Remove the need for std::atomic and make it compile on arm linux.

CMakeLists.txt

@@ -98,7 +98,7 @@ if (CMAKE_COMPILER_IS_GNUCXX AND NOT APPLE)
     # add_definitions("-D_GLIBCXX_USE_CXX11_ABI=0")
 endif ()
 
-if (APPLE)
+if (APPLE OR (LLVM_JIT AND (NOT CMAKE_COMPILER_IS_GNUCXX) AND (NOT MSVC)))
     set(CMAKE_C_FLAGS "-std=c99 -O1 -g3 -Wall -Wextra -DLUA_COMPAT_5_2 -DLUA_USE_MACOSX")
     set(CMAKE_C_FLAGS_DEBUG "-std=c99 -O0 -g3 -Wall -Wextra -DLUA_COMPAT_5_2 -DLUA_USE_MACOSX")
     set(CMAKE_C_FLAGS_RELEASE "-std=c99 -O3 -Wall -Wextra -DLUA_COMPAT_5_2 -DLUA_USE_MACOSX")
@@ -167,6 +167,27 @@ if (LLVM_JIT)
     if (${LLVM_PACKAGE_VERSION} VERSION_LESS "3.8")
         set(LLVM_EXTRA_LIBS ipa)
     endif()
+    message(STATUS "SYSTEM_PROCESSOR ${CMAKE_SYSTEM_PROCESSOR}")
+    if (CMAKE_SYSTEM_PROCESSOR MATCHES "(x86)|(X86)|(amd64)|(AMD64)")
+	set(LLVM_LIBS_PROCESSOR
+		X86CodeGen
+		X86AsmParser
+		X86Disassembler
+		X86AsmPrinter
+		X86Desc
+		X86Info
+		X86Utils
+	    )
+    elseif (CMAKE_SYSTEM_PROCESSOR MATCHES "arm")
+	set(LLVM_LIBS_PROCESSOR
+		ARMCodeGen
+		ARMAsmParser
+		ARMDisassembler
+		ARMAsmPrinter
+		ARMDesc
+		ARMInfo
+	    )
+    endif()
     llvm_map_components_to_libnames(LLVM_LIBS
             Analysis
             Core
@@ -187,13 +208,7 @@ if (LLVM_JIT)
             Support
             Target
             TransformUtils
-            X86CodeGen
-            X86AsmParser
-            X86Disassembler
-            X86AsmPrinter
-            X86Desc
-            X86Info
-            X86Utils
+	    ${LLVM_LIBS_PROCESSOR}
             )
     message(STATUS "LLVM_LIBS ${LLVM_LIBS}")
 endif ()

include/ravi_llvmcodegen.h

@@ -62,7 +62,6 @@ extern "C" {
 #endif
 
 #include <array>
-#include <atomic>
 #include <iterator>
 #include <type_traits>
 

src/ravi_llvmjit.cpp

@@ -45,8 +45,22 @@ LUA_API int ravi_get_modulecount() {
 namespace ravi {
 
 // This is just to avoid initializing LLVM repeatedly -
-// see below
-static std::atomic_int init;
+// LLVM needs to be initialized else
+// ExecutionEngine cannot be created
+// This needs to be an atomic check although LLVM docs
+// say that it is okay to call these functions more than once
+struct Ravi_LLVM_Initializer
+{
+    bool llvm_already_initialized;
+    Ravi_LLVM_Initializer()
+    {
+        llvm::InitializeNativeTarget();
+        llvm::InitializeNativeTargetAsmPrinter();
+        llvm::InitializeNativeTargetAsmParser();
+        llvm_already_initialized = true;
+    }
+};
+static Ravi_LLVM_Initializer ravi_llvm_initializer;
 
 // Construct the JIT compiler state
 // The JIT compiler state will be attached to the
@@ -61,16 +75,6 @@ RaviJITState::RaviJITState()
       min_exec_count_(50),
       gc_step_(200),
       tracehook_enabled_(false) {
-  // LLVM needs to be initialized else
-  // ExecutionEngine cannot be created
-  // This needs to be an atomic check although LLVM docs
-  // say that it is okay to call these functions more than once
-  if (init == 0) {
-    llvm::InitializeNativeTarget();
-    llvm::InitializeNativeTargetAsmPrinter();
-    llvm::InitializeNativeTargetAsmParser();
-    init++;
-  }
   triple_ = llvm::sys::getProcessTriple();
 #if defined(_WIN32) && (!defined(_WIN64) || LLVM_VERSION_MINOR < 7)
   // On Windows we get compilation error saying incompatible object format
@@ -96,14 +100,10 @@ void RaviJITState::addGlobalSymbol(const std::string &name, void *address) {
 
 void RaviJITState::dump() { types_->dump(); }
 
-static std::atomic_int module_id;
-
-
 RaviJITModule::RaviJITModule(RaviJITState *owner)
     : owner_(owner), engine_(nullptr), module_(nullptr) {
-  int myid = module_id++;
   char buf[40];
-  snprintf(buf, sizeof buf, "ravi_module_%d", myid);
+  snprintf(buf, sizeof buf, "ravi_module_%p", this);
   std::string moduleName(buf);
   module_ = new llvm::Module(moduleName, owner->context());
 #if defined(_WIN32) && (!defined(_WIN64) || LLVM_VERSION_MINOR < 7)