.ctors :
{
/* gcc uses crtbegin.o to find the start of
the constructors, so we make sure it is
first. Because this is a wildcard, it
doesn't matter if the user does not
actually link against crtbegin.o; the
linker won't look for a file to match a
wildcard. The wildcard also means that it
doesn't matter which directory crtbegin.o
is in. */
/* KEEP (*crtbegin.o(.ctors))*/
/* We don't want to include the .ctor section from
from the crtend.o file until after the sorted ctors.
The .ctor section from the crtend file contains the
end of ctors marker and it must be last */
/* KEEP (*(EXCLUDE_FILE (*crtend.o ) .ctors))*/
/* KEEP (*(SORT(.ctors.*)))*/
KEEP (*(.ctors))
KEEP (*(.ctor))
}
//给C++的构造函数使用的section