I try to built modular programming Makefile for compiling a module named hello-1.c.
I researched create make file and built video but i couldn't success.
My code :
#include <linux/module.h>
#include <linux/kernel.h>
int init_module(void)
{
printk(KERN_INFO "Hello world \n");
return 0;
}
void cleanup_module(void)
{
printk(KERN_INFO "Goodbye world \n");
}
if you look up youtube modular programming , it tell you how to compile. To learn more on how to compile modules which are not part of the official kernel see file linux/Documentation/kbuild/modules.txt.
Makefile for compiling a module named your-file-name--1.c:
obj-m += your-file-name-1.o
all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
Related
I am using Nvim to try and develop a Mac application. I have just imported AppKit.h to instantiate a sharedApplication.
I am using coc-clangd for autocompletion. I am getting the following error when I import AppKit.h.
In included file: function does not return NSString
[clang: format_attribute_result_not]
The code:
#include <stdio.h>
#include <AppKit/AppKit.h>
int main(int argc, const char * argv[])
{
printf("Hello world");
return 0;
}
I should also mention that the code is compiling just fine. I have tried the following compile commands and both of them have worked.
clang -framework AppKit -o a osx_main.mm
clang -Wall -o a osx_main.mm
You should choose command line tool version,
Xcode ▶ Preferences ▶ Location ▶ Command Line Tool ▶
then choose appropriate command line tool version.
I have some undefined reference errors in an Apache module. I've cut the source code down to a minimum that reproduced the error. Below is the source for "mod_test.c" ...
#include "httpd.h"
#include "http_config.h"
#include "http_request.h"
#include "http_protocol.h"
#include "http_core.h"
#include "http_main.h"
#include "http_log.h"
#include "ap_mpm.h"
#include "apr_strings.h"
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <netdb.h>
module AP_MODULE_DECLARE_DATA test_module;
static int test_handler(request_rec *r);
static int test_init(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s);
/* Structure containing state information for the module */
typedef struct {
} ns_mod_config;
static int ns_typematch(request_rec *r) {
ns_mod_config *ns_scfg = ap_get_module_config(r->server->module_config,
&test_module);
core_request_config *creq_cfg;
creq_cfg = ap_get_core_module_config(r->request_config);
return 0;
}
module AP_MODULE_DECLARE_DATA test_module = {
STANDARD20_MODULE_STUFF,NULL,NULL,NULL,NULL,NULL,NULL};
I am using a more-or-less standard Makefile for compiling the module (note that the install option has been removed as this is a test to demonstrate the problem.)
APXS=/usr/local/apache2/bin/apxs
APXS_OPTS=-Wc, -Wc,-DDST_CLASS=3
SRC=src/mod_test.c
OBJ=src/.libs/mod_test.so
$(OBJ): $(SRC)
#echo
$(APXS) $(APXS_OPTS) -c $(SRC)
#echo
#echo write '"make install"' to install module
#echo
clean:
rm -f src/.libs/*
rm -f src/*.o
rm -f src/*.lo
rm -f src/*.la
rm -f src/*.slo
rmdir src/.libs
The compile fails as follows:
/usr/local/apache2/bin/apxs -Wc, -Wc,-DDST_CLASS=3 -c src/mod_test.c
/usr/local/apache2/build/libtool --silent --mode=compile gcc -prefer-pic -DLINUX -D_REENTRANT -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -g -O2 -pthread -I/usr/local/apache2/include -I/usr/local/apache2/include -I/usr/local/apache2/include -DDST_CLASS=3 -c -o src/mod_test.lo src/mod_test.c && touch src/mod_test.slo
src/mod_test.c: In function âns_typematchâ:
src/mod_test.c:34:3: error: unknown type name âcore_request_configâ
core_request_config *creq_cfg;
^~~~~~~~~~~~~~~~~~~
src/mod_test.c:35:14: warning: implicit declaration of function âap_get_core_module_configâ [-Wimplicit-function-declaration]
creq_cfg = ap_get_core_module_config(r->request_config);
^~~~~~~~~~~~~~~~~~~~~~~~~
src/mod_test.c:35:12: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
creq_cfg = ap_get_core_module_config(r->request_config);
^
apxs:Error: Command failed with rc=65536
.
Makefile:23: recipe for target 'src/.libs/mod_test.so' failed
make: *** [src/.libs/mod_test.so] Error 1
I am not sure how this can occur. http_core.h is present in /usr/local/apache2/include and it does include the definitions that are claimed missing by the compile. Six other modules on the same system compile without errors, though none of them use this specific reference to the core data structures.
Help will be gratefully received.
After posting to the Apache modules mailing list, it develops that the problem is in two parts.
Defining CORE_PRIVATE is required under Apache 2.2 to have access to the core data structures.
ap_get_core_module_config is an Apache 2.4 construct.
I'm trying to build a simple hello world in SystemC with CMake.
Here's the SystemC file main.cpp:
#include <systemc.h>
using namespace std;
SC_MODULE (hello_world) {
SC_CTOR (hello_world) {
}
void say_hello() {
cout << "Hello World SystemC" << endl;
}
};
int sc_main(int argc, char* argv[]) {
hello_world hello("HELLO");
hello.say_hello();
return(0);
}
Here is the CMakeLists.txt:
cmake_minimum_required(VERSION 3.1)
project(SystemCExample)
set (CMAKE_PREFIX_PATH /usr/local/systemc-2.3.2)
include_directories(${CMAKE_PREFIX_PATH}/include)
find_library(systemc systemc ${CMAKE_PREFIX_PATH}/lib-linux64)
link_directories(${CMAKE_PREFIX_PATH}/lib-linux64)
set(CMAKE_CXX_STANDARD 11) # C++11...
set(CMAKE_CXX_STANDARD_REQUIRED ON) #...is required...
set(CMAKE_CXX_EXTENSIONS OFF) #...without compiler extensions like gnu++11
aux_source_directory(. SRC_LIST)
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(SystemCExample systemc)
I keep getting the error:
/usr/local/systemc-2.3.2/include/sysc/kernel/sc_ver.h:179: error: undefined reference to `sc_core::sc_api_version_2_3_2_cxx201103L<&sc_core::SC_DISABLE_VIRTUAL_BIND_UNDEFINED_>::sc_api_version_2_3_2_cxx201103L(sc_core::sc_writer_policy)'
It points to sc_ver.h to the line:
api_version_check
(
SC_DEFAULT_WRITER_POLICY
);
The error mesage appears also when I replace the main.cpp with another simple example. How can I fix it?
Most likely you've built SystemC with C++98. It is default. Currently it requires that you use same C++ standard during library build and for your application.
Here are steps to build SystemC 2.3.2 with CMake
Download SystemC 2.3.2, unpack, change directory to systemc-2.3.2
cd /path/to/systemc-2.3.2
Create build directory:
mkdir build
Configure SystemC build with C++11 support. I also recommend to build it in Debug mode, this helps while learning. Later you can switch to Release builds to speed-up simulation
cmake ../ -DCMAKE_CXX_STANDARD=11 -DCMAKE_BUILD_TYPE=Debug
Build
cmake --build .
CMake will automatically export SystemC library targets to User Package Registry: https://cmake.org/cmake/help/v3.0/manual/cmake-packages.7.html#user-package-registry
Optionally you can install it somewhere, read CMake manual to learn how.
Now try to create sample SystemC project:
main.cpp
#include <systemc.h>
SC_MODULE (hello_world) {
SC_CTOR (hello_world)
{
SC_THREAD(say_hello);
}
void say_hello()
{
cout << "Hello World SystemC" << endl;
}
};
int sc_main(int argc, char* argv[])
{
hello_world hello("HELLO");
sc_start();
return (0);
}
CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(test_systemc)
find_package(SystemCLanguage CONFIG REQUIRED)
set (CMAKE_CXX_STANDARD ${SystemC_CXX_STANDARD})
add_executable(test_systemc main.cpp)
target_link_libraries(test_systemc SystemC::systemc)
Build, run, expected output:
./test_systemc
SystemC 2.3.2 --- Oct 14 2017 19:38:30
Copyright (c) 1996-2017 by all Contributors,
ALL RIGHTS RESERVED
Hello World SystemC
I'm trying to link with a simple C lib on windows against Rust library
My lib is .h
extern "C" {
void say_hello(const char* s);
}
.cpp
#include <stdio.h>
void say_hello(const char* s) {
printf("hello world");
}
My Rust file
#[link(name="CDbax", kind="static")]
extern "C" {
fn say_hello(s: *const libc::c_char) -> () ;
}
Linking fails by giving an error with one of the data symbols
error: linking with `gcc` failed: exit code: 1
note: "gcc" "-Wl,--enable-long-section-names" "-fno-use-linker-plugin" "-Wl,--nxcompat" "-Wl,--large-address-aware" "-shared-libgcc" "-L" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib" "e:\Rust\DBTools\DBAnalytics\target\debug\DBAnalytics.o" "-o" "e:\Rust\DBTools\DBAnalytics\target\debug\DBAnalytics.dll" "e:\Rust\DBTools\DBAnalytics\target\debug\DBAnalytics.metadata.o" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\libstd-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\libcollections-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\librustc_unicode-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\librand-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\liballoc-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\liblibc-11582ce5.rlib" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib\libcore-11582ce5.rlib" "-L" "e:\Rust\DBTools\DBAnalytics\target\debug" "-L" "e:\Rust\DBTools\DBAnalytics\target\debug\deps" "-L" "C:\Program Files (x86)\Rust 1.2\bin\rustlib\i686-pc-windows-gnu\lib" "-L" "e:\Rust\DBTools\DBAnalytics\.rust\bin\i686-pc-windows-gnu" "-L" "e:\Rust\DBTools\DBAnalytics\bin\i686-pc-windows-gnu" "-Wl,-Bstatic" "-Wl,--whole-archive" "-l" "CDbax" "-Wl,--no-whole-archive" "-Wl,-Bdynamic" "-l" "ws2_32" "-l" "userenv" "-l" "advapi32" "-shared" "-l" "compiler-rt"
note: Warning: corrupt .drectve at end of def file
Cannot export ??_C#_0M#LACCCNMM#hello?5world?$AA#: symbol not found
The library is build on MSVC2013 as a simple static lib. The string "hello world" is in the data section, so I wouldn't expect it to cause a link error. Are there some specific settings I need to be aware about when linking with C libraries on windows?
Btw it's 32bit MSVC lib.
Ok, a few things. First of all, there's no such thing as a "static DLL": a DLL is a dynamically linked library.
Secondly, Rust uses the MinGW toolchain and runtime. Mixing MSVC and MinGW runtimes can cause odd things to happen, so it's probably best avoided if at all possible. Rust has only recently landed very early support for building using the MSVC runtime.
However, you can get this specific example to work, apparently without any ill effects. You just need to change a few things:
You need to use a dynamic library; my understanding is that this makes bad interactions a little less likely.
You need to actually compile say_hello with C linkage, not C++ linkage. You did this in the header, but not in the source file.
You need to publicly export say_hello from the library.
Thus:
hello.rs:
#[link(name="hello", kind="dylib")]
extern {
fn say_hello();
}
fn main() {
unsafe { say_hello(); }
}
hello.h:
#ifndef HELLO_H
#define HELLO_H
extern "C" {
__declspec(dllexport) void say_hello();
}
#endif
hello.cpp:
#include <cstdio>
#include "hello.h"
void say_hello() {
printf("hello world\n");
}
build.cmd
cl /LD hello.cpp
rustc -L. hello.rs
On my machine, this produces hello.exe and hello.dll; when run, hello.exe prints out hello world.
I'm using cmake with custom GCC(with shared libraries) and during cmake compiler test I get following error:
The C compiler "/path/to/gcc/bin/gcc" is not able to compile a simple test program.
...
/path/to/gcc/x86_64-unknown-linux-gnu/bin/ld:
cannot find -lgcc_s
Here's a simple "testme.cpp" file:
#include <iostream>
int main( int argc, char * argv[] ) {
std::cout << "Hello world" << std::endl;
return 0;
}
and here's a CMakeLists.txt:
cmake_minimum_required(VERSION 2.6.2)
project(testme)
file( GLOB srcs "testme.cpp" )
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g -O0 -Wall -std=c++11")
set(CMAKE_LDFLAGS "${CMAKE_LDFLAGS} -L/path/to/gcc/lib/gcc/x86_64-unknown-linux-gnu/lib64")
add_executable(testme ${srcs})
to build with my custom GCC I'm exporting CXX and CC:
export CXX=/path/to/gcc/bin/g++
export CC=/path/to/gcc/bin/gcc
and then hit:
cmake .
make
and the result is that it can't find libgcc_s.so which is located in the "lib/gcc/x86_64-unknown-linux-gnu/lib64" folder.
However, when I invoke gcc like this:
/path/to/gcc/bin/g++ testme.cpp -L/path/to/gcc/lib/gcc/x86_64-unknown-linux-gnu/lib64
it compiles successfully. I've tried to add it to LD_LIBRARY_PATH but that doesn't seem to help.
So, is there a way to pass library path to CMake compiler check?
Chrono Kitsune was sort of right ... /path/to/gcc/x86_64-unknown-linux-gnu/bin/ld was build with "--enable-shared" and libraries where not in systems search path.