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- <h1>Compiling and running the Main module</h1>
-
-GHC allows you to determine which module contains the "main" function, and
-what that function is called, via the <code>-fmain-is</code> flag. The trouble is
-that the runtime system is fixed, so what symbol should it link to?
-<p>
-The current solution is this. Suppose the main function is <code>Foo.run</code>.
-<ul>
-<li>
-Then, when compiling module <code>Foo</code>, GHC adds an extra definition:
-<pre>
- :Main.main = runIO Foo.run
-</pre>
-Now the RTS can invoke <code>:Main.main</code> to start the program. (This extra
-definition is inserted in TcRnDriver.checkMain.)
-<p><li>
-Before starting the program, though, the RTS also initialises the module tree
-by calling <code>init_:Main</code>, so when compiling the main module (Foo in this case),
-as well as generating <code>init_Foo</code> as usual, GHC also generates
-<pre>
- init_zcMain() { init_Foo; }
-</pre>
-This extra initialisation code is generated in CodeGen.mkModuleInit.
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