https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102732
Bug ID: 102732
Summary: quadratic/exponential time complexity on D demangler
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: demangler
Assignee: unassigned at gcc dot gnu.org
Reporter: contact at lsferreira dot net
Target Milestone: ---
Feeding the initial mangled symbol
"_D3eeeRRRRS2RPRRS2RPRgRgRRRRRS4RPRgRggRgRRRRRS2RPRgPRRS6RPRgRgRRRS2RPRgPRRS2"
and subsequentially append "_D3eeeRRRRRRRRRS2RPRgPRRS6RPRgRgRRRS2RPRgPRRS2" to
it, makes the demangler demangle it in an excessive time.
This was found with libfuzzer, and other meaningful results can be found here:
https://lsferreira.net/public/assets/posts/d-saoc-2021-02/fuzzer-results/
This seems to be either quadratic or exponential in terms of time complexity.
Similar to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80002 , this needs to
be fixed until we add libiberty to Google OSS fuzz.
