Handle integer-extending for C ABI

We need to supply sext/zext attributes to LLVM to ensure that arguments
are extended to the appropriate width in the correct way.

Most platforms extend integers less than 32 bits, though not all.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/rt/rust_test_helpers.c b/src/rt/rust_test_helpers.c
index 00bfa63e6fe..d2ebdcca80c 100644
--- a/src/rt/rust_test_helpers.c
+++ b/src/rt/rust_test_helpers.c
@@ -243,3 +243,7 @@ double rust_interesting_average(uint64_t n, ...) {
     va_end(pairs);
     return sum / n;
 }
+
+int32_t rust_int8_to_int32(int8_t x) {
+    return (int32_t)x;
+}