Store richer adapter types, don't use instructions for TypeScript (#1945)

This commit updates how TypeScript signature are generated from adapters
in wasm-bindgen. A richer set of `AdapterType` types are now stored
which record information about optional types and such. These direct
`AdapterType` values are then used to calculate the TypeScript
signature, rather than following the instructions in an adapter function
(which only works anyway for wasm-bindgen generated adapters).

This should be more robust since it reads the actual true signature of
the adapter to generate the TypeScript signature, rather than attempting
to ad-hoc-ly infer it from the various instructions, which was already
broken.

A number of refactorings were involved here, but the main pieces are:

* The `AdapterType` type is a bit more rich now to describe more
  Rust-like types.
* The `TypescriptArg` structure is now gone and instead return values
  are directly inferred from type signatures of adapters.
* The `typescript_{required,optional}` methods are no longer needed.
* The return of `JsBuilder::process` was enhanced to return more values,
  rather than storing some return values on the structure itself.

Closes #1926

Author: alexcrichton

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

@@ -1950,7 +1950,13 @@ impl<'a> Context<'a> {
         }
 
         // Process the `binding` and generate a bunch of JS/TypeScript/etc.
-        let js = builder
+        let binding::JsFunction {
+            ts_sig,
+            ts_arg_tys,
+            ts_ret_ty,
+            js_doc,
+            code,
+        } = builder
             .process(&adapter, instrs, arg_names)
             .with_context(|| match kind {
                 Kind::Export(e) => format!("failed to generate bindings for `{}`", e.debug_name),
@@ -1963,8 +1969,6 @@ impl<'a> Context<'a> {
                 }
                 Kind::Adapter => format!("failed to generates bindings for adapter"),
             })?;
-        let ts = builder.typescript_signature();
-        let js_doc = builder.js_doc_comments();
 
         // Once we've got all the JS then put it in the right location depending
         // on what's being exported.
@@ -1973,11 +1977,11 @@ impl<'a> Context<'a> {
                 let docs = format_doc_comments(&export.comments, Some(js_doc));
                 match &export.kind {
                     AuxExportKind::Function(name) => {
-                        self.export(&name, &format!("function{}", js), Some(docs))?;
+                        self.export(&name, &format!("function{}", code), Some(docs))?;
                         self.globals.push_str("\n");
                         self.typescript.push_str("export function ");
                         self.typescript.push_str(&name);
-                        self.typescript.push_str(&ts);
+                        self.typescript.push_str(&ts_sig);
                         self.typescript.push_str(";\n");
                     }
                     AuxExportKind::Constructor(class) => {
@@ -1986,36 +1990,36 @@ impl<'a> Context<'a> {
                             bail!("found duplicate constructor for class `{}`", class);
                         }
                         exported.has_constructor = true;
-                        exported.push(&docs, "constructor", "", &js, &ts);
+                        exported.push(&docs, "constructor", "", &code, &ts_sig);
                     }
                     AuxExportKind::Getter { class, field } => {
-                        let ret_ty = builder.ts_ret.as_ref().unwrap().ty.clone();
+                        let ret_ty = ts_ret_ty.unwrap();
                         let exported = require_class(&mut self.exported_classes, class);
-                        exported.push_getter(&docs, field, &js, &ret_ty);
+                        exported.push_getter(&docs, field, &code, &ret_ty);
                     }
                     AuxExportKind::Setter { class, field } => {
-                        let arg_ty = builder.ts_args[0].ty.clone();
+                        let arg_ty = ts_arg_tys[0].clone();
                         let exported = require_class(&mut self.exported_classes, class);
-                        exported.push_setter(&docs, field, &js, &arg_ty);
+                        exported.push_setter(&docs, field, &code, &arg_ty);
                     }
                     AuxExportKind::StaticFunction { class, name } => {
                         let exported = require_class(&mut self.exported_classes, class);
-                        exported.push(&docs, name, "static ", &js, &ts);
+                        exported.push(&docs, name, "static ", &code, &ts_sig);
                     }
                     AuxExportKind::Method { class, name, .. } => {
                         let exported = require_class(&mut self.exported_classes, class);
-                        exported.push(&docs, name, "", &js, &ts);
+                        exported.push(&docs, name, "", &code, &ts_sig);
                     }
                 }
             }
             Kind::Import(core) => {
                 self.wasm_import_definitions
-                    .insert(core, format!("function{}", js));
+                    .insert(core, format!("function{}", code));
             }
             Kind::Adapter => {
                 self.globals.push_str("function ");
                 self.globals.push_str(&self.adapter_name(id));
-                self.globals.push_str(&js);
+                self.globals.push_str(&code);
                 self.globals.push_str("\n\n");
             }
         }

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

@@ -67,7 +67,7 @@ fn extract_xform<'a>(
     if let Some(Instruction::Retptr) = instructions.first().map(|e| &e.instr) {
         instructions.remove(0);
         let mut types = Vec::new();
-        instructions.retain(|instruction| match instruction.instr {
+        instructions.retain(|instruction| match &instruction.instr {
             Instruction::LoadRetptr { ty, .. } => {
                 types.push(ty.to_wasm().unwrap());
                 false

crates/cli-support/src/multivalue.rs

@@ -69,7 +69,7 @@ impl InstructionBuilder<'_, '_> {
             }
             Descriptor::RustStruct(class) => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Struct(class.clone())],
                     Instruction::I32FromAnyrefRustOwned {
                         class: class.clone(),
                     },
@@ -147,7 +147,7 @@ impl InstructionBuilder<'_, '_> {
         match arg {
             Descriptor::RustStruct(class) => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Struct(class.clone())],
                     Instruction::I32FromAnyrefRustBorrow {
                         class: class.clone(),
                     },
@@ -217,56 +217,56 @@ impl InstructionBuilder<'_, '_> {
         match arg {
             Descriptor::Anyref => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Anyref.option()],
                     Instruction::I32FromOptionAnyref {
                         table_and_alloc: None,
                     },
                     &[AdapterType::I32],
                 );
             }
-            Descriptor::I8 => self.in_option_sentinel(),
-            Descriptor::U8 => self.in_option_sentinel(),
-            Descriptor::I16 => self.in_option_sentinel(),
-            Descriptor::U16 => self.in_option_sentinel(),
+            Descriptor::I8 => self.in_option_sentinel(AdapterType::S8),
+            Descriptor::U8 => self.in_option_sentinel(AdapterType::U8),
+            Descriptor::I16 => self.in_option_sentinel(AdapterType::S16),
+            Descriptor::U16 => self.in_option_sentinel(AdapterType::U16),
             Descriptor::I32 => self.in_option_native(ValType::I32),
             Descriptor::U32 => self.in_option_native(ValType::I32),
             Descriptor::F32 => self.in_option_native(ValType::F32),
             Descriptor::F64 => self.in_option_native(ValType::F64),
             Descriptor::I64 | Descriptor::U64 => {
-                let signed = match arg {
-                    Descriptor::I64 => true,
-                    _ => false,
+                let (signed, ty) = match arg {
+                    Descriptor::I64 => (true, AdapterType::S64.option()),
+                    _ => (false, AdapterType::U64.option()),
                 };
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[ty],
                     Instruction::I32SplitOption64 { signed },
-                    &[AdapterType::I32; 3],
+                    &[AdapterType::I32, AdapterType::I32, AdapterType::I32],
                 );
             }
             Descriptor::Boolean => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Bool.option()],
                     Instruction::I32FromOptionBool,
                     &[AdapterType::I32],
                 );
             }
             Descriptor::Char => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::String.option()],
                     Instruction::I32FromOptionChar,
                     &[AdapterType::I32],
                 );
             }
             Descriptor::Enum { hole } => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::U32.option()],
                     Instruction::I32FromOptionEnum { hole: *hole },
                     &[AdapterType::I32],
                 );
             }
             Descriptor::RustStruct(name) => {
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Struct(name.clone()).option()],
                     Instruction::I32FromOptionRust {
                         class: name.to_string(),
                     },
@@ -279,13 +279,13 @@ impl InstructionBuilder<'_, '_> {
                 let mem = self.cx.memory()?;
                 let realloc = self.cx.realloc();
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::String.option()],
                     Instruction::OptionString {
                         malloc,
                         mem,
                         realloc,
                     },
-                    &[AdapterType::I32; 2],
+                    &[AdapterType::I32, AdapterType::I32],
                 );
             }
 
@@ -299,9 +299,9 @@ impl InstructionBuilder<'_, '_> {
                 let malloc = self.cx.malloc()?;
                 let mem = self.cx.memory()?;
                 self.instruction(
-                    &[AdapterType::Anyref],
+                    &[AdapterType::Vector(kind).option()],
                     Instruction::OptionVector { kind, malloc, mem },
-                    &[AdapterType::I32; 2],
+                    &[AdapterType::I32, AdapterType::I32],
                 );
             }
 
@@ -343,7 +343,7 @@ impl InstructionBuilder<'_, '_> {
         // fetch them from the parameters.
         if !self.return_position {
             for input in inputs {
-                self.get(*input);
+                self.get(input.clone());
             }
         } else {
             self.input.extend_from_slice(inputs);
@@ -385,16 +385,17 @@ impl InstructionBuilder<'_, '_> {
     }
 
     fn in_option_native(&mut self, wasm: ValType) {
+        let ty = AdapterType::from_wasm(wasm).unwrap();
         self.instruction(
-            &[AdapterType::Anyref],
+            &[ty.clone().option()],
             Instruction::FromOptionNative { ty: wasm },
-            &[AdapterType::I32, AdapterType::from_wasm(wasm).unwrap()],
+            &[AdapterType::I32, ty],
         );
     }
 
-    fn in_option_sentinel(&mut self) {
+    fn in_option_sentinel(&mut self, ty: AdapterType) {
         self.instruction(
-            &[AdapterType::Anyref],
+            &[ty.option()],
             Instruction::I32FromOptionU32Sentinel,
             &[AdapterType::I32],
         );