[Valgrind-users] detecting uninitialized values in debug builds

[Ben W. <ben...@co...>]

Hello,

I have seen cases where valgrind (memcheck) will report conditional jump or move based on uninitialized value, and when examining the relevant source code, I can see that the value or variable is indeed uninitialized.  However, I've also been told that the g++ compiler will initialize all stack objects to zero when compiling for debug (the -g option).  Yet, valgrind still detects the un-init condition.

Does anybody know how this works behind the scenes?  This is mainly a curiosity question, no need to research it.

Ben White
Diagnostics, Calibration, and Verification (DCV)
Cohu Inc.