From d521554e5b5abf4209abf0f61d7297aef5ce5b3c Mon Sep 17 00:00:00 2001
From: Karthik Ganeshram <karthik.ganeshram@fermyon.com>
Date: Thu, 30 May 2024 20:28:15 +0200
Subject: [PATCH] do not stub imports that are part of the target world (#109)

---
 .../spidermonkey-embedding-splicer/src/lib.rs |   10 +-
 .../src/stub_wasi.rs                          | 1300 +++++++++--------
 .../wit/spidermonkey-embedding-splicer.wit    |    2 +-
 src/componentize.js                           |    6 +-
 4 files changed, 714 insertions(+), 604 deletions(-)

diff --git a/crates/spidermonkey-embedding-splicer/src/lib.rs b/crates/spidermonkey-embedding-splicer/src/lib.rs
index bf79dce..390cc72 100644
--- a/crates/spidermonkey-embedding-splicer/src/lib.rs
+++ b/crates/spidermonkey-embedding-splicer/src/lib.rs
@@ -94,8 +94,14 @@ fn parse_wit(path: &Path) -> Result<(Resolve, PackageId)> {
 }
 
 impl Guest for SpidermonkeyEmbeddingSplicerComponent {
-    fn stub_wasi(wasm: Vec<u8>, features: Vec<Features>) -> Result<Vec<u8>, String> {
-        stub_wasi(wasm, features).map_err(|e| e.to_string())
+    fn stub_wasi(
+        wasm: Vec<u8>,
+        features: Vec<Features>,
+        wit_source: Option<String>,
+        wit_path: Option<String>,
+        world_name: Option<String>,
+    ) -> Result<Vec<u8>, String> {
+        stub_wasi(wasm, features, wit_source, wit_path, world_name).map_err(|e| e.to_string())
     }
 
     fn splice_bindings(
diff --git a/crates/spidermonkey-embedding-splicer/src/stub_wasi.rs b/crates/spidermonkey-embedding-splicer/src/stub_wasi.rs
index 0f813c0..9760232 100644
--- a/crates/spidermonkey-embedding-splicer/src/stub_wasi.rs
+++ b/crates/spidermonkey-embedding-splicer/src/stub_wasi.rs
@@ -1,12 +1,17 @@
 use anyhow::{bail, Result};
-use std::time::{SystemTime, UNIX_EPOCH};
+use std::{
+    collections::HashSet,
+    path::PathBuf,
+    time::{SystemTime, UNIX_EPOCH},
+};
 use walrus::{
     ir::{BinaryOp, MemArg, StoreKind, UnaryOp},
     Function, FunctionBuilder, FunctionId, FunctionKind, ImportKind, ImportedFunction, InitExpr,
     InstrSeqBuilder, LocalId, Module, ValType,
 };
+use wit_parser::{Resolve, UnresolvedPackage};
 
-use crate::Features;
+use crate::{parse_wit, Features};
 
 fn stub_import<StubFn>(
     module: &mut Module,
@@ -52,12 +57,40 @@ fn unreachable_stub(body: &mut InstrSeqBuilder) -> Result<Vec<LocalId>> {
     Ok(vec![])
 }
 
-pub fn stub_wasi(wasm: Vec<u8>, features: Vec<Features>) -> Result<Vec<u8>> {
+pub fn stub_wasi(
+    wasm: Vec<u8>,
+    features: Vec<Features>,
+    wit_source: Option<String>,
+    wit_path: Option<String>,
+    world_name: Option<String>,
+) -> Result<Vec<u8>> {
+    let (resolve, id) = if let Some(wit_source) = wit_source {
+        let mut resolve = Resolve::default();
+        let path = PathBuf::from("component.wit");
+        let pkg = UnresolvedPackage::parse(&path, &wit_source)?;
+
+        let id = resolve.push(pkg)?;
+
+        (resolve, id)
+    } else {
+        parse_wit(&PathBuf::from(wit_path.unwrap()))?
+    };
+
+    let world = resolve.select_world(id, world_name.as_deref())?;
+
+    let target_world = &resolve.worlds[world];
+    let mut target_world_imports = HashSet::new();
+
+    for (key, _) in &target_world.imports {
+        target_world_imports.insert(resolve.name_world_key(key));
+    }
+
     let mut module = Module::from_buffer(wasm.as_slice())?;
 
     stub_preview1(&mut module)?;
-    stub_filesystem(&mut module)?;
-    stub_cli(&mut module)?;
+
+    stub_filesystem(&mut module, &target_world_imports)?;
+    stub_cli(&mut module, &target_world_imports)?;
 
     if !features.contains(&Features::Random) {
         stub_random(&mut module)?;
@@ -77,16 +110,34 @@ pub fn stub_wasi(wasm: Vec<u8>, features: Vec<Features>) -> Result<Vec<u8>> {
 
     let has_io = features.contains(&Features::Clocks)
         || features.contains(&Features::Stdio)
-        || features.contains(&Features::Http);
+        || features.contains(&Features::Http)
+        || target_world_requires_io(&target_world_imports);
     if !has_io {
         stub_io(&mut module)?;
     }
 
-    stub_sockets(&mut module)?;
+    stub_sockets(&mut module, &target_world_imports)?;
 
     Ok(module.emit_wasm())
 }
 
+fn target_world_requires_io(target_world_imports: &HashSet<String>) -> bool {
+    return target_world_imports.contains("wasi:sockets/instance-network@0.2.0")
+        || target_world_imports.contains("wasi:sockets/udp@0.2.0")
+        || target_world_imports.contains("wasi:sockets/udp-create-socket@0.2.0")
+        || target_world_imports.contains("wasi:sockets/tcp@0.2.0")
+        || target_world_imports.contains("wasi:sockets/tcp-create-socket@0.2.0")
+        || target_world_imports.contains("wasi:sockets/ip-name-lookup@0.2.0")
+        || target_world_imports.contains("wasi:sockets/network@0.2.0")
+        || target_world_imports.contains("wasi:filesystem/types@0.2.0")
+        || target_world_imports.contains("wasi:filesystem/preopens@0.2.0")
+        || target_world_imports.contains("wasi:cli/terminal-stdin@0.2.0")
+        || target_world_imports.contains("wasi:cli/terminal-stdout@0.2.0")
+        || target_world_imports.contains("wasi:cli/terminal-stderr@0.2.0")
+        || target_world_imports.contains("wasi:cli/terminal-input@0.2.0")
+        || target_world_imports.contains("wasi:cli/terminal-output@0.2.0");
+}
+
 const PREVIEW1: &str = "wasi_snapshot_preview1";
 fn stub_preview1(module: &mut Module) -> Result<()> {
     stub_import(module, PREVIEW1, "environ_get", unreachable_stub)?;
@@ -866,603 +917,654 @@ fn stub_io(module: &mut Module) -> Result<()> {
     Ok(())
 }
 
-fn stub_sockets(module: &mut Module) -> Result<()> {
-    stub_import(
-        module,
-        "wasi:sockets/instance-network@0.2.0",
-        "instance-network",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.start-bind",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.finish-bind",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.local-address",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.remote-address",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.address-family",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.unicast-hop-limit",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.set-unicast-hop-limit",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.receive-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.set-receive-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.send-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.set-send-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]udp-socket.subscribe",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]incoming-datagram-stream.receive",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]incoming-datagram-stream.subscribe",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]outgoing-datagram-stream.check-send",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]outgoing-datagram-stream.send",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[method]outgoing-datagram-stream.subscribe",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp-create-socket@0.2.0",
-        "create-udp-socket",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.start-bind",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.finish-bind",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.start-connect",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.finish-connect",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.start-listen",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.finish-listen",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.accept",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.local-address",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.remote-address",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.is-listening",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.address-family",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-listen-backlog-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.keep-alive-enabled",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-keep-alive-enabled",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.keep-alive-idle-time",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-keep-alive-idle-time",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.keep-alive-interval",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-keep-alive-interval",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.keep-alive-count",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-keep-alive-count",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.hop-limit",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-hop-limit",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.receive-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-receive-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.send-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.set-send-buffer-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.subscribe",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[method]tcp-socket.shutdown",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp-create-socket@0.2.0",
-        "create-tcp-socket",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/ip-name-lookup@0.2.0",
-        "resolve-addresses",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/ip-name-lookup@0.2.0",
-        "[method]resolve-address-stream.resolve-next-address",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/ip-name-lookup@0.2.0",
-        "[method]resolve-address-stream.subscribe",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/network@0.2.0",
-        "[resource-drop]network",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[resource-drop]udp-socket",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[resource-drop]incoming-datagram-stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/udp@0.2.0",
-        "[resource-drop]outgoing-datagram-stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/tcp@0.2.0",
-        "[resource-drop]tcp-socket",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:sockets/ip-name-lookup@0.2.0",
-        "[resource-drop]resolve-address-stream",
-        unreachable_stub,
-    )?;
+fn stub_sockets(module: &mut Module, world_imports: &HashSet<String>) -> Result<()> {
+    if !world_imports.contains("wasi:sockets/instance-network@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/instance-network@0.2.0",
+            "instance-network",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/udp@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.start-bind",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.finish-bind",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.stream",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.local-address",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.remote-address",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.address-family",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.unicast-hop-limit",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.set-unicast-hop-limit",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.receive-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.set-receive-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.send-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.set-send-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]udp-socket.subscribe",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]incoming-datagram-stream.receive",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]incoming-datagram-stream.subscribe",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]outgoing-datagram-stream.check-send",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]outgoing-datagram-stream.send",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[method]outgoing-datagram-stream.subscribe",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[resource-drop]udp-socket",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[resource-drop]incoming-datagram-stream",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/udp@0.2.0",
+            "[resource-drop]outgoing-datagram-stream",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/udp-create-socket@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/udp-create-socket@0.2.0",
+            "create-udp-socket",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/tcp@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.start-bind",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.finish-bind",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.start-connect",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.finish-connect",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.start-listen",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.finish-listen",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.accept",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.local-address",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.remote-address",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.is-listening",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.address-family",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-listen-backlog-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.keep-alive-enabled",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-keep-alive-enabled",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.keep-alive-idle-time",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-keep-alive-idle-time",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.keep-alive-interval",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-keep-alive-interval",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.keep-alive-count",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-keep-alive-count",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.hop-limit",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-hop-limit",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.receive-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-receive-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.send-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.set-send-buffer-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.subscribe",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[method]tcp-socket.shutdown",
+            unreachable_stub,
+        )?;
+
+        stub_import(
+            module,
+            "wasi:sockets/tcp@0.2.0",
+            "[resource-drop]tcp-socket",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/tcp-create-socket@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/tcp-create-socket@0.2.0",
+            "create-tcp-socket",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/ip-name-lookup@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/ip-name-lookup@0.2.0",
+            "resolve-addresses",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/ip-name-lookup@0.2.0",
+            "[method]resolve-address-stream.resolve-next-address",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:sockets/ip-name-lookup@0.2.0",
+            "[method]resolve-address-stream.subscribe",
+            unreachable_stub,
+        )?;
+
+        stub_import(
+            module,
+            "wasi:sockets/ip-name-lookup@0.2.0",
+            "[resource-drop]resolve-address-stream",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:sockets/network@0.2.0") {
+        stub_import(
+            module,
+            "wasi:sockets/network@0.2.0",
+            "[resource-drop]network",
+            unreachable_stub,
+        )?;
+    }
+
     Ok(())
 }
 
-fn stub_filesystem(module: &mut Module) -> Result<()> {
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "filesystem-error-code",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.read-via-stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.write-via-stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.append-via-stream",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.advise",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.sync-data",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.get-flags",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.get-type",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.set-size",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.set-times",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.read",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.write",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.sync",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.create-directory-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.stat",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.stat-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.set-times-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.link-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.open-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.readlink-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.remove-directory-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.rename-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.symlink-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.unlink-file-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.is-same-object",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.metadata-hash",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.metadata-hash-at",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]directory-entry-stream.read-directory-entry",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[method]descriptor.read-directory",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[resource-drop]descriptor",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/preopens@0.2.0",
-        "get-directories",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:filesystem/types@0.2.0",
-        "[resource-drop]directory-entry-stream",
-        unreachable_stub,
-    )?;
+fn stub_filesystem(module: &mut Module, world_imports: &HashSet<String>) -> Result<()> {
+    if !world_imports.contains("wasi:filesystem/types@0.2.0") {
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "filesystem-error-code",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.read-via-stream",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.write-via-stream",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.append-via-stream",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.advise",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.sync-data",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.get-flags",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.get-type",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.set-size",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.set-times",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.read",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.write",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.sync",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.create-directory-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.stat",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.stat-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.set-times-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.link-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.open-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.readlink-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.remove-directory-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.rename-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.symlink-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.unlink-file-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.is-same-object",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.metadata-hash",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.metadata-hash-at",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]directory-entry-stream.read-directory-entry",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[method]descriptor.read-directory",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[resource-drop]descriptor",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:filesystem/types@0.2.0",
+            "[resource-drop]directory-entry-stream",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:filesystem/preopens@0.2.0") {
+        stub_import(
+            module,
+            "wasi:filesystem/preopens@0.2.0",
+            "get-directories",
+            unreachable_stub,
+        )?;
+    }
+
     Ok(())
 }
 
-fn stub_cli(module: &mut Module) -> Result<()> {
-    stub_import(
-        module,
-        "wasi:cli/environment@0.2.0",
-        "get-environment",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/environment@0.2.0",
-        "get-arguments",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/environment@0.2.0",
-        "initial-cwd",
-        unreachable_stub,
-    )?;
-    stub_import(module, "wasi:cli/exit@0.2.0", "exit", unreachable_stub)?;
-    stub_import(
-        module,
-        "wasi:cli/terminal-stdin@0.2.0",
-        "get-terminal-stdin",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/terminal-stdout@0.2.0",
-        "get-terminal-stdout",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/terminal-stderr@0.2.0",
-        "get-terminal-stderr",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/terminal-input@0.2.0",
-        "[resource-drop]terminal-input",
-        unreachable_stub,
-    )?;
-    stub_import(
-        module,
-        "wasi:cli/terminal-output@0.2.0",
-        "[resource-drop]terminal-output",
-        unreachable_stub,
-    )?;
+fn stub_cli(module: &mut Module, world_imports: &HashSet<String>) -> Result<()> {
+    if !world_imports.contains("wasi:cli/environment@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/environment@0.2.0",
+            "get-environment",
+            unreachable_stub,
+        )?;
+
+        stub_import(
+            module,
+            "wasi:cli/environment@0.2.0",
+            "get-arguments",
+            unreachable_stub,
+        )?;
+        stub_import(
+            module,
+            "wasi:cli/environment@0.2.0",
+            "initial-cwd",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:cli/exit@0.2.0") {
+        stub_import(module, "wasi:cli/exit@0.2.0", "exit", unreachable_stub)?;
+    }
+
+    if !world_imports.contains("wasi:cli/terminal-stdin@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/terminal-stdin@0.2.0",
+            "get-terminal-stdin",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:cli/terminal-stdout@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/terminal-stdout@0.2.0",
+            "get-terminal-stdout",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:cli/terminal-stderr@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/terminal-stderr@0.2.0",
+            "get-terminal-stderr",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:cli/terminal-input@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/terminal-input@0.2.0",
+            "[resource-drop]terminal-input",
+            unreachable_stub,
+        )?;
+    }
+
+    if !world_imports.contains("wasi:cli/terminal-output@0.2.0") {
+        stub_import(
+            module,
+            "wasi:cli/terminal-output@0.2.0",
+            "[resource-drop]terminal-output",
+            unreachable_stub,
+        )?;
+    }
+
     Ok(())
 }
diff --git a/crates/spidermonkey-embedding-splicer/wit/spidermonkey-embedding-splicer.wit b/crates/spidermonkey-embedding-splicer/wit/spidermonkey-embedding-splicer.wit
index 7cde50e..08aa15d 100644
--- a/crates/spidermonkey-embedding-splicer/wit/spidermonkey-embedding-splicer.wit
+++ b/crates/spidermonkey-embedding-splicer/wit/spidermonkey-embedding-splicer.wit
@@ -31,7 +31,7 @@ world spidermonkey-embedding-splicer {
     imports: list<tuple<string, string, u32>>,
   }
 
-  export stub-wasi: func(engine: list<u8>, features: list<features>) -> result<list<u8>, string>;
+  export stub-wasi: func(engine: list<u8>, features: list<features>, wit-world: option<string>, wit-path: option<string>, world-name: option<string>) -> result<list<u8>, string>;
 
   export splice-bindings: func(source-name: option<string>, spidermonkey-engine: list<u8>, wit-world: option<string>, wit-path: option<string>, world-name: option<string>, debug: bool) -> result<splice-result, string>;
 }
diff --git a/src/componentize.js b/src/componentize.js
index d6ae941..52cba5b 100644
--- a/src/componentize.js
+++ b/src/componentize.js
@@ -24,7 +24,7 @@ const isWindows = platform === 'win32';
 const DEBUG_BINDINGS = false;
 const DEBUG_CALLS = false;
 
-function maybeWindowsPath (path) {
+function maybeWindowsPath(path) {
   if (!path) return path;
   if (!isWindows) return resolve(path);
   return '//?/' + resolve(path).replace(/\\/g, '/');
@@ -314,7 +314,9 @@ export async function componentize(jsSource, witWorld, opts) {
   }
 
   // after wizering, stub out the wasi imports depending on what features are enabled
-  const finalBin = stubWasi(bin, features);
+  const finalBin = stubWasi(bin, features, witWorld,
+    maybeWindowsPath(witPath),
+    worldName,);
 
   const component = await metadataAdd(
     await componentNew(