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# `patchable-function-entry`

The `-Z patchable-function-entry=total_nops,prefix_nops` or `-Z patchable-function-entry=total_nops` compiler flag enables nop padding of function entries with 'total_nops' nops, with an offset for the entry of the function at 'prefix_nops' nops. In the second form, 'prefix_nops' defaults to 0.

As an illustrative example, `-Z patchable-function-entry=3,2` would produce:

    nop
    nop
    function_label:
    nop
    //Actual function code begins here

This flag is used for hotpatching, especially in the Linux kernel. The flag arguments are modeled after the `-fpatchable-function-entry` flag as defined for both Clang and gcc and is intended to provide the same effect.