Add getGlobal to binaryen.js (#2142)

We have `getFunction`, but not `getGlobal` because its name clashed with
APIs for the deprecated instruction `get_global`. Now we have reflected
instruction renaming in code, we can add it for consistency.

Author: aheejin

build-js.sh

@@ -754,6 +754,7 @@ export_function "_BinaryenAddFunction"
 export_function "_BinaryenGetFunction"
 export_function "_BinaryenRemoveFunction"
 export_function "_BinaryenAddGlobal"
+export_function "_BinaryenGetGlobal"
 export_function "_BinaryenRemoveGlobal"
 export_function "_BinaryenAddFunctionImport"
 export_function "_BinaryenAddTableImport"

src/binaryen-c.cpp

@@ -2751,6 +2751,15 @@ BinaryenGlobalRef BinaryenAddGlobal(BinaryenModuleRef module,
   wasm->addGlobal(ret);
   return ret;
 }
+BinaryenGlobalRef BinaryenGetGlobal(BinaryenModuleRef module,
+                                    const char* name) {
+  if (tracing) {
+    std::cout << "  BinaryenGetGlobal(the_module, \"" << name << "\");\n";
+  }
+
+  auto* wasm = (Module*)module;
+  return wasm->getGlobal(name);
+}
 void BinaryenRemoveGlobal(BinaryenModuleRef module, const char* name) {
   if (tracing) {
     std::cout << "  BinaryenRemoveGlobal(the_module, \"" << name << "\");\n";

src/binaryen-c.h

@@ -853,11 +853,9 @@ BinaryenFunctionRef BinaryenAddFunction(BinaryenModuleRef module,
                                         BinaryenType* varTypes,
                                         BinaryenIndex numVarTypes,
                                         BinaryenExpressionRef body);
-
 // Gets a function reference by name.
 BinaryenFunctionRef BinaryenGetFunction(BinaryenModuleRef module,
                                         const char* name);
-
 // Removes a function by name.
 void BinaryenRemoveFunction(BinaryenModuleRef module, const char* name);
 
@@ -913,6 +911,8 @@ BinaryenGlobalRef BinaryenAddGlobal(BinaryenModuleRef module,
                                     BinaryenType type,
                                     int8_t mutable_,
                                     BinaryenExpressionRef init);
+// Gets a global reference by name.
+BinaryenGlobalRef BinaryenGetGlobal(BinaryenModuleRef module, const char* name);
 void BinaryenRemoveGlobal(BinaryenModuleRef module, const char* name);
 
 // Function table. One per module

src/js/binaryen.js-post.js

@@ -1776,6 +1776,11 @@ function wrapModule(module, self) {
       return Module['_BinaryenAddGlobal'](module, strToStack(name), type, mutable, init);
     });
   }
+  self['getGlobal'] = function(name) {
+    return preserveStack(function() {
+      return Module['_BinaryenGetGlobal'](module, strToStack(name));
+    });
+  };
   self['removeGlobal'] = function(name) {
     return preserveStack(function() {
       return Module['_BinaryenRemoveGlobal'](module, strToStack(name));

test/binaryen.js/global.js

@@ -13,6 +13,8 @@ var module = new Binaryen.Module();
 var initExpr = module.i32.const(1);
 var global = module.addGlobal("a-global", Binaryen.i32, false, initExpr);
 
+console.log("GetGlobal is equal: " + (global === module.getGlobal("a-global")));
+
 var globalInfo = Binaryen.getGlobalInfo(global);
 console.log("getGlobalInfo=" + JSON.stringify(cleanInfo(globalInfo)));
 

test/binaryen.js/global.js.txt

@@ -1,3 +1,4 @@
+GetGlobal is equal: true
 getGlobalInfo={"module":"","base":"","mutable":false}
 getExpressionInfo(init)={"id":14,"value":1}
 (i32.const 1)