scc

commit 9ff031d254906ced8bc498a0db070afdc420f0ac
parent a2e934bedcd03584e32e7d0c2e66eb23eb6faa50
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sat, 28 Dec 2024 21:55:31 +0100

cc2: Write addstmt() based in insstmt()

This makes more sense and the previous implmentation was only a hack
to fast implementing insstmt().

Diffstat:
M
src/cmd/scc-cc/cc2/cc2.h
 | 
2
+-
M
src/cmd/scc-cc/cc2/node.c
 | 
43
++++++++++++++-----------------------------
M
src/cmd/scc-cc/cc2/parser.c
 | 
8
+++++---

3 files changed, 20 insertions(+), 33 deletions(-)
diff --git a/src/cmd/scc-cc/cc2/cc2.h b/src/cmd/scc-cc/cc2/cc2.h
@@ -277,7 +277,7 @@ extern Node *node(int op);
 extern Node *addstmt(Range *, Node *np, int flags);
 extern Node *delstmt(Range *);
 extern Node *nextstmt(Range *, int);
-extern Node *insstmt(Range *, Node *, Node *, int);
+extern Node *insstmt(Range *, Node *, Node *);
 extern void delrange(Range *);
 extern Range range(Node *, Node *);
 
diff --git a/src/cmd/scc-cc/cc2/node.c b/src/cmd/scc-cc/cc2/node.c
@@ -75,51 +75,36 @@ prforest(char *msg)
 }
 #endif
 
-/*
- * Insert a node after `at' and if mode is SETCUR
- * update the current statement if `at' was the
- * current statement
- */
 Node *
-insstmt(Range *rp, Node *np, Node *at, int mode)
-{
-	Node *save;
-
-	save = rp->cur;
-	rp->cur = at;
-	addstmt(rp, np, KEEPCUR);
-
-	if (mode == KEEPCUR)
-		rp->cur = save;
-	else
-		rp->cur = (save == at) ? np : save;
-
-	return np;
-}
-
-Node *
-addstmt(Range *rp, Node *np, int mode)
+insstmt(Range *rp, Node *np, Node *at)
 {
 	Node *next;
 
 	next = NULL;
-	if (rp->cur) {
-		next = rp->cur->next;
+	if (at) {
+		next = at->next;
 		if (next)
 			next->prev = np;
-		rp->cur->next = np;
+		at->next = np;
 	}
+
 	np->next = next;
-	np->prev = rp->cur;
+	np->prev = at;
 
 	if (!rp->begin)
 		rp->begin = np;
-	if (!rp->end || !np->next)
+	if (!rp->end || !next)
 		rp->end = np;
 
+	return np;
+}
+
+Node *
+addstmt(Range *rp, Node *np, int mode)
+{
+	insstmt(rp, np, rp->cur);
 	if (mode == SETCUR)
 		rp->cur = np;
-
 	return np;
 }
 
diff --git a/src/cmd/scc-cc/cc2/parser.c b/src/cmd/scc-cc/cc2/parser.c
@@ -346,15 +346,17 @@ oreturn(char *token, union tokenop u)
 static void
 waft(Node *np)
 {
-	Node *lastcase, *next;
+	Range *rp;
 	struct swtch *cur;
 
 	if (swp == swtbl)
 		error(EWTACKU);
 
 	cur = swp - 1;
-	lastcase = cur->last;
-	insstmt(fbody(), np, cur->last, SETCUR);
+	rp = fbody();
+	insstmt(rp, np, cur->last);
+	if (rp->cur == cur->last)
+		rp->cur = np;
 
 	cur->last = np;
 	cur->nr++;