X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fpayload-view.h;h=af8519ab32641aaab739fa66985179ee025b47ba;hp=47c2c8c917d29e33e6956818ff0b2f31de9db1aa;hb=7966af5763c4aaca39df9bbfa9277ff15715c720;hpb=18eec1c924daf8d63a5f2cc06b1c1fdd9a838c6e

diff --git a/src/common/payload-view.h b/src/common/payload-view.h
index 47c2c8c91..af8519ab3 100644
--- a/src/common/payload-view.h
+++ b/src/common/payload-view.h
@@ -11,6 +11,10 @@
 #include <common/buffer-view.h>
 #include <common/dynamic-array.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct lttng_payload;
 struct fd_handle;
 
@@ -46,13 +50,43 @@ struct fd_handle;
 struct lttng_payload_view {
 	struct lttng_buffer_view buffer;
 	/* private */
-	const struct lttng_dynamic_pointer_array _fd_handles;
+
+	/*
+	 * Avoid a -Wreturn-type-c-linkage warning with clang.
+	 * gcc is more permissive with regards to this warning, but
+	 * clang is right that a structure containing a _const_ structure is not
+	 * a trivial type in the eyes of the C++ standard, theoritically affecting its
+	 * compatibility with C from an ABI standpoint:
+	 *   A trivial class is a class that is trivially copyable and has one or
+	 *   more default constructors, all of which are either trivial or deleted and
+	 *   at least one of which is not deleted.
+	 *
+	 * A const member implicitly deletes lttng_payload_view's constructor,
+	 * making it non-trivial. This is not a problem for the moment as we are
+	 * transitioning all code to C++11.
+	 */
+#if !defined(__cplusplus)
+	const
+#endif
+	struct lttng_dynamic_pointer_array _fd_handles;
+
 	struct {
 		size_t *p_fd_handles_position;
 		size_t fd_handles_position;
 	} _iterator;
 };
 
+/**
+ * Checks if a payload view's buffer is safe to access.
+ *
+ * After calling the payload view creation functions, callers should verify
+ * if the resquested length (if any is explicitly provided) could be mapped
+ * to a new view.
+ *
+ * @view	Payload to validate
+ */
+bool lttng_payload_view_is_valid(const struct lttng_payload_view *view);
+
 /**
  * Return a payload view referencing a subset of a payload.
  *
@@ -62,7 +96,6 @@ struct lttng_payload_view {
  *		cause the view to reference the whole payload from the
  *		offset provided.
  */
-LTTNG_HIDDEN
 struct lttng_payload_view lttng_payload_view_from_payload(
 		const struct lttng_payload *payload, size_t offset,
 		ptrdiff_t len);
@@ -77,7 +110,6 @@ struct lttng_payload_view lttng_payload_view_from_payload(
  *		cause the payload view to reference the whole payload view's
  *		buffer view from the offset provided.
  */
-LTTNG_HIDDEN
 struct lttng_payload_view lttng_payload_view_from_view(
 		struct lttng_payload_view *view, size_t offset,
 		ptrdiff_t len);
@@ -94,7 +126,6 @@ struct lttng_payload_view lttng_payload_view_from_view(
  *		cause the payload view to reference the whole payload from the
  *		offset provided.
  */
-LTTNG_HIDDEN
 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
 		const struct lttng_dynamic_buffer *buffer, size_t offset,
 		ptrdiff_t len);
@@ -111,7 +142,6 @@ struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  *		cause the payload view to reference the whole payload from the
  *		offset provided.
  */
-LTTNG_HIDDEN
 struct lttng_payload_view lttng_payload_view_from_buffer_view(
 		const struct lttng_buffer_view *view, size_t offset,
 		ptrdiff_t len);
@@ -127,7 +157,6 @@ struct lttng_payload_view lttng_payload_view_from_buffer_view(
  * Note that a payload view never assumes the ownership of the memory it
  * references.
  */
-LTTNG_HIDDEN
 struct lttng_payload_view lttng_payload_view_init_from_buffer(
 		const char *src, size_t offset, ptrdiff_t len);
 
@@ -138,7 +167,6 @@ struct lttng_payload_view lttng_payload_view_init_from_buffer(
  *
  * Returns the number of file descriptor handles left on success, -1 on error.
  */
-LTTNG_HIDDEN
 int lttng_payload_view_get_fd_handle_count(
 		const struct lttng_payload_view *payload_view);
 
@@ -151,8 +179,11 @@ int lttng_payload_view_get_fd_handle_count(
  *
  * Returns an fd_handle on success, -1 on error.
  */
-LTTNG_HIDDEN
 struct fd_handle *lttng_payload_view_pop_fd_handle(
 		struct lttng_payload_view *payload_view);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* LTTNG_PAYLOAD_VIEW_H */