fatal error: 'grpcpp/grpcpp.h' file not found C++ - c++

Question

Context
I have been working with C++ for about the past 5-6 months and I'm beginning to learn gRPC. I have followed many tutorials online to get started, but I want to build a client-server communication app from scratch. Probably a bit too much, but I'm doing my best to understand how to get it all to work from the ground up rather than downloading, typing 'make', and then having a working product that I don't know how to implement into my own projects.
Goal: Create and run a simple C++ gRPC client-server communication
Versions
Using VSCode IDE.
Protoc = libprotoc 3.17.3
gRPC = 1.41.1
make = 3.81
Files
mathtest.proto
syntax = "proto3";
option java_package = "ex.grpc";
package mathtest;
// Defines the service
service MathTest {
// Function invoked to send the request
rpc sendRequest (MathRequest) returns (MathReply) {}
}
// The request message containing requested numbers
message MathRequest {
int32 a = 1;
int32 b = 2;
}
// The response message containing response
message MathReply {
int32 result = 1;
}
server.cpp
#include <string>
#include <grpcpp/grpcpp.h>
#include "mathtest.grpc.pb.h"
using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::Status;
using mathtest::MathTest;
using mathtest::MathRequest;
using mathtest::MathReply;
class MathServiceImplementation final : public MathTest::Service {
Status sendRequest(
ServerContext* context,
const MathRequest* request,
MathReply* reply
) override {
int a = request->a();
int b = request->b();
reply->set_result(a * b);
return Status::OK;
}
};
void Run() {
std::string address("0.0.0.0:5000");
MathServiceImplementation service;
ServerBuilder builder;
builder.AddListeningPort(address, grpc::InsecureServerCredentials());
builder.RegisterService(&service);
std::unique_ptr<Server> server(builder.BuildAndStart());
std::cout << "Server listening on port: " << address << std::endl;
server->Wait();
}
int main(int argc, char** argv) {
Run();
return 0;
}
client.cpp
#include <string>
#include <grpcpp/grpcpp.h>
#include "mathtest.grpc.pb.h"
using grpc::Channel;
using grpc::ClientContext;
using grpc::Status;
using mathtest::MathTest;
using mathtest::MathRequest;
using mathtest::MathReply;
class MathTestClient {
public:
MathTestClient(std::shared_ptr<Channel> channel) : stub_(MathTest::NewStub(channel)) {}
int sendRequest(int a, int b) {
MathRequest request;
request.set_a(a);
request.set_b(b);
MathReply reply;
ClientContext context;
Status status = stub_->sendRequest(&context, request, &reply);
if(status.ok()){
return reply.result();
} else {
std::cout << status.error_code() << ": " << status.error_message() << std::endl;
return -1;
}
}
private:
std::unique_ptr<MathTest::Stub> stub_;
};
void Run() {
std::string address("0.0.0.0:5000");
MathTestClient client(
grpc::CreateChannel(
address,
grpc::InsecureChannelCredentials()
)
);
int response;
int a = 5;
int b = 10;
response = client.sendRequest(a, b);
std::cout << "Answer received: " << a << " * " << b << " = " << response << std::endl;
}
int main(int argc, char* argv[]){
Run();
return 0;
}
Steps taken for compilation
Use mathtest.proto to create the necessary files via 'protoc' (or protobuf) by executing these: protoc --grpc_out=. --plugin=protoc-gen-grpc=/opt/homebrew/bin/grpc_cpp_plugin mathtest.proto & protoc --cpp_out=. mathtest.proto
This creates the following files:
mathtest.pb.h
mathtest.pb.cc
mathtest.grpc.pb.h
mathtest.grpc.pb.cc
Compile client.cpp & server.cpp files to create executable binaries using these commands: g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client 'pkg-config --libs protobuf grpc++' (NOTE: in this post, I use a single quote in the command line, but in the actual command I use a backtick; just wanted to make that clear)
Errors
As you may notice, I can't get to compiling the server because I can't get past the client compilation first. After executing the above command in step 2 of compilation, this is my output:
g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client `pkg-config --libs protobuf grpc++`
client.cpp:4:10: fatal error: 'grpcpp/grpcpp.h' file not found
#include <grpcpp/grpcpp.h>
^~~~~~~~~~~~~~~~~
1 error generated.
In file included from mathtest.pb.cc:4:
./mathtest.pb.h:10:10: fatal error: 'google/protobuf/port_def.inc' file not found
#include <google/protobuf/port_def.inc>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
In file included from mathtest.grpc.pb.cc:5:
./mathtest.pb.h:10:10: fatal error: 'google/protobuf/port_def.inc' file not found
#include <google/protobuf/port_def.inc>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make: *** [client] Error 1
Here's my real confusion...
C++ intellisense has no issues finding these files. My $PATH variables point to these folders, and my VS Code include path also point to these folders. I'm unsure where I am going wrong here...
echo $PATH returns this:
/opt/homebrew/bin:/opt/homebrew/sbin:/opt/homebrew/include:/opt/homebrew/Cellar:/opt/homebrew/opt/libtool/libexec/gnubin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/tzeller/.local/bin
The folders in question ('google' & 'grcpp') live within /opt/homebrew/include and they hold the necessary files as well...
What am I missing??

Answer 1

Change your compile command to
g++ -std=c++17 client.cpp mathtest.pb.cc mathtest.grpc.pb.cc -o client `pkg-config --libs --cflags protobuf grpc++`
The --cflags bit asks pkg-config to spit out the necessary parameters for setting the header search path (on my system -I/opt/homebrew/Cellar/grpc/1.41.1/include and others)