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//===- xray_interface.h -----------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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 <cstddef>
#include <cstdint>
extern "C" {
/// Synchronize this with AsmPrinter::SledKind in LLVM.
enum XRayEntryType {
ENTRY = 0,
EXIT = 1,
TAIL = 2,
LOG_ARGS_ENTRY = 3,
CUSTOM_EVENT = 4,
TYPED_EVENT = 5,
};
/// 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();
/// Use XRay to log the first argument of each (instrumented) function call.
/// When this function exits, all threads will have observed the effect and
/// start logging their subsequent affected function calls (if patched).
///
/// Returns 1 on success, 0 on error.
extern int __xray_set_handler_arg1(void (*entry)(int32_t, XRayEntryType,
uint64_t));
/// Disables the XRay handler used to log first arguments of function calls.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_handler_arg1();
/// Provide a function to invoke when XRay encounters a custom event.
extern int __xray_set_customevent_handler(void (*entry)(void *, std::size_t));
/// This removes whatever the currently provided custom event handler is.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_customevent_handler();
/// Set a handler for xray typed event logging. The first parameter is a type
/// identifier, the second is a payload, and the third is the payload size.
/// NOTE: fdrLoggingHandleTypedEvent only supports uint16_t event type.
extern int __xray_set_typedevent_handler(void (*entry)(size_t, const void *,
size_t));
/// Removes the currently set typed event handler.
/// Returns 1 on success, 0 on error.
extern int __xray_remove_typedevent_handler();
extern uint16_t __xray_register_event_type(const char *event_type);
enum XRayPatchingStatus {
NOT_INITIALIZED = 0,
SUCCESS = 1,
ONGOING = 2,
FAILED = 3,
};
/// This tells XRay to patch the instrumentation points in all currently loaded
/// objects. See XRayPatchingStatus for possible result values.
extern XRayPatchingStatus __xray_patch();
/// This tells XRay to patch the instrumentation points in the given object.
/// See XRayPatchingStatus for possible result values.
extern XRayPatchingStatus __xray_patch_object(int32_t ObjId);
/// Reverses the effect of __xray_patch(). See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_unpatch();
/// Reverses the effect of __xray_patch_object. See XRayPatchingStatus for
/// possible result values.
extern XRayPatchingStatus __xray_unpatch_object(int32_t ObjId);
/// This unpacks the given (packed) function id and patches
/// the corresponding function. See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_patch_function(int32_t FuncId);
/// This patches a specific function in the given object. See XRayPatchingStatus
/// for possible result values.
extern XRayPatchingStatus __xray_patch_function_in_object(int32_t FuncId,
int32_t ObjId);
/// This unpacks the given (packed) function id and unpatches
/// the corresponding function. See XRayPatchingStatus for possible
/// result values.
extern XRayPatchingStatus __xray_unpatch_function(int32_t FuncId);
/// This unpatches a specific function in the given object.
/// See XRayPatchingStatus for possible result values.
extern XRayPatchingStatus __xray_unpatch_function_in_object(int32_t FuncId,
int32_t ObjId);
/// This function unpacks the given (packed) function id and returns the address
/// of the corresponding function. We return 0 if we encounter any error, even
/// if 0 may be a valid function address.
extern uintptr_t __xray_function_address(int32_t FuncId);
/// This function returns the address of the function in the given object
/// provided valid function and object ids. We return 0 if we encounter any
/// error, even if 0 may be a valid function address.
extern uintptr_t __xray_function_address_in_object(int32_t FuncId,
int32_t ObjId);
/// This function returns the maximum valid function id for the main executable
/// (object id = 0). Returns 0 if we encounter errors (when there are no
/// instrumented functions, etc.).
extern size_t __xray_max_function_id();
/// This function returns the maximum valid function id for the given object.
/// Returns 0 if we encounter errors (when there are no instrumented functions,
/// etc.).
extern size_t __xray_max_function_id_in_object(int32_t ObjId);
/// This function returns the number of previously registered objects
/// (executable + loaded DSOs). Returns 0 if XRay has not been initialized.
extern size_t __xray_num_objects();
/// Unpacks the function id from the given packed id.
extern int32_t __xray_unpack_function_id(int32_t PackedId);
/// Unpacks the object id from the given packed id.
extern int32_t __xray_unpack_object_id(int32_t PackedId);
/// Creates and returns a packed id from the given function and object ids.
/// If the ids do not fit within the reserved number of bits for each part, the
/// high bits are truncated.
extern int32_t __xray_pack_id(int32_t FuncId, int32_t ObjId);
/// Initialize the required XRay data structures. This is useful in cases where
/// users want to control precisely when the XRay instrumentation data
/// structures are initialized, for example when the XRay library is built with
/// the XRAY_NO_PREINIT preprocessor definition.
///
/// Calling __xray_init() more than once is safe across multiple threads.
extern void __xray_init();
} // end extern "C"
#endif // XRAY_XRAY_INTERFACE_H
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