Abstract POSIX filesystem functions (#2585)

To allow non-POSIX platforms such as Windows to support WASI libc
filesystem functionality, create a set of wrapper functions which provide a
platform-agnostic interface to interact with the host filesystem. For now,
the Windows implementation is stubbed but this will be implemented
properly in a future PR. There are no functional changes in this change,
just a reorganization of code to move any direct POSIX references out of
posix.c in the libc implementation into posix_file.c under the shared
POSIX sources.

See https://github.com/bytecodealliance/wasm-micro-runtime/issues/2495 for a
more detailed overview of the plan to port the WASI libc filesystem to Windows.

core/shared/platform/common/libc-util/libc_errno.c

@@ -0,0 +1,256 @@
+/*
+ * Copyright (C) 2023 Intel Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include "errno.h"
+#include "libc_errno.h"
+
+__wasi_errno_t
+convert_errno(int error)
+{
+    // The C standard library only requires EDOM, EILSEQ and ERANGE to be
+    // defined. Other error codes are POSIX-specific and hence may or may
+    // not be available on non-POSIX platforms.
+    __wasi_errno_t code = __WASI_ENOSYS;
+#define X(v)               \
+    case v:                \
+        code = __WASI_##v; \
+        break;
+    switch (error) {
+        X(EDOM)
+        X(EILSEQ)
+        X(ERANGE)
+#ifdef E2BIG
+        X(E2BIG)
+#endif
+#ifdef EACCES
+        X(EACCES)
+#endif
+#ifdef EADDRINUSE
+        X(EADDRINUSE)
+#endif
+#ifdef EADDRNOTAVAIL
+        X(EADDRNOTAVAIL)
+#endif
+#ifdef EAFNOSUPPORT
+        X(EAFNOSUPPORT)
+#endif
+#ifdef EAGAIN
+        X(EAGAIN)
+#endif
+#ifdef EALREADY
+        X(EALREADY)
+#endif
+#ifdef EBADF
+        X(EBADF)
+#endif
+#ifdef EBADMSG
+        X(EBADMSG)
+#endif
+#ifdef EBUSY
+        X(EBUSY)
+#endif
+#ifdef ECANCELED
+        X(ECANCELED)
+#endif
+#ifdef ECHILD
+        X(ECHILD)
+#endif
+#ifdef ECONNABORTED
+        X(ECONNABORTED)
+#endif
+#ifdef ECONNREFUSED
+        X(ECONNREFUSED)
+#endif
+#ifdef ECONNRESET
+        X(ECONNRESET)
+#endif
+#ifdef EDEADLK
+        X(EDEADLK)
+#endif
+#ifdef EDESTADDRREQ
+        X(EDESTADDRREQ)
+#endif
+#ifdef EDQUOT
+        X(EDQUOT)
+#endif
+#ifdef EEXIST
+        X(EEXIST)
+#endif
+#ifdef EFAULT
+        X(EFAULT)
+#endif
+#ifdef EFBIG
+        X(EFBIG)
+#endif
+#ifdef EHOSTUNREACH
+        X(EHOSTUNREACH)
+#endif
+#ifdef EIDRM
+        X(EIDRM)
+#endif
+#ifdef EINPROGRESS
+        X(EINPROGRESS)
+#endif
+#ifdef EINTR
+        X(EINTR)
+#endif
+#ifdef EINVAL
+        X(EINVAL)
+#endif
+#ifdef EIO
+        X(EIO)
+#endif
+#ifdef EISCONN
+        X(EISCONN)
+#endif
+#ifdef EISDIR
+        X(EISDIR)
+#endif
+#ifdef ELOOP
+        X(ELOOP)
+#endif
+#ifdef EMFILE
+        X(EMFILE)
+#endif
+#ifdef EMLINK
+        X(EMLINK)
+#endif
+#ifdef EMSGSIZE
+        X(EMSGSIZE)
+#endif
+#ifdef EMULTIHOP
+        X(EMULTIHOP)
+#endif
+#ifdef ENAMETOOLONG
+        X(ENAMETOOLONG)
+#endif
+#ifdef ENETDOWN
+        X(ENETDOWN)
+#endif
+#ifdef ENETRESET
+        X(ENETRESET)
+#endif
+#ifdef ENETUNREACH
+        X(ENETUNREACH)
+#endif
+#ifdef ENFILE
+        X(ENFILE)
+#endif
+#ifdef ENOBUFS
+        X(ENOBUFS)
+#endif
+#ifdef ENODEV
+        X(ENODEV)
+#endif
+#ifdef ENOENT
+        X(ENOENT)
+#endif
+#ifdef ENOEXEC
+        X(ENOEXEC)
+#endif
+#ifdef ENOLCK
+        X(ENOLCK)
+#endif
+#ifdef ENOLINK
+        X(ENOLINK)
+#endif
+#ifdef ENOMEM
+        X(ENOMEM)
+#endif
+#ifdef ENOMSG
+        X(ENOMSG)
+#endif
+#ifdef ENOPROTOOPT
+        X(ENOPROTOOPT)
+#endif
+#ifdef ENOSPC
+        X(ENOSPC)
+#endif
+#ifdef ENOSYS
+        X(ENOSYS)
+#endif
+#ifdef ENOTCAPABLE
+        X(ENOTCAPABLE)
+#endif
+#ifdef ENOTCONN
+        X(ENOTCONN)
+#endif
+#ifdef ENOTDIR
+        X(ENOTDIR)
+#endif
+#ifdef ENOTEMPTY
+        X(ENOTEMPTY)
+#endif
+#ifdef ENOTRECOVERABLE
+        X(ENOTRECOVERABLE)
+#endif
+#ifdef ENOTSOCK
+        X(ENOTSOCK)
+#endif
+#ifdef ENOTSUP
+        X(ENOTSUP)
+#endif
+#ifdef ENOTTY
+        X(ENOTTY)
+#endif
+#ifdef ENXIO
+        X(ENXIO)
+#endif
+#ifdef EOVERFLOW
+        X(EOVERFLOW)
+#endif
+#ifdef EOWNERDEAD
+        X(EOWNERDEAD)
+#endif
+#ifdef EPERM
+        X(EPERM)
+#endif
+#ifdef EPIPE
+        X(EPIPE)
+#endif
+#ifdef EPROTO
+        X(EPROTO)
+#endif
+#ifdef EPROTONOSUPPORT
+        X(EPROTONOSUPPORT)
+#endif
+#ifdef EPROTOTYPE
+        X(EPROTOTYPE)
+#endif
+#ifdef EROFS
+        X(EROFS)
+#endif
+#ifdef ESPIPE
+        X(ESPIPE)
+#endif
+#ifdef ESRCH
+        X(ESRCH)
+#endif
+#ifdef ESTALE
+        X(ESTALE)
+#endif
+#ifdef ETIMEDOUT
+        X(ETIMEDOUT)
+#endif
+#ifdef ETXTBSY
+        X(ETXTBSY)
+#endif
+#ifdef EXDEV
+        X(EXDEV)
+#endif
+        default:
+#ifdef EOPNOTSUPP
+            if (error == EOPNOTSUPP)
+                code = __WASI_ENOTSUP;
+#endif
+#ifdef EWOULDBLOCK
+            if (error == EWOULDBLOCK)
+                code = __WASI_EAGAIN;
+#endif
+            break;
+    }
+#undef X
+    return code;
+}

core/shared/platform/common/libc-util/libc_errno.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2023 Intel Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#ifndef WASI_ERRNO_H
+#define WASI_ERRNO_H
+
+#include "platform_wasi.h"
+
+// Converts an errno error code to a WASI error code.
+__wasi_errno_t
+convert_errno(int error);
+
+#endif /* end of WASI_ERRNO_H */

core/shared/platform/common/libc-util/platform_common_libc_util.cmake

@@ -0,0 +1,8 @@
+# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ 
+set (PLATFORM_COMMON_LIBC_UTIL_DIR ${CMAKE_CURRENT_LIST_DIR})
+
+include_directories(${PLATFORM_COMMON_LIBC_UTIL_DIR})
+
+file (GLOB_RECURSE PLATFORM_COMMON_LIBC_UTIL_SOURCE ${PLATFORM_COMMON_LIBC_UTIL_DIR}/*.c)

core/shared/platform/common/posix/platform_api_posix.cmake

@@ -5,4 +5,11 @@ set (PLATFORM_COMMON_POSIX_DIR ${CMAKE_CURRENT_LIST_DIR})
 
 file (GLOB_RECURSE source_all ${PLATFORM_COMMON_POSIX_DIR}/*.c)
 
+if (NOT WAMR_BUILD_LIBC_WASI EQUAL 1)
+    list(REMOVE_ITEM source_all ${PLATFORM_COMMON_POSIX_DIR}/posix_file.c)
+else()
+    include (${CMAKE_CURRENT_LIST_DIR}/../libc-util/platform_common_libc_util.cmake)
+    set(source_all ${source_all} ${PLATFORM_COMMON_LIBC_UTIL_SOURCE})
+endif()
+
 set (PLATFORM_COMMON_POSIX_SOURCE ${source_all} )