emit asm function tables in wasm2asm

4 files changed, 50 insertions, 0 deletions

diff --git a/src/asm_v_wasm.h b/src/asm_v_wasm.h
index 323d255ee..829d79930 100644
--- a/src/asm_v_wasm.h
+++ b/src/asm_v_wasm.h
@@ -47,6 +47,16 @@ std::string getSig(FunctionType *type) {
   return ret;
 }
 
+std::string getSig(Function *func) {
+  // generate signature
+  std::string ret;
+  ret += getSig(func->result);
+  for (auto param : func->params) {
+    ret += getSig(param.type);
+  }
+  return ret;
+}
+
 } // namespace wasm
 
 #endif // _asm_v_wasm_h_
diff --git a/src/wasm2asm.h b/src/wasm2asm.h
index 836fc450c..62baf1b54 100644
--- a/src/wasm2asm.h
+++ b/src/wasm2asm.h
@@ -164,6 +164,7 @@ private:
 
   void addBasics(Ref ast);
   void addImport(Ref ast, Import *import);
+  void addTables(Ref ast, Module *wasm);
 };
 
 Ref Wasm2AsmBuilder::processWasm(Module* wasm) {
@@ -192,6 +193,7 @@ Ref Wasm2AsmBuilder::processWasm(Module* wasm) {
   for (auto func : wasm->functions) {
     asmFunc[3]->push_back(processFunction(func));
   }
+  addTables(asmFunc[3], wasm);
   // table XXX
   // memory XXX
   return ret;
@@ -253,6 +255,39 @@ void Wasm2AsmBuilder::addImport(Ref ast, Import *import) {
   );
 }
 
+void Wasm2AsmBuilder::addTables(Ref ast, Module *wasm) {
+  std::map<std::string, std::vector<IString>> tables; // asm.js tables, sig => contents of table
+  for (size_t i = 0; i < wasm->table.names.size(); i++) {
+    Name name = wasm->table.names[i];
+    auto func = wasm->functionsMap[name];
+    std::string sig = getSig(func);
+    auto& table = tables[sig];
+    if (table.size() == 0) {
+      // fill it with the first of its type seen. we have to fill with something; and for asm2wasm output, the first is the null anyhow
+      table.resize(tableSize);
+      for (int j = 0; j < tableSize; j++) {
+        table[j] = fromName(name);
+      }
+    } else {
+      table[i] = fromName(name);
+    }
+  }
+  for (auto& pair : tables) {
+    auto& sig = pair.first;
+    auto& table = pair.second;
+    std::string stable = std::string("FUNCTION_TABLE_") + sig;
+    IString asmName = IString(stable.c_str(), false);
+    // add to asm module
+    Ref theVar = ValueBuilder::makeVar();
+    ast->push_back(theVar);
+    Ref theArray = ValueBuilder::makeArray();
+    ValueBuilder::appendToVar(theVar, asmName, theArray);
+    for (auto& name : table) {
+      ValueBuilder::appendToArray(theArray, ValueBuilder::makeName(name));
+    }
+  }
+}
+
 Ref Wasm2AsmBuilder::processFunction(Function* func) {
   Ref ret = ValueBuilder::makeFunction(fromName(func->name));
   frees.clear();
diff --git a/test/emcc_O2_hello_world.2asm.js b/test/emcc_O2_hello_world.2asm.js
index 37ec11b41..09ee16196 100644
--- a/test/emcc_O2_hello_world.2asm.js
+++ b/test/emcc_O2_hello_world.2asm.js
@@ -2527,5 +2527,8 @@ function asmFunc(global, env, buffer) {
   abort(2 | 0)
  }
  
+ var FUNCTION_TABLE_ii = [b0, ___stdio_close, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0, b0];
+ var FUNCTION_TABLE_iiii = [b1, b1, b1, b1, ___stdout_write, ___stdio_seek, b1, ___stdio_write, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1, b1];
+ var FUNCTION_TABLE_vi = [b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, _cleanup_418, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2, b2];
 }
 
diff --git a/test/unit.2asm.js b/test/unit.2asm.js
index a8320d77c..b705e1e64 100644
--- a/test/unit.2asm.js
+++ b/test/unit.2asm.js
@@ -212,5 +212,7 @@ function asmFunc(global, env, buffer) {
   
  }
  
+ var FUNCTION_TABLE_d = [importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles, importedDoubles];
+ var FUNCTION_TABLE_v = [z, big_negative, z, z, w, w, z, w, z, neg, z, z, z, z, z, z];
 }