From 6b9b05a89badb31c839c5b233f268bbb4c7ac01f Mon Sep 17 00:00:00 2001
From: cammm <81903+cammm@users.noreply.github.com>
Date: Thu, 26 Mar 2020 19:03:58 -0700
Subject: [PATCH 1/5] New handle exception API

Allows manually triggering of the backend given a completed ucontext
---
 include/sentry.h                         |  6 ++++++
 src/backends/sentry_backend_breakpad.cpp |  9 +++++++++
 src/backends/sentry_backend_crashpad.cpp |  9 +++++++++
 src/backends/sentry_backend_inproc.c     | 11 +++++++++--
 src/sentry_backend.h                     |  2 ++
 src/sentry_core.c                        |  8 ++++++++
 6 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/include/sentry.h b/include/sentry.h
index c52d28d2d..f7799ce9d 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -320,6 +320,7 @@ typedef struct sentry_ucontext_s {
 #ifdef _WIN32
     EXCEPTION_POINTERS exception_ptrs;
 #else
+    int signum;
     siginfo_t *siginfo;
     ucontext_t *user_context;
 #endif
@@ -650,6 +651,11 @@ SENTRY_API sentry_user_consent_t sentry_user_consent_get(void);
  */
 SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
 
+/*
+ * Captures an exception to be handled by the backend.
+ */
+SENTRY_API void sentry_handle_exception(sentry_ucontext_t *context);
+
 /*
  * Adds the breadcrumb to be sent in case of an event.
  */
diff --git a/src/backends/sentry_backend_breakpad.cpp b/src/backends/sentry_backend_breakpad.cpp
index 9091c05ec..e536a8150 100644
--- a/src/backends/sentry_backend_breakpad.cpp
+++ b/src/backends/sentry_backend_breakpad.cpp
@@ -146,6 +146,14 @@ sentry__breakpad_backend_shutdown(sentry_backend_t *backend)
     delete eh;
 }
 
+static void sentry__breakpad_backend_except(
+    sentry_backend_t *UNUSED(backend), sentry_ucontext_t *context)
+{
+    google_breakpad::ExceptionHandler *eh
+        = (google_breakpad::ExceptionHandler *)backend->data;
+    eh->HandleSignal(context->signum, context->siginfo, context->user_context);
+}
+
 extern "C" {
 
 sentry_backend_t *
@@ -158,6 +166,7 @@ sentry__backend_new(void)
 
     backend->startup_func = sentry__breakpad_backend_startup;
     backend->shutdown_func = sentry__breakpad_backend_shutdown;
+    backend->except_func = sentry__breakpad_backend_except;
     backend->free_func = NULL;
     backend->flush_scope_func = NULL;
     backend->add_breadcrumb_func = NULL;
diff --git a/src/backends/sentry_backend_crashpad.cpp b/src/backends/sentry_backend_crashpad.cpp
index 0a32cdd83..b672b085e 100644
--- a/src/backends/sentry_backend_crashpad.cpp
+++ b/src/backends/sentry_backend_crashpad.cpp
@@ -243,6 +243,14 @@ sentry__crashpad_backend_free(sentry_backend_t *backend)
     sentry_free(data);
 }
 
+static void sentry__crashpad_backend_except(
+    sentry_backend_t *UNUSED(backend), sentry_ucontext_t *context)
+{
+#ifdef SENTRY_PLATFORM_WINDOWS
+    crashpad::CrashpadClient::DumpAndCrash(&context->exception_ptrs);
+#endif
+}
+
 sentry_backend_t *
 sentry__backend_new(void)
 {
@@ -259,6 +267,7 @@ sentry__backend_new(void)
 
     backend->startup_func = sentry__crashpad_backend_startup;
     backend->shutdown_func = sentry__crashpad_backend_shutdown;
+    backend->except_func = sentry__crashpad_backend_except;
     backend->free_func = sentry__crashpad_backend_free;
     backend->flush_scope_func = sentry__crashpad_backend_flush_scope;
     backend->add_breadcrumb_func = sentry__crashpad_backend_add_breadcrumb;
diff --git a/src/backends/sentry_backend_inproc.c b/src/backends/sentry_backend_inproc.c
index 3d74b7bc5..05976aab1 100644
--- a/src/backends/sentry_backend_inproc.c
+++ b/src/backends/sentry_backend_inproc.c
@@ -150,12 +150,18 @@ static void
 handle_signal(int signum, siginfo_t *info, void *user_context)
 {
     sentry_ucontext_t uctx;
+    uctx.signum = signum;
     uctx.siginfo = info;
     uctx.user_context = (ucontext_t *)user_context;
+    handle_ucontext(&uctx);
+}
 
+static void
+handle_ucontext(sentry_ucontext_t* uctx)
+{
     const struct signal_slot *sig_slot = NULL;
     for (int i = 0; i < SIGNAL_COUNT; ++i) {
-        if (SIGNAL_DEFINITIONS[i].signum == signum) {
+        if (SIGNAL_DEFINITIONS[i].signum == uctx->signum) {
             sig_slot = &SIGNAL_DEFINITIONS[i];
         }
     }
@@ -178,7 +184,7 @@ handle_signal(int signum, siginfo_t *info, void *user_context)
     // only dumps to disk at the moment.
     SENTRY_DEBUG("capturing event from signal");
     sentry__end_current_session_with_status(SENTRY_SESSION_STATUS_CRASHED);
-    sentry_capture_event(make_signal_event(sig_slot, &uctx));
+    sentry_capture_event(make_signal_event(sig_slot, uctx));
 
     // after capturing the crash event, try to dump all the in-flight data of
     // the previous transport
@@ -221,6 +227,7 @@ sentry__backend_new(void)
 
     backend->startup_func = startup_inproc_backend;
     backend->shutdown_func = NULL;
+    backend->except_func = handle_ucontext;
     backend->free_func = free_backend;
     backend->flush_scope_func = NULL;
     backend->add_breadcrumb_func = NULL;
diff --git a/src/sentry_backend.h b/src/sentry_backend.h
index bd25872cb..95ba05895 100644
--- a/src/sentry_backend.h
+++ b/src/sentry_backend.h
@@ -6,10 +6,12 @@
 #include "sentry_scope.h"
 
 struct sentry_backend_s;
+struct sentry_ucontext_s;
 typedef struct sentry_backend_s {
     void (*startup_func)(struct sentry_backend_s *);
     void (*shutdown_func)(struct sentry_backend_s *);
     void (*free_func)(struct sentry_backend_s *);
+    void (*except_func)(struct sentry_backend_s *, struct sentry_ucontext_s *);
     void (*flush_scope_func)(
         struct sentry_backend_s *, const sentry_scope_t *scope);
     void (*add_breadcrumb_func)(
diff --git a/src/sentry_core.c b/src/sentry_core.c
index 9c9ef0e1c..71cda9607 100644
--- a/src/sentry_core.c
+++ b/src/sentry_core.c
@@ -253,6 +253,14 @@ sentry_capture_event(sentry_value_t event)
     return event_id;
 }
 
+void sentry_handle_exception(sentry_ucontext_t *context)
+{
+    SENTRY_DEBUG("handling exception");
+    if (g_options->backend && g_options->backend->except_func) {
+        g_options->backend->except_func(g_options->backend, context);
+    }
+}
+
 sentry_options_t *
 sentry_options_new(void)
 {

From 931cc6087a27321f0d70117b634732180561e691 Mon Sep 17 00:00:00 2001
From: cammm <81903+cammm@users.noreply.github.com>
Date: Fri, 27 Mar 2020 08:38:32 -0700
Subject: [PATCH 2/5] Mark handle except as experimental

---
 include/sentry.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/sentry.h b/include/sentry.h
index f7799ce9d..ef1eef4dd 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -654,7 +654,7 @@ SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
 /*
  * Captures an exception to be handled by the backend.
  */
-SENTRY_API void sentry_handle_exception(sentry_ucontext_t *context);
+SENTRY_EXPERIMENTAL_API void sentry_handle_exception(sentry_ucontext_t *context);
 
 /*
  * Adds the breadcrumb to be sent in case of an event.

From 8c2899a02d136702acb9301260f63ca7a77f22d6 Mon Sep 17 00:00:00 2001
From: cammm <81903+cammm@users.noreply.github.com>
Date: Fri, 27 Mar 2020 09:03:17 -0700
Subject: [PATCH 3/5] Fixing compile errors on linux / mac

---
 src/backends/sentry_backend_breakpad.cpp |  2 +-
 src/backends/sentry_backend_inproc.c     | 30 ++++++++++++++----------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/src/backends/sentry_backend_breakpad.cpp b/src/backends/sentry_backend_breakpad.cpp
index e536a8150..0684246a1 100644
--- a/src/backends/sentry_backend_breakpad.cpp
+++ b/src/backends/sentry_backend_breakpad.cpp
@@ -147,7 +147,7 @@ sentry__breakpad_backend_shutdown(sentry_backend_t *backend)
 }
 
 static void sentry__breakpad_backend_except(
-    sentry_backend_t *UNUSED(backend), sentry_ucontext_t *context)
+    sentry_backend_t *backend, sentry_ucontext_t *context)
 {
     google_breakpad::ExceptionHandler *eh
         = (google_breakpad::ExceptionHandler *)backend->data;
diff --git a/src/backends/sentry_backend_inproc.c b/src/backends/sentry_backend_inproc.c
index 05976aab1..5e8cb794c 100644
--- a/src/backends/sentry_backend_inproc.c
+++ b/src/backends/sentry_backend_inproc.c
@@ -146,16 +146,6 @@ make_signal_event(
     return event;
 }
 
-static void
-handle_signal(int signum, siginfo_t *info, void *user_context)
-{
-    sentry_ucontext_t uctx;
-    uctx.signum = signum;
-    uctx.siginfo = info;
-    uctx.user_context = (ucontext_t *)user_context;
-    handle_ucontext(&uctx);
-}
-
 static void
 handle_ucontext(sentry_ucontext_t* uctx)
 {
@@ -198,7 +188,23 @@ handle_ucontext(sentry_ucontext_t* uctx)
     // forward as we're not restoring the page allocator.
     reset_signal_handlers();
     sentry__leave_signal_handler();
-    invoke_signal_handler(signum, info, user_context);
+    invoke_signal_handler(uctx->signum, uctx->info, (void *)uctx->user_context);
+}
+
+static void
+handle_signal(int signum, siginfo_t *info, void *user_context)
+{
+    sentry_ucontext_t uctx;
+    uctx.signum = signum;
+    uctx.siginfo = info;
+    uctx.user_context = (ucontext_t *)user_context;
+    handle_ucontext(&uctx);
+}
+
+static void handle_except(
+    sentry_backend_t *UNUSED(backend), sentry_ucontext_t *uctx)
+{
+    handle_ucontext(uctx);
 }
 
 static void
@@ -227,7 +233,7 @@ sentry__backend_new(void)
 
     backend->startup_func = startup_inproc_backend;
     backend->shutdown_func = NULL;
-    backend->except_func = handle_ucontext;
+    backend->except_func = handle_except;
     backend->free_func = free_backend;
     backend->flush_scope_func = NULL;
     backend->add_breadcrumb_func = NULL;

From 17362852b5f84c4f57f23d4c0e59b46b050ae2cf Mon Sep 17 00:00:00 2001
From: cammm <81903+cammm@users.noreply.github.com>
Date: Fri, 27 Mar 2020 09:20:25 -0700
Subject: [PATCH 4/5] More mac/linux compile errors

---
 src/backends/sentry_backend_crashpad.cpp | 4 ++++
 src/backends/sentry_backend_inproc.c     | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/backends/sentry_backend_crashpad.cpp b/src/backends/sentry_backend_crashpad.cpp
index b672b085e..1a247bae8 100644
--- a/src/backends/sentry_backend_crashpad.cpp
+++ b/src/backends/sentry_backend_crashpad.cpp
@@ -248,6 +248,10 @@ static void sentry__crashpad_backend_except(
 {
 #ifdef SENTRY_PLATFORM_WINDOWS
     crashpad::CrashpadClient::DumpAndCrash(&context->exception_ptrs);
+#else
+    // TODO: Crashpad has the ability to do this on linux / mac but the
+    // method interface is not exposed for it, a patch would be required
+    (void)context;
 #endif
 }
 
diff --git a/src/backends/sentry_backend_inproc.c b/src/backends/sentry_backend_inproc.c
index 5e8cb794c..028bdf4e8 100644
--- a/src/backends/sentry_backend_inproc.c
+++ b/src/backends/sentry_backend_inproc.c
@@ -188,7 +188,7 @@ handle_ucontext(sentry_ucontext_t* uctx)
     // forward as we're not restoring the page allocator.
     reset_signal_handlers();
     sentry__leave_signal_handler();
-    invoke_signal_handler(uctx->signum, uctx->info, (void *)uctx->user_context);
+    invoke_signal_handler(uctx->signum, uctx->siginfo, (void *)uctx->user_context);
 }
 
 static void

From 7cf948bff6677a1e56ad3822baab5e217dc076a0 Mon Sep 17 00:00:00 2001
From: cammm <81903+cammm@users.noreply.github.com>
Date: Fri, 27 Mar 2020 09:40:56 -0700
Subject: [PATCH 5/5] Review feedback

---
 include/sentry.h     | 4 +++-
 src/sentry_backend.h | 1 -
 src/sentry_core.c    | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/sentry.h b/include/sentry.h
index ef1eef4dd..7cbec99f0 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -653,8 +653,10 @@ SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
 
 /*
  * Captures an exception to be handled by the backend.
+ *
+ * This is safe to be called from a crashing thread and may not return.
  */
-SENTRY_EXPERIMENTAL_API void sentry_handle_exception(sentry_ucontext_t *context);
+SENTRY_EXPERIMENTAL_API void sentry_handle_exception(sentry_ucontext_t *uctx);
 
 /*
  * Adds the breadcrumb to be sent in case of an event.
diff --git a/src/sentry_backend.h b/src/sentry_backend.h
index 95ba05895..cd7ea1f14 100644
--- a/src/sentry_backend.h
+++ b/src/sentry_backend.h
@@ -6,7 +6,6 @@
 #include "sentry_scope.h"
 
 struct sentry_backend_s;
-struct sentry_ucontext_s;
 typedef struct sentry_backend_s {
     void (*startup_func)(struct sentry_backend_s *);
     void (*shutdown_func)(struct sentry_backend_s *);
diff --git a/src/sentry_core.c b/src/sentry_core.c
index 71cda9607..70c2d9972 100644
--- a/src/sentry_core.c
+++ b/src/sentry_core.c
@@ -253,11 +253,11 @@ sentry_capture_event(sentry_value_t event)
     return event_id;
 }
 
-void sentry_handle_exception(sentry_ucontext_t *context)
+void sentry_handle_exception(sentry_ucontext_t *uctx)
 {
     SENTRY_DEBUG("handling exception");
     if (g_options->backend && g_options->backend->except_func) {
-        g_options->backend->except_func(g_options->backend, context);
+        g_options->backend->except_func(g_options->backend, uctx);
     }
 }