Add llvm 20 Emscripten jobs

Author: mcbarton

.github/workflows/deploy-pages.yml

@@ -21,9 +21,9 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - name: osx15-arm-clang-repl-19-emscripten_wasm
+          - name: osx15-arm-clang-repl-20-emscripten_wasm
             os: macos-15
-            clang-runtime: '19'
+            clang-runtime: '20'
             cling: Off
             micromamba_shell_init: bash
             emsdk_ver: "3.1.73"

.github/workflows/emscripten.yml

@@ -42,6 +42,27 @@ jobs:
             llvm_enable_projects: "clang;lld"
             llvm_targets_to_build: "WebAssembly"
             emsdk_ver: "3.1.73"
+          - name: ubu24-arm-clang-repl-20-emscripten
+            os: ubuntu-24.04-arm
+            clang-runtime: '20'
+            cling: Off
+            llvm_enable_projects: "clang;lld"
+            llvm_targets_to_build: "WebAssembly"
+            emsdk_ver: "3.1.73"
+          - name: osx15-arm-clang-repl-20-emscripten
+            os: macos-15
+            clang-runtime: '20'
+            cling: Off
+            llvm_enable_projects: "clang;lld"
+            llvm_targets_to_build: "WebAssembly"
+            emsdk_ver: "3.1.73"
+          - name: ubu24-x86-clang-repl-20-emscripten
+            os: ubuntu-24.04
+            clang-runtime: '20'
+            cling: Off
+            llvm_enable_projects: "clang;lld"
+            llvm_targets_to_build: "WebAssembly"
+            emsdk_ver: "3.1.73"
 
     steps:
     - uses: actions/checkout@v4
@@ -212,7 +233,7 @@ jobs:
         else
           # Apply patches
           llvm_vers=$(echo "${{ matrix.clang-runtime }}" | tr '[:lower:]' '[:upper:]')
-          if [[ "${llvm_vers}" == "19" ]]; then
+          if [[ "${llvm_vers}" == "19" || "${llvm_vers}" == "20" ]]; then
             git apply -v ../patches/llvm/emscripten-clang${{ matrix.clang-runtime }}-*.patch
             echo "Apply emscripten-clang${{ matrix.clang-runtime }}-*.patch patches:"
           fi
@@ -387,6 +408,24 @@ jobs:
             cling: Off
             micromamba_shell_init: bash
             emsdk_ver: "3.1.73"
+          - name: ubu24-x86-clang-repl-20-emscripten_wasm
+            os: ubuntu-24.04
+            clang-runtime: '20'
+            cling: Off
+            micromamba_shell_init: bash
+            emsdk_ver: "3.1.73"
+          - name: osx15-arm-clang-repl-20-emscripten_wasm
+            os: macos-15
+            clang-runtime: '20'
+            cling: Off
+            micromamba_shell_init: bash
+            emsdk_ver: "3.1.73"
+          - name: ubu24-arm-clang-repl-20-emscripten_wasm
+            os: ubuntu-24.04-arm
+            clang-runtime: '20'
+            cling: Off
+            micromamba_shell_init: bash
+            emsdk_ver: "3.1.73"
 
     steps:
     - uses: actions/checkout@v4

patches/llvm/emscripten-clang20-1-CrossCompile.patch

@@ -0,0 +1,16 @@
+diff --git a/llvm/cmake/modules/CrossCompile.cmake b/llvm/cmake/modules/CrossCompile.cmake
+index 6af47b51d4c6..c635e7f5be9e 100644
+--- a/llvm/cmake/modules/CrossCompile.cmake
++++ b/llvm/cmake/modules/CrossCompile.cmake
+@@ -70,8 +70,8 @@ function(llvm_create_cross_target project_name target_name toolchain buildtype)
+   add_custom_command(OUTPUT ${${project_name}_${target_name}_BUILD}/CMakeCache.txt
+     COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
+         -DCMAKE_MAKE_PROGRAM="${CMAKE_MAKE_PROGRAM}"
+-        -DCMAKE_C_COMPILER_LAUNCHER="${CMAKE_C_COMPILER_LAUNCHER}"
+-        -DCMAKE_CXX_COMPILER_LAUNCHER="${CMAKE_CXX_COMPILER_LAUNCHER}"
++        -DCMAKE_C_COMPILER="clang"
++        -DCMAKE_CXX_COMPILER="clang++"
+         ${CROSS_TOOLCHAIN_FLAGS_${target_name}} ${CMAKE_CURRENT_SOURCE_DIR}
+         ${CROSS_TOOLCHAIN_FLAGS_${project_name}_${target_name}}
+         -DLLVM_TARGET_IS_CROSSCOMPILE_HOST=TRUE
+         

patches/llvm/emscripten-clang20-2-shift-temporary-files-to-tmp-dir.patch

@@ -0,0 +1,15 @@
+diff --git a/clang/lib/Interpreter/Wasm.cpp b/clang/lib/Interpreter/Wasm.cpp
+index aa10b160ccf8..184867e2b55f 100644
+--- a/clang/lib/Interpreter/Wasm.cpp
++++ b/clang/lib/Interpreter/Wasm.cpp
+@@ -76,8 +76,8 @@ llvm::Error WasmIncrementalExecutor::addModule(PartialTranslationUnit &PTU) {
+   llvm::TargetMachine *TargetMachine = Target->createTargetMachine(
+       PTU.TheModule->getTargetTriple(), "", "", TO, llvm::Reloc::Model::PIC_);
+   PTU.TheModule->setDataLayout(TargetMachine->createDataLayout());
+-  std::string ObjectFileName = PTU.TheModule->getName().str() + ".o";
+-  std::string BinaryFileName = PTU.TheModule->getName().str() + ".wasm";
++  std::string ObjectFileName = "/tmp/" + PTU.TheModule->getName().str() + ".o";
++  std::string BinaryFileName = "/tmp/" + PTU.TheModule->getName().str() + ".wasm";
+ 
+   std::error_code Error;
+   llvm::raw_fd_ostream ObjectFileOutput(llvm::StringRef(ObjectFileName), Error);