CMake include external and own headers - c++

Question

I have a CMakelist.txt where i add external header files and lib. files for my build.
Now when I call custom headers ("myown.h") in my main function I get errors when running CMake linking.
So I found out that I have to add my own headers and .cpp to a library with add_library and then add them under target_link_libraries.
However I get a link error while building as long as I want to call the code from my own header.
Does anyone have an idea where the error is or how I can continue?
Here is my CMakelist:
cmake_minimum_required(VERSION 3.0.0)
project(MIELE_OCULUS VERSION 0.1.0)
#Hier weden die include files gefunden
INCLUDE_DIRECTORIES(
C:/Projekte/Cpp/dev/vcpkg/installed/x64-windows/include
)
#Hier werden die lib files gefunden
LINK_DIRECTORIES(
C:/Projekte/Cpp/dev/vcpkg/installed/x64-windows/lib,
C:/Program Files (x86)/Windows Kits/10/Lib/10.0.19041.0/um/x64
)
add_library(
test
testclass.h
testclass.cpp
)
add_executable(MIELE_OCULUS
main.cpp
)
TARGET_LINK_LIBRARIES(MIELE_OCULUS
cpprest_2_10
WS2_32
test
)
UPDATE:
With these changes in CMakelist.txt you can build the program, but after changing the src code or cleaning up the CMake project, linking errors will occur again.
changed CMakelist:
cmake_minimum_required(VERSION 3.0.0)
project(MIELE_OCULUS VERSION 0.1.0)
add_library(
mylib
includes/mylib/testclass.h
includes/mylib/testclass.cpp
)
#Hier weden die include files gefunden
TARGET_INCLUDE_DIRECTORIES(mylib PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/mylib>
$<INSTALL_INTERFACE:include/mylib> # <prefix>/include/mylib
)
INCLUDE_DIRECTORIES(
C:/Projekte/Cpp/dev/vcpkg/installed/x64-windows/include
C:/Projekte/Cpp/dev/Miele_Oculus
)
#Hier werden die lib files gefunden
LINK_DIRECTORIES(
C:/Projekte/Cpp/dev/vcpkg/installed/x64-windows/lib
C:/Program Files (x86)/Windows Kits/10/Lib/10.0.19041.0/um/x64
)
add_executable(MIELE_OCULUS
main.cpp
)
TARGET_LINK_LIBRARIES(MIELE_OCULUS
cpprest_2_10
WS2_32
mylib
)
Here is the verbose output:
Der Buildvorgang wurde am 01.11.2020 16:19:04 gestartet.
Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\ALL_BUILD.vcxproj" auf Knoten "1" (Standardziele).
Das Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\ALL_BUILD.vcxproj" (1) erstellt "C:\Projekte\Cpp\dev\Miele_Oculus\b
uild\ZERO_CHECK.vcxproj" (2) auf Knoten "1" (Standardziele).
InitializeBuildStatus:
"x64\Debug\ZERO_CHECK\ZERO_CHECK.tlog\unsuccessfulbuild" wird erstellt, da "AlwaysCreate" angegeben wurde.
CustomBuild:
Alle Ausgaben sind aktuell.
FinalizeBuildStatus:
Die Datei "x64\Debug\ZERO_CHECK\ZERO_CHECK.tlog\unsuccessfulbuild" wird gelöscht.
Aktualisieren des Timestamps von "x64\Debug\ZERO_CHECK\ZERO_CHECK.tlog\ZERO_CHECK.lastbuildstate".
Die Erstellung von Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\ZERO_CHECK.vcxproj" ist abgeschlossen (Standardziele
).
Das Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\ALL_BUILD.vcxproj" (1) erstellt "C:\Projekte\Cpp\dev\Miele_Oculus\b
uild\MIELE_OCULUS.vcxproj" (3) auf Knoten "1" (Standardziele).
Das Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\MIELE_OCULUS.vcxproj" (3) erstellt "C:\Projekte\Cpp\dev\Miele_Oculu
s\build\mylib.vcxproj" (4) auf Knoten "1" (Standardziele).
InitializeBuildStatus:
"mylib.dir\Debug\mylib.tlog\unsuccessfulbuild" wird erstellt, da "AlwaysCreate" angegeben wurde.
CustomBuild:
Alle Ausgaben sind aktuell.
VcpkgTripletSelection:
Using triplet "x64-windows" from "C:\Projekte\Cpp\dev\vcpkg\installed\x64-windows"
ClCompile:
Alle Ausgaben sind aktuell.
Lib:
Alle Ausgaben sind aktuell.
mylib.vcxproj -> C:\Projekte\Cpp\dev\Miele_Oculus\build\Debug\mylib.lib
AppLocalFromInstalled:
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Bypass -noprofile -File "C:\Projekte\Cpp\d
ev\vcpkg\scripts\buildsystems\msbuild\applocal.ps1" "C:\Projekte\Cpp\dev\Miele_Oculus\build\Debug\mylib.lib" "C:\Proj
ekte\Cpp\dev\vcpkg\installed\x64-windows\debug\bin" "mylib.dir\Debug\mylib.tlog\mylib.write.1u.tlog" "mylib.dir\Debug
\vcpkg.applocal.log"
FinalizeBuildStatus:
Die Datei "mylib.dir\Debug\mylib.tlog\unsuccessfulbuild" wird gelöscht.
Aktualisieren des Timestamps von "mylib.dir\Debug\mylib.tlog\mylib.lastbuildstate".
Die Erstellung von Projekt "C:\Projekte\Cpp\dev\Miele_Oculus\build\mylib.vcxproj" ist abgeschlossen (Standardziele).
InitializeBuildStatus:
Aktualisieren des Timestamps von "MIELE_OCULUS.dir\Debug\MIELE_OCULUS.tlog\unsuccessfulbuild".
CustomBuild:
Alle Ausgaben sind aktuell.
VcpkgTripletSelection:
Using triplet "x64-windows" from "C:\Projekte\Cpp\dev\vcpkg\installed\x64-windows"
ClCompile:
Alle Ausgaben sind aktuell.
Link:
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.27.29110\bin\HostX64\x64\link.exe /ERR
ORREPORT:QUEUE /OUT:"C:\Projekte\Cpp\dev\Miele_Oculus\build\Debug\MIELE_OCULUS.exe" /INCREMENTAL /NOLOGO /LIBPATH:"C:
/Projekte/Cpp/dev/vcpkg/installed/x64-windows/lib" /LIBPATH:"C:/Projekte/Cpp/dev/vcpkg/installed/x64-windows/lib/Debu
g" /LIBPATH:C:/Program /LIBPATH:C:/Program/Debug /LIBPATH:C:/Projekte/Cpp/dev/Miele_Oculus/Files /LIBPATH:C:/Projekte
/Cpp/dev/Miele_Oculus/Files/Debug /LIBPATH:"C:/Projekte/Cpp/dev/Miele_Oculus/(" /LIBPATH:"C:/Projekte/Cpp/dev/Miele_O
culus/(/Debug" /LIBPATH:C:/Projekte/Cpp/dev/Miele_Oculus/x86 /LIBPATH:C:/Projekte/Cpp/dev/Miele_Oculus/x86/Debug /LIB
PATH:"C:/Projekte/Cpp/dev/Miele_Oculus/)" /LIBPATH:"C:/Projekte/Cpp/dev/Miele_Oculus/)/Debug" /LIBPATH:/Windows /LIBP
ATH:/Windows/Debug /LIBPATH:C:/Projekte/Cpp/dev/Miele_Oculus/Kits/10/Lib/10.0.19041.0/um/x64 /LIBPATH:C:/Projekte/Cpp
/dev/Miele_Oculus/Kits/10/Lib/10.0.19041.0/um/x64/Debug /LIBPATH:"C:\Projekte\Cpp\dev\vcpkg\installed\x64-windows\deb
ug\lib" /LIBPATH:"C:\Projekte\Cpp\dev\vcpkg\installed\x64-windows\debug\lib\manual-link" cpprest_2_10.lib WS2_32.lib
Debug\mylib.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.l
ib advapi32.lib "C:\Projekte\Cpp\dev\vcpkg\installed\x64-windows\debug\lib*.lib" /MANIFEST /MANIFESTUAC:"level='asIn
voker' uiAccess='false'" /manifest:embed /DEBUG /PDB:"C:/Projekte/Cpp/dev/Miele_Oculus/build/Debug/MIELE_OCULUS.pdb"
/SUBSYSTEM:CONSOLE /TLBID:1 /DYNAMICBASE /NXCOMPAT /IMPLIB:"C:/Projekte/Cpp/dev/Miele_Oculus/build/Debug/MIELE_OCULUS
.lib" /MACHINE:X64 /machine:x64 MIELE_OCULUS.dir\Debug\main.obj
LINK : fatal error LNK1104: Datei "C:\Projekte\Cpp\dev\Miele_Oculus\build\Debug\MIELE_OCULUS.exe" kann nicht geöffnet w
erden. [C:\Projekte\Cpp\dev\Miele_Oculus\build\MIELE_OCULUS.vcxproj]
Die Erstellung des Projekts "C:\Projekte\Cpp\dev\Miele_Oculus\build\MIELE_OCULUS.vcxproj" ist abgeschlossen (Standardzi
ele) -- FEHLER.
Die Erstellung des Projekts "C:\Projekte\Cpp\dev\Miele_Oculus\build\ALL_BUILD.vcxproj" ist abgeschlossen (Standardziele
) -- FEHLER.
Fehler beim Buildvorgang.
"C:\Projekte\Cpp\dev\Miele_Oculus\build\ALL_BUILD.vcxproj" (Standardziel) (1) ->
"C:\Projekte\Cpp\dev\Miele_Oculus\build\MIELE_OCULUS.vcxproj" (Standardziel) (3) ->
(Link Ziel) ->
LINK : fatal error LNK1104: Datei "C:\Projekte\Cpp\dev\Miele_Oculus\build\Debug\MIELE_OCULUS.exe" kann nicht geöffnet
werden. [C:\Projekte\Cpp\dev\Miele_Oculus\build\MIELE_OCULUS.vcxproj]
0 Warnung(en)
1 Fehler
Verstrichene Zeit 00:00:00.90

Answer 1

Now it works
1:
Adding a header into add_library call doesn't add include directories for the header.
You need to add these directories manually, with INCLUDE_DIRECTORIES or
TARGET_INCLUDE_DIRECTORIES
I added this part:
#Eigene header Dateien include
TARGET_INCLUDE_DIRECTORIES(mylib PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/includes/mylib>
$<INSTALL_INTERFACE:includes/mylib> # <prefix>/includes/mylib
Thanks a lot to Tsyvarev ! :)
2:
The "strange" behavoir was a bad mistake from me, cause I didnt known that i delete the output terminal in windows bevor i start a new build in the command window
Thank you guys!