decl: Implement GNU packed attribute

Implements: https://todo.sr.ht/~mcf/cproc/72

2 files changed, 26 insertions, 0 deletions

diff --git a/test/struct-packed.c b/test/struct-packed.c
new file mode 100644
index 0000000..d05bf91
--- /dev/null
+++ b/test/struct-packed.c
@@ -0,0 +1,9 @@
+struct [[gnu::packed]] {
+	char a;
+	long long b;
+	short c;
+} s = {1, 2, 3};
+
+int main(void) {
+	return s.a + s.b - s.c;
+}
diff --git a/test/struct-packed.qbe b/test/struct-packed.qbe
new file mode 100644
index 0000000..ee79301
--- /dev/null
+++ b/test/struct-packed.qbe
@@ -0,0 +1,17 @@
+export data $s = align 1 { b 1, l 2, h 3, }
+export
+function w $main() {
+@start.1
+@body.2
+	%.1 =l add $s, 0
+	%.2 =w loadsb %.1
+	%.3 =l extsb %.2
+	%.4 =l add $s, 1
+	%.5 =l loadl %.4
+	%.6 =l add %.3, %.5
+	%.7 =l add $s, 9
+	%.8 =w loadsh %.7
+	%.9 =l extsh %.8
+	%.10 =l sub %.6, %.9
+	ret %.10
+}