1 files changed, 6 insertions, 0 deletions
diff --git a/src/rt/rust_internal.h b/src/rt/rust_internal.h
index 61716703..42b61801 100644
--- a/src/rt/rust_internal.h
+++ b/src/rt/rust_internal.h
@@ -88,6 +88,10 @@ static size_t const TIME_SLICE_IN_MS = 10;
 
 static intptr_t const CONST_REFCOUNT = 0x7badface;
 
+// ABI tags for rust_start, rust_task::start and friends.
+static uintptr_t const ABI_X86_RUSTBOOT_CDECL = 1;
+static uintptr_t const ABI_X86_RUSTC_FASTCALL = 2;
+
 // This accounts for logging buffers.
 
 static size_t const BUF_BYTES = 2048;
@@ -241,6 +245,8 @@ public:
     size_t n_c_syms;
     size_t n_libs;
 
+    uintptr_t abi_tag;
+
     // Crates are immutable, constructed by the compiler.
 
     uintptr_t get_image_base() const;