c - mpi 编译警告隐式声明

Question

今天我在 mi mac 10.9 上安装了 mpi 和 home-brew mpicc 与 simlpe hello world 程序一起工作，但是如果我尝试这样的事情

#include <mpi.h>
#include <string.h>
#include <stdio.h>
#define max 1000

int main(int argv, char *argc[]){


    int myrank,nProc,tag,j;
    char buff [max];
    MPI_Status status;
    tag=0;
    MPI_Init(&argv,&argc);
    MPI_Comm_Rank(MPI_COMM_WORLD,&myrank);
    MPI_Comm_Size(MPI_COMM_WORLD,&nProc);

    if(myrank==0){
    for(j =1 ; j<nProc;j++){
    MPI_Recv(&buff,max,MPI_CHAR,j,tag,MPI_COMM_WORLD,&status);
    printf("Il processo %d dice di chiamarsi %s\n",j,buff);
    }

                }
                else{
                switch (myrank){
                case 1 :
                 MPI_Send("Franco",max,MPI_CHAR,j,tag,MPI_COMM_WORLD);
                 break;
                 case 2 :
                 MPI_Send("Mena",max,MPI_CHAR,j,tag,MPI_COMM_WORLD);
                 break;
                 case 3 :
                 MPI_Send("Nino",max,MPI_CHAR,j,tag,MPI_COMM_WORLD);
                 break;
                                }
                    }
    printf("Ciao da %d \n",myrank);
    MPI_Finalize();
    return(0);
                               }

然后我尝试编译它的下一行:

mpicc -o filename filename.c

它给了我这个警告但没有构建。

nucciampi.c:15:3: warning: implicit declaration of function 'MPI_Comm_Rank' is
      invalid in C99 [-Wimplicit-function-declaration]
                MPI_Comm_Rank(MPI_COMM_WORLD,&myrank);
                ^
nucciampi.c:16:3: warning: implicit declaration of function 'MPI_Comm_Size' is
      invalid in C99 [-Wimplicit-function-declaration]
                MPI_Comm_Size(MPI_COMM_WORLD,&nProc);
                ^
2 warnings generated.
Undefined symbols for architecture x86_64:
  "_MPI_Comm_Rank", referenced from:
      _main in nucciampi-zsehoq.o
  "_MPI_Comm_Size", referenced from:
      _main in nucciampi-zsehoq.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

请帮我解决这个问题!!!

Answer 1

MPI_Comm_Rank -> MPI_Comm_rank

MPI_Comm_Size -> MPI_Comm_size