WIP.

src/frontend.rs

@@ -1,22 +1,29 @@
 //! Frontend: convert Wasm to IR.
 
 use crate::ir::*;
+use anyhow::anyhow;
 use anyhow::Result;
 use log::trace;
+use std::collections::VecDeque;
 use wasmparser::{ImportSectionEntryType, Parser, Payload, TypeDef};
 
 pub fn wasm_to_ir(bytes: &[u8]) -> Result<Module> {
     let mut module = Module::default();
     let parser = Parser::new(0);
+    let mut sigs = VecDeque::new();
     for payload in parser.parse_all(bytes) {
         let payload = payload?;
-        handle_payload(&mut module, payload)?;
+        handle_payload(&mut module, payload, &mut sigs)?;
     }
 
     Ok(module)
 }
 
-fn handle_payload<'a>(module: &mut Module, payload: Payload<'a>) -> Result<()> {
+fn handle_payload<'a>(
+    module: &mut Module,
+    payload: Payload<'a>,
+    func_sigs: &mut VecDeque<SignatureId>,
+) -> Result<()> {
     trace!("Wasm parser item: {:?}", payload);
     match payload {
         Payload::TypeSection(mut reader) => {
@@ -40,8 +47,33 @@ fn handle_payload<'a>(module: &mut Module, payload: Payload<'a>) -> Result<()> {
                 }
             }
         }
+        Payload::FunctionSection(mut reader) => {
+            for _ in 0..reader.get_count() {
+                func_sigs.push_back(reader.read()? as SignatureId);
+            }
+        }
+        Payload::CodeSectionEntry(body) => {
+            let sig = func_sigs
+                .pop_front()
+                .ok_or_else(|| anyhow!("mismatched func section and code section sizes"))?;
+            let body = parse_body(body)?;
+            module.funcs.push(FuncDecl::Body(sig as SignatureId, body));
+        }
         _ => {}
     }
 
     Ok(())
 }
+
+fn parse_body(body: wasmparser::FunctionBody) -> Result<FunctionBody> {
+    let mut ret = FunctionBody::default();
+    let mut locals = body.get_locals_reader()?;
+    for _ in 0..locals.get_count() {
+        let (count, ty) = locals.read()?;
+        for _ in 0..count {
+            ret.locals.push(ty);
+        }
+    }
+
+    Ok(ret)
+}