Possible duplicate:
C code compiles as C ++, but not as C
Edit:
I recompiled the source for the library as C and fixed it.
I have this code that I need to use in my application. This is for writing to the serial port, and I can’t figure out how to make it work in C. I have a version in C ++, as well as a version that is more like C, designed to compile with Borland C ++ 5.5, but I cannot compile it there or in my project.
Edit: I have to note that it compiles (and links) when compiling as C ++, but not when I compile as c.
Here is the linker error:
1>InpoutTest.obj : error LNK2019: unresolved external symbol _Out32@8 referenced in function _main 1>InpoutTest.obj : error LNK2019: unresolved external symbol _Inp32@4 referenced in function _main
Here is the C ++ code. I don't need command line functionality, I just need to be able to call Out32 (). I don’t even have to read.
#include "stdafx.h" #include "stdio.h" #include "string.h" #include "stdlib.h" /* ----Prototypes of Inp and Outp--- */ short _stdcall Inp32(short PortAddress); void _stdcall Out32(short PortAddress, short data); /*--------------------------------*/ int main(int argc, char* argv[]) { int data; if(argc<3) { //too few command line arguments, show usage printf("Error : too few arguments\n\n***** Usage *****\n\nInpoutTest read <ADDRESS> \nor \nInpoutTest write <ADDRESS> <DATA>\n\n\n\n\n"); } else if(!strcmp(argv[1],"read")) { data = Inp32(atoi(argv[2])); printf("Data read from address %s is %d \n\n\n\n",argv[2],data); } else if(!strcmp(argv[1],"write")) { if(argc<4) { printf("Error in arguments supplied"); printf("\n***** Usage *****\n\nInpoutTest read <ADDRESS> \nor \nInpoutTest write <ADDRESS> <DATA>\n\n\n\n\n"); } else { Out32(atoi(argv[2]),atoi(argv[3])); printf("data written to %s\n\n\n",argv[2]); } } return 0; }
Here is another example:
#include <stdio.h> #include <conio.h> #include <windows.h> /* Definitions in the build of inpout32.dll are: */ /* short _stdcall Inp32(short PortAddress); */ /* void _stdcall Out32(short PortAddress, short data); */ /* prototype (function typedef) for DLL function Inp32: */ typedef short _stdcall (*inpfuncPtr)(short portaddr); typedef void _stdcall (*oupfuncPtr)(short portaddr, short datum); int main(void) { HINSTANCE hLib; inpfuncPtr inp32; oupfuncPtr oup32; short x; int i; /* Load the library */ hLib = LoadLibrary("inpout32.dll"); if (hLib == NULL) { printf("LoadLibrary Failed.\n"); return -1; } /* get the address of the function */ inp32 = (inpfuncPtr) GetProcAddress(hLib, "Inp32"); if (inp32 == NULL) { printf("GetProcAddress for Inp32 Failed.\n"); return -1; } oup32 = (oupfuncPtr) GetProcAddress(hLib, "Out32"); if (oup32 == NULL) { printf("GetProcAddress for Oup32 Failed.\n"); return -1; } /***************************************************************/ /* now test the functions */ /* Try to read 0x378..0x37F, LPT1: */ for (i=0x378; (i<0x380); i++) { x = (inp32)(i); printf("port read (%04X)= %04X\n",i,x); } /***** Write the data register */ i=0x378; x=0x77; (oup32)(i,x); printf("port write to 0x%X, datum=0x%2X\n" ,i ,x); /***** And read back to verify */ x = (inp32)(i); printf("port read (%04X)= %04X\n",i,x); /***** One more time, different value */ i=0x378; x=0xAA; (oup32)(i,x); printf("port write to 0x%X, datum=0x%2X\n" ,i ,x); /***** And read back to verify */ x = (inp32)(i); printf("port read (%04X)= %04X\n",i,x); FreeLibrary(hLib); return 0; }
Any help would be appreciated.