fixes to build for WASM

Author: Vipul-Cariappa

CMakeLists.txt

@@ -7,10 +7,23 @@ include(CMakeSystemSpecificInformation)
 set(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
 set(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
 
+if (EMSCRIPTEN)
+    set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS TRUE)
+    set(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "-s SIDE_MODULE=1")
+    set(CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS "-s SIDE_MODULE=1")
+    set(CMAKE_STRIP FALSE)
+endif()
+
 add_library(cppyy-backend SHARED
     clingwrapper/src/clingwrapper.cxx
 )
 
+if (EMSCRIPTEN)
+    target_link_options(cppyy-backend
+        PUBLIC "SHELL: -s WASM_BIGINT"
+    )
+endif()
+
 # set_target_properties(cppyy-backend PROPERTIES VERSION ${PROJECT_VERSION})
 
 # set_target_properties(cppyy-backend PROPERTIES PUBLIC_HEADER include/cpp_cppyy.h)

clingwrapper/src/clingwrapper.cxx

@@ -206,6 +206,7 @@ class ApplicationStarter {
                 g_builtins.insert(name+a);
         }
 
+#ifndef __EMSCRIPTEN__
     // disable fast path if requested
         if (getenv("CPPYY_DISABLE_FASTPATH")) gEnableFastPath = false;
 
@@ -230,6 +231,7 @@ class ApplicationStarter {
         Cpp::AddIncludePath((ClingBuildDir + "/include").c_str());
         Cpp::AddIncludePath((std::string(CPPINTEROP_DIR) + "/include").c_str());
         Cpp::LoadLibrary("libstdc++", /* lookup= */ true);
+#endif
 
         // load frequently used headers
         const char* code =

python/cppyy_backend/loader.py

@@ -19,7 +19,7 @@
 
 if 'win32' in sys.platform:
     soext = '.dll'
-elif 'linux' in sys.platform:
+elif 'linux' in sys.platform or 'emscripten' in sys.platform:
     soext = '.so'
 else:
     soext = '.dylib'