lib/profile/InstrProfiling.h

/*===- InstrProfiling.h- Support library for PGO instrumentation ----------===*\
|*
|* 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
|*
\*===----------------------------------------------------------------------===*/

#ifndef PROFILE_INSTRPROFILING_H_
#define PROFILE_INSTRPROFILING_H_

#include "InstrProfilingPort.h"

#define INSTR_PROF_VISIBILITY COMPILER_RT_VISIBILITY
#include "InstrProfData.inc"

enum ValueKind {
#define VALUE_PROF_KIND(Enumerator, Value) Enumerator = Value,
#include "InstrProfData.inc"
};

typedef void *IntPtrT;
typedef struct COMPILER_RT_ALIGNAS(INSTR_PROF_DATA_ALIGNMENT)
    __llvm_profile_data {
#define INSTR_PROF_DATA(Type, LLVMType, Name, Initializer) Type Name;
#include "InstrProfData.inc"
} __llvm_profile_data;

typedef struct __llvm_profile_header {
#define INSTR_PROF_RAW_HEADER(Type, Name, Initializer) Type Name;
#include "InstrProfData.inc"
} __llvm_profile_header;

typedef struct ValueProfNode * PtrToNodeT;
typedef struct ValueProfNode {
#define INSTR_PROF_VALUE_NODE(Type, LLVMType, Name, Initializer) Type Name;
#include "InstrProfData.inc"
} ValueProfNode;

/*!
 * \brief Get number of bytes necessary to pad the argument to eight
 * byte boundary.
 */
uint8_t __llvm_profile_get_num_padding_bytes(uint64_t SizeInBytes);

/*!
 * \brief Get required size for profile buffer.
 */
uint64_t __llvm_profile_get_size_for_buffer(void);

/*!
 * \brief Write instrumentation data to the given buffer.
 *
 * \pre \c Buffer is the start of a buffer at least as big as \a
 * __llvm_profile_get_size_for_buffer().
 */
int __llvm_profile_write_buffer(char *Buffer);

const __llvm_profile_data *__llvm_profile_begin_data(void);
const __llvm_profile_data *__llvm_profile_end_data(void);
const char *__llvm_profile_begin_names(void);
const char *__llvm_profile_end_names(void);
uint64_t *__llvm_profile_begin_counters(void);
uint64_t *__llvm_profile_end_counters(void);
ValueProfNode *__llvm_profile_begin_vnodes();
ValueProfNode *__llvm_profile_end_vnodes();

/*!
 * \brief Clear profile counters to zero.
 *
 */
void __llvm_profile_reset_counters(void);

/*!
 * \brief Merge profile data from buffer.
 *
 * Read profile data form buffer \p Profile  and merge with
 * in-process profile counters. The client is expected to
 * have checked or already knows the profile data in the
 * buffer matches the in-process counter structure before
 * calling it.
 */
void __llvm_profile_merge_from_buffer(const char *Profile, uint64_t Size);

/*! \brief Check if profile in buffer matches the current binary.
 *
 *  Returns 0 (success) if the profile data in buffer \p Profile with size
 *  \p Size was generated by the same binary and therefore matches
 *  structurally the in-process counters. If the profile data in buffer is
 *  not compatible, the interface returns 1 (failure).
 */
int __llvm_profile_check_compatibility(const char *Profile,
                                       uint64_t Size);

/*!
 * \brief Counts the number of times a target value is seen.
 *
 * Records the target value for the CounterIndex if not seen before. Otherwise,
 * increments the counter associated w/ the target value.
 * void __llvm_profile_instrument_target(uint64_t TargetValue, void *Data,
 *                                       uint32_t CounterIndex);
 */
void INSTR_PROF_VALUE_PROF_FUNC(
#define VALUE_PROF_FUNC_PARAM(ArgType, ArgName, ArgLLVMType) ArgType ArgName
#include "InstrProfData.inc"
    );

void __llvm_profile_instrument_target_value(uint64_t TargetValue, void *Data,
                                            uint32_t CounterIndex,
                                            uint64_t CounterValue);

/*!
 * \brief Write instrumentation data to the current file.
 *
 * Writes to the file with the last name given to \a *
 * __llvm_profile_set_filename(),
 * or if it hasn't been called, the \c LLVM_PROFILE_FILE environment variable,
 * or if that's not set, the last name set to INSTR_PROF_PROFILE_NAME_VAR,
 * or if that's not set,  \c "default.profraw".
 */
int __llvm_profile_write_file(void);

/*!
 * \brief this is a wrapper interface to \c __llvm_profile_write_file.
 * After this interface is invoked, a arleady dumped flag will be set
 * so that profile won't be dumped again during program exit. 
 * Invocation of interface __llvm_profile_reset_counters will clear
 * the flag. This interface is designed to be used to collect profile
 * data from user selected hot regions. The use model is
 *      __llvm_profile_reset_counters();
 *      ... hot region 1
 *      __llvm_profile_dump();
 *      .. some other code
 *      __llvm_profile_reset_counters();
 *       ... hot region 2
 *      __llvm_profile_dump();
 *
 *  It is expected that on-line profile merging is on with \c %m specifier
 *  used in profile filename . If merging is  not turned on, user is expected
 *  to invoke __llvm_profile_set_filename  to specify different profile names
 *  for different regions before dumping to avoid profile write clobbering.
 */
int __llvm_profile_dump(void);

/*!
 * \brief Set the filename for writing instrumentation data.
 *
 * Sets the filename to be used for subsequent calls to
 * \a __llvm_profile_write_file().
 *
 * \c Name is not copied, so it must remain valid.  Passing NULL resets the
 * filename logic to the default behaviour.
 */
void __llvm_profile_set_filename(const char *Name);

/*! \brief Register to write instrumentation data to file at exit. */
int __llvm_profile_register_write_file_atexit(void);

/*! \brief Initialize file handling. */
void __llvm_profile_initialize_file(void);

/*!
 * \brief Return path prefix (excluding the base filename) of the profile data.
 * This is useful for users using \c -fprofile-generate=./path_prefix who do
 * not care about the default raw profile name. It is also useful to collect
 * more than more profile data files dumped in the same directory (Online
 * merge mode is turned on for instrumented programs with shared libs).
 * Side-effect: this API call will invoke malloc with dynamic memory allocation.
 */
const char *__llvm_profile_get_path_prefix();

/*!
 * \brief Return filename (including path) of the profile data. Note that if the
 * user calls __llvm_profile_set_filename later after invoking this interface,
 * the actual file name may differ from what is returned here.
 * Side-effect: this API call will invoke malloc with dynamic memory allocation.
 */
const char *__llvm_profile_get_filename();

/*! \brief Get the magic token for the file format. */
uint64_t __llvm_profile_get_magic(void);

/*! \brief Get the version of the file format. */
uint64_t __llvm_profile_get_version(void);

/*! \brief Get the number of entries in the profile data section. */
uint64_t __llvm_profile_get_data_size(const __llvm_profile_data *Begin,
                                      const __llvm_profile_data *End);

/*!
 * This variable is defined in InstrProfilingRuntime.cc as a hidden
 * symbol. Its main purpose is to enable profile runtime user to
 * bypass runtime initialization code -- if the client code explicitly
 * define this variable, then InstProfileRuntime.o won't be linked in.
 * Note that this variable's visibility needs to be hidden so that the
 * definition of this variable in an instrumented shared library won't
 * affect runtime initialization decision of the main program.
 *  __llvm_profile_profile_runtime. */
COMPILER_RT_VISIBILITY extern int INSTR_PROF_PROFILE_RUNTIME_VAR;

/*!
 * This variable is defined in InstrProfiling.c. Its main purpose is to
 * encode the raw profile version value and other format related information
 * such as whether the profile is from IR based instrumentation. The variable
 * is defined as weak so that compiler can emit an overriding definition
 * depending on user option.  Since we don't support mixing FE and IR based
 * data in the same raw profile data file (in other words, shared libs and
 * main program are expected to be instrumented in the same way), there is
 * no need for this variable to be hidden.
 */
extern uint64_t INSTR_PROF_RAW_VERSION_VAR; /* __llvm_profile_raw_version */

/*!
 * This variable is a weak symbol defined in InstrProfiling.c. It allows
 * compiler instrumentation to provide overriding definition with value
 * from compiler command line. This variable has default visibility.
 */
extern char INSTR_PROF_PROFILE_NAME_VAR[1]; /* __llvm_profile_filename. */

#endif /* PROFILE_INSTRPROFILING_H_ */