feat: thread context from breakpad on macos (#1083)

* feat: provide the thread-context to the [on_crash|before_send]-hooks on macOS from the breakpad backend.

* Get rid of remaining static functions with `sentry__` prefix in the breakpad backend.

* update `breakpad` submodule to our fork's `handler` branch

Author: supervacuus

CHANGELOG.md

@@ -5,6 +5,11 @@
 **Features**:
 
 - Android NDK: Add `.loadNativeLibraries()` method to allow pre-loading .so files ([#1082](https://github.com/getsentry/sentry-native/pull/1082))
+- Fill the `ucontext_t` field in the `sentry_ucontext_t` `[on_crash|before_send]`-hook parameter on `macOS` from the `breakpad` backend. ([#1083](https://github.com/getsentry/sentry-native/pull/1083), [breakpad#39](https://github.com/getsentry/breakpad/pull/39))
+
+**Thank you**:
+
+[saf-e](https://github.com/saf-e)
 
 ## 0.7.13
 

CMakeLists.txt

@@ -479,6 +479,7 @@ if(SENTRY_BACKEND_CRASHPAD)
 elseif(SENTRY_BACKEND_BREAKPAD)
 	option(SENTRY_BREAKPAD_SYSTEM "Use system breakpad" OFF)
 	if(SENTRY_BREAKPAD_SYSTEM)
+		target_compile_definitions(sentry PRIVATE SENTRY_BREAKPAD_SYSTEM)
 		# system breakpad is using pkg-config, see `external/breakpad/breakpad-client.pc.in`
 		find_package(PkgConfig REQUIRED)
 		pkg_check_modules(BREAKPAD REQUIRED IMPORTED_TARGET breakpad-client)

external/CMakeLists.txt

@@ -128,6 +128,7 @@ add_library(breakpad_client STATIC)
 set_property(TARGET breakpad_client PROPERTY CXX_STANDARD 17)
 set_property(TARGET breakpad_client PROPERTY CXX_STANDARD_REQUIRED On)
 target_sources(breakpad_client PRIVATE ${BREAKPAD_SOURCES_COMMON})
+target_compile_definitions(breakpad_client PRIVATE SENTRY_BACKEND_BREAKPAD)
 
 if(LINUX OR ANDROID)
     target_sources(breakpad_client PRIVATE ${BREAKPAD_SOURCES_COMMON_LINUX} ${BREAKPAD_SOURCES_CLIENT_LINUX})

external/breakpad

@@ -29,6 +29,7 @@ extern "C" {
 #elif defined(SENTRY_PLATFORM_MACOS)
 #    include "client/mac/handler/exception_handler.h"
 #    include <sys/sysctl.h>
+#    include <unistd.h>
 #elif defined(SENTRY_PLATFORM_IOS)
 #    include "client/ios/exception_handler_no_mach.h"
 #else
@@ -41,18 +42,24 @@ extern "C" {
 
 #ifdef SENTRY_PLATFORM_WINDOWS
 static bool
-sentry__breakpad_backend_callback(const wchar_t *breakpad_dump_path,
+breakpad_backend_callback(const wchar_t *breakpad_dump_path,
     const wchar_t *minidump_id, void *UNUSED(context),
     EXCEPTION_POINTERS *exinfo, MDRawAssertionInfo *UNUSED(assertion),
     bool succeeded)
 #elif defined(SENTRY_PLATFORM_DARWIN)
+#    ifdef SENTRY_BREAKPAD_SYSTEM
 static bool
-sentry__breakpad_backend_callback(const char *breakpad_dump_path,
+breakpad_backend_callback(const char *breakpad_dump_path,
     const char *minidump_id, void *UNUSED(context), bool succeeded)
+#    else
+static bool
+breakpad_backend_callback(const char *breakpad_dump_path,
+    const char *minidump_id, void *UNUSED(context),
+    breakpad_ucontext_t *user_context, bool succeeded)
+#    endif
 #else
 static bool
-sentry__breakpad_backend_callback(
-    const google_breakpad::MinidumpDescriptor &descriptor,
+breakpad_backend_callback(const google_breakpad::MinidumpDescriptor &descriptor,
     void *UNUSED(context), bool succeeded)
 #endif
 {
@@ -106,6 +113,12 @@ sentry__breakpad_backend_callback(
         if (options->on_crash_func) {
             sentry_ucontext_t *uctx = nullptr;
 
+#if defined(SENTRY_PLATFORM_DARWIN) && !defined(SENTRY_BREAKPAD_SYSTEM)
+            sentry_ucontext_t uctx_data;
+            uctx_data.user_context = user_context;
+            uctx = &uctx_data;
+#endif
+
 #ifdef SENTRY_PLATFORM_WINDOWS
             sentry_ucontext_t uctx_data;
             uctx_data.exception_ptrs = *exinfo;
@@ -206,49 +219,48 @@ IsDebuggerActive()
 #endif
 
 static int
-sentry__breakpad_backend_startup(
+breakpad_backend_startup(
     sentry_backend_t *backend, const sentry_options_t *options)
 {
     sentry_path_t *current_run_folder = options->run->run_path;
 
 #ifdef SENTRY_PLATFORM_WINDOWS
     sentry__reserve_thread_stack();
     backend->data = new google_breakpad::ExceptionHandler(
-        current_run_folder->path, NULL, sentry__breakpad_backend_callback, NULL,
+        current_run_folder->path, NULL, breakpad_backend_callback, NULL,
         google_breakpad::ExceptionHandler::HANDLER_EXCEPTION);
 #elif defined(SENTRY_PLATFORM_MACOS)
     // If process is being debugged and there are breakpoints set it will cause
     // task_set_exception_ports to crash the whole process and debugger
-    backend->data
-        = new google_breakpad::ExceptionHandler(current_run_folder->path, NULL,
-            sentry__breakpad_backend_callback, NULL, !IsDebuggerActive(), NULL);
+    backend->data = new google_breakpad::ExceptionHandler(
+        current_run_folder->path, nullptr, breakpad_backend_callback, nullptr,
+        !IsDebuggerActive(), nullptr);
 #elif defined(SENTRY_PLATFORM_IOS)
     backend->data
-        = new google_breakpad::ExceptionHandler(current_run_folder->path, NULL,
-            sentry__breakpad_backend_callback, NULL, true, NULL);
+        = new google_breakpad::ExceptionHandler(current_run_folder->path,
+            nullptr, breakpad_backend_callback, nullptr, true, nullptr);
 #else
     google_breakpad::MinidumpDescriptor descriptor(current_run_folder->path);
     backend->data = new google_breakpad::ExceptionHandler(
-        descriptor, NULL, sentry__breakpad_backend_callback, NULL, true, -1);
+        descriptor, nullptr, breakpad_backend_callback, nullptr, true, -1);
 #endif
-    return backend->data == NULL;
+    return backend->data == nullptr;
 }
 
 static void
-sentry__breakpad_backend_shutdown(sentry_backend_t *backend)
+breakpad_backend_shutdown(sentry_backend_t *backend)
 {
-    google_breakpad::ExceptionHandler *eh
-        = (google_breakpad::ExceptionHandler *)backend->data;
-    backend->data = NULL;
+    const auto *eh
+        = static_cast<google_breakpad::ExceptionHandler *>(backend->data);
+    backend->data = nullptr;
     delete eh;
 }
 
 static void
-sentry__breakpad_backend_except(
+breakpad_backend_except(
     sentry_backend_t *backend, const sentry_ucontext_t *context)
 {
-    google_breakpad::ExceptionHandler *eh
-        = (google_breakpad::ExceptionHandler *)backend->data;
+    auto *eh = static_cast<google_breakpad::ExceptionHandler *>(backend->data);
 
 #ifdef SENTRY_PLATFORM_WINDOWS
     eh->WriteMinidumpForException(
@@ -274,15 +286,15 @@ extern "C" {
 sentry_backend_t *
 sentry__backend_new(void)
 {
-    sentry_backend_t *backend = SENTRY_MAKE(sentry_backend_t);
+    auto *backend = SENTRY_MAKE(sentry_backend_t);
     if (!backend) {
-        return NULL;
+        return nullptr;
     }
     memset(backend, 0, sizeof(sentry_backend_t));
 
-    backend->startup_func = sentry__breakpad_backend_startup;
-    backend->shutdown_func = sentry__breakpad_backend_shutdown;
-    backend->except_func = sentry__breakpad_backend_except;
+    backend->startup_func = breakpad_backend_startup;
+    backend->shutdown_func = breakpad_backend_shutdown;
+    backend->except_func = breakpad_backend_except;
 
     return backend;
 }