2.11BSD/src/ucb/indent/lexi.c
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char sccsid[] = "@(#)lexi.c 5.4 (Berkeley) 9/10/85";
#endif not lint
/*-
*
* Copyright (C) 1976
* by the
* Board of Trustees
* of the
* University of Illinois
*
* All rights reserved
*
*
* NAME:
* lexi
*
* FUNCTION:
* This is the token scanner for indent
*
* ALGORITHM:
* 1) Strip off intervening blanks and/or tabs.
* 2) If it is an alphanumeric token, move it to the token buffer "token".
* Check if it is a special reserved word that indent will want to
* know about.
* 3) Non-alphanumeric tokens are handled with a big switch statement. A
* flag is kept to remember if the last token was a "unary delimiter",
* which forces a following operator to be unary as opposed to binary.
*
* PARAMETERS:
* None
*
* RETURNS:
* An integer code indicating the type of token scanned.
*
* GLOBALS:
* buf_ptr =
* had_eof
* ps.last_u_d = Set to true iff this token is a "unary delimiter"
*
* CALLS:
* fill_buffer
* printf (lib)
*
* CALLED BY:
* main
*
* NOTES:
* Start of comment is passed back so that the comment can be scanned by
* pr_comment.
*
* Strings and character literals are returned just like identifiers.
*
* HISTORY:
* initial coding November 1976 D A Willcox of CAC
* 1/7/77 D A Willcox of CAC Fix to provide proper handling
* of "int a -1;"
*
*/
/*
* Here we have the token scanner for indent. It scans off one token and
* puts it in the global variable "token". It returns a code, indicating
* the type of token scanned.
*/
#include "indent_globs.h";
#include "indent_codes.h";
#include "ctype.h"
#define alphanum 1
#define opchar 3
struct templ {
char *rwd;
int rwcode;
};
struct templ specials[100] =
{
"switch", 1,
"case", 2,
"break", 0,
"struct", 3,
"union", 3,
"enum", 3,
"default", 2,
"int", 4,
"char", 4,
"float", 4,
"double", 4,
"long", 4,
"short", 4,
"typdef", 4,
"unsigned", 4,
"register", 4,
"static", 4,
"global", 4,
"extern", 4,
"void", 4,
"goto", 0,
"return", 0,
"if", 5,
"while", 5,
"for", 5,
"else", 6,
"do", 6,
"sizeof", 7,
0, 0
};
char chartype[128] =
{ /* this is used to facilitate the decision
* of what type (alphanumeric, operator)
* each character is */
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 3, 0, 0, 0, 3, 3, 0,
0, 0, 3, 3, 0, 3, 3, 3,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 0, 0, 3, 3, 3, 3,
0, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 0, 0, 0, 3, 1,
0, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 0, 3, 0, 3, 0
};
int
lexi()
{
register char *tok; /* local pointer to next char in token */
int unary_delim; /* this is set to 1 if the current token
*
* forces a following operator to be unary */
static int last_code; /* the last token type returned */
static int l_struct; /* set to 1 if the last token was 'struct' */
int code; /* internal code to be returned */
char qchar; /* the delimiter character for a string */
tok = token; /* point to start of place to save token */
unary_delim = false;
ps.col_1 = ps.last_nl; /* tell world that this token started in
* column 1 iff the last thing scanned was
* nl */
ps.last_nl = false;
while (*buf_ptr == ' ' || *buf_ptr == '\t') { /* get rid of blanks */
ps.col_1 = false; /* leading blanks imply token is not in
* column 1 */
if (++buf_ptr >= buf_end)
fill_buffer();
}
/* Scan an alphanumeric token. Note that we must also handle
* stuff like "1.0e+03" and "7e-6". */
if (chartype[*buf_ptr & 0177] == alphanum) { /* we have a character
* or number */
register char *j; /* used for searching thru list of
* reserved words */
register struct templ *p;
register int c;
do { /* copy it over */
*tok++ = *buf_ptr++;
if (buf_ptr >= buf_end)
fill_buffer();
} while (chartype[c = *buf_ptr & 0177] == alphanum ||
isdigit(token[0]) && (c == '+' || c == '-') &&
(tok[-1] == 'e' || tok[-1] == 'E'));
*tok++ = '\0';
while (*buf_ptr == ' ' || *buf_ptr == '\t') { /* get rid of blanks */
if (++buf_ptr >= buf_end)
fill_buffer();
}
ps.its_a_keyword = false;
ps.sizeof_keyword = false;
if (l_struct) { /* if last token was 'struct', then this
* token should be treated as a
* declaration */
l_struct = false;
last_code = ident;
ps.last_u_d = true;
return (decl);
}
ps.last_u_d = false; /* Operator after indentifier is binary */
last_code = ident; /* Remember that this is the code we will
* return */
/*
* This loop will check if the token is a keyword.
*/
for (p = specials; (j = p->rwd) != 0; p++) {
tok = token; /* point at scanned token */
if (*j++ != *tok++ || *j++ != *tok++)
continue; /* This test depends on the fact that
* identifiers are always at least 1
* character long (ie. the first two bytes
* of the identifier are always
* meaningful) */
if (tok[-1] == 0)
break; /* If its a one-character identifier */
while (*tok++ == *j)
if (*j++ == 0)
goto found_keyword; /* I wish that C had a multi-level
* break... */
}
if (p->rwd) { /* we have a keyword */
found_keyword:
ps.its_a_keyword = true;
ps.last_u_d = true;
switch (p->rwcode) {
case 1: /* it is a switch */
return (swstmt);
case 2: /* a case or default */
return (casestmt);
case 3: /* a "struct" */
if (ps.p_l_follow)
break; /* inside parens: cast */
l_struct = true;
/*
* Next time around, we will want to know that we have
* had a 'struct'
*/
case 4: /* one of the declaration keywords */
if (ps.p_l_follow) {
ps.cast_mask |= 1 << ps.p_l_follow;
break; /* inside parens: cast */
}
last_code = decl;
return (decl);
case 5: /* if, while, for */
return (sp_paren);
case 6: /* do, else */
return (sp_nparen);
case 7:
ps.sizeof_keyword = true;
default: /* all others are treated like any other
* identifier */
return (ident);
} /* end of switch */
} /* end of if (found_it) */
if (*buf_ptr == '(' && ps.tos <= 1 && ps.ind_level == 0
&& (buf_ptr[1] != ')' || buf_ptr[2] != ';')) {
strncpy(ps.procname, token, sizeof ps.procname - 1);
ps.in_parameter_declaration = 1;
}
/*
* The following hack attempts to guess whether or not the current
* token is in fact a declaration keyword -- one that has been
* typedefd
*/
if (((*buf_ptr == '*' && buf_ptr[1] != '=') || isalpha(*buf_ptr))
&& !ps.p_l_follow
&& (ps.last_token == rparen || ps.last_token == semicolon ||
ps.last_token == decl ||
ps.last_token == lbrace || ps.last_token == rbrace)) {
ps.its_a_keyword = true;
ps.last_u_d = true;
last_code = decl;
return decl;
}
if (last_code == decl) /* if this is a declared variable, then
* following sign is unary */
ps.last_u_d = true; /* will make "int a -1" work */
last_code = ident;
return (ident); /* the ident is not in the list */
} /* end of procesing for alpanum character */
/* Scan a non-alphanumeric token */
*tok++ = *buf_ptr; /* if it is only a one-character token, it
* is moved here */
*tok = '\0';
if (++buf_ptr >= buf_end)
fill_buffer();
switch (*token) {
case '\n':
unary_delim = ps.last_u_d;
ps.last_nl = true; /* remember that we just had a newline */
code = (had_eof ? 0 : newline);
/*
* if data has been exausted, the newline is a dummy, and we
* should return code to stop
*/
break;
case '\'': /* start of quoted character */
case '"': /* start of string */
qchar = *token;
if (troff) {
tok[-1] = '`';
if (qchar == '"')
*tok++ = '`';
*tok++ = BACKSLASH;
*tok++ = 'f';
*tok++ = 'L';
}
do { /* copy the string */
while (1) { /* move one character or [/<char>]<char> */
if (*buf_ptr == '\n') {
printf("%d: Unterminated literal\n", line_no);
goto stop_lit;
}
*tok = *buf_ptr++;
if (buf_ptr >= buf_end)
fill_buffer();
if (had_eof || ((tok - token) > (bufsize - 2))) {
printf("Unterminated literal\n");
++tok;
goto stop_lit;
/* get outof literal copying loop */
}
if (*tok == BACKSLASH) { /* if escape, copy extra
* char */
if (*buf_ptr == '\n') /* check for escaped
* newline */
++line_no;
if (troff) {
*++tok = BACKSLASH;
if (*buf_ptr == BACKSLASH)
*++tok = BACKSLASH;
}
*++tok = *buf_ptr++;
++tok; /* we must increment this again because we
* copied two chars */
if (buf_ptr >= buf_end)
fill_buffer();
}
else
break; /* we copied one character */
} /* end of while (1) */
} while (*tok++ != qchar);
if (troff) {
tok[-1] = BACKSLASH;
*tok++ = 'f';
*tok++ = 'R';
*tok++ = '\'';
if (qchar == '"')
*tok++ = '\'';
}
stop_lit:
code = ident;
break;
case ('('):
case ('['):
unary_delim = true;
code = lparen;
break;
case (')'):
case (']'):
code = rparen;
break;
case '#':
unary_delim = ps.last_u_d;
code = preesc;
break;
case '?':
unary_delim = true;
code = question;
break;
case (':'):
code = colon;
unary_delim = true;
break;
case (';'):
unary_delim = true;
code = semicolon;
break;
case ('{'):
unary_delim = true;
/*
* if (ps.in_or_st) ps.block_init = 1;
*/
code = ps.block_init ? lparen : lbrace;
break;
case ('}'):
unary_delim = true;
code = ps.block_init ? rparen : rbrace;
break;
case 014: /* a form feed */
unary_delim = ps.last_u_d;
ps.last_nl = true; /* remember this so we can set 'ps.col_1'
* right */
code = form_feed;
break;
case (','):
unary_delim = true;
code = comma;
break;
case '.':
unary_delim = false;
code = period;
break;
case '-':
case '+': /* check for -, +, --, ++ */
code = (ps.last_u_d ? unary_op : binary_op);
unary_delim = true;
if (*buf_ptr == token[0]) {
/* check for doubled character */
*tok++ = *buf_ptr++;
/* buffer overflow will be checked at end of loop */
if (last_code == ident || last_code == rparen) {
code = (ps.last_u_d ? unary_op : postop);
/* check for following ++ or -- */
unary_delim = false;
}
}
else if (*buf_ptr == '=')
/* check for operator += */
*tok++ = *buf_ptr++;
else if (token[0] == '-' && *buf_ptr == '>') {
/* check for operator -> */
*tok++ = *buf_ptr++;
if (!pointer_as_binop) {
code = unary_op;
unary_delim = false;
ps.want_blank = false;
}
}
/* buffer overflow will be checked at end of switch */
break;
case '=':
if (ps.in_or_st)
ps.block_init = 1;
if (chartype[*buf_ptr] == opchar) { /* we have two char
* assignment */
tok[-1] = *buf_ptr++;
if ((tok[-1] == '<' || tok[-1] == '>') && tok[-1] == *buf_ptr)
*tok++ = *buf_ptr++;
*tok++ = '='; /* Flip =+ to += */
*tok = 0;
}
code = binary_op;
unary_delim = true;
break;
/* can drop thru!!! */
case '>':
case '<':
case '!': /* ops like <, <<, <=, !=, etc */
if (*buf_ptr == '>' || *buf_ptr == '<' || *buf_ptr == '=') {
*tok++ = *buf_ptr;
if (++buf_ptr >= buf_end)
fill_buffer();
}
if (*buf_ptr == '=')
*tok++ = *buf_ptr++;
code = (ps.last_u_d ? unary_op : binary_op);
unary_delim = true;
break;
default:
if (token[0] == '/' && *buf_ptr == '*') {
/* it is start of comment */
*tok++ = '*';
if (++buf_ptr >= buf_end)
fill_buffer();
code = comment;
unary_delim = ps.last_u_d;
break;
}
while (*(tok - 1) == *buf_ptr || *buf_ptr == '=') {
/* handle ||, &&, etc, and also things as in int *****i */
*tok++ = *buf_ptr;
if (++buf_ptr >= buf_end)
fill_buffer();
}
code = (ps.last_u_d ? unary_op : binary_op);
unary_delim = true;
} /* end of switch */
if (code != newline) {
l_struct = false;
last_code = code;
}
if (buf_ptr >= buf_end) /* check for input buffer empty */
fill_buffer();
ps.last_u_d = unary_delim;
*tok = '\0'; /* null terminate the token */
return (code);
};
/* Add the given keyword to the keyword table, using val as the keyword type
*/
addkey (key, val)
char *key;
{
register struct templ *p = specials;
while (p->rwd)
if (p->rwd[0] == key[0] && strcmp(p->rwd, key) == 0)
return;
else
p++;
if (p >= specials + sizeof specials / sizeof specials[0])
return; /* For now, table overflows are silently
ignored */
p->rwd = key;
p->rwcode = val;
p[1].rwd = 0;
p[1].rwcode = 0;
return;
}