Add `void` type and allow void* to be assigned to other ptr types

1 files changed, 6 insertions, 2 deletions

diff --git a/std/common.cup b/std/common.cup
index 24e24b7..68cf3a6 100644
--- a/std/common.cup
+++ b/std/common.cup
@@ -1,10 +1,14 @@
+
 const true = 1;
 const false = 0;
 
+// This should really be a constant, but we only allow integers...
+let null: void*; // Zero initialized by default.
+
 ///////////////////////////////////////////////////////////////////////////////
 // Syscalls
 
-fn write(fd: int, s: char*, n: int): int {
+fn write(fd: int, s: void*, n: int): int {
     return syscall3(SYS_write, fd, s, n);
 }
 
@@ -12,7 +16,7 @@ fn exit(status: int): int {
     return syscall1(SYS_exit, status);
 }
 
-fn read(fd: int, s: char*, n: int): int {
+fn read(fd: int, s: void*, n: int): int {
     return syscall3(SYS_read, fd, s, n);
 }