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

574 lines
16 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/Support/Format.h"
#include "llvm/System/Program.h"
#include "llvm/System/Process.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
#include <sys/stat.h>
#include <sys/types.h>
#if defined(HAVE_UNISTD_H)
# include <unistd.h>
#endif
#if defined(HAVE_FCNTL_H)
# include <fcntl.h>
#endif
#if defined(_MSC_VER)
#include <io.h>
#include <fcntl.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
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;
// If there are any pending errors, report them now. Clients wishing
// to avoid llvm_report_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 (Error)
llvm_report_error("IO failure on output stream.");
}
// 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() {
// 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 == 0 && Size == 0) ||
(Mode != Unbuffered && BufferStart && Size >= 64)) &&
"stream must be unbuffered, or have >= 64 bytes of buffer");
// 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) {
// Zero is a special case.
if (N == 0)
return *this << '0';
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
*--CurPtr = '0' + char(N % 10);
N /= 10;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long N) {
if (N < 0) {
*this << '-';
N = -N;
}
return this->operator<<(static_cast<unsigned long>(N));
}
raw_ostream &raw_ostream::operator<<(unsigned long long N) {
// Output using 32-bit div/mod when possible.
if (N == static_cast<unsigned long>(N))
return this->operator<<(static_cast<unsigned long>(N));
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
*--CurPtr = '0' + char(N % 10);
N /= 10;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(long long N) {
if (N < 0) {
*this << '-';
N = -N;
}
return this->operator<<(static_cast<unsigned long long>(N));
}
raw_ostream &raw_ostream::write_hex(unsigned long long N) {
// Zero is a special case.
if (N == 0)
return *this << '0';
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
uintptr_t x = N % 16;
*--CurPtr = (x < 10 ? '0' + x : 'a' + x - 10);
N /= 16;
}
return write(CurPtr, EndPtr-CurPtr);
}
raw_ostream &raw_ostream::operator<<(const void *P) {
*this << '0' << 'x';
return write_hex((uintptr_t) P);
}
raw_ostream &raw_ostream::operator<<(double N) {
this->operator<<(ftostr(N));
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 (BUILTIN_EXPECT(OutBufCur >= OutBufEnd, false)) {
if (BUILTIN_EXPECT(!OutBufStart, false)) {
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 (BUILTIN_EXPECT(OutBufCur+Size > OutBufEnd, false)) {
if (BUILTIN_EXPECT(!OutBufStart, false)) {
if (BufferMode == Unbuffered) {
write_impl(Ptr, Size);
return *this;
}
// Set up a buffer and start over.
SetBuffered();
return write(Ptr, Size);
}
// Write out the data in buffer-sized blocks until the remainder
// fits within the buffer.
do {
size_t NumBytes = OutBufEnd - OutBufCur;
copy_to_buffer(Ptr, NumBytes);
flush_nonempty();
Ptr += NumBytes;
Size -= NumBytes;
} while (OutBufCur+Size > OutBufEnd);
}
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]; // FALL THROUGH
case 3: OutBufCur[2] = Ptr[2]; // FALL THROUGH
case 2: OutBufCur[1] = Ptr[1]; // FALL THROUGH
case 1: OutBufCur[0] = Ptr[0]; // FALL THROUGH
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 (1) {
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;
}
}
/// 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
//===----------------------------------------------------------------------===//
/// raw_fd_ostream - Open the specified file for writing. If an error
/// occurs, information about the error is put into ErrorInfo, and the
/// stream should be immediately destroyed; the string will be empty
/// if no error occurred.
raw_fd_ostream::raw_fd_ostream(const char *Filename, std::string &ErrorInfo,
unsigned Flags) : pos(0) {
// Verify that we don't have both "append" and "excl".
assert((!(Flags & F_Excl) || !(Flags & F_Append)) &&
"Cannot specify both 'excl' and 'append' file creation flags!");
ErrorInfo.clear();
// Handle "-" as stdout.
if (Filename[0] == '-' && Filename[1] == 0) {
FD = STDOUT_FILENO;
// If user requested binary then put stdout into binary mode if
// possible.
if (Flags & F_Binary)
sys::Program::ChangeStdoutToBinary();
ShouldClose = false;
return;
}
int OpenFlags = O_WRONLY|O_CREAT;
#ifdef O_BINARY
if (Flags & F_Binary)
OpenFlags |= O_BINARY;
#endif
if (Flags & F_Append)
OpenFlags |= O_APPEND;
else
OpenFlags |= O_TRUNC;
if (Flags & F_Excl)
OpenFlags |= O_EXCL;
FD = open(Filename, OpenFlags, 0664);
if (FD < 0) {
ErrorInfo = "Error opening output file '" + std::string(Filename) + "'";
ShouldClose = false;
} else {
ShouldClose = true;
}
}
raw_fd_ostream::~raw_fd_ostream() {
if (FD < 0) return;
flush();
if (ShouldClose)
if (::close(FD) != 0)
error_detected();
}
void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
assert (FD >= 0 && "File already closed.");
pos += Size;
if (::write(FD, Ptr, Size) != (ssize_t) Size)
error_detected();
}
void raw_fd_ostream::close() {
assert (ShouldClose);
ShouldClose = false;
flush();
if (::close(FD) != 0)
error_detected();
FD = -1;
}
uint64_t raw_fd_ostream::seek(uint64_t off) {
flush();
pos = ::lseek(FD, off, SEEK_SET);
if (pos != off)
error_detected();
return pos;
}
size_t raw_fd_ostream::preferred_buffer_size() {
#if !defined(_MSC_VER) && !defined(__MINGW32__) // Windows has no st_blksize.
assert(FD >= 0 && "File not yet open!");
struct stat statbuf;
if (fstat(FD, &statbuf) == 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;
}
error_detected();
#endif
return raw_ostream::preferred_buffer_size();
}
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;
}
bool raw_fd_ostream::is_displayed() const {
return sys::Process::FileDescriptorIsDisplayed(FD);
}
//===----------------------------------------------------------------------===//
// raw_stdout/err_ostream
//===----------------------------------------------------------------------===//
// Set buffer settings to model stdout and stderr behavior.
// Set standard error to be unbuffered by default.
raw_stdout_ostream::raw_stdout_ostream():raw_fd_ostream(STDOUT_FILENO, false) {}
raw_stderr_ostream::raw_stderr_ostream():raw_fd_ostream(STDERR_FILENO, false,
true) {}
// An out of line virtual method to provide a home for the class vtable.
void raw_stdout_ostream::handle() {}
void raw_stderr_ostream::handle() {}
/// outs() - This returns a reference to a raw_ostream for standard output.
/// Use it like: outs() << "foo" << "bar";
raw_ostream &llvm::outs() {
static raw_stdout_ostream S;
return S;
}
/// errs() - This returns a reference to a raw_ostream for standard error.
/// Use it like: errs() << "foo" << "bar";
raw_ostream &llvm::errs() {
static raw_stderr_ostream S;
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
//===----------------------------------------------------------------------===//
// The raw_svector_ostream implementation uses the SmallVector itself as the
// buffer for the raw_ostream. We guarantee that the raw_ostream buffer is
// always pointing past the end of the vector, but within the vector
// capacity. This allows raw_ostream to write directly into the correct place,
// and we only need to set the vector size when the data is flushed.
raw_svector_ostream::raw_svector_ostream(SmallVectorImpl<char> &O) : OS(O) {
// Set up the initial external buffer. We make sure that the buffer has at
// least 128 bytes free; raw_ostream itself only requires 64, but we want to
// make sure that we don't grow the buffer unnecessarily on destruction (when
// the data is flushed). See the FIXME below.
OS.reserve(OS.size() + 128);
SetBuffer(OS.end(), OS.capacity() - OS.size());
}
raw_svector_ostream::~raw_svector_ostream() {
// FIXME: Prevent resizing during this flush().
flush();
}
void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
assert(Ptr == OS.end() && OS.size() + Size <= OS.capacity() &&
"Invalid write_impl() call!");
// We don't need to copy the bytes, just commit the bytes to the
// SmallVector.
OS.set_size(OS.size() + Size);
// Grow the vector if necessary.
if (OS.capacity() - OS.size() < 64)
OS.reserve(OS.capacity() * 2);
// Update the buffer position.
SetBuffer(OS.end(), OS.capacity() - OS.size());
}
uint64_t raw_svector_ostream::current_pos() { return OS.size(); }
StringRef raw_svector_ostream::str() {
flush();
return StringRef(OS.begin(), OS.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() {
return 0;
}