{"id":5363,"date":"2007-11-06T01:44:00","date_gmt":"2007-11-06T01:44:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vcblog\/2007\/11\/06\/iso-c-standard-update\/"},"modified":"2019-02-18T18:54:18","modified_gmt":"2019-02-18T18:54:18","slug":"iso-c-standard-update","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/cppblog\/iso-c-standard-update\/","title":{"rendered":"ISO C Standard Update"},"content":{"rendered":"

Hello!  <\/span>My name is Arjun Bijanki, and I’m the test lead for the Visual C++ compiler.  <\/span>I’m also Microsoft’s representative on the <\/font>ISO C standard committee<\/font><\/a>.  <\/span>I recently returned from one of the committee’s semiannual meetings (this one was in Kona, Hawaii – tough trip! <\/font>J<\/span><\/span>)<\/font><\/font><\/p>\n

These days, the committee is thinking hard about the next revision to the C standard (unofficially termed C1x, where 0<=x<=9).  <\/span>At the meeting, the group discussed the <\/font>charter<\/font><\/a> for the next revision.  <\/span>For C users, the whole document is interesting reading, but I wanted to draw your attention to the Additional Principles for C1x:<\/font><\/p>\n

12. Trust the programmer<\/i>, as a goal, is outdated in respect to the security and safety<\/font><\/p>\n

programming communities. While it should not be totally disregarded as a facet of the<\/font><\/p>\n

spirit of C, the C1Xversion of the C Standard should take into account that programmers<\/font><\/p>\n

need the ability to check their work.<\/font><\/p>\n

\n

 <\/font><\/p>\n<\/p>\n

13. Unlike for C9X, the consensus at the London meeting was that there should be no<\/font><\/p>\n

invention, without exception. Only those features that have a history and are in common<\/font><\/p>\n

use by a commercial implementation should be considered. Also there must be care to<\/font><\/p>\n

standardize these features in a way that would make the Standard and the commercial<\/font><\/p>\n

implementation compatible.<\/font><\/p>\n

\n

 <\/font><\/p>\n<\/p>\n

14. Migration of an existing code base is an issue. The ability to mix and match C89,<\/font><\/p>\n

C99, and C1X based code is a feature that should be considered for each proposal.<\/font><\/p>\n

Migration is definitely important – I’d even call it a basic requirement — but I find the other two principles more interesting.  <\/span>#12 reflects the industry’s increased focus on security over the last 10 years, and it’s great to see the committee embracing that.  <\/span>It’s not surprising, given the committee’s work on <\/font>TR 24731<\/font><\/a> (Bounds-checking Interfaces, which includes most of the _s functions available in VS 2005).  <\/span><\/font><\/font><\/p>\n

The committee has also asked compiler vendors to present their most widely used language extensions for consideration.  <\/span>Features like <\/font>extended attributes<\/font><\/a>, and <\/font>thread local storage<\/font><\/a>, which are shared by multiple implementations (e.g. Visual C++ and GCC) will receive special attention.  <\/span>In many cases, implementations will differ on syntax, but the underlying concepts will be similar.  <\/span>As principle #13 says, the committee will strive to maintain compatibility.<\/font><\/p>\n

Now, the Visual C++ compiler team receives the occasionally question as to why we haven’t implemented C99.  <\/span>It’s really based on interest from our users.  <\/span>Where we’ve received many requests for certain C99 features, we’ve tried to implement them (or analogues).  <\/span>A couple examples are variadic macros, long long, __pragma, __FUNCTION__, and __restrict.  <\/span>If there are other C99 features that you’d find useful in your work, let us know!  <\/span>We don’t hear much from our C users, so speak up and make yourselves heard <\/font>J<\/span><\/span><\/font><\/p>\n

I should have another update from the C committee for you after the next meeting in April.<\/font><\/p>\n

Until next time,<\/font><\/p>\n

Arjun<\/font><\/p><\/p>\n","protected":false},"excerpt":{"rendered":"

Hello!  My name is Arjun Bijanki, and I’m the test lead for the Visual C++ compiler.  I’m also Microsoft’s representative on the ISO C standard committee.  I recently returned from one of the committee’s semiannual meetings (this one was in Kona, Hawaii – tough trip! J) These days, the committee is thinking hard about the […]<\/p>\n","protected":false},"author":289,"featured_media":35994,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-5363","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cplusplus"],"acf":[],"blog_post_summary":"

Hello!  My name is Arjun Bijanki, and I’m the test lead for the Visual C++ compiler.  I’m also Microsoft’s representative on the ISO C standard committee.  I recently returned from one of the committee’s semiannual meetings (this one was in Kona, Hawaii – tough trip! J) These days, the committee is thinking hard about the […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/posts\/5363","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/users\/289"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/comments?post=5363"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/posts\/5363\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/media\/35994"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/media?parent=5363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/categories?post=5363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/cppblog\/wp-json\/wp\/v2\/tags?post=5363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}