From 6c05f32397d4b424cc7075f553ff236eb635eea4 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:15:48 -0400
Subject: [PATCH 01/20] stdout in wasmfs

---
 src/modules.js              | 11 ++++++--
 src/preamble.js             |  2 +-
 src/settings.js             |  4 +++
 system/lib/fetch/wasmfs.cpp | 55 +++++++++++++++++++++++++++++++++++++
 tools/system_libs.py        |  5 ++++
 5 files changed, 73 insertions(+), 4 deletions(-)
 create mode 100644 system/lib/fetch/wasmfs.cpp

diff --git a/src/modules.js b/src/modules.js
index a1167ba9bf44d..b35a32f701c89 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -61,14 +61,17 @@ var LibraryManager = {
       'library_formatString.js',
       'library_math.js',
       'library_path.js',
-      'library_syscall.js',
       'library_html5.js',
       'library_stack_trace.js',
-      'library_wasi.js',
       'library_int53.js',
       'library_dylink.js'
     ];
 
+    if (!WASMFS) {
+      libraries.push('library_syscall.js')
+      libraries.push('library_wasi.js')
+    }
+
     if (LINK_AS_CXX && !EXCEPTION_HANDLING) {
       if (DISABLE_EXCEPTION_THROWING) {
         libraries.push('library_exceptions_stub.js');
@@ -93,7 +96,9 @@ var LibraryManager = {
       libraries.push('library_html5_webgl.js');
     }
 
-    if (FILESYSTEM) {
+    if (WASMFS) {
+      libraries.push('library_wasmfs.js')
+    } else if (FILESYSTEM) {
       // Core filesystem libraries (always linked against, unless -s FILESYSTEM=0 is specified)
       libraries = libraries.concat([
         'library_fs.js',
diff --git a/src/preamble.js b/src/preamble.js
index 4fba1b2cb6940..38574e61cdf39 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -617,7 +617,7 @@ function abort(what) {
 
 #include "memoryprofiler.js"
 
-#if ASSERTIONS && !('$FS' in addedLibraryItems) && !ASMFS
+#if ASSERTIONS && !('$FS' in addedLibraryItems) && !ASMFS && !WASMFS
 // show errors on likely calls to FS when it was not included
 var FS = {
   error: function() {
diff --git a/src/settings.js b/src/settings.js
index fd3d02b7ee17d..b9045c3672495 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1635,6 +1635,10 @@ var FETCH = 0;
 // [link]
 var ASMFS = 0;
 
+// If set to 1, uses new filesystem implementation
+// [link]
+var WASMFS = 0;
+
 // If set to 1, embeds all subresources in the emitted file as base64 string
 // literals. Embedded subresources may include (but aren't limited to) wasm,
 // asm.js, and static memory initialization code.
diff --git a/system/lib/fetch/wasmfs.cpp b/system/lib/fetch/wasmfs.cpp
new file mode 100644
index 0000000000000..2a5aa15f02c4f
--- /dev/null
+++ b/system/lib/fetch/wasmfs.cpp
@@ -0,0 +1,55 @@
+// // Copyright 2021 The Emscripten Authors.  All rights reserved.
+// // Emscripten is available under two separate licenses, the MIT license and the
+// // University of Illinois/NCSA Open Source License.  Both these licenses can be
+// // found in the LICENSE file.
+
+#include <stdlib.h>
+#define __NEED_struct_iovec
+#include <emscripten/emscripten.h>
+#include <wasi/api.h>
+
+extern "C" {
+
+  __wasi_errno_t __wasi_fd_write( __wasi_fd_t fd, const __wasi_ciovec_t *iovs, size_t iovs_len, __wasi_size_t *nwritten) {
+    if (fd == 1 || fd == 2) {
+      MAIN_THREAD_EM_ASM({
+        var buffer = [];
+        var fd = $0;
+        var iovs = $1;
+        var iovs_len = $2;
+        var nwritten = $3;
+        var num = 0;
+        for (var i = 0; i < iovs_len; i++) {
+          var ptr = HEAP32[(((iovs)+(i*8))>>2)];
+          var len = HEAP32[(((iovs)+(i*8 + 4))>>2)];
+          for (var j = 0; j < len; j++) {
+            if (HEAPU8[ptr+j] === 0 || HEAPU8[ptr+j] === 10) {
+              (fd === 1 ? out : err)(UTF8ArrayToString(buffer, 0));
+              buffer.length = 0;
+            } else {
+              buffer.push(HEAPU8[ptr+j]);
+            }
+          }
+          num += len;
+        }
+        HEAP32[((nwritten)>>2)] = num;
+      }, fd, iovs, iovs_len, nwritten);
+    }
+    return 0;
+  }
+
+  __wasi_errno_t __wasi_fd_seek(__wasi_fd_t fd, __wasi_filedelta_t offset, __wasi_whence_t whence, __wasi_filesize_t *newoffset)
+  {
+    abort();
+  }
+
+  __wasi_errno_t __wasi_fd_close(__wasi_fd_t fd)
+  {
+    abort();
+  }
+
+  __wasi_errno_t __wasi_fd_read(__wasi_fd_t fd, const __wasi_iovec_t *iovs, size_t iovs_len, __wasi_size_t *nread)
+  {
+    abort();
+  }
+}
\ No newline at end of file
diff --git a/tools/system_libs.py b/tools/system_libs.py
index d59180a5e7b9e..c033ff3991060 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -1283,6 +1283,11 @@ def can_build(self):
     # https://github.com/emscripten-core/emscripten/issues/9534
     return True
 
+class libwasmfs(MTLibrary):
+  name = 'libwasmfs'
+
+  def get_files(self):
+    return [utils.path_from_root('system/lib/fetch/wasmfs.cpp')]
 
 class libhtml5(Library):
   name = 'libhtml5'

From 7b7069093f13c2d4c0f5076241783e5a16cdf456 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:20:32 -0400
Subject: [PATCH 02/20] emcc updated

---
 emcc.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/emcc.py b/emcc.py
index 88fd76a85b5b6..8a128e25fc001 100755
--- a/emcc.py
+++ b/emcc.py
@@ -1767,6 +1767,12 @@ def default_setting(name, new_default):
     settings.FETCH = 1
     settings.JS_LIBRARIES.append((0, 'library_asmfs.js'))
 
+  if settings.WASMFS:
+    state.forced_stdlibs.append('libwasmfs')
+    settings.FILESYSTEM = 0
+    settings.SYSCALLS_REQUIRE_FILESYSTEM = 0
+    # settings.JS_LIBRARIES.append((0, 'library_wasmfs.js'))
+
   # Explicitly drop linking in a malloc implementation if program is not using any dynamic allocation calls.
   if not settings.USES_DYNAMIC_ALLOC:
     settings.MALLOC = 'none'

From 6939f12e9f4f7abed1da3441a57ca126e6eef24a Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:22:54 -0400
Subject: [PATCH 03/20] add library_wasmfs

---
 src/library_wasmfs.js | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 src/library_wasmfs.js

diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
new file mode 100644
index 0000000000000..49cae0303a892
--- /dev/null
+++ b/src/library_wasmfs.js
@@ -0,0 +1,8 @@
+var WASMFS = {
+    $WASMFS : {}
+
+}
+
+mergeInto(LibraryManager.library, WASMFS);
+
+DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push('$WASMFS');
\ No newline at end of file

From f2ce6b426e42527308ca4efe53d388f73069708e Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:26:59 -0400
Subject: [PATCH 04/20] add library_wasmfs to emcc.py

---
 emcc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/emcc.py b/emcc.py
index 8a128e25fc001..1ed0e4801cc47 100755
--- a/emcc.py
+++ b/emcc.py
@@ -1771,7 +1771,7 @@ def default_setting(name, new_default):
     state.forced_stdlibs.append('libwasmfs')
     settings.FILESYSTEM = 0
     settings.SYSCALLS_REQUIRE_FILESYSTEM = 0
-    # settings.JS_LIBRARIES.append((0, 'library_wasmfs.js'))
+    settings.JS_LIBRARIES.append((0, 'library_wasmfs.js'))
 
   # Explicitly drop linking in a malloc implementation if program is not using any dynamic allocation calls.
   if not settings.USES_DYNAMIC_ALLOC:

From d1b1e81c6dcef4f2e85860f9956bb749544261aa Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:28:57 -0400
Subject: [PATCH 05/20] whitespace

---
 system/lib/fetch/wasmfs.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/lib/fetch/wasmfs.cpp b/system/lib/fetch/wasmfs.cpp
index 2a5aa15f02c4f..5264af60a7937 100644
--- a/system/lib/fetch/wasmfs.cpp
+++ b/system/lib/fetch/wasmfs.cpp
@@ -52,4 +52,4 @@ extern "C" {
   {
     abort();
   }
-}
\ No newline at end of file
+}

From f26043d69b5901d5ef81bd69cd110f25b7c5283d Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:30:10 -0400
Subject: [PATCH 06/20] remove default list

---
 src/library_wasmfs.js | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
index 49cae0303a892..afdfa4db60990 100644
--- a/src/library_wasmfs.js
+++ b/src/library_wasmfs.js
@@ -4,5 +4,3 @@ var WASMFS = {
 }
 
 mergeInto(LibraryManager.library, WASMFS);
-
-DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push('$WASMFS');
\ No newline at end of file

From 84d4bc5d2bf0b4a46a121418958036d5c5e984e3 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Wed, 22 Sep 2021 19:35:14 -0400
Subject: [PATCH 07/20] add blank lines

---
 tools/system_libs.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/system_libs.py b/tools/system_libs.py
index c033ff3991060..add54a4012247 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -1283,12 +1283,14 @@ def can_build(self):
     # https://github.com/emscripten-core/emscripten/issues/9534
     return True
 
+
 class libwasmfs(MTLibrary):
   name = 'libwasmfs'
 
   def get_files(self):
     return [utils.path_from_root('system/lib/fetch/wasmfs.cpp')]
 
+
 class libhtml5(Library):
   name = 'libhtml5'
 

From 92d5304f69c4a952f8457d3be286c360d6e1254a Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Thu, 23 Sep 2021 11:13:45 -0400
Subject: [PATCH 08/20] addressed comments

---
 emcc.py                                |  2 +-
 src/library_wasmfs.js                  |  6 ---
 src/modules.js                         | 11 ++--
 src/settings.js                        |  2 +
 system/lib/fetch/wasmfs.cpp            | 55 --------------------
 system/lib/wasmfs/wasmfs.cpp           | 72 ++++++++++++++++++++++++++
 tests/core/test_wasmfs_hello_world.c   | 14 +++++
 tests/core/test_wasmfs_hello_world.out |  1 +
 tests/test_core.py                     | 11 ++++
 tools/system_libs.py                   |  2 +-
 10 files changed, 105 insertions(+), 71 deletions(-)
 delete mode 100644 src/library_wasmfs.js
 delete mode 100644 system/lib/fetch/wasmfs.cpp
 create mode 100644 system/lib/wasmfs/wasmfs.cpp
 create mode 100644 tests/core/test_wasmfs_hello_world.c
 create mode 100644 tests/core/test_wasmfs_hello_world.out

diff --git a/emcc.py b/emcc.py
index 1ed0e4801cc47..9c6e02601b17e 100755
--- a/emcc.py
+++ b/emcc.py
@@ -1771,7 +1771,7 @@ def default_setting(name, new_default):
     state.forced_stdlibs.append('libwasmfs')
     settings.FILESYSTEM = 0
     settings.SYSCALLS_REQUIRE_FILESYSTEM = 0
-    settings.JS_LIBRARIES.append((0, 'library_wasmfs.js'))
+    # settings.JS_LIBRARIES.append((0, 'library_wasmfs.js')) TODO: Add in future PR
 
   # Explicitly drop linking in a malloc implementation if program is not using any dynamic allocation calls.
   if not settings.USES_DYNAMIC_ALLOC:
diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
deleted file mode 100644
index afdfa4db60990..0000000000000
--- a/src/library_wasmfs.js
+++ /dev/null
@@ -1,6 +0,0 @@
-var WASMFS = {
-    $WASMFS : {}
-
-}
-
-mergeInto(LibraryManager.library, WASMFS);
diff --git a/src/modules.js b/src/modules.js
index b35a32f701c89..a1167ba9bf44d 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -61,17 +61,14 @@ var LibraryManager = {
       'library_formatString.js',
       'library_math.js',
       'library_path.js',
+      'library_syscall.js',
       'library_html5.js',
       'library_stack_trace.js',
+      'library_wasi.js',
       'library_int53.js',
       'library_dylink.js'
     ];
 
-    if (!WASMFS) {
-      libraries.push('library_syscall.js')
-      libraries.push('library_wasi.js')
-    }
-
     if (LINK_AS_CXX && !EXCEPTION_HANDLING) {
       if (DISABLE_EXCEPTION_THROWING) {
         libraries.push('library_exceptions_stub.js');
@@ -96,9 +93,7 @@ var LibraryManager = {
       libraries.push('library_html5_webgl.js');
     }
 
-    if (WASMFS) {
-      libraries.push('library_wasmfs.js')
-    } else if (FILESYSTEM) {
+    if (FILESYSTEM) {
       // Core filesystem libraries (always linked against, unless -s FILESYSTEM=0 is specified)
       libraries = libraries.concat([
         'library_fs.js',
diff --git a/src/settings.js b/src/settings.js
index b9045c3672495..2d6b12d94428d 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1635,6 +1635,8 @@ var FETCH = 0;
 // [link]
 var ASMFS = 0;
 
+// ATTENTION [WIP]: Experimental feature, use at your own risk
+// Will eventually replace current JS file system implementation
 // If set to 1, uses new filesystem implementation
 // [link]
 var WASMFS = 0;
diff --git a/system/lib/fetch/wasmfs.cpp b/system/lib/fetch/wasmfs.cpp
deleted file mode 100644
index 5264af60a7937..0000000000000
--- a/system/lib/fetch/wasmfs.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-// // Copyright 2021 The Emscripten Authors.  All rights reserved.
-// // Emscripten is available under two separate licenses, the MIT license and the
-// // University of Illinois/NCSA Open Source License.  Both these licenses can be
-// // found in the LICENSE file.
-
-#include <stdlib.h>
-#define __NEED_struct_iovec
-#include <emscripten/emscripten.h>
-#include <wasi/api.h>
-
-extern "C" {
-
-  __wasi_errno_t __wasi_fd_write( __wasi_fd_t fd, const __wasi_ciovec_t *iovs, size_t iovs_len, __wasi_size_t *nwritten) {
-    if (fd == 1 || fd == 2) {
-      MAIN_THREAD_EM_ASM({
-        var buffer = [];
-        var fd = $0;
-        var iovs = $1;
-        var iovs_len = $2;
-        var nwritten = $3;
-        var num = 0;
-        for (var i = 0; i < iovs_len; i++) {
-          var ptr = HEAP32[(((iovs)+(i*8))>>2)];
-          var len = HEAP32[(((iovs)+(i*8 + 4))>>2)];
-          for (var j = 0; j < len; j++) {
-            if (HEAPU8[ptr+j] === 0 || HEAPU8[ptr+j] === 10) {
-              (fd === 1 ? out : err)(UTF8ArrayToString(buffer, 0));
-              buffer.length = 0;
-            } else {
-              buffer.push(HEAPU8[ptr+j]);
-            }
-          }
-          num += len;
-        }
-        HEAP32[((nwritten)>>2)] = num;
-      }, fd, iovs, iovs_len, nwritten);
-    }
-    return 0;
-  }
-
-  __wasi_errno_t __wasi_fd_seek(__wasi_fd_t fd, __wasi_filedelta_t offset, __wasi_whence_t whence, __wasi_filesize_t *newoffset)
-  {
-    abort();
-  }
-
-  __wasi_errno_t __wasi_fd_close(__wasi_fd_t fd)
-  {
-    abort();
-  }
-
-  __wasi_errno_t __wasi_fd_read(__wasi_fd_t fd, const __wasi_iovec_t *iovs, size_t iovs_len, __wasi_size_t *nread)
-  {
-    abort();
-  }
-}
diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
new file mode 100644
index 0000000000000..00482f7e8f857
--- /dev/null
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -0,0 +1,72 @@
+// // Copyright 2021 The Emscripten Authors.  All rights reserved.
+// // Emscripten is available under two separate licenses, the MIT license and the
+// // University of Illinois/NCSA Open Source License.  Both these licenses can be
+// // found in the LICENSE file.
+// // wasmfs.cpp will implement a new file system that replaces the existing JS filesystem
+// // Current Status: Work in Progress.
+// // See https://github.com/emscripten-core/emscripten/issues/15041
+
+#include <stdlib.h>
+#define __NEED_struct_iovec
+#include <emscripten/emscripten.h>
+#include <wasi/api.h>
+
+extern "C" {
+
+__wasi_errno_t __wasi_fd_write(
+  __wasi_fd_t fd, const __wasi_ciovec_t* iovs, size_t iovs_len, __wasi_size_t* nwritten) {
+  // FD 1 = STDOUT
+  // FD 2 = STDERR
+  // Temporary hardcoding of filedescriptor values
+  // TODO: May not want to proxy stderr (fd == 2) to the main thread
+  // This will not not show in HTML, a console.warn in a worker is suffficient
+  // This would be a change from the current FS
+  if (fd == 1 || fd == 2) {
+    MAIN_THREAD_EM_ASM(
+      {
+        var buffer = [];
+        var fd = $0;
+        var iovs = $1;
+        var iovs_len = $2;
+        var nwritten = $3;
+        var num = 0;
+        for (var i = 0; i < iovs_len; i++) {
+          var ptr = HEAP32[iovs + i * 8 >> 2];
+          var len = HEAP32[iovs + i * 8 + 4 >> 2];
+          for (var j = 0; j < len; j++) {
+            if (HEAPU8[ptr + j] == 0 || HEAPU8[ptr + j] == 10) {
+              (fd == 1 ? out : err)(UTF8ArrayToString(buffer, 0));
+              buffer.length = 0;
+            } else {
+              buffer.push(HEAPU8[ptr + j]);
+            }
+          }
+          num += len;
+        }
+        HEAP32[((nwritten) >> 2)] = num;
+      },
+      fd, iovs, iovs_len, nwritten);
+  }
+  return 0;
+}
+
+__wasi_errno_t __wasi_fd_seek(
+  __wasi_fd_t fd, __wasi_filedelta_t offset, __wasi_whence_t whence, __wasi_filesize_t* newoffset) {
+  EM_ASM({out(`${$0} or __wasi_fd_seek has been temporarily stubbed and is inert`)},
+    __PRETTY_FUNCTION__);
+  abort();
+}
+
+__wasi_errno_t __wasi_fd_close(__wasi_fd_t fd) {
+  EM_ASM({out(`${$0} or __wasi_fd_close has been temporarily stubbed and is inert`)},
+    __PRETTY_FUNCTION__);
+  abort();
+}
+
+__wasi_errno_t __wasi_fd_read(
+  __wasi_fd_t fd, const __wasi_iovec_t* iovs, size_t iovs_len, __wasi_size_t* nread) {
+  EM_ASM({out(`${$0} or __wasi_fd_read has been temporarily stubbed and is inert`)},
+    __PRETTY_FUNCTION__);
+  abort();
+}
+}
diff --git a/tests/core/test_wasmfs_hello_world.c b/tests/core/test_wasmfs_hello_world.c
new file mode 100644
index 0000000000000..21cc9440d2b63
--- /dev/null
+++ b/tests/core/test_wasmfs_hello_world.c
@@ -0,0 +1,14 @@
+/*
+ * Copyright 2021 The Emscripten Authors.  All rights reserved.
+ * Emscripten is available under two separate licenses, the MIT license and the
+ * University of Illinois/NCSA Open Source License.  Both these licenses can be
+ * found in the LICENSE file.
+ */
+
+// Testing wasmfs to show library is built and linked successfully
+
+#include <stdio.h>
+int main() {
+  printf("wasmfs!\n");
+  return 0;
+}
diff --git a/tests/core/test_wasmfs_hello_world.out b/tests/core/test_wasmfs_hello_world.out
new file mode 100644
index 0000000000000..2258f23197a25
--- /dev/null
+++ b/tests/core/test_wasmfs_hello_world.out
@@ -0,0 +1 @@
+wasmfs!
\ No newline at end of file
diff --git a/tests/test_core.py b/tests/test_core.py
index d934b1c4dc283..a09cbc107a09a 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -139,6 +139,12 @@ def can_do_standalone(self):
       '-fsanitize=address' not in self.emcc_args
 
 
+def also_with_wasmfs(func):
+  def decorated(self):
+    self.set_setting('WASMFS')
+  return decorated
+
+
 # Impure means a test that cannot run in a wasm VM yet, as it is not 100%
 # standalone. We can still run them with the JS code though.
 def also_with_standalone_wasm(wasm2c=False, impure=False):
@@ -313,6 +319,11 @@ def test_hello_world(self):
     # must not emit this unneeded internal thing
     self.assertNotContained('EMSCRIPTEN_GENERATED_FUNCTIONS', read_file('test_hello_world.js'))
 
+  @also_with_wasmfs
+  def test_wasmfs_hello_world(self):
+    self.do_core_test('test_wasmfs_hello_world.c')
+    self.assertNotContained('EMSCRIPTEN_GENERATED_FUNCTIONS', read_file('test_wasmfs_hello_world.js'))
+
   def test_wasm_synchronous_compilation(self):
     self.set_setting('STRICT_JS')
     self.set_setting('WASM_ASYNC_COMPILATION', 0)
diff --git a/tools/system_libs.py b/tools/system_libs.py
index add54a4012247..c1386be6b5234 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -1288,7 +1288,7 @@ class libwasmfs(MTLibrary):
   name = 'libwasmfs'
 
   def get_files(self):
-    return [utils.path_from_root('system/lib/fetch/wasmfs.cpp')]
+    return [utils.path_from_root('system/lib/wasmfs/wasmfs.cpp')]
 
 
 class libhtml5(Library):

From 39729101283ea0d38bdd744908d139f09fa32c7d Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Thu, 23 Sep 2021 11:27:40 -0400
Subject: [PATCH 09/20] white space

---
 tests/core/test_wasmfs_hello_world.out | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/core/test_wasmfs_hello_world.out b/tests/core/test_wasmfs_hello_world.out
index 2258f23197a25..d41c06a9984e3 100644
--- a/tests/core/test_wasmfs_hello_world.out
+++ b/tests/core/test_wasmfs_hello_world.out
@@ -1 +1 @@
-wasmfs!
\ No newline at end of file
+wasmfs!

From a301fac4e8c40fd3cbcd62cc810a63911c6dc2be Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Thu, 23 Sep 2021 11:59:45 -0400
Subject: [PATCH 10/20] remove parens

---
 system/lib/wasmfs/wasmfs.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 00482f7e8f857..da13a6bb2a506 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -43,7 +43,7 @@ __wasi_errno_t __wasi_fd_write(
           }
           num += len;
         }
-        HEAP32[((nwritten) >> 2)] = num;
+        HEAP32[nwritten >> 2] = num;
       },
       fd, iovs, iovs_len, nwritten);
   }

From 117be99148b1c5d17b0a83a1a33b030967769583 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Thu, 23 Sep 2021 16:37:46 -0400
Subject: [PATCH 11/20] grammar and tests fix

---
 src/settings.js                        |  6 +++---
 system/lib/wasmfs/wasmfs.cpp           | 21 ++++++++++-----------
 tests/common.py                        |  1 +
 tests/core/test_wasmfs_hello_world.c   | 14 --------------
 tests/core/test_wasmfs_hello_world.out |  1 -
 tests/test_core.py                     | 10 +++++-----
 6 files changed, 19 insertions(+), 34 deletions(-)
 delete mode 100644 tests/core/test_wasmfs_hello_world.c
 delete mode 100644 tests/core/test_wasmfs_hello_world.out

diff --git a/src/settings.js b/src/settings.js
index 2d6b12d94428d..e6d0296d218b4 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -1635,9 +1635,9 @@ var FETCH = 0;
 // [link]
 var ASMFS = 0;
 
-// ATTENTION [WIP]: Experimental feature, use at your own risk
-// Will eventually replace current JS file system implementation
-// If set to 1, uses new filesystem implementation
+// ATTENTION [WIP]: Experimental feature. Please use at your own risk.
+// This will eventually replace the current JS file system implementation.
+// If set to 1, uses new filesystem implementation.
 // [link]
 var WASMFS = 0;
 
diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index da13a6bb2a506..4ee576af88134 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -2,9 +2,9 @@
 // // Emscripten is available under two separate licenses, the MIT license and the
 // // University of Illinois/NCSA Open Source License.  Both these licenses can be
 // // found in the LICENSE file.
-// // wasmfs.cpp will implement a new file system that replaces the existing JS filesystem
+// // wasmfs.cpp will implement a new file system that replaces the existing JS filesystem.
 // // Current Status: Work in Progress.
-// // See https://github.com/emscripten-core/emscripten/issues/15041
+// // See https://github.com/emscripten-core/emscripten/issues/15041.
 
 #include <stdlib.h>
 #define __NEED_struct_iovec
@@ -15,12 +15,11 @@ extern "C" {
 
 __wasi_errno_t __wasi_fd_write(
   __wasi_fd_t fd, const __wasi_ciovec_t* iovs, size_t iovs_len, __wasi_size_t* nwritten) {
-  // FD 1 = STDOUT
-  // FD 2 = STDERR
-  // Temporary hardcoding of filedescriptor values
-  // TODO: May not want to proxy stderr (fd == 2) to the main thread
-  // This will not not show in HTML, a console.warn in a worker is suffficient
-  // This would be a change from the current FS
+  // FD 1 = STDOUT and FD 2 = STDERR.
+  // Temporary hardcoding of filedescriptor values.
+  // TODO: May not want to proxy stderr (fd == 2) to the main thread.
+  // This will not not show in HTML, a console.warn in a worker is suffficient.
+  // This would be a change from the current FS.
   if (fd == 1 || fd == 2) {
     MAIN_THREAD_EM_ASM(
       {
@@ -52,20 +51,20 @@ __wasi_errno_t __wasi_fd_write(
 
 __wasi_errno_t __wasi_fd_seek(
   __wasi_fd_t fd, __wasi_filedelta_t offset, __wasi_whence_t whence, __wasi_filesize_t* newoffset) {
-  EM_ASM({out(`${$0} or __wasi_fd_seek has been temporarily stubbed and is inert`)},
+  EM_ASM({out($0 + ' or __wasi_fd_seek has been temporarily stubbed and is inert')},
     __PRETTY_FUNCTION__);
   abort();
 }
 
 __wasi_errno_t __wasi_fd_close(__wasi_fd_t fd) {
-  EM_ASM({out(`${$0} or __wasi_fd_close has been temporarily stubbed and is inert`)},
+  EM_ASM({out($0 + ' or __wasi_fd_close has been temporarily stubbed and is inert')},
     __PRETTY_FUNCTION__);
   abort();
 }
 
 __wasi_errno_t __wasi_fd_read(
   __wasi_fd_t fd, const __wasi_iovec_t* iovs, size_t iovs_len, __wasi_size_t* nread) {
-  EM_ASM({out(`${$0} or __wasi_fd_read has been temporarily stubbed and is inert`)},
+  EM_ASM({out($0 + ' or __wasi_fd_read has been temporarily stubbed and is inert')},
     __PRETTY_FUNCTION__);
   abort();
 }
diff --git a/tests/common.py b/tests/common.py
index 5f8cf92e1044a..0f1d76cfc241d 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -541,6 +541,7 @@ def verify_es5(self, filename):
     es_check_env = os.environ.copy()
     es_check_env['PATH'] = os.path.dirname(config.NODE_JS[0]) + os.pathsep + es_check_env['PATH']
     try:
+      # Comment out --quiet if more detailed error logging is needed
       shared.run_process(es_check + ['es5', os.path.abspath(filename), '--quiet'], stderr=PIPE, env=es_check_env)
     except subprocess.CalledProcessError as e:
       print(e.stderr)
diff --git a/tests/core/test_wasmfs_hello_world.c b/tests/core/test_wasmfs_hello_world.c
deleted file mode 100644
index 21cc9440d2b63..0000000000000
--- a/tests/core/test_wasmfs_hello_world.c
+++ /dev/null
@@ -1,14 +0,0 @@
-/*
- * Copyright 2021 The Emscripten Authors.  All rights reserved.
- * Emscripten is available under two separate licenses, the MIT license and the
- * University of Illinois/NCSA Open Source License.  Both these licenses can be
- * found in the LICENSE file.
- */
-
-// Testing wasmfs to show library is built and linked successfully
-
-#include <stdio.h>
-int main() {
-  printf("wasmfs!\n");
-  return 0;
-}
diff --git a/tests/core/test_wasmfs_hello_world.out b/tests/core/test_wasmfs_hello_world.out
deleted file mode 100644
index d41c06a9984e3..0000000000000
--- a/tests/core/test_wasmfs_hello_world.out
+++ /dev/null
@@ -1 +0,0 @@
-wasmfs!
diff --git a/tests/test_core.py b/tests/test_core.py
index a09cbc107a09a..c5e690cfb35c6 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -141,7 +141,11 @@ def can_do_standalone(self):
 
 def also_with_wasmfs(func):
   def decorated(self):
+    self.set_setting('WASMFS', 0)
+    func(self)
+    print('wasmfs')
     self.set_setting('WASMFS')
+    func(self)
   return decorated
 
 
@@ -314,16 +318,12 @@ def get_bullet_library(self, use_cmake):
                             cache_name_extra=configure_commands[0])
 
   @also_with_standalone_wasm()
+  @also_with_wasmfs
   def test_hello_world(self):
     self.do_core_test('test_hello_world.c')
     # must not emit this unneeded internal thing
     self.assertNotContained('EMSCRIPTEN_GENERATED_FUNCTIONS', read_file('test_hello_world.js'))
 
-  @also_with_wasmfs
-  def test_wasmfs_hello_world(self):
-    self.do_core_test('test_wasmfs_hello_world.c')
-    self.assertNotContained('EMSCRIPTEN_GENERATED_FUNCTIONS', read_file('test_wasmfs_hello_world.js'))
-
   def test_wasm_synchronous_compilation(self):
     self.set_setting('STRICT_JS')
     self.set_setting('WASM_ASYNC_COMPILATION', 0)

From 9d4bdabd3b943d7883316ad602dfce4ced83c542 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 01:48:12 -0400
Subject: [PATCH 12/20] extracted writing to stdout to library_wasmfs.js

---
 emcc.py                      |  2 +-
 src/library_wasmfs.js        | 19 +++++++++++++++++++
 src/modules.js               |  2 ++
 system/lib/wasmfs/wasmfs.cpp | 34 ++++++++++------------------------
 4 files changed, 32 insertions(+), 25 deletions(-)
 create mode 100644 src/library_wasmfs.js

diff --git a/emcc.py b/emcc.py
index 9c6e02601b17e..1ed0e4801cc47 100755
--- a/emcc.py
+++ b/emcc.py
@@ -1771,7 +1771,7 @@ def default_setting(name, new_default):
     state.forced_stdlibs.append('libwasmfs')
     settings.FILESYSTEM = 0
     settings.SYSCALLS_REQUIRE_FILESYSTEM = 0
-    # settings.JS_LIBRARIES.append((0, 'library_wasmfs.js')) TODO: Add in future PR
+    settings.JS_LIBRARIES.append((0, 'library_wasmfs.js'))
 
   # Explicitly drop linking in a malloc implementation if program is not using any dynamic allocation calls.
   if not settings.USES_DYNAMIC_ALLOC:
diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
new file mode 100644
index 0000000000000..e5b4eb301507c
--- /dev/null
+++ b/src/library_wasmfs.js
@@ -0,0 +1,19 @@
+var WasmfsLibrary = {
+$WASMFS: {
+  buffers: [null, [], []], // 1 => stdout, 2 => stderr
+  printChar: function(stream, curr) {
+    if (curr === 0 || curr === 10) {
+      (stream === 1 ? out : err)(UTF8ArrayToString(WASMFS.buffers[stream], 0));
+      WASMFS.buffers[stream].length = 0;
+    } else {
+      WASMFS.buffers[stream].push(curr);
+    }
+    
+    return
+  },
+}
+}
+
+mergeInto(LibraryManager.library, WasmfsLibrary);
+
+DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push('$WASMFS');
diff --git a/src/modules.js b/src/modules.js
index a1167ba9bf44d..1d4433c71b0cf 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -110,6 +110,8 @@ var LibraryManager = {
         }
         libraries.push('library_noderawfs.js');
       }
+    } else {
+      libraries.push('library_wasmfs.js');
     }
 
     // Additional JS libraries (without AUTO_JS_LIBRARIES, link to these explicitly via -lxxx.js)
diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 4ee576af88134..671dedaea12fe 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -21,30 +21,16 @@ __wasi_errno_t __wasi_fd_write(
   // This will not not show in HTML, a console.warn in a worker is suffficient.
   // This would be a change from the current FS.
   if (fd == 1 || fd == 2) {
-    MAIN_THREAD_EM_ASM(
-      {
-        var buffer = [];
-        var fd = $0;
-        var iovs = $1;
-        var iovs_len = $2;
-        var nwritten = $3;
-        var num = 0;
-        for (var i = 0; i < iovs_len; i++) {
-          var ptr = HEAP32[iovs + i * 8 >> 2];
-          var len = HEAP32[iovs + i * 8 + 4 >> 2];
-          for (var j = 0; j < len; j++) {
-            if (HEAPU8[ptr + j] == 0 || HEAPU8[ptr + j] == 10) {
-              (fd == 1 ? out : err)(UTF8ArrayToString(buffer, 0));
-              buffer.length = 0;
-            } else {
-              buffer.push(HEAPU8[ptr + j]);
-            }
-          }
-          num += len;
-        }
-        HEAP32[nwritten >> 2] = num;
-      },
-      fd, iovs, iovs_len, nwritten);
+    __wasi_size_t num = 0;
+    for (size_t i = 0; i < iovs_len; i++) {
+      const uint8_t* ptr = iovs[i].buf;
+      __wasi_size_t len = iovs[i].buf_len;
+      for (__wasi_size_t j = 0; j < len; j++) {
+        EM_ASM({ WASMFS.printChar($0, HEAPU8[$1]); }, fd, ptr + j);
+      }
+      num += len;
+    }
+    *nwritten = num;
   }
   return 0;
 }

From 28bcfcbfac07dc849915cb2c345c89028ecd42aa Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 11:47:44 -0400
Subject: [PATCH 13/20] changed layout of library_wasmfs, removed EM_ASM

---
 src/library_wasmfs.js        | 24 +++++++++++-------------
 system/lib/wasmfs/wasmfs.cpp |  6 +++---
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
index e5b4eb301507c..58552698a044f 100644
--- a/src/library_wasmfs.js
+++ b/src/library_wasmfs.js
@@ -1,19 +1,17 @@
 var WasmfsLibrary = {
-$WASMFS: {
-  buffers: [null, [], []], // 1 => stdout, 2 => stderr
-  printChar: function(stream, curr) {
-    if (curr === 0 || curr === 10) {
-      (stream === 1 ? out : err)(UTF8ArrayToString(WASMFS.buffers[stream], 0));
-      WASMFS.buffers[stream].length = 0;
-    } else {
-      WASMFS.buffers[stream].push(curr);
+  $wasmfsBuffers: [null, [], []],
+  emscripten_wasmfs_printchar__deps: ['$wasmfsBuffers'],
+  emscripten_wasmfs_printchar: function(stream, ptr, len) {
+    for (var j = 0; j < len; j++) {
+      if (HEAPU8[ptr+j] === 0 || HEAPU8[ptr+j] === 10) {
+        (stream === 1 ? out : err)(UTF8ArrayToString(wasmfsBuffers[stream], 0));
+        wasmfsBuffers[stream].length = 0;
+      } else {
+        wasmfsBuffers[stream].push(HEAPU8[ptr+j]);
+      }
     }
     
-    return
-  },
-}
+  }
 }
 
 mergeInto(LibraryManager.library, WasmfsLibrary);
-
-DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push('$WASMFS');
diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 671dedaea12fe..66e2c4ae958bb 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -13,6 +13,8 @@
 
 extern "C" {
 
+int emscripten_wasmfs_printchar(__wasi_fd_t fd, const uint8_t* ptr, __wasi_size_t len);
+
 __wasi_errno_t __wasi_fd_write(
   __wasi_fd_t fd, const __wasi_ciovec_t* iovs, size_t iovs_len, __wasi_size_t* nwritten) {
   // FD 1 = STDOUT and FD 2 = STDERR.
@@ -25,9 +27,7 @@ __wasi_errno_t __wasi_fd_write(
     for (size_t i = 0; i < iovs_len; i++) {
       const uint8_t* ptr = iovs[i].buf;
       __wasi_size_t len = iovs[i].buf_len;
-      for (__wasi_size_t j = 0; j < len; j++) {
-        EM_ASM({ WASMFS.printChar($0, HEAPU8[$1]); }, fd, ptr + j);
-      }
+      emscripten_wasmfs_printchar(fd, ptr, len);
       num += len;
     }
     *nwritten = num;

From d31597ff03723ad1686d6e0322d107ac78358784 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 12:59:04 -0400
Subject: [PATCH 14/20] change name to _printbuffer

---
 src/library_wasmfs.js        | 4 ++--
 system/lib/wasmfs/wasmfs.cpp | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/library_wasmfs.js b/src/library_wasmfs.js
index 58552698a044f..0ae01069a8a47 100644
--- a/src/library_wasmfs.js
+++ b/src/library_wasmfs.js
@@ -1,7 +1,7 @@
 var WasmfsLibrary = {
   $wasmfsBuffers: [null, [], []],
-  emscripten_wasmfs_printchar__deps: ['$wasmfsBuffers'],
-  emscripten_wasmfs_printchar: function(stream, ptr, len) {
+  emscripten_wasmfs_printbuffer__deps: ['$wasmfsBuffers'],
+  emscripten_wasmfs_printbuffer: function(stream, ptr, len) {
     for (var j = 0; j < len; j++) {
       if (HEAPU8[ptr+j] === 0 || HEAPU8[ptr+j] === 10) {
         (stream === 1 ? out : err)(UTF8ArrayToString(wasmfsBuffers[stream], 0));
diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 66e2c4ae958bb..cc3dd5f6960ec 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -13,7 +13,7 @@
 
 extern "C" {
 
-int emscripten_wasmfs_printchar(__wasi_fd_t fd, const uint8_t* ptr, __wasi_size_t len);
+int emscripten_wasmfs_printbuffer(__wasi_fd_t fd, const uint8_t* ptr, __wasi_size_t len);
 
 __wasi_errno_t __wasi_fd_write(
   __wasi_fd_t fd, const __wasi_ciovec_t* iovs, size_t iovs_len, __wasi_size_t* nwritten) {
@@ -27,7 +27,7 @@ __wasi_errno_t __wasi_fd_write(
     for (size_t i = 0; i < iovs_len; i++) {
       const uint8_t* ptr = iovs[i].buf;
       __wasi_size_t len = iovs[i].buf_len;
-      emscripten_wasmfs_printchar(fd, ptr, len);
+      emscripten_wasmfs_printbuffer(fd, ptr, len);
       num += len;
     }
     *nwritten = num;

From 0ee2972b1ee0654bd8ee91d40243d8b752f8fc42 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 14:06:10 -0400
Subject: [PATCH 15/20] use emscripten_console_log

---
 system/lib/wasmfs/wasmfs.cpp | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index cc3dd5f6960ec..88a5cb21f8c20 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -37,21 +37,18 @@ __wasi_errno_t __wasi_fd_write(
 
 __wasi_errno_t __wasi_fd_seek(
   __wasi_fd_t fd, __wasi_filedelta_t offset, __wasi_whence_t whence, __wasi_filesize_t* newoffset) {
-  EM_ASM({out($0 + ' or __wasi_fd_seek has been temporarily stubbed and is inert')},
-    __PRETTY_FUNCTION__);
+  emscripten_console_log("__wasi_fd_seek has been temporarily stubbed and is inert");
   abort();
 }
 
 __wasi_errno_t __wasi_fd_close(__wasi_fd_t fd) {
-  EM_ASM({out($0 + ' or __wasi_fd_close has been temporarily stubbed and is inert')},
-    __PRETTY_FUNCTION__);
+  emscripten_console_log("__wasi_fd_close has been temporarily stubbed and is inert");
   abort();
 }
 
 __wasi_errno_t __wasi_fd_read(
   __wasi_fd_t fd, const __wasi_iovec_t* iovs, size_t iovs_len, __wasi_size_t* nread) {
-  EM_ASM({out($0 + ' or __wasi_fd_read has been temporarily stubbed and is inert')},
-    __PRETTY_FUNCTION__);
+  emscripten_console_log("__wasi_fd_read has been temporarily stubbed and is inert");
   abort();
 }
 }

From 47d4392c67f5458296e328396c107411837d75de Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 14:25:13 -0400
Subject: [PATCH 16/20] add html5.h header

---
 system/lib/wasmfs/wasmfs.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 88a5cb21f8c20..9610d5704d1d1 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -9,6 +9,7 @@
 #include <stdlib.h>
 #define __NEED_struct_iovec
 #include <emscripten/emscripten.h>
+#include <emscripten/html5.h>
 #include <wasi/api.h>
 
 extern "C" {

From 13ef89f08c5038cf1021485bf304f479329b2c23 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 16:25:44 -0400
Subject: [PATCH 17/20] removed errant #define, update test

---
 system/lib/wasmfs/wasmfs.cpp | 3 +--
 tests/test_core.py           | 2 ++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 9610d5704d1d1..5dfa7fb3fe167 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -6,10 +6,9 @@
 // // Current Status: Work in Progress.
 // // See https://github.com/emscripten-core/emscripten/issues/15041.
 
-#include <stdlib.h>
-#define __NEED_struct_iovec
 #include <emscripten/emscripten.h>
 #include <emscripten/html5.h>
+#include <stdlib.h>
 #include <wasi/api.h>
 
 extern "C" {
diff --git a/tests/test_core.py b/tests/test_core.py
index 14a09cf456d6f..670f0f4901ad4 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -144,6 +144,8 @@ def decorated(self):
     self.set_setting('WASMFS', 0)
     func(self)
     print('wasmfs')
+    if self.get_setting('STANDALONE_WASM'):
+      self.skipTest("test currently cannot run both with WASMFS and STANDALONE_WASM")
     self.set_setting('WASMFS')
     func(self)
   return decorated

From 8ce49c41a899773fa485f937d93acf02eedfe915 Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 17:36:50 -0400
Subject: [PATCH 18/20] edited tests, comments

---
 system/lib/wasmfs/wasmfs.cpp | 14 +++++++-------
 tests/test_core.py           |  1 -
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/system/lib/wasmfs/wasmfs.cpp b/system/lib/wasmfs/wasmfs.cpp
index 5dfa7fb3fe167..dc4e8e75e1bee 100644
--- a/system/lib/wasmfs/wasmfs.cpp
+++ b/system/lib/wasmfs/wasmfs.cpp
@@ -1,10 +1,10 @@
-// // Copyright 2021 The Emscripten Authors.  All rights reserved.
-// // Emscripten is available under two separate licenses, the MIT license and the
-// // University of Illinois/NCSA Open Source License.  Both these licenses can be
-// // found in the LICENSE file.
-// // wasmfs.cpp will implement a new file system that replaces the existing JS filesystem.
-// // Current Status: Work in Progress.
-// // See https://github.com/emscripten-core/emscripten/issues/15041.
+// Copyright 2021 The Emscripten Authors.  All rights reserved.
+// Emscripten is available under two separate licenses, the MIT license and the
+// University of Illinois/NCSA Open Source License.  Both these licenses can be
+// found in the LICENSE file.
+// wasmfs.cpp will implement a new file system that replaces the existing JS filesystem.
+// Current Status: Work in Progress.
+// See https://github.com/emscripten-core/emscripten/issues/15041.
 
 #include <emscripten/emscripten.h>
 #include <emscripten/html5.h>
diff --git a/tests/test_core.py b/tests/test_core.py
index 670f0f4901ad4..d99e02c18f1e4 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -141,7 +141,6 @@ def can_do_standalone(self):
 
 def also_with_wasmfs(func):
   def decorated(self):
-    self.set_setting('WASMFS', 0)
     func(self)
     print('wasmfs')
     if self.get_setting('STANDALONE_WASM'):

From d86d65590098bc2939659dc211fe5c278496958a Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 18:12:55 -0400
Subject: [PATCH 19/20] if WASMFS is off, do not link wasmfs.cpp

---
 tools/system_libs.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/system_libs.py b/tools/system_libs.py
index 3ce81fa7ca9a0..58175bf22db1a 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -1290,6 +1290,9 @@ class libwasmfs(MTLibrary):
 
   def get_files(self):
     return [utils.path_from_root('system/lib/wasmfs/wasmfs.cpp')]
+    
+  def can_build(self):
+    return settings.WASMFS
 
 
 class libhtml5(Library):

From d9936bf8aa443cded6b4895ddb5e7f893f76c9fe Mon Sep 17 00:00:00 2001
From: Ethan Lee <nathe.eel@gmail.com>
Date: Fri, 24 Sep 2021 18:43:26 -0400
Subject: [PATCH 20/20] remove whitespace

---
 tools/system_libs.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/system_libs.py b/tools/system_libs.py
index 58175bf22db1a..e354283f881a1 100644
--- a/tools/system_libs.py
+++ b/tools/system_libs.py
@@ -1290,7 +1290,7 @@ class libwasmfs(MTLibrary):
 
   def get_files(self):
     return [utils.path_from_root('system/lib/wasmfs/wasmfs.cpp')]
-    
+
   def can_build(self):
     return settings.WASMFS