It depends on what you want. If you want to install an old copy of Visual Studio from 20 years ago then you should be able to write a program and compile it and have that work on XP. But that comes with limitations. You're not going to be able to use even C++11 and will be stuck with C++03, or maybe even C++98. If that's acceptable to you then it can work. But if you want to compile something that somebody else wrote or want to use some library that somebody else wrote, it probably won't work in that environment.
Or you could install and old copy of Cygwin or MinGW.
Do you want to run a modern Visual Studio and target XP? Maybe you can make that work if you install an old platform SDK and set WINVER and _WIN32_VERSION and work around all the warnings and compatibility problems that you'll run into. It is fighting an uphill battle and it will continue to get worse with each new version of VS that you want use.
For rust there is Rust9x https://seri.tools/blog/announcing-rust9x/. But I think this is the effort of handful of people. It is behind the upstream rust and it could go away at any time. If you want to write a toy program in Rust then it is fine, but if you want something that's going to be supported long-term you're rolling the dice.
Python 3.4.4 is the last version of Python that will run on Windows XP. That's 10 years old and many things on PyPI now require newer versions of Python so you'd be stuck with old, unsupported versions of those modules, possibly containing security issues.
As far as I'm aware so long as you limit yourself to APIs that were available in XP you don't actually need an older SDK to develop for it with modern MSVC. The early windows platform layer stuff in the handmade hero series demonstrates doing so without anything like Cygwin or MinGW.
Most new APIs introduced since Vista are COM based, and after Windows 8, WinRT based (basically COM with IIinspectable, application identity, and .NET metadata instead of type libraries).
Plain old Win32 C API is basically frozen on Windows XP view of the world, although there are a couple of new .....ExNum() suffixes for stuff like HDPI or various IO improvements, the userspace drivers initially COM (UMDF), but reverted back to plain C struct with function pointers on version 2.0.
The only officially (at least partially) supported way from Microsoft is to add into Visual Studio the toolchain named "C++ Windows XP Support for VS 2017 (v141) tools". It is still there in the "individual components" of Visual Studio Installer for the latest VS but it is marked as [Deprecated]. It is a safe bet that MS will never fix any existing bugs in it or update it so at this point your best bet might be with the open source tools.
All other currently supported toolchains rely on runtimes that are explicitly not compatible with Win XP.
I feel like it is unfair to blame the compiler when you've explicitly asked for `/O1`. If you change this to `/O2` or `/Ox` then MSVC will optimize this into a constant 5, proving that it does "know" that strlen will return 5 in this case.
If you want to tell the compiler not to worry about the possible buffer overrun then you can try `int foo(char const s[static 4])`. Or use `&` instead of `&&` to ensure that there is no short-circuiting, e.g. `if ((s[0] == 'h') & (s[1] == 'e') & (s[2] == 'l') & (s[3] == 'l'))` Either way, this then compiles down to a single 32-bit comparison.
Interestingly, it is comparing against a different 32-bit value than `bar` does. I think this is because you accidentally got the order backwards in `bar`.
The code in `bar` is probably not a good idea on targets that don't like unaligned loads.
This was definitely NT. It was the IIS server at an ISP. It might have been the same timer, and it might’ve been 49 days instead of 42. Its was in the forties, and 42 sticks in my mind pretty easily. It may have been basically the same bug.
That, or the Reddit poster and I have the same wrong memory of the bug. I do know my boss at the time made us make the scheduled task to reboot because he understood it at the time to happen on NT 4.
My bad on that typo. I write "$@" so often in shell scripts that I should know better. Also would've been caught by shellcheck. Outside the hn edit window though, so my mistake is permanent :(
I tried to reproduce this binary to see what the 278 KB was being taken up by. The first obstacle that I ran into was that the build.bat file doesn't work if you have git configured to use core.autocrlf=false. Changing that to core.autocrlf=true and recloning was sufficient to get me building.
I'm using x86_64-15.1.0-release-win32-seh-msvcrt-rt_v12-rev0.7z from https://github.com/niXman/mingw-builds-binaries/releases/tag... as the toolchain. This produces a 102 KB .exe file. Right off the bat we are doing much better than the claimed 278 KB. Maybe the author is using a different toolchain or different settings? Exact steps to reproduce would be welcome.
We can improve this by passing some switches to GCC.
The v0.1 release from yesterday, at the time of posting, was 278 KB. The latest release, v0.3 from 9 hours ago, adds -Os -s and UPX to compress down to 27 KB.
I also used mingw and yet I arrived at different results. Maybe it was a different version, or a different distro of MinGW, or a 32-bit vs. 64-bit issue, or I'm linking against a different CRT. Without details from OP, we can't really tell.
It seems like it should be possible to factor out most of the iterator boilerplate into a helper class. Then each place where you want to iterate you can construct an instance of that helper class and supply a lambda that specifies how to descend into children. If you're doing the same iteration in several places then you can use a named function instead of a lambda, which means less typing for each `for` loop. Here's a rough sketch: https://godbolt.org/z/x94WY77rv
Or you could install and old copy of Cygwin or MinGW.
Do you want to run a modern Visual Studio and target XP? Maybe you can make that work if you install an old platform SDK and set WINVER and _WIN32_VERSION and work around all the warnings and compatibility problems that you'll run into. It is fighting an uphill battle and it will continue to get worse with each new version of VS that you want use.
For rust there is Rust9x https://seri.tools/blog/announcing-rust9x/. But I think this is the effort of handful of people. It is behind the upstream rust and it could go away at any time. If you want to write a toy program in Rust then it is fine, but if you want something that's going to be supported long-term you're rolling the dice.
Python 3.4.4 is the last version of Python that will run on Windows XP. That's 10 years old and many things on PyPI now require newer versions of Python so you'd be stuck with old, unsupported versions of those modules, possibly containing security issues.