Add plumbing for getting crashpad_handler's IPC pipe name (#10)

This will allow a child process to connect to the pipe server rather than starting its own crashpad_handler.

include/sentry.h

@@ -1212,6 +1212,14 @@ SENTRY_API void sentry_options_set_database_pathw(
     sentry_options_t *opts, const wchar_t *path);
 SENTRY_API void sentry_options_set_database_pathw_n(
     sentry_options_t *opts, const wchar_t *path, size_t path_len);
+
+/**
+ * Returns the name of the named pipe where the Crashpad handler is listening
+ * for child connections if Crashpad is active backend.
+ */
+SENTRY_API const wchar_t *sentry_options_get_handler_ipc_pipew(
+    sentry_options_t *opts);
+
 #endif
 
 /**

src/backends/sentry_backend_crashpad.cpp

@@ -355,6 +355,11 @@ crashpad_backend_startup(
             annotations, arguments,
             /* restartable */ true,
             /* asynchronous_start */ false, attachments);
+#ifdef SENTRY_PLATFORM_WINDOWS
+        std::wstring pipe_name = data->client->GetHandlerIPCPipe();
+        const_cast<sentry_options_t *>(options)->handler_ipc_pipe
+            = sentry__path_new(pipe_name.c_str());
+#endif
         sentry_free(minidump_url);
     } else {
         SENTRY_WARN(

src/sentry_options.c

@@ -537,6 +537,12 @@ sentry_options_set_database_pathw(sentry_options_t *opts, const wchar_t *path)
 }
 #endif
 
+const wchar_t *
+sentry_options_get_handler_ipc_pipew(sentry_options_t *opts)
+{
+    return opts->handler_ipc_pipe ? opts->handler_ipc_pipe->path : NULL;
+}
+
 /**
  * Sets the maximum number of spans that can be attached to a
  * transaction.

src/sentry_options.h

@@ -68,6 +68,11 @@ typedef struct sentry_options_s {
     struct sentry_backend_s *backend;
     sentry_session_t *session;
 
+#ifdef SENTRY_PLATFORM_WINDOWS
+    /* Filled out after crashpad startup, only on Windows */
+    sentry_path_t* handler_ipc_pipe;
+#endif
+
     long user_consent;
     long refcount;
     uint64_t shutdown_timeout;