# Other subdirectories
SUBDIRSTOO= Include Lib Misc
-# assets for Emscripten browser builds
-WASM_ASSETS_DIR=.$(prefix)
-WASM_STDLIB=$(WASM_ASSETS_DIR)/lib/python$(VERSION)/os.py
-
# Files and directories to be distributed
CONFIGFILES= configure configure.ac acconfig.h pyconfig.h.in Makefile.pre.in
DISTFILES= README.rst ChangeLog $(CONFIGFILES)
build_wasm: check-clean-src $(BUILDPYTHON) platform sharedmods \
python-config checksharedmods
+.PHONY: build_emscripten
+build_emscripten: build_wasm web_example
+
# Check that the source is clean when building out of source.
.PHONY: check-clean-src
check-clean-src:
else true; \
fi
-# wasm32-emscripten browser build
-# wasm assets directory is relative to current build dir, e.g. "./usr/local".
-# --preload-file turns a relative asset path into an absolute path.
+# wasm32-emscripten browser web example
+
+WEBEX_DIR=$(srcdir)/Tools/wasm/emscripten/web_example/
+web_example/python.html: $(WEBEX_DIR)/python.html
+ @mkdir -p web_example
+ @cp $< $@
+
+web_example/python.worker.mjs: $(WEBEX_DIR)/python.worker.mjs
+ @mkdir -p web_example
+ @cp $< $@
-.PHONY: wasm_stdlib
-wasm_stdlib: $(WASM_STDLIB)
-$(WASM_STDLIB): $(srcdir)/Lib/*.py $(srcdir)/Lib/*/*.py \
- $(srcdir)/Tools/wasm/wasm_assets.py \
+web_example/server.py: $(WEBEX_DIR)/server.py
+ @mkdir -p web_example
+ @cp $< $@
+
+WEB_STDLIB=web_example/python$(VERSION)$(ABI_THREAD).zip
+$(WEB_STDLIB): $(srcdir)/Lib/*.py $(srcdir)/Lib/*/*.py \
+ $(WEBEX_DIR)/wasm_assets.py \
Makefile pybuilddir.txt Modules/Setup.local
- $(PYTHON_FOR_BUILD) $(srcdir)/Tools/wasm/wasm_assets.py \
- --buildroot . --prefix $(prefix)
+ $(PYTHON_FOR_BUILD) $(WEBEX_DIR)/wasm_assets.py \
+ --buildroot . --prefix $(prefix) -o $@
-python.html: $(srcdir)/Tools/wasm/python.html python.worker.js
- @cp $(srcdir)/Tools/wasm/python.html $@
+web_example/python.mjs web_example/python.wasm: $(BUILDPYTHON)
+ @if test $(HOST_GNU_TYPE) != 'wasm32-unknown-emscripten' ; then \
+ echo "Can only build web_example when target is Emscripten" ;\
+ exit 1 ;\
+ fi
+ cp python.mjs web_example/python.mjs
+ cp python.wasm web_example/python.wasm
-python.worker.js: $(srcdir)/Tools/wasm/python.worker.js
- @cp $(srcdir)/Tools/wasm/python.worker.js $@
+.PHONY: web_example
+web_example: web_example/python.mjs web_example/python.worker.mjs web_example/python.html web_example/server.py $(WEB_STDLIB)
############################################################################
# Header files
find build -name '*.py[co]' -exec rm -f {} ';' || true
-rm -f pybuilddir.txt
-rm -f _bootstrap_python
- -rm -f python.html python*.js python.data python*.symbols python*.map
- -rm -f $(WASM_STDLIB)
+ -rm -rf web_example python.mjs python.wasm python*.symbols python*.map
-rm -f Programs/_testembed Programs/_freeze_module
-rm -rf Python/deepfreeze
-rm -f Python/frozen_modules/*.h
--- /dev/null
+Updated the Emscripten web example to use ES6 modules and be built into a
+distinct ``web_example`` subfolder.
To cross compile to the ``wasm32-emscripten`` platform you need
[the Emscripten compiler toolchain](https://emscripten.org/),
-a Python interpreter, and an installation of Node version 18 or newer. Emscripten
-version 3.1.42 or newer is recommended. All commands below are relative to a checkout
-of the Python repository.
+a Python interpreter, and an installation of Node version 18 or newer.
+Emscripten version 3.1.73 or newer is recommended. All commands below are
+relative to a checkout of the Python repository.
#### Install [the Emscripten compiler toolchain](https://emscripten.org/docs/getting_started/downloads.html)
export EM_COMPILER_WRAPPER=ccache
```
-### Compile and build Python interpreter
+#### Compile and build Python interpreter
You can use `python Tools/wasm/emscripten` to compile and build targetting
Emscripten. You can do everything at once with:
python Tools/wasm/emscripten build --with-py-debug
```
+### Running from node
+
+If you want to run the normal Python CLI, you can use `python.sh`. It takes the
+same options as the normal Python CLI entrypoint, though the REPL does not
+function and will crash.
+
+`python.sh` invokes `node_entry.mjs` which imports the Emscripten module for the
+Python process and starts it up with the appropriate settings. If you wish to
+make a node application that "embeds" the interpreter instead of acting like the
+CLI you will need to write your own alternative to `node_entry.mjs`.
+
+
+### The Web Example
+
+When building for Emscripten, the web example will be built automatically. It is
+in the ``web_example`` directory. To run the web example, ``cd`` into the
+``web_example`` directory, then run ``python server.py``. This will start a web
+server; you can then visit ``http://localhost:8000/python.html`` in a browser to
+see a simple REPL example.
+
+The web example relies on a bug fix in Emscripten version 3.1.73 so if you build
+with earlier versions of Emscripten it may not work. The web example uses
+``SharedArrayBuffer``. For security reasons browsers only provide
+``SharedArrayBuffer`` in secure environments with cross-origin isolation. The
+webserver must send cross-origin headers and correct MIME types for the
+JavaScript and WebAssembly files. Otherwise the terminal will fail to load with
+an error message like ``ReferenceError: SharedArrayBuffer is not defined``. See
+more information here:
+https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer#security_requirements
+
+Note that ``SharedArrayBuffer`` is _not required_ to use Python itself, only the
+web example. If cross-origin isolation is not appropriate for your use case you
+may make your own application embedding `python.mjs` which does not use
+``SharedArrayBuffer`` and serve it without the cross-origin isolation headers.
+
+### Embedding Python in a custom JavaScript application
+
+You can look at `python.worker.mjs` and `node_entry.mjs` for inspiration. At a
+minimum you must import ``createEmscriptenModule`` and you need to call
+``createEmscriptenModule`` with an appropriate settings object. This settings
+object will need a prerun hook that installs the Python standard library into
+the Emscripten file system.
+
+#### NodeJs
+
+In Node, you can use the NodeFS to mount the standard library in your native
+file system into the Emscripten file system:
+```js
+import createEmscriptenModule from "./python.mjs";
+
+await createEmscriptenModule({
+ preRun(Module) {
+ Module.FS.mount(
+ Module.FS.filesystems.NODEFS,
+ { root: "/path/to/python/stdlib" },
+ "/lib/",
+ );
+ },
+});
+```
+
+#### Browser
+
+In the browser, the simplest approach is to put the standard library in a zip
+file it and install it. With Python 3.14 this could look like:
+```js
+import createEmscriptenModule from "./python.mjs";
+
+await createEmscriptenModule({
+ async preRun(Module) {
+ Module.FS.mkdirTree("/lib/python3.14/lib-dynload/");
+ Module.addRunDependency("install-stdlib");
+ const resp = await fetch("python3.14.zip");
+ const stdlibBuffer = await resp.arrayBuffer();
+ Module.FS.writeFile(`/lib/python314.zip`, new Uint8Array(stdlibBuffer), {
+ canOwn: true,
+ });
+ Module.removeRunDependency("install-stdlib");
+ },
+});
+```
+
### Limitations and issues
#### Network stack
- Test modules are disabled by default. Use ``--enable-test-modules`` build
test modules like ``_testcapi``.
-### wasm32-emscripten in node
-
-Node builds use ``NODERAWFS``.
-
-- Node RawFS allows direct access to the host file system without need to
- perform ``FS.mount()`` call.
-
-### Hosting Python WASM builds
-
-The simple REPL terminal uses SharedArrayBuffer. For security reasons
-browsers only provide the feature in secure environments with cross-origin
-isolation. The webserver must send cross-origin headers and correct MIME types
-for the JavaScript and WASM files. Otherwise the terminal will fail to load
-with an error message like ``Browsers disable shared array buffer``.
-
-#### Apache HTTP .htaccess
-
-Place a ``.htaccess`` file in the same directory as ``python.wasm``.
-
-```
-# .htaccess
-Header set Cross-Origin-Opener-Policy same-origin
-Header set Cross-Origin-Embedder-Policy require-corp
-
-AddType application/javascript js
-AddType application/wasm wasm
-
-<IfModule mod_deflate.c>
- AddOutputFilterByType DEFLATE text/html application/javascript application/wasm
-</IfModule>
-```
-
## WASI (wasm32-wasi)
See [the devguide on how to build and run for WASI](https://devguide.python.org/getting-started/setup-building/#wasi).
async initialiseWorker() {
if (!this.worker) {
- this.worker = new Worker(this.workerURL)
+ this.worker = new Worker(this.workerURL, {type: "module"})
this.worker.addEventListener('message', this.handleMessageFromWorker)
}
}
programRunning(false)
}
- const pythonWorkerManager = new WorkerManager('./python.worker.js', stdio, readyCallback, finishedCallback)
+ const pythonWorkerManager = new WorkerManager('./python.worker.mjs', stdio, readyCallback, finishedCallback)
}
</script>
</head>
+import createEmscriptenModule from "./python.mjs";
+
class StdinBuffer {
constructor() {
this.sab = new SharedArrayBuffer(128 * Int32Array.BYTES_PER_ELEMENT)
const stdinBuffer = new StdinBuffer()
-var Module = {
+const emscriptenSettings = {
noInitialRun: true,
stdin: stdinBuffer.stdin,
stdout: stdout,
stderr: stderr,
onRuntimeInitialized: () => {
postMessage({type: 'ready', stdinBuffer: stdinBuffer.sab})
+ },
+ async preRun(Module) {
+ const versionHex = Module.HEAPU32[Module._Py_Version/4].toString(16);
+ const versionTuple = versionHex.padStart(8, "0").match(/.{1,2}/g).map((x) => parseInt(x, 16));
+ const [major, minor, ..._] = versionTuple;
+ // Prevent complaints about not finding exec-prefix by making a lib-dynload directory
+ Module.FS.mkdirTree(`/lib/python${major}.${minor}/lib-dynload/`);
+ Module.addRunDependency("install-stdlib");
+ const resp = await fetch(`python${major}.${minor}.zip`);
+ const stdlibBuffer = await resp.arrayBuffer();
+ Module.FS.writeFile(`/lib/python${major}${minor}.zip`, new Uint8Array(stdlibBuffer), { canOwn: true });
+ Module.removeRunDependency("install-stdlib");
}
}
-onmessage = (event) => {
+const modulePromise = createEmscriptenModule(emscriptenSettings);
+
+
+onmessage = async (event) => {
if (event.data.type === 'run') {
+ const Module = await modulePromise;
if (event.data.files) {
for (const [filename, contents] of Object.entries(event.data.files)) {
Module.FS.writeFile(filename, contents)
}
}
- const ret = callMain(event.data.args)
+ const ret = Module.callMain(event.data.args);
postMessage({
type: 'finished',
returnCode: ret
}
}
-importScripts('python.js')
class MyHTTPRequestHandler(server.SimpleHTTPRequestHandler):
- extensions_map = server.SimpleHTTPRequestHandler.extensions_map.copy()
- extensions_map.update(
- {
- ".wasm": "application/wasm",
- }
- )
-
def end_headers(self) -> None:
self.send_my_headers()
super().end_headers()
bind=args.bind,
)
+
if __name__ == "__main__":
main()
from typing import Dict
# source directory
-SRCDIR = pathlib.Path(__file__).parent.parent.parent.absolute()
+SRCDIR = pathlib.Path(__file__).parents[4].absolute()
SRCDIR_LIB = SRCDIR / "Lib"
WASM_STDLIB_ZIP = (
WASM_LIB / f"python{sys.version_info.major}{sys.version_info.minor}.zip"
)
-WASM_STDLIB = (
- WASM_LIB / f"python{sys.version_info.major}.{sys.version_info.minor}"
-)
+WASM_STDLIB = WASM_LIB / f"python{sys.version_info.major}.{sys.version_info.minor}"
WASM_DYNLOAD = WASM_STDLIB / "lib-dynload"
assert isinstance(args.builddir, pathlib.Path)
data_name: str = sysconfig._get_sysconfigdata_name() # type: ignore[attr-defined]
if not data_name.startswith(SYSCONFIG_NAMES):
- raise ValueError(
- f"Invalid sysconfig data name '{data_name}'.", SYSCONFIG_NAMES
- )
+ raise ValueError(f"Invalid sysconfig data name '{data_name}'.", SYSCONFIG_NAMES)
filename = data_name + ".py"
return args.builddir / filename
return pathname not in args.omit_files_absolute
with zipfile.PyZipFile(
- args.wasm_stdlib_zip,
+ args.output,
mode="w",
compression=args.compression,
optimize=optimize,
default=pathlib.Path("/usr/local"),
type=path,
)
+parser.add_argument(
+ "-o",
+ "--output",
+ help="output file",
+ type=path,
+)
def main() -> None:
args.srcdir = SRCDIR
args.srcdir_lib = SRCDIR_LIB
args.wasm_root = args.buildroot / relative_prefix
- args.wasm_stdlib_zip = args.wasm_root / WASM_STDLIB_ZIP
args.wasm_stdlib = args.wasm_root / WASM_STDLIB
args.wasm_dynload = args.wasm_root / WASM_DYNLOAD
args.wasm_dynload.mkdir(parents=True, exist_ok=True)
marker = args.wasm_dynload / ".empty"
marker.touch()
- # os.py is a marker for finding the correct lib directory.
- shutil.copy(args.srcdir_lib / "os.py", args.wasm_stdlib)
# The rest of stdlib that's useful in a WASM context.
create_stdlib_zip(args)
- size = round(args.wasm_stdlib_zip.stat().st_size / 1024**2, 2)
- parser.exit(0, f"Created {args.wasm_stdlib_zip} ({size} MiB)\n")
+ size = round(args.output.stat().st_size / 1024**2, 2)
+ parser.exit(0, f"Created {args.output} ({size} MiB)\n")
if __name__ == "__main__":
fi
-elif test "$ac_sys_system" = "Emscripten" -o "$ac_sys_system" = "WASI"; then
- DEF_MAKE_ALL_RULE="build_wasm"
+elif test "$ac_sys_system" = "Emscripten"; then
+ DEF_MAKE_ALL_RULE="build_emscripten"
+ REQUIRE_PGO="no"
+ DEF_MAKE_RULE="all"
+elif test "$ac_sys_system" = "WASI"; then
+ DEF_MAKE_ALL_RULE="build_wasm"
REQUIRE_PGO="no"
DEF_MAKE_RULE="all"
else
wasm_debug=no
fi
- as_fn_append LDFLAGS_NODIST " -sALLOW_MEMORY_GROWTH -sTOTAL_MEMORY=20971520"
+ as_fn_append LDFLAGS_NODIST " -sALLOW_MEMORY_GROWTH -sINITIAL_MEMORY=20971520"
as_fn_append LDFLAGS_NODIST " -sWASM_BIGINT"
as_fn_append LDFLAGS_NODIST " -sFORCE_FILESYSTEM -lidbfs.js -lnodefs.js -lproxyfs.js -lworkerfs.js"
- as_fn_append LDFLAGS_NODIST " -sEXPORTED_RUNTIME_METHODS=FS"
+ as_fn_append LDFLAGS_NODIST " -sEXPORTED_RUNTIME_METHODS=FS,callMain"
+ as_fn_append LDFLAGS_NODIST " -sEXPORTED_FUNCTIONS=_main,_Py_Version"
if test "x$enable_wasm_dynamic_linking" = xyes
then :
as_fn_append LINKFORSHARED " -sPROXY_TO_PTHREAD"
fi
- as_fn_append LDFLAGS_NODIST " -sALLOW_MEMORY_GROWTH"
as_fn_append LDFLAGS_NODIST " -sEXIT_RUNTIME"
WASM_LINKFORSHARED_DEBUG="-gseparate-dwarf --emit-symbol-map"
LDFLAGS_NODIST="$LDFLAGS_NODIST -fno-semantic-interposition"
], [], [-Werror])
])
-elif test "$ac_sys_system" = "Emscripten" -o "$ac_sys_system" = "WASI"; then
- dnl Emscripten does not support shared extensions yet. Build
- dnl "python.[js,wasm]", "pybuilddir.txt", and "platform" files.
+elif test "$ac_sys_system" = "Emscripten"; then
+ dnl Build "python.[js,wasm]", "pybuilddir.txt", and "platform" files.
+ DEF_MAKE_ALL_RULE="build_emscripten"
+ REQUIRE_PGO="no"
+ DEF_MAKE_RULE="all"
+elif test "$ac_sys_system" = "WASI"; then
+ dnl Build "python.wasm", "pybuilddir.txt", and "platform" files.
DEF_MAKE_ALL_RULE="build_wasm"
REQUIRE_PGO="no"
DEF_MAKE_RULE="all"
AS_VAR_IF([Py_DEBUG], [yes], [wasm_debug=yes], [wasm_debug=no])
dnl Start with 20 MB and allow to grow
- AS_VAR_APPEND([LDFLAGS_NODIST], [" -sALLOW_MEMORY_GROWTH -sTOTAL_MEMORY=20971520"])
+ AS_VAR_APPEND([LDFLAGS_NODIST], [" -sALLOW_MEMORY_GROWTH -sINITIAL_MEMORY=20971520"])
dnl map int64_t and uint64_t to JS bigint
AS_VAR_APPEND([LDFLAGS_NODIST], [" -sWASM_BIGINT"])
dnl Include file system support
AS_VAR_APPEND([LDFLAGS_NODIST], [" -sFORCE_FILESYSTEM -lidbfs.js -lnodefs.js -lproxyfs.js -lworkerfs.js"])
- AS_VAR_APPEND([LDFLAGS_NODIST], [" -sEXPORTED_RUNTIME_METHODS=FS"])
+ AS_VAR_APPEND([LDFLAGS_NODIST], [" -sEXPORTED_RUNTIME_METHODS=FS,callMain"])
+ AS_VAR_APPEND([LDFLAGS_NODIST], [" -sEXPORTED_FUNCTIONS=_main,_Py_Version"])
AS_VAR_IF([enable_wasm_dynamic_linking], [yes], [
AS_VAR_APPEND([LINKFORSHARED], [" -sMAIN_MODULE"])
AS_VAR_APPEND([LDFLAGS_NODIST], [" -sUSE_PTHREADS"])
AS_VAR_APPEND([LINKFORSHARED], [" -sPROXY_TO_PTHREAD"])
])
- AS_VAR_APPEND([LDFLAGS_NODIST], [" -sALLOW_MEMORY_GROWTH"])
dnl not completely sure whether or not we want -sEXIT_RUNTIME, keeping it for now.
AS_VAR_APPEND([LDFLAGS_NODIST], [" -sEXIT_RUNTIME"])
WASM_LINKFORSHARED_DEBUG="-gseparate-dwarf --emit-symbol-map"
projects / thirdparty / Python / cpython.git / commitdiff
