+static char sccsid[] = "@(#)lexi.c 4.1 (Berkeley) %G%";
+
+/*
+
+ 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
+ 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;"
+
+*/\f
+
+/* 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";
+
+
+
+#define alphanum 1
+#define opchar 3
+
+struct templ {
+ char *rwd;
+ int rwcode;
+};
+
+struct templ specials[] =
+{
+ "switch", 1,
+ "case", 2,
+ "struct", 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,
+ "if", 5,
+ "while", 5,
+ "for", 5,
+ "else", 6,
+ "do", 6,
+ "sizeof", 0,
+ 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 last_nl = true;
+ /* this is true if the last thing scanned was a newline */
+
+
+
+int lexi () {
+ register char *tok;
+ /* local pointer to next char in token */
+ register int i;
+ /* local loop counter */
+ register char *j;
+ /* used for searching thru list of reserved words */
+ 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 found_it;
+ 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;
+ col_1 = last_nl; /* tell world that this token started in column
+ 1 iff the last thing scanned was nl */
+ last_nl = false;
+
+ while (*buf_ptr == ' ' || *buf_ptr == '\t') {
+ /* get rid of blanks */
+ col_1 = false; /* leading blanks imply token is not in column 1
+ */
+ if (++buf_ptr >= buf_end)
+ fill_buffer ();
+ }
+
+/*----------------------------------------------------------*\
+| Scan an alphanumeric token
+\*----------------------------------------------------------*/
+
+ if (chartype[*buf_ptr & 0177] == alphanum) {
+ /* we have a character or number */
+ while (chartype[*buf_ptr & 0177] == alphanum) {
+ /* copy it over */
+ *tok++ = *buf_ptr++;
+ if (buf_ptr >= buf_end)
+ fill_buffer ();
+ }
+
+ *tok++ = '\0';
+
+ if (l_struct) { /* if last token was 'struct', then this token
+ should be treated as a declaration */
+ l_struct = false;
+ last_code = ident;
+ last_u_d = true;
+ return (decl);
+ }
+
+ last_u_d = false; /* operator after indentifier is binary */
+
+ for (i = 0; specials[i].rwd != 0; ++i) {
+ /* this loop will check if the token is a keyword. if so, a following
+ operator is unary */
+ last_code = ident; /* remember that this is the code we will return
+ */
+ j = specials[i].rwd;
+ /* point at ith reserved word */
+ tok = token; /* point at scanned toekn */
+ found_it = true; /* set to false if not found */
+ do {
+ if (*tok++ != *j) {
+ found_it = false;
+ break;
+ }
+ } while (*j++);
+
+ if (found_it) { /* we have a keyword */
+ last_u_d = true;
+ switch (specials[i].rwcode) {
+ case 1: /* it is a switch */
+ return (swstmt);
+ case 2: /* a case or default */
+ return (casestmt);
+
+ case 3: /* a "struct" */
+ 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(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);
+
+ default: /* all others are treated like any other
+ identifier */
+ return (ident);
+ } /* end of switch */
+ } /* end of if (found_it) */
+
+ }
+
+ if (last_code == decl) /* if this is a declared variable, then
+ following sign is unary */
+ 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 = last_u_d;
+ 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 */
+ qchar = '\''; /* remember final delimiter */
+ goto copy_lit; /* and go to common literal code */
+
+ case '"': /* start of string */
+ qchar = '"';
+
+ copy_lit:
+ do { /* copy the string */
+ while (1) { /* move one character or [/<char>]<char> */
+ if (*buf_ptr == '\n') {
+ /* check for unterminated literal */
+ printf ("%d: Unterminated literal\n", line_no);
+ goto stop_lit;
+ /* Don't copy any more */
+ }
+
+ *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 == '\\') {
+ /* if escape, copy extra char */
+ if (*buf_ptr == '\n')
+ /* check for escaped newline */
+ ++line_no;
+ *(++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);
+
+ stop_lit:
+ code = ident;
+ break;
+
+ case ('('):
+ case ('['):
+ unary_delim = true;
+ code = lparen;
+ break;
+
+ case (')'):
+ case (']'):
+ code = rparen;
+ break;
+
+ case '#':
+ unary_delim = 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;
+ code = lbrace;
+ break;
+
+ case ('}'):
+ unary_delim = true;
+ code = rbrace;
+ break;
+
+ case 014: /* a form feed */
+ unary_delim = last_u_d;
+ last_nl = true; /* remember this so we can set '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 = (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 = (last_u_d ? unary_op : postop);
+ /* check for following ++ or -- */
+ unary_delim = false;
+ }
+ }
+ else
+ if (*buf_ptr == '>' || *buf_ptr == '=')
+ /* check for operator -> or += */
+ *tok++ = *buf_ptr++;
+ /* buffer overflow will be checked at end of switch */
+
+ break;
+
+ case '=':
+ if (chartype[*buf_ptr] == opchar) {
+ /* we have two char assignment */
+ *tok++ = *buf_ptr;
+ /* move second character */
+ if (++buf_ptr >= buf_end)
+ fill_buffer ();
+ }
+
+ code = binary_op;
+ unary_delim = true;
+ if (token[1] != '<' && token[1] != '>')
+ /* check for possible 3 char operator */
+ 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 = (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 = 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 = (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 ();
+ last_u_d = unary_delim;
+ *tok = '\0'; /* null terminate the token */
+ return (code);
+};
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