1 files changed, 125 insertions, 0 deletions

diff --git a/lib/printbuf.c b/lib/printbuf.c
index 8c70128e319c..a7f80f63ca81 100644
--- a/lib/printbuf.c
+++ b/lib/printbuf.c
@@ -12,6 +12,11 @@
 #include <linux/slab.h>
 #include <linux/printbuf.h>
 
+static inline size_t printbuf_linelen(struct printbuf *buf)
+{
+	return buf->pos - buf->last_newline;
+}
+
 int printbuf_make_room(struct printbuf *out, unsigned extra)
 {
 	unsigned new_size;
@@ -69,3 +74,123 @@ void printbuf_exit(struct printbuf *buf)
 	}
 }
 EXPORT_SYMBOL(printbuf_exit);
+
+void prt_newline(struct printbuf *buf)
+{
+	unsigned i;
+
+	printbuf_make_room(buf, 1 + buf->indent);
+
+	__prt_char(buf, '\n');
+
+	buf->last_newline	= buf->pos;
+
+	for (i = 0; i < buf->indent; i++)
+		__prt_char(buf, ' ');
+
+	printbuf_nul_terminate(buf);
+
+	buf->last_field		= buf->pos;
+	buf->tabstop = 0;
+}
+EXPORT_SYMBOL(prt_newline);
+
+/**
+ * printbuf_indent_add - add to the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to add to the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces more spaces.
+ */
+void printbuf_indent_add(struct printbuf *buf, unsigned spaces)
+{
+	if (WARN_ON_ONCE(buf->indent + spaces < buf->indent))
+		spaces = 0;
+
+	buf->indent += spaces;
+	while (spaces--)
+		prt_char(buf, ' ');
+}
+EXPORT_SYMBOL(printbuf_indent_add);
+
+/**
+ * printbuf_indent_sub - subtract from the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to subtract from the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces less spaces.
+ */
+void printbuf_indent_sub(struct printbuf *buf, unsigned spaces)
+{
+	if (WARN_ON_ONCE(spaces > buf->indent))
+		spaces = buf->indent;
+
+	if (buf->last_newline + buf->indent == buf->pos) {
+		buf->pos -= spaces;
+		printbuf_nul_terminate(buf);
+	}
+	buf->indent -= spaces;
+}
+EXPORT_SYMBOL(printbuf_indent_sub);
+
+/**
+ * prt_tab - Advance printbuf to the next tabstop
+ *
+ * @buf: printbuf to control
+ *
+ * Advance output to the next tabstop by printing spaces.
+ */
+void prt_tab(struct printbuf *out)
+{
+	int spaces = max_t(int, 0, out->tabstops[out->tabstop] - printbuf_linelen(out));
+
+	BUG_ON(out->tabstop > ARRAY_SIZE(out->tabstops));
+
+	prt_chars(out, ' ', spaces);
+
+	out->last_field = out->pos;
+	out->tabstop++;
+}
+EXPORT_SYMBOL(prt_tab);
+
+/**
+ * prt_tab_rjust - Advance printbuf to the next tabstop, right justifying
+ * previous output
+ *
+ * @buf: printbuf to control
+ *
+ * Advance output to the next tabstop by inserting spaces immediately after the
+ * previous tabstop, right justifying previously outputted text.
+ */
+void prt_tab_rjust(struct printbuf *buf)
+{
+	BUG_ON(buf->tabstop > ARRAY_SIZE(buf->tabstops));
+
+	if (printbuf_linelen(buf) < buf->tabstops[buf->tabstop]) {
+		unsigned move = buf->pos - buf->last_field;
+		unsigned shift = buf->tabstops[buf->tabstop] -
+			printbuf_linelen(buf);
+
+		printbuf_make_room(buf, shift);
+
+		if (buf->last_field + shift < buf->size)
+			memmove(buf->buf + buf->last_field + shift,
+				buf->buf + buf->last_field,
+				min(move, buf->size - 1 - buf->last_field - shift));
+
+		if (buf->last_field < buf->size)
+			memset(buf->buf + buf->last_field, ' ',
+			       min(shift, buf->size - buf->last_field));
+
+		buf->pos += shift;
+		printbuf_nul_terminate(buf);
+	}
+
+	buf->last_field = buf->pos;
+	buf->tabstop++;
+}
+EXPORT_SYMBOL(prt_tab_rjust);