From 87efdd167043ec529df5342a21d40a645763a2d1 Mon Sep 17 00:00:00 2001
From: Markus Rudolph <markus.rudolph@typefox.io>
Date: Mon, 5 Aug 2024 14:37:58 +0200
Subject: [PATCH] Add `Module::getOrInsertGlobal(string, llvm::Type)`

---
 include/IR/Module.h     |  2 ++
 include/Util/ErrMsg.h   |  1 +
 llvm-bindings.d.ts      |  2 ++
 src/IR/Module.cpp       | 12 ++++++++++++
 tests/IR/Module.spec.ts |  9 +++++++++
 5 files changed, 26 insertions(+)

diff --git a/include/IR/Module.h b/include/IR/Module.h
index d1182bc..9966130 100644
--- a/include/IR/Module.h
+++ b/include/IR/Module.h
@@ -48,6 +48,8 @@ class Module : public Napi::ObjectWrap<Module> {
 
     Napi::Value getGlobalVariable(const Napi::CallbackInfo &info);
 
+    Napi::Value getOrInsertGlobal(const Napi::CallbackInfo &info);
+
     void addModuleFlag(const Napi::CallbackInfo &info);
 
     Napi::Value empty(const Napi::CallbackInfo &info);
diff --git a/include/Util/ErrMsg.h b/include/Util/ErrMsg.h
index 886e806..0d5a34a 100644
--- a/include/Util/ErrMsg.h
+++ b/include/Util/ErrMsg.h
@@ -24,6 +24,7 @@ namespace ErrMsg {
             constexpr const char *getFunction = "Module.getFunction needs to be called with: (name: string)";
             constexpr const char *getOrInsertFunction = "Module.getOrInsertFunction needs to be called with: (name: string, fnType: FunctionType)";
             constexpr const char *getGlobalVariable = "Module.getGlobalVariable needs to be called with: (name: string, allowInternal?: boolean)";
+            constexpr const char *getOrInsertGlobal = "Module.getOrInsertGlobal needs to be called with: (name: string, type: Type)";
             constexpr const char *addModuleFlag = "Module.addModuleFlag needs to be called with (behavior: number, key: string, value: number)"
                                                   "\n\t - limit: behavior should belong to [1, 7]";
         }
diff --git a/llvm-bindings.d.ts b/llvm-bindings.d.ts
index d1fc84a..7d8d60f 100644
--- a/llvm-bindings.d.ts
+++ b/llvm-bindings.d.ts
@@ -227,6 +227,8 @@ declare namespace llvm {
 
         public getGlobalVariable(name: string, allowInternal?: boolean): GlobalVariable | null;
 
+        public getOrInsertGlobal(name: string, varType: Type): FunctionCallee;
+
         public addModuleFlag(behavior: number, key: string, value: number): void;
 
         public empty(): boolean;
diff --git a/src/IR/Module.cpp b/src/IR/Module.cpp
index 8d91a3c..56c1a3b 100644
--- a/src/IR/Module.cpp
+++ b/src/IR/Module.cpp
@@ -31,6 +31,7 @@ void Module::Init(Napi::Env env, Napi::Object &exports) {
             InstanceMethod("getFunction", &Module::getFunction),
             InstanceMethod("getOrInsertFunction", &Module::getOrInsertFunction),
             InstanceMethod("getGlobalVariable", &Module::getGlobalVariable),
+            InstanceMethod("getOrInsertGlobal", &Module::getOrInsertGlobal),
             InstanceMethod("addModuleFlag", &Module::addModuleFlag),
             InstanceMethod("empty", &Module::empty),
             InstanceMethod("print", &Module::print)
@@ -198,6 +199,17 @@ Napi::Value Module::getGlobalVariable(const Napi::CallbackInfo &info) {
     throw Napi::TypeError::New(env, ErrMsg::Class::Module::getGlobalVariable);
 }
 
+Napi::Value Module::getOrInsertGlobal(const Napi::CallbackInfo &info) {
+    Napi::Env env = info.Env();
+    if (info.Length() == 2 && info[0].IsString() && Type::IsClassOf(info[1])) {
+        std::string functionName = info[0].As<Napi::String>();
+        llvm::Type *type = Type::Extract(info[1]);
+        llvm::Constant* glob = module->getOrInsertGlobal(functionName, type);
+        return GlobalVariable::New(env, dyn_cast_or_null<llvm::GlobalVariable>(glob));
+    }
+    throw Napi::TypeError::New(env, ErrMsg::Class::Module::getOrInsertGlobal);
+}
+
 void Module::addModuleFlag(const Napi::CallbackInfo &info) {
     Napi::Env env = info.Env();
     if (info.Length() == 3 && info[0].IsNumber() && info[1].IsString() && info[2].IsNumber()) {
diff --git a/tests/IR/Module.spec.ts b/tests/IR/Module.spec.ts
index ec05499..784197e 100644
--- a/tests/IR/Module.spec.ts
+++ b/tests/IR/Module.spec.ts
@@ -359,4 +359,13 @@ describe('Test Module', () => {
             expect(module.print()).toMatchSnapshot();
         });
     });
+
+    describe('Global variables', () => {
+        test('Global variable declared', () => {
+            const context = new llvm.LLVMContext();
+            const module = new llvm.Module(FileName, context);
+            module.getOrInsertGlobal('HomerSimpson', llvm.Type.getInt32Ty(context));
+            expect(module.print()).toContain('@HomerSimpson');
+        });
+    });
 });