Thread: MSVC9 Error?

Hey guys.

I attempted to compile what I have done so far and recived two bizzare messages from the compiler refering to files with the software. The program seems to compile ok without any syntax errors. I really do not know how to get rid of these errors, please help!

main:

Code:

#include "heartrates.h"
#include <iostream>

// main function - begin program execution
//
int main ( void )
{
	HeartRates hr( "", "", 0, 0, 0 );

	std::cin.get(); // prevent console closing in debug state
}

heartrate.h

Code:

#ifndef HEARTRATES_H
#define HEARTRATES_H

#include <string>

class HeartRates
{
public:
	HeartRates ( std::string, std::string, int, int, int );

	void setFirstName ( std::string );
	void setLastName ( std::string );
	void setDay ( int );
	void setMonth ( int );
	void setYear ( int );

	std::string getFirstName() const;
	std::string getLastName() const;
	int getDay() const;
	int getMonth() const;
	int getYear() const;

	int getAge() const;
	int getMaximumHeartRate() const;
	int getTargetHeartRate() const;

private:
	std::string firstName,
		lastName;
	int day,
	     month,
	     year;
};

#endif // heartrates.h

heartrates.cpp ( unfinished )

Code:

#include "heartrates.h"
#include <iostream>

// constructor - ensure data member begin in a legal state
HeartRates::HeartRates ( std::string first, std::string last, 
		         int dy, int mth, int yr )
{
}

The errors:

Code:

c:\program files\microsoft visual studio 9.0\vc\include\codeanalysis\sourceannotations.h(19) : error C2144: syntax error : '__w64 unsigned int' should be preceded by ';'
c:\program files\microsoft visual studio 9.0\vc\include\codeanalysis\sourceannotations.h(19) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

I just pasted this code into a project on GCC and it produced no such errors...FWIW...so either the error was caused by something not posted here or there is something unique about MSVC9....

I don't have that compiler, so I tried plugging it into Dinkumware. It compiled just fine, but that was in one source file and with MSVC 8 and earlier.

I would suspect that you've inadvertently used a name which is a macro or something. Maybe "day", or "year", or "dy"; just try changing all your variable names around, see if that makes a difference.

Failing that, I'd guess your compiler to be broken. There doesn't seem to be anything wrong there that I can see.

---

Incidentally, why does MSVC 7 (and g++) accept and compile this code?

Code:

#include <string>
#include <iostream>

class HeartRates
{
public:
	HeartRates ( std::string, std::string, int, int, int ) {}

	void setFirstName ( std::string );
	void setLastName ( std::string );
	void setDay ( int );
	void setMonth ( int );
	void setYear ( int );

	std::string getFirstName() const;
	std::string getLastName() const;
	int getDay() const;
	int getMonth() const;
	int getYear() const;

	int getAge() const;
	int getMaximumHeartRate() const;
	int getTargetHeartRate() const;

private:
	std::string firstName,
		lastName;
	int day,
	     month,
	     year;
};

// main function - begin program execution
//
int main ( void )
{
	HeartRates hr( "", "", 0, 0, 0 );

	std::cin.get(); // prevent console closing in debug state
}

Shouldn't it give you linker errors because of the undefined functions? Or does that only matter if you use them . . . ? That's quite strange, I would have predicted linker errors.

Originally Posted by dwks

Incidentally, why does MSVC 7 (and g++) accept and compile this code?

There's no linker error, because there is no unresolved symbols. Since you are not calling any of the functions, there is no attempt to look up any of the function names, therefore there is nothing for the linker to complain about.

Originally Posted by dwks

Shouldn't it give you linker errors because of the undefined functions? Or does that only matter if you use them . . . ? That's quite strange, I would have predicted linker errors.

If the functions aren't called, then they don't have to exist. For instance, you implement a non-copyable class like this:

Code:

class noncopyable
{
private:
    noncopyable( const noncopyable & ); // private, no implementation
    noncopyable &operator=( const noncopyable & ); // private, no implementation
};

The only time you MUST implement a function that isn't called anywhere is if it's virtual, since the vtable contains a reference to it.

Interesting. I knew that worked for template classes, but I wasn't aware it worked for ordinary ones too. I guess I'd never tried it before. But of course it does make sense.

I think what's more odd is that MSVC and g++ will compile and run this:

Code:

#include <iostream>

class Test
{
public:
    void foo()
    {   
        std::cout << "Hello World\n";
    }   
};

int main()
{
    Test* t = NULL;
    t->foo();
}

It makes sense once you look into what's happening, but intuitively, you would think it would crash

Microsoft's own code is filled with junk like this:

Code:

ERR SomeClass::Foo()
{
    if( this == NULL )
        // somebody called through a NULL pointer
        return SOME_ERROR;
    ...
    return OK;
}

Guuuuuuh.

Yes, I see what you mean. It's just passing a this pointer which is never dereferenced, but the "t->foo()" syntax makes it look like you are in fact dereferencing it. Tricky.

[edit] Checking explicitly for NULL inside the function seems like a bit of a waste to me, especially if it's left in production code. And anyway, that's one of the easiest ways for me to catch some errors: get a segfault, fire up the debugger, and notice this is 0x0 . . . . [/edit]

The only time you MUST implement a function that isn't called anywhere is if it's virtual, since the vtable contains a reference to it.

Right. I've definitely had this happen to me before.