issue #126 add a couple of simple hello world examples

include/ravi_llvmcodegen.h

@@ -468,6 +468,9 @@ class RaviJITFunction {
                   llvm::FunctionType *type,
                   llvm::GlobalValue::LinkageTypes linkage,
                   const std::string &name);
+  RaviJITFunction(lua_CFunction *p, std::shared_ptr<RaviJITModule> module,      
+      const std::string &name);
+
   ~RaviJITFunction();
 
   const std::string &name() const { return name_; }

ravi-tests/dmrc_getsymbols.lua

@@ -0,0 +1,38 @@
+-- Print anything - including nested tables
+local function table_print (tt, indent, done)
+  done = done or {}
+  indent = indent or 0
+  if type(tt) == "table" then
+    for key, value in pairs (tt) do
+      io.write(string.rep (" ", indent)) -- indent it
+      if type (value) == "table" and not done [value] then
+        done [value] = true
+        io.write(string.format("[%s] => table\n", tostring (key)));
+        io.write(string.rep (" ", indent+4)) -- indent it
+        io.write("(\n");
+        table_print (value, indent + 7, done)
+        io.write(string.rep (" ", indent+4)) -- indent it
+        io.write(")\n");
+      else
+        io.write(string.format("[%s] => %s\n",
+          tostring (key), tostring(value)))
+      end
+    end
+  else
+    io.write(tostring(tt) .. "\n")
+  end
+end
+
+
+local somecode = [[
+extern int adder(int a, int b);
+
+int adder(int a, int b)
+{
+	return a+b;
+}
+]]
+
+local symbols = dmrc.getsymbols(somecode)
+
+table_print(symbols)

ravi-tests/dmrc_test.lua

@@ -0,0 +1,20 @@
+local testfunc = [[
+struct lua_State;
+extern int puts(const char *);
+extern int TestFunc(struct lua_State *L);
+
+int TestFunc(struct lua_State *L) 
+{
+	puts("hello world!\n");
+	return 0;
+}
+]]
+
+
+local ctx = llvm.context()
+local m = ctx:newmodule()
+m:compileC(testfunc)
+local f = m:getfunction("TestFunc")
+local callable = f:compile()
+
+callable()

src/ravi_llvmjit.cpp

@@ -130,8 +130,8 @@ RaviJITState::RaviJITState()
     llvm::InitializeNativeTarget();
     llvm::InitializeNativeTargetAsmPrinter();
     llvm::InitializeNativeTargetAsmParser();
-    //TODO see email trail on resolving symbols in process
-    //llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
+    // TODO see email trail on resolving symbols in process
+    // llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
     init++;
   }
   triple_ = llvm::sys::getProcessTriple();
@@ -233,7 +233,7 @@ RaviJITModule::~RaviJITModule() {
     delete module_;
   owner_->decr_allocated_modules();
 #if 1
-  //fprintf(stderr, "module destroyed\n");
+// fprintf(stderr, "module destroyed\n");
 #endif
 }
 
@@ -262,6 +262,14 @@ RaviJITFunction::RaviJITFunction(lua_CFunction *p,
   id_ = module_->addFunction(this);
 }
 
+RaviJITFunction::RaviJITFunction(lua_CFunction *p,
+                                 std::shared_ptr<RaviJITModule> module,
+                                 const std::string &name)
+    : module_(module), name_(name), ptr_(nullptr), func_ptrptr_(p) {
+  function_ = module_->module()->getFunction(name);
+  id_ = module_->addFunction(this);
+}
+
 RaviJITFunction::~RaviJITFunction() {
   // Remove this function from parent
   // fprintf(stderr, "function destroyed\n");
@@ -387,8 +395,12 @@ void RaviJITModule::finalize(bool doDump) {
 // Lua Proto structure
 void RaviJITFunction::setFunctionPtr() {
   lua_assert(ptr_ == nullptr);
-  ptr_ = engine()->getPointerToFunction(function_);
-  *func_ptrptr_ = (lua_CFunction)ptr_;
+  // function_ may be nullptr if it was obtained by name from the module, so
+  // we need to check that
+  if (function_) {
+    ptr_ = engine()->getPointerToFunction(function_);
+    *func_ptrptr_ = (lua_CFunction)ptr_;
+  }
 }
 
 llvm::Function *RaviJITModule::addExternFunction(llvm::FunctionType *type,

src/ravi_llvmluaapi.cpp

@@ -240,7 +240,7 @@ static void alloc_LLVM_module(lua_State *L,
 /* __gc for ModuleHolder */
 static int collect_LLVM_module(lua_State *L) {
   ModuleHolder *mh = check_LLVM_module(L, 1);
-  //printf("Module released: usecount %d\n", (int)mh->M.use_count());
+  // printf("Module released: usecount %d\n", (int)mh->M.use_count());
   mh->~ModuleHolder();
   return 0;
 }
@@ -321,6 +321,7 @@ static void alloc_LLVM_phinode(lua_State *L, llvm::PHINode *phi) {
   h->phi = phi;
 }
 
+// Creates a new module to hold a Lua C Function
 static MainFunctionHolder *alloc_LLVM_mainfunction(lua_State *L,
                                                    ravi::RaviJITState *jit,
                                                    llvm::FunctionType *type,
@@ -338,13 +339,28 @@ static MainFunctionHolder *alloc_LLVM_mainfunction(lua_State *L,
   return h;
 }
 
+// References an existing function in a Module
+static MainFunctionHolder *alloc_LLVM_luaCfunction(
+    lua_State *L, std::shared_ptr<ravi::RaviJITModule> module,
+    const char *name) {
+  MainFunctionHolder *h =
+      (MainFunctionHolder *)lua_newuserdata(L, sizeof(MainFunctionHolder));
+  h->func = nullptr;
+  h->compiled_func = nullptr;
+  h->arg1 = nullptr;
+  raviL_getmetatable(L, LLVM_mainfunction);
+  lua_setmetatable(L, -2);
+  h->func = new ravi::RaviJITFunction(&h->compiled_func, module, name);
+  return h;
+}
+
 /* __gc for FunctionHolder */
 static int collect_LLVM_mainfunction(lua_State *L) {
   MainFunctionHolder *builder = check_LLVM_mainfunction(L, 1);
   if (builder->func) {
     delete builder->func;
     builder->func = nullptr;
-    //printf("collected function\n");
+    // printf("collected function\n");
   }
   return 0;
 }
@@ -655,6 +671,14 @@ static int module_newfunction(lua_State *L) {
   return 1;
 }
 
+static int module_getfunction(lua_State *L) {
+  ModuleHolder *mh = check_LLVM_module(L, 1);
+  const char *name = luaL_checkstring(L, 2);
+  alloc_LLVM_luaCfunction(L, mh->M, name);
+  // TODO we should check that the function signature is correct
+  return 1;
+}
+
 static int module_compile_C(lua_State *L) {
   ModuleHolder *mh = check_LLVM_module(L, 1);
   const char *codebuffer = luaL_checkstring(L, 2);
@@ -674,13 +698,12 @@ static int module_compile_C(lua_State *L) {
 }
 
 static int module_generate_code(lua_State *L) {
-    ModuleHolder *mh = check_LLVM_module(L, 1);
-    mh->M->runpasses();
-    mh->M->finalize();
-    return 0;
+  ModuleHolder *mh = check_LLVM_module(L, 1);
+  mh->M->runpasses();
+  mh->M->finalize();
+  return 0;
 }
 
-
 static int context_new_basicblock(lua_State *L) {
   ContextHolder *context = check_LLVM_context(L, 1);
   const char *name = luaL_checkstring(L, 2);
@@ -744,6 +767,7 @@ static int irbuilder_condbranch(lua_State *L) {
 
 static int func_compile(lua_State *L) {
   MainFunctionHolder *f = check_LLVM_mainfunction(L, 1);
+  if (!f->func->function()) return 0;
   if (!f->compiled_func) {
     f->func->raviModule()->runpasses();
     f->func->raviModule()->finalize();
@@ -1255,11 +1279,10 @@ static const luaL_Reg llvmlib[] = {
 static const luaL_Reg structtype_methods[] = {{"setbody", struct_add_members},
                                               {NULL, NULL}};
 
-static const luaL_Reg module_methods[] = {{"newfunction", module_newfunction},
-                                          {"compileC", module_compile_C},
-                                          {"dump", dump_content},
-                                          {"generatecode", module_generate_code},
-                                          {NULL, NULL}};
+static const luaL_Reg module_methods[] = {
+    {"newfunction", module_newfunction},    {"getfunction", module_getfunction},
+    {"compileC", module_compile_C},         {"dump", dump_content},
+    {"generatecode", module_generate_code}, {NULL, NULL}};
 
 static const luaL_Reg main_function_methods[] = {
     {"appendblock", func_append_basicblock},