[cleanup] Simplify pr_comment().

Modify count_spaces() to take a third parameter "end" that will make the function return when the end is reached. This lets the caller pass a pointer to non nul-terminated sequence of characters. Rename count_spaces() to count_spaces_until() and reinstate count_spaces(), this time based on count_spaces_until().

Use count_spaces_until() to recalculate current column when going through a comment just before the fragment which decides if current line of the comment should be wrapped. This move simplifies this code by eliminating the need for keeping the column counter up to date every time e_com is advanced and also reduces spread of code that has to know how many columns a tab will produce.

indent.h

@@ -32,6 +32,7 @@ void	addkey(char *, int);
 int	compute_code_target(void);
 int	compute_label_target(void);
 int	count_spaces(int, char *);
+int	count_spaces_until(int, char *, char *);
 int	lexi(void);
 void	diag2(int, const char *);
 void	diag3(int, const char *, int);

io.c

@@ -507,18 +507,15 @@ pad_output(int current, int target)
  *
  */
 int
-count_spaces(int current, char *buffer)
+count_spaces_until(int cur, char *buffer, char *end)
 /*
  * this routine figures out where the character position will be after
  * printing the text in buffer starting at column "current"
  */
 {
     char *buf;		/* used to look thru buffer */
-    int cur;		/* current character counter */
 
-    cur = current;
-
-    for (buf = buffer; *buf != '\0'; ++buf) {
+    for (buf = buffer; *buf != '\0' && buf != end; ++buf) {
 	switch (*buf) {
 
 	case '\n':
@@ -542,6 +539,12 @@ count_spaces(int current, char *buffer)
     return (cur);
 }
 
+int
+count_spaces(int cur, char *buffer)
+{
+    return (count_spaces_until(cur, buffer, NULL));
+}
+
 void
 diag4(int level, const char *msg, int a, int b)
 {

pr_comment.c

@@ -45,6 +45,7 @@ __FBSDID("$FreeBSD: head/usr.bin/indent/pr_comment.c 116390 2003-06-15 09:28:17Z
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "indent_globs.h"
 #include "indent.h"
 /*
@@ -89,10 +90,6 @@ pr_comment(void)
     char       *t_ptr;		/* used for moving string */
     int         break_delim = comment_delimiter_on_blankline;
     int         l_just_saw_decl = ps.just_saw_decl;
-    /*
-     * int         ps.last_nl = 0;	 true iff the last significant thing
-     * weve seen is a newline
-     */
     int         one_liner = 1;	/* true iff this comment is a one-liner */
     adj_max_col = max_col;
     ps.just_saw_decl = 0;
@@ -167,21 +164,13 @@ pr_comment(void)
 
     *e_com = '\0';
     if (troff) {
-	now_col = 1;
 	adj_max_col = 80;
     }
-    else
-	now_col = count_spaces(ps.com_col, s_com);	/* figure what column we
-							 * would be in if we
-							 * printed the comment
-							 * now */
 
     /* Start to copy the comment */
 
     while (1) {			/* this loop will go until the comment is
 				 * copied */
-	if (*buf_ptr > 040 && *buf_ptr != '*')
-	    ps.last_nl = 0;
 	CHECK_SIZE_COM;
 	switch (*buf_ptr) {	/* this checks for various spcl cases */
 	case 014:		/* check for a form feed */
@@ -236,7 +225,6 @@ pr_comment(void)
 		    *e_com++ = ' ';
 		}
 		dump_line();
-		now_col = ps.com_col;
 	    }
 	    else {
 		ps.last_nl = 1;
@@ -250,7 +238,6 @@ pr_comment(void)
 		    last_bl = e_com;
 		    CHECK_SIZE_COM;
 		    *e_com++ = ' ';
-		    ++now_col;
 		}
 	    }
 	    ++line_no;		/* keep track of input line number */
@@ -285,7 +272,6 @@ pr_comment(void)
 		if (*(e_com - 1) != ' ' && !ps.box_com) {	/* insure blank before
 								 * end */
 		    *e_com++ = ' ';
-		    ++now_col;
 		}
 		if (break_delim == 1 && !one_liner && s_com[0] == '/'
 			&& s_com[1] == '*' && s_com[2] == ' ') {
@@ -299,11 +285,9 @@ pr_comment(void)
 		    e_com = t;
 		    s_com[0] = s_com[1] = s_com[2] = ' ';
 		}
-		if (break_delim == 2 && e_com > s_com + 3
-			 /* now_col > adj_max_col - 2 && !ps.box_com */ ) {
+		if (break_delim == 2 && e_com > s_com + 3) {
 		    *e_com = '\0';
 		    dump_line();
-		    now_col = ps.com_col;
 		}
 		CHECK_SIZE_COM;
 		*e_com++ = '*';
@@ -314,26 +298,20 @@ pr_comment(void)
 	    }
 	    else {		/* handle isolated '*' */
 		*e_com++ = '*';
-		++now_col;
 	    }
 	    break;
 	default:		/* we have a random char */
-	    *e_com = *buf_ptr++;
-	    if (buf_ptr >= buf_end)
-		fill_buffer();
-
-	    if (*e_com == '\t')	/* keep track of column */
-		now_col = ((now_col - 1) & tabmask) + tabsize + 1;
-	    else if (*e_com == '\b')	/* this is a backspace */
-		--now_col;
-	    else
-		++now_col;
-
-	    if (*e_com == ' ' || *e_com == '\t')
-		last_bl = e_com;
-	    /* remember we saw a blank */
-
-	    ++e_com;
+	    now_col = count_spaces_until(ps.com_col, s_com, e_com);
+	    do {
+		*e_com = *buf_ptr++;
+		if (buf_ptr >= buf_end)
+		    fill_buffer();
+		if (*e_com == ' ' || *e_com == '\t')
+		    last_bl = e_com;	/* remember we saw a blank */
+		++e_com;
+		now_col++;
+	    } while (!memchr("*\n\r\b\t", *buf_ptr, 6) && now_col <= adj_max_col);
+	    ps.last_nl = false;
 	    if (now_col > adj_max_col && !ps.box_com && e_com[-1] > ' ') {
 		/*
 		 * the comment is too long, it must be broken up
@@ -378,8 +356,6 @@ pr_comment(void)
 		    }
 		}
 		*e_com = '\0';
-		now_col = count_spaces(ps.com_col, s_com);	/* recompute current
-								 * position */
 	    }
 	    break;
 	}