Line

#line controls the line number and filename reported by the compiler when outputting warnings and errors.

void Test()
{
    #line 42 "Answer"
    #line filename "SomeFile.cs"
    int life; // compiler warning CS0168 in "SomeFile.cs" at Line 42
    #line default
    // compiler warnings reset to default
}

Pragma Checksum

#pragma checksum allows the specification of a specific checksum for a generated program database (PDB) for debugging.