Merge pull request rustwasm#936 from alexcrichton/import-gc

Import the `wasm-gc-api` crate into this repository

Author: alexcrichton

crates/cli-support/Cargo.toml

@@ -19,4 +19,4 @@ serde_json = "1.0"
 tempfile = "3.0"
 wasm-bindgen-shared = { path = "../shared", version = '=0.2.24' }
 wasm-bindgen-wasm-interpreter = { path = "../wasm-interpreter", version = '=0.2.24' }
-wasm-gc-api = "0.1.9"
+wasm-bindgen-gc = { path = '../gc', version = '=0.2.24' }

crates/cli-support/src/js/mod.rs

@@ -3,10 +3,9 @@ use std::fmt::Write;
 use std::mem;
 
 use failure::{Error, ResultExt};
-use parity_wasm;
 use parity_wasm::elements::*;
 use shared;
-use wasm_gc;
+use wasm_bindgen_gc;
 
 use super::Bindgen;
 use descriptor::{Descriptor, VectorKind};
@@ -403,7 +402,7 @@ impl<'a> Context<'a> {
         self.create_memory_export();
         self.unexport_unused_internal_exports();
         closures::rewrite(self)?;
-        self.gc()?;
+        self.gc();
 
         // Note that it's important `throw` comes last *after* we gc. The
         // `__wbindgen_malloc` function may call this but we only want to
@@ -482,7 +481,7 @@ impl<'a> Context<'a> {
         };
 
         self.export_table();
-        self.gc()?;
+        self.gc();
 
         while js.contains("\n\n\n") {
             js = js.replace("\n\n\n", "\n\n");
@@ -1661,18 +1660,12 @@ impl<'a> Context<'a> {
         );
     }
 
-    fn gc(&mut self) -> Result<(), Error> {
+    fn gc(&mut self) {
         self.parse_wasm_names();
-        let module = mem::replace(self.module, Module::default());
-        let result = wasm_gc::Config::new()
+        wasm_bindgen_gc::Config::new()
             .demangle(self.config.demangle)
             .keep_debug(self.config.keep_debug || self.config.debug)
-            .run(module, |m| parity_wasm::serialize(m).unwrap())?;
-        *self.module = match result.into_module() {
-            Ok(m) => m,
-            Err(result) => deserialize_buffer(&result.into_bytes()?)?,
-        };
-        Ok(())
+            .run(&mut self.module);
     }
 
     fn parse_wasm_names(&mut self) {

crates/cli-support/src/lib.rs

@@ -3,7 +3,7 @@
 extern crate parity_wasm;
 extern crate serde_json;
 extern crate wasm_bindgen_shared as shared;
-extern crate wasm_gc;
+extern crate wasm_bindgen_gc;
 #[macro_use]
 extern crate failure;
 extern crate wasm_bindgen_wasm_interpreter as wasm_interpreter;

crates/gc/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "wasm-bindgen-gc"
+version = "0.2.24"
+authors = ["The wasm-bindgen Developers"]
+license = "MIT/Apache-2.0"
+repository = "https://github.com/rustwasm/wasm-bindgen/tree/master/crates/gc"
+homepage = "https://rustwasm.github.io/wasm-bindgen/"
+documentation = "https://docs.rs/wasm-bindgen-gc"
+description = """
+Support for removing unused items from a wasm executable
+"""
+
+[dependencies]
+parity-wasm = "0.32"
+log = "0.4"
+rustc-demangle = "0.1.9"

crates/gc/src/bitvec.rs

@@ -0,0 +1,66 @@
+use std::mem;
+
+type T = usize;
+
+const BITS: usize = mem::size_of::<T>() * 8;
+
+pub struct BitSet {
+    bits: Vec<T>,
+}
+
+impl BitSet {
+    pub fn new() -> BitSet {
+        BitSet { bits: Vec::new() }
+    }
+
+    pub fn insert(&mut self, i: u32) -> bool {
+        let i = i as usize;
+        let idx = i / BITS;
+        let bit = 1 << (i % BITS);
+        if self.bits.len() <= idx {
+            self.bits.resize(idx + 1, 0);
+        }
+        let slot = &mut self.bits[idx];
+        if *slot & bit != 0 {
+            false
+        } else {
+            *slot |= bit;
+            true
+        }
+    }
+
+    pub fn contains(&self, i: &u32) -> bool {
+        let i = *i as usize;
+        let idx = i / BITS;
+        let bit = 1 << (i % BITS);
+        self.bits.get(idx)
+            .map(|x| *x & bit != 0)
+            .unwrap_or(false)
+    }
+}
+
+impl Default for BitSet {
+    fn default() -> BitSet {
+        BitSet::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::BitSet;
+
+    #[test]
+    fn simple() {
+        let mut x = BitSet::new();
+        assert!(!x.contains(&1));
+        assert!(!x.contains(&0));
+        assert!(!x.contains(&3));
+        assert!(x.insert(3));
+        assert!(x.contains(&3));
+        assert!(!x.insert(3));
+        assert!(x.contains(&3));
+        assert!(!x.contains(&1));
+        assert!(x.insert(2));
+        assert!(x.contains(&2));
+    }
+}