From 52bf506762f2d04ba37701af41b7b06c0d6dc7f9 Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Thu, 16 May 2019 12:57:50 -0700
Subject: stmt: continue in do-loop should evaluate controlling expression

---
 stmt.c           | 12 +++++++-----
 test/do-loop.c   |  9 +++++++++
 test/do-loop.qbe | 31 +++++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+), 5 deletions(-)
 create mode 100644 test/do-loop.c
 create mode 100644 test/do-loop.qbe

diff --git a/stmt.c b/stmt.c
index c53c969..8d45e3c 100644
--- a/stmt.c
+++ b/stmt.c
@@ -177,24 +177,26 @@ stmt(struct func *f, struct scope *s)
 		next();
 
 		label[0] = mkblock("do_body");
-		label[1] = mkblock("do_join");
+		label[1] = mkblock("do_cond");
+		label[2] = mkblock("do_join");
 
 		s = mkscope(s);
 		s = mkscope(s);
-		s->continuelabel = label[0];
-		s->breaklabel = label[1];
+		s->continuelabel = label[1];
+		s->breaklabel = label[2];
 		funclabel(f, label[0]);
 		stmt(f, s);
 		s = delscope(s);
 
 		expect(TWHILE, "after 'do' statement");
 		expect(TLPAREN, "after 'while'");
+		funclabel(f, label[1]);
 		e = expr(s);
 		expect(TRPAREN, "after expression");
 
 		v = funcexpr(f, e);
-		funcjnz(f, v, label[0], label[1]);  // XXX: compare to 0
-		funclabel(f, label[1]);
+		funcjnz(f, v, label[0], label[2]);  // XXX: compare to 0
+		funclabel(f, label[2]);
 		s = delscope(s);
 		expect(TSEMICOLON, "after 'do' statement");
 		break;
diff --git a/test/do-loop.c b/test/do-loop.c
new file mode 100644
index 0000000..2189a67
--- /dev/null
+++ b/test/do-loop.c
@@ -0,0 +1,9 @@
+int main(void) {
+	int x = 2, y = 0;
+	do {
+		if (x == 1)
+			continue;
+		++y;
+	} while (x--);
+	return y != 2;
+}
diff --git a/test/do-loop.qbe b/test/do-loop.qbe
new file mode 100644
index 0000000..c13b8fe
--- /dev/null
+++ b/test/do-loop.qbe
@@ -0,0 +1,31 @@
+export
+function w $main() {
+@start.1
+	%.1 =l alloc4 4
+	%.3 =l alloc4 4
+@body.2
+	%.2 =l add %.1, 0
+	storew 2, %.2
+	%.4 =l add %.3, 0
+	storew 0, %.4
+@do_body.3
+	%.5 =w loadsw %.1
+	%.6 =w ceqw %.5, 1
+	%.7 =w cnew %.6, 0
+	jnz %.7, @if_true.6, @if_false.7
+@if_true.6
+	jmp @do_cont.4
+@if_false.7
+	%.8 =w loadsw %.3
+	%.9 =w add %.8, 1
+	storew %.9, %.3
+@do_cont.4
+	%.10 =w loadsw %.1
+	%.11 =w sub %.10, 1
+	storew %.11, %.1
+	jnz %.10, @do_body.3, @do_join.5
+@do_join.5
+	%.12 =w loadsw %.3
+	%.13 =w cnew %.12, 2
+	ret %.13
+}
-- 
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