Frame tests for loading shared objects for the emscripten build (#548)

* Frame tests for loading shared objects and fetching symbol address

Author: anutosh491

lib/Interpreter/CppInterOpInterpreter.h

@@ -17,6 +17,7 @@
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/GlobalDecl.h"
 #include "clang/Basic/LangOptions.h"
+#include "clang/Basic/TargetOptions.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendOptions.h"
 #include "clang/Lex/Preprocessor.h"
@@ -36,6 +37,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/TargetParser/Triple.h"
 
 #include <utility>
 #include <vector>
@@ -412,6 +414,17 @@ class Interpreter {
   }
 
   CompilationResult loadLibrary(const std::string& filename, bool lookup) {
+    llvm::Triple triple(getCompilerInstance()->getTargetOpts().Triple);
+    if (triple.isWasm()) {
+      // On WASM, dlopen-style canonical lookup has no effect.
+      if (auto Err = inner->LoadDynamicLibrary(filename.c_str())) {
+        llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(),
+                                    "loadLibrary: ");
+        return kFailure;
+      }
+      return kSuccess;
+    }
+
     DynamicLibraryManager* DLM = getDynamicLibraryManager();
     std::string canonicalLib;
     if (lookup)

unittests/CppInterOp/CMakeLists.txt

@@ -97,6 +97,7 @@ if(EMSCRIPTEN)
     PUBLIC "SHELL: -s STACK_SIZE=32mb"
     PUBLIC "SHELL: -s INITIAL_MEMORY=128mb"
     PUBLIC "SHELL: --preload-file ${SYSROOT_PATH}/include@/include"
+    PUBLIC "SHELL: --preload-file ${CMAKE_CURRENT_BINARY_DIR}/TestSharedLib/unittests/bin/Release/libTestSharedLib.so@/libTestSharedLib.so"
   )
 endif()
 

unittests/CppInterOp/DynamicLibraryManagerTest.cpp

@@ -1,5 +1,6 @@
 #include "gtest/gtest.h"
 
+#include "clang/Basic/Version.h"
 #include "clang/Interpreter/CppInterOp.h"
 
 #include "llvm/Support/FileSystem.h"
@@ -57,3 +58,29 @@ TEST(DynamicLibraryManagerTest, Sanity) {
   // invalidated...
   // EXPECT_FALSE(Cpp::GetFunctionAddress("ret_zero"));
 }
+
+TEST(DynamicLibraryManagerTest, BasicSymbolLookup) {
+#ifndef EMSCRIPTEN
+  GTEST_SKIP() << "This test is only intended for Emscripten builds.";
+#else
+  #if CLANG_VERSION_MAJOR < 20
+    GTEST_SKIP() << "Support for loading shared libraries was added in LLVM 20.";
+  #endif
+#endif
+
+  ASSERT_TRUE(Cpp::CreateInterpreter());
+  EXPECT_FALSE(Cpp::GetFunctionAddress("ret_zero"));
+
+  // Load the library manually. Use known preload path (MEMFS path)
+  const char* wasmLibPath = "libTestSharedLib.so";  // Preloaded path in MEMFS
+  EXPECT_TRUE(Cpp::LoadLibrary(wasmLibPath, false));
+
+  Cpp::Process("");
+
+  void* Addr = Cpp::GetFunctionAddress("ret_zero");
+  EXPECT_NE(Addr, nullptr) << "Symbol 'ret_zero' not found after dlopen.";
+
+  using RetZeroFn = int (*)();
+  auto Fn = reinterpret_cast<RetZeroFn>(Addr);
+  EXPECT_EQ(Fn(), 0);
+}