Why Qt creator say "use of undeclared identifier 'QSslSocket'", but it exists.

senmx

error: use of undeclared identifier 'QSslSocket'

code:

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QSslSocket>

int main(int argc, char *argv[]) {

    qDebug() << "Device supports OpenSSL: " << QSslSocket::supportsSsl();

    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);

    return app.exec();
}

I tried:

1. check in /usr/local/Qt-5.15.1-android/include

[sen@x include]$ find . -type f -name "qsslsocket.h"
./QtNetwork/qsslsocket.h

2. No problem in the old version(Qt 5.13.2)

test.pro:

QT += quick
QT += network

CONFIG += c++11
...

jsulm

@senmx When do you get this error: while building your project?

senmx

@jsulm No, It hasn't been compiled yet, and qt creator reports an error directly.

jsulm

@senmx OK, then this comes from code model (clang) - it often reports false positive for what ever reason. If you do not want to use it disable the plug-in ClangCodeModel in Help/About Plugins...

senmx

@jsulm Thanks. I found that using the old version is normal, I don't know why. My new version of qt is compiled by myself after downloading the opensource code, and there is this header file under it.

Pablo J. Rogina

@senmx as a side note, if that's the whole code of your "main.cpp", the #include <QSslSockect> statement seems superfluous given there are no references to such class later in the code.

senmx

@Pablo-J-Rogina Thanks.This is all the code, the old version is normal. I just write a test code casually, and raise this question by the way.

SGaist

Hi,

Since you build Qt yourself, did you activate the OpenSSL option ?

senmx

@SGaist What option activate and how?
This is my compile shell:

#!/bin/bash
#https://doc.qt.io/qt-5/android-building.html

cd /home/sen/soft/qt-everywhere-src-5.15.1

./configure -xplatform android-clang -prefix /usr/local/Qt-5.15.1-android --disable-rpath -nomake tests -nomake examples -android-ndk $ANDROID_NDK_HOME -android-sdk $ANDROID_SDK_HOME -no-warnings-are-errors
make -j12
make install

SGaist

You have the complete list of option if you call configure --help.

You should also check the configure summary to see what options/features are enabled.

And finally, if you want to build for Android with OpenSSL, you need an Android build of OpenSSL.

senmx

./configure --help
...
-no-openssl .......... Do not use OpenSSL [default on Apple and WinRT]
-openssl-linked ...... Use OpenSSL and link to libssl [no]
-openssl-runtime ..... Use OpenSSL and dynamically load libssl [auto]

I have now turned on this option and recompile

  1 #!/bin/bash
  2 #https://doc.qt.io/qt-5/android-building.html
  3 #https://doc.qt.io/qt-5/ssl.html
  4 
  5 cd /home/sen/soft/qt-everywhere-src-5.15.1
  6 make clean
  7 OPENSSL_LIBS='-L/home/sen/github/c/openssl-1.1.1g -lssl -lcrypto' ./configure -xplatform android-clang -prefix /usr/local/Qt-5.15.1-android --disable-rpath -nomake tests -nomake examples -android-ndk $ANDROID_NDK_HOME -android-sdk $AND    ROID_SDK_HOME -no-warnings-are-errors -openssl-linked
  8 make -j12
  9 make install

on configure:

ERROR: Feature 'openssl-linked' was enabled, but the pre-condition '!features.securetransport && !features.schannel && libs.openssl' failed.

jsulm

@senmx Is /home/sen/github/c/openssl-1.1.1g the Android build?
Check the config.log file to see why exactly it failed.

senmx

@jsulm config.log:
https://drive.google.com/file/d/1lvrOXPgVWjvnfGV5U7TaMqPEJYh0leLF/view?usp=sharing

jsulm

@senmx You did not answer my question.

Did you check the config.log by yourself first?
Because if you check it you see

> main.cpp:2:10: fatal error: 'openssl/ssl.h' file not found
> #include <openssl/ssl.h>

So, it could not find SSL header.

senmx

@jsulm
I saw it, but I didn’t understand it. The first thing I saw from top to bottom was:

> main.cpp:7:8: error: Intel CET not available
> # error Intel CET not available
> ^
> 1 error generated.
> make: *** [Makefile:191ï¼šmain.o] é”™è¯¯ 1
test config.qtbase.tests.intelcet FAILED

Anyway, something is missing, I don’t know what is missing.

Could not find openssl/ssl.h,but:

[sen@x openssl]$ find /usr/include/openssl/ -type f -name "ssl.h"
/usr/include/openssl/ssl.h

I have compiled link library files in this directory:

/home/sen/github/c/openssl-1.1.1g

libssl_1_1.so
libcrypto_1_1.so

SGaist

How did you build OpenSSL for Android ?

senmx

@SGaist
according to Qt doc:

#!/bin/sh

export HOST=linux-x86_64
export PATH="$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/$HOST/bin":$PATH

cd /home/sen/github/c/openssl-1.1.1g
./Configure shared android-arm -D__ANDROID_API__=21
make -j12 SHLIB_VERSION_NUMBER= SHLIB_EXT=_1_1.so build_libs

SGaist

Then why are you mixing your system installation with your custom OpenSSL build.

By the way, your Intel CET is likely due to a line that starts with a #. My guess is that this is a comme but Python style rather than C/C++ style.

senmx

@SGaist The config.log above is the log of build qt-opensource, not openssl.Myself OpenSSL build is arm binding.

SGaist

Can you provide the complete OpenSSL checks part ?