[Bug tree-optimization/78450] strlen(s) return value can be assumed to be less than the size of s

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78450

--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Mon Dec 18 22:49:57 2017
New Revision: 255790

URL: https://gcc.gnu.org/viewcvs?rev=255790&root=gcc&view=rev
Log:
PR middle-end/83373 - False positive reported by -Wstringop-overflow
PR tree-optimization/78450 - strlen(s) return value can be assumed to be less
than the size of s

gcc/ChangeLog:

        PR middle-end/83373
        PR tree-optimization/78450
        * tree-ssa-strlen.c (maybe_set_strlen_range): New function.
        (handle_builtin_strlen): Call it.

gcc/testsuite/ChangeLog:

        PR middle-end/83373
        PR tree-optimization/78450
        * gcc.dg/pr83373.c: New test.
        * gcc.dg/strlenopt-36.c: New test.
        * gcc.dg/strlenopt-37.c: New test.


Added:
    trunk/gcc/testsuite/gcc.dg/pr83373.c
    trunk/gcc/testsuite/gcc.dg/strlenopt-36.c
    trunk/gcc/testsuite/gcc.dg/strlenopt-37.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-strlen.c