panic. All errors are reported by
+// returning a C-allocated error string; on success it returns NULL.
+//
+// Parameters:
+//
+// threadIndex:
+//   - Index into the phpThreads table, used to retrieve the Go context for
+//     the current PHP request/thread.
+//
+// message:
+//   - Pointer to a C string containing the log message bytes. The memory
+//     is owned by the caller and must NOT be freed by Go.
+//
+// len:
+//   - Length of the message, in bytes, as seen from C (not including the
+//     terminating NUL). This is passed to C.GoStringN to build the Go string.
+//
+// level:
+//   - Numeric log level compatible with slog.Level values. It is cast to
+//     slog.Level inside this function.
+//
+// cattrs:
+//   - Pointer to a PHP zval representing an associative array of attributes,
+//     or NULL. When non-NULL, it is converted to map[string]any via GoMap[any]
+//     and then mapped to slog.Attr values (using slog.Any under the hood).
+//
+// Return value:
+//
+// On success:
+//   - Returns NULL and the message is logged (if the logger is enabled at
+//     the given level).
+//
+// On error:
+//   - Returns a non-NULL *C.char pointing to a NUL-terminated error message
+//     allocated with C.CString. The caller is responsible for releasing
+//     this memory.
+//
+//export go_log_attrs
+func go_log_attrs(threadIndex C.uintptr_t, message *C.char, len C.int, level C.int, cattrs *C.zval) *C.char {
+	var attrs map[string]any
+
+	if cattrs == nil {
+		attrs = nil
+	} else {
+		var err error
+		if attrs, err = GoMap[any](unsafe.Pointer(cattrs)); err != nil {
+			// NOTE: return value is already formatted for a PHP exception message.
+			return C.CString("Failed to log message: converting attrs: " + err.Error())
+		}
+	}
+
+	m := C.GoStringN(message, len)
+	lvl := slog.Level(level)
+
+	ctx := phpThreads[threadIndex].context()
+
+	if globalLogger.Enabled(ctx, lvl) {
+		globalLogger.LogAttrs(ctx, lvl, m, mapToAttr(attrs)...)
+	}
+
+	return nil
+}
+
+func mapToAttr(input map[string]any) []slog.Attr {
+	out := make([]slog.Attr, 0, len(input))
+
+	for key, val := range input {
+		out = append(out, slog.Any(key, val))
+	}
+
+	return out
+}
+
 //export go_is_context_done
 func go_is_context_done(threadIndex C.uintptr_t) C.bool {
 	return C.bool(phpThreads[threadIndex].frankenPHPContext().isDone)

frankenphp.stub.php

@@ -36,3 +36,9 @@ function apache_response_headers(): array|bool {}
  * @param string|string[] $topics
  */
 function mercure_publish(string|array $topics, string $data = '', bool $private = false, ?string $id = null, ?string $type = null, ?int $retry = null): string {}
+
+/**
+ * @param int $level The importance or severity of a log event. The higher the level, the more important or severe the event. Common levels are -4 for debug, 0 for info, 4 for warn, and 8 for error. For more details, see: https://pkg.go.dev/log/slog#Level
+ * array<string, any> $context Values of the array will be converted to the corresponding Go type (if supported by FrankenPHP) and added to the context of the structured logs using https://pkg.go.dev/log/slog#Attr
+ */
+function frankenphp_log(string $message, int $level = 0, array $context = []): void {}

frankenphp_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: cd534a8394f535a600bf45a333955d23b5154756 */
+ * Stub hash: 28aa97e2c6102b3e51059dbd001ac65679f0bfda */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_frankenphp_handle_request, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, callback, IS_CALLABLE, 0)
@@ -35,25 +35,31 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mercure_publish, 0, 1, IS_STRING
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, retry, IS_LONG, 1, "null")
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_frankenphp_log, 0, 1, IS_VOID, 0)
+	ZEND_ARG_TYPE_INFO(0, message, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, level, IS_LONG, 0, "0")
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, context, IS_ARRAY, 0, "[]")
+ZEND_END_ARG_INFO()
 
 ZEND_FUNCTION(frankenphp_handle_request);
 ZEND_FUNCTION(headers_send);
 ZEND_FUNCTION(frankenphp_finish_request);
 ZEND_FUNCTION(frankenphp_request_headers);
 ZEND_FUNCTION(frankenphp_response_headers);
 ZEND_FUNCTION(mercure_publish);
-
+ZEND_FUNCTION(frankenphp_log);
 
 static const zend_function_entry ext_functions[] = {
 	ZEND_FE(frankenphp_handle_request, arginfo_frankenphp_handle_request)
 	ZEND_FE(headers_send, arginfo_headers_send)
 	ZEND_FE(frankenphp_finish_request, arginfo_frankenphp_finish_request)
-	ZEND_FALIAS(fastcgi_finish_request, frankenphp_finish_request, arginfo_fastcgi_finish_request)
+	ZEND_RAW_FENTRY("fastcgi_finish_request", zif_frankenphp_finish_request, arginfo_fastcgi_finish_request, 0, NULL, NULL)
 	ZEND_FE(frankenphp_request_headers, arginfo_frankenphp_request_headers)
-	ZEND_FALIAS(apache_request_headers, frankenphp_request_headers, arginfo_apache_request_headers)
-	ZEND_FALIAS(getallheaders, frankenphp_request_headers, arginfo_getallheaders)
+	ZEND_RAW_FENTRY("apache_request_headers", zif_frankenphp_request_headers, arginfo_apache_request_headers, 0, NULL, NULL)
+	ZEND_RAW_FENTRY("getallheaders", zif_frankenphp_request_headers, arginfo_getallheaders, 0, NULL, NULL)
 	ZEND_FE(frankenphp_response_headers, arginfo_frankenphp_response_headers)
-	ZEND_FALIAS(apache_response_headers, frankenphp_response_headers, arginfo_apache_response_headers)
+	ZEND_RAW_FENTRY("apache_response_headers", zif_frankenphp_response_headers, arginfo_apache_response_headers, 0, NULL, NULL)
 	ZEND_FE(mercure_publish, arginfo_mercure_publish)
+	ZEND_FE(frankenphp_log, arginfo_frankenphp_log)
 	ZEND_FE_END
 };

frankenphp_test.go

@@ -1058,7 +1058,34 @@ func FuzzRequest(f *testing.F) {
 			// Headers should always be present even if empty
 			assert.Contains(t, body, fmt.Sprintf("[CONTENT_TYPE] => %s", fuzzedString))
 			assert.Contains(t, body, fmt.Sprintf("[HTTP_FUZZED] => %s", fuzzedString))
-
 		}, &testOptions{workerScript: "request-headers.php"})
 	})
 }
+
+func TestFrankenPHPLog(t *testing.T) {
+	var buf bytes.Buffer
+	handler := slog.NewTextHandler(&buf, &slog.HandlerOptions{Level: slog.LevelDebug})
+	logger := slog.New(handler)
+
+	runTest(t, func(handler func(http.ResponseWriter, *http.Request), _ *httptest.Server, _ int) {
+		body, _ := testGet("http://example.com/log_to_slog.php", handler, t)
+		assert.Empty(t, body)
+	}, &testOptions{
+		logger:             logger,
+		nbParallelRequests: 1,
+		nbWorkers:          1,
+	})
+
+	logOutput := buf.String()
+
+	t.Logf("captured log output: %s", logOutput)
+
+	for level, needle := range map[string]string{
+		"debug attrs": `level=DEBUG msg="some debug message" "key int"=1`,
+		"info attrs":  `level=INFO msg="some info message" "key string"=string`,
+		"warn attrs":  `level=WARN msg="some warn message"`,
+		"error attrs": `level=ERROR msg="some error message" err="[a v]"`,
+	} {
+		assert.Containsf(t, logOutput, needle, "should contains %q log", level)
+	}
+}

testdata/log_to_slog.php

@@ -0,0 +1,23 @@
+<?php
+
+// NOTE: use CGO frankenphp_log method.
+// The message and it's optional arguments are expected to be logged by go' std slog system.
+// The log level should be respected out of the box by the std' slog.
+//
+// ac[0] expect the log message as string
+// ac[1] expect the slog.Level, from -8 to +8
+// ac[2] is an optional php map, which will be converted to a []slog.Attr
+
+frankenphp_log("some debug message", -4, [
+    "key int"    => 1,
+]);
+
+frankenphp_log("some info message", 0, [
+    "key string" => "string",
+]);
+
+frankenphp_log("some warn message", 4);
+
+frankenphp_log("some error message", 8, [
+    "err" => ["a", "v"],
+]);