/*
    disassembler.c -- Byte compiler and function evaluator
*/
/*
    Copyright (c) 2001, Juan Jose Garcia Ripoll.

    ECL is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    See file '../Copyright' for full details.
*/

#include "ecl.h"
#include "ecl-inl.h"
#include "bytecodes.h"

static cl_opcode *disassemble(cl_object bytecodes, cl_opcode *vector);

static cl_opcode *base = NULL;

static void
print_noarg(const char *s) {
	princ_str(s, Cnil);
}

static void
print_oparg(const char *s, cl_fixnum n) {
	princ_str(s, Cnil);
	princ(MAKE_FIXNUM(n), Cnil);
}

static void
print_arg(const char *s, cl_object x) {
	princ_str(s, Cnil);
	princ(x, Cnil);
}

static void
print_oparg_arg(const char *s, cl_fixnum n, cl_object x) {
	princ_str(s, Cnil);
	princ(MAKE_FIXNUM(n), Cnil);
	princ_str(",", Cnil);
	princ(x, Cnil);
}

static cl_object *
disassemble_vars(const char *message, cl_object *data, cl_index step) {
	cl_object o = *(data++);
	cl_index n = fix(o);

	if (n) {
	  terpri(Cnil);
	  print_noarg(message);
	  for (; n; n--, data+=step) {
	    prin1(data[0], Cnil);
	    if (n > 1) print_noarg(", ");
	  }
	}
	return data;
}

static void
disassemble_lambda(cl_object bytecodes) {
	cl_object *data;
	cl_opcode *vector;

	/* Name of LAMBDA */
	print_arg("\nName:\t\t", bytecodes->bytecodes.name);

	/* Print required arguments */
	data = bytecodes->bytecodes.data;
	data = disassemble_vars("Required:\t", data, 1);

	/* Print optional arguments */
	data = disassemble_vars("Optionals:\t", data, 3);

	/* Print rest argument */
	if (data[0] != Cnil) {
		print_arg("\nRest:\t\t", data[0]);
	}
	data++;

	/* Print keyword arguments */
	if (data[0] == MAKE_FIXNUM(0)) {
		data++;
		goto NO_KEYS;
	}
	if (data[0] != Cnil) {
		print_arg("\nOther keys:\t", data[0]);
	}
	data++;
	data = disassemble_vars("Keywords:\t", data, 4);
NO_KEYS:
	/* Print aux arguments */
	print_arg("\nDocumentation:\t", *(data++));
	print_arg("\nDeclarations:\t", *(data++));

	base = vector = (cl_opcode *)bytecodes->bytecodes.code;
	disassemble(bytecodes, vector);
}

/* -------------------- DISASSEMBLER CORE -------------------- */

/* OP_DOLIST	labelz, labelo
   ...		; code to bind the local variable
   OP_EXIT
   ...		; code executed on each iteration
   OP_EXIT
   labelo:
   ...		; code executed at the end
   OP_EXIT
   labelz:

	High level construct for the DOLIST iterator. The list over which
	we iterate is stored in VALUES(0).
*/
static cl_opcode *
disassemble_dolist(cl_object bytecodes, cl_opcode *vector) {
	cl_opcode *exit, *output;
	cl_object lex_old = cl_env.lex_env;

	GET_LABEL(exit, vector);
	GET_LABEL(output, vector);
	print_oparg("DOLIST\t", exit-base);
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dolist binding");
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dolist body");
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dolist");

	cl_env.lex_env = lex_old;
	return vector;
}

/* OP_TIMES	labelz, labelo
   ...		; code to bind the local variable
   OP_EXIT
   ...		; code executed on each iteration
   OP_EXIT
   labelo:
   ...		; code executed at the end
   OP_EXIT
   labelz:

	High level construct for the DOTIMES iterator. The number of times
	we iterate is stored in VALUES(0).
*/
static cl_opcode *
disassemble_dotimes(cl_object bytecodes, cl_opcode *vector) {
	cl_opcode *exit, *output;
	cl_object lex_old = cl_env.lex_env;

	GET_LABEL(exit, vector);
	GET_LABEL(output, vector);
	print_oparg("DOTIMES\t", exit-base);
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dotimes times");
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dotimes body");
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; dotimes");

	cl_env.lex_env = lex_old;
	return vector;
}

/* OP_FLET	nfun{arg}
   fun1{object}
   ...
   funn{object}
   ...

	Executes the enclosed code in a lexical enviroment extended with
	the functions "fun1" ... "funn".
*/
static cl_opcode *
disassemble_flet(cl_object bytecodes, cl_opcode *vector) {
	cl_index nfun = GET_OPARG(vector);
	print_noarg("FLET");
	while (nfun--) {
		cl_object fun = GET_DATA(vector, bytecodes);
		print_arg("\n\tFLET\t", fun->bytecodes.name);
	}
	return vector;
}

/* OP_LABELS	nfun{arg}
   fun1{object}
   ...
   funn{object}
   ...

	Executes the enclosed code in a lexical enviroment extended with
	the functions "fun1" ... "funn".
*/
static cl_opcode *
disassemble_labels(cl_object bytecodes, cl_opcode *vector) {
	cl_index nfun = GET_OPARG(vector);
	print_noarg("LABELS");
	while (nfun--) {
		cl_object fun = GET_DATA(vector, bytecodes);
		print_arg("\n\tLABELS\t", fun->bytecodes.name);
	}
	return vector;
}

/* OP_MSETQ	n{arg}
   {fixnumn}
   ...
   {fixnum1}

	Sets N variables to the N values in VALUES(), filling with
	NIL when there are values missing. Local variables are denoted
	with an integer which points a position in the lexical environment,
	while special variables are denoted with a negative index X, which
	denotes the value -1-X in the table of constants.
*/
static cl_opcode *
disassemble_msetq(cl_object bytecodes, cl_opcode *vector)
{
	int i, n = GET_OPARG(vector);
	bool newline = FALSE;

	for (i=0; i<n; i++) {
		cl_fixnum var = GET_OPARG(vector);
		if (newline) {
			print_noarg("\n\t");
		} else
			newline = TRUE;
		if (var >= 0) {
			cl_format(4, Ct,
				  make_constant_string("MSETQ\t~D,VALUES(~D)"),
				  MAKE_FIXNUM(var), MAKE_FIXNUM(i));
		} else {
			cl_object name = bytecodes->bytecodes.data[-1-var];
			cl_format(4, Ct,
				  make_constant_string("MSETQS\t~A,VALUES(~D)"),
				  name, MAKE_FIXNUM(i));
		}
	}
	return vector;
}


/* OP_PROGV	bindings{list}
   ...
   OP_EXIT
	Execute the code enclosed with the special variables in BINDINGS
	set to the values in the list which was passed in VALUES(0).
*/
static cl_opcode *
disassemble_progv(cl_object bytecodes, cl_opcode *vector) {
	print_noarg("PROGV");
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; progv");
	return vector;
}

/* OP_TAGBODY	n{arg}
   label1
   ...
   labeln
label1:
   ...
labeln:
   ...
   OP_EXIT

	High level construct for the TAGBODY form.
*/
static cl_opcode *
disassemble_tagbody(cl_object bytecodes, cl_opcode *vector) {
	cl_index i, ntags = GET_OPARG(vector);
	cl_object lex_old = cl_env.lex_env;
	cl_opcode *destination;

	print_noarg("TAGBODY");
	for (i=0; i<ntags; i++) {
		GET_LABEL(destination, vector);
		cl_format(4, Ct,
			  make_constant_string("\n\tTAG\t~D @@ ~D"),
			  MAKE_FIXNUM(i), MAKE_FIXNUM(destination-base));
	}
	vector = disassemble(bytecodes, vector);
	print_noarg("\t\t; tagbody");

	cl_env.lex_env = lex_old;
	return vector;
}

static cl_opcode *
disassemble(cl_object bytecodes, cl_opcode *vector) {
	const char *string;
	cl_object o;
	cl_fixnum n;
	cl_object line_format = make_constant_string("~%~4d\t");

 BEGIN:
	cl_format(3, Ct, line_format, MAKE_FIXNUM(vector-base));
	switch (GET_OPCODE(vector)) {

	/* OP_NOP
		Sets VALUES(0) = NIL and NVALUES = 1
	*/
	case OP_NOP:		string = "NOP";	goto NOARG;

	/* OP_QUOTE
		Sets VALUES(0) to an immediate value.
	*/
	case OP_QUOTE:		string = "QUOTE\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_VAR	n{arg}
		Sets NVALUES=1 and VALUES(0) to the value of the n-th local.
	*/
	case OP_VAR:		string = "VAR\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_VARS	var{symbol}
		Sets NVALUES=1 and VALUES(0) to the value of the symbol VAR.
		VAR should be either a special variable or a constant.
	*/
	case OP_VARS:		string = "VARS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_PUSH
		Pushes the object in VALUES(0).
	*/
	case OP_PUSH:		string = "PUSH\tVALUES(0)";
				goto NOARG;

	case OP_VALUEREG0:	string = "SET\tVALUES(0),REG0";
				goto NOARG;

	/* OP_PUSHV	n{arg}
		Pushes the value of the n-th local onto the stack.
	*/
	case OP_PUSHV:		string = "PUSHV\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_PUSHVS	var{symbol}
		Pushes the value of the symbol VAR onto the stack.
		VAR should be either a special variable or a constant.
	*/
	case OP_PUSHVS:		string = "PUSHVS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_PUSHQ	value{object}
		Pushes "value" onto the stack.
	*/
	case OP_PUSHQ:		string = "PUSH\t'";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_PUSHVALUES
		Pushes the values output by the last form, plus the number
		of values.
	*/
	case OP_PUSHVALUES:	string = "PUSH\tVALUES";
				goto NOARG;
	/* OP_PUSHMOREVALUES
		Adds more values to the ones pushed by OP_PUSHVALUES.
	*/
	case OP_PUSHMOREVALUES:	string = "PUSH\tMORE VALUES";
				goto NOARG;
	/* OP_POP
		Pops a single value pushed by a OP_PUSH[V[S]] operator.
	*/
	case OP_POP:		string = "POP";
				goto NOARG;
	/* OP_POPVALUES
		Pops all values pushed by a OP_PUSHVALUES operator.
	*/
	case OP_POPVALUES:	string = "POP\tVALUES";
				goto NOARG;

	/* OP_BLOCK	label{arg}, block-name{symbol}
	     ...
	   OP_EXIT
	   label:

	   Executes the enclosed code in a named block.  LABEL points
	   to the first instruction after OP_EXIT.
	*/
	case OP_BLOCK:		string = "BLOCK\t";
				goto JEQL;

	/* OP_CALL	n{arg}
		Calls the function in VALUES(0) with N arguments which
		have been deposited in the stack. The output values
		are left in VALUES(...)
	*/
	case OP_CALL:		string = "CALL\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_CALLG	n{arg}, name{arg}
		Calls the function NAME with N arguments which have been
		deposited in the stack. The output values are left in VALUES.
	*/
	case OP_CALLG:		string = "CALLG\t";
				n = GET_OPARG(vector);
				o = GET_DATA(vector, bytecodes);
				goto OPARG_ARG;

	/* OP_FCALL	n{arg}
		Calls the function in the stack with N arguments which
		have been also deposited in the stack. The output values
		are left in VALUES(...)
	*/
	case OP_STEPCALL:
	case OP_FCALL:		string = "FCALL\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_PCALL	n{arg}
		Calls the function in VALUES(0) with N arguments which
		have been deposited in the stack. The first output value
		is pushed on the stack.
	*/
	case OP_PCALL:		string = "PCALL\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_PCALLG	n{arg}, name{arg}
		Calls the function NAME with N arguments which have been
		deposited in the stack. The first output value is pushed on
		the stack.
	*/
	case OP_PCALLG:		string = "PCALLG\t";
				n = GET_OPARG(vector);
				o = GET_DATA(vector, bytecodes);
				goto OPARG_ARG;

	/* OP_PFCALL	n{arg}
		Calls the function in the stack with N arguments which
		have been deposited in the stack. The first output value
		is pushed on the stack.
	*/
	case OP_PFCALL:		string = "PFCALL\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_MCALL
		Similar to FCALL, but gets the number of arguments from
		the stack (They all have been deposited by OP_PUSHVALUES)
	*/
	case OP_MCALL:		string = "MCALL";
				goto NOARG;

	/* OP_CATCH	label{arg}
	   ...
	   OP_EXIT_FRAME
	   label:

	   Sets a catch point using the tag in VALUES(0). LABEL points to the
	   first instruction after the end (OP_EXIT) of the block
	*/
	case OP_CATCH:		string = "CATCH\t";
				goto JMP;
	/* OP_EXIT
		Marks the end of a high level construct (DOLIST, DOTIMES...)
	*/
	case OP_EXIT:		print_noarg("EXIT");
				return vector;
	/* OP_EXIT_FRAME
		Marks the end of a high level construct (BLOCK, CATCH...)
	*/
	case OP_EXIT_FRAME:	string = "EXIT\tFRAME";
				goto NOARG;
	/* OP_EXIT_TAGBODY
		Marks the end of a high level construct (TAGBODY)
	*/
	case OP_EXIT_TAGBODY:	print_noarg("EXIT\tTAGBODY");
				return vector;

	case OP_FLET:		vector = disassemble_flet(bytecodes, vector);
				break;
	case OP_LABELS:		vector = disassemble_labels(bytecodes, vector);
				break;

	/* OP_LFUNCTION	name{symbol}
		Extracts the function associated to a symbol. The function
		may be defined in the global environment or in the local
		environment. This last value takes precedence.
	*/
	case OP_LFUNCTION:	string = "LOCFUNC\t";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_FUNCTION	name{symbol}
		Extracts the function associated to a symbol. The function
		may be defined in the global environment or in the local
		environment. This last value takes precedence.
	*/
	case OP_FUNCTION:	string = "SYMFUNC\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_CLOSE	name{arg}
		Extracts the function associated to a symbol. The function
		may be defined in the global environment or in the local
		environment. This last value takes precedence.
	*/
	case OP_CLOSE:		string = "CLOSE\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	/* OP_GO	n{arg}
	   OP_QUOTE	tag-name{symbol}
		Jumps to the tag which is defined at the n-th position in
		the lexical environment. TAG-NAME is kept for debugging
		purposes.
	*/
	case OP_GO:		string = "GO\t";
				n = GET_OPARG(vector);
				o = GET_DATA(vector, bytecodes);
				goto OPARG_ARG;

	/* OP_RETURN	n{arg}
		Returns from the block whose record in the lexical environment
		occuppies the n-th position.
	*/
	case OP_RETURN:		string = "RETFROM";
				n = GET_OPARG(vector);
				goto OPARG;

	/* OP_THROW
		Jumps to an enclosing CATCH form whose tag matches the one
		of the THROW. The tag is taken from the stack, while the
		output values are left in VALUES(...).
	*/
	case OP_THROW:		string = "THROW";
				goto NOARG;

	/* OP_JMP	label{arg}
	   OP_JNIL	label{arg}
	   OP_JT	label{arg}
	   OP_JEQ	label{arg}, value{object}
	   OP_JNEQ	label{arg}, value{object}
		Direct or conditional jumps. The conditional jumps are made
		comparing with the value of VALUES(0).
	*/
	case OP_JMP:		string = "JMP\t";
				goto JMP;
	case OP_JNIL:		string = "JNIL\t";
				goto JMP;
	case OP_JT:		string = "JT\t";
	JMP: {			cl_oparg jmp = GET_OPARG(vector);
				n = vector + jmp - OPARG_SIZE - base;
				goto OPARG;
	}
	case OP_JEQL:		string = "JEQL\t";
				goto JEQL;
	case OP_JNEQL:		string = "JNEQL\t";
	JEQL: {			cl_oparg jmp;
				o = GET_DATA(vector, bytecodes);
				jmp = GET_OPARG(vector);
				n = vector + jmp - OPARG_SIZE - base;
				goto OPARG_ARG;
	}
	case OP_NOT:		string = "NOT";
				goto NOARG;

	/* OP_UNBIND	n{arg}
		Undo "n" bindings of lexical variables.
	*/
	case OP_UNBIND:		string = "UNBIND\t";
				n = GET_OPARG(vector);
				goto OPARG;
	/* OP_UNBINDS	n{arg}
		Undo "n" bindings of special variables.
	*/
	case OP_UNBINDS:	string = "UNBINDS\t";
				n = GET_OPARG(vector);
				goto OPARG;
	/* OP_BIND	name{symbol}
	   OP_PBIND	name{symbol}
	   OP_BINDS	name{symbol}
	   OP_PBINDS	name{symbol}
		Binds a lexical or special variable to the either the
		value of VALUES(0), to the first value of the stack, or
		to the n-th value of VALUES(...).
	*/
	case OP_BIND:		string = "BIND\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_PBIND:		string = "PBIND\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_VBIND:		string = "VBIND\t";
				n = GET_OPARG(vector);
				o = GET_DATA(vector, bytecodes);
				goto OPARG_ARG;
	case OP_BINDS:		string = "BINDS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_PBINDS:		string = "PBINDS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_VBINDS:		string = "VBINDS\t";
				n = GET_OPARG(vector);
				o = GET_DATA(vector, bytecodes);
				goto OPARG_ARG;
	/* OP_SETQ	n{arg}
	   OP_PSETQ	n{arg}
	   OP_SETQS	var-name{symbol}
	   OP_PSETQS	var-name{symbol}
		Sets either the n-th local or a special variable VAR-NAME,
		to either the value in VALUES(0) (OP_SETQ[S]) or to the 
		first value on the stack (OP_PSETQ[S]).
	*/
	case OP_SETQ:		string = "SETQ\t";
				n = GET_OPARG(vector);
				goto OPARG;
	case OP_PSETQ:		string = "PSETQ\t";
				n = GET_OPARG(vector);
				goto OPARG;
	case OP_SETQS:		string = "SETQS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_PSETQS:		string = "PSETQS\t";
				o = GET_DATA(vector, bytecodes);
				goto ARG;

	case OP_MSETQ:		vector = disassemble_msetq(bytecodes, vector);
				break;
	case OP_PROGV:		vector = disassemble_progv(bytecodes, vector);
				break;

	/* OP_VALUES	n{arg}
		Pop N values from the stack and store them in VALUES(...)
	*/
	case OP_VALUES:		string = "VALUES\t";
				n = GET_OPARG(vector);
				goto OPARG;
	/* OP_NTHVAL
		Set VALUES(0) to the N-th value of the VALUES(...) list.
		The index N-th is extracted from the top of the stack.
	*/
	case OP_NTHVAL:		string = "NTHVAL\t";
				goto NOARG;
	case OP_DOLIST:		vector = disassemble_dolist(bytecodes, vector);
				break;
	case OP_DOTIMES:	vector = disassemble_dotimes(bytecodes, vector);
				break;
	/* OP_DO	label
	     ...	; code executed within a NIL block
	   OP_EXIT_FRAME
	   label:

	   High level construct for the DO and BLOCK forms.
	*/
	case OP_DO:		string = "DO\t";
				goto JMP;
	case OP_TAGBODY:	vector = disassemble_tagbody(bytecodes, vector);
				break;
	/* OP_PROTECT	label
	     ...	; code to be protected and whose value is output
	   OP_PROTECT_NORMAL
	   label:
	     ...	; code executed at exit
	   OP_PROTECT_EXIT

	  High level construct for UNWIND-PROTECT. The first piece of code is
	  executed and its output value is saved. Then the second piece of code
	  is executed and the output values restored. The second piece of code
	  is always executed, even if a THROW, RETURN or GO happen within the
	  first piece of code.
	*/
	case OP_PROTECT:	string = "PROTECT\t";
				goto JMP;
	case OP_PROTECT_NORMAL:	string = "PROTECT\tNORMAL";
				goto NOARG;
	case OP_PROTECT_EXIT:	string = "PROTECT\tEXIT";
				goto NOARG;
	case OP_NIL:		string = "QUOTE\tNIL";
				goto NOARG;
	case OP_PUSHNIL:	string = "PUSH\t'NIL";
		    		goto NOARG;
	case OP_STEPIN:		string = "STEP\tIN,";
				o = GET_DATA(vector, bytecodes);
				goto ARG;
	case OP_STEPOUT:	string = "STEP\tOUT";
				goto NOARG;
	default:
		FEerror("Unknown code ~S", 1, MAKE_FIXNUM(*(vector-1)));
		return vector;
	NOARG:			print_noarg(string);
				break;
	ARG:			print_noarg(string);
				@prin1(1, o);
				break;
	OPARG:			print_oparg(string, n);
				break;
	OPARG_ARG:		print_oparg_arg(string, n, o);
				break;
	}
	goto BEGIN;
}

cl_object
si_bc_disassemble(cl_object v)
{
	if (type_of(v) == t_bytecodes) {
		disassemble_lambda(v);
		@(return v)
	}
	@(return Cnil)
}

cl_object
si_bc_split(cl_object b)
{
	cl_object vector;
	cl_object data;

	if (type_of(b) != t_bytecodes)
		@(return Cnil Cnil)
	vector = cl_alloc_simple_vector(b->bytecodes.code_size, aet_b8);
	vector->vector.self.b8 = b->bytecodes.code;
	data = cl_alloc_simple_vector(b->bytecodes.data_size, aet_object);
	data->vector.self.t = b->bytecodes.data;
	@(return b->bytecodes.lex vector data)
}