https://issues.dlang.org/show_bug.cgi?id=13562

          Issue ID: 13562
           Summary: [Enh] add permute[=seed] command line argument to dmd
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: DMD
          Assignee: nobody@puremagic.com
          Reporter: bugzilla@digitalmars.com

Return-Oriented-Programming (ROP) is a common attack method that malware uses to exploit buffer overflows:

  http://en.wikipedia.org/wiki/Return-oriented_programming

It relies on code having predictable contents and being in predictable locations.

The compiler often makes potayto-potahto decisions when generating code. By optionally providing a random value to the compiler, it can use that to toss a coin for the decision, making the generated code slightly different - different enough to defeat many ROP attacks.

Perturbations can be:

    changing the stack layout of locals

    changing the order of register selection

    changing the scheduling order of instructions

    weights given to loop variables

    instruction selection

    etc.

Syntax:

    -perturb=seed    // use seed to guide the compiler's coin toss
    -perturb         // have the compiler generate its own seed, likely by
                     // using the clock. -v will cause this value to be printed
    default          // use a seed value of 0, causing the same behavior the
                     // compiler has now


Using this can also shake out compiler bugs by "fuzz" testing of different paths through the compiler. It can help isolate stack corruption code bugs by helping find a more reproducible test case.

This switch can be particularly useful for those who are willing to build their apps from source, so that their executable will be different from anybody else's built from the identical source.

It shouldn't be hard to implement.

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