• Shriramana Sharma via Digitalmars-d (5/5) Jul 22 2015 Once the front end of DMD becomes fully D, I read that the backend
• cym13 (11/14) Jul 22 2015 I don't see an issue there. A compiler is a program that
• Xinok (6/9) Jul 22 2015 The Rust compiler is written in Rust but uses LLVM as a backend,
• rsw0x (2/11) Jul 22 2015 Both gcc and llvm expose a C api afaik
• Daniel =?UTF-8?B?S296w6Fr?= (3/7) Jul 22 2015 They will use same dmd frontend written in D.
• Kai Nacke (24/27) Jul 22 2015 Hi Shriramana!
• rsw0x (4/7) Jul 22 2015 I have a feeling this is going to end up being an issue.

Shriramana Sharma via Digitalmars-d <digitalmars-d puremagic.com> writes:

Once the front end of DMD becomes fully D, I read that the backend
will also become D, but then what will happen to GDC and LDC whose
backends are C++ IIUC?

-- 
Shriramana Sharma ஶ்ரீரமணஶர்மா
श्रीरमणशर्मा

"cym13" <cpicard openmailbox.org> writes:

On Wednesday, 22 July 2015 at 11:42:24 UTC, Shriramana Sharma 
wrote:
 Once the front end of DMD becomes fully D, I read that the 
 backend will also become D, but then what will happen to GDC 
 and LDC whose backends are C++ IIUC?

I don't see an issue there. A compiler is a program that 
implements a standard, as long as it generates good asm it could 
be written in brainfuck there would be no reason to care.

A D compiler written in D is a symbol, and D was written so that 
D-programmers could stop writting so much C++ so the idea of a 
DMD written in D is appealing, but that doesn't mean that all D 
compilers have to be written in D.

The only question is "Do they copy DMD correctly?". There is no 
doubt that it is doable in C++.

"Xinok" <xinok live.com> writes:

On Wednesday, 22 July 2015 at 11:42:24 UTC, Shriramana Sharma 
wrote:
 Once the front end of DMD becomes fully D, I read that the 
 backend will also become D, but then what will happen to GDC 
 and LDC whose backends are C++ IIUC?

The Rust compiler is written in Rust but uses LLVM as a backend, 
like LDC. I don't know the complexities of linking a D frontend 
with a C++ backend, but if the Rust team can do it, I'm sure that 
means GDC and LDC will continue to live on.

"rsw0x" <anonymous anonymous.com> writes:

On Wednesday, 22 July 2015 at 12:02:50 UTC, Xinok wrote:
 On Wednesday, 22 July 2015 at 11:42:24 UTC, Shriramana Sharma 
 wrote:
 Once the front end of DMD becomes fully D, I read that the 
 backend will also become D, but then what will happen to GDC 
 and LDC whose backends are C++ IIUC?

 The Rust compiler is written in Rust but uses LLVM as a 
 backend, like LDC. I don't know the complexities of linking a D 
 frontend with a C++ backend, but if the Rust team can do it, 
 I'm sure that means GDC and LDC will continue to live on.

Both gcc and llvm expose a C api afaik

Daniel =?UTF-8?B?S296w6Fr?= <kozzi dlang.cz> writes:

On Wed, 22 Jul 2015 17:12:14 +0530
Shriramana Sharma via Digitalmars-d <digitalmars-d puremagic.com> wrote:

 Once the front end of DMD becomes fully D, I read that the backend
 will also become D, but then what will happen to GDC and LDC whose
 backends are C++ IIUC?
 

They will use same dmd frontend written in D.

"Kai Nacke" <kai redstar.de> writes:

On Wednesday, 22 July 2015 at 11:42:24 UTC, Shriramana Sharma 
wrote:
 Once the front end of DMD becomes fully D, I read that the 
 backend will also become D, but then what will happen to GDC 
 and LDC whose backends are C++ IIUC?

Hi Shriramana!

My current *plan A* for LDC is:

Prerequisite: Enable LLVM Cpp backend
For release: Compile DDMD frontend to C++ and distribute D and 
C++ version of DDMD.
Bootstrap process:
- Create stage1 ldc compiler from C++ version of frontend.
- Use stage1 ldc to compile stage2 ldc compiler from D version of 
frontend.
- For verification it could be useful to create a stage3 ldc 
compiler using the stage2 compiler.

Advantage is that you only need a C/C++ compiler for bootstrap. 
Drawback is compile time.

I have not yet tested this approach. Therefore *plan B*:

Use a previous version of LDC to compile the current version. 
This will work as long as the used language in the frontend is 
stable.

The non-frontend parts of LDC might slowly migrate from C++ to D. 
The pain point here is that LDC makes use of the LLVM C++ API 
which is really superior to the C API.

Regards,
Kai

"rsw0x" <anonymous anonymous.com> writes:

On Wednesday, 22 July 2015 at 15:11:58 UTC, Kai Nacke wrote:
 Use a previous version of LDC to compile the current version. 
 This will work as long as the used language in the frontend is 
 stable.

I have a feeling this is going to end up being an issue.
Whatever D version ddmd is shipped with is going to need to be a 
LTS version.