Initial import.

T0/BlobWriter.cs

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.IO;
+using System.Text;
+
+/*
+ * A simple class for writing out bytes as hexadecimal constants or
+ * explicit expressions for the initializer of a C array of 'unsigned
+ * char'. It starts every line with a given number of tabs, and aims at
+ * keeping lines below a given threshold (each indentation tab counts as
+ * 8 characters). An explicit newline is inserted before the first
+ * element, and commas are used as separators.
+ */
+
+class BlobWriter {
+
+	TextWriter w;
+	int maxLineLen;
+	int indent;
+	int lineLen;
+
+	/*
+	 * Create a new instance. 'maxLineLen' is in characters, and
+	 * 'indent' is the number of tab characters at the start of
+	 * each line.
+	 */
+	internal BlobWriter(TextWriter w, int maxLineLen, int indent)
+	{
+		this.w = w;
+		this.maxLineLen = maxLineLen;
+		this.indent = indent;
+		lineLen = -1;
+	}
+
+	void DoNL()
+	{
+		w.WriteLine();
+		for (int i = 0; i < indent; i ++) {
+			w.Write('\t');
+		}
+		lineLen = (indent << 3);
+	}
+
+	/*
+	 * Append a new byte value; it will be converted to an hexadecimal
+	 * constant in the output.
+	 */
+	internal void Append(byte b)
+	{
+		if (lineLen < 0) {
+			DoNL();
+		} else {
+			w.Write(',');
+			lineLen ++;
+			if ((lineLen + 5) > maxLineLen) {
+				DoNL();
+			} else {
+				w.Write(' ');
+				lineLen ++;
+			}
+		}
+		w.Write("0x{0:X2}", b);
+		lineLen += 4;
+	}
+
+	/*
+	 * Append a C expression, which will be used as is. The expression
+	 * may resolve to several bytes if it uses internal commas. The
+	 * writer will try to honour the expected line length, but it
+	 * won't insert a newline character inside the expression.
+	 */
+	internal void Append(string expr)
+	{
+		if (lineLen < 0) {
+			DoNL();
+		} else {
+			w.Write(',');
+			lineLen ++;
+			if ((lineLen + 1 + expr.Length) > maxLineLen) {
+				DoNL();
+			} else {
+				w.Write(' ');
+				lineLen ++;
+			}
+		}
+		w.Write("{0}", expr);
+		lineLen += expr.Length;
+	}
+}

T0/CPU.cs

@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * Execution of code during compilation is done in a virtual CPU
+ * incarnated by this class, that contains the relevant registers.
+ *
+ * Accesses to the data on the stack are mapped to accesses to an
+ * internal array, with no explicit control on boundaries. Since the
+ * internal array may be larger than the actual stack contents,
+ * nonsensical accesses may still "work" to some extent. The whole
+ * thing won't derail beyond the CLR VM, though.
+ */
+
+class CPU {
+
+	/*
+	 * Next instruction to execute is in ipBuf[ipOff].
+	 */
+	internal Opcode[] ipBuf;
+	internal int ipOff;
+
+	/*
+	 * stackBuf and stackPtr implement the data stack. The system
+	 * stack uses frames; 'rsp' points to the current top frame.
+	 */
+	TValue[] stackBuf;
+	int stackPtr;
+	Frame rsp;
+
+	internal CPU()
+	{
+		stackBuf = new TValue[16];
+		stackPtr = -1;
+		rsp = null;
+	}
+
+	/*
+	 * Enter a function, reserving space for 'numLocals' local variables.
+	 */
+	internal void Enter(Opcode[] code, int numLocals)
+	{
+		Frame f = new Frame(rsp, numLocals);
+		rsp = f;
+		f.savedIpBuf = ipBuf;
+		f.savedIpOff = ipOff;
+		ipBuf = code;
+		ipOff = 0;
+	}
+
+	/*
+	 * Exit the current function.
+	 */
+	internal void Exit()
+	{
+		ipBuf = rsp.savedIpBuf;
+		ipOff = rsp.savedIpOff;
+		rsp = rsp.upper;
+	}
+
+	/*
+	 * Get the current stack depth (number of elements).
+	 */
+	internal int Depth {
+		get {
+			return stackPtr + 1;
+		}
+	}
+
+	/*
+	 * Pop a value from the stack.
+	 */
+	internal TValue Pop()
+	{
+		return stackBuf[stackPtr --];
+	}
+
+	/*
+	 * Push a value on the stack.
+	 */
+	internal void Push(TValue v)
+	{
+		int len = stackBuf.Length;
+		if (++ stackPtr == len) {
+			TValue[] nbuf = new TValue[len << 1];
+			Array.Copy(stackBuf, 0, nbuf, 0, len);
+			stackBuf = nbuf;
+		}
+		stackBuf[stackPtr] = v;
+	}
+
+	/*
+	 * Look at the value at depth 'depth' (0 is top of stack). The
+	 * stack is unchanged.
+	 */
+	internal TValue Peek(int depth)
+	{
+		return stackBuf[stackPtr - depth];
+	}
+
+	/*
+	 * Rotate the stack at depth 'depth': the value at that depth
+	 * is moved to the top of stack.
+	 */
+	internal void Rot(int depth)
+	{
+		TValue v = stackBuf[stackPtr - depth];
+		Array.Copy(stackBuf, stackPtr - (depth - 1),
+			stackBuf, stackPtr - depth, depth);
+		stackBuf[stackPtr] = v;
+	}
+
+	/*
+	 * Inverse-rotate the stack at depth 'depth': the value at the
+	 * top of stack is moved to that depth.
+	 */
+	internal void NRot(int depth)
+	{
+		TValue v = stackBuf[stackPtr];
+		Array.Copy(stackBuf, stackPtr - depth,
+			stackBuf, stackPtr - (depth - 1), depth);
+		stackBuf[stackPtr - depth] = v;
+	}
+
+	/*
+	 * Get the current contents of the local variable 'num'.
+	 */
+	internal TValue GetLocal(int num)
+	{
+		return rsp.locals[num];
+	}
+
+	/*
+	 * Set the contents of the local variable 'num'.
+	 */
+	internal void PutLocal(int num, TValue v)
+	{
+		rsp.locals[num] = v;
+	}
+
+	/*
+	 * The system stack really is a linked list of Frame instances.
+	 */
+	class Frame {
+
+		internal Frame upper;
+		internal Opcode[] savedIpBuf;
+		internal int savedIpOff;
+		internal TValue[] locals;
+
+		internal Frame(Frame upper, int numLocals)
+		{
+			this.upper = upper;
+			locals = new TValue[numLocals];
+		}
+	}
+}

T0/CodeElement.cs

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+abstract class CodeElement {
+
+	internal int Address { get; set; }
+
+	internal int LastLength { get; set; }
+
+	internal abstract int Length { get; }
+
+	internal CodeElement()
+	{
+		Address = -1;
+	}
+
+	internal virtual void SetJumpTarget(CodeElement target)
+	{
+		throw new Exception("Code element accepts no target");
+	}
+
+	internal abstract int Encode(BlobWriter bw);
+
+	internal static int Encode7EUnsigned(uint val, BlobWriter bw)
+	{
+		int len = 1;
+		for (uint w = val; w >= 0x80; w >>= 7) {
+			len ++;
+		}
+		if (bw != null) {
+			for (int k = (len - 1) * 7; k >= 0; k -= 7) {
+				int x = (int)(val >> k) & 0x7F;
+				if (k > 0) {
+					x |= 0x80;
+				}
+				bw.Append((byte)x);
+			}
+		}
+		return len;
+	}
+
+	internal static int Encode7ESigned(int val, BlobWriter bw)
+	{
+		int len = 1;
+		if (val < 0) {
+			for (int w = val; w < -0x40; w >>= 7) {
+				len ++;
+			}
+		} else {
+			for (int w = val; w >= 0x40; w >>= 7) {
+				len ++;
+			}
+		}
+		if (bw != null) {
+			for (int k = (len - 1) * 7; k >= 0; k -= 7) {
+				int x = (int)(val >> k) & 0x7F;
+				if (k > 0) {
+					x |= 0x80;
+				}
+				bw.Append((byte)x);
+			}
+		}
+		return len;
+	}
+}

T0/CodeElementJump.cs

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class CodeElementJump : CodeElement {
+
+	uint jumpType;
+	CodeElement target;
+
+	internal CodeElementJump(uint jumpType)
+	{
+		this.jumpType = jumpType;
+	}
+
+	internal override int Length {
+		get {
+			int len = Encode7EUnsigned(jumpType, null);
+			int joff = JumpOff;
+			if (joff == Int32.MinValue) {
+				len ++;
+			} else {
+				len += Encode7ESigned(joff, null);
+			}
+			return len;
+		}
+	}
+
+	internal override void SetJumpTarget(CodeElement target)
+	{
+		this.target = target;
+	}
+
+	int JumpOff {
+		get {
+			if (target == null || Address < 0 || target.Address < 0)
+			{
+				return Int32.MinValue;
+			} else {
+				return target.Address - (Address + LastLength);
+			}
+		}
+	}
+
+	internal override int Encode(BlobWriter bw)
+	{
+		if (bw == null) {
+			return Length;
+		}
+		int len = Encode7EUnsigned(jumpType, bw);
+		int joff = JumpOff;
+		if (joff == Int32.MinValue) {
+			throw new Exception("Unresolved addresses");
+		}
+		return len + Encode7ESigned(joff, bw);
+	}
+}

T0/CodeElementUInt.cs

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class CodeElementUInt : CodeElement {
+
+	uint val;
+
+	internal CodeElementUInt(uint val) : base()
+	{
+		this.val = val;
+	}
+
+	internal override int Length {
+		get {
+			return Encode7EUnsigned(val, null);
+		}
+	}
+
+	internal override int Encode(BlobWriter bw)
+	{
+		return Encode7EUnsigned(val, bw);
+	}
+}

T0/CodeElementUIntExpr.cs

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class CodeElementUIntExpr : CodeElement {
+
+	uint val;
+	TPointerExpr cx;
+	int off;
+
+	internal CodeElementUIntExpr(uint val,
+		TPointerExpr cx, int off) : base()
+	{
+		this.val = val;
+		this.cx = cx;
+		this.off = off;
+	}
+
+	internal override int Length {
+		get {
+			return Encode7EUnsigned(val, null)
+				+ (cx.GetMaxBitLength(off) + 6) / 7;
+		}
+	}
+
+	internal override int Encode(BlobWriter bw)
+	{
+		int len1 = Encode7EUnsigned(val, bw);
+		int len2 = (cx.GetMaxBitLength(off) + 6) / 7;
+		bw.Append(String.Format("T0_INT{0}({1})",
+			len2, cx.ToCExpr(off)));
+		return len1 + len2;
+	}
+}

T0/CodeElementUIntInt.cs

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class CodeElementUIntInt : CodeElement {
+
+	uint val1;
+	int val2;
+
+	internal CodeElementUIntInt(uint val1, int val2) : base()
+	{
+		this.val1 = val1;
+		this.val2 = val2;
+	}
+
+	internal override int Length {
+		get {
+			return Encode7EUnsigned(val1, null)
+				+ Encode7ESigned(val2, null);
+		}
+	}
+
+	internal override int Encode(BlobWriter bw)
+	{
+		int len = Encode7EUnsigned(val1, bw);
+		len += Encode7ESigned(val2, bw);
+		return len;
+	}
+}

T0/CodeElementUIntUInt.cs

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class CodeElementUIntUInt : CodeElement {
+
+	uint val1, val2;
+
+	internal CodeElementUIntUInt(uint val1, uint val2) : base()
+	{
+		this.val1 = val1;
+		this.val2 = val2;
+	}
+
+	internal override int Length {
+		get {
+			return Encode7EUnsigned(val1, null)
+				+ Encode7EUnsigned(val2, null);
+		}
+	}
+
+	internal override int Encode(BlobWriter bw)
+	{
+		int len = Encode7EUnsigned(val1, bw);
+		len += Encode7EUnsigned(val2, bw);
+		return len;
+	}
+}

T0/ConstData.cs

@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+class ConstData {
+
+	internal long ID { get; private set; }
+	internal int Address { get; set; }
+	internal int Length {
+		get {
+			return len;
+		}
+	}
+
+	byte[] buf;
+	int len;
+
+	internal ConstData(T0Comp ctx)
+	{
+		ID = ctx.NextBlobID();
+		buf = new byte[4];
+		len = 0;
+	}
+
+	void Expand(int elen)
+	{
+		int tlen = len + elen;
+		if (tlen > buf.Length) {
+			int nlen = Math.Max(buf.Length << 1, tlen);
+			byte[] nbuf = new byte[nlen];
+			Array.Copy(buf, 0, nbuf, 0, len);
+			buf = nbuf;
+		}
+	}
+
+	internal void Add8(byte b)
+	{
+		Expand(1);
+		buf[len ++] = b;
+	}
+
+	internal void Add16(int x)
+	{
+		Expand(2);
+		buf[len ++] = (byte)(x >> 8);
+		buf[len ++] = (byte)x;
+	}
+
+	internal void Add24(int x)
+	{
+		Expand(3);
+		buf[len ++] = (byte)(x >> 16);
+		buf[len ++] = (byte)(x >> 8);
+		buf[len ++] = (byte)x;
+	}
+
+	internal void Add32(int x)
+	{
+		Expand(4);
+		buf[len ++] = (byte)(x >> 24);
+		buf[len ++] = (byte)(x >> 16);
+		buf[len ++] = (byte)(x >> 8);
+		buf[len ++] = (byte)x;
+	}
+
+	internal void AddString(string s)
+	{
+		byte[] sd = Encoding.UTF8.GetBytes(s);
+		Expand(sd.Length + 1);
+		Array.Copy(sd, 0, buf, len, sd.Length);
+		buf[len + sd.Length] = 0;
+		len += sd.Length + 1;
+	}
+
+	void CheckIndex(int off, int dlen)
+	{
+		if (off < 0 || off > (len - dlen)) {
+			throw new IndexOutOfRangeException();
+		}
+	}
+
+	internal void Set8(int off, byte v)
+	{
+		CheckIndex(off, 1);
+		buf[off] = v;
+	}
+
+	internal byte Read8(int off)
+	{
+		CheckIndex(off, 1);
+		return buf[off];
+	}
+
+	internal int Read16(int off)
+	{
+		CheckIndex(off, 2);
+		return (buf[off] << 8) | buf[off + 1];
+	}
+
+	internal int Read24(int off)
+	{
+		CheckIndex(off, 3);
+		return (buf[off] << 16) | (buf[off + 1] << 8) | buf[off + 2];
+	}
+
+	internal int Read32(int off)
+	{
+		CheckIndex(off, 4);
+		return (buf[off] << 24) | (buf[off + 1] << 16)
+			| (buf[off + 2] << 8) | buf[off + 3];
+	}
+
+	internal string ToString(int off)
+	{
+		StringBuilder sb = new StringBuilder();
+		for (;;) {
+			int x = DecodeUTF8(ref off);
+			if (x == 0) {
+				return sb.ToString();
+			}
+			if (x < 0x10000) {
+				sb.Append((char)x);
+			} else {
+				x -= 0x10000;
+				sb.Append((char)(0xD800 + (x >> 10)));
+				sb.Append((char)(0xDC00 + (x & 0x3FF)));
+			}
+		}
+	}
+
+	int DecodeUTF8(ref int off)
+	{
+		if (off >= len) {
+			throw new IndexOutOfRangeException();
+		}
+		int x = buf[off ++];
+		if (x < 0xC0 || x > 0xF7) {
+			return x;
+		}
+		int elen, acc;
+		if (x >= 0xF0) {
+			elen = 3;
+			acc = x & 0x07;
+		} else if (x >= 0xE0) {
+			elen = 2;
+			acc = x & 0x0F;
+		} else {
+			elen = 1;
+			acc = x & 0x1F;
+		}
+		if (off + elen > len) {
+			return x;
+		}
+		for (int i = 0; i < elen; i ++) {
+			int y = buf[off + i];
+			if (y < 0x80 || y >= 0xC0) {
+				return x;
+			}
+			acc = (acc << 6) + (y & 0x3F);
+		}
+		if (acc > 0x10FFFF) {
+			return x;
+		}
+		off += elen;
+		return acc;
+	}
+
+	internal void Encode(BlobWriter bw)
+	{
+		for (int i = 0; i < len; i ++) {
+			bw.Append(buf[i]);
+		}
+	}
+}

T0/Opcode.cs

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+abstract class Opcode {
+
+	internal Opcode()
+	{
+	}
+
+	/*
+	 * Execute this opcode.
+	 */
+	internal abstract void Run(CPU cpu);
+
+	/*
+	 * Resolve the target (word reference) for this opcode.
+	 */
+	internal virtual void ResolveTarget(Word target)
+	{
+		throw new Exception("Not a call opcode");
+	}
+
+	/*
+	 * Resolve the jump offset for this opcode. Displacement is
+	 * relative to the address of the opcode that immediately follows
+	 * the jump code; thus, 0 implies no jump at all.
+	 */
+	internal virtual void ResolveJump(int disp)
+	{
+		throw new Exception("Not a jump opcode");
+	}
+
+	/*
+	 * Get the Word that this opcode references; this can happen
+	 * only with "call" and "const" opcodes. For all other opcodes,
+	 * this method returns null.
+	 */
+	internal virtual Word GetReference(T0Comp ctx)
+	{
+		return null;
+	}
+
+	/*
+	 * Get the data block that this opcode references; this can happen
+	 * only with "const" opcodes. For all other opcodes, this method
+	 * returns null.
+	 */
+	internal virtual ConstData GetDataBlock(T0Comp ctx)
+	{
+		return null;
+	}
+
+	/*
+	 * Test whether this opcode may "fall through", i.e. execution
+	 * may at least potentially proceed to the next opcode.
+	 */
+	internal virtual bool MayFallThrough {
+		get {
+			return true;
+		}
+	}
+
+	/*
+	 * Get jump displacement. For non-jump opcodes, this returns 0.
+	 */
+	internal virtual int JumpDisp {
+		get {
+			return 0;
+		}
+	}
+
+	/*
+	 * Get stack effect for this opcode (number of elements added to
+	 * the stack, could be negative). For OpcodeCall, this returns
+	 * 0.
+	 */
+	internal virtual int StackAction {
+		get {
+			return 0;
+		}
+	}
+
+	internal abstract CodeElement ToCodeElement();
+
+	/*
+	 * This method is called for the CodeElement corresponding to
+	 * this opcode, at gcode[off]; it is used to compute actual
+	 * byte jump offsets when converting code to C.
+	 */
+	internal virtual void FixUp(CodeElement[] gcode, int off)
+	{
+	}
+}

T0/OpcodeCall.cs

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeCall : Opcode {
+
+	Word target;
+
+	internal OpcodeCall() : this(null)
+	{
+	}
+
+	internal OpcodeCall(Word target)
+	{
+		this.target = target;
+	}
+
+	internal override void ResolveTarget(Word target)
+	{
+		if (this.target != null) {
+			throw new Exception("Opcode already resolved");
+		}
+		this.target = target;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		target.Run(cpu);
+	}
+
+	internal override Word GetReference(T0Comp ctx)
+	{
+		if (target == null) {
+			throw new Exception("Unresolved call target");
+		}
+		return target;
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementUInt((uint)target.Slot);
+	}
+
+	public override string ToString()
+	{
+		return "call " + (target == null ? "UNRESOLVED" : target.Name);
+	}
+}

T0/OpcodeConst.cs

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeConst : Opcode {
+
+	TValue val;
+
+	internal OpcodeConst(TValue val)
+	{
+		this.val = val;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		cpu.Push(val);
+	}
+
+	internal override Word GetReference(T0Comp ctx)
+	{
+		TPointerXT xt = val.ptr as TPointerXT;
+		if (xt == null) {
+			return null;
+		}
+		xt.Resolve(ctx);
+		return xt.Target;
+	}
+
+	internal override ConstData GetDataBlock(T0Comp ctx)
+	{
+		TPointerBlob bp = val.ptr as TPointerBlob;
+		return bp == null ? null : bp.Blob;
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		if (val.ptr == null) {
+			return new CodeElementUIntInt(1, val.Int);
+		}
+		TPointerXT xt = val.ptr as TPointerXT;
+		if (xt != null) {
+			if (val.x != 0) {
+				throw new Exception(
+					"Cannot compile XT: non-zero offset");
+			}
+			return new CodeElementUIntInt(1, xt.Target.Slot);
+		}
+		TPointerBlob bp = val.ptr as TPointerBlob;
+		if (bp != null) {
+			return new CodeElementUIntInt(1,
+				val.x + bp.Blob.Address);
+		}
+		TPointerExpr cx = val.ptr as TPointerExpr;
+		if (cx != null) {
+			return new CodeElementUIntExpr(1, cx, val.x);
+		}
+		throw new Exception(String.Format(
+			"Cannot embed constant (type = {0})",
+			val.ptr.GetType().FullName));
+	}
+
+	internal override int StackAction {
+		get {
+			return 1;
+		}
+	}
+
+	public override string ToString()
+	{
+		return "const " + val.ToString();
+	}
+}

T0/OpcodeGetLocal.cs

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeGetLocal : Opcode {
+
+	int num;
+
+	internal OpcodeGetLocal(int num)
+	{
+		this.num = num;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		cpu.Push(cpu.GetLocal(num));
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementUIntUInt(2, (uint)num);
+	}
+
+	internal override int StackAction {
+		get {
+			return 1;
+		}
+	}
+
+	public override string ToString()
+	{
+		return "getlocal " + num;
+	}
+}

T0/OpcodeJump.cs

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+abstract class OpcodeJump : Opcode {
+
+	int disp;
+
+	internal OpcodeJump() : this(Int32.MinValue)
+	{
+	}
+
+	internal OpcodeJump(int disp)
+	{
+		this.disp = disp;
+	}
+
+	internal override int JumpDisp {
+		get {
+			return disp;
+		}
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		cpu.ipOff += disp;
+	}
+
+	internal override void ResolveJump(int disp)
+	{
+		if (this.disp != Int32.MinValue) {
+			throw new Exception("Jump already resolved");
+		}
+		this.disp = disp;
+	}
+
+	internal override void FixUp(CodeElement[] gcode, int off)
+	{
+		gcode[off].SetJumpTarget(gcode[off + 1 + disp]);
+	}
+}

T0/OpcodeJumpIf.cs

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeJumpIf : OpcodeJump {
+
+	internal OpcodeJumpIf() : base()
+	{
+	}
+
+	internal OpcodeJumpIf(int disp) : base(disp)
+	{
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		TValue v = cpu.Pop();
+		if (v.Bool) {
+			base.Run(cpu);
+		}
+	}
+
+	internal override int StackAction {
+		get {
+			return -1;
+		}
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementJump(5);
+	}
+
+	public override string ToString()
+	{
+		if (JumpDisp == Int32.MinValue) {
+			return "jumpif UNRESOLVED";
+		} else {
+			return "jumpif disp=" + JumpDisp;
+		}
+	}
+}

T0/OpcodeJumpIfNot.cs

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeJumpIfNot : OpcodeJump {
+
+	internal OpcodeJumpIfNot() : base()
+	{
+	}
+
+	internal OpcodeJumpIfNot(int disp) : base(disp)
+	{
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		TValue v = cpu.Pop();
+		if (!v.Bool) {
+			base.Run(cpu);
+		}
+	}
+
+	internal override int StackAction {
+		get {
+			return -1;
+		}
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementJump(6);
+	}
+
+	public override string ToString()
+	{
+		if (JumpDisp == Int32.MinValue) {
+			return "jumpifnot UNRESOLVED";
+		} else {
+			return "jumpifnot disp=" + JumpDisp;
+		}
+	}
+}

T0/OpcodeJumpUncond.cs

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeJumpUncond : OpcodeJump {
+
+	internal OpcodeJumpUncond() : base()
+	{
+	}
+
+	internal OpcodeJumpUncond(int disp) : base(disp)
+	{
+	}
+
+	/*
+	 * Unconditional jumps do not "fall through" unless they
+	 * happen to be a jump to the next instruction...
+	 */
+	internal override bool MayFallThrough {
+		get {
+			return JumpDisp == 0;
+		}
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementJump(4);
+	}
+
+	public override string ToString()
+	{
+		if (JumpDisp == Int32.MinValue) {
+			return "jump UNRESOLVED";
+		} else {
+			return "jump disp=" + JumpDisp;
+		}
+	}
+}

T0/OpcodePutLocal.cs

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodePutLocal : Opcode {
+
+	int num;
+
+	internal OpcodePutLocal(int num)
+	{
+		this.num = num;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		cpu.PutLocal(num, cpu.Pop());
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementUIntUInt(3, (uint)num);
+	}
+
+	internal override int StackAction {
+		get {
+			return -1;
+		}
+	}
+
+	public override string ToString()
+	{
+		return "putlocal " + num;
+	}
+}

T0/OpcodeRet.cs

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class OpcodeRet : Opcode {
+
+	internal override void Run(CPU cpu)
+	{
+		cpu.Exit();
+	}
+
+	internal override bool MayFallThrough {
+		get {
+			return false;
+		}
+	}
+
+	internal override CodeElement ToCodeElement()
+	{
+		return new CodeElementUInt(0);
+	}
+
+	public override string ToString()
+	{
+		return "ret";
+	}
+}

T0/SType.cs

@@ -0,0 +1,129 @@
+using System;
+
+/*
+ * This structure contains the stack effect of a word: number of stack
+ * element consumed on input, and number of stack element produced on
+ * output.
+ */
+
+struct SType {
+
+	/*
+	 * Get number of stack elements consumed on input; this is -1 if
+	 * the stack effect is not known.
+	 */
+	internal int DataIn {
+		get {
+			return din;
+		}
+	}
+
+	/*
+	 * Get number of stack elements produced on output; this is -1 if
+	 * either the stack effect is not known, or if the word never
+	 * exits.
+	 */
+	internal int DataOut {
+		get {
+			return dout;
+		}
+	}
+
+	/*
+	 * Tell whether the stack effect is known.
+	 */
+	internal bool IsKnown {
+		get {
+			return din >= 0;
+		}
+	}
+
+	/*
+	 * Tell whether the stack effect is known and the word never exits.
+	 */
+	internal bool NoExit {
+		get {
+			return din >= 0 && dout < 0;
+		}
+	}
+
+	int din, dout;
+
+	internal SType(int din, int dout)
+	{
+		if (din < 0) {
+			din = -1;
+		}
+		if (dout < 0) {
+			dout = -1;
+		}
+		this.din = din;
+		this.dout = dout;
+	}
+
+	/*
+	 * Special value for the unknown stack effect.
+	 */
+	internal static SType UNKNOWN = new SType(-1, -1);
+
+	/*
+	 * Constant for the "blank stack effect".
+	 */
+	internal static SType BLANK = new SType(0, 0);
+
+	public static bool operator ==(SType s1, SType s2)
+	{
+		return s1.din == s2.din && s1.dout == s2.dout;
+	}
+
+	public static bool operator !=(SType s1, SType s2)
+	{
+		return s1.din != s2.din || s1.dout != s2.dout;
+	}
+
+	public override bool Equals(Object obj)
+	{
+		return (obj is SType) && ((SType)obj == this);
+	}
+
+	public override int GetHashCode()
+	{
+		return din * 31 + dout * 17;
+	}
+
+	public override string ToString()
+	{
+		if (!IsKnown) {
+			return "UNKNOWN";
+		} else if (NoExit) {
+			return string.Format("in:{0},noexit", din);
+		} else {
+			return string.Format("in:{0},out:{1}", din, dout);
+		}
+	}
+
+	/*
+	 * Test whether this stack effect is a sub-effect of the provided
+	 * stack effect s. Stack effect s1 is a sub-effect of stack-effect
+	 * s2 if any of the following holds:
+	 * -- s1 and s2 are known, s1.din <= s2.din and s1 does not exit.
+	 * -- s1 and s2 are known, s1.din <= s2.din, s1 and s2 exit,
+	 *    and s1.din - s1.dout == s2.din - s2.dout.
+	 */
+	internal bool IsSubOf(SType s)
+	{
+		if (!IsKnown || !s.IsKnown) {
+			return false;
+		}
+		if (din > s.din) {
+			return false;
+		}
+		if (NoExit) {
+			return true;
+		}
+		if (s.NoExit) {
+			return false;
+		}
+		return (din - dout) == (s.din - s.dout);
+	}
+}

T0/TPointerBase.cs

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class TPointerBase {
+
+	/* obsolete
+	internal virtual TValue Get(TValue vp)
+	{
+		throw new Exception(
+			"cannot get values from this pointer");
+	}
+
+	internal virtual void Set(TValue vp, TValue nval)
+	{
+		throw new Exception(
+			"cannot set values to this pointer");
+	}
+	*/
+
+	internal virtual bool ToBool(TValue vp)
+	{
+		return true;
+	}
+
+	internal virtual void Execute(T0Comp ctx, CPU cpu)
+	{
+		throw new Exception("value is not an xt: " + ToString());
+	}
+
+	internal virtual string ToString(TValue vp)
+	{
+		return String.Format("{0}+{1}",
+			GetType().Name, vp.x);
+	}
+
+	internal virtual bool Equals(TPointerBase tp)
+	{
+		return this == tp;
+	}
+}

T0/TPointerBlob.cs

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class TPointerBlob : TPointerBase {
+
+	internal ConstData Blob { get; private set; }
+
+	internal TPointerBlob(ConstData cd)
+	{
+		this.Blob = cd;
+	}
+
+	internal TPointerBlob(T0Comp owner, string s)
+	{
+		Blob = new ConstData(owner);
+		Blob.AddString(s);
+	}
+
+	/* obsolete
+	internal override TValue Get8(TValue vp)
+	{
+		return new TValue((int)Blob.Read8(vp.x));
+	}
+
+	internal override TValue Get16(TValue vp)
+	{
+		return new TValue((int)Blob.Read16(vp.x));
+	}
+
+	internal override TValue Get24(TValue vp)
+	{
+		return new TValue((int)Blob.Read24(vp.x));
+	}
+
+	internal override TValue Get32(TValue vp)
+	{
+		return new TValue((int)Blob.Read32(vp.x));
+	}
+	*/
+
+	internal override string ToString(TValue vp)
+	{
+		return Blob.ToString(vp.x);
+	}
+
+	internal override bool Equals(TPointerBase tp)
+	{
+		TPointerBlob tb = tp as TPointerBlob;
+		return tb != null && Blob == tb.Blob;
+	}
+}

T0/TPointerExpr.cs

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+
+class TPointerExpr : TPointerBase {
+
+	string expr;
+	int min, max;
+
+	internal TPointerExpr(string expr, int min, int max)
+	{
+		this.expr = expr;
+		this.min = min;
+		this.max = max;
+	}
+
+	internal override bool ToBool(TValue vp)
+	{
+		throw new Exception("Cannot evaluate C-expr at compile time");
+	}
+
+	internal override string ToString(TValue vp)
+	{
+		return ToCExpr(vp.x);
+	}
+
+	internal string ToCExpr(int off)
+	{
+		if (off == 0) {
+			return expr;
+		} else if (off > 0) {
+			return String.Format(
+				"(uint32_t)({0}) + {1}", expr, off);
+		} else {
+			return String.Format(
+				"(uint32_t)({0}) - {1}", expr, -(long)off);
+		}
+	}
+
+	internal int GetMaxBitLength(int off)
+	{
+		long rmin = (long)min + off;
+		long rmax = (long)max + off;
+		int numBits = 1;
+		if (rmin < 0) {
+			numBits = Math.Max(numBits, BitLength(rmin));
+		}
+		if (rmax > 0) {
+			numBits = Math.Max(numBits, BitLength(rmax));
+		}
+		return Math.Min(numBits, 32);
+	}
+
+	/*
+	 * Get the minimal bit length of a value. This is for a signed
+	 * representation: the length includes a sign bit. Thus, the
+	 * returned value will be at least 1.
+	 */
+	static int BitLength(long v)
+	{
+		int num = 1;
+		if (v < 0) {
+			while (v != -1) {
+				num ++;
+				v >>= 1;
+			}
+		} else {
+			while (v != 0) {
+				num ++;
+				v >>= 1;
+			}
+		}
+		return num;
+	}
+}

T0/TPointerNull.cs

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class TPointerNull : TPointerBase {
+
+	internal override bool ToBool(TValue vp)
+	{
+		return false;
+	}
+
+	internal override string ToString(TValue vp)
+	{
+		return "null";
+	}
+
+	internal override bool Equals(TPointerBase tp)
+	{
+		return tp is TPointerNull;
+	}
+}

T0/TPointerXT.cs

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class TPointerXT : TPointerBase {
+
+	internal string Name {
+		get; private set;
+	}
+
+	internal Word Target {
+		get; private set;
+	}
+
+	internal TPointerXT(string name)
+	{
+		this.Name = name;
+		this.Target = null;
+	}
+
+	internal TPointerXT(Word target)
+	{
+		this.Name = target.Name;
+		this.Target = target;
+	}
+
+	internal void Resolve(T0Comp ctx)
+	{
+		if (Target == null) {
+			Target = ctx.Lookup(Name);
+		}
+	}
+
+	internal override void Execute(T0Comp ctx, CPU cpu)
+	{
+		Resolve(ctx);
+		Target.Run(cpu);
+	}
+
+	internal override string ToString(TValue vp)
+	{
+		return String.Format("<'{0}>", Name);
+	}
+
+	internal override bool Equals(TPointerBase tp)
+	{
+		TPointerXT tx = tp as TPointerXT;
+		return tx != null && Name == tx.Name;
+	}
+}

T0/TValue.cs

@@ -0,0 +1,231 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * Each value is represented with a TValue structure. Integers use the 'x'
+ * field, and 'ptr' is null; for pointers, the 'ptr' field is used, and the
+ * 'x' is then an offset in the object represented by 'ptr'.
+ */
+
+struct TValue {
+
+	internal int x;
+	internal TPointerBase ptr;
+
+	internal TValue(int x)
+	{
+		this.x = x;
+		this.ptr = null;
+	}
+
+	internal TValue(uint x)
+	{
+		this.x = (int)x;
+		this.ptr = null;
+	}
+
+	internal TValue(bool b)
+	{
+		this.x = b ? -1 : 0;
+		this.ptr = null;
+	}
+
+	internal TValue(int x, TPointerBase ptr)
+	{
+		this.x = x;
+		this.ptr = ptr;
+	}
+
+	/*
+	 * Convert this value to a boolean; integer 0 and null pointer are
+	 * 'false', other values are 'true'.
+	 */
+	internal bool Bool {
+		get {
+			if (ptr == null) {
+				return x != 0;
+			} else {
+				return ptr.ToBool(this);
+			}
+		}
+	}
+
+	/*
+	 * Get this value as an integer. Pointers cannot be converted to
+	 * integers.
+	 */
+	internal int Int {
+		get {
+			if (ptr == null) {
+				return x;
+			}
+			throw new Exception("not an integer: " + ToString());
+		}
+	}
+
+	/*
+	 * Get this value as an unsigned integer. This is the integer
+	 * value, reduced modulo 2^32 in the 0..2^32-1 range.
+	 */
+	internal uint UInt {
+		get {
+			return (uint)Int;
+		}
+	}
+
+	/*
+	 * String format of integers uses decimal representation. For
+	 * pointers, this depends on the pointed-to value.
+	 */
+	public override string ToString()
+	{
+		if (ptr == null) {
+			return String.Format("{0}", x);
+		} else {
+			return ptr.ToString(this);
+		}
+	}
+
+	/*
+	 * If this value is an XT, then execute it. Otherwise, an exception
+	 * is thrown.
+	 */
+	internal void Execute(T0Comp ctx, CPU cpu)
+	{
+		ToXT().Execute(ctx, cpu);
+	}
+
+	/*
+	 * Convert this value to an XT. On failure, an exception is thrown.
+	 */
+	internal TPointerXT ToXT()
+	{
+		TPointerXT xt = ptr as TPointerXT;
+		if (xt == null) {
+			throw new Exception(
+				"value is not an xt: " + ToString());
+		}
+		return xt;
+	}
+
+	/*
+	 * Compare this value to another.
+	 */
+	internal bool Equals(TValue v)
+	{
+		if (x != v.x) {
+			return false;
+		}
+		if (ptr == v.ptr) {
+			return true;
+		}
+		if (ptr == null || v.ptr == null) {
+			return false;
+		}
+		return ptr.Equals(v.ptr);
+	}
+
+	public static implicit operator TValue(bool val)
+	{
+		return new TValue(val);
+	}
+
+	public static implicit operator TValue(sbyte val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(byte val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(short val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(ushort val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(char val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(int val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator TValue(uint val)
+	{
+		return new TValue((int)val);
+	}
+
+	public static implicit operator bool(TValue v)
+	{
+		return v.Bool;
+	}
+
+	public static implicit operator sbyte(TValue v)
+	{
+		return (sbyte)v.Int;
+	}
+
+	public static implicit operator byte(TValue v)
+	{
+		return (byte)v.Int;
+	}
+
+	public static implicit operator short(TValue v)
+	{
+		return (short)v.Int;
+	}
+
+	public static implicit operator ushort(TValue v)
+	{
+		return (ushort)v.Int;
+	}
+
+	public static implicit operator char(TValue v)
+	{
+		return (char)v.Int;
+	}
+
+	public static implicit operator int(TValue v)
+	{
+		return (int)v.Int;
+	}
+
+	public static implicit operator uint(TValue v)
+	{
+		return (uint)v.Int;
+	}
+}

T0/Word.cs

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * A "word" is a function with a name. Words can be either native or
+ * interpreted; native words are implemented as some in-compiler special
+ * code.
+ *
+ * Some native words (not all of them) have a C implementation and can
+ * thus be part of the generated C code. Native words with no C
+ * implementation can be used only during compilation; this is typically
+ * the case for words that support the syntax (e.g. 'if').
+ */
+
+abstract class Word {
+
+	/*
+	 * The compiler context for this word.
+	 */
+	internal T0Comp TC {
+		get; private set;
+	}
+
+	/*
+	 * Immediate words are executed immediately when encountered in the
+	 * source code, even while compiling another word.
+	 */
+	internal bool Immediate {
+		get; set;
+	}
+
+	/*
+	 * Each word has a unique name. Names are case-sensitive.
+	 */
+	internal string Name {
+		get; private set;
+	}
+
+	/*
+	 * Words are allocated slot numbers when output code is generated.
+	 */
+	internal int Slot {
+		get; set;
+	}
+
+	/*
+	 * Each word may have a known stack effect.
+	 */
+	internal SType StackEffect {
+		get; set;
+	}
+
+	internal Word(T0Comp owner, string name)
+	{
+		TC = owner;
+		Name = name;
+		StackEffect = SType.UNKNOWN;
+	}
+
+	/*
+	 * Resolving a word means looking up all references to external
+	 * words.
+	 */
+	internal virtual void Resolve()
+	{
+	}
+
+	/*
+	 * Execute this word. If the word is native, then its code is
+	 * run right away; if the word is interpreted, then the entry
+	 * sequence is executed.
+	 */
+	internal virtual void Run(CPU cpu)
+	{
+		throw new Exception(String.Format(
+			"cannot run '{0}' at compile-time", Name));
+	}
+
+	/*
+	 * All words may have an explicit C implementations. To be part
+	 * of the generated C code, a word must either be interpreted,
+	 * or have an explicit C implementation, or both.
+	 */
+	internal string CCode {
+		get; set;
+	}
+
+	/*
+	 * Get all words referenced from this one. This implies
+	 * resolving the word.
+	 */
+	internal virtual List<Word> GetReferences()
+	{
+		return new List<Word>();
+	}
+
+	/*
+	 * Get all data blocks directly referenced from this one. This
+	 * implies resolving the word.
+	 */
+	internal virtual List<ConstData> GetDataBlocks()
+	{
+		return new List<ConstData>();
+	}
+
+	/*
+	 * Produce the code elements for this word.
+	 */
+	internal virtual void GenerateCodeElements(List<CodeElement> dst)
+	{
+		throw new Exception("Word does not yield code elements");
+	}
+
+	/*
+	 * Compute/verify stack effect for this word.
+	 */
+	internal virtual void AnalyseFlow()
+	{
+	}
+
+	/*
+	 * Get maximum data stack usage for this word. This is the number
+	 * of extra slots that this word may need on the data stack. If
+	 * the stack effect is not known, this returns -1.
+	 */
+	internal virtual int MaxDataStack {
+		get {
+			SType se = StackEffect;
+			if (!se.IsKnown) {
+				return -1;
+			}
+			if (se.NoExit) {
+				return 0;
+			} else {
+				return Math.Min(0, se.DataOut - se.DataIn);
+			}
+		}
+	}
+
+	/*
+	 * Get maximum return stack usage for this word.
+	 */
+	internal virtual int MaxReturnStack {
+		get {
+			return 0;
+		}
+	}
+}

T0/WordBuilder.cs

@@ -0,0 +1,385 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * A WordBuilder instance organizes construction of a new interpreted word.
+ *
+ * Opcodes are accumulated with specific methods. A control-flow stack
+ * is maintained to resolve jumps.
+ *
+ * Each instance shall be used for only one word.
+ */
+
+class WordBuilder {
+
+	T0Comp TC;
+	string name;
+	int[] cfStack;
+	int cfPtr;
+	List<Opcode> code;
+	List<string> toResolve;
+	Dictionary<string, int> locals;
+	bool jumpToLast;
+
+	internal SType StackEffect {
+		get; set;
+	}
+
+	/*
+	 * Create a new instance, with the specified word name.
+	 */
+	internal WordBuilder(T0Comp TC, string name)
+	{
+		this.TC = TC;
+		this.name = name;
+		cfStack = new int[16];
+		cfPtr = -1;
+		code = new List<Opcode>();
+		toResolve = new List<string>();
+		locals = new Dictionary<string, int>();
+		jumpToLast = true;
+		StackEffect = SType.UNKNOWN;
+	}
+
+	/*
+	 * Build the word. The control-flow stack must be empty. A 'ret'
+	 * opcode is automatically appended if required.
+	 */
+	internal Word Build()
+	{
+		if (cfPtr != -1) {
+			throw new Exception("control-flow stack is not empty");
+		}
+		if (jumpToLast || code[code.Count - 1].MayFallThrough) {
+			Ret();
+		}
+		Word w = new WordInterpreted(TC, name, locals.Count,
+			code.ToArray(), toResolve.ToArray());
+		w.StackEffect = StackEffect;
+		return w;
+	}
+
+	void Add(Opcode op)
+	{
+		Add(op, null);
+	}
+
+	void Add(Opcode op, string refName)
+	{
+		code.Add(op);
+		toResolve.Add(refName);
+		jumpToLast = false;
+	}
+
+	/*
+	 * Rotate the control-flow stack at depth 'depth'.
+	 */
+	internal void CSRoll(int depth)
+	{
+		int x = cfStack[cfPtr - depth];
+		Array.Copy(cfStack, cfPtr - (depth - 1),
+			cfStack, cfPtr - depth, depth);
+		cfStack[cfPtr] = x;
+	}
+
+	/*
+	 * Make a copy of the control-flow element at depth 'depth', and
+	 * push it on top of the control-flow stack.
+	 */
+	internal void CSPick(int depth)
+	{
+		int x = cfStack[cfPtr - depth];
+		CSPush(x);
+	}
+
+	void CSPush(int x)
+	{
+		int len = cfStack.Length;
+		if (++ cfPtr == len) {
+			int[] ncf = new int[len << 1];
+			Array.Copy(cfStack, 0, ncf, 0, len);
+			cfStack = ncf;
+		}
+		cfStack[cfPtr] = x;
+	}
+
+	int CSPop()
+	{
+		return cfStack[cfPtr --];
+	}
+
+	/*
+	 * Push an origin on the control-flow stack, corresponding to the
+	 * next opcode to add.
+	 */
+	internal void CSPushOrig()
+	{
+		CSPush(code.Count);
+	}
+
+	/*
+	 * Push a destination on the control-flow stack, corresponding to
+	 * the next opcode to add.
+	 */
+	internal void CSPushDest()
+	{
+		CSPush(-code.Count - 1);
+	}
+
+	/*
+	 * Pop an origin from the control-flow stack. An exception is
+	 * thrown if the value is not an origin.
+	 */
+	internal int CSPopOrig()
+	{
+		int x = CSPop();
+		if (x < 0) {
+			throw new Exception("not an origin");
+		}
+		return x;
+	}
+
+	/*
+	 * Pop a destination from the control-flow stack. An exception is
+	 * thrown if the value is not a destination.
+	 */
+	internal int CSPopDest()
+	{
+		int x = CSPop();
+		if (x >= 0) {
+			throw new Exception("not a destination");
+		}
+		return -x - 1;
+	}
+
+	/*
+	 * Add a "push literal" opcode.
+	 */
+	internal void Literal(TValue v)
+	{
+		Add(new OpcodeConst(v));
+	}
+
+	/*
+	 * Compile a "call" by name. This method implements the support
+	 * for local variables:
+	 *
+	 *  - If the target is '>' followed by a local variable name, then
+	 *    a "put local" opcode is added.
+	 *
+	 *  - Otherwise, if the target is a local variable name, then a
+	 *    "get local" opcode is added.
+	 *
+	 *  - Otherwise, a call to the named word is added. The target name
+	 *    will be resolved later on (typically, when the word containing
+	 *    the call opcode is first invoked, or when C code is generated).
+	 */
+	internal void Call(string target)
+	{
+		string lname;
+		bool write;
+		if (target.StartsWith(">")) {
+			lname = target.Substring(1);
+			write = true;
+		} else {
+			lname = target;
+			write = false;
+		}
+		int lnum;
+		if (locals.TryGetValue(lname, out lnum)) {
+			if (write) {
+				Add(new OpcodePutLocal(lnum));
+			} else {
+				Add(new OpcodeGetLocal(lnum));
+			}
+		} else {
+			Add(new OpcodeCall(), target);
+		}
+	}
+
+	/*
+	 * Add a "call" opcode to the designated word.
+	 */
+	internal void CallExt(Word wtarget)
+	{
+		Add(new OpcodeCall(wtarget), null);
+	}
+
+	/*
+	 * Add a "call" opcode to a word which is not currently resolved.
+	 * This method ignores local variables.
+	 */
+	internal void CallExt(string target)
+	{
+		Add(new OpcodeCall(), target);
+	}
+
+	/*
+	 * Add a "get local" opcode; the provided local name must already
+	 * be defined.
+	 */
+	internal void GetLocal(string name)
+	{
+		int lnum;
+		if (locals.TryGetValue(name, out lnum)) {
+			Add(new OpcodeGetLocal(lnum));
+		} else {
+			throw new Exception("no such local: " + name);
+		}
+	}
+
+	/*
+	 * Add a "put local" opcode; the provided local name must already
+	 * be defined.
+	 */
+	internal void PutLocal(string name)
+	{
+		int lnum;
+		if (locals.TryGetValue(name, out lnum)) {
+			Add(new OpcodePutLocal(lnum));
+		} else {
+			throw new Exception("no such local: " + name);
+		}
+	}
+
+	/*
+	 * Define a new local name.
+	 */
+	internal void DefLocal(string lname)
+	{
+		if (locals.ContainsKey(lname)) {
+			throw new Exception(String.Format(
+				"local already defined: {0}", lname));
+		}
+		locals[lname] = locals.Count;
+	}
+
+	/*
+	 * Add a "call" opcode whose target is an XT value (which may be
+	 * resolved or as yet unresolved).
+	 */
+	internal void Call(TPointerXT xt)
+	{
+		if (xt.Target == null) {
+			Add(new OpcodeCall(), xt.Name);
+		} else {
+			Add(new OpcodeCall(xt.Target));
+		}
+	}
+
+	/*
+	 * Add a "ret" opcode.
+	 */
+	internal void Ret()
+	{
+		Add(new OpcodeRet());
+	}
+
+	/*
+	 * Add a forward unconditional jump. The new opcode address is
+	 * pushed on the control-flow stack as an origin.
+	 */
+	internal void Ahead()
+	{
+		CSPushOrig();
+		Add(new OpcodeJumpUncond());
+	}
+
+	/*
+	 * Add a forward conditional jump, which will be taken at runtime
+	 * if the top-of-stack value is 'true'. The new opcode address is
+	 * pushed on the control-flow stack as an origin.
+	 */
+	internal void AheadIf()
+	{
+		CSPushOrig();
+		Add(new OpcodeJumpIf());
+	}
+
+	/*
+	 * Add a forward conditional jump, which will be taken at runtime
+	 * if the top-of-stack value is 'false'. The new opcode address is
+	 * pushed on the control-flow stack as an origin.
+	 */
+	internal void AheadIfNot()
+	{
+		CSPushOrig();
+		Add(new OpcodeJumpIfNot());
+	}
+
+	/*
+	 * Resolve a previous forward jump to the current code address.
+	 * The top of control-flow stack is popped and must be an origin.
+	 */
+	internal void Then()
+	{
+		int x = CSPopOrig();
+		code[x].ResolveJump(code.Count - x - 1);
+		jumpToLast = true;
+	}
+
+	/*
+	 * Push the current code address on the control-flow stack as a
+	 * destination, to be used by an ulterior backward jump.
+	 */
+	internal void Begin()
+	{
+		CSPushDest();
+	}
+
+	/*
+	 * Add a backward unconditional jump. The jump target is popped
+	 * from the control-flow stack as a destination.
+	 */
+	internal void Again()
+	{
+		int x = CSPopDest();
+		Add(new OpcodeJumpUncond(x - code.Count - 1));
+	}
+
+	/*
+	 * Add a backward conditional jump, which will be taken at runtime
+	 * if the top-of-stack value is 'true'. The jump target is popped
+	 * from the control-flow stack as a destination.
+	 */
+	internal void AgainIf()
+	{
+		int x = CSPopDest();
+		Add(new OpcodeJumpIf(x - code.Count - 1));
+	}
+
+	/*
+	 * Add a backward conditional jump, which will be taken at runtime
+	 * if the top-of-stack value is 'false'. The jump target is popped
+	 * from the control-flow stack as a destination.
+	 */
+	internal void AgainIfNot()
+	{
+		int x = CSPopDest();
+		Add(new OpcodeJumpIfNot(x - code.Count - 1));
+	}
+}

T0/WordData.cs

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+class WordData : Word {
+
+	ConstData blob;
+	string baseBlobName;
+	int offset;
+	bool ongoingResolution;
+
+	internal WordData(T0Comp owner, string name,
+		ConstData blob, int offset)
+		: base(owner, name)
+	{
+		this.blob = blob;
+		this.offset = offset;
+		StackEffect = new SType(0, 1);
+	}
+
+	internal WordData(T0Comp owner, string name,
+		string baseBlobName, int offset)
+		: base(owner, name)
+	{
+		this.baseBlobName = baseBlobName;
+		this.offset = offset;
+		StackEffect = new SType(0, 1);
+	}
+
+	internal override void Resolve()
+	{
+		if (blob != null) {
+			return;
+		}
+		if (ongoingResolution) {
+			throw new Exception(String.Format(
+				"circular reference in blobs ({0})", Name));
+		}
+		ongoingResolution = true;
+		WordData wd = TC.Lookup(baseBlobName) as WordData;
+		if (wd == null) {
+			throw new Exception(String.Format(
+				"data word '{0}' based on non-data word '{1}'",
+				Name, baseBlobName));
+		}
+		wd.Resolve();
+		blob = wd.blob;
+		offset += wd.offset;
+		ongoingResolution = false;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		Resolve();
+		cpu.Push(new TValue(offset, new TPointerBlob(blob)));
+	}
+
+	internal override List<ConstData> GetDataBlocks()
+	{
+		Resolve();
+		List<ConstData> r = new List<ConstData>();
+		r.Add(blob);
+		return r;
+	}
+
+	internal override void GenerateCodeElements(List<CodeElement> dst)
+	{
+		Resolve();
+		dst.Add(new CodeElementUInt(0));
+		dst.Add(new CodeElementUIntInt(1, blob.Address + offset));
+		dst.Add(new CodeElementUInt(0));
+	}
+}

T0/WordInterpreted.cs

@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * The implementation for interpreted words.
+ */
+
+class WordInterpreted : Word {
+
+	/*
+	 * Get the number of local variables for this word.
+	 */
+	internal int NumLocals {
+		get; private set;
+	}
+
+	/*
+	 * Get the sequence of opcodes for this word.
+	 */
+	internal Opcode[] Code {
+		get; private set;
+	}
+
+	string[] toResolve;
+
+	internal WordInterpreted(T0Comp owner, string name,
+		int numLocals, Opcode[] code, string[] toResolve)
+		: base(owner, name)
+	{
+		this.Code = code;
+		this.toResolve = toResolve;
+		NumLocals = numLocals;
+	}
+
+	internal override void Resolve()
+	{
+		if (toResolve == null) {
+			return;
+		}
+		for (int i = 0; i < toResolve.Length; i ++) {
+			string tt = toResolve[i];
+			if (tt == null) {
+				continue;
+			}
+			Code[i].ResolveTarget(TC.Lookup(tt));
+		}
+		toResolve = null;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		Resolve();
+		cpu.Enter(Code, NumLocals);
+	}
+
+	internal override List<Word> GetReferences()
+	{
+		Resolve();
+		List<Word> r = new List<Word>();
+		foreach (Opcode op in Code) {
+			Word w = op.GetReference(TC);
+			if (w != null) {
+				r.Add(w);
+			}
+		}
+		return r;
+	}
+
+	internal override List<ConstData> GetDataBlocks()
+	{
+		Resolve();
+		List<ConstData> r = new List<ConstData>();
+		foreach (Opcode op in Code) {
+			ConstData cd = op.GetDataBlock(TC);
+			if (cd != null) {
+				r.Add(cd);
+			}
+		}
+		return r;
+	}
+
+	internal override void GenerateCodeElements(List<CodeElement> dst)
+	{
+		Resolve();
+		int n = Code.Length;
+		CodeElement[] gcode = new CodeElement[n];
+		for (int i = 0; i < n; i ++) {
+			gcode[i] = Code[i].ToCodeElement();
+		}
+		for (int i = 0; i < n; i ++) {
+			Code[i].FixUp(gcode, i);
+		}
+		dst.Add(new CodeElementUInt((uint)NumLocals));
+		for (int i = 0; i < n; i ++) {
+			dst.Add(gcode[i]);
+		}
+	}
+
+	int flowAnalysis;
+	int maxDataStack;
+	int maxReturnStack;
+
+	bool MergeSA(int[] sa, int j, int c)
+	{
+		if (sa[j] == Int32.MinValue) {
+			sa[j] = c;
+			return true;
+		} else if (sa[j] != c) {
+			throw new Exception(string.Format(
+				"In word '{0}', offset {1}:"
+				+ " stack action mismatch ({2} / {3})",
+				Name, j, sa[j], c));
+		} else {
+			return false;
+		}
+	}
+
+	internal override void AnalyseFlow()
+	{
+		switch (flowAnalysis) {
+		case 0:
+			break;
+		case 1:
+			return;
+		default:
+			throw new Exception("recursive call detected in '"
+				+ Name + "'");
+		}
+		flowAnalysis = 2;
+		int n = Code.Length;
+		int[] sa = new int[n];
+		for (int i = 0; i < n; i ++) {
+			sa[i] = Int32.MinValue;
+		}
+		sa[0] = 0;
+		int[] toExplore = new int[n];
+		int tX = 0, tY = 0;
+		int off = 0;
+
+		int exitSA = Int32.MinValue;
+		int mds = 0;
+		int mrs = 0;
+
+		int maxDepth = 0;
+
+		for (;;) {
+			Opcode op = Code[off];
+			bool mft = op.MayFallThrough;
+			int c = sa[off];
+			int a;
+			if (op is OpcodeCall) {
+				Word w = op.GetReference(TC);
+				w.AnalyseFlow();
+				SType se = w.StackEffect;
+				if (!se.IsKnown) {
+					throw new Exception(string.Format(
+						"call from '{0}' to '{1}'"
+						+ " with unknown stack effect",
+						Name, w.Name));
+				}
+				if (se.NoExit) {
+					mft = false;
+					a = 0;
+				} else {
+					a = se.DataOut - se.DataIn;
+				}
+				mds = Math.Max(mds, c + w.MaxDataStack);
+				mrs = Math.Max(mrs, w.MaxReturnStack);
+				maxDepth = Math.Min(maxDepth, c - se.DataIn);
+			} else if (op is OpcodeRet) {
+				if (exitSA == Int32.MinValue) {
+					exitSA = c;
+				} else if (exitSA != c) {
+					throw new Exception(string.Format(
+						"'{0}': exit stack action"
+						+ " mismatch: {1} / {2}"
+						+ " (offset {3})",
+						Name, exitSA, c, off));
+				}
+				a = 0;
+			} else {
+				a = op.StackAction;
+				mds = Math.Max(mds, c + a);
+			}
+			c += a;
+			maxDepth = Math.Min(maxDepth, c);
+
+			int j = op.JumpDisp;
+			if (j != 0) {
+				j += off + 1;
+				toExplore[tY ++] = j;
+				MergeSA(sa, j, c);
+			}
+			off ++;
+			if (!mft || !MergeSA(sa, off, c)) {
+				if (tX < tY) {
+					off = toExplore[tX ++];
+				} else {
+					break;
+				}
+			}
+		}
+
+		maxDataStack = mds;
+		maxReturnStack = 1 + NumLocals + mrs;
+
+		/*
+		 * TODO: see about this warning. Usage of a 'fail'
+		 * word (that does not exit) within a 'case..endcase'
+		 * structure will make an unreachable opcode. In a future
+		 * version we might want to automatically remove dead
+		 * opcodes.
+		for (int i = 0; i < n; i ++) {
+			if (sa[i] == Int32.MinValue) {
+				Console.WriteLine("warning: word '{0}',"
+					+ " offset {1}: unreachable opcode",
+					Name, i);
+				continue;
+			}
+		}
+		 */
+
+		SType computed;
+		if (exitSA == Int32.MinValue) {
+			computed = new SType(-maxDepth, -1);
+		} else {
+			computed = new SType(-maxDepth, -maxDepth + exitSA);
+		}
+
+		if (StackEffect.IsKnown) {
+			if (!computed.IsSubOf(StackEffect)) {
+				throw new Exception(string.Format(
+					"word '{0}':"
+					+ " computed stack effect {1}"
+					+ " does not match declared {2}",
+					Name, computed.ToString(),
+					StackEffect.ToString()));
+			}
+		} else {
+			StackEffect = computed;
+		}
+
+		flowAnalysis = 1;
+	}
+
+	internal override int MaxDataStack {
+		get {
+			AnalyseFlow();
+			return maxDataStack;
+		}
+	}
+
+	internal override int MaxReturnStack {
+		get {
+			AnalyseFlow();
+			return maxReturnStack;
+		}
+	}
+}

T0/WordNative.cs

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+
+/*
+ * Class for native words.
+ */
+
+class WordNative : Word {
+
+	/*
+	 * A type for the native implementation: a method that takes a
+	 * CPU as parameter, and returns nothing.
+	 */
+	internal delegate void NativeRun(CPU cpu);
+
+	NativeRun code;
+
+	internal WordNative(T0Comp owner, string name, NativeRun code)
+		: base(owner, name)
+	{
+		this.code = code;
+	}
+
+	internal WordNative(T0Comp owner, string name,
+		SType stackEffect, NativeRun code)
+		: this(owner, name, code)
+	{
+		StackEffect = stackEffect;
+	}
+
+	internal override void Run(CPU cpu)
+	{
+		code(cpu);
+	}
+}

T0/kern.t0

@@ -0,0 +1,309 @@
+: \ `\n parse drop ; immediate
+
+\ This file defines the core non-native functions (mainly used for
+\ parsing words, i.e. not part of the generated output). The line above
+\ defines the syntax for comments.
+
+\ Define parenthesis comments.
+\ : ( `) parse drop ; immediate
+
+: else postpone ahead 1 cs-roll postpone then ; immediate
+: while postpone if 1 cs-roll ; immediate
+: repeat postpone again postpone then ; immediate
+
+: ['] ' ; immediate
+: [compile] compile ; immediate
+
+: 2drop drop drop ;
+: dup2 over over ;
+
+\ Local variables are defined with the native word '(local)'. We define
+\ a helper construction that mimics what is found in Apple's Open Firmware
+\ implementation. The syntax is: { a b ... ; c d ... }
+\ I.e. there is an opening brace, then some names. Names appearing before
+\ the semicolon are locals that are both defined and then filled with the
+\ values on stack (in stack order: { a b } fills 'b' with the top-of-stack,
+\ and 'a' with the value immediately below). Names appearing after the
+\ semicolon are not initialized.
+: __deflocal ( from_stack name -- )
+	dup (local) swap if
+		compile-local-write
+	else
+		drop
+	then ;
+: __deflocals ( from_stack -- )
+	next-word
+	dup "}" eqstr if
+		2drop ret
+	then
+	dup ";" eqstr if
+		2drop 0 __deflocals ret
+	then
+	over __deflocals
+	__deflocal ;
+: {
+	-1 __deflocals ; immediate
+
+\ Data building words.
+: data:
+	new-data-block next-word define-data-word ;
+: hexb|
+	0 0 { acc z }
+	begin
+		char
+		dup `| = if
+			z if "Truncated hexadecimal byte" puts cr exitvm then
+			ret
+		then
+		dup 0x20 > if
+			hexval
+			z if acc 4 << + data-add8 else >acc then
+			z not >z
+		then
+	again ;
+
+\ Convert hexadecimal character to number. Complain loudly if conversion
+\ is not possible.
+: hexval ( char -- x )
+	hexval-nf dup 0 < if "Not an hex digit: " puts . cr exitvm then ;
+
+\ Convert hexadecimal character to number. If not an hexadecimal digit,
+\ return -1.
+: hexval-nf ( char -- x )
+	dup dup `0 >= swap `9 <= and if `0 - ret then
+	dup dup `A >= swap `F <= and if `A - 10 + ret then
+	dup dup `a >= swap `f <= and if `a - 10 + ret then
+	drop -1 ;
+
+\ Convert decimal character to number. Complain loudly if conversion
+\ is not possible.
+: decval ( char -- x )
+	decval-nf dup 0 < if "Not a decimal digit: " puts . cr exitvm then ;
+
+\ Convert decimal character to number. If not a decimal digit,
+\ return -1.
+: decval-nf ( char -- x )
+	dup dup `0 >= swap `9 <= and if `0 - ret then
+	drop -1 ;
+
+\ Commonly used shorthands.
+: 1+ 1 + ;
+: 2+ 2 + ;
+: 1- 1 - ;
+: 2- 2 - ;
+: 0= 0 = ;
+: 0<> 0 <> ;
+: 0< 0 < ;
+: 0> 0 > ;
+
+\ Get a 16-bit value from the constant data block. This uses big-endian
+\ encoding.
+: data-get16 ( addr -- x )
+	dup data-get8 8 << swap 1+ data-get8 + ;
+
+\ The case..endcase construction is the equivalent of 'switch' is C.
+\ Usage:
+\     case
+\         E1 of C1 endof
+\         E2 of C2 endof
+\         ...
+\         CN
+\     endcase
+\
+\ Upon entry, it considers the TOS (let's call it X). It will then evaluate
+\ E1, which should yield a single value Y1; at that point, the X value is
+\ still on the stack, just below Y1, and must remain untouched. The 'of'
+\ word compares X with Y1; if they are equal, C1 is executed, and then
+\ control jumps to after the 'endcase'. The X value is popped from the
+\ stack immediately before evaluating C1.
+\
+\ If X and Y1 are not equal, flow proceeds to E2, to obtain a value Y2 to
+\ compare with X. And so on.
+\
+\ If none of the 'of' clauses found a match, then CN is evaluated. When CN
+\ is evaluated, the X value is on the TOS, and CN must either leave it on
+\ the stack, or replace it with exactly one value; the 'endcase' word
+\ expects (and drops) one value.
+\
+\ Implementation: this is mostly copied from ANS Forth specification,
+\ although simplified a bit because we know that our control-flow stack
+\ is independent of the data stack. During compilation, the number of
+\ clauses is maintained on the stack; each of..endof clause really is
+\ an 'if..else' that must be terminated with a matching 'then' in 'endcase'.
+
+: case 0 ; immediate
+: of 1+ postpone over postpone = postpone if postpone drop ; immediate
+: endof postpone else ; immediate
+: endcase
+	postpone drop
+	begin dup while 1- postpone then repeat drop ; immediate
+
+\ A simpler and more generic "case": there is no management for a value
+\ on the stack, and each test is supposed to come up with its own boolean
+\ value.
+: choice 0 ; immediate
+: uf 1+ postpone if ; immediate
+: ufnot 1+ postpone ifnot ; immediate
+: enduf postpone else ; immediate
+: endchoice begin dup while 1- postpone then repeat drop ; immediate
+
+\ C implementations for native words that can be used in generated code.
+add-cc: co { T0_CO(); }
+add-cc: execute { T0_ENTER(ip, rp, T0_POP()); }
+add-cc: drop { (void)T0_POP(); }
+add-cc: dup { T0_PUSH(T0_PEEK(0)); }
+add-cc: swap { T0_SWAP(); }
+add-cc: over { T0_PUSH(T0_PEEK(1)); }
+add-cc: rot { T0_ROT(); }
+add-cc: -rot { T0_NROT(); }
+add-cc: roll { T0_ROLL(T0_POP()); }
+add-cc: pick { T0_PICK(T0_POP()); }
+add-cc: + {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a + b);
+}
+add-cc: - {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a - b);
+}
+add-cc: neg {
+	uint32_t a = T0_POP();
+	T0_PUSH(-a);
+}
+add-cc: * {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a * b);
+}
+add-cc: / {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSHi(a / b);
+}
+add-cc: u/ {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a / b);
+}
+add-cc: % {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSHi(a % b);
+}
+add-cc: u% {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a % b);
+}
+add-cc: < {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSH(-(uint32_t)(a < b));
+}
+add-cc: <= {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSH(-(uint32_t)(a <= b));
+}
+add-cc: > {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSH(-(uint32_t)(a > b));
+}
+add-cc: >= {
+	int32_t b = T0_POPi();
+	int32_t a = T0_POPi();
+	T0_PUSH(-(uint32_t)(a >= b));
+}
+add-cc: = {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a == b));
+}
+add-cc: <> {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a != b));
+}
+add-cc: u< {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a < b));
+}
+add-cc: u<= {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a <= b));
+}
+add-cc: u> {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a > b));
+}
+add-cc: u>= {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(-(uint32_t)(a >= b));
+}
+add-cc: and {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a & b);
+}
+add-cc: or {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a | b);
+}
+add-cc: xor {
+	uint32_t b = T0_POP();
+	uint32_t a = T0_POP();
+	T0_PUSH(a ^ b);
+}
+add-cc: not {
+	uint32_t a = T0_POP();
+	T0_PUSH(~a);
+}
+add-cc: << {
+	int c = (int)T0_POPi();
+	uint32_t x = T0_POP();
+	T0_PUSH(x << c);
+}
+add-cc: >> {
+	int c = (int)T0_POPi();
+	int32_t x = T0_POPi();
+	T0_PUSHi(x >> c);
+}
+add-cc: u>> {
+	int c = (int)T0_POPi();
+	uint32_t x = T0_POP();
+	T0_PUSH(x >> c);
+}
+add-cc: data-get8 {
+	size_t addr = T0_POP();
+	T0_PUSH(t0_datablock[addr]);
+}
+
+add-cc: . {
+	extern int printf(const char *fmt, ...);
+	printf(" %ld", (long)T0_POPi());
+}
+add-cc: putc {
+	extern int printf(const char *fmt, ...);
+	printf("%c", (char)T0_POPi());
+}
+add-cc: puts {
+	extern int printf(const char *fmt, ...);
+	printf("%s", &t0_datablock[T0_POPi()]);
+}
+add-cc: cr {
+	extern int printf(const char *fmt, ...);
+	printf("\n");
+}
+add-cc: eqstr {
+	const void *b = &t0_datablock[T0_POPi()];
+	const void *a = &t0_datablock[T0_POPi()];
+	T0_PUSH(-(int32_t)(strcmp(a, b) == 0));
+}