Why doesn't Qt recognize my header file? cannot open include file No such file or directory

Question

I have the below in my .pro file and I have files that #include "headerhere". For example: #include "StdAfx.h". However I'm getting an

error Cannot open include file: 'StdAfx.h': No such file or directory.

I get the same error whether I use #include "StdAfx.h" or #include "Shared/StdAfx.h". This is extremely frustrating and I can't do any actual work unless Qt starts recognizing my headers. I've found online no solution for this. What is going on?

.pro file has:

HEADERS  += ibproject.h \
Shared/StdAfx.h \
Shared/TwsSocketClientErrors.h \
Shared/TagValue.h \
Shared/shared_ptr.h \
Shared/ScannerSubscription.h \
Shared/OrderState.h \
Shared/Order.h \
Shared/IBString.h \
Shared/HScrollListBox.h \
Shared/Execution.h \
Shared/EWrapper.h \
Shared/EClientSocketBaseImpl.h \
Shared/EClientSocketBase.h \
Shared/EClient.h \
Shared/Contract.h \
Shared/CommonDefs.h \
Shared/CommissionReport.h \
SocketClient/src/EClientSocket.h
ewrappersubclass.h 

INCLUDEPATH += $$PWD/SocketClient
DEPENDPATH += $$PWD/SocketClient

EDIT: why I am getting downvotes? This is a legitimate problem I'm having

Image showing it recognizes and doesn't recognize simultaneously

@john it's currently in `shared/stdafx.h` but to be honest I've copied it and pasted in both the root and the shared folder just to test if it was because I had some syntax wrong. Nope, it doesn't recognize it even when its in both folders — Terence Chow, Apr 27 '13 at 22:37
I don't know QT but have you tried adding the directory with stdafx.h to INCLUDEPATH, something like `INCLUDEPATH += $$PWD` — john, Apr 27 '13 at 22:40
@john I've tried including both `$$PWD` and `$$PWD/Shared` but it didn't help — Terence Chow, Apr 27 '13 at 22:54
this is a perfectly valid question; I'm having the exact same issue. did you find a solution? — johnbakers, Sep 18 '13 at 06:20
@OpenLearner unfortunately not. After a few hiccups restarting it worked..then it didn't work again...It was so frustrating I just redid the project in a different GUI... — Terence Chow, Sep 25 '13 at 22:52
Little bit offtop, but - stdafx.h is a pure MS Visual Studio feature, I think that you shouldn't use it in Qt Creator. — QtRoS, Jan 29 '15 at 09:14

score 13 · Answer 1 · answered Dec 07 '14 at 22:17

I had the same problem as well. The reason was that I use two computers in parallel and the makefile tried to find files at paths as they are set on the previous one. But everything seemed to be fine - as in your case, tooltip when hovering over the include showed me the correct path, also F2 (follow symbol under cursor) navigated me to the correct header.

I thought qmake is re-maked each time I change something in the .pro file, but obviously not.

Just run Build->qmake, it should fix it.

also, qt cannot recognize spaces in the path, pls take this into consideration. — Summer Sun, Sep 18 '17 at 13:19

score 9 · Answer 2 · edited Nov 26 '13 at 17:17

9

You need to update the qmake file.

Build-> Run qmake

edited Nov 26 '13 at 17:17

Lorenz Meyer

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answered Nov 26 '13 at 16:53

Sirga

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score 3 · Answer 3 · answered Jan 29 '15 at 09:05

3

add in .pro INCLUDEPATH += $$_PRO_FILE_PWD_

answered Jan 29 '15 at 09:05

stephone

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This solved my problem. The project was working well weeks but when I changed compilation kit, one header file was not found anymore. Adding this INCLUDEPATH to *.pro file solved the problem but I do not still understand what happened and why the change had to be done? – Petri Pyöriä Oct 21 '15 at 09:04

score 1 · Answer 4 · answered Mar 08 '18 at 07:45

I have this issue from time to time, mostly when I make a pull request or copy code around.

The easy solution is to delete all qt generated files, and Build->qmake then Rebuild all.

This is a Qt Bug that it does not properly identify files that need to be regenerated and, even though the IDE links everything nicely, that error happens at compile time. The same happens when it generates ui_formname.h header files, some changes are not made effective straight away.

Sometimes, restarting the QtCreator is necessary. Doing the deleting and restarting always solves this exact issue.

Have a nice day!

score 0 · Answer 5 · answered Apr 27 '13 at 23:14

0

The file is not in your include path.

The HEADERS part of a pro file lists header files that the project depends on. These files are considered for processing by moc if they have the Q_OBJECT macro in the class definition. Adding a file to HEADERS does not put it in the include search path.

You also have a stray header (ewrappersubclass.h) because you forgot to escape the end of line.

I suspect that the reason for this is a Windows case sensitivity problem. The compiler is case sensitive but the file system is not; or vice-versa. Such that you #include "shared/stdafx.h" when you should #include "Shared/StdAfx.h".

answered Apr 27 '13 at 23:14

koan

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I've added a screenshot so you can see that I did in fact type the case correctly. My `INCLUDESPATH` does not need to add the `StdAfx.h` because I am including it with `Shared/StdAfx.h`...Any idea why this is happening? – Terence Chow Apr 27 '13 at 23:27
You should look at the Makefile generated with qmake to find out what include path is given to the compiler – koan Apr 29 '13 at 12:43

score 0 · Answer 6 · answered Apr 28 '13 at 09:10

0

It is most likely because of the previous C1189 error, see here.

answered Apr 28 '13 at 09:10

cmannett85

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score 0 · Answer 7 · edited Jan 30 '18 at 07:48

0

I know this post is very old but It just happened to me.

INCLUDEPATH += $$PWD

did the trick. Don't forget to do qmake and then build all.

All the best!

edited Jan 30 '18 at 07:48

O'Neil

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answered Jan 30 '18 at 07:41

kentropy

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Why doesn't Qt recognize my header file? cannot open include file No such file or directory

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