Split format() out to its own file, add support for formatting

up to three values in one call.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55251 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-08-23 19:48:00 +00:00
parent 0958ab0fd1
commit b2560526d5
2 changed files with 156 additions and 59 deletions

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@ -0,0 +1,155 @@
//===--- Format.h - Efficient printf-style formatting for streams etc -----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the format() function, which can be used with other
// LLVM subsystems to provide printf-style formatting. This gives all the power
// and risk of printf. This can be used like this (with raw_ostreams as an
// example):
//
// OS << "mynumber: " << format("%4.5f", 1234.412) << '\n';
//
// Or if you prefer:
//
// OS << format("mynumber: %4.5f\n", 1234.412);
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FORMAT_H
#define LLVM_SUPPORT_FORMAT_H
#include <cstdio>
#ifdef WIN32
#define snprintf _snprintf
#endif
namespace llvm {
/// format_object_base - This is a helper class used for handling formatted
/// output. It is the abstract base class of a templated derived class.
class format_object_base {
protected:
const char *Fmt;
virtual void home(); // Out of line virtual method.
public:
format_object_base(const char *fmt) : Fmt(fmt) {}
virtual ~format_object_base() {}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const = 0;
};
/// format_object1 - This is a templated helper class used by the format
/// function that captures the object to be formated and the format string. When
/// actually printed, this synthesizes the string into a temporary buffer
/// provided and returns whether or not it is big enough.
template <typename T>
class format_object1 : public format_object_base {
T Val;
public:
format_object1(const char *fmt, const T &val)
: format_object_base(fmt), Val(val) {
}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const {
int N = snprintf(Buffer, BufferSize-1, Fmt, Val);
if (N < 0) // VC++ and old GlibC return negative on overflow.
return BufferSize*2;
if (unsigned(N) >= BufferSize-1)// Other impls yield number of bytes needed.
return N+1;
// If N is positive and <= BufferSize-1, then the string fit, yay.
return N;
}
};
/// format_object2 - This is a templated helper class used by the format
/// function that captures the object to be formated and the format string. When
/// actually printed, this synthesizes the string into a temporary buffer
/// provided and returns whether or not it is big enough.
template <typename T1, typename T2>
class format_object2 : public format_object_base {
T1 Val1;
T2 Val2;
public:
format_object2(const char *fmt, const T1 &val1, const T2 &val2)
: format_object_base(fmt), Val1(val1), Val2(val2) {
}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const {
int N = snprintf(Buffer, BufferSize-1, Fmt, Val1, Val2);
if (N < 0) // VC++ and old GlibC return negative on overflow.
return BufferSize*2;
if (unsigned(N) >= BufferSize-1)// Other impls yield number of bytes needed.
return N+1;
// If N is positive and <= BufferSize-1, then the string fit, yay.
return N;
}
};
/// format_object3 - This is a templated helper class used by the format
/// function that captures the object to be formated and the format string. When
/// actually printed, this synthesizes the string into a temporary buffer
/// provided and returns whether or not it is big enough.
template <typename T1, typename T2, typename T3>
class format_object3 : public format_object_base {
T1 Val1;
T2 Val2;
T3 Val3;
public:
format_object3(const char *fmt, const T1 &val1, const T2 &val2,const T3 &val3)
: format_object_base(fmt), Val1(val1), Val2(val2), Val3(val3) {
}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const {
int N = snprintf(Buffer, BufferSize-1, Fmt, Val1, Val2, Val3);
if (N < 0) // VC++ and old GlibC return negative on overflow.
return BufferSize*2;
if (unsigned(N) >= BufferSize-1)// Other impls yield number of bytes needed.
return N+1;
// If N is positive and <= BufferSize-1, then the string fit, yay.
return N;
}
};
/// format - This is a helper function that is used to produce formatted output.
/// This is typically used like: OS << format("%0.4f", myfloat) << '\n';
template <typename T>
inline format_object1<T> format(const char *Fmt, const T &Val) {
return format_object1<T>(Fmt, Val);
}
/// format - This is a helper function that is used to produce formatted output.
/// This is typically used like: OS << format("%0.4f", myfloat) << '\n';
template <typename T1, typename T2>
inline format_object2<T1, T2> format(const char *Fmt, const T1 &Val1,
const T2 &Val2) {
return format_object2<T1, T2>(Fmt, Val1, Val2);
}
/// format - This is a helper function that is used to produce formatted output.
/// This is typically used like: OS << format("%0.4f", myfloat) << '\n';
template <typename T1, typename T2, typename T3>
inline format_object3<T1, T2, T3> format(const char *Fmt, const T1 &Val1,
const T2 &Val2, const T3 &Val3) {
return format_object3<T1, T2, T3>(Fmt, Val1, Val2, Val3);
}
} // end namespace llvm
#endif

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@ -17,7 +17,6 @@
#include "llvm/ADT/StringExtras.h"
#include <cassert>
#include <cstring>
#include <cstdio>
#include <string>
#include <iosfwd>
@ -112,7 +111,7 @@ public:
raw_ostream &write(const char *Ptr, unsigned Size);
// Formatted output, see the format() function below.
// Formatted output, see the format() function in Support/Format.h.
raw_ostream &operator<<(const format_object_base &Fmt);
//===--------------------------------------------------------------------===//
@ -138,63 +137,6 @@ private:
virtual void handle();
};
//===----------------------------------------------------------------------===//
// Formatted Output
//===----------------------------------------------------------------------===//
/// format_object_base - This is a helper class used for handling formatted
/// output. It is the abstract base class of a templated derived class.
class format_object_base {
protected:
const char *Fmt;
virtual void home(); // Out of line virtual method.
public:
format_object_base(const char *fmt) : Fmt(fmt) {}
virtual ~format_object_base() {}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const = 0;
};
/// format_object - This is a templated helper class used by the format function
/// that captures the object to be formated and the format string. When
/// actually printed, this synthesizes the string into a temporary buffer
/// provided and returns whether or not it is big enough.
template <typename T>
class format_object : public format_object_base {
T Val;
public:
format_object(const char *fmt, const T &val)
: format_object_base(fmt), Val(val) {
}
/// print - Format the object into the specified buffer. On success, this
/// returns the length of the formatted string. If the buffer is too small,
/// this returns a length to retry with, which will be larger than BufferSize.
virtual unsigned print(char *Buffer, unsigned BufferSize) const {
#ifdef WIN32
int N = _snprintf(Buffer, BufferSize-1, Fmt, Val);
#else
int N = snprintf(Buffer, BufferSize-1, Fmt, Val);
#endif
if (N < 0) // VC++ and old GlibC return negative on overflow.
return BufferSize*2;
if (unsigned(N) >= BufferSize-1)// Other impls yield number of bytes needed.
return N+1;
// If N is positive and <= BufferSize-1, then the string fit, yay.
return N;
}
};
/// format - This is a helper function that is used to produce formatted output.
/// This is typically used like: OS << format("%0.4f", myfloat) << '\n';
template <typename T>
inline format_object<T> format(const char *Fmt, const T &Val) {
return format_object<T>(Fmt, Val);
}
//===----------------------------------------------------------------------===//
// File Output Streams
//===----------------------------------------------------------------------===//