Feat: prototype of self-hosted library

This is very much a work in progress. Still ruminating on the structure
of the library. It feels right but I want a more "social" presence -
namely the ability to link to a libc seemlessly. The solution is most
likely weak aliasing that musl uses - but musl itself weak aliases
global symbols, e.g malloc. We would have to define weak internal
symbols that musl defines as strong links but this knows too much about
the internals of musl...

8 files changed, 64 insertions, 0 deletions

diff --git a/sys/src/chdir.c b/sys/src/chdir.c
new file mode 100644
index 0000000..fd1385d
--- /dev/null
+++ b/sys/src/chdir.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+int
+sys·chdir(char *path)
+{
+    return syscall(·Chdir, path);
+}
diff --git a/sys/src/close.c b/sys/src/close.c
new file mode 100644
index 0000000..88b1e2b
--- /dev/null
+++ b/sys/src/close.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+int
+sys·close(int fd)
+{
+    return syscall(·Close, fd);
+}
diff --git a/sys/src/dup.c b/sys/src/dup.c
new file mode 100644
index 0000000..0943f52
--- /dev/null
+++ b/sys/src/dup.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+int
+sys·dup(int fd)
+{
+    return syscall(·Dup, fd);
+}
diff --git a/sys/src/internal.h b/sys/src/internal.h
new file mode 100644
index 0000000..2bb1422
--- /dev/null
+++ b/sys/src/internal.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <u.h>
+#include <internal/syscall.h>
+
+#define syscall1(n,a1)                   _syscall1(n,sysarg(a1))
+#define syscall2(n,a1,a2)                _syscall2(n,sysarg(a1),sysarg(a2))
+#define syscall3(n,a1,a2,a3)             _syscall3(n,sysarg(a1),sysarg(a2),sysarg(a3))
+#define syscall4(n,a1,a2,a3,a4)          _syscall4(n,sysarg(a1),sysarg(a2),sysarg(a3),sysarg(a4))
+#define syscall5(n,a1,a2,a3,a4,a5)       _syscall5(n,sysarg(a1),sysarg(a2),sysarg(a3),sysarg(a4),sysarg(a5))
+#define syscall6(n,a1,a2,a3,a4,a5,a6)    _syscall6(n,sysarg(a1),sysarg(a2),sysarg(a3),sysarg(a4),sysarg(a5),sysarg(a6))
+#define syscall7(n,a1,a2,a3,a4,a5,a6,a7) _syscall7(n,sysarg(a1),sysarg(a2),sysarg(a3),sysarg(a4),sysarg(a5),sysarg(a6),sysarg(a7))
+
+#define __SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
+#define __SYSCALL_NARGS(...) __SYSCALL_NARGS_X(__VA_ARGS__,7,6,5,4,3,2,1,0,)
+#define __SYSCALL_CONCAT_X(a,b) a##b
+#define __SYSCALL_CONCAT(a,b) __SYSCALL_CONCAT_X(a,b)
+#define __SYSCALL_DISP(b,...) __SYSCALL_CONCAT(b,__SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
+
+#define syscall(...) __SYSCALL_DISP(syscall,__VA_ARGS__)
+
diff --git a/sys/src/mmap.c b/sys/src/mmap.c
new file mode 100644
index 0000000..fb5c5f4
--- /dev/null
+++ b/sys/src/mmap.c
@@ -0,0 +1 @@
+#include "internal.h"
diff --git a/sys/src/open.c b/sys/src/open.c
new file mode 100644
index 0000000..02d2ca8
--- /dev/null
+++ b/sys/src/open.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+int
+sys·open(char *path, int flag, int mode)
+{
+    return syscall(·Open, flag, mode);
+}
diff --git a/sys/src/read.c b/sys/src/read.c
new file mode 100644
index 0000000..3aa3e29
--- /dev/null
+++ b/sys/src/read.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+intptr
+sys·read(int fd, intptr len, void *buf)
+{
+    return syscall(·Read, fd, buf, len);
+}
diff --git a/sys/src/write.c b/sys/src/write.c
new file mode 100644
index 0000000..c1faff5
--- /dev/null
+++ b/sys/src/write.c
@@ -0,0 +1,7 @@
+#include "internal.h"
+
+intptr
+sys·write(int fd, intptr size, intptr len, void *buf)
+{
+    return syscall(·Write, fd, buf, size*len);
+}