llvm-project/compiler-rt/include/xray/xray_interface.h

66 lines
2.4 KiB
C++

//===-- xray_interface.h ----------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of XRay, a dynamic runtime instrumentation system.
//
// APIs for controlling XRay functionality explicitly.
//===----------------------------------------------------------------------===//
#ifndef XRAY_XRAY_INTERFACE_H
#define XRAY_XRAY_INTERFACE_H
#include <cstdint>
extern "C" {
enum XRayEntryType { ENTRY = 0, EXIT = 1, TAIL = 2 };
// Provide a function to invoke for when instrumentation points are hit. This is
// a user-visible control surface that overrides the default implementation. The
// function provided should take the following arguments:
//
// - function id: an identifier that indicates the id of a function; this id
// is generated by xray; the mapping between the function id
// and the actual function pointer is available through
// __xray_table.
// - entry type: identifies what kind of instrumentation point was encountered
// (function entry, function exit, etc.). See the enum
// XRayEntryType for more details.
//
// The user handler must handle correctly spurious calls after this handler is
// removed or replaced with another handler, because it would be too costly for
// XRay runtime to avoid spurious calls.
// To prevent circular calling, the handler function itself and all its
// direct&indirect callees must not be instrumented with XRay, which can be
// achieved by marking them all with: __attribute__((xray_never_instrument))
//
// Returns 1 on success, 0 on error.
extern int __xray_set_handler(void (*entry)(int32_t, XRayEntryType));
// This removes whatever the currently provided handler is. Returns 1 on
// success, 0 on error.
extern int __xray_remove_handler();
enum XRayPatchingStatus {
NOT_INITIALIZED = 0,
SUCCESS = 1,
ONGOING = 2,
FAILED = 3,
};
// This tells XRay to patch the instrumentation points. See XRayPatchingStatus
// for possible result values.
extern XRayPatchingStatus __xray_patch();
// Reverses the effect of __xray_patch(). See XRayPatchingStatus for possible
// result values.
extern XRayPatchingStatus __xray_unpatch();
}
#endif