I want to wirte a function with variable arguments in this way:
static void configElement(U32 localFaultId,
char* name,
U32 report,
U32 localId,
U32 detectTime,
U32 ceaseTime,...)
{
U32 i = 0;
U32 tmpNo = 0;
va_list ap;
if (nofFaults >= MAX_NOF_LOCAL_FAULTS)
{
//something here
return;
}
else
{
faultList[nofFaults].ceaseTime = ceaseTime;
va_start(ap, ceaseTime);
tmpNo = va_arg(ap, U32);
while ((tmpNo!= END_MARK) && (i < MAX_NOF_DEPEND))
{
faultList[nofFaults].dependList[i++].faultNo = tmpNo;
}
faultList[nofFaults].dependList[i].faultNo = END_MARK;
/* Finish by increment nofFaults parameter */
va_end(ap);
nofFaults++;
}
}
However, I got the error msg when compiling this code:
fault_manager.cc:3344: error: expected primary-expression before ',' token
fault_manager.cc:3387: error: expected primary-expression before 'U32'
fault_manager.cc:3387: error: expected `)' before 'U32'
fault_manager.cc:3387: error: expected `)' before ';' token
fault_manager.cc:3387: error: expected `)' before ';' token
I have no idea what is going wrong here. My platform is Windows, and I'm using cygwin+Eclipse(CDT). The version of gcc is 4.1.1.
Any idea will be appreciated much!
It looks like the compiler does not know what U32 is. Did you include all necessary headers?
Related
I have c++ file like below one,
#include <iostream>
using namespace std;
extern "C" {
#include "sample_publish.c"
}
int main()
{
int antenna_id = 123;
send_message_to_mqtt(&antenna_id);
}
I have included a c file in c++ file and I need to pass the variable antenna_id to the function send_message_to_mqtt and the same is in c file like below one.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTClient.h"
void send_message_to_mqtt(int *antenna_id) {
MQTTClient client;
MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
MQTTClient_message pubmsg = MQTTClient_message_initializer;
MQTTClient_deliveryToken token;
int rc;
MQTTClient_create(&client, "tcp://mqtt1.mindlogic.com:1883", "ExampleClientPub",
MQTTCLIENT_PERSISTENCE_NONE, NULL);
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to connect, return code %d\n", rc);
exit(EXIT_FAILURE);
}
printf("DATA FROM C++:::%d\n", *antenna_id);
char payload_data[] = "hi";
//pubmsg.payload = payload_data;
pubmsg.payload = *antenna_id
pubmsg.payloadlen = (int)strlen(*antenna_id);
pubmsg.qos = 1;
pubmsg.retained = 0;
MQTTClient_publishMessage(client, "MQTT-Examples", &pubmsg, &token);
printf("Waiting for up to %d seconds for publication of %s\n""on topic %s for client with ClientID: %s\n",(int)(10000L/1000), "Hello World!", "MQTT-Examples", "ExampleClientPub");
rc = MQTTClient_waitForCompletion(client, token, 10000L);
printf("Message with delivery token %d delivered\n", token);
MQTTClient_disconnect(client, 10000);
MQTTClient_destroy(&client);
// return rc;
}
When I execute a c++ file, the antenna_id variable is doesnt accessible in c file which in turn not allowing me to map against pubmsg.payload and this is due to the below error,
dell#dell-Inspiron-5379:~/workspace_folder$ g++ sample.cpp -o sample -lpaho-mqtt3c
In file included from sample.cpp:5:0:
sample_publish.c: In function ‘void send_message_to_mqtt(int*)’:
sample_publish.c:30:22: error: invalid conversion from ‘int’ to ‘void*’ [-fpermissive]
pubmsg.payload = *antenna_id
^~~~~~~~~~~
sample_publish.c:31:5: error: expected ‘;’ before ‘pubmsg’
pubmsg.payloadlen = (int)strlen(*antenna_id);
^~~~~~
How to overcome this one?
A guess on the problem, it's most likely this line:
pubmsg.payload = *antenna_id
Besides missing the semicolon, the payload is a pointer to the first byte of the data to be sent. That is, you should not dereference the pointer:
pubmsg.payload = antenna_id;
On a related note, this line is also very wrong:
pubmsg.payloadlen = (int)strlen(*antenna_id);
The strlen function is to get the length if a null-terminate byte string.
The length of an int can be gotten with the sizeof operator:
pubmsg.payloadlen = sizeof *antenna_id;
Note that here you must use the dereference operator, otherwise you get the size of the pointer itself.
Trying to perform SPI communication on ARM processor running on Linux Debian.
Unable to compile the code below (error: expected primary-expression before '.' token)
g++ comm.cpp -o comm
I am not sure how I can compile this code Is there something I am missing ? Thank you.
struct spi_ioc_transfer tr = {
.tx_buf = (unsigned long)tx,
.rx_buf = (unsigned long)rx,
.len = ARRAY_SIZE(tx),
.delay_usecs = delay,
.speed_hz = speed,
.bits_per_word = bits
};
I'm struggling to finish this code.
#include (sorry but it won't show up the #include such as stdio.h AND OTHERS) But this is not the problem.
using namespace std;
struct CustomerFile {
int arrivalTime;
string driverfName,
driverlName,
typeOfDriver,
driverLicNumber,
vehicleMake,
vehicleModel,
Lot_taken,
vehicleRegNumber,
attendantName,
ParkingArea,
Comments,
checkOutDateTime,
checkInDateTime;
};
int arrivalTime;
string driverfName,
driverlName,
typeOfDriver,
driverLicNumber,
vehicleMake,
vehicleModel,
Lot_taken,
vehicleRegNumber,
attendantName,
ParkingArea,
Comments,
checkOutDateTime,
checkInDateTime;
int main(int argc, char * * argv) {
FILE * cfPtr;
if ((cfPtr = fopen("CustomerFile.dat", "rb+")) == NULL) {
printf("file could not be opened");
} else {
printf("\nFile is Written to");
printf("\nFile is open");
printf("\n\n\nEnter Vehicle Registration Number: ");
scanf("%s", & CustomerFile.vehicleRegNumber);
while (CustomerFile.vehicleRegNumber != 0) /*#IF THE USER does not enter 0 the loops should begin, but there is a problem here*/
{
printf("\nFirst Name: ");
fscanf("%s", CustomerFile.driverfName); /*here is the problem, I think is had something to do with the struct name*/
printf("\nLast Name: ");
printf("\nType of Driver: ");
printf("\nDriver's License Number: ");
printf("\nVehicle Make: ");
printf("\nVehicle Model: ");
printf("\nComments ");
printf("\nParking SpaceTaken ");
printf("\n\nenter firstname, lastname");
fscanf(stdin, "%s%s%s%s%s%s%s%s1f", CustomerFile.driverfName I think this has something to do with the statement * /
CustomerFile.driverlName / * okay here * /
CustomerFile.typeOfDriver / * okay here * /
CustomerFile.driverLicNumber / * okay here * /
CustomerFile.vehicleMake / * okay here * /
CustomerFile.vehicleModel / * okay here * /
CustomerFile.Comments / * okay here * /
&CustomerFile.Lot_taken); / * okay here * /
fwrite( sizeof(struct CustomerFile ), 1, cfPtr);
}
fclose( cfPtr);
}
return 0;
}
Okay the problem is that it keeps giving the errors;*
File.cpp:144: error: expected primary-expression before ‘.’ token
File.cpp:148: error: expected primary-expression before ‘.’ token
File.cpp:162: error: expected primary-expression before ‘.’ token
File.cpp:172: error: invalid conversion from ‘unsigned int’ to ‘const void*’
File.cpp:172: error: invalid conversion from ‘FILE*’ to ‘size_t’
/usr/include/stdio.h:708: error: too few arguments to function ‘size_t fwrite(const void*, size_t, size_t, FILE*)’
File.cpp:172: error: at this point in file
I believed or read that it has something with the fact that a C++ complier does not work with c99. If so, then how do you use structs in c++? I know you use a struct by just for example CustomerFile.driverlName, however, the complier keep refusing it. Also I'm having problems with the while loop. I'm familiar with c and c++ we were taught both c and c++, the code is to be written in c++ but the text book gives c code that won't run in a c++ complier.
CustomerFile is a class, so it won't work when you try to access data members off of it as if it were an instance. To create an instance, do:
CustomerFile file;
And replace all instances of Customer. with file. and it should resolve the error.
You defined a datatype CustomerFile. For using defined structure CustomerFile you have create an object and use it. For eg :
CustomerFile customer;
customer.vehicleModel = "ABC";
vehicleRegNumber is of type string not integer compare it with 0 like this
while (customer.vehicleRegNumber != "0" )
Add , between variable names
fscanf( stdin, "%s%s%s%s%s%s%s%s1f", customer.driverfName, customer.driverlName ,
The fscanf() function is a C function, it does not know about std::string (or classes). So you have use a temp c string like this
char temp[100];
printf("\nFirst Name: ");
fscanf(stdin, "%99s", temp );
customer.driverfName = temp;
I have this code:
FILE *f = fopen(intPath, "r");
Node *n;
if (f) {
try {
n = parse(f, intPath);
} catch (SyntaxError e) {
fclose(f); /***** line 536 *****/
throw LangException(
builtin_classes::exception_class::create_ImportError(
String::fromAscii(e.filename)->
append(String::fromAscii(":"))->
append(String::fromInt(e.line))->
append(String::fromAscii(":"))->
append(String::fromInt(e.col))->
append(String::fromAscii(": syntax error: "))->
append(String::fromAscii(e.message))
);
}
fclose(f);
return n->eval(scope);
} else {
throw LangException(
builtin_classes::exception_class::create_ImportError(
String::fromAscii("failed to open file for reading")
),
line,
col
);
}
And the compiler gives this error:
nodes.cpp:537:40: error: expected primary-expression before ‘(’ token
nodes.cpp:544:94: error: expected ‘)’ before ‘;’ token
I have no clue what it could be, especially since that code sample has another statement which does the same thing, and it doesn't cause an error.
throw LangException(
builtin_classes::exception_class::create_ImportError(
String::fromAscii(e.filename)->
append(String::fromAscii(":"))->
append(String::fromInt(e.line))->
append(String::fromAscii(":"))->
append(String::fromInt(e.col))->
append(String::fromAscii(": syntax error: "))->
append(String::fromAscii(e.message))
) // This closes the function call
; // You didn't close the throw here!
Your ( and your ) don't match in that large, first throw LangException block.
The compiler tells you what is wrong. The throw LangException( doesn't have a ).
Exactly what it says. You are missing a ‘)’ before ‘;’ token on that line.
LangException(...
is not closed.
I get the following errors when trying to compile the below code using g++. When I compile it using gcc it works fine (other than a few warnings). Any help appreciated.
g++ ush7.cpp
ush7.cpp: In function ‘int signalsetup(sigaction*, sigset_t*, void (*)(int))’:
ush7.cpp:93: error: expected unqualified-id before ‘catch’
ush7.cpp:95: error: expected primary-expression before ‘catch’
ush7.cpp:95: error: expected `;' before ‘catch’
ush7.cpp:97: error: expected primary-expression before ‘catch’
ush7.cpp:97: error: expected `;' before ‘catch’
ush7.cpp:100: error: expected primary-expression before ‘catch’
ush7.cpp:100: error: expected `)' before ‘catch’
ush7.cpp:108: error: expected `)' before ‘;’ token
ush7.cpp:108: error: expected `)' before ‘;’ token
ush7.cpp: In function ‘int makeargv(const char*, const char*, char***)’:
ush7.cpp:137: error: invalid conversion from ‘void*’ to ‘char*’
ush7.cpp:145: error: invalid conversion from ‘void*’ to ‘char**’
int signalsetup(struct sigaction *def, sigset_t *mask, void (*handler)(int))
{
struct sigaction catch;
catch.sa_handler = handler; /* Set up signal structures */
def->sa_handler = SIG_DFL;
catch.sa_flags = 0;
def->sa_flags = 0;
if ((sigemptyset(&(def->sa_mask)) == -1) ||
(sigemptyset(&(catch.sa_mask)) == -1) ||
(sigaddset(&(catch.sa_mask), SIGINT) == -1) ||
(sigaddset(&(catch.sa_mask), SIGQUIT) == -1) ||
(sigaction(SIGINT, &catch, NULL) == -1) ||
(sigaction(SIGQUIT, &catch, NULL) == -1) ||
(sigemptyset(mask) == -1) ||
(sigaddset(mask, SIGINT) == -1) ||
(sigaddset(mask, SIGQUIT) == -1))
return -1;
return 0;
}
catch is a keyword in C++ but not in C.
Please see my related answer C is not a proper subset of C++ here, or even better here.
You should be able to use a #define if you don't want to change the rest of the code.
#define catch _catch