求助llvm：新建AllocaInst类报错的问题

[cs1612900]

这是出错的代码部分
AllocaInst *alloc = new AllocaInst(typeOf(type), id.name.c_str(), "", context.currentBlock());
报错内容是 id.name.c_str()，const char*类型不能转为unsingned int
构造函数是这样的，
AllocaInst::AllocaInst ( Type * Ty,
unsigned AddrSpace,
const Twine & Name,
BasicBlock * InsertAtEnd
)
，但是其他的如 llvm::Function::Create ( FunctionType * Ty,
LinkageTypes Linkage,
unsigned AddrSpace,
const Twine & N = "",
Module * M = nullptr
)
在第三个参数位置使用同样的函数却没有报这样的错误
报错信息是这样的
codegen.cpp:171:64: error: invalid conversion from ‘const char*’ to ‘unsigned int’ [-fpermissive]
AllocaInst *alloc = new AllocaInst(typeOf(type), id.name.c_str(), "", context.
^
In file included from codegen.h:9:0,
from codegen.cpp:2:
/home/xingwj/LLVM/include/llvm/IR/Instructions.h:79:3: note: initializing argument 2 of ‘llvm::AllocaInst::AllocaInst(llvm::Type*, unsigned int, const llvm::Twine&, llvm::BasicBlock*)’
AllocaInst(Type *Ty, unsigned AddrSpace,
^
Makefile:27: recipe for target 'codegen.o' failed
make: *** [codegen.o] Error 1

跪求大佬指导