Why no C++ in Windows itself?

[Herr Lucifer]

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API
functions. The thing I have noticed is that, 'almost' all system .dll and
..exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't
Microsoft used it in its operating system? Is there a compatibility issue
here that I am not aware of? Or something else?
---
Thanks for comments

[Tom Widmer]

Herr Lucifer wrote:

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API
functions. The thing I have noticed is that, 'almost' all system .dll and
.exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't
Microsoft used it in its operating system? Is there a compatibility issue
here that I am not aware of? Or something else?

How can you tell that they are written in C? Have you examined the
assembler to look for the presence of C++ startup code (such as the
running of global object constructors)? Remember that C++ code need not
dynamically link with the C++ runtime, and it need not present a C++
interface to the outside world.

Tom

[benben]

The GDI system is written in C++, at least.

Herr Lucifer wrote:

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API functions. The thing I have noticed is that, 'almost' all system .dll and .exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't Microsoft used it in its operating system? Is there a compatibility issue here that I am not aware of? Or something else?

How can you tell that they are written in C? Have you examined the
assembler to look for the presence of C++ startup code (such as the
running of global object constructors)? Remember that C++ code need not
dynamically link with the C++ runtime, and it need not present a C++
interface to the outside world.

Tom

[Herr Lucifer]

I don't know what you think of C++, but in its earliest definition, C++ was
called "C with classes". So if there is no class in there, there is no C++
code; it is just pure C....
PS: dependency walker (version 2.1.36668) is able to show functions inside
their classes if their are C++. Take a look if you have VS.NET 2003
-----------------------
"Tom Widmer" <to********@hot mail.com> wrote in message

How can you tell that they are written in C? Have you examined the
assembler to look for the presence of C++ startup code (such as the
running of global object constructors)? Remember that C++ code need not
dynamically link with the C++ runtime, and it need not present a C++
interface to the outside world.

Tom

[David Webber]

"Herr Lucifer" <"\n"HerrLucife r\n@microsoft.c om> wrote in message
news:el******** ******@TK2MSFTN GP10.phx.gbl...

I don't know what you think of C++, but in its earliest definition,
C++ was called "C with classes". So if there is no class in there,
there is no C++ code; it is just pure C....
PS: dependency walker (version 2.1.36668) is able to show
functions inside their classes if their are C++. Take a look if
you have VS.NET 2003

If the fundamental Windows API exported classes then surely it would
only be accessible to programs written in C++.

There *is* a version which exports classes - it is called MFC most
of which is a very thin wrapper around the Windows API. [And it
isn't particularly object-oriented.]

Dave
--
David Webber
Author MOZART the music processor for Windows -
http://www.mozart.co.uk
For discussion/support see
http://www.mozart.co.uk/mzusers/mailinglist.htm

[Carl Daniel [VC++ MVP]]

Herr Lucifer" <"\n wrote:

It is a long time now that I am using "Dependency Walker for Win32"
and navigating through different Dlls in "System32" folder to find my
target API functions. The thing I have noticed is that, 'almost' all
system .dll and .exe
files are written in C and not C++. If C++ is a powerful OO language
and it's much greater than C for large application development, then
why haven't Microsoft used it in its operating system? Is there a
compatibility issue here that I am not aware of? Or something else?

A great deal of Windows, especially in the user-mode components, is written
in C++. It simply exposes a pure-C API since that's the only ABI
(Application Binary Interface) defined for Windows. A C++ API would not be
callable by any language other than C++.

The Kernel is written almost entirely in C, with a very few bits of
assembler here and there.

-cd

[Tom Widmer]

Herr Lucifer wrote:

I don't know what you think of C++, but in its earliest definition, C++ was
called "C with classes". So if there is no class in there, there is no C++
code; it is just pure C....
PS: dependency walker (version 2.1.36668) is able to show functions inside
their classes if their are C++. Take a look if you have VS.NET 2003

Only if they are exported though! The *interface* is C (to allow
interoperabilit y with as many other languages as possible, such as C,
C++, Delphi, VB, etc.), but that doesn't tell you anything about the
language with which the dll is implemented. The DLL code could include
thousands of C++ classes, but the interface still be exposed as pure C.

For example, I've got a C++ DLL that I've written containing lots of
classes but it only exposes a C API (since Java JNI only interacts with
specific exported C functions). Dependency Walker doesn't show the
classes at all, and it doesn't tell you what language was used.

IOW, Dependency Walker is a useless tool for determining what language a
module was implemented with.

Tom

[Severian]

On Wed, 9 Feb 2005 14:07:44 +0330, "Herr Lucifer"
<"\n"HerrLucife r\n@microsoft.c om> wrote:

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API
functions. The thing I have noticed is that, 'almost' all system .dll and
.exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't
Microsoft used it in its operating system? Is there a compatibility issue
here that I am not aware of? Or something else?
---

IMHO:

For time-critical issues, smaller code size, better memory
consumption, improved control over efficiency, improved code
generation, simpler interface to assembler, and easier debugging
(especially the kernel and low-level code) the guts of Windows are
mostly written in C.

Additionally, much of the Windows (NT) kernel is based on VMS, which
was written in Bliss32 and VAX assembly, which were much easier to
implement as C.

Microsoft's C++ code (for the shell, directx, COM, etc.) are bizarre
and obfuscated anyway. Were Windows internals written in C++, I would
cry.

--
Sev

[Tom Widmer]

Severian wrote:

On Wed, 9 Feb 2005 14:07:44 +0330, "Herr Lucifer"
<"\n"HerrLucife r\n@microsoft.c om> wrote:

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API
functions. The thing I have noticed is that, 'almost' all system .dll and
.exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't
Microsoft used it in its operating system? Is there a compatibility issue
here that I am not aware of? Or something else?
---

IMHO:

For time-critical issues,

Do you mean that C is faster executing? Or that its performance is more
consistent (for a realtime system)? I don't think either statement is
particularly true, though some C and C++ features should be avoided in
code that should run in a bounded amount of time (e.g. no dynamic
allocation, no disk IO, etc.).

smaller code size, better memory consumption,
C does generally produce slightly smaller code, due to the overhead EH
and RTTI in C++. However, both of those may be avoided if desired.

improved control over efficiency,

How so?

improved code generation,
The code generation is generally worse in C, since I believe that type
based alias analysis isn't as good in C. Is there any other respect in
which you think C can generate better code?

simpler interface to assembler,

What do you mean?

and easier debugging (especially the kernel and low-level code)
But macros are far harder to debug than inline functions!

the guts of Windows are mostly written in C.

That I know nothing about, but it certainly sounds true. But I believe
much of the Linux kernel is now written in C++ (as was BeOS). C++ is
primarily a systems programming language - it was specifically designed
for writing OSes (among other things), hence the priniciple of "You
don't pay for what you don't use."

I'd definitely prefer to write an OS in C++ rather than C, and the
resulting OS would probably be faster and better for it (though possibly
not smaller).

Tom

[Severian]

On Thu, 10 Feb 2005 18:07:35 +0000, Tom Widmer
<to********@hot mail.com> wrote:

Severian wrote:

On Wed, 9 Feb 2005 14:07:44 +0330, "Herr Lucifer"
<"\n"HerrLucife r\n@microsoft.c om> wrote:

It is a long time now that I am using "Dependency Walker for Win32" and
navigating through different Dlls in "System32" folder to find my target API
functions. The thing I have noticed is that, 'almost' all system .dll and
.exe
files are written in C and not C++. If C++ is a powerful OO language and
it's much greater than C for large application development, then why haven't
Microsoft used it in its operating system? Is there a compatibility issue
here that I am not aware of? Or something else?
---

IMHO:

For time-critical issues,

Do you mean that C is faster executing? Or that its performance is more
consistent (for a realtime system)? I don't think either statement is
particularly true, though some C and C++ features should be avoided in
code that should run in a bounded amount of time (e.g. no dynamic
allocation, no disk IO, etc.).

Sorry, I wasn't trying to start a language war. I program in both C
and C++, and have seen plenty of good and bad examples of both. I was
comparing well-written C with well-written C++ (not simply C-like code
compiled by a C++ compiler).

But generally, when using the constructs that make C++ a great
language, it is very much simpler to estimate the overhead of C
statements vs. C++ statements. (I'm not talking about C code compiled
by a C++ compiler!)
smaller code size, better memory

consumption,
C does generally produce slightly smaller code, due to the overhead EH
and RTTI in C++. However, both of those may be avoided if desired.

In my experience, you have to know a lot more about C++ (and how it is
implemented on a particular platform) to make it as efficient (memory
and speed-wise) as well-written C.
improved control over efficiency,

How so?
Because, as examples, overloaded operators and virtual functions
introduce non-obvious overhead that is more explicit in C.
improved code

generation,
The code generation is generally worse in C, since I believe that type
based alias analysis isn't as good in C. Is there any other respect in
which you think C can generate better code?

You're probably right, in the general case of compiling simple C++
code; and in some cases (i.e., templates) even when generating complex
code. But once you start using the things that make C++ such a
wonderful language, the generated code tends, in my experience, to
become bloated and wasteful -- and much more difficult to debug.
simpler interface to assembler,

What do you mean?
I am speaking of calling assembly from C++ or vice versa, not inline
assembly, which is quite platform-specific.

One example: since assembly language has no concept of C++ objects,
you have to "deobjectif y" any data you want to access from assembler
(or C for that matter!), or know a lot about how a particular C++
compiler represents objects in memory and write extra assembly
language to work with them.
and easier debugging

(especially the kernel and low-level code)
But macros are far harder to debug than inline functions!

Most modern C compilers include inline functions, though by looking at
code generated by MS and GNU C++, macros are often much more
efficient, and thus often more appropriate for OS code.

The difficulty I was referring to was the semi-invisible things that
C++ does, that require you to know the implementation of classes you
use. Overloaded operators (-> and [] come immediately to mind) make
debugging a loathesome task unless you have access to the source code
for the original class. Even in those cases, it's often difficult to
figure out what exactly is going on behind the scenes.

I've seen well-written C++ code that is a joy to work with, but a lot
more of it is obfuscated (unintentionall y?) to the point of
hair-pulling. Most of Microsoft's C++ falls into the latter category!

When writing C++, I love STL and wish that MS had not tried to make
their own horrid messes first.
the guts of Windows are

mostly written in C.
That I know nothing about, but it certainly sounds true. But I believe
much of the Linux kernel is now written in C++ (as was BeOS). C++ is
primarily a systems programming language - it was specifically designed
for writing OSes (among other things), hence the priniciple of "You
don't pay for what you don't use."

I agree that well-written C++ code (in a _specific_ rather than
generic way) is very appropriate for operating systems, as long as
provisions are made for using the OS API from other languages.
I'd definitely prefer to write an OS in C++ rather than C, and the
resulting OS would probably be faster and better for it (though possibly
not smaller).

I think it boils down to whether the code is well-written or not; the
simpler basis of C makes it easier, in my opinion, to write efficient
and understandable code. That being said, I have worked with and
(hope) I have written efficient and easily maintainable C++ code as
well.

--
Sev