[Bug analyzer/94433] New: enhancement: 12 * constify some parameters

[Bug analyzer/94433] New: enhancement: 12 * constify some parameters

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

            Bug ID: 94433
           Summary: enhancement: 12 * constify some parameters
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: analyzer
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

>From today's run of cppcheck over the gcc trunk source code:

$ fgrep /analyzer/ cppcheck.20200401.out | fgrep constParameter
trunk.git/gcc/analyzer/diagnostic-manager.cc:289:49: style: Parameter 'v' can
be declared with const [constParameter]
trunk.git/gcc/analyzer/diagnostic-manager.cc:293:50: style: Parameter 'k1' can
be declared with const [constParameter]
trunk.git/gcc/analyzer/diagnostic-manager.cc:293:70: style: Parameter 'k2' can
be declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:414:49: style: Parameter 'k' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:420:50: style: Parameter 'k1' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:420:70: style: Parameter 'k2' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:484:49: style: Parameter 'k' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:490:50: style: Parameter 'k1' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:490:70: style: Parameter 'k2' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:551:49: style: Parameter 'k' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:557:50: style: Parameter 'k1' can be
declared with const [constParameter]
trunk.git/gcc/analyzer/exploded-graph.h:557:70: style: Parameter 'k2' can be
declared with const [constParameter]

Might be worth tidying up.

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks for filing this.  I've been attempting to reproduce this, but I'm not
getting any warnings out of cppcheck.

That said, looking at
  git show
a96f1c38a787fbc847cb014d4b094e2787d539a7:gcc/analyzer/diagnostic-manager.cc
(to get the version for the bug was filed) the first few warnings in comment #0
seem to be on class dedupe_hash_map_traits:

 289   │   static inline hashval_t hash (const key_type &v)
 291   │   {
 292   │     return v->hash ();
 293   │   }
 294   │   static inline bool equal_keys (const key_type &k1, const key_type
&k2)
 295   │   {
 296   │     return *k1 == *k2;
 297   │   }

where key_type is:
 286   │   typedef const dedupe_key *key_type;

and I don't think the above code has changed since then.

Is there a good way to invoke cppcheck on GCC?  I'm naively trying "cppcheck
gcc/analyzer" and passing in -I options, and am not getting any warnings.

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

--- Comment #2 from David Binderman <dcb314 at hotmail dot com> ---

I use something like

cppcheck --enable=all --language=c++ trunk.git/gcc/analyzer/*.{h,cc}

This seems to work to me, although my copy of cppcheck is a hand
tweeked version of their development code.

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-09-28
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1

--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks - with that I can reproduce the warnings from comment #0.

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |WAITING

--- Comment #4 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks again for your help with getting cppcheck running.  I found some issues
with cppcheck and committed these fixes:
  g:20d16d61dd22a9bfb66d5c4a383d193037e8f16d (unused field)
  g:c0ed6afef7897f32dc199da9a5430664fcbb61bb (missing "final override" on some
vfuncs)

However I'm confused by the "can be declared with const [constParameter]"
warnings in comment #0 - they look const to me.  What are these messages trying
to tell me, and how would I fix them?  (could they be false positives?)

Any ideas?

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to David Malcolm from comment #4)
> However I'm confused by the "can be declared with const [constParameter]"
> warnings in comment #0 - they look const to me.  What are these messages
> trying to tell me, and how would I fix them?  (could they be false
> positives?)
> 
> Any ideas?

If the tool is telling you they can be declared with const and they
are already const, then that looks like a false positive to me.

cppcheck isn't perfect.

I checked diagnostic-manager.cc and exploded-graph.h and I think
they are false positives.

[Bug analyzer/94433] enhancement: 12 * constify some parameters

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94433

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

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

--- Comment #6 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks.  I took another look through the output, and nothing struck me as
serious, so I'm going to close this one out.