frontend: accept zero size arrays and empty aggregates

GNU extension. Previously was overloading arraylength==0 to mean unsized
array, now they are distinct with the type flag TFUNKNOWN marking
unsized arrays & aggregates.

1 files changed, 28 insertions, 0 deletions

diff --git a/test/20-empty.c b/test/20-empty.c
new file mode 100644
index 0000000..2926185
--- /dev/null
+++ b/test/20-empty.c
@@ -0,0 +1,28 @@
+/* EXPECT:
+sizeof (struct empty) === 0
+sizeof bleh[1] === 0
+sizeof (struct flx0) == sizeof (int) === 1
+sizeof (a) === 0
+sizeof (aa) === 0
+*/
+
+void f(){}
+
+struct empty {};
+extern struct empty bleh[10];
+struct flx0 { int t; int m[0]; };
+
+int main() {
+   int a[] = {};
+   int aa[][0] = {};
+   struct empty empty = {};
+
+   extern int printf(const char *, ...);
+#define P(x) printf(#x" === %d\n", (int)x)
+   P(sizeof (struct empty));
+   P(sizeof bleh[1]);
+   P(sizeof (struct flx0) == sizeof (int));
+   P(sizeof (a));
+   P(sizeof (aa));
+}
+