[Bug c/50590] New: Initializing a variable to itself yields garbage/UB and no warning.

[eyal.lotem at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50590

             Bug #: 50590
           Summary: Initializing a variable to itself yields garbage/UB
                    and no warning.
    Classification: Unclassified
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: eyal.lo...@gmail.com


Exact version string:

gcc (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2

This is very similar to: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10538

But weirdly, while:

    int x = x + 1;

Does yield a warning, this:

    int x = x;

does not.

This may accidentally happen in e.g macros:

    #define F(_x) \
       int _x = x;
       ... use _x ...

expands to:

       int x = x;
       use x;