Re: How to get the body of a function/asm statement in hexadecimal
On 1/29/23 14:19, max haughton wrote: > it is not trivial to find where the *end* of a > function is I suspected as much and did run ... > objdump ... to fool myself into thinking that 0xc3 was . Well, arguments e.g. pointer values can have 0xc3 bytes in them. So, yes, I am fooled! :) Ali
Re: How to get the body of a function/asm statement in hexadecimal
On Sunday, 29 January 2023 at 21:45:11 UTC, Ruby the Roobster
wrote:
I'm trying to do something like
```d
void main()
{
auto d =
*d.writeln;
}
void c()
{
}
```
In an attempt to get the hexadecimal representation of the
machine code of a function. Of course, function pointers
cannot be dereferenced. What do?
Furthermore, I would like to be able to do the same for an
`asm` statement.
The function pointer can be casted to a pointer type. It is worth
saying, however, that it is not trivial to find where the *end*
of a function is. In X86 it's not even trivial to find the end of
an instruction!
If you'd just like the bytes for inspection, you could use a tool
like objdump. For more complicated situations you will need to
use a hack to tell you where the end of a function is.
Re: How to get the body of a function/asm statement in hexadecimal
On 1/29/23 13:45, Ruby the Roobster wrote:
> Of course, function pointers cannot be dereferenced.
Since you want to see the bytes, just cast it to ubyte*. The following
function dumps its own bytes:
import std;
void main() {
enum end = 0xc3;
for (auto p = cast(ubyte*)&_Dmain; true; ++p) {
writefln!" %02x"(*p);
if (*p == end) {
break;
}
}
}
(It can be written more elegantly as a range expression.)
> Furthermore, I would like to be able to do the same for an `asm`
statement.
I don't know how to get the address of asm blocks.
Ali
How to get the body of a function/asm statement in hexadecimal
I'm trying to do something like
```d
void main()
{
auto d =
*d.writeln;
}
void c()
{
}
```
In an attempt to get the hexadecimal representation of the
machine code of a function. Of course, function pointers cannot
be dereferenced. What do?
Furthermore, I would like to be able to do the same for an `asm`
statement.
