As a first step towards making roff_res() callable from mandoc_getarg(),

move the function mandoc_getarg() from mandoc.c to roff.c.  It was
misplaced in mandoc.c in the first place; that file is intended for
utilities needed both by parsers and by formatters, while reading
macro arguments in copy mode is purely a task of the roff(7) parser.
Needed as a preliminary for an upcoming bugfix.
No code change.

1 files changed, 97 insertions, 0 deletions

diff --git a/roff.c b/roff.c
index 02dae757..be4a0a1c 100644
--- a/roff.c
+++ b/roff.c
@@ -1547,6 +1547,103 @@ roff_res(struct roff *r, struct buf *buf, int ln, int pos)
 }
 
 /*
+ * Parse a quoted or unquoted roff-style request or macro argument.
+ * Return a pointer to the parsed argument, which is either the original
+ * pointer or advanced by one byte in case the argument is quoted.
+ * NUL-terminate the argument in place.
+ * Collapse pairs of quotes inside quoted arguments.
+ * Advance the argument pointer to the next argument,
+ * or to the NUL byte terminating the argument line.
+ */
+char *
+mandoc_getarg(char **cpp, int ln, int *pos)
+{
+	char	 *start, *cp;
+	int	  quoted, pairs, white;
+
+	/* Quoting can only start with a new word. */
+	start = *cpp;
+	quoted = 0;
+	if ('"' == *start) {
+		quoted = 1;
+		start++;
+	}
+
+	pairs = 0;
+	white = 0;
+	for (cp = start; '\0' != *cp; cp++) {
+
+		/*
+		 * Move the following text left
+		 * after quoted quotes and after "\\" and "\t".
+		 */
+		if (pairs)
+			cp[-pairs] = cp[0];
+
+		if ('\\' == cp[0]) {
+			/*
+			 * In copy mode, translate double to single
+			 * backslashes and backslash-t to literal tabs.
+			 */
+			switch (cp[1]) {
+			case 'a':
+			case 't':
+				cp[0] = '\t';
+				/* FALLTHROUGH */
+			case '\\':
+				pairs++;
+				cp++;
+				break;
+			case ' ':
+				/* Skip escaped blanks. */
+				if (0 == quoted)
+					cp++;
+				break;
+			default:
+				break;
+			}
+		} else if (0 == quoted) {
+			if (' ' == cp[0]) {
+				/* Unescaped blanks end unquoted args. */
+				white = 1;
+				break;
+			}
+		} else if ('"' == cp[0]) {
+			if ('"' == cp[1]) {
+				/* Quoted quotes collapse. */
+				pairs++;
+				cp++;
+			} else {
+				/* Unquoted quotes end quoted args. */
+				quoted = 2;
+				break;
+			}
+		}
+	}
+
+	/* Quoted argument without a closing quote. */
+	if (1 == quoted)
+		mandoc_msg(MANDOCERR_ARG_QUOTE, ln, *pos, NULL);
+
+	/* NUL-terminate this argument and move to the next one. */
+	if (pairs)
+		cp[-pairs] = '\0';
+	if ('\0' != *cp) {
+		*cp++ = '\0';
+		while (' ' == *cp)
+			cp++;
+	}
+	*pos += (int)(cp - start) + (quoted ? 1 : 0);
+	*cpp = cp;
+
+	if ('\0' == *cp && (white || ' ' == cp[-1]))
+		mandoc_msg(MANDOCERR_SPACE_EOL, ln, *pos, NULL);
+
+	return start;
+}
+
+
+/*
  * Process text streams.
  */
 static int