quickjs is not compatible with ucrt of Windows SDK 26100

[twinstar6980]

The macro definition NAN is used in quickjs.c.
https://github.com/quickjs-ng/quickjs/blob/0c8aeb1d5093869479e914980ef5588020bce64a/quickjs.c#L40297

For Windows platform, NAN is defined in ucrt/corecrt_math.h.
In Windows SDK 22621:

#define NAN ((float)(INFINITY * 0.0F))

In this case, the compiler can complete the compilation, but Microsoft has made changes in Windows SDK 26100:

#define _UCRT_NAN (__ucrt_int_to_float(0x7FC00000))
#define NAN _UCRT_NAN

When using SDK 26100, the compiler (msvc-cl 19.41 or clang-cl 19.1) will report an error: C2099 initializer is not a constant.

Is there any way to solve this problem?

[695137400]

我最初也是用终端控制台编译，会报错，后来改用了clion，直接导入cmake项目就行，不报错，完美

[twinstar6980]

我最初也是用终端控制台编译，会报错，后来改用了clion，直接导入cmake项目就行，不报错，完美

你的clion用的是minggw还是msvc全家桶？能麻烦下在clion里看看NAN是怎么定义的么？

[twinstar6980]

I tested the value of NAN under different conditions:
/fp:precise（default）
(-)22621: fff8000000000000
(+)22621(_UCRT_NEGATIVE_NAN): 7ff8000000000000
(-)26100(_UCRT_NOISY_NAN): fff8000000000000
(+)26100(_UCRT_NOISY_NAN,_UCRT_NEGATIVE_NAN): 7ff8000000000000
(+)26100: 7ff8000000000000
(-)26100(_UCRT_NEGATIVE_NAN): fff8000000000000

Even if defined _UCRT_NOISY_NAN, NAN is also quiet (why not noisy/signaling?). If /fp:strict is enabled, 22621 and 26100(_UCRT_NOISY_NAN) will produce positive NAN values.

I don't know if the behavior of quickjs depends on the specific value of NAN. If not, should we add _UCRT_NOISY_NAN macro definition in cmake to be compatible with sdk26100?

[saghul]

Interesting! Do you know how to use that version in a GH Action so we can add a CI?

[twinstar6980]

Interesting! Do you know how to use that version in a GH Action so we can add a CI?

maybe you can use this repo: https://github.com/GuillaumeFalourd/setup-windows10-sdk-action

[saghul]

Looks like 26100 doesn't work though: (26100 returns an error)

[695137400]

[695137400]

[saghul]

Not sure what you're asking here.

[twinstar6980]

Looks like 26100 doesn't work though: (26100 returns an error)

Try this: https://github.com/marketplace/actions/windows-sdk-install
I did a simple test and it was able to install sdk26100 successfully.

[twinstar6980]

emm，我不太了解 mingw ，这个错误是因为最新版本 winsdk ucrt 更改后的 NAN 宏不再能作为编译期常量来使用。你用 mingw 工具链没触发这个问题应该是因为 mingw 内部自己实现了 NAN 的定义，而没有走 ucrt 的 NAN 定义。这与这个 issue 无关。

[bnoordhuis]

I don't know if the behavior of quickjs depends on the specific value of NAN

Yes. From libbf.c (handles BigInts):

quickjs/libbf.c

Lines 2463 to 2464 in 89883ae

	if (a->expn == BF_EXP_NAN) {
	u.u = 0x7ff8000000000000; /* quiet nan */

Changing JS_NAN also changes the output of JS_WriteObject, the serializer. That's not exactly fatal but it would be annoying to have two machines produce different output for the same input.

[twinstar6980]

The WinSDK version can be set in CI via:

  - name: Install windows sdk
    uses: ChristopheLav/windows-sdk-install@v1
    with:
    version-sdk: 26100
    features: 'OptionId.DesktopCPPx86,OptionId.DesktopCPPx64'

And specify -DCMAKE_SYSTEM_VERSION:STRING=10.0.26100.0 in the cmake command line.

.
Regarding specific values ​​for nan:
In winsdk 22621 and earlier, the NAN macro produces negative nan (unless /fp:strict is specified), which does not seem to be the value expected by libbf. However, quickjs-ng has always worked this way on windows before winsdk 26100.
Specifying _UCRT_NOISY_NAN will revert the behavior of nan to that before 22621. If you don't want to use it, it seems that you must refactor the relevant code to not rely on the "compile-time constant" feature.

[saghul]

I'll try to get back to this next week!