Hi, all!

I just stumbled across a (newbie?) question about including header files. (I'm just getting familiar with KDevelop (5.6.2) C with Debian, was using Visual-Studio VB.net and C# with Windows until now.)

I started a new session "Rheinwerk OpenBook", added a new project from template "Standard - Terminal - CMake C". The "hello world" was displayed in the out window after "Build" and "Execute". The project was set up in /home/miriki/projects/kdevelop/rheinwerk_openbook/hallo_x/.

Then I replaced the main.c content with another source from Rheinwerk OpenBook Linux Programmierung: 14.4.6 hallo_x.c (scroll a bit down, extended version of source) and added a new source my_delay.h into the project dir, too. The project still was built and linked without problems.

But the header file is used throughout various projects in the book and so I decided to create a "KDevelop global" include directory for this and other projects in the future in /home/miriki/projects/kdevelop/include. Then I added that directory under "Project - Open Configuration - Language Support - Includes/Imports" as a new entry. Additionally I inserted a new line into the CMakeLists.txt:

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target_link_libraries(hallo_x X11)

But the "Build" now errors out with

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/home/miriki/projects/kdevelop/rheinwerk_openbook/hallo_x/build> make -j4
Scanning dependencies of target hallo_x
[ 50%] Building C object CMakeFiles/hallo_x.dir/main.c.o
/home/miriki/projects/kdevelop/rheinwerk_openbook/hallo_x/main.c:9:10: fatal error: my_delay.h: No such file or directory
    9 | #include "my_delay.h"
      |          ^~~~~~~~~~~~
compilation terminated.
make[2]: *** [CMakeFiles/hallo_x.dir/build.make:82: CMakeFiles/hallo_x.dir/main.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:95: CMakeFiles/hallo_x.dir/all] Error 2
make: *** [Makefile:149: all] Error 2
*** Failure: Exit code 2 ***

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miriki@lxdeb1130:~/projects/kdevelop/include$ ls -la
insgesamt 20
drwxr-xr-x 2 miriki miriki 4096  8. Jul 09:27 .
drwxr-xr-x 6 miriki miriki 4096  8. Jul 09:27 ..
-rw-r--r-- 1 miriki miriki  657  6. Jul 20:12 my_delay.h
-rw-r--r-- 1 miriki miriki 5233  3. Jul 18:21 vroot.h

So my questions actually would be:
a) Is the "Language Support" section the correct place to add the .h file(s)?
b) If yes, what went wrong? Otherwise, what else to do?
c) Is there a global include dir for KDevelop or do I have to set that up for each and every project again?
d) Same with libraries for the Linker: Every time into the CMakeLists.txt? Or is there a "global" place?

Michael

Hi!

If you write #include "my_delay.h" it expects the file in the current folder of the including file. Read it as "./my_delay.h". So either provide an absolute path "/home/miriki/projects/kdevelop/include/my_include.h" or use <> and "#include <my_delay.h>" like "<stdio.h>", etc. which should work if you added your include directory correctly.
If you write your own Makefiles, you must include this path yourself with -I /home/miriki/projects/kdevelop/include. (big i, not L or 1)

koffeinfriedhof wrote:If you write your own Makefiles, you must include this path yourself with -I /home/miriki/projects/kdevelop/include. (big i, not L or 1)

Thanks for your answer, but... forgive my dumbness , but: How?

I compiled that source at the CLI according to the Rheinwerk Page:

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gcc -o hallo_x main.c -L/usr/X11R6/lib -lX11

(hallo_x.c changed to main.c)
But that was easy, of course, because the my_delay.h resided in the same / actual directory.
After moving the my_delay.h to the separate directory I used:

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gcc -o hallo_x main.c -I /home/miriki/projects/kdevelop/include/ -L/usr/X11R6/lib -lX11

and that worked with both using "" and <> at the #include.

But... changing into the Subdir "build" and call "make":

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[...] fatal error: my_delay.h: Datei oder Verzeichnis nicht gefunden [...]

And I thought setting that path in die "Language Support" would result in producing the needed -I /hom... extension for the command line or a line in the managed Make files or whatever. Or am I supposed to edit the build/Makefile? That's auto-generated, isn't it? There are settings for CMAKE_SOURCE_DIR and CMAKE_BINARY_DIR in lines 70 and 73 though...

Michael

The Makefile is generated from cmake (if you didn't change it). So you have to provide your include directory by changing CMakeLists.txt like

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target_include_directories(hallo_x PRIVATE ${YOUR_DIRECTORY})
set(SOURCES hallo_x.c another_file.c ${YOUR_DIRECTORY}/my_include.h)


The first adds the -I line, the second tells cmake to parse this file as part of your project.

I'm not that used to cmake as I still write Makefiles for C myself and only use it with Qt which needs other variables, but that should do it.

koffeinfriedhof wrote:changing CMakeLists.txt like [...]

Yay, fully hit! I now have a file with:

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cmake_minimum_required( VERSION 3.0 )
project( hallo_x LANGUAGES C )
add_executable( hallo_x main.c )
target_include_directories( hallo_x PRIVATE ~/projects/kdevelop/include/ )
set( SOURCES hallo_x.c )
target_link_libraries( hallo_x X11 )
install( TARGETS hallo_x RUNTIME DESTINATION bin )

I just replaced the ${YOUR_DIRECTORY} parts with the real path of ~/projects/kdevelop/include/. Ah, and after first success I ommitted the 2nd source file in the set(SOURCES command. And now the "Build" produces (after a "Clear"):

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/home/miriki/projects/kdevelop/rheinwerk_openbook/hallo_x/build> make -j4
[ 50%] Building C object CMakeFiles/hallo_x.dir/main.c.o
[100%] Linking C executable hallo_x
[100%] Built target hallo_x
*** Finished ***

Using the ${xxx} way would require to set a variable with that value methinks? How would that be done?

And still the question: What is the point in setting the include path in the project configuration, in the ide settings that is?

Michael

I think the language support is a global setting for the tools providing code completion, syntax and logical checking, etc. Depending on what you have installed (cppcheck, clang, …) you can set include folders individually. KDevelop is a modular tool and depends on what you did install and which Plugins you did enable. There are a lot of different tools like git, bazaar for versioning, valgrind, gdb, clang for code checking and debugging, etc.