[Python-Dev] Compiler warnings (original) (raw)

Giovanni Bajo rasky at develer.com
Wed Feb 1 20:40:58 CET 2006

Tim Peters <tim.peters at gmail.com> wrote:

[Thomas Wouters]

I noticed a few compiler warnings, when I compile Python on my amd64 with gcc 4.0.3:

Objects/longobject.c: In function 'PyLongAsDouble': Objects/longobject.c:655: warning: 'e' may be used uninitialized in this function Well, that's pretty bizarre. There's obviously no way to get to a reference to e without going through x = PyLongAsScaledDouble(vv, &e); first. That isn't a useful warning.

This has been discussed many times on the GCC mailing list. Ultimately, detecting whether a variable is using initialized or not (given full interprocedural and whole-program compilation) is a problem that can be reduced to the halting problem. The only thing that GCC should (and will) do is finding a way to be consistent across different releases and optimization levels, and to produce an useful number of warnings, while not issuing too many false positives.

Giovanni Bajo

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