c - 什么是 C17 以及对语言进行了哪些更改？

Question

当我查看有关 GCC 8 的新闻时，我 saw他们添加了对 2017 版 C 语言(不是 C++17，实际上是 C17)的支持。但是我在 Internet 上找不到有关它的任何信息。

它是像 C11 这样的新 ISO 版本，还是只是 GCC 团队在其编译器中进行某些更正时使用的代号？

Answer 1

根据 GCC引用，C17 实际上是 C11 标准的错误修复版本，集成了 DR 解决方案。

C17, a bug-fix version of the C11 standard with DR [Defect Report] resolutions integrated, will soon go to ballot. This patch adds corresponding options -std=c17, -std=gnu17 (new default version, replacing -std=gnu11 as the default), -std=iso9899:2017. As a bug-fix version of the standard, there is no need for flag_isoc17 or any options for compatibility warnings; however, there is a new __STDC_VERSION__ value, so new cpplib languages CLK_GNUC17 and CLK_STDC17 are added to support using that new value with the new options. (If the standard ends up being published in 2018 and being known as C18, option aliases can be added. Note however that -std=iso9899:199409 corresponds to a __STDC_VERSION__ value rather than a publication date.)

(There are a couple of DR resolutions needing implementing in GCC, but that's independent of the new options.)

因此，C17 中没有包含任何新功能。

Cppreference (History of C)说:

Future development

C17 Next minor C language standard revision, will include all accepted C11 defect reports, but no new features.

更新:

• 2018: C17 (ISO/IEC 9899:2018) (ISO Store) (Final draft) Includes the deprecation of ATOMIC_VAR_INIT and the fixes to the following defect reports:

[DR 400], [DR 401], [DR 402], [DR 403], [DR 404], [DR 405], [DR 406], [DR 407], [DR 410], [DR 412], [DR 414], [DR 415], [DR 416], [DR 417], [DR 419], [DR 423], [DR 426], [DR 428], [DR 429], [DR 430], [DR 431], [DR 433], [DR 434], [DR 436], [DR 437], [DR 438], [DR 439], [DR 441], [DR 444], [DR 445], [DR 447], [DR 448], [DR 450], [DR 452], [DR 453], [DR 457], [DR 458], [DR 459], [DR 460], [DR 462], [DR 464], [DR 465], [DR 468], [DR 470], [DR 471], [DR 472], [DR 473], [DR 475], [DR 477], [DR 480], [DR 481], [DR 485], [DR 487], [DR 491]