Fix Emscripten shared library size llvm 21

Author: mcbarton

.github/workflows/emscripten.yml

@@ -329,6 +329,7 @@ jobs:
           {
             git apply -v emscripten-clang21-1-shift-temporary-files-to-tmp-dir.patch
             git apply -v emscripten-clang21-2-enable_exception_handling.patch
+            git apply -v emscripten-clang21-3-llvm-abi-annotation-remote.patch
           }
           cd build
           echo "Apply clang${{ matrix.clang-runtime }}-*.patch patches:"
@@ -539,14 +540,14 @@ jobs:
 
         emmake make -j ${{ env.ncpus }} check-cppinterop
         os="${{ matrix.os }}"
-        #if [[ "${os}" != macos* ]] ; then
-        #  actual_size=$(stat -c%s "./lib/libclangCppInterOp.so")
-        #  max_size=$((40 * 1024 * 1024))
-        #  if [[ "$actual_size" -gt "$max_size" ]]; then
-        #    echo "Error: libclangCppInterOp.so is larger than 40 MB."
-        #    exit 1
-        #  fi
-        #fi
+        if [[ "${os}" != macos* ]] ; then
+          actual_size=$(stat -c%s "./lib/libclangCppInterOp.so")
+          max_size=$((40 * 1024 * 1024))
+          if [[ "$actual_size" -gt "$max_size" ]]; then
+            echo "Error: libclangCppInterOp.so is larger than 40 MB."
+            exit 1
+          fi
+        fi
         cd ./unittests/CppInterOp/
         # Fresh install browsers, and run Emscripten tests in them
         # This is to match the Emscripten build instructions, where

Emscripten-build-instructions.md

@@ -65,6 +65,7 @@ cd .\llvm-project\
 cp -r ..\patches\llvm\emscripten-clang21*
 git apply -v emscripten-clang21-1-shift-temporary-files-to-tmp-dir.patch
 git apply -v emscripten-clang21-2-enable_exception_handling.patch
+git apply -v emscripten-clang21-3-llvm-abi-annotation-remote.patch
 ```
 
 We are now in a position to build an emscripten build of llvm by executing the following on Linux

docs/Emscripten-build-instructions.rst

@@ -84,6 +84,7 @@ On Windows execute the following
    cp -r ..\patches\llvm\emscripten-clang21*
    git apply -v emscripten-clang21-1-shift-temporary-files-to-tmp-dir.patch
    git apply -v emscripten-clang21-2-enable_exception_handling.patch
+   git apply -v emscripten-clang21-3-llvm-abi-annotation-remote.patch
 
 We are now in a position to build an emscripten build of llvm by executing the following on Linux
 and osx
@@ -429,4 +430,4 @@ and on Windows execute
                       --contents xeus-cpp/notebooks/images/marie.png ` 
                       --contents xeus-cpp/notebooks/audio/audio.wav `
                       --XeusAddon.mounts="$env:PREFIX/share/xeus-cpp/tagfiles:/share/xeus-cpp/tagfiles" `
-                      --XeusAddon.mounts="$env:PREFIX/etc/xeus-cpp/tags.d:/etc/xeus-cpp/tags.d"
+                      --XeusAddon.mounts="$env:PREFIX/etc/xeus-cpp/tags.d:/etc/xeus-cpp/tags.d"

patches/llvm/emscripten-clang21-3-llvm-abi-annotation-remote.patch

@@ -0,0 +1,17 @@
+diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
+index 297d3e9b0..6aaa5d4e3 100644
+--- a/llvm/include/llvm/Support/Compiler.h
++++ b/llvm/include/llvm/Support/Compiler.h
+@@ -202,10 +202,10 @@
+ #define LLVM_EXPORT_TEMPLATE
+ #define LLVM_ABI_EXPORT LLVM_ABI
+ #elif defined(__MACH__) || defined(__WASM__) || defined(__EMSCRIPTEN__)
+-#define LLVM_ABI __attribute__((visibility("default")))
++#define LLVM_ABI
+ #define LLVM_TEMPLATE_ABI
+ #define LLVM_EXPORT_TEMPLATE
+-#define LLVM_ABI_EXPORT LLVM_ABI
++#define LLVM_ABI_EXPORT
+ #endif
+ #endif
+ #endif