Merge pull request #1692 from alexcrichton/fix-anyref-bugs

Fix a number of `anyref` related bugs in our passes

Author: alexcrichton

crates/anyref-xform/src/lib.rs

@@ -254,10 +254,6 @@ impl Transform<'_> {
         // functions and make sure everything is still hooked up right.
         self.rewrite_calls(module);
 
-        // Inject initialization routine to set up default slots in the table
-        // (things like null/undefined/true/false)
-        self.inject_initialization(module);
-
         Ok(())
     }
 
@@ -514,14 +510,14 @@ impl Transform<'_> {
                     // Store an anyref at an offset from our function's stack
                     // pointer frame.
                     let get_fp = builder.local_get(fp);
-                    next_stack_offset += 1;
-                    let (index, idx_local) = if next_stack_offset == 1 {
+                    let (index, idx_local) = if next_stack_offset == 0 {
                         (get_fp, fp)
                     } else {
                         let rhs = builder.i32_const(next_stack_offset);
                         let add = builder.binop(BinaryOp::I32Add, get_fp, rhs);
                         (builder.local_tee(scratch_i32, add), scratch_i32)
                     };
+                    next_stack_offset += 1;
                     let store = builder.table_set(self.table, index, local);
                     let get = builder.local_get(idx_local);
                     builder.with_side_effects(vec![store], get, Vec::new())
@@ -669,31 +665,4 @@ impl Transform<'_> {
             }
         }
     }
-
-    // Ensure that the `start` function for this module calls the
-    // `__wbindgen_init_anyref_table` function. This'll ensure that all
-    // instances of this module have the initial slots of the anyref table
-    // initialized correctly.
-    fn inject_initialization(&mut self, module: &mut Module) {
-        let ty = module.types.add(&[], &[]);
-        let (import, _) = module.add_import_func(
-            "__wbindgen_placeholder__",
-            "__wbindgen_init_anyref_table",
-            ty,
-        );
-
-        let prev_start = match module.start {
-            Some(f) => f,
-            None => {
-                module.start = Some(import);
-                return;
-            }
-        };
-
-        let mut builder = walrus::FunctionBuilder::new();
-        let call_init = builder.call(import, Box::new([]));
-        let call_prev = builder.call(prev_start, Box::new([]));
-        let new_start = builder.finish(ty, Vec::new(), vec![call_init, call_prev], module);
-        module.start = Some(new_start);
-    }
 }

crates/cli-support/src/intrinsic.rs

@@ -145,7 +145,7 @@ intrinsics! {
         #[symbol = "__wbindgen_anyref_heap_live_count"]
         #[signature = fn() -> I32]
         AnyrefHeapLiveCount,
-        #[symbol = "__wbindgen_init_nyref_table"]
+        #[symbol = "__wbindgen_init_anyref_table"]
         #[signature = fn() -> Unit]
         InitAnyrefTable,
     }

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

@@ -194,10 +194,7 @@ impl<'a> Context<'a> {
         // up we always remove the `start` function if one is present. The JS
         // bindings glue then manually calls the start function (if it was
         // previously present).
-        let mut needs_manual_start = false;
-        if self.config.emit_start {
-            needs_manual_start = self.unstart_start_function();
-        }
+        let needs_manual_start = self.unstart_start_function();
 
         // After all we've done, especially
         // `unexport_unused_internal_exports()`, we probably have a bunch of
@@ -517,7 +514,10 @@ impl<'a> Context<'a> {
         for (i, extra) in extra_modules.iter().enumerate() {
             let imports = match &mut imports {
                 Some(list) => list,
-                None => bail!("cannot import from modules (`{}`) with `--no-modules`", extra),
+                None => bail!(
+                    "cannot import from modules (`{}`) with `--no-modules`",
+                    extra
+                ),
             };
             imports.push_str(&format!("import * as __wbg_star{} from '{}';\n", i, extra));
             imports_init.push_str(&format!("imports['{}'] = __wbg_star{};\n", extra, i));
@@ -2641,16 +2641,23 @@ impl<'a> Context<'a> {
 
             Intrinsic::InitAnyrefTable => {
                 self.expose_anyref_table();
-                String::from(
+
+                // Grow the table to insert our initial values, and then also
+                // set the 0th slot to `undefined` since that's what we've
+                // historically used for our ABI which is that the index of 0
+                // returns `undefined` for types like `None` going out.
+                let mut base = format!(
                     "
                       const table = wasm.__wbg_anyref_table;
-                      const offset = table.grow(4);
-                      table.set(offset + 0, undefined);
-                      table.set(offset + 1, null);
-                      table.set(offset + 2, true);
-                      table.set(offset + 3, false);
+                      const offset = table.grow({});
+                      table.set(0, undefined);
                     ",
-                )
+                    INITIAL_HEAP_VALUES.len(),
+                );
+                for (i, value) in INITIAL_HEAP_VALUES.iter().enumerate() {
+                    base.push_str(&format!("table.set(offset + {}, {});\n", i, value));
+                }
+                base
             }
         };
         Ok(expr)

crates/cli-support/src/lib.rs

@@ -313,7 +313,7 @@ impl Bindgen {
         // the webidl bindings proposal) as well as an auxiliary section for all
         // sorts of miscellaneous information and features #[wasm_bindgen]
         // supports that aren't covered by WebIDL bindings.
-        webidl::process(&mut module)?;
+        webidl::process(&mut module, self.anyref, self.emit_start)?;
 
         // Now that we've got type information from the webidl processing pass,
         // touch up the output of rustc to insert anyref shims where necessary.
@@ -324,12 +324,6 @@ impl Bindgen {
             anyref::process(&mut module)?;
         }
 
-        // If we're in a testing mode then remove the start function since we
-        // shouldn't execute it.
-        if !self.emit_start {
-            module.start = None;
-        }
-
         let aux = module
             .customs
             .delete_typed::<webidl::WasmBindgenAux>()

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

@@ -473,10 +473,14 @@ struct Context<'a> {
     vendor_prefixes: HashMap<String, Vec<String>>,
     unique_crate_identifier: &'a str,
     descriptors: HashMap<String, Descriptor>,
+    anyref_enabled: bool,
+    support_start: bool,
 }
 
 pub fn process(
     module: &mut Module,
+    anyref_enabled: bool,
+    support_start: bool,
 ) -> Result<(NonstandardWebidlSectionId, WasmBindgenAuxId), Error> {
     let mut storage = Vec::new();
     let programs = extract_programs(module, &mut storage)?;
@@ -491,6 +495,8 @@ pub fn process(
         unique_crate_identifier: "",
         module,
         start_found: false,
+        anyref_enabled,
+        support_start,
     };
     cx.init()?;
 
@@ -532,18 +538,11 @@ impl<'a> Context<'a> {
             }
         }
         for (id, intrinsic) in intrinsics {
-            bindings::register_import(
-                self.module,
-                &mut self.bindings,
-                id,
-                intrinsic.binding(),
-                ast::WebidlFunctionKind::Static,
-            )?;
-            self.aux
-                .import_map
-                .insert(id, AuxImport::Intrinsic(intrinsic));
+            self.bind_intrinsic(id, intrinsic)?;
         }
 
+        self.inject_anyref_initialization()?;
+
         if let Some(custom) = self
             .module
             .customs
@@ -612,6 +611,48 @@ impl<'a> Context<'a> {
         Ok(())
     }
 
+    // Ensure that the `start` function for this module calls the
+    // `__wbindgen_init_anyref_table` function. This'll ensure that all
+    // instances of this module have the initial slots of the anyref table
+    // initialized correctly.
+    fn inject_anyref_initialization(&mut self) -> Result<(), Error> {
+        if !self.anyref_enabled {
+            return Ok(());
+        }
+        let ty = self.module.types.add(&[], &[]);
+        let (import, import_id) = self.module.add_import_func(
+            PLACEHOLDER_MODULE,
+            "__wbindgen_init_anyref_table",
+            ty,
+        );
+
+        self.module.start = Some(match self.module.start {
+            Some(prev_start) => {
+                let mut builder = walrus::FunctionBuilder::new();
+                let call_init = builder.call(import, Box::new([]));
+                let call_prev = builder.call(prev_start, Box::new([]));
+                builder.finish(ty, Vec::new(), vec![call_init, call_prev], self.module)
+            }
+            None => import,
+        });
+        self.bind_intrinsic(import_id, Intrinsic::InitAnyrefTable)?;
+        Ok(())
+    }
+
+    fn bind_intrinsic(&mut self, id: ImportId, intrinsic: Intrinsic) -> Result<(), Error> {
+        bindings::register_import(
+            self.module,
+            &mut self.bindings,
+            id,
+            intrinsic.binding(),
+            ast::WebidlFunctionKind::Static,
+        )?;
+        self.aux
+            .import_map
+            .insert(id, AuxImport::Intrinsic(intrinsic));
+        Ok(())
+    }
+
     fn program(&mut self, program: decode::Program<'a>) -> Result<(), Error> {
         self.unique_crate_identifier = program.unique_crate_identifier;
         let decode::Program {
@@ -752,6 +793,11 @@ impl<'a> Context<'a> {
         }
         self.start_found = true;
 
+        // Skip this when we're generating tests
+        if !self.support_start {
+            return Ok(());
+        }
+
         let prev_start = match self.module.start {
             Some(f) => f,
             None => {

src/anyref.rs

@@ -39,7 +39,7 @@ impl Slab {
                     internal_error("table grow failure")
                 }
                 if self.base == 0 {
-                    self.base = r as usize + (super::JSIDX_RESERVED as usize);
+                    self.base = r as usize;
                 } else if self.base + self.data.len() != r as usize {
                     internal_error("someone else allocated table entires?")
                 }