sentry plugin: bundle crashpad_handler

Author: ardera

CMakeLists.txt

@@ -75,7 +75,8 @@ set(FILESYSTEM_LAYOUTS default meta-flutter)
 set(FILESYSTEM_LAYOUT "default" CACHE STRING "Where to look for the icudtl.dat, app.so/libapp.so, flutter asset bundle.")
 set_property(CACHE FILESYSTEM_LAYOUT PROPERTY STRINGS ${FILESYSTEM_LAYOUTS})
 
-set(SENTRY_BACKEND "inproc" CACHE STRING "What sentry backend to use, when the sentry plugin is built. Allowed values are inproc, crashpad and breakpad. Crashpad requires the built crashpad_handler executable that's to be present next to flutter-pi.")
+set(SENTRY_BACKEND "inproc" CACHE STRING "What sentry backend to use, when the sentry plugin is built. Allowed values are inproc, crashpad and breakpad.")
+option(SENTRY_PLUGIN_BUNDLE_CRASHPAD_HANDLER "Bundle the crashpad_handler with the flutter-pi executable." ON)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
@@ -352,13 +353,25 @@ if (BUILD_CHARSET_CONVERTER_PLUGIN)
 endif()
 
 # Sentry Plugin
+set(HAVE_BUNDLED_CRASHPAD_HANDLER OFF)
 if (BUILD_SENTRY_PLUGIN)
   add_subdirectory(third_party/sentry-native)
 
   target_sources(flutterpi_module PRIVATE src/plugins/sentry/sentry.c)
-  target_link_libraries(flutterpi_module PUBLIC sentry)
+  target_link_libraries(flutterpi_module PUBLIC sentry::sentry)
+
+  if (SENTRY_PLUGIN_BUNDLE_CRASHPAD_HANDLER)
+    set(HAVE_BUNDLED_CRASHPAD_HANDLER ON)
+  
+    target_sources(flutterpi_module PRIVATE src/crashpad_handler_trampoline.cc)
+    # link against the same libraries the crashpad_handler uses
+    
+    get_target_property(handler_deps crashpad_handler INTERFACE_LINK_LIBRARIES)
+    target_link_libraries(flutterpi_module PUBLIC ${handler_deps})
+  endif()
 endif()
 message(STATUS "Sentry plugin: ${BUILD_SENTRY_PLUGIN}")
+message(STATUS "Bundle crashpad_handler: ${HAVE_BUNDLED_CRASHPAD_HANDLER}")
 
 # Needed so dart VM can actually resolve symbols in the same
 # executable. (For dart:ffi DynamicLibrary.executable / DynamicLibrary.process)

config.h.in

@@ -25,5 +25,6 @@
 #cmakedefine VULKAN_DEBUG
 #cmakedefine ENABLE_MTRACE
 #cmakedefine ENABLE_ASAN
+#cmakedefine HAVE_BUNDLED_CRASHPAD_HANDLER
 
 #endif

src/crashpad_handler_trampoline.cc

@@ -0,0 +1,15 @@
+#include "config.h"
+
+#ifndef HAVE_BUNDLED_CRASHPAD_HANDLER
+#error "This file should only be built when using the bundled crashpad handler"
+#endif
+
+#include "handler/handler_main.h"
+
+extern "C" {
+
+int crashpad_handler_main(int argc, char **argv) {
+    return crashpad::HandlerMain(argc, argv, nullptr);
+}
+
+}

src/main.c

@@ -1,5 +1,30 @@
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "config.h"
+
 int flutterpi_app_main(int argc, char **argv);
+int crashpad_handler_main(int argc, char **argv);
+
+#ifdef HAVE_BUNDLED_CRASHPAD_HANDLER
+static bool running_in_crashpad_mode(int argc, char **argv) {
+    for (int i = 0; i < argc; i++) {
+        if (strcmp(argv[i], "--attachment=FlutterpiCrashpadHandlerMode") == 0) {
+            return true;
+        }
+    }
+
+    return false;
+}
+#endif
 
 int main(int argc, char **argv) {
+#ifdef HAVE_BUNDLED_CRASHPAD_HANDLER
+    if (running_in_crashpad_mode(argc, argv)) {
+        return crashpad_handler_main(argc, argv);
+    }
+#endif
+
     return flutterpi_app_main(argc, argv);
 }

src/plugins/sentry/sentry.c

@@ -1,3 +1,6 @@
+#define _POSIX_C_SOURCE 200809L
+#include <unistd.h>
+
 #include <sentry.h>
 
 #include "flutter-pi.h"
@@ -18,11 +21,34 @@ struct sentry_plugin {
     bool sentry_initialized;
 };
 
+static int sentry_configure_bundled_crashpad_handler(sentry_options_t *options) {
+    char *path = malloc(PATH_MAX);
+    if (path == NULL) {
+        return ENOMEM;
+    }
+
+    ssize_t n_read = readlink("/proc/self/exe", path, PATH_MAX);
+    if (n_read == -1) {
+        free(path);
+        return errno;
+    }
+
+    sentry_options_set_handler_path_n(options, path, n_read);
+
+    free(path);
+
+    sentry_options_add_attachment(options, "FlutterpiCrashpadHandlerMode");
+
+    return 0;
+}
+
 static void on_init_native_sdk(
     struct sentry_plugin *plugin,
     const struct raw_std_value *arg,
     const FlutterPlatformMessageResponseHandle *responsehandle
 ) {
+    int ok;
+
     (void) plugin;
     (void) arg;
     (void) responsehandle;
@@ -118,7 +144,15 @@ static void on_init_native_sdk(
         sentry_options_get_auto_session_tracking(options) ? "true" : "false"
     );
 
-    int ok = sentry_init(options);
+#ifdef HAVE_BUNDLED_CRASHPAD_HANDLER
+    ok = sentry_configure_bundled_crashpad_handler(options);
+    if (!ok) {
+        platch_respond_error_std(responsehandle, "1", "Failed to configure bundled Crashpad handler.", &STDNULL);
+        return;
+    }
+#endif
+
+    ok = sentry_init(options);
     if (ok != 0) {
         platch_respond_error_std(responsehandle, "1", "Failed to initialize Sentry.", &STDNULL);
         return;