早上在用protobuf和grpc时遇到了报错：
g++ -Wno-expansion-to-defined -Wno-implicit-fallthrough -std=c++11 `pkg-config --cflags protobuf grpc` -c -o helloworld.grpc.pb.o helloworld.grpc.pb.cc
In file included from helloworld.grpc.pb.cc:5:0:
helloworld.pb.h:17:2: error: #error This file was generated by an older version of protoc which is
#error This file was generated by an older version of protoc which is
^~~~~
helloworld.pb.h:18:2: error: #error incompatible with your Protocol Buffer headers. Please
#error incompatible with your Protocol Buffer headers. Please
^~~~~
helloworld.pb.h:19:2: error: #error regenerate this file with a newer version of protoc.
#error regenerate this file with a newer version of protoc.
^~~~~
In file included from helloworld.grpc.pb.cc:5:0:
helloworld.pb.h: In member function ‘const string& helloworld::HelloRequest::name() const’:
helloworld.pb.h:230:87: error: no matching function for call to ‘google::protobuf::internal::ArenaStringPtr::GetNoArena(const string*) const’
return name_.GetNoArena(&::google::protobuf::internal::GetEmptyStringAlreadyInited());
....
helloworld.grpc.pb.cc:35:127: error: expected primary-expression before ‘const’
ncResponseReader< ::helloworld::HelloReply>* Greeter::Stub::AsyncSayHelloRaw(::grpc::ClientContext* context, const ::helloworld::HelloRequest& request, ::grpc::CompletionQueue* cq) {
^~~~~
helloworld.grpc.pb.cc:35:193: error: expected primary-expression before ‘*’ token
yncSayHelloRaw(::grpc::ClientContext* context, const ::helloworld::HelloRequest& request, ::grpc::CompletionQueue* cq) {
^
helloworld.grpc.pb.cc:35:195: error: ‘cq’ was not declared in this scope
yncSayHelloRaw(::grpc::ClientContext* context, const ::helloworld::HelloRequest& request, ::grpc::CompletionQueue* cq) {
^~
helloworld.grpc.pb.cc:35:197: error: expression list treated as compound expression in initializer [-fpermissive]
yncSayHelloRaw(::grpc::ClientContext* context, const ::helloworld::HelloRequest& request, ::grpc::CompletionQueue* cq) {
^
helloworld.grpc.pb.cc: In constructor ‘helloworld::Greeter::Service::Service()’:
helloworld.grpc.pb.cc:40:17: error: expected type-specifier before ‘::’ token
AddMethod(new ::grpc::RpcServiceMethod(
^~
<builtin>: recipe for target 'helloworld.grpc.pb.o' failed
make: *** [helloworld.grpc.pb.o] Error 1
这个报错的原因是系统上存在多个版本的protoc
我的系统上安装了2个版本的protoc
一个通过apt安装的：
apt install libprotobuf-dev protobuf-compiler-grpc
另一个是编译源码安装的，版本不同造成了冲突。
解决方法是卸载：
apt remove libprotobuf-dev protobuf-compiler-grpc
apt autoremove
如果还有问题，查看系统中是否存在其他的包产生冲突。
实在解决不了就重装系统。
关于grpc与protobuf的安装和使用，参考这篇博客：grpc与protobuf最佳实践
文档信息
- 本文作者：last2win
- 本文链接：https://last2win.com/2020/03/01/protoc-error/
- 版权声明：自由转载-非商用-非衍生-保持署名（创意共享3.0许可证）