1 files changed, 237 insertions, 0 deletions
diff --git a/include/llvm/Bytecode/Primitives.h b/include/llvm/Bytecode/Primitives.h
new file mode 100644
index 0000000000..f4b232b368
--- /dev/null
+++ b/include/llvm/Bytecode/Primitives.h
@@ -0,0 +1,237 @@
+//===-- llvm/Bytecode/Primitives.h - Bytecode file format prims --*- C++ -*--=//
+//
+// This header defines some basic functions for reading and writing basic 
+// primitive types to a bytecode stream.
+//
+// Using the routines defined in this file does not require linking to any 
+// libraries, as all of the services are small self contained units that are to
+// be inlined as neccesary.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BYTECODE_PRIMITIVES_H
+#define LLVM_BYTECODE_PRIMITIVES_H
+
+#include "llvm/Tools/DataTypes.h"
+#include <string>
+#include <vector>
+
+//===----------------------------------------------------------------------===//
+//                             Reading Primitives
+//===----------------------------------------------------------------------===//
+
+static inline bool read(const unsigned char *&Buf, const unsigned char *EndBuf,
+			unsigned &Result) {
+  if (Buf+4 > EndBuf) return true;
+#ifdef LITTLE_ENDIAN
+  Result = *(unsigned*)Buf;
+#else
+  Result = Buf[0] | (Buf[1] << 8) | (Buf[2] << 16) | (Buf[3] << 24);
+#endif
+  Buf += 4;
+  return false;
+}
+
+static inline bool read(const unsigned char *&Buf, const unsigned char *EndBuf,
+			uint64_t &Result) {
+  if (Buf+8 > EndBuf) return true;
+
+#ifdef LITTLE_ENDIAN
+  Result = *(uint64_t*)Buf;
+#else
+  Result = Buf[0] | (Buf[1] << 8) | (Buf[2] << 16) | (Buf[3] << 24) |
+    ((uint64_t)(Buf[4] | (Buf[5] << 8) | (Buf[6] << 16) | (Buf[7] << 24)) <<32);
+#endif
+  Buf += 8;
+  return false;
+}
+
+static inline bool read(const unsigned char *&Buf, const unsigned char *EndBuf,
+			int &Result) {
+  return read(Buf, EndBuf, (unsigned &)Result);
+}
+
+static inline bool read(const unsigned char *&Buf, const unsigned char *EndBuf,
+			int64_t &Result) {
+  return read(Buf, EndBuf, (uint64_t &)Result);
+}
+
+
+// read_vbr - Read an unsigned integer encoded in variable bitrate format.
+//
+static inline bool read_vbr(const unsigned char *&Buf, 
+			    const unsigned char *EndBuf, unsigned &Result) {
+  unsigned Shift = Result = 0;
+
+  do {
+    Result |= (unsigned)((*Buf++) & 0x7F) << Shift;
+    Shift += 7;
+  } while (Buf[-1] & 0x80 && Buf < EndBuf);
+
+  return Buf > EndBuf;
+}
+
+static inline bool read_vbr(const unsigned char *&Buf, 
+			    const unsigned char *EndBuf, uint64_t &Result) {
+  unsigned Shift = 0; Result = 0;
+
+  do {
+    Result |= (uint64_t)((*Buf++) & 0x7F) << Shift;
+    Shift += 7;
+  } while (Buf[-1] & 0x80 && Buf < EndBuf);
+  return Buf > EndBuf;
+}
+
+// read_vbr (signed) - Read a signed number stored in sign-magnitude format
+static inline bool read_vbr(const unsigned char *&Buf, 
+			    const unsigned char *EndBuf, int &Result) {
+  unsigned R;
+  if (read_vbr(Buf, EndBuf, R)) return true;
+  if (R & 1)
+    Result = -(int)(R >> 1);
+  else
+    Result =  (int)(R >> 1);
+  
+  return false;
+}
+
+
+static inline bool read_vbr(const unsigned char *&Buf, 
+			    const unsigned char *EndBuf, int64_t &Result) {
+  uint64_t R;
+  if (read_vbr(Buf, EndBuf, R)) return true;
+  if (R & 1)
+    Result = -(int64_t)(R >> 1);
+  else
+    Result =  (int64_t)(R >> 1);
+  
+  return false;
+}
+
+// align32 - Round up to multiple of 32 bits...
+static inline bool align32(const unsigned char *&Buf, 
+			   const unsigned char *EndBuf) {
+  Buf = (const unsigned char *)((unsigned long)(Buf+3) & (~3UL));
+  return Buf > EndBuf;
+}
+
+static inline bool read(const unsigned char *&Buf, const unsigned char *EndBuf, 
+			string &Result, bool Aligned = true) {
+  unsigned Size;
+  if (read_vbr(Buf, EndBuf, Size)) return true;   // Failure reading size?
+  if (Buf+Size > EndBuf) return true;             // Size invalid?
+
+  Result = string((char*)Buf, Size);
+  Buf += Size;
+
+  if (Aligned)        // If we should stay aligned do so...
+    if (align32(Buf, EndBuf)) return true;        // Failure aligning?
+
+  return false;
+}
+
+
+//===----------------------------------------------------------------------===//
+//                             Writing Primitives
+//===----------------------------------------------------------------------===//
+
+// output - If a position is specified, it must be in the valid portion of the
+// string... note that this should be inlined always so only the relevant IF 
+// body should be included...
+//
+static inline void output(unsigned i, vector<unsigned char> &Out, int pos = -1){
+#ifdef LITTLE_ENDIAN
+  if (pos == -1) 
+    Out.insert(Out.end(), (unsigned char*)&i, (unsigned char*)&i+4);
+  else
+    *(unsigned*)&Out[pos] = i;
+#else
+  if (pos == -1) { // Be endian clean, little endian is our friend
+    Out.push_back((unsigned char)i); 
+    Out.push_back((unsigned char)(i >> 8));
+    Out.push_back((unsigned char)(i >> 16));
+    Out.push_back((unsigned char)(i >> 24));
+  } else {
+    Out[pos  ] = (unsigned char)i;
+    Out[pos+1] = (unsigned char)(i >> 8);
+    Out[pos+2] = (unsigned char)(i >> 16);
+    Out[pos+3] = (unsigned char)(i >> 24);
+  }
+#endif
+}
+
+static inline void output(int i, vector<unsigned char> &Out) {
+  output((unsigned)i, Out);
+}
+
+// output_vbr - Output an unsigned value, by using the least number of bytes
+// possible.  This is useful because many of our "infinite" values are really
+// very small most of the time... but can be large a few times...
+//
+// Data format used:  If you read a byte with the night bit set, use the low 
+// seven bits as data and then read another byte...
+//
+// Note that using this may cause the output buffer to become unaligned...
+//
+static inline void output_vbr(uint64_t i, vector<unsigned char> &out) {
+  while (1) {
+    if (i < 0x80) { // done?
+      out.push_back((unsigned char)i);   // We know the high bit is clear...
+      return;
+    }
+    
+    // Nope, we are bigger than a character, output the next 7 bits and set the
+    // high bit to say that there is more coming...
+    out.push_back(0x80 | (i & 0x7F));
+    i >>= 7;  // Shift out 7 bits now...
+  }
+}
+
+static inline void output_vbr(unsigned i, vector<unsigned char> &out) {
+  while (1) {
+    if (i < 0x80) { // done?
+      out.push_back((unsigned char)i);   // We know the high bit is clear...
+      return;
+    }
+    
+    // Nope, we are bigger than a character, output the next 7 bits and set the
+    // high bit to say that there is more coming...
+    out.push_back(0x80 | (i & 0x7F));
+    i >>= 7;  // Shift out 7 bits now...
+  }
+}
+
+static inline void output_vbr(int64_t i, vector<unsigned char> &out) {
+  if (i < 0) 
+    output_vbr(((uint64_t)(-i) << 1) | 1, out); // Set low order sign bit...
+  else
+    output_vbr((uint64_t)i << 1, out);          // Low order bit is clear.
+}
+
+
+static inline void output_vbr(int i, vector<unsigned char> &out) {
+  if (i < 0) 
+    output_vbr(((unsigned)(-i) << 1) | 1, out); // Set low order sign bit...
+  else
+    output_vbr((unsigned)i << 1, out);          // Low order bit is clear.
+}
+
+// align32 - emit the minimal number of bytes that will bring us to 32 bit 
+// alignment...
+//
+static inline void align32(vector<unsigned char> &Out) {
+  int NumPads = (4-(Out.size() & 3)) & 3; // Bytes to get padding to 32 bits
+  while (NumPads--) Out.push_back((unsigned char)0xAB);
+}
+
+static inline void output(const string &s, vector<unsigned char> &Out, 
+			  bool Aligned = true) {
+  unsigned Len = s.length();
+  output_vbr(Len, Out);             // Strings may have an arbitrary length...
+  Out.insert(Out.end(), s.begin(), s.end());
+
+  if (Aligned)
+    align32(Out);                   // Make sure we are now aligned...
+}
+
+#endif