opt in progress

opt/src/main.rs

@@ -4,7 +4,7 @@ use std::env;
 use std::collections::HashSet;
 use parity_wasm::elements;
 
-#[derive(PartialEq, Eq, Hash, Copy, Clone)]
+#[derive(PartialEq, Eq, Hash, Copy, Clone, Debug)]
 enum Symbol {
     Import(usize),
     Global(usize),
@@ -50,6 +50,25 @@ fn resolve_global(module: &elements::Module, index: u32) -> Symbol {
     }
 }
 
+fn push_code_symbols(module: &elements::Module, opcodes: &[elements::Opcode], dest: &mut Vec<Symbol>) {
+    use parity_wasm::elements::Opcode::*;
+
+    for opcode in opcodes {
+        match opcode {
+            &Call(idx) | &CallIndirect(idx, _) => {
+                dest.push(resolve_function(module, idx));
+            },
+            &GetGlobal(idx) | &SetGlobal(idx) => {
+                dest.push(resolve_global(module, idx))
+            },
+            &If(_, ref block) | &Loop(_, ref block) | &Block(_, ref block) => {
+                push_code_symbols(module, block.elements(), dest);
+            },
+            _ => { },
+        } 
+    }
+}
+
 fn expand_symbols(module: &elements::Module, set: &mut HashSet<Symbol>) {
     use Symbol::*;
 
@@ -58,23 +77,55 @@ fn expand_symbols(module: &elements::Module, set: &mut HashSet<Symbol>) {
     let mut fringe = set.iter().cloned().collect::<Vec<Symbol>>();
     loop {
         let next = match fringe.pop() {
+            Some(s) if stop.contains(&s) => { continue; } 
             Some(s) => s,
             _ => { break; }
         };
-
-        if stop.contains(&next) {
-            continue;
-        }
+        println!("Processing symbol {:?}", next);
 
         match next {
             Export(idx) => {
                 let entry = &module.export_section().expect("Export section to exist").entries()[idx];
                 match entry.internal() {
-                    &elements::Internal::Function(func_idx) => { fringe.push(resolve_function(module, func_idx)); },
-                    &elements::Internal::Global(global_idx) => { fringe.push(resolve_global(module, global_idx)); },
+                    &elements::Internal::Function(func_idx) => {
+                        let symbol = resolve_function(module, func_idx); 
+                        if !stop.contains(&symbol) {
+                            fringe.push(symbol);
+                        }
+                        set.insert(symbol);
+                    },
+                    &elements::Internal::Global(global_idx) => {
+                        let symbol = resolve_global(module, global_idx);
+                        if !stop.contains(&symbol) {
+                            fringe.push(symbol);
+                        }
+                        set.insert(symbol); 
+                    },
                     _ => {}
                 }
             },
+            Function(idx) => {
+                let body = &module.code_section().expect("Code section to exist").bodies()[idx];
+                let mut code_symbols = Vec::new();
+                push_code_symbols(module, body.code().elements(), &mut code_symbols);
+                for symbol in code_symbols.drain(..) {
+                    if !stop.contains(&symbol) {
+                        fringe.push(symbol);
+                    }
+                    set.insert(symbol);
+                }
+            },
+            Global(idx) => {
+                let entry = &module.global_section().expect("Global section to exist").entries()[idx];
+                let mut code_symbols = Vec::new();
+                push_code_symbols(module, entry.init_expr().code(), &mut code_symbols);
+                for symbol in code_symbols.drain(..) {
+                    if !stop.contains(&symbol) {
+                        fringe.push(symbol);
+                    }
+                    set.insert(symbol);
+                }                
+            }
             _ => {}
         }
 
@@ -112,6 +163,10 @@ fn main() {
     // that are already used by those which already there
     expand_symbols(&mut module, &mut stay);
 
+    for symbol in stay.iter() {
+        println!("symbol to stay: {:?}", symbol);
+    }
+
     // Finally, delete all items one by one, updating reference indices in the process
     //   (todo: initial naive impementation can be optimized to avoid multiple passes)