Update wasm exception handling model (use wasm-exceptions instead of exceptions)

anutosh491 · anutosh491 · commit 65a4e5b3cded · 2025-11-25T19:46:23.000+05:30
Add tests
diff --git a/.github/workflows/deploy-github-page.yml b/.github/workflows/deploy-github-page.yml
@@ -56,9 +56,6 @@ jobs:
           echo "PREFIX=$PREFIX" >> $GITHUB_ENV
           export SYSROOT_PATH=$BUILD_PREFIX/opt/emsdk/upstream/emscripten/cache/sysroot
 
-          micromamba create -n node-env -c conda-forge nodejs=22
-          export PATH="$MAMBA_ROOT_PREFIX/envs/node-env/bin:$PATH"
-
           emcmake cmake \
             -DCMAKE_BUILD_TYPE=Release                        \
             -DCMAKE_INSTALL_PREFIX=$PREFIX                    \
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
@@ -241,9 +241,6 @@ jobs:
           echo "PREFIX=$PREFIX" >> $GITHUB_ENV
           export SYSROOT_PATH=$BUILD_PREFIX/opt/emsdk/upstream/emscripten/cache/sysroot
 
-          micromamba create -n node-env -c conda-forge nodejs=22
-          export PATH="$MAMBA_ROOT_PREFIX/envs/node-env/bin:$PATH"
-
           emcmake cmake \
             -DCMAKE_BUILD_TYPE=Release                        \
             -DCMAKE_INSTALL_PREFIX=$PREFIX                    \
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -219,6 +219,8 @@ macro(xeus_cpp_set_common_options target_name)
         target_compile_options(${target_name} PUBLIC /wd4251 /wd4141)
         target_compile_options(${target_name} PUBLIC /wd4018 /wd4267 /wd4715 /wd4146 /wd4129)
         target_compile_options(${target_name} PUBLIC /EHsc)
+    elseif (EMSCRIPTEN)
+        target_compile_options(${target_name} PUBLIC -fwasm-exceptions)
     else ()
         target_compile_options(${target_name} PUBLIC -fexceptions)
     endif ()
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -71,7 +71,7 @@ micromamba create -f environment-wasm-build.yml -y
 micromamba activate xeus-cpp-wasm-build
 ```
 
-You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Prefer using node 22 and above as prior versions lead to flaky test runs. Once the test pass, run the install command.
+You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Once the test pass, run the install command.
 
 ```bash
 micromamba create -f environment-wasm-host.yml --platform=emscripten-wasm32
@@ -81,9 +81,6 @@ export BUILD_PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-build
 export PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-host
 export SYSROOT_PATH=$BUILD_PREFIX/opt/emsdk/upstream/emscripten/cache/sysroot
 
-micromamba create -n node-env -c conda-forge nodejs=22
-export PATH="$MAMBA_ROOT_PREFIX/envs/node-env/bin:$PATH"
-
 emcmake cmake \
         -DCMAKE_BUILD_TYPE=Release                        \
         -DCMAKE_INSTALL_PREFIX=$PREFIX                    \
diff --git a/README.md b/README.md
@@ -88,7 +88,7 @@ micromamba create -f environment-wasm-build.yml -y
 micromamba activate xeus-cpp-wasm-build
 ```
 
-You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Prefer using node 22 and above as prior versions lead to flaky test runs. Once the test pass, run the install command.
+You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Once the test pass, run the install command.
 ```bash
 micromamba create -f environment-wasm-host.yml --platform=emscripten-wasm32
 mkdir build
@@ -97,9 +97,6 @@ export BUILD_PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-build
 export PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-host
 export SYSROOT_PATH=$BUILD_PREFIX/opt/emsdk/upstream/emscripten/cache/sysroot
 
-micromamba create -n node-env -c conda-forge nodejs=22
-export PATH="$MAMBA_ROOT_PREFIX/envs/node-env/bin:$PATH"
-
 emcmake cmake \
         -DCMAKE_BUILD_TYPE=Release                        \
         -DCMAKE_INSTALL_PREFIX=$PREFIX                    \
diff --git a/docs/source/InstallationAndUsage.rst b/docs/source/InstallationAndUsage.rst
@@ -66,7 +66,7 @@ the following
     micromamba create -f environment-wasm-build.yml -y
     micromamba activate xeus-cpp-wasm-build
 
-You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Prefer using node 22 and above as prior versions lead to flaky test runs. Once the test pass, run the install command.
+You are now in a position to build the xeus-cpp kernel. You build and test it in node by executing the following. Once the test pass, run the install command.
 
 .. code-block:: bash
 
@@ -77,9 +77,6 @@ You are now in a position to build the xeus-cpp kernel. You build and test it in
     export PREFIX=$MAMBA_ROOT_PREFIX/envs/xeus-cpp-wasm-host
     export SYSROOT_PATH=$BUILD_PREFIX/opt/emsdk/upstream/emscripten/cache/sysroot
 
-    micromamba create -n node-env -c conda-forge nodejs=22
-    export PATH="$MAMBA_ROOT_PREFIX/envs/node-env/bin:$PATH"
-
     emcmake cmake \
 		-DCMAKE_BUILD_TYPE=Release                        \
 		-DCMAKE_INSTALL_PREFIX=$PREFIX                    \
diff --git a/environment-wasm-build.yml b/environment-wasm-build.yml
@@ -1,7 +1,7 @@
 name: xeus-cpp-wasm-build
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-4x
   - https://prefix.dev/conda-forge
 dependencies:
   - cmake
-  - emscripten_emscripten-wasm32==3.1.73
+  - emscripten_emscripten-wasm32==4.0.9
diff --git a/environment-wasm-host.yml b/environment-wasm-host.yml
@@ -1,6 +1,6 @@
 name: xeus-cpp-wasm-host
 channels:
-  - https://prefix.dev/emscripten-forge-dev
+  - https://prefix.dev/emscripten-forge-4x
   - https://prefix.dev/conda-forge
 dependencies:
   - nlohmann_json
diff --git a/share/jupyter/kernels/xc11/wasm_kernel.json.in b/share/jupyter/kernels/xc11/wasm_kernel.json.in
@@ -6,7 +6,8 @@
       "-Xclang", "-iwithsysroot/include/compat",
       "-xc",
       "-std=c11",
-      "-mllvm", "-enable-emscripten-sjlj",
+      "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj",
       "-msimd128"
   ],
   "language": "c",
diff --git a/share/jupyter/kernels/xc17/wasm_kernel.json.in b/share/jupyter/kernels/xc17/wasm_kernel.json.in
@@ -6,7 +6,8 @@
       "-Xclang", "-iwithsysroot/include/compat",
       "-xc",
       "-std=c17",
-      "-mllvm", "-enable-emscripten-sjlj",
+      "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj",
       "-msimd128"
   ],
   "language": "c",
diff --git a/share/jupyter/kernels/xc23/wasm_kernel.json.in b/share/jupyter/kernels/xc23/wasm_kernel.json.in
@@ -6,7 +6,8 @@
       "-Xclang", "-iwithsysroot/include/compat",
       "-xc",
       "-std=c23",
-      "-mllvm", "-enable-emscripten-sjlj",
+      "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj",
       "-msimd128"
   ],
   "language": "c",
diff --git a/share/jupyter/kernels/xcpp17/wasm_kernel.json.in b/share/jupyter/kernels/xcpp17/wasm_kernel.json.in
@@ -4,8 +4,8 @@
       "@XEUS_CPP_KERNELSPEC_PATH@xcpp",
       "-resource-dir", "/lib/clang/@CPPINTEROP_LLVM_VERSION_MAJOR@",
       "-Xclang", "-iwithsysroot/include/compat",
-      "-std=c++17", "-mllvm", "-enable-emscripten-cxx-exceptions",
-      "-mllvm", "-enable-emscripten-sjlj", "-msimd128"
+      "-std=c++17", "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj", "-msimd128"
   ],
   "language": "cpp",
   "metadata": {
diff --git a/share/jupyter/kernels/xcpp20/wasm_kernel.json.in b/share/jupyter/kernels/xcpp20/wasm_kernel.json.in
@@ -4,8 +4,8 @@
       "@XEUS_CPP_KERNELSPEC_PATH@xcpp",
       "-resource-dir", "/lib/clang/@CPPINTEROP_LLVM_VERSION_MAJOR@",
       "-Xclang", "-iwithsysroot/include/compat",
-      "-std=c++20", "-mllvm", "-enable-emscripten-cxx-exceptions",
-      "-mllvm", "-enable-emscripten-sjlj", "-msimd128"
+      "-std=c++20", "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj", "-msimd128"
   ],
   "language": "cpp",
   "metadata": {
diff --git a/share/jupyter/kernels/xcpp23/wasm_kernel.json.in b/share/jupyter/kernels/xcpp23/wasm_kernel.json.in
@@ -4,8 +4,8 @@
       "@XEUS_CPP_KERNELSPEC_PATH@xcpp",
       "-resource-dir", "/lib/clang/@CPPINTEROP_LLVM_VERSION_MAJOR@",
       "-Xclang", "-iwithsysroot/include/compat",
-      "-std=c++23", "-mllvm", "-enable-emscripten-cxx-exceptions",
-      "-mllvm", "-enable-emscripten-sjlj", "-msimd128"
+      "-std=c++23", "-fwasm-exceptions",
+      "-mllvm", "-wasm-enable-sjlj", "-msimd128"
   ],
   "language": "cpp",
   "metadata": {
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
@@ -54,7 +54,7 @@ if(EMSCRIPTEN)
     target_link_libraries(test_xeus_cpp PRIVATE xeus-cpp-static doctest::doctest)
 
     target_compile_options(test_xeus_cpp
-        PUBLIC "SHELL: -fexceptions"
+        PUBLIC "SHELL: -fwasm-exceptions"
     )
     # So we create a html file, as well as the javascript file
     set_target_properties(test_xeus_cpp PROPERTIES
@@ -67,10 +67,10 @@ if(EMSCRIPTEN)
     # Without this MINIFY_HTML=0 flag you end up with the situation where the creation of the
     # test_xeus_cpp.html file breaks on MacOS, but not Ubuntu
     target_link_options(test_xeus_cpp
-        PUBLIC "SHELL: -fexceptions"
+        PUBLIC "SHELL: -fwasm-exceptions"
         PUBLIC "SHELL: -s MAIN_MODULE=1"
         PUBLIC "SHELL: -s WASM_BIGINT"
-        PUBLIC "SHELL: -s ASSERTIONS=1"
+        PUBLIC "SHELL: -s ASSERTIONS=0"
         PUBLIC "SHELL: -s ALLOW_MEMORY_GROWTH=1"
         PUBLIC "SHELL: -s STACK_SIZE=32mb"
         PUBLIC "SHELL: -s INITIAL_MEMORY=128mb"
diff --git a/test/test_interpreter.cpp b/test/test_interpreter.cpp
@@ -70,7 +70,14 @@ TEST_SUITE("execute_request")
 {
     TEST_CASE("stl")
     {
-        std::vector<const char*> Args = {"stl-test-case", "-v"};
+#if defined(XEUS_CPP_EMSCRIPTEN_WASM_BUILD)
+        std::vector<const char*> Args = {
+            "-v",
+            "-Xclang", "-iwithsysroot/include/compat"
+        };
+#else
+        std::vector<const char*> Args = {/*"-v", "resource-dir", "....."*/};
+#endif
         xcpp::interpreter interpreter((int)Args.size(), Args.data());
         std::string code = "#include <vector>";
         nl::json user_expressions = nl::json::object();
@@ -136,6 +143,45 @@ TEST_SUITE("execute_request")
     }
 #endif
 
+#if defined(XEUS_CPP_EMSCRIPTEN_WASM_BUILD)
+    TEST_CASE("Emscripten Exception Handling")
+    {
+        std::vector<const char*> Args = {
+            "-std=c++20",
+            "-v",
+            "-fwasm-exceptions",
+            "-mllvm", "-wasm-enable-sjlj"
+        };
+
+        xcpp::interpreter interpreter((int)Args.size(), Args.data());
+        std::string code = "try { throw 1; } catch (...) { 0; }";
+        nl::json user_expressions = nl::json::object();
+        xeus::execute_request_config config;
+        config.silent = false;
+        config.store_history = false;
+        config.allow_stdin = false;
+        nl::json header = nl::json::object();
+        xeus::xrequest_context::guid_list id = {};
+        xeus::xrequest_context context(header, id);
+
+        std::promise<nl::json> promise;
+        std::future<nl::json> future = promise.get_future();
+        auto callback = [&promise](nl::json result) {
+            promise.set_value(result);
+        };
+
+        interpreter.execute_request(
+            std::move(context),
+            std::move(callback),
+            code,
+            std::move(config),
+            user_expressions
+        );
+        nl::json result = future.get();
+        REQUIRE(result["status"] == "ok");
+    }
+#endif
+
     TEST_CASE("fetch_documentation")
     {
         std::vector<const char*> Args = {/*"-v", "resource-dir", "....."*/};
@@ -810,7 +856,14 @@ TEST_SUITE("complete_request")
 {
     TEST_CASE("completion_test")
     {
+#if defined(XEUS_CPP_EMSCRIPTEN_WASM_BUILD)
+        std::vector<const char*> Args = {
+            "-v",
+            "-Xclang", "-iwithsysroot/include/compat"
+        };
+#else
         std::vector<const char*> Args = {/*"-v", "resource-dir", "....."*/};
+#endif
         xcpp::interpreter interpreter((int)Args.size(), Args.data());
         std::string code1 = "#include <iostream>";
         nl::json user_expressions = nl::json::object();
