Implement .previous (swap section back to the last section)

This enables:
	.data
	.asciz "foo"
	.previous
.. just like on current binutils

3 files changed, 32 insertions, 2 deletions

diff --git a/gnu/usr.bin/as/as.h b/gnu/usr.bin/as/as.h
index 6b81ac9..4a6893b 100644
--- a/gnu/usr.bin/as/as.h
+++ b/gnu/usr.bin/as/as.h
@@ -187,11 +187,11 @@ typedef enum _segT {
 
 typedef int subsegT;
 
-COMMON subsegT			now_subseg;
+COMMON subsegT			now_subseg, prev_subseg;
 /* What subseg we are accreting now? */
 
 
-COMMON segT			now_seg;
+COMMON segT			now_seg, prev_seg;
 /* Segment our instructions emit to. */
 /* Only OK values are SEG_TEXT or SEG_DATA. */
 
diff --git a/gnu/usr.bin/as/read.c b/gnu/usr.bin/as/read.c
index f25f363..1b64ee6 100644
--- a/gnu/usr.bin/as/read.c
+++ b/gnu/usr.bin/as/read.c
@@ -248,6 +248,7 @@ static const pseudo_typeS
 	{ "octa",	big_cons,	16	},
 	{ "org",	s_org,		0	},
 	{ "p2align",	s_align_ptwo,	0	},
+	{ "previous",	s_previous,	0	},
 #ifdef NO_LISTING
 	{ "psize",	s_ignore,	0       },   /* set paper size */
 #else
@@ -741,6 +742,9 @@ void
 {
 	register int temp;
 
+	prev_seg = now_seg;
+	prev_subseg = now_subseg;
+
 	temp = get_absolute_expression();
 	subseg_new (SEG_DATA, (subsegT)temp);
 
@@ -750,6 +754,27 @@ void
 	demand_empty_rest_of_line();
 }
 
+void
+    s_previous()
+{
+	segT oprev_seg = now_seg;
+	subsegT oprev_subseg = now_subseg;
+
+	oprev_seg = now_seg;
+	oprev_subseg = now_subseg;
+
+	subseg_new (prev_seg, prev_subseg);
+
+	prev_seg = oprev_seg;
+	prev_subseg = oprev_subseg;
+
+#ifdef OBJ_VMS
+	const_flag = 0;
+#endif /* not OBJ_VMS */
+	demand_empty_rest_of_line();
+}
+
+
 /* Handle the .appfile pseudo-op.  This is automatically generated by
    do_scrub_next_char when a preprocessor # line comment is seen with
    a file name.  This default definition may be overridden by the
@@ -1313,6 +1338,9 @@ void
 {
 	register int temp;
 
+	prev_seg = now_seg;
+	prev_subseg = now_subseg;
+
 	temp = get_absolute_expression();
 	subseg_new (SEG_TEXT, (subsegT)temp);
 	demand_empty_rest_of_line();
diff --git a/gnu/usr.bin/as/read.h b/gnu/usr.bin/as/read.h
index e396922..29d3dfc 100644
--- a/gnu/usr.bin/as/read.h
+++ b/gnu/usr.bin/as/read.h
@@ -96,6 +96,7 @@ void s_ignore(int arg);
 void s_include(int arg);
 void s_lcomm(int needs_align);
 void s_lsym(void);
+void s_previous(void);
 void s_org(void);
 void s_set(void);
 void s_size(void);
@@ -138,6 +139,7 @@ void s_ignore();
 void s_include();
 void s_lcomm();
 void s_lsym();
+void s_previous();
 void s_org();
 void s_set();
 void s_size();