char* not valid syntax in WDK?

[Saduff]

For some reason the WinDDK thinks this is not valid syntax:

char* Hello = "Hello World!";

The build utility gives these errors:

error C2143: syntax error : missing ';' before 'type'

error C2065: 'Hello' : undeclared identifier

I was using the x86 WinXP Free Build Environment. The code is in C.

Also, is char* correct type to pass as PCHAR to API?

[Killboy]

Shouldn't you be using WCHAR and RTL_CONSTANT_STRING?

Which API do you need to use that takes a PCHAR btw?

[Jeremy__]

For some reason the WinDDK thinks this is not valid syntax:

char* Hello = "Hello World!";

The build utility gives these errors:

I was using the x86 WinXP Free Build Environment. The code is in C.

Also, is char* correct type to pass as PCHAR to API?

Lol, I hate this problem. I spent a while looking at this forever trying to make sense of it when I encountered it. It definitely confuses C++ programmers writing C drivers.. In C all variables must be declared before the executable statements. - I bet this is your problem; if not, we obviously need more information. If this doesn't work, check to assure the preceding line is teriminated with a semi-colon.

int foo()
{
 return 0;
}int main()
{
 foo();
 int i = 0; //This is invalid because execution occurs vefore vairable declaration.
}

This is valid:

int foo()
{
 return 0;
}int main()
{
 int i = 0;
 foo();
}

IIRC, PCHAR is a char*

/>http://msdn.microsoft.com/en-us/library/dd440601.aspx

typedef CHAR* PCHAR;

Edited August 9, 2011 by Jeremy__

[Saduff]

In C all variables must be declared before the executable statements.

Yup, that was it. Thanks Jeremy.

I had this line before the Hello var:

DriverObject->DriverUnload = DriverUnload;

But I think this applies only to initialized variables, because if you look in this thread,

you can see that I declare variables later in the code, but it compiles fine. Look at these variables for example:

static char buffer[0x78];
int i;
static LARGE_INTEGER byteOffset;

Shouldn't you be using WCHAR and RTL_CONSTANT_STRING?

Which API do you need to use that takes a PCHAR btw?

I'm trying to use "VidDisplayString" and "VidDisplayStringXY" exported in bootvid.dll.

These are undocumented APIs though, so the PCHAR type may be incorrect. I just found a header file, where it was prototyped with PCHAR.

Most documented APIs use UNICODE_STRING and I've also seen PUCHAR. This one might be PUCHAR instead of PCHAR as well.

-- EDIT --

No, PCHAR is correct. The API is working as expected.

It prints "Hello World!" on the boot screen.

Edited August 9, 2011 by Saduff

[Killboy]

What is the build process like with C++? I read a guide about soem of the pitfalls of using C++ but I imagine if you just use the C subset it shouldn't be a problem?

You could then use some of the useful features like being able to declare variables anywhere (e.g. in for loops) or

compile time constants without having to use #define

[Saduff]

I tried C++, but it's giving a lot of errors, so I just went with C.

And most, if not all, of the example projects in WDK are in C.

I'm new to this stuff, so I don't know how to fix it.

Haven't been coding in C/C++ for a long time either.

[Jeremy__]

I tried C++, but it's giving a lot of errors, so I just went with C.

And most, if not all, of the example projects in WDK are in C.

I'm new to this stuff, so I don't know how to fix it.

Haven't been coding in C/C++ for a long time either.

Yeah, C++ is a real pain in kernel mode. At least I found, plus usually an OOP design isn't nearly as critical as it would be in usermode.

[GamingMasteR]

What is the build process like with C++? I read a guide about soem of the pitfalls of using C++ but I imagine if you just use the C subset it shouldn't be a problem?

You could then use some of the useful features like being able to declare variables anywhere (e.g. in for loops) or

compile time constants without having to use #define

Yes, it's more comfortable for me to use C++ compiler. I use VC++ 9.0 compiler and VS 2010 as IDE.

[atom0s]

Yes, it's more comfortable for me to use C++ compiler. I use VC++ 9.0 compiler and VS 2010 as IDE.

Any reason you aren't using VS2010's compiler? Kinda odd you'd download 2010 just for the IDE and not use the compiler too.

[GamingMasteR]

Ops sorry for the mistake , I actually use VC++ 10.0