I have a function that takes as parameter an unique_ptr of cctx and EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY mode. When I call these two init_pkey_ctx functions from constructor, I get following symbol error.
symbol lookup error: libkerf.code.so: undefined symbol: EVP_PKEY_CTX_set_hkdf_mode
I have the following piece of code:
NCF_SYMBOL_VISIBLE kerf_decryptor():
cctx(EVP_CIPHER_CTX_new(), &EVP_CIPHER_CTX_free),
pctx_extract(EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, nullptr), &EVP_PKEY_CTX_free),
pctx_expand(EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, nullptr), &EVP_PKEY_CTX_free)
{
if (!cctx || !pctx_expand || !pctx_extract)
NCF_LOG_ERROR(acu_event_id::sei_cl_mod_code_classify_kerf_fail_decryption, "Initializing the kerf_decryptor: EVP_CIPHER_CTX_new");
init_pkey_ctx(pctx_extract.get(),EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY);
init_pkey_ctx(pctx_expand.get(), EVP_PKEY_HKDEF_MODE_EXPAND_ONLY);
}
//initialize pkey(the source of error)
void init_pkey_ctx(EVP_PKEY_CTX *ctx, std::int32_t mode)
{
if (EVP_PKEY_derive_init(ctx) <= 0) {
NCF_LOG_ERROR(acu_event_id::sei_cl_mod_code_classify_kerf_fail_decryption, "EVP_PKEY_derive_init");
}
if (EVP_PKEY_CTX_set_hkdf_mode(ctx, mode) <= 0){
NCF_LOG_ERROR(acu_event_id::sei_cl_mod_code_classify_kerf_fail_decryption, "EVP_PKEY_CTX_set_hkdf_mode");
}
if (EVP_PKEY_CTX_set_hkdf_md(ctx, EVP_sha256()) <= 0){
NCF_LOG_ERROR(acu_event_id::sei_cl_mod_code_classify_kerf_fail_decryption, "EVP_PKEY_CTX_set_hkdf_md");
}
}
std::unique_ptr<EVP_CIPHER_CTX, decltype(&EVP_CIPHER_CTX_free)> cctx;
std::unique_ptr<EVP_PKEY_CTX, decltype(&EVP_PKEY_CTX_free)> pctx_extract;
std::unique_ptr<EVP_PKEY_CTX, decltype(&EVP_PKEY_CTX_free)> pctx_expand;
I want to have a way to report the stack trace to the user if an exception is thrown. What is the best way to do this? Does it take huge amounts of extra code?
To answer questions:
I'd like it to be portable if possible. I want information to pop up, so the user can copy the stack trace and email it to me if an error comes up.
Andrew Grant's answer does not help getting a stack trace of the throwing function, at least not with GCC, because a throw statement does not save the current stack trace on its own, and the catch handler won't have access to the stack trace at that point any more.
The only way - using GCC - to solve this is to make sure to generate a stack trace at the point of the throw instruction, and save that with the exception object.
This method requires, of course, that every code that throws an exception uses that particular Exception class.
Update 11 July 2017: For some helpful code, take a look at cahit beyaz's answer, which points to http://stacktrace.sourceforge.net - I haven't used it yet but it looks promising.
It depends which platform.
On GCC it's pretty trivial, see this post for more details.
On MSVC then you can use the StackWalker library that handles all of the underlying API calls needed for Windows.
You'll have to figure out the best way to integrate this functionality into your app, but the amount of code you need to write should be minimal.
If you are using Boost 1.65 or higher, you can use boost::stacktrace:
#include <boost/stacktrace.hpp>
// ... somewhere inside the bar(int) function that is called recursively:
std::cout << boost::stacktrace::stacktrace();
I would like to add a standard library option (i.e. cross-platform) how to generate exception backtraces, which has become available with C++11:
Use std::nested_exception and std::throw_with_nested
This won't give you a stack unwind, but in my opinion the next best thing.
It is described on StackOverflow here and here, how you can get a backtrace on your exceptions inside your code without need for a debugger or cumbersome logging, by simply writing a proper exception handler which will rethrow nested exceptions.
Since you can do this with any derived exception class, you can add a lot of information to such a backtrace!
You may also take a look at my MWE on GitHub, where a backtrace would look something like this:
Library API: Exception caught in function 'api_function'
Backtrace:
~/Git/mwe-cpp-exception/src/detail/Library.cpp:17 : library_function failed
~/Git/mwe-cpp-exception/src/detail/Library.cpp:13 : could not open file "nonexistent.txt"
Unix: backtrace
Mac: backtrace
Windows: CaptureBackTrace
If you are using C++ and don't want/can't use Boost, you can print backtrace with demangled names using the following code [link to the original site].
Note, this solution is specific to Linux. It uses GNU's libc functions backtrace()/backtrace_symbols() (from execinfo.h) to get the backtraces and then uses __cxa_demangle() (from cxxabi.h) for demangling the backtrace symbol names.
// stacktrace.h (c) 2008, Timo Bingmann from http://idlebox.net/
// published under the WTFPL v2.0
#ifndef _STACKTRACE_H_
#define _STACKTRACE_H_
#include <stdio.h>
#include <stdlib.h>
#include <execinfo.h>
#include <cxxabi.h>
/** Print a demangled stack backtrace of the caller function to FILE* out. */
static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames = 63)
{
fprintf(out, "stack trace:\n");
// storage array for stack trace address data
void* addrlist[max_frames+1];
// retrieve current stack addresses
int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*));
if (addrlen == 0) {
fprintf(out, " <empty, possibly corrupt>\n");
return;
}
// resolve addresses into strings containing "filename(function+address)",
// this array must be free()-ed
char** symbollist = backtrace_symbols(addrlist, addrlen);
// allocate string which will be filled with the demangled function name
size_t funcnamesize = 256;
char* funcname = (char*)malloc(funcnamesize);
// iterate over the returned symbol lines. skip the first, it is the
// address of this function.
for (int i = 1; i < addrlen; i++)
{
char *begin_name = 0, *begin_offset = 0, *end_offset = 0;
// find parentheses and +address offset surrounding the mangled name:
// ./module(function+0x15c) [0x8048a6d]
for (char *p = symbollist[i]; *p; ++p)
{
if (*p == '(')
begin_name = p;
else if (*p == '+')
begin_offset = p;
else if (*p == ')' && begin_offset) {
end_offset = p;
break;
}
}
if (begin_name && begin_offset && end_offset
&& begin_name < begin_offset)
{
*begin_name++ = '\0';
*begin_offset++ = '\0';
*end_offset = '\0';
// mangled name is now in [begin_name, begin_offset) and caller
// offset in [begin_offset, end_offset). now apply
// __cxa_demangle():
int status;
char* ret = abi::__cxa_demangle(begin_name,
funcname, &funcnamesize, &status);
if (status == 0) {
funcname = ret; // use possibly realloc()-ed string
fprintf(out, " %s : %s+%s\n",
symbollist[i], funcname, begin_offset);
}
else {
// demangling failed. Output function name as a C function with
// no arguments.
fprintf(out, " %s : %s()+%s\n",
symbollist[i], begin_name, begin_offset);
}
}
else
{
// couldn't parse the line? print the whole line.
fprintf(out, " %s\n", symbollist[i]);
}
}
free(funcname);
free(symbollist);
}
#endif // _STACKTRACE_H_
HTH!
AFAIK libunwind is quite portable and so far I haven't found anything easier to use.
I recommend http://stacktrace.sourceforge.net/ project. It support Windows, Mac OS and also Linux
Since the stack is already unwound when entering the catch block, the solution in my case was to not catch certain exceptions which then lead to a SIGABRT. In the signal handler for SIGABRT I then fork() and execl() either gdb (in debug builds) or Google breakpads stackwalk (in release builds). Also I try to only use signal handler safe functions.
GDB:
static const char BACKTRACE_START[] = "<2>--- backtrace of entire stack ---\n";
static const char BACKTRACE_STOP[] = "<2>--- backtrace finished ---\n";
static char *ltrim(char *s)
{
while (' ' == *s) {
s++;
}
return s;
}
void Backtracer::print()
{
int child_pid = ::fork();
if (child_pid == 0) {
// redirect stdout to stderr
::dup2(2, 1);
// create buffer for parent pid (2+16+1 spaces to allow up to a 64 bit hex parent pid)
char pid_buf[32];
const char* stem = " ";
const char* s = stem;
char* d = &pid_buf[0];
while (static_cast<bool>(*s))
{
*d++ = *s++;
}
*d-- = '\0';
char* hexppid = d;
// write parent pid to buffer and prefix with 0x
int ppid = getppid();
while (ppid != 0) {
*hexppid = ((ppid & 0xF) + '0');
if(*hexppid > '9') {
*hexppid += 'a' - '0' - 10;
}
--hexppid;
ppid >>= 4;
}
*hexppid-- = 'x';
*hexppid = '0';
// invoke GDB
char name_buf[512];
name_buf[::readlink("/proc/self/exe", &name_buf[0], 511)] = 0;
ssize_t r = ::write(STDERR_FILENO, &BACKTRACE_START[0], sizeof(BACKTRACE_START));
(void)r;
::execl("/usr/bin/gdb",
"/usr/bin/gdb", "--batch", "-n", "-ex", "thread apply all bt full", "-ex", "quit",
&name_buf[0], ltrim(&pid_buf[0]), nullptr);
::exit(1); // if GDB failed to start
} else if (child_pid == -1) {
::exit(1); // if forking failed
} else {
// make it work for non root users
if (0 != getuid()) {
::prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, 0, 0, 0);
}
::waitpid(child_pid, nullptr, 0);
ssize_t r = ::write(STDERR_FILENO, &BACKTRACE_STOP[0], sizeof(BACKTRACE_STOP));
(void)r;
}
}
minidump_stackwalk:
static bool dumpCallback(const google_breakpad::MinidumpDescriptor& descriptor, void* context, bool succeeded)
{
int child_pid = ::fork();
if (child_pid == 0) {
::dup2(open("/dev/null", O_WRONLY), 2); // ignore verbose output on stderr
ssize_t r = ::write(STDOUT_FILENO, &MINIDUMP_STACKWALK_START[0], sizeof(MINIDUMP_STACKWALK_START));
(void)r;
::execl("/usr/bin/minidump_stackwalk", "/usr/bin/minidump_stackwalk", descriptor.path(), "/usr/share/breakpad-syms", nullptr);
::exit(1); // if minidump_stackwalk failed to start
} else if (child_pid == -1) {
::exit(1); // if forking failed
} else {
::waitpid(child_pid, nullptr, 0);
ssize_t r = ::write(STDOUT_FILENO, &MINIDUMP_STACKWALK_STOP[0], sizeof(MINIDUMP_STACKWALK_STOP));
(void)r;
}
::remove(descriptor.path()); // this is not signal safe anymore but should still work
return succeeded;
}
Edit: To make it work for breakpad I also had to add this:
std::set_terminate([]()
{
ssize_t r = ::write(STDERR_FILENO, EXCEPTION, sizeof(EXCEPTION));
(void)r;
google_breakpad::ExceptionHandler::WriteMinidump(std::string("/tmp"), dumpCallback, NULL);
exit(1); // avoid creating a second dump by not calling std::abort
});
Source: How to get a stack trace for C++ using gcc with line number information? and Is it possible to attach gdb to a crashed process (a.k.a "just-in-time" debugging)
on linux with g++ check out this lib
https://sourceforge.net/projects/libcsdbg
it does all the work for you
On Windows, check out BugTrap. Its not longer at the original link, but its still available on CodeProject.
I have a similar problem, and though I like portability, I only need gcc support. In gcc, execinfo.h and the backtrace calls are available. To demangle the function names, Mr. Bingmann has a nice piece of code. To dump a backtrace on an exception, I create an exception that prints the backtrace in the constructor. If I were expecting this to work with an exception thrown in a library, it might require rebuilding/linking so that the backtracing exception is used.
/******************************************
#Makefile with flags for printing backtrace with function names
# compile with symbols for backtrace
CXXFLAGS=-g
# add symbols to dynamic symbol table for backtrace
LDFLAGS=-rdynamic
turducken: turducken.cc
******************************************/
#include <cstdio>
#include <stdexcept>
#include <execinfo.h>
#include "stacktrace.h" /* https://panthema.net/2008/0901-stacktrace-demangled/ */
// simple exception that prints backtrace when constructed
class btoverflow_error: public std::overflow_error
{
public:
btoverflow_error( const std::string& arg ) :
std::overflow_error( arg )
{
print_stacktrace();
};
};
void chicken(void)
{
throw btoverflow_error( "too big" );
}
void duck(void)
{
chicken();
}
void turkey(void)
{
duck();
}
int main( int argc, char *argv[])
{
try
{
turkey();
}
catch( btoverflow_error e)
{
printf( "caught exception: %s\n", e.what() );
}
}
Compiling and running this with gcc 4.8.4 yields a backtrace with nicely unmangled C++ function names:
stack trace:
./turducken : btoverflow_error::btoverflow_error(std::string const&)+0x43
./turducken : chicken()+0x48
./turducken : duck()+0x9
./turducken : turkey()+0x9
./turducken : main()+0x15
/lib/x86_64-linux-gnu/libc.so.6 : __libc_start_main()+0xf5
./turducken() [0x401629]
Poppy can gather not only the stack trace, but also parameter values, local variables, etc. - everything leading to the crash.
The following code stops the execution right after an exception is thrown. You need to set a windows_exception_handler along with a termination handler. I tested this in MinGW 32bits.
void beforeCrash(void);
static const bool SET_TERMINATE = std::set_terminate(beforeCrash);
void beforeCrash() {
__asm("int3");
}
int main(int argc, char *argv[])
{
SetUnhandledExceptionFilter(windows_exception_handler);
...
}
Check the following code for the windows_exception_handler function:
http://www.codedisqus.com/0ziVPgVPUk/exception-handling-and-stacktrace-under-windows-mingwgcc.html
Cpp-tool ex_diag - easyweight, multiplatform, minimal resource using, simple and flexible at trace.
A working example for OSX (tested right now on Catalina 10.15). Not portable to linux/windows obviously. Probably it will be usefull to somebody.
In the "Mew-exception" string you can use backtrace and/or backtrace_symbols functions
#include <stdexcept>
#include <typeinfo>
#include <dlfcn.h>
extern "C" void __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *));
static void (*__cxa_throw_orig)(void *thrown_object, std::type_info *tinfo, void (*dest)(void *));
extern "C" void luna_cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *))
{
printf("Mew-exception you can catch your backtrace here!");
__cxa_throw_orig(thrown_object, tinfo, dest);
}
//__attribute__ ((used))
//__attribute__ ((section ("__DATA,__interpose")))
static struct replace_pair_t {
void *replacement, *replacee;
} replace_pair = { (void*)luna_cxa_throw, (void*)__cxa_throw };
extern "C" const struct mach_header __dso_handle;
extern "C" void dyld_dynamic_interpose(const struct mach_header*,
const replace_pair_t replacements[],
size_t count);
int fn()
{
int a = 10; ++a;
throw std::runtime_error("Mew!");
}
int main(int argc, const char * argv[]) {
__cxa_throw_orig = (void (*)(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)))dlsym(RTLD_DEFAULT, "__cxa_throw");
dyld_dynamic_interpose(&__dso_handle, &replace_pair, 1);
fn();
return 0;
}
I'm trying to extend Python 3 using instructions given here and I'm fairly confident I've followed the instructions correctly so far, but it asks me to include this code:
PyMODINIT_FUNC
PyInit_spam(void)
{
PyObject *m;
m = PyModule_Create(&spammodule);
if (m == NULL)
return NULL;
SpamError = PyErr_NewException("spam.error", NULL, NULL);
Py_INCREF(SpamError);
PyModule_AddObject(m, "error", SpamError);
return m;
}
I'm writing this in MSVC++ 2010 and it's warning me that &spammodule is undefined (the name of the module is spammodule.cpp), but it doesn't define it anywhere in the instructions so I assume that it should recognise it automatically as the name of the module.
The full code is:
#include <Python.h>
#include <iostream>
using namespace std;
static PyObject *SpamError;
int main()
{
cout << "Test" << endl;
system("PAUSE");
return(0);
}
static PyObject *spam_system(PyObject *self, PyObject *args)
{
const char *command;
int sts;
if (!PyArg_ParseTuple(args, "s", &command))
return NULL;
sts = system(command);
return PyLong_FromLong(sts);
}
PyMODINIT_FUNC
PyInit_spam(void)
{
PyObject *m;
m = PyModule_Create(&spammodule);
if (m == NULL)
return NULL;
SpamError = PyErr_NewException("spam.error", NULL, NULL);
Py_INCREF(SpamError);
PyModule_AddObject(m, "error", SpamError);
return m;
}
You're still writing C++, so you still need to declare spammodule somewhere. This is given later on the same page:
static struct PyModuleDef spammodule = {
PyModuleDef_HEAD_INIT,
"spam", /* name of module */
spam_doc, /* module documentation, may be NULL */
-1, /* size of per-interpreter state of the module,
or -1 if the module keeps state in global variables. */
SpamMethods
};
No no no, PyModule_Create() accepts a pointer to the module definition structure and has absolutely nothing to do with the name of the source file.
I'm having a problem getting C++ code to compile properly in Netbeans, specifically code that deals with libXml2. I downloaded libXml2, put it in the include folder and I know that the code itself compiles fine without any libxml2 references in it, however, when I add the following functions:
void XmlParser::processNode(xmlTextReaderPtr reader){
const xmlChar *name, *value;
name = xmlTextReaderConstName(reader);
if (name == NULL)
name = BAD_CAST "--";
value = xmlTextReaderConstValue(reader);
printf("%d %d %s %d %d",
xmlTextReaderDepth(reader),
xmlTextReaderNodeType(reader),
name,
xmlTextReaderIsEmptyElement(reader),
xmlTextReaderHasValue(reader));
if (value == NULL)
printf("\n");
else {
if (xmlStrlen(value) > 40)
printf(" %.40s...\n", value);
else
printf(" %s\n", value);
}
}
void XmlParser::streamFile(const char *filename) {
xmlTextReaderPtr reader;
int ret;
reader = xmlReaderForFile(filename, NULL, 0);
if (reader != NULL) {
ret = xmlTextReaderRead(reader);
while (ret == 1) {
//processNode(reader);
ret = xmlTextReaderRead(reader);
}
xmlFreeTextReader(reader);
if (ret != 0) {
fprintf(stderr, "%s : failed to parse\n", filename);
}
} else {
fprintf(stderr, "Unable to open %s\n", filename);
}
}
I get the following result when I click build:
build/Debug/MinGW-Windows/XmlParser.o: In function ZN9XmlParser11processNodeEP14_xmlTextReader':
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:26: undefined reference toxmlTextReaderConstName'
C:\Users...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:30: undefined reference to xmlTextReaderConstValue'
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:37: undefined reference toxmlTextReaderHasValue'
C:\Users...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:37: undefined reference to xmlTextReaderIsEmptyElement'
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:37: undefined reference toxmlTextReaderNodeType'
C:\Users...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:37: undefined reference to xmlTextReaderDepth'
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:41: undefined reference toxmlStrlen'
build/Debug/MinGW-Windows/XmlParser.o: In function ZN9XmlParser10streamFileEPKc':
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:51: undefined reference toxmlReaderForFile'
C:\Users...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:53: undefined reference to xmlTextReaderRead'
C:\Users\...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:56: undefined reference toxmlTextReaderRead'
C:\Users...\Documents\NetBeansProjects\XmlBallotParser/XmlParser.cpp:58: undefined reference to `xmlFreeTextReader'
Which suggests that I have some sort of an issue compiling the program using libXml2. I saw that someone right here had the same error, and that the answer to this problem is correctly setting up the argument for compiling the program, however, I cannot figure out how to do this in NetBeans/Windows. I think what I need is details on how to actually get the arguments right. Any help would be appreciated. Thank you.
Add -lxml2 (gcc) or libxml2.lib (visual studio) to your linker.
This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
C code compiles as C++, but not as C
Edit:
I recompiled the source for the library as C, and that fixed it.
I've got this code I need to use in my application. It's for writing to the serial port, and I can't figure out how to get it to run in C. I've got a version in C++, as well as a version that looks more like C, designed to compile with the Borland C++ 5.5 compiler, but I can't get it to compile there or in my project.
Edit: I should note that it compiles (and links) when I compile as c++, but not when I compile as c.
Here's the linker error I get:
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's the c++ code. I don't need the command line functionality, I just need to be able to call Out32(). I don't even need to be able 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's the other sample:
#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.
You might need to wrap the prototypes of Inp32/Outp32 with "extern C { /* ... */ }".
This code looks like it's reading/writing the printer port, not the serial port. It's doing that by loading some DLL that gives direct access to the hardware. To get it to work, you'll need to use the same (or similar) DLL. From the looks of things, it's using Inpout32.dll, so getting that might be helpful.
I had to recompile the library as C, then use that version. The existing version was compiled as C++.