/*
 * Copyright (c) 2007 The Akuma Project
 * 
 * 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.
 *
 * $Id: output.c 130 2007-05-29 12:54:04Z asmodai $
 */
/*
    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright
    owned by the United Kingdom Secretary of State for Defence
    acting through the Defence Evaluation and Research Agency
    (DERA).  It is made available to Recipients with a
    royalty-free licence for its use, reproduction, transfer
    to other parties and amendment for any purpose not excluding
    product development provided that any such use et cetera
    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is
        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to
        show both the nature of and the organisation responsible
        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another
        party shall be deemed to be that party's acceptance of
        these conditions;

        (4) DERA gives no warranty or assurance as to its
        quality or suitability for any purpose and DERA accepts
        no liability whatsoever in relation to any use to which
        it may be put.
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "char.h"
#include "error.h"
#include "lex.h"
#include "output.h"


/*
    OUTPUT FILE

    This variable gives the main output file.  out is used within this file
    as a shorthand for lex_output.
*/

FILE *lex_output;
#define out lex_output


/*
    OUTPUT INDENTATION

    This routine outputs an indentation of d.
*/

static void
output_indent(int d)
{
	int n = 4 * d;
	for (; n >= 8; n -= 8) {
		fputc('\t', out);
	}
	for (; n; n--) {
		fputc(' ', out);
	}
	return;
}


/*
    FIND A CHARACTER LITERAL

    This routine finds the character literal corresponding to c.
*/

static char *
char_lit(letter c)
{
	static char buff[10];
	switch (c) {
	case '\n': return("'\\n'");
	case '\t': return("'\\t'");
	case '\v': return("'\\v'");
	case '\f': return("'\\f'");
	case '\\': return("'\\\\'");
	case '\'': return("'\\''");
	}
	if (c == EOF_LETTER) {
		return ("LEX_EOF");
	}
	if (c > 127) {
		return ("'?'");
	}
	sprintf(buff, "'%c'", (char)c);
	return (buff);
}


/*
    OUTPUT OPTIONS

    The flag in_pre_pass is used to indicate the preliminary pass to
    output_pass.  read_name gives the name of the character reading
    function used in the output routines.
*/

static int in_pre_pass = 0;
static char *read_name = "read_char";


/*
    OUTPUT PASS INFORMATION

    This routine outputs code for the lexical pass indicated by p.  n
    gives the depth of recursion and d gives the indentation.
*/

static int
output_pass(character *p, int n, int d)
{
	character *q;
	int cases = 0;
	int classes = 0;
	char *ret = NULL;
	char *args = NULL;
	char *cond = NULL;

	/* First pass */
	for (q = p->next; q != NULL; q = q->opt) {
		letter c = q->ch;
		if (c == LAST_LETTER) {
			ret = q->defn;
			args = q->args;
			cond = q->cond;
		} else if (c <= SIMPLE_LETTER) {
			cases++;
		} else {
			classes++;
		}
	}

	/* Deal with cases */
	if (cases || classes) {
		int w1 = (n == 0 && !in_pre_pass);
		int w2 = (n == 0 && in_pre_pass);
		output_indent(d);
		fprintf(out, "int c%d = %s()", n, read_name);
		if (classes || w1) {
			fprintf(out, ", t%d", n);
		}
		fputs(";\n", out);
		if (w1) {
			output_indent(d);
			fputs("t0 = lookup_char(c0);\n", out);
			output_indent(d);
			fputs("if (is_white(t0)) goto start;\n", out);
		}
		if (w2) {
			output_indent(d);
			fputs("restart: {\n", out);
			d++;
		}

		if (cases > 4) {
			/* Small number of cases */
			output_indent(d);
			fprintf(out, "switch (c%d) {\n", n);
			for (q = p->next; q != NULL; q = q->opt) {
				letter c = q->ch;
				if (c != LAST_LETTER && c <= SIMPLE_LETTER) {
					output_indent(d + 1);
					fprintf(out, "case %s: {\n",
						char_lit(c));
					if (output_pass(q, n + 1, d + 2) == 0) {
						output_indent(d + 2);
						fputs("break;\n", out);
					}
					output_indent(d + 1);
					fputs("}\n", out);
				}
			}
			output_indent(d);
			fputs("}\n", out);
		} else {
			/* Large number of cases */
			int started = 0;
			for (q = p->next; q != NULL; q = q->opt) {
				letter c = q->ch;
				if (c != LAST_LETTER && c <= SIMPLE_LETTER) {
					output_indent(d);
					if (started) {
						fputs("} else ", out);
					}
					fprintf(out, "if (c%d == %s) {\n",
						n, char_lit(c));
					output_pass(q, n + 1, d + 1);
					started = 1;
				}
			}
			if (started) {
				output_indent(d);
				fputs("}\n", out);
			}
		}

		if (classes) {
			/* Complex cases */
			int started = 0;
			if (!w1) {
				output_indent(d);
				fprintf(out, "t%d = lookup_char(c%d);\n", n, n);
			}
			for (q = p->next; q != NULL; q = q->opt) {
				letter c = q->ch;
				if (c != LAST_LETTER && c > SIMPLE_LETTER) {
					char *gnm;
					if (c == WHITE_LETTER) {
						gnm = "white";
					} else {
						int g = (int)(c - GROUP_LETTER);
						gnm = groups[g].name;
					}
					output_indent(d);
					if (started) {
						fputs("} else ", out);
					}
					fprintf(out, "if (is_%s(t%d)) {\n",
						gnm, n);
					output_pass(q, n + 1, d + 1);
					started = 1;
				}
			}
			output_indent(d);
			fputs("}\n", out);
		}
		if (w2) {
			d--;
			output_indent(d);
			fputs("}\n", out);
		}
		if (n) {
			output_indent(d);
			fprintf(out, "unread_char(c%d);\n", n);
		}
	}

	/* Deal with return */
	if (ret) {
		if (in_pre_pass) {
			int m = *ret;
			if (m) {
				char *str;
				if (m == '\\') {
					str = char_lit(find_escape(ret[1]));
					m = ret[2];
				} else {
					str = char_lit((letter)m);
					m = ret[1];
				}
				if (m) {
					error(ERROR_SERIOUS,
					      "Bad mapping string, '%s'", ret);
				}
				if (cond) {
					output_indent(d);
					fprintf(out, "if (%s) {\n", cond);
					output_indent(d + 1);
					fprintf(out, "c0 = %s;\n", str);
					output_indent(d + 1);
					fputs("goto restart;\n", out);
					output_indent(d);
					fputs("}\n", out);
				} else {
					output_indent(d);
					fprintf(out, "c0 = %s;\n", str);
					output_indent(d);
					fputs("goto restart;\n", out);
				}
			} else {
				output_indent(d);
				if (cond) {
					fprintf(out, "if (%s) ", cond);
				}
				fputs("goto start;\n", out);
			}
		} else {
			output_indent(d);
			if (cond) {
				fprintf(out, "if (%s) ", cond);
			}
			fprintf(out, "return(%s", ret);
			if (args) {
				int i;
				fputs("(c0", out);
				for (i = 1; i < n; i++) {
					fprintf(out, ", c%d", i);
				}
				fputs(")", out);
			}
			fputs(");\n", out);
		}
	}
	return ((ret && (cond == NULL)) ? 1 : 0);
}


/*
    OUTPUT INITIAL COMMENT

    This routine outputs a comment stating that the file is automatically
    generated.
*/

static void
output_comment(void)
{
	if (first_comment) {
		/* Print copyright comment, if present */
		fprintf(out, "%s\n\n", first_comment);
	}
	fputs("/*\n *  AUTOMATICALLY GENERATED", out);
	fprintf(out, " BY %s VERSION %s", progname, progvers);
	fputs("\n */\n\n\n", out);
	return;
}


/*
    MAIN OUTPUT ROUTINE

    This routine is the entry point for the main output routine.
*/

void
output_all(void)
{
	int c, n;

	/* Initial comment */
	output_comment();

	/* Character look-up table */
	fputs("/* LOOKUP TABLE */\n\n", out);
	fprintf(out, "static unsigned %s lookup_tab[257] = {\n",
		(no_groups >= 8 ? "short" : "char"));
	for (c = 0; c <= 256; c++) {
		unsigned int m = 0;
		letter a = (c == 256 ? EOF_LETTER : (letter)c);
		if (in_group(white_space, a)) {
			m = 1;
		}
		for (n = 0; n < no_groups; n++) {
			if (in_group(groups[n].defn, a)) {
				m |= (unsigned int)(1 << (n + 1));
			}
		}
		if ((c % 8) == 0) {
			fputs("    ", out);
		}
		fprintf(out, "0x%04x", m);
		if (c != 256) {
			if ((c % 8) == 7) {
				fputs(",\n", out);
			} else {
				fputs(", ", out);
			}
		}
	}
	fputs("\n};\n\n", out);

	/* Macros for accessing table */
	fputs("#ifndef LEX_EOF\n", out);
	fputs("#define LEX_EOF\t\t256\n", out);
	fputs("#endif\n\n", out);
	fputs("#define lookup_char(C)\t", out);
	fputs("((int)lookup_tab[(C)])\n", out);
	fputs("#define is_white(T)\t((T) & 0x0001)\n", out);
	for (n = 0; n < no_groups; n++) {
		char *gnm = groups[n].name;
		unsigned int m = (unsigned int)(1 << (n + 1));
		fprintf(out, "#define is_%s(T)\t", gnm);
		/*if ((int)strlen(gnm) < 8)fputc('\t', out);*/
		fprintf(out, "((T) & 0x%04x)\n", m);
	}
	fputs("\n\n", out);

	/* Lexical pre-pass */
	if (pre_pass->next) {
		in_pre_pass = 1;
		fputs("/* PRE-PASS ANALYSER */\n\n", out);
		fputs("static int read_char_aux(void)\n", out);
		fputs("{\n", out);
		fputs("    start: {\n", out);
		output_pass(pre_pass, 0, 2);
		fputs("\treturn(c0);\n", out);
		fputs("    }\n", out);
		fputs("}\n\n\n", out);
		read_name = "read_char_aux";
	}

	/* Main pass */
	in_pre_pass = 0;
	fputs("/* MAIN PASS ANALYSER */\n\n", out);
	fputs("int\nread_token(void)\n", out);
	fputs("{\n", out);
	fputs("    start: {\n", out);
	output_pass(main_pass, 0, 2);
	fputs("\treturn(unknown_token(c0));\n", out);
	fputs("    }\n", out);
	fputs("}\n", out);
	return;
}


/*
    OUTPUT CODE FOR A SINGLE KEYWORD

    This routine outputs code for the keyword p.
*/

static void
output_word(keyword *p)
{
	fprintf(out, "MAKE_KEYWORD(\"%s\", %s", p->name, p->defn);
	if (p->args) {
		fputs("()", out);
	}
	fputs(");\n", out);
	p->done = 1;
	return;
}


/*
    KEYWORD OUTPUT ROUTINE

    This routine outputs code to generate all keywords.
*/

void
output_keyword(void)
{
	keyword *p, *q;
	output_comment();
	fputs("/* KEYWORDS */\n\n", out);
	for (p = keywords; p != NULL; p = p->next) {
		if (p->done == 0) {
			char *cond = p->cond;
			if (cond) {
				fprintf(out, "if (%s) {\n    ", cond);
				output_word(p);
				for (q = p->next; q != NULL; q = q->next) {
					if (q->cond &&
					    strcmp(q->cond, cond) == 0) {
						fputs("    ", out);
						output_word(q);
					}
				}
				fputs("}\n", out);
			} else {
				output_word(p);
				for (q = p->next; q != NULL; q = q->next) {
					if (q->cond == NULL) {
						output_word(q);
					}
				}
			}
		}
	}
	return;
}