SImple C++ code to D

[bearophile via Digitalmars-d-learn]

Alexandre:

> 	WORD e_res[4];

In D it's better to write:

     WORD[4] e_res;


> char image[0x800];

Note this is a thread-local variable. If you need a module-local 
variable you have to write:

__gshared char[0x800] image;


> void main(string[] args)

If you don't need the args, then write:

void main()

In D we usually indent using 4 spaces.


> 	auto dosh = cast(IMAGE_DOS_HEADER*)&image[0];

Perhaps better (untested):

     auto dosh = cast(IMAGE_DOS_HEADER*)image.ptr;



> 	dosh.e_magic = cast(WORD*)("MZ");

Try (assuming word is 2 bytes long):

dosh.e_magic = cast(WORD*)"MZ".ptr;



> 	auto stub = [0xb8, 0x01, 0x4c, 0xcd, 0x21];

Try to use:

immutable ubyte[5] stub = [0xb8, 0x01, 0x4c, 0xcd, 0x21];



> 	dmemcpy(&image[0x40], stub, stub.sizeof);
> }
>
> void * dmemcpy ( void * destination, const void * source, 
> size_t num ) pure nothrow
> {
> 	(cast(ubyte*)destination)[0 ..
> 		num][]=(cast(const(ubyte)*)source)[0 .. num];
> 	return destination;
> }

In D most cases you can avoid to use "void" as argument type.
Also try to minimize the use of casts.
And in D the "*" of pointers is written on the left, so you write 
"int* p" and not "int *p".
Also in that function you don't mutate "num", so put a "in" 
before "size_t".


> But I got errors in this:
> dmemcpy(&image[0x40], stub, stub.sizeof);

What errors?

Your code with some changes, but more improvements are possible 
(untested):


import std.stdio;
import core.stdc.string;
import std.c.windows.windows;

struct IMAGE_DOS_HEADER {
     WORD e_magic,
          e_cblp,
          e_cp,
          e_crlc,
          e_cparhdr,
          e_minalloc,
          e_maxalloc,
          e_ss,
          e_sp,
          e_csum,
          e_ip,
          e_cs,
          e_lfarlc,
          e_ovno;
     WORD[4] e_res;
     WORD e_oemid;
     WORD e_oeminfo;
     WORD[10] e_res2;
     LONG e_lfanew;
}

alias PIMAGE_DOS_HEADER = IMAGE_DOS_HEADER*;

__gshared char[0x800] image;

void main() {
     auto dosh = cast(IMAGE_DOS_HEADER*)image.ptr;
     dosh.e_magic = cast(WORD)*"MZ".ptr;

     immutable stub = x"b8 01 4c cd 21";
     memcpy(&image[IMAGE_DOS_HEADER.sizeof], stub.ptr, 
stub.length);
}


Bye,
bearophile