Trying to use CreateSolidBrush to change a window background color.
I've included wingdi.h, I believe I've linked gdi32.lib ( however I converted gdi32.lib to a gdi32.a by using LIB2A, and I wonder if this may be an issue? ).
I wouldn't mind using another function but I worry this could be come a re-occuring issue if I'm not able to find a solution.
Some relevant code:
#include <stdio.h>
#include <windows.h>
#include <wingdi.h>
#include <main.h>
DWORD CreateMainWindow(void)
{
.............
WNDCLASSEXA WindowClass = { 0 };
WindowClass.hbrBackground = CreateSolidBrush(RGB(200, 200, 200));
.............
}
I use a function to easily compile
int Compile()
{
................
int result = 0;
char *include = "C:\\Users\\Coding\\C\\src\\include";
char *link = "C:\\Users\\Coding\\C\\src\\lib";
char command[256];
if(snprintf(
command,
sizeof(command),
"gcc -o main -I%s -l gdi32 -L%s main.c", include, link) >= sizeof(command))
{
//exception catching and handling
}
else
{
system(command);
}
return result;
}
I have no reason to believe the file isn't being linked as I'm not receiving an error.
Also I'm only using Notepad++, mingw64, and command prompt.
The error is a linker error, because it can't find the shared library symbol CreateSolidBrush.
All that is needed is linker flag -lgdi32, so it links with MinGW's libgdi32.a.
Don't try to generate this file by converting it from some other file you found which is probably built with a totally different compiler. If you already experimented with that make sure to clean up any lingering gdi32 .a or .lib files from your previous attempts.
Well the answer was extremely simple, linkages and includes must come after the file.
C:\User> gcc main.c -lgdi32 -I<include path> -o main
If this was obvious then I apologize, hopefully this helps another confused individual
Related
I have 2 c files (& their header files). I have included the function "put" in the corresponding header, but I still have the following errors, when I input "gcc -o main main.c" in the terminal.
main.c:(.text+0x389): undefined reference to `put' collect2: error: ld
returned 1 exit status
may I know the reason? How should I modify my code?
I tried to change the linking order in makefile but failed. Any advice is appreciated, thanks!
CMakeLists.txt
cmake_minimum_required(VERSION 3.19)
project(Demo)
set(CMAKE_CXX_STANDARD 14)
include_directories(.)
add_executable(Demo
main.c main.h KeyValueStore.c KeyValueStore.h )
main.c
#include "main.h"
...
int main() {
...
if (strcmp("PUT", tokens[0]) == 0) {
put(tokens[1], tokens[2]);
...
}
main.h
...
#include "KeyValueStore.h"
...
KeyValueStore.c
#include "KeyValueStore.h"
#define BUFSIZE 1024
typedef struct KeyValueStore {
char key[BUFSIZE];
char value[BUFSIZE];
} KV_Store;
KV_Store kvStore[BUFSIZE];
...
int put(char* key, char* value){
...
}
KeyValueStore.h
...
typedef struct KeyValueStore;
int put(char* key, char* value);
...
Check to see if you have any .o files in that folder and delete them if you do. It's possible the compiler failed at some point while compiling which left *.o files that aren't linked properly
EDIT: I misread the question because for some reason it came up as a c++17 question for me. I'm not sure if what I said still applies to C though I do know it works with C++. Sorry about that to everyone that read my answer before I edited it
Not 100% sure if this is why you are having the error, though you need to put all .c files in the compiler.
So you currently are trying to "gcc -o main main.c" where instead you want to do something more like "gcc -o main main.c keyValueStore.c".
If you do not give the compiler every .c file, it won't have all the definitions and you will get an error similar to what you have.
I also don't really think you need main.h, assuming there isn't any more code in there, it really isn't worth having a whole extra file and instead just putting the #include in main.c.
I'm trying to get the ADC running on beaglebone black. The OS is Debian GNU/Linux 7.7. I'm using C language. When I try to compile the following code:
#include <stdio.h>
#include <unistd.h>
#include "pruio_c_wrapper.h"
#include "pruio_pins.h"
int main(int argc, const char *argv[]) {
PruIo *io = pruio_new(0, 0x98, 0, 1);
if (io->Errr) {
printf("Initialisation failed (%s)\n", io->Errr);
return 1;
}
if(pruio_config(io, 0, 0x1FE, 0, 4, 0)){
printf("Config failed (%s)\n", io->Errr);
return 1;
}
int a = 0;
int i;
while(1){
printf("\r%12o %12o %12o %12o %4X %4X %4X %4X %4X %4X %4X %4X\n", io->Gpio[0].Stat, io->Gpio[1].Stat, io->Gpio[2].Stat, io->Gpio[3].Stat, io->Value[1], io->Value[2], io->Value[3], io->Value[4], io->Value[5], io->Value[6], io->Value[7], io->Value[8]);
fflush(STDIN_FILENO);
usleep(1000);
}
pruio_destroy(io);
return 0;
}
But I get the following error:
undefined reference to 'pruio_new'
undefined reference to 'pruio_config'
I installed everything like FreeBasic compiler and pruss driver kit for freebasic and BBB and libpruio. I also copied all the header files in the same directory as the .c file, including "pruio_c_wrapper.h", "pruio-pins.h", "pruio.h" and all the other files in the src directory of libpruio. But it doesn't work.
Could you please tell me what to do?
Thanks
libfb is the FreeBASIC run-time library. When you want to compile against the old libpruio-0.0.x versions, you'll need an old FreeBASIC installation from
www{dot}freebasic-portal.de/dlfiles/452/bbb_fbc-0.0.2.tar.xz
Which installs /usr/local/lib/freebasic/libfb.so.
See the libpruio-0.0.x C example codes for compiler command line arguments (ie. header section of io_input.c).
But I recommend to use the new version libpruio-0.2 from (the last post links to the documentation of this new version)
http://www.freebasic-portal.de/dlfiles/592/libpruio-0.2.tar.bz2
which doesn't have this pitfalls, gcc compiles without FB installation, and provides new features like pinmuxing, PWM, CAP. There're small bugs in this versions C header, which is now named pruio.h: a missing enum and a copy / paste bug regarding a function name. See this thread for details:
http://www.freebasic.net/forum/viewtopic.php?f=14&t=22501
BR
Ok, I downloaded it, the binaries are in libpruio-0.0.2/libpruio/src/c_wrapper and so are the include files, copy the headers and libpruio.so to the same directory where the test.c file resides, and then
For the includes, you need to to append libpruio's include directory to the compiler command using -I. then you can do
#include <pruio_c_wrapper.h>
#include <pruio_pins.h>
You need to append the library to the linker command, with
-L. -lpruio
your complete compilation command will be then
gcc -o test -I. -L. -lpruio test.c
Im working on a project for stm32f4 to my school. Im using CooCox IDE.
I wanted to add new files "przerwania.c" and "przerwania.h" to write some functions there - not in "main.c". But I have no idea why CooCox is showing me errors.
Earlier I wanted to move some of functions from main.c to pwm.c and them work! But I would like to make a new files couse i have more functions.
Errors in CooCox look like this:
[mkdir] Created dir: D:\CooCox\CoIDE\workspace\testowy2\testowy2\Debug\obj
[cc] 12 total files to be compiled.
[cc] arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -Wall -ffunction-sections -g -O0 -c -DSTM32F407VG -DSTM32F4XX -DUSE_STDPERIPH_DRIVER -D__ASSEMBLY__ -ID:\CooCox\CoIDE\workspace\testowy2 -ID:\CooCox\CoIDE\workspace\testowy2\cmsis_boot -ID:\CooCox\CoIDE -ID:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\include -ID:\CooCox\CoIDE\workspace\testowy2\cmsis -ID:\CooCox\CoIDE\workspace\testowy2\cmsis_lib -ID:\CooCox\CoIDE\workspace D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_syscfg.c D:\CooCox\CoIDE\workspace\testowy2\pwm.c D:\CooCox\CoIDE\workspace\testowy2\dupa.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_boot\startup\startup_stm32f4xx.c D:\CooCox\CoIDE\workspace\testowy2\main.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_rcc.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_adc.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_gpio.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_boot\system_stm32f4xx.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_exti.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\misc.c D:\CooCox\CoIDE\workspace\testowy2\cmsis_lib\source\stm32f4xx_tim.c
[cc] Starting link
[cc] arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -g -nostartfiles -Wl,-Map=testowy2.map -O0 -Wl,--gc-sections -LD:\CooCox\CoIDE\configuration\ProgramData\testowy2 -Wl,-TD:\CooCox\CoIDE\configuration\ProgramData\testowy2/arm-gcc-link.ld -g -o testowy2.elf ..\obj\stm32f4xx_syscfg.o ..\obj\pwm.o ..\obj\dupa.o ..\obj\startup_stm32f4xx.o ..\obj\main.o ..\obj\stm32f4xx_rcc.o ..\obj\stm32f4xx_adc.o ..\obj\stm32f4xx_gpio.o ..\obj\system_stm32f4xx.o ..\obj\stm32f4xx_exti.o ..\obj\misc.o ..\obj\stm32f4xx_tim.o
[cc] ..\obj\main.o: In function `main':
[cc] D:\CooCox\CoIDE\workspace\testowy2/main.c:336: undefined reference to `Nowafunkcja'
[cc] collect2.exe: error: ld returned 1 exit status
main.c is quite long becouse i have some definitions of few long functions there, so I paste here only a part
#include "stm32f4xx.h"
#include "misc.h"
#include "stm32f4xx_syscfg.h"
#include "stm32f4xx_adc.h"
#include "stm32f4xx_exti.h"
#include "przerwania.h"//here is the problem
#include "pwm.h"
int main(void)
{
SystemInit();
//IniDiody();
//TimConfig();
//NVIC_Config();
//IniDiodyPWM();
LEDInit();
EXTILine0_Config();
PWM2();//wiwo
GPIO();//wiwo
Nowafunkcja();//PROBLEM
RCC_Konfiguracja_Adc12();
GPIO_Configuration_Adc1();
ADC1_Configuration();
GPIO_Configuration_Adc1();
GPIO_Configuration_Adc2();
ADC2_Configuration();
IniDiody(GPIO_Pin_14);
IniTimerPrzerwanie1();
while(1)
{
ADC_SoftwareStartConv(ADC1);
ADC_SoftwareStartConv(ADC2);
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET);
wynikADC1 = (float)ADC_GetConversionValue(ADC1);
while(ADC_GetFlagStatus(ADC2, ADC_FLAG_EOC) == RESET);
wynikADC2 = (float)ADC_GetConversionValue(ADC2);
wartosc = (int)(wynikADC2 * 15);
//doPWM=(((float)ADCResult) / 41);
//wartosc = (int) doPWM;
//TIM2->CCR3 = (int) doPWM;
TIM3->CCR2 = 65535;
TIM3->CCR1 = wartosc;//(int)(wynikADC2 * 15);
wartoscPrescalera=(int)SystemCoreClock;
}
}
and files:
przerwania.h
#ifndef __przerwaniah
#define __przerwaniah
void Nowafunkcja(void);
#endif
przerwania.c
#include "przerwania.h"
void Nowafunkcja(void)
{
//nothing here - just for test
}
Do you have any idea what is the problem? I'm thinking about this since yesterday and its wird :/
I'll appreciate your help!
Take a look at the line under [cc] 12 total files to be compiled.
When you added pwm.c, you also informed the compiler to include this file. You'll see it listed there. przerwania.c is not.
If you add przerwania the same way you added pwm, your IDE will take care of making sure it is included in the build.
I'm not sure what your current file/folder structure looks like:
http://www.coocox.org/CoIDE/Project_management_config.html can help you determine how to pull those new files into the build.
FWIW:
The (anthropomorphized) compiler step says: Is this valid code? So it looks though your main.c, sees that you included przerwania.h, and comes to the conclusion that you correctly used the Nowafunkcja function (just matched the signature). Even though at this point, it has NOT looked into przerwania.c to find out what it does. The compiler goes on to do this for all of your files and keeps track of what functions are defined in each file. Note that it never found the definition Nowafunkcja, because the compiler never compiled przerwania.c. It did however find the declaration in the .h (because main.c told it exactly where to find the .h)
The linker then gets this stuff from the compiler, including what functions have been defined in all your .c files. That's the first point where something tries to answer the question "Now what code do I actually need to run when he asked me to Nowafunkcja()?". So that's the first point in the build when the tools realized, I never found code for Nowafunkcja in any of the .c files I was looking in.
So, I think that roughly answers "Why", but we need to know more about your project organization to give you a "fix" to make it work.
I’m trying to create ./configure + make set for building C codes in following structure by using autotools. drive.c uses function in mylib.c
[mylib]
+mylib.c
+mylib.h
[src]
+drive.c
More details are here.
[mylib.c]
#include <stdio.h>
#include "mylib.h"
int main(){
mylib();
return 0;
}
void
mylib(void)
{
printf ("Hello world! I AM mylib \n");
}
[mylib.h]
void mylib(void);
[drive.c]
#include <mylib.h>
int
main (int argc, char **argv)
{
mylib();
return 0;
}
Actually I’ve given main() both mylib.c and drive.c.
If I make them on CentOS process is noremally finished however If I make them on MINGW an error message multiple definition ofmain'` is shown
How can I make them on MINGW even if they have multiply have main()?
And those followings are config files for autotools.
[confiugre.ac]
AC_PREREQ([2.69])
AC_INIT([libmylib], [1], [admin#localhost])
AC_CONFIG_SRCDIR([mylib/mylib.c])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_MACRO_DIR([m4])
AM_INIT_AUTOMAKE([foreign])
LT_INIT
AC_PROG_CC
AC_CONFIG_FILES([mylib/Makefile
src/Makefile
Makefile])
AC_OUTPUT
[Makefile.am]
SUBDIRS = mylib src
ACLOCAL_AMFLAGS = -I m4
[Makefile.am#src]
bin_PROGRAMS = drive
drive_SOURCES = drive.c
LDADD = ../mylib/libmylib.la
AM_CPPFLAGS = -I../mylib
[Makefile.am#mylib]
lib_LTLIBRARIES = libmylib.la
libmylib_la_SOURCES = mylib.c
include_HEADERS = mylib.h
You are confusing things, the idea of having multiple main() is fundamentally wrong. Libraries never ever contain a main() function.
(With the exception of Windows DLLs that contain a DllMain, but that means something different.)
If you want to provide a test case for your library, you make the test case as a separate project which includes the library. The test code should not be inside the library itself, neither should main().
Also, I very much doubt you are able to build a program with several function definitions that have the same name, be it main() or something else. If you believe you have managed this, I would either suspect that you haven't linked the files correctly, or that the linker is crap.
I need to create an application to extract one file from zip archive, after which I want to compile it for Android.
I'm using Ubuntu, with libzip-0.10.1 pre-installed.
I created C project in Eclipse, added include path and found simple script for extracting file. Unfortunately I cannot get the following to build and I could use some advice.
// zip.c file
#include <stdio.h>
#include <stdlib.h>
#include <zip.h>
int main(int argc, char **argv) {
struct zip *zip_file;
struct zip_file *file_in_zip;
int err;
int files_total;
int file_number;
int r;
char buffer[10000];
if (argc < 3) {
fprintf(stderr,"usage: %s <zipfile> <fileindex>\n",argv[0]);
return -1;
};
zip_file = zip_open(argv[1], 0, &err);
if (!zip_file) {
fprintf(stderr,"Error: can't open file %s\n",argv[1]);
return -1;
};
file_number = atoi(argv[2]);
files_total = zip_get_num_files(zip_file);
if (file_number > files_total) {
printf("Error: we have only %d files in ZIP\n",files_total);
return -1;
};
file_in_zip = zip_fopen_index(zip_file, file_number, 0);
if (file_in_zip) {
while ( (r = zip_fread(file_in_zip, buffer, sizeof(buffer))) > 0) {
printf("%s",buffer);
};
zip_fclose(file_in_zip);
} else {
fprintf(stderr,"Error: can't open file %d in zip\n",file_number);
};
zip_close(zip_file);
return 0;
};
Also I added few .h files to include directory in my project and few .c files to directory with zip.c file. After that all dependences was good, but I have an error:
‘struct zip’ has no member named ‘default_password’ in file zip_fopen_index.c
The file zip_fopen_index.c is:
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "zipint.h"
ZIP_EXTERN struct zip_file *
zip_fopen_index(struct zip *za, zip_uint64_t fileno, int flags)
{
return zip_fopen_index_encrypted(za, fileno, flags, za->default_password); // error here
}
First of all allow me some comments:
Your program is not compiled and linked by Eclipse.
Compiling is done by the compiler (gcc using option -c):
make all
Building file: ../zip.c
Invoking: GCC C Compiler
gcc -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"zip.d" -MT"zip.d" -o "zip.o" "../zip.c"
Finished building: ../zip.c
Linking is done by the linker (via the compiler using option -o):
Invoking: GCC C Linker
gcc -o "unzipper" ./zip.o
./main.o: In function `zip':
/home/alk/workspace/unzipper/Debug/../zip.c:20: undefined reference to `zip_open'
/home/alk/workspace/unzipper/Debug/../zip.c:27: undefined reference to `zip_get_num_files'
/home/alk/workspace/unzipper/Debug/../zip.c:33: undefined reference to `zip_fopen_index'
/home/alk/workspace/unzipper/Debug/../zip.c:35: undefined reference to `zip_fread'
/home/alk/workspace/unzipper/Debug/../zip.c:38: undefined reference to `zip_fclose'
/home/alk/workspace/unzipper/Debug/../zip.c:43: undefined reference to `zip_close'
collect2: ld returned 1 exit status
Eclipse provides a framework helping you in managing all sources and their references as also spawing compiler and linker tasks and setting their options.
When the linker told you there where undefined references to the zip_*function during the build of your program, the cause for this was, you were missing to tell the linker (via the compiler, via Eclipse) where those zip_* functions could be found.
Those zip_* functions are located in a library, namely libzip.
So what you as the programmer need to tell the linker (via the compiler, via Eclipse) is to link those functions against what the compiler compiled from your sources.
As the result the linker is able to create a runnable program from your compiled sources together with all libraries needed. Certain libraries are know to Eclipse (and therfore to the linker) by default, for example the one containing the C standard functions, namely libc.
To get things going:
1 Remove the source files you pulled from the libzip librarie's sources from your project. Those sources had been compiled into the library libzip, which you will use in your project.
2 Tell the linker (via Eclipse) to use libzip for your project.
Do so by following the steps below:
open the project's properties
click 'C/C++ General'
click 'Path and Symbols', on the left select the 'Libraries' tab, there click 'Add' and enter zip
finally click 'OK'
3 Then try to build your program:
Building target: unzipper
Invoking: GCC C Linker
gcc -o "unzipper" ./zip.o -lzip
Finished building target: unzipper
(Please note additional option -lzip!)
If the developement version of 'libzip' had been installed properly before, you should be fine.
PS: unzipper was the name I used for the Eclispe project to produce the examples.
PSS: I used Eclipse Juno SR1