https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69759
Bug ID: 69759 Summary: __builtin_alloca undocumented Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: msebor at gcc dot gnu.org Target Milestone: --- Documentation for the __builtin_alloca intrinsic function appears to be missing from the manual: $ find /src/gcc/trunk/gcc/doc -type f | xargs grep builtin_alloca | wc -l 0 The builtin is relied on by GCC itself (e.g., libstdc++) as well as other projects (e.g., GLIBC), and is even mentioned on the Linux alloca() man page: http://man7.org/linux/man-pages/man3/alloca.3.html