From Ubuntu to Windows: Syntax Error C2059 / C2143

[fem_dev]

I just copy my working Qt project from my Ubuntu 20.04 machine to my Windows 10 x64 machine.

I got two weird compile time errors in my custom header file:

#ifndef MESSAGE_TYPES_H
#define MESSAGE_TYPES_H

typedef enum {
    ERROR = -2, // C2059: syntax error: 'constant'
    WARNING = -1,
    STATUS = 0
} MSG_TYPE; // C2143: syntex error: ';' missing before  '}'

#endif // MESSAGE_TYPES_H

Why it's happening?
How can I fix it?

My systems are:
A)

• Ubuntu 20.04 x64
• Qt Creator 4.12.4
• Qt 5.15
• GCC 9.3 Compiler x64

B)

• Windows 10 x64
• Qt Creator 4.12.4
• Qt 5.15
• MSVC 2019 x64

[mrjj]

Hi
Its a name clash with MSVC 2019
ERROR is defined already.

[fem_dev]

@mrjj Thank you....now its working good!

Second doubt: I was thinking that 'ERROR' inside the custom enum will not clash with MSVC 2019.
Why this happen?

[Christian Ehrlicher]

@fem_dev said in From Ubuntu to Windows: Syntax Error C2059 / C2143:

Why this happen?

Because it's already defined as @mrjj already told you. It's a #define .

[JonB]

@fem_dev
ERROR will be defined in a header file, either an MSVC-specific one or somewhere in some Windows header file. It might be defined in COM.

[fcarney]

You have the option of using mingw in windows (basically gcc for windows). This will help avoid these kinds of problems. YMMV.

[Christian Ehrlicher]

@fcarney said in From Ubuntu to Windows: Syntax Error C2059 / C2143:

This will help avoid these kinds of problems. YMMV.

No, not in this case. ERROR is a define in a windows header.
btw: using uppercase in enums is ... strange

[jsulm]

@fem_dev You can use "enum class" to avoid name clashes:

typedef enum class {
    ERROR = -2, // C2059: syntax error: 'constant'
    WARNING = -1,
    STATUS = 0
} MSG_TYPE;

But then you will need to qualify using enum name:

MSG_TYPE::ERROR;

[J.Hilk]

@Christian-Ehrlicher said in From Ubuntu to Windows: Syntax Error C2059 / C2143:

btw: using uppercase in enums is ... strange

Sadly its mandatory - at least the first letter - if you want to expose your enum to the QML-Engine

[JonB]

@J-Hilk
In fairness, the usual way now for an enum is initial capital followed by smalls, which should avoid the calls with ERROR.

[mrjj]

Hi
Just a note.
I seen many C(not ++) coding standards that say to use all caps for enum values
over the years to follow all caps for constants.

[JonB]

@mrjj
Indeed, that's why I wrote " the usual way now". I think it has changed so that enum constants are like class names. Certainly if you look at https://doc.qt.io/qt-5/qt.html you see all Qt enum values are done that way for their values.

[Christian Ehrlicher]

@jsulm said in From Ubuntu to Windows: Syntax Error C2059 / C2143:

But then you will need to qualify using enum name:
MSG_TYPE::ERROR;

Again: this will not help. It's a define in wingdi.h:

/* Region Flags */
#define ERROR               0
#define NULLREGION          1
#define SIMPLEREGION        2
#define COMPLEXREGION       3
#define RGN_ERROR ERROR

[hskoglund]

About wingdi.h clobbering the global #define-space, Microsoft usually provides an escape hatch, put this

#define NOGDI

somewhere before #include windows.h