+ /// emitAlignment - Move the CurBufferPtr pointer up to the specified
+ /// alignment (saturated to BufferEnd of course).
+ void emitAlignment(unsigned Alignment) {
+ if (Alignment == 0) Alignment = 1;
+
+ if(Alignment <= (uintptr_t)(BufferEnd-CurBufferPtr)) {
+ // Move the current buffer ptr up to the specified alignment.
+ CurBufferPtr =
+ (uint8_t*)(((uintptr_t)CurBufferPtr+Alignment-1) &
+ ~(uintptr_t)(Alignment-1));
+ } else {
+ CurBufferPtr = BufferEnd;
+ }
+ }
+
+
+ /// emitULEB128Bytes - This callback is invoked when a ULEB128 needs to be
+ /// written to the output stream.
+ void emitULEB128Bytes(uint64_t Value) {
+ do {
+ uint8_t Byte = Value & 0x7f;
+ Value >>= 7;
+ if (Value) Byte |= 0x80;
+ emitByte(Byte);
+ } while (Value);
+ }
+
+ /// emitSLEB128Bytes - This callback is invoked when a SLEB128 needs to be
+ /// written to the output stream.
+ void emitSLEB128Bytes(uint64_t Value) {
+ uint64_t Sign = Value >> (8 * sizeof(Value) - 1);
+ bool IsMore;
+
+ do {
+ uint8_t Byte = Value & 0x7f;
+ Value >>= 7;
+ IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
+ if (IsMore) Byte |= 0x80;
+ emitByte(Byte);
+ } while (IsMore);
+ }
+
+ /// emitString - This callback is invoked when a String needs to be
+ /// written to the output stream.
+ void emitString(const std::string &String) {
+ for (unsigned i = 0, N = static_cast<unsigned>(String.size());
+ i < N; ++i) {
+ uint8_t C = String[i];
+ emitByte(C);
+ }
+ emitByte(0);
+ }
+
+ /// emitInt32 - Emit a int32 directive.
+ void emitInt32(int32_t Value) {
+ if (4 <= BufferEnd-CurBufferPtr) {
+ *((uint32_t*)CurBufferPtr) = Value;
+ CurBufferPtr += 4;
+ } else {
+ CurBufferPtr = BufferEnd;
+ }
+ }
+
+ /// emitInt64 - Emit a int64 directive.
+ void emitInt64(uint64_t Value) {
+ if (8 <= BufferEnd-CurBufferPtr) {
+ *((uint64_t*)CurBufferPtr) = Value;
+ CurBufferPtr += 8;
+ } else {
+ CurBufferPtr = BufferEnd;
+ }
+ }
+
+ /// emitInt32At - Emit the Int32 Value in Addr.
+ void emitInt32At(uintptr_t *Addr, uintptr_t Value) {
+ if (Addr >= (uintptr_t*)BufferBegin && Addr < (uintptr_t*)BufferEnd)
+ (*(uint32_t*)Addr) = (uint32_t)Value;
+ }
+
+ /// emitInt64At - Emit the Int64 Value in Addr.
+ void emitInt64At(uintptr_t *Addr, uintptr_t Value) {
+ if (Addr >= (uintptr_t*)BufferBegin && Addr < (uintptr_t*)BufferEnd)
+ (*(uint64_t*)Addr) = (uint64_t)Value;
+ }
+
+ /// processDebugLoc - Records debug location information about a
+ /// MachineInstruction. This is called before emitting any bytes associated
+ /// with the instruction. Even if successive instructions have the same debug
+ /// location, this method will be called for each one.
+ virtual void processDebugLoc(DebugLoc DL, bool BeforePrintintInsn) {}
+
+ /// emitLabel - Emits a label
+ virtual void emitLabel(MCSymbol *Label) = 0;
+
+ /// allocateSpace - Allocate a block of space in the current output buffer,
+ /// returning null (and setting conditions to indicate buffer overflow) on
+ /// failure. Alignment is the alignment in bytes of the buffer desired.
+ virtual void *allocateSpace(uintptr_t Size, unsigned Alignment) {
+ emitAlignment(Alignment);
+ void *Result;
+
+ // Check for buffer overflow.
+ if (Size >= (uintptr_t)(BufferEnd-CurBufferPtr)) {
+ CurBufferPtr = BufferEnd;
+ Result = 0;
+ } else {
+ // Allocate the space.
+ Result = CurBufferPtr;
+ CurBufferPtr += Size;
+ }
+
+ return Result;
+ }
+
+ /// StartMachineBasicBlock - This should be called by the target when a new
+ /// basic block is about to be emitted. This way the MCE knows where the
+ /// start of the block is, and can implement getMachineBasicBlockAddress.
+ virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) = 0;
+
+ /// getCurrentPCValue - This returns the address that the next emitted byte
+ /// will be output to.