[C++] Error linking the util/cancel.h

[tungdsefastec]

Describe the usage question you have. Please include as many useful details as possible.

I tried to use arrow and parquet into c++ project which I use Qt framework. In the cmakefiles, the include directory is defined by ${CMAKE_SOURCE_DIR}/dependencies/apache-arrow/include. The compiler is the MSVC 16.
The error I got is "dependencies\apache-arrow\include\arrow/util/cancel.h(109): error C2143: syntax error: missing ')' before 'public' "

Component(s)

C++

[raulcd]

Could you give more details on how are you building Arrow? How are you downloading it? What version of Arrow are you using? From my understanding MSVC 16 is out of support and uses C++14 as its standard, C++ 17 has been required for Arrow for the last 2.5 years (#13991) but I am unsure if that's the issue without more details.

[tungdsefastec]

I used vcpkg for downloading the package. The version of the arrow is 19.0.1. Actually, the MSVC 16 does support the C++17, and we are currently using C++ 17 for our project. We suspect that it conflicts with the qcoreapplication.h. I can build without errors if not including, or putting the arrow header before the qcoreapplication.h.
I made a simple example to check.
With this version, it will give error.

#include <iostream>
#include <QCoreApplication>
#include "arrow/io/file.h"
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    std::cout << "nothing to show";
    a.exec();
}

However, if I put the "arrow/io/file.h" before the QCoreApplication, it will be fine.

#include <iostream>
#include "arrow/io/file.h"
#include <QCoreApplication>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    std::cout << "nothing to show";
    a.exec();
}

[kou]

Could you show full build log of the test program?

[tungdsefastec]

Here is the compile output.

07:07:25: Starting: "C:\Qt\Tools\CMake_64\bin\cmake.exe" --build D:/1.Work/1.Code/untitled/build/Desktop_Qt_6_6_3_MSVC2019_64bit-Release --target all
[1/4 8.9/sec] Automatic MOC and UIC for target untitled
[2/4 14.3/sec] Building CXX object CMakeFiles\untitled.dir\untitled_autogen\mocs_compilation.cpp.obj
[3/4 2.8/sec] Building CXX object CMakeFiles\untitled.dir\main.cpp.obj
FAILED: CMakeFiles/untitled.dir/main.cpp.obj 
C:\PROGRA~2\MICROS~2\2019\COMMUN~1\VC\Tools\MSVC\1429~1.301\bin\HostX64\x64\cl.exe  /nologo /TP -DQT_CORE_LIB -DQT_NO_DEBUG -DUNICODE -DWIN32 -DWIN64 -D_ENABLE_EXTENDED_ALIGNED_STORAGE -D_UNICODE -D_WIN64 -ID:\1.Work\1.Code\untitled\apache-arrow\include -external:ID:\1.Work\1.Code\untitled\build\Desktop_Qt_6_6_3_MSVC2019_64bit-Release\untitled_autogen\include -external:IC:\Qt\6.6.3\msvc2019_64\include\QtCore -external:IC:\Qt\6.6.3\msvc2019_64\include -external:IC:\Qt\6.6.3\msvc2019_64\mkspecs\win32-msvc -external:W0 /DWIN32 /D_WINDOWS /EHsc /O2 /Ob2 /DNDEBUG -std:c++17 -MD -Zc:__cplusplus -permissive- -utf-8 /showIncludes /FoCMakeFiles\untitled.dir\main.cpp.obj /FdCMakeFiles\untitled.dir\ /FS -c D:\1.Work\1.Code\untitled\main.cpp
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(109): error C2143: syntax error: missing ')' before 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(109): error C2143: syntax error: missing ';' before 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(109): error C2059: syntax error: 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(109): error C2059: syntax error: ')'
ninja: build stopped: subcommand failed.
07:07:26: The process "C:\Qt\Tools\CMake_64\bin\cmake.exe" exited with code 1.
Error while building/deploying project untitled (kit: Desktop Qt 6.6.3 MSVC2019 64bit)
When executing step "Build"

[kou]

What Apache Arrow C++ version are you using?

[tungdsefastec]

I used arrow 19.0.1

[kou]

arrow/cpp/src/arrow/util/cancel.h

Line 109 in 272715f

/// therefore the child process will need to call RegisterCancellingSignalHandler()

The target line is a comment line. Did you change arrow/util/cancel.h?

[tungdsefastec]

Sorry. This is updated compile output for arrow version 19.0.1.

[1/2 0.8/sec] Building CXX object CMakeFiles\untitled.dir\main.cpp.obj
FAILED: CMakeFiles/untitled.dir/main.cpp.obj 
C:\PROGRA~2\MICROS~2\2019\COMMUN~1\VC\Tools\MSVC\1429~1.301\bin\HostX64\x64\cl.exe  /nologo /TP -DQT_CORE_LIB -DQT_NO_DEBUG -DUNICODE -DWIN32 -DWIN64 -D_ENABLE_EXTENDED_ALIGNED_STORAGE -D_UNICODE -D_WIN64 -ID:\1.Work\1.Code\untitled\apache-arrow\include -external:ID:\1.Work\1.Code\untitled\build\Desktop_Qt_6_6_3_MSVC2019_64bit-Release\untitled_autogen\include -external:IC:\Qt\6.6.3\msvc2019_64\include\QtCore -external:IC:\Qt\6.6.3\msvc2019_64\include -external:IC:\Qt\6.6.3\msvc2019_64\mkspecs\win32-msvc -external:W0 /DWIN32 /D_WINDOWS /EHsc /O2 /Ob2 /DNDEBUG -std:c++17 -MD -Zc:__cplusplus -permissive- -utf-8 /showIncludes /FoCMakeFiles\untitled.dir\main.cpp.obj /FdCMakeFiles\untitled.dir\ /FS -c D:\1.Work\1.Code\untitled\main.cpp
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(112): error C2143: syntax error: missing ')' before 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(112): error C2143: syntax error: missing ';' before 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(112): error C2059: syntax error: 'public'
D:\1.Work\1.Code\untitled\apache-arrow\include\arrow/util/cancel.h(112): error C2059: syntax error: ')'
ninja: build stopped: subcommand failed.
16:34:48: The process "C:\Qt\Tools\CMake_64\bin\cmake.exe" exited with code 1.
Error while building/deploying project untitled (kit: Desktop Qt 6.6.3 MSVC2019 64bit)
When executing step "Build"
16:34:48: Elapsed time: 00:01.

[kou]

Could you generate pre-processed result by -P -C instead of -c?

C:\PROGRA~2\MICROS~2\2019\COMMUN~1\VC\Tools\MSVC\1429~1.301\bin\HostX64\x64\cl.exe  /nologo /TP -DQT_CORE_LIB -DQT_NO_DEBUG -DUNICODE -DWIN32 -DWIN64 -D_ENABLE_EXTENDED_ALIGNED_STORAGE -D_UNICODE -D_WIN64 -ID:\1.Work\1.Code\untitled\apache-arrow\include -external:ID:\1.Work\1.Code\untitled\build\Desktop_Qt_6_6_3_MSVC2019_64bit-Release\untitled_autogen\include -external:IC:\Qt\6.6.3\msvc2019_64\include\QtCore -external:IC:\Qt\6.6.3\msvc2019_64\include -external:IC:\Qt\6.6.3\msvc2019_64\mkspecs\win32-msvc -external:W0 /DWIN32 /D_WINDOWS /EHsc /O2 /Ob2 /DNDEBUG -std:c++17 -MD -Zc:__cplusplus -permissive- -utf-8 /showIncludes /FoCMakeFiles\untitled.dir\main.cpp.obj /FdCMakeFiles\untitled.dir\ /FS -P -C D:\1.Work\1.Code\untitled\main.cpp

This will generate D:\1.Work\1.Code\untitled\main.i.

[tungdsefastec]

This is the main.i. I couldn't upload the main.i. So I convert it into the .txt instead
main.txt

[kou]

Thanks. I got it.

Qt defines signals macro as public. So the signals parameter name in

arrow/cpp/src/arrow/util/cancel.h

Line 112 in 272715f

Status RegisterCancellingSignalHandler(const std::vector<int>& signals);

is replaced to public. It causes the error because public is a C++ keyword.

How to fix: Define QT_NO_META_MACROS before you include Qt. It prevents defining the signals macro.