I've applied this patch to update c99status.html for the recent changes regarding extended identifiers. The remaining known C99/C11 conformance issues (beyond ordinary bugs) are all floating-point issues (mostly but not entirely Annex F/G).
Index: c99status.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/c99status.html,v retrieving revision 1.62 diff -u -r1.62 c99status.html --- c99status.html 27 Oct 2013 15:41:51 -0000 1.62 +++ c99status.html 6 Nov 2014 21:18:36 -0000 @@ -8,9 +8,9 @@ <h1>Status of C99 features in GCC</h1> <p>C99 is substantially completely supported as of GCC 4.5 -(with <code>-std=c99 -pedantic-errors</code> used), modulo bugs, -extended identifiers (supported except for corner cases -when <code>-fextended-identifiers</code> is used), and floating-point +(with <code>-std=c99 -pedantic-errors</code> used; +<code>-fextended-identifiers</code> also needed to enable extended +identifiers before GCC 5), modulo bugs and floating-point issues (mainly but not entirely relating to optional C99 features from Annexes F and G). The following table gives more details of the C99 support in different GCC versions.</p> @@ -30,7 +30,8 @@ if additional compiler features could be useful in conjunction with it. It is assumed that GCC is used with <code>-std=c99 -pedantic-errors</code> (for versions 3.0 and later), as well -as <code>-fextended-identifiers</code> in the case of that feature. +as <code>-fextended-identifiers</code> in the case of that feature +before GCC 5. Where library cooperation is required, it is assumed that a recent version of the GNU C Library is in use, and support with other C libraries may be less good. Where the version listed is before GCC @@ -138,8 +139,9 @@ <tr><td><em>extended identifiers</em></td> <td>GCC 4.1</td> - <td>Requires <code>-fextended-identifiers</code> and some corner - cases may be broken.</td> + <td>Some corner cases were fixed in GCC 5; + <code>-fextended-identifiers</code> was needed to enable this + feature before that version.</td> </tr> <tr><td><em>hexadecimal floating-point constants and -- Joseph S. Myers jos...@codesourcery.com