Static analyzer run

["Lorenz Minder" <lminder@gmx.net>]

Hi,

I've run PARI through a static source code analyzer to see if it finds
any bugs (and to see if the tool is worth anything).

It found a couple of minor things, such as duplicate assignments.  I
think the benefit of fixing those is mostly code readability.  Those
are in the attached minor_bugs.patch.

Then it uncovered a few real bugs. I (hope I) fixed those in
sa_bugfixes.patch.

All tests still run fine with those patches attached.

And then it gave a couple of messages I did not investigate closer,
but that look very suspicious.  I think it would probably be a
worthwhile time investment if some PARI guru looked into those.
See below.

Best,
--Lorenz

../src/basemath/base2.c:1637:16: warning: Dereference of null pointer
      S->phi = typ(opa) == t_INT? RgX_Rg_add_shallow(S->phi, opa)
               ^
../src/basemath/base2.c:2383:3: warning: Branch condition evaluates to an uninitialized value.
  if (den)
  ^   ~~~
../src/basemath/base3.c:1553:7: warning: Value stored to 'ex' is never read
      ex = EX;
      ^    ~~
../src/basemath/base3.c:1563:16: warning: Value stored to 'ex' is never read
        if (v) ex = mulii(ex, powiu(p, v));
               ^    ~~~~~~~~~~~~~~~~~~~~~~
../src/basemath/bibli1.c:2129:14: warning: Value stored to 'j' is never read
        for (j = 0; i <= s; i++)
             ^   ~
../src/basemath/polarit3.c:2257:36: warning: Dereference of null pointer
  if (av2) { avma = av2; *lambda = next_lambda(*lambda); }
                                   ^
../src/basemath/rootpol.c:2255:27: warning: Value stored to 'av2' is never read
      xd = RgX_deriv(xc); av2 = avma;
                          ^     ~~~~
../src/language/eval.c:625:11: warning: Dereference of null pointer
      if (typ(base)!=t_VEC) sbase = GSTR(base);
          ^
../src/modules/QX_factor.c:1147:63: warning: Pass-by-value argument in function call is undefined.
    if (DEBUGLEVEL>5) msgtimer("gcd mod %lu (bound 2^%ld)", p,expi(q));
                                                              ^    ~
../src/modules/QX_factor.c:1154:10: warning: Pass-by-value argument in function call is undefined.
    qp = muliu(q,p);
         ^     ~

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Attachment: minor_bugs.patch
Description: Binary data

Attachment: sa_bugfixes.patch
Description: Binary data