My current work on the D compiler lead me to the following test
case which I put through a unmodified version of dmd 2.069.2
import core.stdc.stdio;
struct UnusedStruct
{
int i = 3;
float f = 4.0f;
};
class UnusedClass
{
int i = 2;
float f = 5.0f;
};
void main(string[] args)
{
printf("Hello World!");
}
When compiling this on windows with dmd -m64 main.d -L/MAP
and then inspecting the map file I noticed that the following 4
data symbols end up in the final executable although they
shouldn't be used.
0003:00000a90 _D4main12UnusedStruct6__initZ
0000000140046a90 main.obj
0003:00000ad0 _D4main11UnusedClass6__initZ
0000000140046ad0 main.obj
0003:00000af0 _D4main11UnusedClass7__ClassZ
0000000140046af0 main.obj
0003:00000ba0 _D4main11UnusedClass6__vtblZ
0000000140046ba0 main.obj
For the struct this is the initializer, for the class its the
initializer, class info and vtbl.
Is this behavior correct? Shouldn't UnusedStruct and UnusedClass
be stripped completely from the binary? Is this somehow connected
to the module info / object.factory?
I noticed by looking at some object file dumps that dmd puts each
function into its own section, but data symbols, like
initializers, are all merged into the same section. Could this be
the root issue?
