[Bug analyzer/105888] New: RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[Bug analyzer/105888] New: RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105888

            Bug ID: 105888
           Summary: RFE: -fanalyzer should complain when an on-stack
                    address escapes/outlives the function
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: analyzer
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: dmalcolm at gcc dot gnu.org
            Blocks: 105887
  Target Milestone: ---

Implemented by Clang here:
  https://clang.llvm.org/docs/analyzer/checkers.html#core-stackaddressescape-c

Seems useful and fairly easy to implement.  The analyzer already has
  -Wanalyzer-use-of-pointer-in-stale-stack-frame
but we might as well detect stack addresses escaping.  Currently
region_model::pop_frame has:
  unbind_region_and_descendents (frame_reg,POISON_KIND_POPPED_STACK);
which updates anything pointing to frame_reg or within, so that could
be adapted to make a new warning.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105887
[Bug 105887] RFE: clang analyzer warnings that GCC's -fanalyzer could implement

[Bug analyzer/105888] RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105888

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
See also CWE-562: Return of Stack Variable Address
  https://cwe.mitre.org/data/definitions/562.html

[Bug analyzer/105888] RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[tlange at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105888

Tim Lange <tlange at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tlange at gcc dot gnu.org

--- Comment #2 from Tim Lange <tlange at gcc dot gnu.org> ---
I do have a fast prototype of this feature, but polishing that would require
PR105888 first. I plan to work on other checkers and get more familiar with the
code first, and then tackling PR105888 and hence this PR.

[Bug analyzer/105888] RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[tlange at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105888

--- Comment #3 from Tim Lange <tlange at gcc dot gnu.org> ---
(In reply to Tim Lange from comment #2)
> I do have a fast prototype of this feature, but polishing that would require
> PR105888 first. I plan to work on other checkers and get more familiar with
> the code first, and then tackling PR105888 and hence this PR.

I obviously meant PR106203 :)

[Bug analyzer/105888] RFE: -fanalyzer should complain when an on-stack address escapes/outlives the function

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105888
Bug 105888 depends on bug 106203, which changed state.

Bug 106203 Summary: Allow to emit diagnostics at return edges for the exit point as well as the call site
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106203

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED