[Bug tree-optimization/90989] [9 Regression] incorrrect strlen result after second strcpy into the same destination

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90989

--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Fri Aug  2 16:57:19 2019
New Revision: 274021

URL: https://gcc.gnu.org/viewcvs?rev=274021&root=gcc&view=rev
Log:
Backport from mainline

PR tree-optimization/90989 - incorrrect strlen result after second strcpy
        into the same destination

gcc/ChangeLog:

        PR tree-optimization/90989
        * tree-ssa-strlen.c (handle_char_store): Constrain a single character
        optimization to just single character stores.

gcc/testsuite/ChangeLog:

        PR tree-optimization/90989
        * gcc.dg/strlenopt-26.c: Exit with test result status.
        * gcc.dg/strlenopt-67.c: New test.


Added:
    branches/gcc-9-branch/gcc/testsuite/gcc.dg/strlenopt-67.c
Modified:
    branches/gcc-9-branch/gcc/ChangeLog
    branches/gcc-9-branch/gcc/testsuite/ChangeLog
    branches/gcc-9-branch/gcc/testsuite/gcc.dg/strlenopt-26.c
    branches/gcc-9-branch/gcc/tree-ssa-strlen.c