From c571915ef734836c24719b5ca3fe03cdeda4aa97 Mon Sep 17 00:00:00 2001
From: Vipul Cariappa <vipulcariappa@gmail.com>
Date: Thu, 30 Jan 2025 09:52:19 +0530
Subject: [PATCH] fixes to build for WASM

---
 CMakeLists.txt | 34 ++++++++++++++++++++++++++--------
 src/Cppyy.h    |  2 +-
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 253ec83d..f9b47ce3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,15 +11,27 @@ if (CMAKE_COMPILER_IS_GNUCXX)
 endif()
 
 message(STATUS "Looking for python ...")
-set(Python_FIND_VIRTUALENV ONLY)
-find_package (Python COMPONENTS Interpreter Development)
-if (NOT Python_FOUND)
-   set(Python_FIND_VIRTUALENV STANDARD)
-   find_package (Python COMPONENTS Interpreter Development)
-endif()
 
-if (NOT Python_Development_FOUND)
-   message(FATAL_ERROR "Python development package not found and python component required")
+if(NOT EMSCRIPTEN)
+   set(Python_FIND_VIRTUALENV ONLY)
+   find_package (Python COMPONENTS Interpreter Development)
+   if (NOT Python_FOUND)
+      set(Python_FIND_VIRTUALENV STANDARD)
+      find_package (Python COMPONENTS Interpreter Development)
+   endif()
+
+   if (NOT Python_Development_FOUND)
+      message(FATAL_ERROR "Python development package not found and python component required")
+   endif()
+else()
+   set(Python_INCLUDE_DIRS
+      "${CMAKE_PREFIX_PATH}/include/python3.11"
+   )
+
+   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()
 
 include_directories("${PROJECT_SOURCE_DIR}/include" "${Python_INCLUDE_DIRS}")
@@ -28,6 +40,12 @@ file (GLOB cppyy_src src/*.cxx)
 
 add_library(cppyy SHARED ${cppyy_src})
 
+if (EMSCRIPTEN)
+   target_link_options(cppyy
+      PUBLIC "SHELL: -s WASM_BIGINT"
+   )
+endif()
+
 if(APPLE)
   set_target_properties(cppyy PROPERTIES LINK_FLAGS "-undefined dynamic_lookup")
   set_target_properties(cppyy PROPERTIES SUFFIX ".so")
diff --git a/src/Cppyy.h b/src/Cppyy.h
index d2eb42b3..8928602d 100644
--- a/src/Cppyy.h
+++ b/src/Cppyy.h
@@ -354,7 +354,7 @@ namespace Cppyy {
     CPPYY_IMPORT
     TCppType_t  GetEnumConstantType(TCppScope_t scope);
     CPPYY_IMPORT
-    long long   GetEnumDataValue(TCppScope_t scope);
+    TCppIndex_t   GetEnumDataValue(TCppScope_t scope);
     CPPYY_IMPORT
     TCppScope_t InstantiateTemplate(
             TCppScope_t tmpl, Cpp::TemplateArgInfo* args, size_t args_size);