[Bug tree-optimization/86636] [9 Regression] ICE in json::string::string

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86636

--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Author: dmalcolm
Date: Tue Jul 24 16:06:58 2018
New Revision: 262950

URL: https://gcc.gnu.org/viewcvs?rev=262950&root=gcc&view=rev
Log:
Fix segfault in -fsave-optimization-record (PR tree-optimization/86636)

There are various ways that it's possible for a gimple statement to
have an UNKNOWN_LOCATION, and for that UNKNOWN_LOCATION to be wrapped
in an ad-hoc location to capture inlining information.

For such a location, LOCATION_FILE (loc) is NULL.

Various places in -fsave-optimization-record were checking for
  loc != UNKNOWN_LOCATION
and were passing LOCATION_FILE (loc) to code that assumed a non-NULL
filename, thus leading to segfaults for the above cases.

This patch updates the tests to use
  LOCATION_LOCUS (loc) != UNKNOWN_LOCATION
instead, to look through ad-hoc location wrappers, fixing the segfaults.

It also adds various assertions to the affected code.

gcc/ChangeLog:
        PR tree-optimization/86636
        * json.cc (json::object::set): Fix comment.  Add assertions.
        (json::array::append): Move here from json.h.  Add comment and an
        assertion.
        (json::string::string): Likewise.
        * json.h (json::array::append): Move to json.cc.
        (json::string::string): Likewise.
        * optinfo-emit-json.cc
        (optrecord_json_writer::impl_location_to_json): Assert that we
        aren't attempting to write out UNKNOWN_LOCATION, or an ad-hoc
        wrapper around it.  Expand the location once, rather than three
        times.
        (optrecord_json_writer::inlining_chain_to_json): Fix the check for
        UNKNOWN_LOCATION, to use LOCATION_LOCUS to look through ad-hoc
        wrappers.
        (optrecord_json_writer::optinfo_to_json): Likewise, in four
        places.  Fix some overlong lines.

gcc/testsuite/ChangeLog:
        PR tree-optimization/86636
        * gcc.c-torture/compile/pr86636.c: New test.


Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr86636.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/json.cc
    trunk/gcc/json.h
    trunk/gcc/optinfo-emit-json.cc
    trunk/gcc/testsuite/ChangeLog