/**
* This function creates a module constructor function to create the
* map from function keys to function names. This function will be
* automatically called when the module is loaded.
*
* The code was generated by using clang on a test file. The test
* file looked like (foo.cc):
* __attribute__((constructor))
* static void init()
* {
* }
*
* Then, run:
* 1. clang -S -emit-llvm -c foo.cc
* 2. llc -march=cpp foo.bc -o foo.lc
* The output foo.lc provides code for generating a ctor using LLVM.
*
*/
void BytesFlops::initializeKeyMap(Module& module)
{
if ( module.getFunction("func_key_map_ctor") )
return;
LLVMContext& ctx = module.getContext();
// Type Definitions
std::vector<Type*>StructTy_1_fields;
StructTy_1_fields.push_back(IntegerType::get(ctx, 32));
std::vector<Type*>FuncTy_3_args;
FunctionType* FuncTy_3 = FunctionType::get(
/*Result=*/ Type::getVoidTy(ctx),
/*Params=*/ FuncTy_3_args,
/*isVarArg=*/ false);
PointerType* PointerTy_2 = PointerType::get(FuncTy_3, 0);
StructTy_1_fields.push_back(PointerTy_2);
StructType *
StructTy_1 = StructType::get(ctx, StructTy_1_fields,
/*isPacked=*/false);
ArrayType* ArrayTy_0 = NULL;
// Function Declarations
func_map_ctor = Function::Create(
/*Type=*/FuncTy_3,
/*Linkage=*/GlobalValue::InternalLinkage,
/*Name=*/"func_key_map_ctor", &module);
func_map_ctor->setCallingConv(CallingConv::C);
AttributeSet func__ZL4initv_PAL;
SmallVector<AttributeSet, 4> Attrs;
AttributeSet PAS;
AttrBuilder B;
B.addAttribute(Attribute::NoUnwind);
B.addAttribute(Attribute::UWTable);
PAS = AttributeSet::get(ctx, ~0U, B);
Attrs.push_back(PAS);
func__ZL4initv_PAL = AttributeSet::get(ctx, Attrs);
func_map_ctor->setAttributes(func__ZL4initv_PAL);
// Global Variable Declarations
// Constant Definitions
std::vector<Constant*> ctor_elems;
std::vector<Constant*> const_struct_8_fields;
ConstantInt* const_int32_9 = ConstantInt::get(ctx, APInt(32, StringRef("65535"), 10));
const_struct_8_fields.push_back(const_int32_9);
const_struct_8_fields.push_back(func_map_ctor);
Constant* const_struct_8 = ConstantStruct::get(StructTy_1, const_struct_8_fields);
ctor_elems.push_back(const_struct_8);
GlobalVariable* llvm_global_ctors;
/**
* Add our constructor to the list of global constructors for the
* module. It's possible that a module already contains a ctor.
*/
GlobalVariable*
current_ctors = module.getGlobalVariable("llvm.global_ctors");
if ( !current_ctors )
{
ArrayTy_0 = ArrayType::get(StructTy_1, 1);
}
else
{
// there are existing ctors, and the initializer points to them.
// add ours to the initializer list (actually, we create a new
// initializer list and add the existing ones to it).
Constant * initializer = current_ctors->getInitializer();
ConstantArray *
ar = llvm::dyn_cast<ConstantArray>(initializer);
assert( ar );
int cnt = 0;
Constant *
elt = ar->getAggregateElement(cnt);
// add existing ctors to new initializer list, and get rid
// of the old one.
while ( elt )
{
assert( llvm::dyn_cast<ConstantStruct>(elt) );
ctor_elems.push_back(elt);
cnt++;
elt = ar->getAggregateElement(cnt);
}
ArrayTy_0 = ArrayType::get(StructTy_1, ctor_elems.size());
current_ctors->eraseFromParent();
}
llvm_global_ctors = new GlobalVariable(/*Module=*/module,
/*Type=*/ ArrayTy_0,
/*isConstant=*/ false,
/*Linkage=*/ GlobalValue::AppendingLinkage,
/*Initializer=*/0, // has initializer, specified below
/*Name=*/ "llvm.global_ctors");
Constant* ctor_array = ConstantArray::get(ArrayTy_0, ctor_elems);
// Global Variable Definitions
llvm_global_ctors->setInitializer(ctor_array);
}
