Refactor __wasi_fd_write in wasmfs.cpp

emcc.py

@@ -1779,7 +1779,7 @@ 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: populate with library_wasmfs.js later
 
   # Explicitly drop linking in a malloc implementation if program is not using any dynamic allocation calls.
   if not settings.USES_DYNAMIC_ALLOC:

src/library_wasmfs.js

@@ -1,17 +1,3 @@
-var WasmfsLibrary = {
-  $wasmfsBuffers: [null, [], []],
-  emscripten_wasmfs_printbuffer__deps: ['$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));
-        wasmfsBuffers[stream].length = 0;
-      } else {
-        wasmfsBuffers[stream].push(HEAPU8[ptr+j]);
-      }
-    }
-
-  }
-}
+var WasmfsLibrary = {}
 
 mergeInto(LibraryManager.library, WasmfsLibrary);

src/modules.js

@@ -110,9 +110,8 @@ var LibraryManager = {
         }
         libraries.push('library_noderawfs.js');
       }
-    } else {
-      libraries.push('library_wasmfs.js');
-    }
+    } 
+    // TODO: populate with libraries.push('library_wasmfs.js') later
 
     // Additional JS libraries (without AUTO_JS_LIBRARIES, link to these explicitly via -lxxx.js)
     if (AUTO_JS_LIBRARIES) {

system/lib/wasmfs/wasmfs.cpp

@@ -9,25 +9,39 @@
 #include <emscripten/emscripten.h>
 #include <emscripten/html5.h>
 #include <stdlib.h>
+#include <vector>
 #include <wasi/api.h>
 
 extern "C" {
 
-int emscripten_wasmfs_printbuffer(__wasi_fd_t fd, const uint8_t* ptr, __wasi_size_t len);
+static std::vector<char> fd_write_stdstream_buffer;
 
 __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.
   // 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 will 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) {
     __wasi_size_t num = 0;
     for (size_t i = 0; i < iovs_len; i++) {
-      const uint8_t* ptr = iovs[i].buf;
+      const uint8_t* buf = iovs[i].buf;
       __wasi_size_t len = iovs[i].buf_len;
-      emscripten_wasmfs_printbuffer(fd, ptr, len);
+      for (__wasi_size_t j = 0; j < len; j++) {
+        uint8_t current = buf[j];
+        if (current == 0 || current == 10) {
+          fd_write_stdstream_buffer.push_back('\0'); // for null-terminated C strings
+          if (fd == 1) {
+            emscripten_console_log(&fd_write_stdstream_buffer[0]);
+          } else if (fd == 2) {
+            emscripten_console_error(&fd_write_stdstream_buffer[0]);
+          }
+          fd_write_stdstream_buffer.clear();
+        } else {
+          fd_write_stdstream_buffer.push_back(current);
+        }
+      }
       num += len;
     }
     *nwritten = num;

tests/common.py

@@ -551,7 +551,9 @@ def verify_es5(self, filename):
   def build(self, filename, libraries=[], includes=[], force_c=False, js_outfile=True, emcc_args=[], output_basename=None):
     suffix = '.js' if js_outfile else '.wasm'
     compiler = [compiler_for(filename, force_c)]
-    if compiler[0] == EMCC:
+    if compiler[0] == EMCC and not self.get_setting('WASMFS'):
+      # TODO change test behaviour in the future when WASMFS becomes default file system
+      # WASMFS is excluded here since it currently requires stdlib++ functions
       # TODO(https://github.com/emscripten-core/emscripten/issues/11121)
       # We link with C++ stdlibs, even when linking with emcc for historical reasons.  We can remove
       # this if this issues is fixed.