#ifndef lint
static char sccsid[] = "@(#)rpc_scan.c 1.1 90/10/29 (C) 1987 SMI";
#endif

/*
 * rpc_scan.c, Scanner for the RPC protocol compiler 
 * Copyright (C) 1987, Sun Microsystems, Inc. 
 */
#include <stdio.h>
#include <ctype.h>
#include <strings.h>
#include <string.h>
#include "rpc_scan.h"
#include "rpc_util.h"

#define startcomment(where) (where[0] == '/' && where[1] == '*')
#define endcomment(where) (where[-1] == '*' && where[0] == '/')

static int pushed = 0;	/* is a token pushed */
static token lasttok;	/* last token, if pushed */

/*
 * scan expecting 1 given token 
 */
void
scan(expect, tokp)
	tok_kind expect;
	token *tokp;
{
	get_token(tokp);
	if (tokp->kind != expect) {
		expected1(expect);
	}
}

/*
 * scan expecting any of the 2 given tokens 
 */
void
scan2(expect1, expect2, tokp)
	tok_kind expect1;
	tok_kind expect2;
	token *tokp;
{
	get_token(tokp);
	if (tokp->kind != expect1 && tokp->kind != expect2) {
		expected2(expect1, expect2);
	}
}

/*
 * scan expecting any of the 3 given token 
 */
void
scan3(expect1, expect2, expect3, tokp)
	tok_kind expect1;
	tok_kind expect2;
	tok_kind expect3;
	token *tokp;
{
	get_token(tokp);
	if (tokp->kind != expect1 && tokp->kind != expect2
	    && tokp->kind != expect3) {
		expected3(expect1, expect2, expect3);
	}
}

/*
 * scan expecting a constant, possibly symbolic 
 */
void
scan_num(tokp)
	token *tokp;
{
	get_token(tokp);
	switch (tokp->kind) {
	case TOK_IDENT:
		break;
	default:
		error("constant or identifier expected");
	}
}

/*
 * Peek at the next token 
 */
void
peek(tokp)
	token *tokp;
{
	get_token(tokp);
	unget_token(tokp);
}

/*
 * Peek at the next token and scan it if it matches what you expect 
 */
int
peekscan(expect, tokp)
	tok_kind expect;
	token *tokp;
{
	peek(tokp);
	if (tokp->kind == expect) {
		get_token(tokp);
		return (1);
	}
	return (0);
}

/*
 * Get the next token, printing out any directive that are encountered. 
 */
void
get_token(tokp)
	token *tokp;
{
	int commenting;

	if (pushed) {
		pushed = 0;
		*tokp = lasttok;
		return;
	}
	commenting = 0;
	for (;;) {
		if (*CurrentContext->where == 0) {
			for (;;) {
				if (!fgets(CurrentContext->curline,
					   MAXLINESIZE, CurrentContext->fin)) {
					tokp->kind = TOK_EOF;
					*CurrentContext->where = 0;
					return;
				}
				CurrentContext->linenum++;
				if (commenting) {
					break;
				} else if (cppline(CurrentContext->curline)) {
					docppline(CurrentContext->curline,
						  &CurrentContext->linenum, 
						  &CurrentContext->infilename);
				} else if (directive(CurrentContext->curline)) {
					printdirective(CurrentContext->curline);
				} else {
					break;
				}
			}
			CurrentContext->where = CurrentContext->curline;
		} else if (isspace(*CurrentContext->where)) {
			while (isspace(*CurrentContext->where)) {
				CurrentContext->where++;	/* eat */
			}
		} else if (commenting) {
			for (CurrentContext->where++;
			     *CurrentContext->where;
			     CurrentContext->where++) {
				if (endcomment(CurrentContext->where)) {
					CurrentContext->where++;
					commenting--;
					break;
				}
			}
		} else if (startcomment(CurrentContext->where)) {
			CurrentContext->where += 2;
			commenting++;
		} else {
			break;
		}
	}

	/*
	 * 'where' is not whitespace, comment or directive Must be a token! 
	 */
	switch (*CurrentContext->where) {
	case ':':
		tokp->kind = TOK_COLON;
		CurrentContext->where++;
		break;
	case ';':
		tokp->kind = TOK_SEMICOLON;
		CurrentContext->where++;
		break;
	case ',':
		tokp->kind = TOK_COMMA;
		CurrentContext->where++;
		break;
	case '=':
		tokp->kind = TOK_EQUAL;
		CurrentContext->where++;
		break;
	case '*':
		tokp->kind = TOK_STAR;
		CurrentContext->where++;
		break;
	case '[':
		tokp->kind = TOK_LBRACKET;
		CurrentContext->where++;
		break;
	case ']':
		tokp->kind = TOK_RBRACKET;
		CurrentContext->where++;
		break;
	case '{':
		tokp->kind = TOK_LBRACE;
		CurrentContext->where++;
		break;
	case '}':
		tokp->kind = TOK_RBRACE;
		CurrentContext->where++;
		break;
	case '(':
		tokp->kind = TOK_LPAREN;
		CurrentContext->where++;
		break;
	case ')':
		tokp->kind = TOK_RPAREN;
		CurrentContext->where++;
		break;
	case '<':
		tokp->kind = TOK_LANGLE;
		CurrentContext->where++;
		break;
	case '>':
		tokp->kind = TOK_RANGLE;
		CurrentContext->where++;
		break;

	case '"':
		tokp->kind = TOK_STRCONST;
		findstrconst(&CurrentContext->where, &tokp->str);
		break;
	case '\'':
		tokp->kind = TOK_CHARCONST;
		findchrconst(&CurrentContext->where, &tokp->str);
		break;

	case '-':
	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
		tokp->kind = TOK_IDENT;
		findconst(&CurrentContext->where, &tokp->str);
		break;

	default:
		if (!(isalpha(*CurrentContext->where) ||
		      *CurrentContext->where == '_')) {
			char buf[100];
			char *p;

			s_print(buf, "illegal character in file: ");
			p = buf + strlen(buf);
			if (isprint(*CurrentContext->where)) {
				s_print(p, "%c", *CurrentContext->where);
			} else {
				s_print(p, "%d", *CurrentContext->where);
			}
			error(buf);
		}
		findkind(&CurrentContext->where, tokp);
		break;
	}
}

static
unget_token(tokp)
	token *tokp;
{
	lasttok = *tokp;
	pushed = 1;
}

static
findstrconst(str, val)
	char **str;
	char **val;
{
	char *p;
	int size;

	p = *str;
	do {
		*p++;
	} while (*p && *p != '"');
	if (*p == 0) {
		error("unterminated string constant");
	}
	p++;
	size = p - *str;
	*val = alloc(size + 1);
	(void) strncpy(*val, *str, size);
	(*val)[size] = 0;
	*str = p;
}

static
findchrconst(str, val)
	char **str;
	char **val;
{
	char *p;
	int size;

	p = *str;
	do {
		*p++;
	} while (*p && *p != '\'');
	if (*p == 0) {
		error("unterminated string constant");
	}
	p++;
	size = p - *str;
	if (size != 3) {
		error("empty char string");
	}
	*val = alloc(size + 1);
	(void) strncpy(*val, *str, size);
	(*val)[size] = 0;
	*str = p;
}

static
findconst(str, val)
	char **str;
	char **val;
{
	char *p;
	int size;

	p = *str;
	if (*p == '0' && *(p + 1) == 'x') {
		p++;
		do {
			p++;
		} while (isxdigit(*p));
	} else {
		do {
			p++;
		} while (isdigit(*p));
	}
	size = p - *str;
	*val = alloc(size + 1);
	(void) strncpy(*val, *str, size);
	(*val)[size] = 0;
	*str = p;
}

static token symbols[] = {
			  {TOK_CONST, "const"},
			  {TOK_UNION, "union"},
			  {TOK_SWITCH, "switch"},
			  {TOK_CASE, "case"},
			  {TOK_DEFAULT, "default"},
			  {TOK_STRUCT, "struct"},
			  {TOK_TYPEDEF, "typedef"},
			  {TOK_ENUM, "enum"},
			  {TOK_OPAQUE, "opaque"},
			  {TOK_BOOL, "bool"},
			  {TOK_VOID, "void"},
			  {TOK_CHAR, "char"},
			  {TOK_INT, "int"},
			  {TOK_UNSIGNED, "unsigned"},
			  {TOK_SHORT, "short"},
			  {TOK_LONG, "long"},
			  {TOK_FLOAT, "float"},
			  {TOK_DOUBLE, "double"},
			  {TOK_STRING, "string"},
			  {TOK_PROGRAM, "program"},
			  {TOK_VERSION, "version"},
			  {TOK_EOF, "??????"},
};

static
findkind(mark, tokp)
	char **mark;
	token *tokp;
{
	int len;
	token *s;
	char *str;
	int i;
	char *dest, *src;
	char nameBuf[128];

	str = *mark;
	for (s = symbols; s->kind != TOK_EOF; s++) {
		len = strlen(s->str);
		if (strncmp(str, s->str, len) == 0) {
			if (!isalnum(str[len]) && str[len] != '_') {
				tokp->kind = s->kind;
				tokp->str = s->str;
				*mark = str + len;
				return;
			}
		}
	}
	tokp->kind = TOK_IDENT;
	for (len = 0; isalnum(str[len]) || str[len] == '_'; len++);
	tokp->str = alloc(len + 1);
	for (i = 0, dest = tokp->str, src = str; i < len; i++) {
	    if (*src != '_')
		*dest++ = *src++;
	    else
		src++;
	}
	*dest = '\0';
	*mark = str + len;

	tokp->str = StripPrefix(svcName, tokp->str);
}

static
cppline(line)
	char *line;
{
	return (line == CurrentContext->curline && *line == '#');
}

static
directive(line)
	char *line;
{
	return (line == CurrentContext->curline && *line == '%');
}

/* Return ptr to just past non-white space. */
static char *SkipName(p)
     char *p;
{
    char *p1;
    for (p1 = p; ((*p1 != ' ') && (*p1 != '\t') && (*p1 != '\0')); p1++)
	;			/* NULL STAT */
    return (p1);
}

/* Return ptr to just past white space. */
static char *SkipWhiteSpace(p)
     char *p;
{
    char *p1;
    for (p1 = p; ((*p1 == ' ') || (*p1 == '\t')); p1++)
	;			/* NULL STAT */
    return (p1);
}

static
printdirective(line)
	char *line;
{
    char *line0 = line;
    char *p = malloc(strlen(line));
    char *p1, *p2;

    /*
     * We can handle directives of the following form:
     *   #define name value
     *      Don't emit anything since we can't be sure what's there.
     *   #ifndef ...
     *      Emit nothing.
     *   #endif ...
     *      Emit nothing.
     *   #define name
     *      Emit nothing.
     *   #include "foo.h"
     *      We can handle this only if there is a corresponding .x file
     *      that we can parse.  The meaning, in this case, is that we
     *      should import all the type decls from the corresponding Cedar
     *      interface file.
     */

    line++;			/* Skip over directive character. */
    line[strlen(line)-1] = '\0'; /* Get rid of trailing newline. */

    /* Determine what kind of directive we have and act accordingly. */
    if (strncmp(line, "#define", 7) == 0) {
	/* Emit nothing. */;
    }
    else if (strncmp(line, "#if", 3) == 0) {
	return;
    }
    else if (strncmp(line, "#endif", 6) == 0) {
	return;
    }
    else if (strncmp(line, "#include", 8) == 0) {
	line += 8;		/* Skip over #include */
	line = SkipWhiteSpace(line); /* Skip over white space. */
	line++;			/* Skip over " or < character. */
	strcpy(p, line);
	p1 = strrchr(p, '.');
	if (p1 == NULL) {
	    fprintf(stderr,
		    "ERROR: Unanticipated .X file directive encountered: %s\n",
		    line0);
	    fprintf(stderr, "  Unable to translate to Cedar.\n");
	    exit(-1);
	}
	*p1 = '\0';		/* Delimit end of include name. */
	ProcessImport(p);
    }
    /* else  Unknown directive line encountered.  All we can do is ignore it. */
}

static
docppline(line, lineno, fname)
	char *line;
	int *lineno;
	char **fname;
{
	char *file;
	int num;
	char *p;

	line++;
	while (isspace(*line)) {
		line++;
	}
	num = atoi(line);
	while (isdigit(*line)) {
		line++;
	}
	while (isspace(*line)) {
		line++;
	}
	if (*line != '"') {
		error("preprocessor error");
	}
	line++;
	p = file = alloc(strlen(line) + 1);
	while (*line && *line != '"') {
		*p++ = *line++;
	}
	if (*line == 0) {
		error("preprocessor error");
	}
	*p = 0;
	if (*file == 0) {
		*fname = NULL;
	} else {
		*fname = file;
	}
	*lineno = num - 1;
}