[WIP] fix!: apply scope before on_crash callback

CHANGELOG.md

@@ -6,6 +6,9 @@
 
 - Attachment APIs now use `sentry_value_t` and `sentry_uuid_t` instead of `sentry_attachment_t *` handles. Most attachment APIs, function names and arguments, are otherwise unchanged. ([#1974](https://github.com/getsentry/sentry-native/pull/1974))
 - `sentry_init()` now consumes `<db>/last_crash` after caching its value, aligning crashed-last-run behavior with other Sentry SDKs. ([#2023](https://github.com/getsentry/sentry-native/pull/2023))
+- Change the `hint` parameter of `before_send` callbacks (`sentry_event_function_t`) from `void *` to `sentry_hint_t *`. Update callbacks registered with `sentry_options_set_before_send` to use the new parameter type. ([#2099](https://github.com/getsentry/sentry-native/pull/2099))
+- Add a `sentry_hint_t *hint` argument to `on_crash` callbacks. ([#2112](https://github.com/getsentry/sentry-native/pull/2112))
+- Add a `sentry_hint_t *hint` argument to `sentry_scope_capture_event`. Pass `NULL` if no hint is needed. ([#2099](https://github.com/getsentry/sentry-native/pull/2099))
 - Remove `sentry_options_get/set_enable_logs` and `sentry_options_get/set_enable_metrics`. ([#1980](https://github.com/getsentry/sentry-native/pull/1980))
   > Structured logs and metrics have been enabled by default since `0.13`, and the options were deprecated and made no-ops in `0.16`.
   >
@@ -16,10 +19,13 @@
 - Add `sentry_attachment_from_file/bytes` (and their wide-string variants) for creating attachment values that can be fully configured before they are added. ([#2079](https://github.com/getsentry/sentry-native/pull/2079))
 - Add `sentry_add_attachment`, `sentry_scope_add_attachment`, and `sentry_hint_add_attachment` for adding configured attachments to the global scope, a specific scope, or a hint. These functions consume and freeze the attachment value. ([#2079](https://github.com/getsentry/sentry-native/pull/2079), [#1974](https://github.com/getsentry/sentry-native/pull/1974))
 - Add `sentry_start_new_trace()` as a clearer name for starting a new trace. ([#2095](https://github.com/getsentry/sentry-native/pull/2095))
+- Add hint support to `sentry_scope_capture_event` to pass event-specific attachments. The hint is also passed to `before_send` and `on_crash`, which can modify attachments before the event is sent. ([#2099](https://github.com/getsentry/sentry-native/pull/2099), [#2112](https://github.com/getsentry/sentry-native/pull/2112))
+- Add `sentry_hint_remove_attachment` and `sentry_hint_clear_attachments`. ([#2099](https://github.com/getsentry/sentry-native/pull/2099))
 
 **Fixes**:
 
 - Reduce lock contention for multi-threaded log and metric capture by allowing concurrent reads of scope data, and reusing a single options reference throughout each capture. ([#2091](https://github.com/getsentry/sentry-native/pull/2091), [#2094](https://github.com/getsentry/sentry-native/pull/2094))
+- Apply scope data before invoking `on_crash` while preserving scope changes made by the callback. ([#2119](https://github.com/getsentry/sentry-native/pull/2119))
 
 **Other changes**:
 

examples/example.c

@@ -127,11 +127,15 @@ traces_sampler_callback(const sentry_transaction_context_t *transaction_ctx,
 }
 
 static sentry_value_t
-before_send_callback(sentry_value_t event, void *hint, void *user_data)
+before_send_callback(sentry_value_t event, sentry_hint_t *hint, void *user_data)
 {
-    (void)hint;
     (void)user_data;
 
+    sentry_hint_clear_attachments(hint);
+    sentry_hint_add_attachment(hint,
+        sentry_attachment_from_bytes(
+            "before_send", strlen("before_send"), "callback.txt"));
+
     // make our mark on the event
     sentry_value_set_by_key(
         event, "adapted_by", sentry_value_new_string("before_send"));
@@ -142,7 +146,7 @@ before_send_callback(sentry_value_t event, void *hint, void *user_data)
 
 static sentry_value_t
 discarding_before_send_callback(
-    sentry_value_t event, void *hint, void *user_data)
+    sentry_value_t event, sentry_hint_t *hint, void *user_data)
 {
     (void)hint;
     (void)user_data;
@@ -153,10 +157,11 @@ discarding_before_send_callback(
 }
 
 static sentry_value_t
-discarding_on_crash_callback(
-    const sentry_ucontext_t *uctx, sentry_value_t event, void *user_data)
+discarding_on_crash_callback(const sentry_ucontext_t *uctx,
+    sentry_value_t event, sentry_hint_t *hint, void *user_data)
 {
     (void)uctx;
+    (void)hint;
     (void)user_data;
 
     // discard event and signal backend to stop further processing
@@ -165,12 +170,22 @@ discarding_on_crash_callback(
 }
 
 static sentry_value_t
-on_crash_callback(
-    const sentry_ucontext_t *uctx, sentry_value_t event, void *user_data)
+on_crash_callback(const sentry_ucontext_t *uctx, sentry_value_t event,
+    sentry_hint_t *hint, void *user_data)
 {
     (void)uctx;
     (void)user_data;
 
+    sentry_hint_clear_attachments(hint);
+    sentry_hint_add_attachment(hint,
+        sentry_attachment_from_bytes(
+            "on_crash", strlen("on_crash"), "callback.txt"));
+
+    sentry_value_t tags = sentry_value_get_by_key(event, "tags");
+    sentry_value_set_by_key(event, "on_crash_scope_tag",
+        sentry_value_incref(sentry_value_get_by_key(tags, "expected-tag")));
+    sentry_set_tag("test.on-crash", "added-by-on-crash");
+
     // tell the backend to retain the event
     return event;
 }
@@ -230,10 +245,11 @@ on_crashed_last_run_callback(const sentry_envelope_t *envelope, void *user_data)
 }
 
 static sentry_value_t
-restart_on_crash(
-    const sentry_ucontext_t *uctx, sentry_value_t event, void *user_data)
+restart_on_crash(const sentry_ucontext_t *uctx, sentry_value_t event,
+    sentry_hint_t *hint, void *user_data)
 {
     (void)uctx;
+    (void)hint;
 
 #ifdef SENTRY_PLATFORM_WINDOWS
     wchar_t **argv = user_data;
@@ -1247,7 +1263,7 @@ main(int argc, char **argv)
             sentry_scope_add_attachment(scope, bytes);
         }
 
-        sentry_scope_capture_event(scope, event);
+        sentry_scope_capture_event(scope, event, NULL);
     }
 
     if (has_arg(argc, argv, "capture-multiple")) {

include/sentry.h

@@ -1478,6 +1478,13 @@ SENTRY_API void sentry_options_set_send_default_pii(
     sentry_options_t *opts, int value);
 #endif
 
+/**
+ * A hint that can be passed to capture functions to provide additional context,
+ * such as attachments.
+ */
+struct sentry_hint_s;
+typedef struct sentry_hint_s sentry_hint_t;
+
 /**
  * Type of the `before_send` callback.
  *
@@ -1486,6 +1493,9 @@ SENTRY_API void sentry_options_set_send_default_pii(
  * call `sentry_value_decref` on the provided event and return a
  * `sentry_value_new_null()` instead.
  *
+ * The hint is always provided and can be used to modify attachments on the
+ * event.
+ *
  * If you have set an `on_crash` callback (independent of whether it discards or
  * retains the event), `before_send` will no longer be invoked for crash-events,
  * which allows you to better distinguish between crashes and all other events
@@ -1510,7 +1520,7 @@ SENTRY_API void sentry_options_set_send_default_pii(
  * though a crash report will be sent.
  */
 typedef sentry_value_t (*sentry_event_function_t)(
-    sentry_value_t event, void *hint, void *user_data);
+    sentry_value_t event, sentry_hint_t *hint, void *user_data);
 
 /**
  * Sets the `before_send` callback.
@@ -1530,9 +1540,15 @@ SENTRY_API void sentry_options_set_before_send(
  * `sentry_value_decref` on the provided event and return a
  * `sentry_value_new_null()` instead.
  *
+ * The hint is always provided and can be used to modify attachments on the
+ * event.
+ *
+ * The current scope is applied before invoking the callback. Scope changes made
+ * from inside the callback are also applied to the returned event.
+ *
  * Only the `inproc` backend currently fills the passed-in event with crash
  * meta-data. Since both `breakpad` and `crashpad` use minidumps to capture the
- * crash state, the passed-in event is empty when using these backends. Changes
+ * crash state, their events contain scope data but no crash meta-data. Changes
  * to the event from inside the hooks will be passed along, but in the case of
  * the minidump backends these changes might get overwritten during server-side
  * ingestion and processing. This primarily affects the exception payloads which
@@ -1570,8 +1586,8 @@ SENTRY_API void sentry_options_set_before_send(
  *    exception-handler, it will not be invoked when such a crash happened, even
  *    though a crash report will be sent.
  */
-typedef sentry_value_t (*sentry_crash_function_t)(
-    const sentry_ucontext_t *uctx, sentry_value_t event, void *user_data);
+typedef sentry_value_t (*sentry_crash_function_t)(const sentry_ucontext_t *uctx,
+    sentry_value_t event, sentry_hint_t *hint, void *user_data);
 
 /**
  * Sets the `on_crash` callback.
@@ -2592,15 +2608,18 @@ SENTRY_API sentry_uuid_t sentry_scope_get_last_event_id(
 SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
 
 /**
- * Sends a sentry event with a scope.
+ * Sends a sentry event with a scope and a hint.
+ *
+ * This function takes ownership of the event and hint, which will be freed
+ * automatically. The hint may be NULL.
  *
  * If `scope` is a local scope (`sentry_local_scope_new`), this takes ownership
  * of it and frees it. If `scope` is user-owned (`sentry_scope_new` or
  * `sentry_scope_clone`), it is applied but not freed, so it can be reused; free
  * it yourself with `sentry_scope_free`.
  */
 SENTRY_API sentry_uuid_t sentry_scope_capture_event(
-    sentry_scope_t *scope, sentry_value_t event);
+    sentry_scope_t *scope, sentry_value_t event, sentry_hint_t *hint);
 
 /**
  * Deprecated alias for `sentry_scope_capture_event`. Note the reversed argument
@@ -4139,16 +4158,7 @@ SENTRY_API sentry_value_t sentry_value_new_feedback_n(const char *message,
 SENTRY_API void sentry_capture_feedback(sentry_value_t user_feedback);
 
 /**
- * A hint that can be passed to capture functions to provide additional context,
- * such as attachments.
- */
-struct sentry_hint_s;
-typedef struct sentry_hint_s sentry_hint_t;
-
-/**
- * Creates a new hint to be passed into
- * - `sentry_capture_feedback_with_hint`
- * - `sentry_scope_capture_feedback`
+ * Creates a new hint to be passed into capture functions.
  */
 SENTRY_API sentry_hint_t *sentry_hint_new(void);
 
@@ -4202,6 +4212,17 @@ SENTRY_API sentry_uuid_t sentry_hint_attach_bytesw_n(sentry_hint_t *hint,
     size_t filename_len);
 #endif
 
+/**
+ * Removes an attachment from the hint by its ID. Does not modify scopes.
+ */
+SENTRY_API void sentry_hint_remove_attachment(
+    sentry_hint_t *hint, sentry_uuid_t attachment_id);
+
+/**
+ * Removes all attachments from the hint. Does not modify scopes.
+ */
+SENTRY_API void sentry_hint_clear_attachments(sentry_hint_t *hint);
+
 /**
  * Captures a manually created feedback with a hint and sends it to Sentry.
  *
@@ -4237,7 +4258,8 @@ SENTRY_API sentry_uuid_t sentry_scope_capture_feedback(
  * callback needs to call `sentry_value_decref` on the provided event and
  * return a `sentry_value_new_null()` instead.
  *
- * The hint is always provided and can be used to add attachments to the event.
+ * The hint is always provided and can be used to modify attachments on the
+ * event.
  *
  * Feedback events do not go through the `before_send` callback.
  */