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

2 files changed, 156 insertions, 59 deletions

diff --git a/include/llvm/Support/Format.h b/include/llvm/Support/Format.h
new file mode 100644
index 0000000000..b08d698358
--- /dev/null
+++ b/include/llvm/Support/Format.h
@@ -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
diff --git a/include/llvm/Support/raw_ostream.h b/include/llvm/Support/raw_ostream.h
index db312f8735..e78cfe8641 100644
--- a/include/llvm/Support/raw_ostream.h
+++ b/include/llvm/Support/raw_ostream.h
@@ -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);
   
   //===--------------------------------------------------------------------===//
@@ -139,63 +138,6 @@ private:
 };
   
 //===----------------------------------------------------------------------===//
-// 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
 //===----------------------------------------------------------------------===//