[LLVMdev] A small doubt

[Chris Lattner]

On Mon, 27 Oct 2003, Brian R. Gaeke wrote:

> __main is used primarily to call static constructors. The way you
> satisfy this dependency is to link the bytecode file against crtend.o
> (aka libcrtend.bc).  This is normally accomplished by using gccld
> (or by llvm-gcc <bytecode files> -o program, which calls gccld).

Brian is absolutely right.  Note that static constructors really only
happen in C++ programs (or C programs which use the GCC
constructor/destructor extensions, which are really really rare).
However, gccld should elimination all of the overhead of the __main
function if the functionality is not used, so C programs don't suffer any
overhead, and you can just delete the call to __main if it is causing you
grief.

If you're interested, the source code for __main lives in:
llvm/runtime/GCCLibraries/crtend/crtend.c & listend.ll

-Chris

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