When you #include files with <>, the compiler searcher for the headers in a certain location(s). Where am I supposed to keep the lua files for that to work? I guess I know where all(?) of gcc's .h files are at. Or do I have to keep them in the same project folder and do #include "lua.h" instead? I assume I should use whatever is in LuaDist instead of the binaries, since it's not compiled.
(I'm using Windows if it's needed to know that)
Edit: This is probably useless for Windows, sorry. If anyone running Linux/BSD/macOS/Solaris/etc. comes across this in the future, though:
There should be a pkg-config file available for Lua which will tell you exactly what flags you need. For Lua 5.1 (the version I see on Fedora 28), it's lua-5.1. So, to compile:
cc … `pkg-config --cflags --libs lua-5.1`
Related
I want to use functions in the header files gmp.h and mpfr.h, which are in the file /opt/local/include.
But when I run gcc with -v, all of the search paths are something like /Application/Xcode.app/Contents/etc.
I have tried adding LD_LIBRARY_PATH="/opt/local/include" to .bash_profile but it doesn't work. The compiler either tells me that 'gmp.h' file not found, or Undefined symbols for architecture x86_64.
What should I do?
Converting comments into an answer.
You need to add -I/opt/local/include to compile commands (to specify where the headers are) and -L/opt/local/lib and -lgmp and -lmpfr (possibly in the reverse order — MPFR before GMP) to link commands.
That works! Would you mind explaining a little bit the logic behind this? For example if I had another header file header.h I need, how should I include it?
You include it with #include "header.h". You compile the code with -I/directory/containing/header to find the header. You specify where the library (libheader.a or libheader.dylib, since you seem to be on macOS) is too, with -L/directory/containing/lib and -lheader — or whatever is appropriate.
The -I tells the preprocessor to look in the named directory for header files, so it looks for /directory/containing/header/header.h, for example.
The -L tells the linker where to find libraries (so it looks for /directory/containing/lib/libheader.dylib etc).
The -lheader tells the linker to look for libheader.a or libheader.dylib (or local equivalents) for the libraries.
Except for the use of .dylib vs .so vs .dll vs … (and .a vs .lib vs …), the same principles apply to other systems too.
This is probably a duplicate.
I want to run serial commands from a Bealgebone to a 4Dsystems display. Therefore I copied the c library found here into a directory and created a test program main.c:
#include "Picaso_const4D.h"
#include "Picaso_Serial_4DLibrary.h"
int main(int argc,char *argv[])
{
OpenComm("/dev/ttyUSB0", B115200); // Matches with the display "Comms" rate
gfx_BGcolour(0xFFFF);
gfx_Cls();
gfx_CircleFilled(120,160,80,BLUE);
while (1) {}
}
Now when I do gcc -o main main.c its says
main.c:2:37: fatal error: Picaso_Serial_4DLibrary.h: No such file or
directory
So I try linking it:
gcc main.c -L. -lPICASO_SERIAL_4DLIBRARY
which gives me the same error. Then I tried to create a static library:
gcc -Wall -g -c -o PICASO_SERIAL_4DLIBRARY PICASO_SERIAL_4DLIBRARY.C
which gives me this:
PICASO_SERIAL_4DLIBRARY.C:1:21: fatal error: windows.h: No such file
or directory compilation terminated.
What am I doing wrong? the git page clearly says this library is created for people who do not run windows.
Thanks in advance!
You're not getting a linker error; you're getting a preprocessor error. Specifically, your preprocessor can't find Picaso_Serial_4DLibrary.h. Make sure that it's in your include path; you can add directories to your include path using the -I argument to gcc.
You've had two problems. First was the picaso_whatever.h file that couldn't be found. You fixed that with the -I you added. But, now, the picaso.h wants windows.h
What are you building on? WinX or BSD/Linux?
If you're compiling on WinX, you need to install the "platform sdk" for visual studio.
If you're using mingw or cygwin, you need to do something else.
If on WinX, cd to the C: directory. Do find . -type f -name windows.h and add a -I for the containing directory.
If under Linux, repeat the find at the source tree top level. Otherwise, there is probably some compatibility cross-build library that you need to install.
Or, you'll have to find WinX that has it as Picaso clearly includes it. You could try commenting out one or more of the #include's for it and see if things are better or worse.
If you can't find a real one, create an empty windows.h and add -I to it and see how bad [or good] things are.
You may need the mingw cross-compiler. See https://forums.wxwidgets.org/viewtopic.php?t=7729
UPDATE:
Okay ... Wow ... You are on the right track and close, but this is, IMO, ugly WinX stuff.
The primary need of Picaso is getting a serial comm port connection, so the need from within windows.h is [thankfully] minimal. It needs basic boilerplate definitions for WORD, DWORD, etc.
mingw or cygwin will provide their own copies of windows.h. These are "clean room" reimplementations, so no copyright issues.
mingw is a collection of compile/build tools that let you use gcc/ld/make build utilities.
cygwin is more like: I'd like a complete shell-like environment similar to BSD/Linux. You get bash, ls, gcc, tar, and just about any GNU utility you want.
Caveat: I use cygwin, but have never used mingw. The mingw version of windows.h [and a suite of .h files that it includes underneath], being open source, can be reused by other projects (e.g. cygwin, wine).
Under Linux, wine (windows emulator) is a program/suite that attempts to allow you to run WinX binaries under Linux (e.g. wine mywinpgm).
I git cloned the Picaso library and after some fiddling, I was able to get it to compile after pointing it to wine's version of windows.h
Picaso's OpenComm is doing CreateFile [a win32 API call]. So, you'll probably need cygwin. You're opening /dev/ttyUSB0. /dev/* implies cygwin. But, /dev/ttyUSB0 is a Linux-like name. You may need some WinX-style name like "COM:" or whatever. Under the cygwin terminal [which gives you a bash prompt], do ls /dev and see what's available.
You can get cygwin from: http://cygwin.com/ If you have a 64 bit system, be sure to use the 64 bit version of the installer: setup-x86_64.exe It's semi-graphical and will want two directories, one for the "root" FS and one to store packages. On my system, I use C:\cygwin64 and C:\cygwin64_packages--YMMV.
Note that the installer won't install gcc by default. You can [graphically] select which packages to install. You may also need some "devel" packages. They have libraries and .h files that a non-developer wouldn't need. As, docs mention, you can rerun the installer as often as you need. You can add packages that you forgot to specify or even remove ones that you installed that you don't need anymore.
Remember that you'll need to adjust makefile -I and/or -L option appropriately. Also, when building the picaso library, gcc generated a ton of warnings about overflow of a "large integer". The code was doing:
#define control_code -279
unsigned char buf[2];
buf[0] = control_code >> 8;
buf[1] = control_code;
The code is okay, and the warning is correct [because the code is sloppy]. If the code had done:
#define control_code -279
unsigned char buf[2];
buf[0] = (unsigned) control_code >> 8;
buf[1] = (unsigned) control_code;
it probably would have been silent. Use -Wno-overflow in your Makefile to get rid of the warnings rather that edit 50 or so lines
I'm trying to write a simple syntax checker for C code using the frontend available in libclang. Due to deployment concerns, I need to be able to statically link all the libraries in libclang, and not pass around the .so file that has all the libraries.
I'm building clang/llvm from source, and in llvm/Release+Asserts/lib I have a bunch of .a files that I think I should be able to use, but it never seems to work (the linker spews out thousands of errors about missing symbols). However, when I compile it using the libclang.so also present in that directory as follows:
clang main.c -o bin/dlc -I../llvm/tools/clang/include -L../llvm/Release+Asserts/lib/ -lclang
Everything seems to work well.
What is the minimum set of .a files I need to include to make this work? I've tried including absolutely all of the .a files in the build output directory, with them provided to clang/gcc in different orders, without any success. I only need the functions mentioned in libclang's Index.h, but there don't seem to be any resources or documentation on what the various libclang*.a files are for. It would be very helpful to know which files libclang.so pulls in.
The following is supposed to work, as long the whole project has all static libraries (I counted 116 in my Release/lib directory).
clang main.c -o bin/dlc -I../llvm/tools/clang/include ../llvm/Release/lib/*.a
[edit: clang main.c -o bin/dlc -I../llvm/tools/clang/include ../llvm/Release/lib/libclang.a ../llvm/Release/lib/*.a]
Note that the output binary is not static, so you don't need any -static flag for gcc or ld, if you're using this syntax.
If that doesn't work you might need to list the libraries in order: if some library requires a function available in another library, then it may be necessary to list it first in the command line. See comments about link order at:
http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Link-Options.html#Link-Options
I need help to compile a script ("iterator.c") into a DLL. I can't use VS2010 since it does not support the features added to C in the C99 standard (I'm using "complex.h" but VB doesn't support it).
I've been looking for a substitute but all I've found is GCC which I don't know how to install/use (really, I've spent like half an hour reading through the documentation and I don't even understand how am I supposed to install it), and Cygwin, which I've already installed but I don't know how to use either. Also, I've installed MinGW but I think it's the same as Cygwin more or less, and I still don't know how to make a DLL.
It's not like I've been all lazy and haven't even tried it, it's just that these compilers aren't like nothing I've ever used before (mostly Python IDLE and Visual Studio, which make things pretty easy for you). I'm kind of lost.
Could someone give me some advice on how to use this tools to make a DLL that I can access from another script? It is really important.
Thank you in advance.
You must place __declspec(dllexport) in front of the method you wish to export such as, you could #define this to max it easier
EXPORT_DLL void hello() { ... }
To compile the dll use
gcc -c -mno-cygwin mydll.c
gcc -shared -o mydll.dll mydll.o -Wl,--out-implib,libmylib.dll.a
then to attach
gcc -o myexe.exe test.o mydll.dll
EDIT: Forgot the most important piece, you need to make a mydll.h file to include your method definition so the compiler knows to reserve a spot for the linker to fill in later on. It's as simple as
#ifndef MYDLL_H
#define MYDLL_H
extern "C" __declspec(dllexport)
#define EXPORT_DLL __declspec(dllexport)
EXPORT_DLL void hello();
#endif
well i have a few Cpp source and header files, and the header files have include statements in the form,
#include<include/config.h>
#include<include/controls.h>
the thing is im using gcc on windows and it says no such file or directory as the windows style paths has '/' and not '\' ,
so i changed the path to include\config.h but again, the problem is config.h has many header files included in it with the similar unix path style, and its not feasible to change the paths in all the header files cos its a library and there are 100s of such headers, is there any way to compile this using GCC (minGW) ??
Thanks :)
this may sound like a silly problem, sorry if it is!!..
I don't think the direction of the / is the problem here. Windows should convert between the two for you when calling its API precisely for the purposes of (some) unix compatibility.
I think the problem is the include path. Try compiling your program with
gcc -o output.exe -I"c:\path\to\directory\above\include" file.c
So that in the directory you specify with the include flag, there is a subdirectory "include" containing your headers. This assumes all your paths in your other headers are relative to this.
config.h and controls.h are not standard header files. Try this instead:
#include "include/config.h"
#include "include/controls.h"
Even better would be to use the command line to specify the include directory and use
#include "config.h"
#include "controls.h"
Probably mingw uses the same option as all other c compilers: (compiler name) -I(directory name)...
As others have stated, / vs. \ is a non-issue. Even Microsoft compilers and utilities accept / everywhere. The use of \ is a historical mistake, perpetrated needlessly.
A good discussion of your issue can be seen here:
How to generate a OS independent path in c++
Don't change forward slash / to back-slash \ - you are making the compiler to interpret the next character as a special character \c. GCC has no problem dealing with UNIX-style paths on Windows. The problem is probably the lack of -I directive to the compiler - something like -I. to search for files in current and sub-directories.