llvm-project/llvm/lib/Support/raw_ostream.cpp

672 lines
20 KiB
C++

//===--- raw_ostream.cpp - Implement the raw_ostream classes --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements support for bulk buffered stream output.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/NativeFormatting.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include <algorithm>
#include <cctype>
#include <cerrno>
#include <cstdio>
#include <iterator>
#include <sys/stat.h>
#include <system_error>
// <fcntl.h> may provide O_BINARY.
#if defined(HAVE_FCNTL_H)
# include <fcntl.h>
#endif
#if defined(HAVE_UNISTD_H)
# include <unistd.h>
#endif
#if defined(HAVE_SYS_UIO_H) && defined(HAVE_WRITEV)
# include <sys/uio.h>
#endif
#if defined(__CYGWIN__)
#include <io.h>
#endif
#if defined(_MSC_VER)
#include <io.h>
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif
#endif
#ifdef LLVM_ON_WIN32
#include "Windows/WindowsSupport.h"
#endif
using namespace llvm;
raw_ostream::~raw_ostream() {
// raw_ostream's subclasses should take care to flush the buffer
// in their destructors.
assert(OutBufCur == OutBufStart &&
"raw_ostream destructor called with non-empty buffer!");
if (BufferMode == InternalBuffer)
delete [] OutBufStart;
}
// An out of line virtual method to provide a home for the class vtable.
void raw_ostream::handle() {}
size_t raw_ostream::preferred_buffer_size() const {
// BUFSIZ is intended to be a reasonable default.
return BUFSIZ;
}
void raw_ostream::SetBuffered() {
// Ask the subclass to determine an appropriate buffer size.
if (size_t Size = preferred_buffer_size())
SetBufferSize(Size);
else
// It may return 0, meaning this stream should be unbuffered.
SetUnbuffered();
}
void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
BufferKind Mode) {
assert(((Mode == Unbuffered && !BufferStart && Size == 0) ||
(Mode != Unbuffered && BufferStart && Size != 0)) &&
"stream must be unbuffered or have at least one byte");
// Make sure the current buffer is free of content (we can't flush here; the
// child buffer management logic will be in write_impl).
assert(GetNumBytesInBuffer() == 0 && "Current buffer is non-empty!");
if (BufferMode == InternalBuffer)
delete [] OutBufStart;
OutBufStart = BufferStart;
OutBufEnd = OutBufStart+Size;
OutBufCur = OutBufStart;
BufferMode = Mode;
assert(OutBufStart <= OutBufEnd && "Invalid size!");
}
raw_ostream &raw_ostream::operator<<(unsigned long N) {
write_ulong(*this, N, 0);
return *this;
}
raw_ostream &raw_ostream::operator<<(long N) {
write_long(*this, N, 0);
return *this;
}
raw_ostream &raw_ostream::operator<<(unsigned long long N) {
write_ulonglong(*this, N, 0);
return *this;
}
raw_ostream &raw_ostream::operator<<(long long N) {
write_longlong(*this, N, 0);
return *this;
}
raw_ostream &raw_ostream::write_hex(unsigned long long N) {
llvm::write_hex(*this, N, 0, false, false);
return *this;
}
raw_ostream &raw_ostream::write_escaped(StringRef Str,
bool UseHexEscapes) {
for (unsigned char c : Str) {
switch (c) {
case '\\':
*this << '\\' << '\\';
break;
case '\t':
*this << '\\' << 't';
break;
case '\n':
*this << '\\' << 'n';
break;
case '"':
*this << '\\' << '"';
break;
default:
if (std::isprint(c)) {
*this << c;
break;
}
// Write out the escaped representation.
if (UseHexEscapes) {
*this << '\\' << 'x';
*this << hexdigit((c >> 4 & 0xF));
*this << hexdigit((c >> 0) & 0xF);
} else {
// Always use a full 3-character octal escape.
*this << '\\';
*this << char('0' + ((c >> 6) & 7));
*this << char('0' + ((c >> 3) & 7));
*this << char('0' + ((c >> 0) & 7));
}
}
}
return *this;
}
raw_ostream &raw_ostream::operator<<(const void *P) {
llvm::write_hex(*this, (uintptr_t)P, 0, false, true);
return *this;
}
raw_ostream &raw_ostream::operator<<(double N) {
llvm::write_double(*this, N, 0, 0, FloatStyle::Exponent);
return *this;
}
void raw_ostream::flush_nonempty() {
assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
size_t Length = OutBufCur - OutBufStart;
OutBufCur = OutBufStart;
write_impl(OutBufStart, Length);
}
raw_ostream &raw_ostream::write(unsigned char C) {
// Group exceptional cases into a single branch.
if (LLVM_UNLIKELY(OutBufCur >= OutBufEnd)) {
if (LLVM_UNLIKELY(!OutBufStart)) {
if (BufferMode == Unbuffered) {
write_impl(reinterpret_cast<char*>(&C), 1);
return *this;
}
// Set up a buffer and start over.
SetBuffered();
return write(C);
}
flush_nonempty();
}
*OutBufCur++ = C;
return *this;
}
raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
// Group exceptional cases into a single branch.
if (LLVM_UNLIKELY(size_t(OutBufEnd - OutBufCur) < Size)) {
if (LLVM_UNLIKELY(!OutBufStart)) {
if (BufferMode == Unbuffered) {
write_impl(Ptr, Size);
return *this;
}
// Set up a buffer and start over.
SetBuffered();
return write(Ptr, Size);
}
size_t NumBytes = OutBufEnd - OutBufCur;
// If the buffer is empty at this point we have a string that is larger
// than the buffer. Directly write the chunk that is a multiple of the
// preferred buffer size and put the remainder in the buffer.
if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
assert(NumBytes != 0 && "undefined behavior");
size_t BytesToWrite = Size - (Size % NumBytes);
write_impl(Ptr, BytesToWrite);
size_t BytesRemaining = Size - BytesToWrite;
if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
// Too much left over to copy into our buffer.
return write(Ptr + BytesToWrite, BytesRemaining);
}
copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
return *this;
}
// We don't have enough space in the buffer to fit the string in. Insert as
// much as possible, flush and start over with the remainder.
copy_to_buffer(Ptr, NumBytes);
flush_nonempty();
return write(Ptr + NumBytes, Size - NumBytes);
}
copy_to_buffer(Ptr, Size);
return *this;
}
void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
assert(Size <= size_t(OutBufEnd - OutBufCur) && "Buffer overrun!");
// Handle short strings specially, memcpy isn't very good at very short
// strings.
switch (Size) {
case 4: OutBufCur[3] = Ptr[3]; LLVM_FALLTHROUGH;
case 3: OutBufCur[2] = Ptr[2]; LLVM_FALLTHROUGH;
case 2: OutBufCur[1] = Ptr[1]; LLVM_FALLTHROUGH;
case 1: OutBufCur[0] = Ptr[0]; LLVM_FALLTHROUGH;
case 0: break;
default:
memcpy(OutBufCur, Ptr, Size);
break;
}
OutBufCur += Size;
}
// Formatted output.
raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
// If we have more than a few bytes left in our output buffer, try
// formatting directly onto its end.
size_t NextBufferSize = 127;
size_t BufferBytesLeft = OutBufEnd - OutBufCur;
if (BufferBytesLeft > 3) {
size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
// Common case is that we have plenty of space.
if (BytesUsed <= BufferBytesLeft) {
OutBufCur += BytesUsed;
return *this;
}
// Otherwise, we overflowed and the return value tells us the size to try
// again with.
NextBufferSize = BytesUsed;
}
// If we got here, we didn't have enough space in the output buffer for the
// string. Try printing into a SmallVector that is resized to have enough
// space. Iterate until we win.
SmallVector<char, 128> V;
while (true) {
V.resize(NextBufferSize);
// Try formatting into the SmallVector.
size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
// If BytesUsed fit into the vector, we win.
if (BytesUsed <= NextBufferSize)
return write(V.data(), BytesUsed);
// Otherwise, try again with a new size.
assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
NextBufferSize = BytesUsed;
}
}
raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
unsigned Len = FS.Str.size();
int PadAmount = FS.Width - Len;
if (FS.RightJustify && (PadAmount > 0))
this->indent(PadAmount);
this->operator<<(FS.Str);
if (!FS.RightJustify && (PadAmount > 0))
this->indent(PadAmount);
return *this;
}
raw_ostream &raw_ostream::operator<<(const FormattedNumber &FN) {
if (FN.Hex) {
llvm::write_hex(*this, FN.HexValue, FN.Width, FN.Upper, FN.HexPrefix);
} else {
llvm::write_longlong(*this, FN.DecValue, FN.Width);
}
return *this;
}
/// indent - Insert 'NumSpaces' spaces.
raw_ostream &raw_ostream::indent(unsigned NumSpaces) {
static const char Spaces[] = " "
" "
" ";
// Usually the indentation is small, handle it with a fastpath.
if (NumSpaces < array_lengthof(Spaces))
return write(Spaces, NumSpaces);
while (NumSpaces) {
unsigned NumToWrite = std::min(NumSpaces,
(unsigned)array_lengthof(Spaces)-1);
write(Spaces, NumToWrite);
NumSpaces -= NumToWrite;
}
return *this;
}
//===----------------------------------------------------------------------===//
// Formatted Output
//===----------------------------------------------------------------------===//
// Out of line virtual method.
void format_object_base::home() {
}
//===----------------------------------------------------------------------===//
// raw_fd_ostream
//===----------------------------------------------------------------------===//
static int getFD(StringRef Filename, std::error_code &EC,
sys::fs::OpenFlags Flags) {
// Handle "-" as stdout. Note that when we do this, we consider ourself
// the owner of stdout. This means that we can do things like close the
// file descriptor when we're done and set the "binary" flag globally.
if (Filename == "-") {
EC = std::error_code();
// If user requested binary then put stdout into binary mode if
// possible.
if (!(Flags & sys::fs::F_Text))
sys::ChangeStdoutToBinary();
return STDOUT_FILENO;
}
int FD;
EC = sys::fs::openFileForWrite(Filename, FD, Flags);
if (EC)
return -1;
return FD;
}
raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
sys::fs::OpenFlags Flags)
: raw_fd_ostream(getFD(Filename, EC, Flags), true) {}
/// FD is the file descriptor that this writes to. If ShouldClose is true, this
/// closes the file when the stream is destroyed.
raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered)
: raw_pwrite_stream(unbuffered), FD(fd), ShouldClose(shouldClose),
Error(false) {
if (FD < 0 ) {
ShouldClose = false;
return;
}
// Get the starting position.
off_t loc = ::lseek(FD, 0, SEEK_CUR);
#ifdef LLVM_ON_WIN32
// MSVCRT's _lseek(SEEK_CUR) doesn't return -1 for pipes.
sys::fs::file_status Status;
std::error_code EC = status(FD, Status);
SupportsSeeking = !EC && Status.type() == sys::fs::file_type::regular_file;
#else
SupportsSeeking = loc != (off_t)-1;
#endif
if (!SupportsSeeking)
pos = 0;
else
pos = static_cast<uint64_t>(loc);
}
raw_fd_ostream::~raw_fd_ostream() {
if (FD >= 0) {
flush();
if (ShouldClose && sys::Process::SafelyCloseFileDescriptor(FD))
error_detected();
}
#ifdef __MINGW32__
// On mingw, global dtors should not call exit().
// report_fatal_error() invokes exit(). We know report_fatal_error()
// might not write messages to stderr when any errors were detected
// on FD == 2.
if (FD == 2) return;
#endif
// If there are any pending errors, report them now. Clients wishing
// to avoid report_fatal_error calls should check for errors with
// has_error() and clear the error flag with clear_error() before
// destructing raw_ostream objects which may have errors.
if (has_error())
report_fatal_error("IO failure on output stream.", /*GenCrashDiag=*/false);
}
void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
assert(FD >= 0 && "File already closed.");
pos += Size;
#ifndef LLVM_ON_WIN32
bool ShouldWriteInChunks = false;
#else
// Writing a large size of output to Windows console returns ENOMEM. It seems
// that, prior to Windows 8, WriteFile() is redirecting to WriteConsole(), and
// the latter has a size limit (66000 bytes or less, depending on heap usage).
bool ShouldWriteInChunks = !!::_isatty(FD) && !RunningWindows8OrGreater();
#endif
do {
size_t ChunkSize = Size;
if (ChunkSize > 32767 && ShouldWriteInChunks)
ChunkSize = 32767;
ssize_t ret = ::write(FD, Ptr, ChunkSize);
if (ret < 0) {
// If it's a recoverable error, swallow it and retry the write.
//
// Ideally we wouldn't ever see EAGAIN or EWOULDBLOCK here, since
// raw_ostream isn't designed to do non-blocking I/O. However, some
// programs, such as old versions of bjam, have mistakenly used
// O_NONBLOCK. For compatibility, emulate blocking semantics by
// spinning until the write succeeds. If you don't want spinning,
// don't use O_NONBLOCK file descriptors with raw_ostream.
if (errno == EINTR || errno == EAGAIN
#ifdef EWOULDBLOCK
|| errno == EWOULDBLOCK
#endif
)
continue;
// Otherwise it's a non-recoverable error. Note it and quit.
error_detected();
break;
}
// The write may have written some or all of the data. Update the
// size and buffer pointer to reflect the remainder that needs
// to be written. If there are no bytes left, we're done.
Ptr += ret;
Size -= ret;
} while (Size > 0);
}
void raw_fd_ostream::close() {
assert(ShouldClose);
ShouldClose = false;
flush();
if (sys::Process::SafelyCloseFileDescriptor(FD))
error_detected();
FD = -1;
}
uint64_t raw_fd_ostream::seek(uint64_t off) {
assert(SupportsSeeking && "Stream does not support seeking!");
flush();
pos = ::lseek(FD, off, SEEK_SET);
if (pos == (uint64_t)-1)
error_detected();
return pos;
}
void raw_fd_ostream::pwrite_impl(const char *Ptr, size_t Size,
uint64_t Offset) {
uint64_t Pos = tell();
seek(Offset);
write(Ptr, Size);
seek(Pos);
}
size_t raw_fd_ostream::preferred_buffer_size() const {
#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__minix)
// Windows and Minix have no st_blksize.
assert(FD >= 0 && "File not yet open!");
struct stat statbuf;
if (fstat(FD, &statbuf) != 0)
return 0;
// If this is a terminal, don't use buffering. Line buffering
// would be a more traditional thing to do, but it's not worth
// the complexity.
if (S_ISCHR(statbuf.st_mode) && isatty(FD))
return 0;
// Return the preferred block size.
return statbuf.st_blksize;
#else
return raw_ostream::preferred_buffer_size();
#endif
}
raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
bool bg) {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode =
(colors == SAVEDCOLOR) ? sys::Process::OutputBold(bg)
: sys::Process::OutputColor(colors, bold, bg);
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
raw_ostream &raw_fd_ostream::resetColor() {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode = sys::Process::ResetColor();
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
raw_ostream &raw_fd_ostream::reverseColor() {
if (sys::Process::ColorNeedsFlush())
flush();
const char *colorcode = sys::Process::OutputReverse();
if (colorcode) {
size_t len = strlen(colorcode);
write(colorcode, len);
// don't account colors towards output characters
pos -= len;
}
return *this;
}
bool raw_fd_ostream::is_displayed() const {
return sys::Process::FileDescriptorIsDisplayed(FD);
}
bool raw_fd_ostream::has_colors() const {
return sys::Process::FileDescriptorHasColors(FD);
}
//===----------------------------------------------------------------------===//
// outs(), errs(), nulls()
//===----------------------------------------------------------------------===//
/// outs() - This returns a reference to a raw_ostream for standard output.
/// Use it like: outs() << "foo" << "bar";
raw_ostream &llvm::outs() {
// Set buffer settings to model stdout behavior. Delete the file descriptor
// when the program exits, forcing error detection. This means that if you
// ever call outs(), you can't open another raw_fd_ostream on stdout, as we'll
// close stdout twice and print an error the second time.
std::error_code EC;
static raw_fd_ostream S("-", EC, sys::fs::F_None);
assert(!EC);
return S;
}
/// errs() - This returns a reference to a raw_ostream for standard error.
/// Use it like: errs() << "foo" << "bar";
raw_ostream &llvm::errs() {
// Set standard error to be unbuffered by default.
static raw_fd_ostream S(STDERR_FILENO, false, true);
return S;
}
/// nulls() - This returns a reference to a raw_ostream which discards output.
raw_ostream &llvm::nulls() {
static raw_null_ostream S;
return S;
}
//===----------------------------------------------------------------------===//
// raw_string_ostream
//===----------------------------------------------------------------------===//
raw_string_ostream::~raw_string_ostream() {
flush();
}
void raw_string_ostream::write_impl(const char *Ptr, size_t Size) {
OS.append(Ptr, Size);
}
//===----------------------------------------------------------------------===//
// raw_svector_ostream
//===----------------------------------------------------------------------===//
uint64_t raw_svector_ostream::current_pos() const { return OS.size(); }
void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
OS.append(Ptr, Ptr + Size);
}
void raw_svector_ostream::pwrite_impl(const char *Ptr, size_t Size,
uint64_t Offset) {
memcpy(OS.data() + Offset, Ptr, Size);
}
//===----------------------------------------------------------------------===//
// raw_null_ostream
//===----------------------------------------------------------------------===//
raw_null_ostream::~raw_null_ostream() {
#ifndef NDEBUG
// ~raw_ostream asserts that the buffer is empty. This isn't necessary
// with raw_null_ostream, but it's better to have raw_null_ostream follow
// the rules than to change the rules just for raw_null_ostream.
flush();
#endif
}
void raw_null_ostream::write_impl(const char *Ptr, size_t Size) {
}
uint64_t raw_null_ostream::current_pos() const {
return 0;
}
void raw_null_ostream::pwrite_impl(const char *Ptr, size_t Size,
uint64_t Offset) {}