Yes, but the compiler is not usually creating the code that goes before main as part of building the application itself. It is, rather, a part of the C library, which may not even be part of the compiler distribution (for example gcc doesn't normally come with glibc, but it does link to glibc).Originally Posted by cpjust
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Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
In that case, I guess the compiler could create its own main() with the initialization stuff, then call the real main() (renaming it first of course).
"I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008
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It could. But what gcc does is call __main() inside main, because that solves the same problem - and saves renaming main and potentially causing problems because of collisions with the renamed main.
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Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Some runtime environments may not support it. Rather than restrict C++'s applicability to runtimes where this kind of initialization is possible, the standard writers left it open-ended by specifying that main() itself could contain global initialization code. On some platforms there might not be anywhere else to put it.
Code://try //{ if (a) do { f( b); } while(1); else do { f(!b); } while(1); //}
Wait.. really? Can you give an example of a platform that is unable to use a different entry point to perform initialization and then call main()?
For example, Visual C++ uses the entry point mainCRTStartup from their runtime library as the actual entry point, and mainCRTStartup calls main (or wmain). I don't see how something like this wouldn't be possible on every platform...
Or why couldn't a compiler behave as if an implicitly defined entry point existed in the code? For example:
Code:int __real_entry_point() { // determine commandline parameters // do initialization stuff // etc... return main(argc, argv); }
