(Homepage) Unclear nature/contents (runtime or development environment?)

[Chealer]

I discovered MinGW-w64 5 days ago and still do not understand well what it is, but my understanding is now decent enough to say it is complicated.

The website helps to understand, but I also find that the homepage is confusing. I apologize if this ticket discusses several issues, but in particular, it is confusing what MinGW-w64 provides/contains. According to the image at the top, it is:

A complete runtime environment for GCC & LLVM for 32-bit (x86), 64-bit (x64), and ARM64 Windows

LIU Hao’s comment implicitly supports that, noting that MinGW-w64 includes a -crt package.

Yet according to the first paragraph:

Mingw-w64 is a collection of header files, import libraries, libraries and tools that, when combined with a compiler toolchain, such as GCC or LLVM, provides a complete development environment for building native Windows applications and libraries.

As a first step, it would greatly help for the homepage to make it clear whether MinGW-w64:

1. includes a CRT
2. is a runtime environment, part of a development environment, or both.

My understanding is that MinGW-w64 is at least part of a development environment.

License

[lhmouse]

mingw-w64 includes Windows headers, C runtime (CRT) and its headers, and some additional tools.

It's not a complete environment, for example, mingw-w64 doesn't provide a POSIX shell which is essential for building GCC. Usually you cross-compile mingw-w64 from Linux using a Linux shell, or do a native build on Windows using a Cygwin/MSYS2 shell.

[Chealer]

Thank you Hao

In that case, my understanding is that MinGW-w64 is both a development environment and a runtime environment. However, I am still struggling to define MinGW-w64. I wonder if it should be conceived as a product or as a project. If users do not typically install/use all components of MinGW-w64, perhaps it should be defined as a project, comparable to VideoLAN.

I think it would help going forward to start by defining what the CRT provides (when is the runtime environment useful?).

[lhmouse]

The CRT provides mainCRTStartup() for example, as well as many complementary functions since MSVCRT lacks them, linked statically; and in order to compile C code you need to include headers such as <stddef.h>; and in order to call Windows APIs you need Windows headers such as <winuser.h> and import libraries such as libkernel32.a.

[Chealer]

Ah, so if I understand correctly, the relevant parts of the CRT are all statically compiled in each program which needs them, when such a program is compiled using MinGW-w64? So users cannot tell that they are using the MinGW-w64 CRT?

[lhmouse]

Ah, so if I understand correctly, the relevant parts of the CRT are all statically compiled in each program which needs them, when such a program is compiled using MinGW-w64? So users cannot tell that they are using the MinGW-w64 CRT?

I am not sure what you are asking here. mingw-w64 CRT itself is not a complete CRT; it's a bridge, linked statically, between user code and one of the Microsoft CRT DLLs (MSVCRT, MSVCR{80,90,100,110,120}, or UCRTBASE).

This means that _DLL is always defined; unlike MSVC, there's no pure static CRT library to link against.

mingw-w64 also provides replacements for some functions, for example printf() supports GNU format specifiers which are not supported by Microsoft CRT. These functions are also linked statically.

[Chealer]

Thank you very much again Hao

Based on my new understanding, I recommend:

1. Removing the description as “A complete runtime environment for GCC & LLVM”
2. Adding a description of the MinGW-w64 CRT to the homepage
3. Moving the second paragraph down (perhaps in a section titled “Comparison to and relation with MinGW”), so that all content which defines MinGW-w64 is together.
4. Rephrasing the first paragraph to something like:

   MinGW-w64 is a collection of libraries, library declarations and macros (header files), a partial C runtime environment and tools that help target Windows when developing and building applications and libraries written in compiled languages such as C, C++ and Fortran. A toolchain, typically including GCC or LLVM, can be combined with MinGW-w64 to compile natively for Windows.

[lhmouse]

'A partial C runtime environment'...

No I don't think this is correct. As said above, mingw-w64 CRT does not fully provide the C library, but the other part, MSVCRT.DLL, has been pre-installed since Windows 98, and UCRT has been pre-installed since Windows 10. (Although it is still possible to link against MSVCR120.DLL for example, which would require users to install corresponding MSVC redistributable packages.)

So for example, GCC can be linked against mingw-w64 CRT, and then it must also be linked against MSVCRT.DLL or UCRTBASE.DLL; but either is a pre-installed system DLL, so no other libraries are required.

[Chealer]

Thank you Hao,

I am not sure what you think is incorrect, but by "partial", I meant "part of" (a C runtime environment).

But I do not know MinGW-w64 well, so my suggestion should definitely be reviewed by people who do. But the 4 recommendations do not need to be applied simultaneously. Someone doing #2 would facilitate doing #4 after.