Compiler errors when including setupapi.h in hello world app

Question

I'm trying to debug some C# P/Invoke problem with 32/64 bit using the SetupDiGetDeviceInterfaceDetail function. This involves analysing the SP_DEVICE_INTERFACE_DETAIL_DATA structure. For this, I tried to write a simple C++ program to see the data that's not documented. My C skills aren't sufficient to read the structure sizes from the definitions.

Here's the code for a new C++ Windows console application created with Visual Studio 2017:

#include "pch.h"
#include <iostream>
#include <Setupapi.h>

int main()
{
    std::cout << "Size: " << sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA) << "\n";
}

As soon as I add the third include, I get 1600+ compiler errors about syntax errors within Microsoft files – missing semicolons, type specifiers and other stuff, spreading over several files like setupapi.h, prsht.h, dpa_dsa.h or commctrl.h. That's well outside my capabilities. Looks like Microsoft has delivered a huge mess. Wondering how Visual Studio was compiled if C++ programming is always like this.

What's wrong here? Why can't I just include that header file as suggested in the documentation?

Is there another way to find out what that sizeof expression would resolve to?

@RichardCritten Thanks, that helped. I could accept it if it was an answer instead of a comment. How should I know this? — ygoe
– ygoe, Commented Dec 20, 2019 at 23:04
Am not sure how you should know this (without some research). From experience: all common type definitions are in <windows.h> header file. Additional header files for specific functionality don't redefine the common types they instead need <windows.h> included 1st to provide them. — Richard Critten
– Richard Critten, Commented Dec 20, 2019 at 23:07
@ygoe ”How should I know this?” By reading output of the compiler. See Output IDE panel, switch the “Show output from” dropdown to “Build”. The first error you’re getting without <windows.h> points to this line in SetupAPI.h: typedef GUID *LPGUID; The GUID identifier has wavy red underline, move mouse there and you’ll see a tooltip saying “identifier GUID is undefined”. — Soonts
– Soonts, Commented Dec 20, 2019 at 23:19

Soonts · Accepted Answer · 2019-12-20 23:05:14Z

1

Here's a fixed version:

#include <iostream>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <Setupapi.h>

int main()
{
    std::cout << "Size: " << sizeof( SP_DEVICE_INTERFACE_DETAIL_DATA ) << "\n";
}

It prints 6, however that's not true, unfortunately for you that structure is variable-length. It's defined like this:

#define ANYSIZE_ARRAY 1
struct SP_DEVICE_INTERFACE_DETAIL_DATA_W
{
    DWORD  cbSize;
    WCHAR  DevicePath[ ANYSIZE_ARRAY ];
}

The length varies depending on data.

answered Dec 20, 2019 at 23:05

Soonts

22.3k11 gold badges68 silver badges147 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

ygoe Over a year ago

That's okay, I need the value of sizeof because that's what must be put in the cbSize field. When using this API from C# I have to convert the relevant structures to managed code that behaves exactly the same, no matter what it means. I wasn't sure if the array counts by content or denotes a pointer. Also, ANYSIZE_ARRAY didn't make sense to me and the value was unclear.

Collectives™ on Stack Overflow

Compiler errors when including setupapi.h in hello world app

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related