| //===- Format.h - Efficient printf-style formatting for streams -*- C++ -*-===// |
| // |
| // 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 <cassert> |
| #include <cstdio> |
| #ifdef _MSC_VER |
| // FIXME: This define is wrong: |
| // - _snprintf does not guarantee that trailing null is always added - if |
| // there is no space for null, it does not report any error. |
| // - According to C++ standard, snprintf should be visible in the 'std' |
| // namespace - this define makes this impossible. |
| #define snprintf _snprintf |
| #endif |
| |
| namespace llvm { |
| |
| /// 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. |
| |
| /// Call snprintf() for this object, on the given buffer and size. |
| virtual int snprint(char *Buffer, unsigned BufferSize) const = 0; |
| |
| public: |
| format_object_base(const char *fmt) : Fmt(fmt) {} |
| virtual ~format_object_base() {} |
| |
| /// 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. |
| unsigned print(char *Buffer, unsigned BufferSize) const { |
| assert(BufferSize && "Invalid buffer size!"); |
| |
| // Print the string, leaving room for the terminating null. |
| int N = snprint(Buffer, BufferSize); |
| |
| // VC++ and old GlibC return negative on overflow, just double the size. |
| if (N < 0) |
| return BufferSize * 2; |
| |
| // Other implementations yield number of bytes needed, not including the |
| // final '\0'. |
| if (unsigned(N) >= BufferSize) |
| return N + 1; |
| |
| // Otherwise N is the length of output (not including the final '\0'). |
| return N; |
| } |
| }; |
| |
| /// These are templated helper classes used by the format function that |
| /// capture 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) { |
| } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val); |
| } |
| }; |
| |
| 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) { |
| } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val1, Val2); |
| } |
| }; |
| |
| 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) { |
| } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val1, Val2, Val3); |
| } |
| }; |
| |
| template <typename T1, typename T2, typename T3, typename T4> |
| class format_object4 : public format_object_base { |
| T1 Val1; |
| T2 Val2; |
| T3 Val3; |
| T4 Val4; |
| public: |
| format_object4(const char *fmt, const T1 &val1, const T2 &val2, |
| const T3 &val3, const T4 &val4) |
| : format_object_base(fmt), Val1(val1), Val2(val2), Val3(val3), Val4(val4) { |
| } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val1, Val2, Val3, Val4); |
| } |
| }; |
| |
| template <typename T1, typename T2, typename T3, typename T4, typename T5> |
| class format_object5 : public format_object_base { |
| T1 Val1; |
| T2 Val2; |
| T3 Val3; |
| T4 Val4; |
| T5 Val5; |
| public: |
| format_object5(const char *fmt, const T1 &val1, const T2 &val2, |
| const T3 &val3, const T4 &val4, const T5 &val5) |
| : format_object_base(fmt), Val1(val1), Val2(val2), Val3(val3), Val4(val4), |
| Val5(val5) { |
| } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val1, Val2, Val3, Val4, Val5); |
| } |
| }; |
| |
| template <typename T1, typename T2, typename T3, typename T4, typename T5, |
| typename T6> |
| class format_object6 : public format_object_base { |
| T1 Val1; |
| T2 Val2; |
| T3 Val3; |
| T4 Val4; |
| T5 Val5; |
| T6 Val6; |
| public: |
| format_object6(const char *Fmt, const T1 &Val1, const T2 &Val2, |
| const T3 &Val3, const T4 &Val4, const T5 &Val5, const T6 &Val6) |
| : format_object_base(Fmt), Val1(Val1), Val2(Val2), Val3(Val3), Val4(Val4), |
| Val5(Val5), Val6(Val6) { } |
| |
| int snprint(char *Buffer, unsigned BufferSize) const override { |
| return snprintf(Buffer, BufferSize, Fmt, Val1, Val2, Val3, Val4, Val5, Val6); |
| } |
| }; |
| |
| /// These are helper functions used to produce formatted output. They use |
| /// template type deduction to construct the appropriate instance of the |
| /// format_object class to simplify their construction. |
| /// |
| /// This is typically used like: |
| /// \code |
| /// OS << format("%0.4f", myfloat) << '\n'; |
| /// \endcode |
| |
| template <typename T> |
| inline format_object1<T> format(const char *Fmt, const T &Val) { |
| return format_object1<T>(Fmt, Val); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| template <typename T1, typename T2, typename T3, typename T4> |
| inline format_object4<T1, T2, T3, T4> format(const char *Fmt, const T1 &Val1, |
| const T2 &Val2, const T3 &Val3, |
| const T4 &Val4) { |
| return format_object4<T1, T2, T3, T4>(Fmt, Val1, Val2, Val3, Val4); |
| } |
| |
| template <typename T1, typename T2, typename T3, typename T4, typename T5> |
| inline format_object5<T1, T2, T3, T4, T5> format(const char *Fmt,const T1 &Val1, |
| const T2 &Val2, const T3 &Val3, |
| const T4 &Val4, const T5 &Val5) { |
| return format_object5<T1, T2, T3, T4, T5>(Fmt, Val1, Val2, Val3, Val4, Val5); |
| } |
| |
| template <typename T1, typename T2, typename T3, typename T4, typename T5, |
| typename T6> |
| inline format_object6<T1, T2, T3, T4, T5, T6> |
| format(const char *Fmt, const T1 &Val1, const T2 &Val2, const T3 &Val3, |
| const T4 &Val4, const T5 &Val5, const T6 &Val6) { |
| return format_object6<T1, T2, T3, T4, T5, T6>(Fmt, Val1, Val2, Val3, Val4, |
| Val5, Val6); |
| } |
| |
| } // end namespace llvm |
| |
| #endif |