llvm/compiler-rt/lib/profile/InstrProfilingBuffer.c

/*===- InstrProfilingBuffer.c - Write instrumentation to a memory buffer --===*\
|*
|* 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
|*
\*===----------------------------------------------------------------------===*/

// Note: This is linked into the Darwin kernel, and must remain compatible
// with freestanding compilation. See `darwin_add_builtin_libraries`.

#include "InstrProfiling.h"
#include "InstrProfilingInternal.h"
#include "InstrProfilingPort.h"

/* When continuous mode is enabled (%c), this parameter is set to 1.
 *
 * This parameter is defined here in InstrProfilingBuffer.o, instead of in
 * InstrProfilingFile.o, to sequester all libc-dependent code in
 * InstrProfilingFile.o. The test `instrprof-without-libc` will break if this
 * layering is violated. */
static int ContinuouslySyncProfile = …;

/* The system page size. Only valid when non-zero. If 0, the page size is
 * unavailable. */
static unsigned PageSize = …;

COMPILER_RT_VISIBILITY int __llvm_profile_is_continuous_mode_enabled(void) { … }

COMPILER_RT_VISIBILITY void __llvm_profile_enable_continuous_mode(void) { … }

COMPILER_RT_VISIBILITY void __llvm_profile_disable_continuous_mode(void) { … }

COMPILER_RT_VISIBILITY void __llvm_profile_set_page_size(unsigned PS) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_size_for_buffer(void) { … }

// NOTE: Caller should guarantee that `Begin` and `End` specifies a half-open
// interval [Begin, End). Namely, `End` is one-byte past the end of the array.
COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_num_data(const __llvm_profile_data *Begin,
                                     const __llvm_profile_data *End) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_data_size(const __llvm_profile_data *Begin,
                                      const __llvm_profile_data *End) { … }

// Counts the number of `VTableProfData` elements within the range of [Begin,
// End). Caller should guarantee that End points to one byte past the inclusive
// range.
// FIXME: Add a compiler-rt test to make sure the number of vtables in the
// raw profile is the same as the number of vtable elements in the instrumented
// binary.
COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_num_vtable(const VTableProfData *Begin,
                                       const VTableProfData *End) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_vtable_section_size(const VTableProfData *Begin,
                                                const VTableProfData *End) { … }

COMPILER_RT_VISIBILITY size_t __llvm_profile_counter_entry_size(void) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_num_counters(const char *Begin, const char *End) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_counters_size(const char *Begin, const char *End) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_num_bitmap_bytes(const char *Begin,
                                             const char *End) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_name_size(const char *Begin, const char *End) { … }

/// Calculate the number of padding bytes needed to add to \p Offset in order
/// for (\p Offset + Padding) to be page-aligned.
static uint64_t calculateBytesNeededToPageAlign(uint64_t Offset) { … }

static int needsCounterPadding(void) { … }

COMPILER_RT_VISIBILITY
int __llvm_profile_get_padding_sizes_for_counters(
    uint64_t DataSize, uint64_t CountersSize, uint64_t NumBitmapBytes,
    uint64_t NamesSize, uint64_t VTableSize, uint64_t VNameSize,
    uint64_t *PaddingBytesBeforeCounters, uint64_t *PaddingBytesAfterCounters,
    uint64_t *PaddingBytesAfterBitmapBytes, uint64_t *PaddingBytesAfterNames,
    uint64_t *PaddingBytesAfterVTable, uint64_t *PaddingBytesAfterVName) { … }

COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_size_for_buffer_internal(
    const __llvm_profile_data *DataBegin, const __llvm_profile_data *DataEnd,
    const char *CountersBegin, const char *CountersEnd, const char *BitmapBegin,
    const char *BitmapEnd, const char *NamesBegin, const char *NamesEnd,
    const VTableProfData *VTableBegin, const VTableProfData *VTableEnd,
    const char *VNamesBegin, const char *VNamesEnd) { … }

COMPILER_RT_VISIBILITY
void initBufferWriter(ProfDataWriter *BufferWriter, char *Buffer) { … }

COMPILER_RT_VISIBILITY int __llvm_profile_write_buffer(char *Buffer) { … }

COMPILER_RT_VISIBILITY int __llvm_profile_write_buffer_internal(
    char *Buffer, const __llvm_profile_data *DataBegin,
    const __llvm_profile_data *DataEnd, const char *CountersBegin,
    const char *CountersEnd, const char *BitmapBegin, const char *BitmapEnd,
    const char *NamesBegin, const char *NamesEnd) { … }