Break OO privacy: Difference between revisions
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→{{header|Phix}}: added syntax colouring, marked p2js incompatible
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We can easily break that privacy mechanism via low-level routines with the required simulated/fake context,<br>
and at the same time be reasonably confident that no-one is ever going to manage to achieve that by accident.
<!--<lang Phix>(notonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (no class under p2js)</span>
<span style="color: #008080;">class</span> <span style="color: #000000;">test</span>
<span style="color: #008080;">private</span> <span style="color: #004080;">string</span> <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"this is a test"</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">show</span><span style="color: #0000FF;">()</span> <span style="color: #0000FF;">?</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">.</span><span style="color: #000000;">msg</span> <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">class</span>
<span style="color: #000000;">test</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">new</span><span style="color: #0000FF;">()</span>
<span style="color: #000000;">t</span><span style="color: #0000FF;">.</span><span style="color: #000000;">show</span><span style="color: #0000FF;">()</span>
--?t.msg -- illegal▼
<span style="color: #000080;font-style:italic;">--?t.msg
<span style="color: #008080;">include</span> <span style="color: #000000;">builtins</span><span style="color: #0000FF;">\</span><span style="color: #000000;">structs</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span> <span style="color: #008080;">as</span> <span style="color: #000000;">structs</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">ctx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">routine_id</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"test"</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- magic/context
--constant ctx = "test" -- also works▼
--constant ctx = "test
<span style="color: #0000FF;">?</span><span style="color: #000000;">structs</span><span style="color: #0000FF;">:</span><span style="color: #000000;">fetch_field</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"msg"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ctx</span><span style="color: #0000FF;">)&</span><span style="color: #008000;">" (with some magic)"</span>
<span style="color: #000000;">structs</span><span style="color: #0000FF;">:</span><span style="color: #000000;">store_field</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"msg"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"this breaks privacy"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ctx</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">t</span><span style="color: #0000FF;">.</span><span style="color: #000000;">show</span><span style="color: #0000FF;">()</span>
<!--</lang>-->
<small>(Obviously you could inline the ctx values rather than create a separate constant.)</small>
{{out}}
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