• Sergey (15/15) Oct 13 2023 Based on experience on Debian
• kinke (9/21) Oct 13 2023 It's not required for the official prebuilt packages, as they
• whileclove (9/24) Nov 29 2023 The issue mentioned in the Debian Bug report you provided

Sergey <kornburn yandex.ru> writes:

Based on experience on Debian 
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960157) Docker 
image I found I was required to use 
"-flto-binary=/usr/lib/LLVMgold.so" in addition to "-flto=full".

Is it Debian specific issue or required for other distributions 
as well?

For example on Archlinux the liblphobos package provides two 
files:
- usr/lib/libdruntime-ldc-lto.a
- usr/lib/libphobos2-ldc-lto.a

So probably adding "-defaultlib=phobos2-ldc-lto,druntime-ldc-lto" 
will be fine.

But is "-flto-binary" is still required? What is it used for?

Can we please improve some information about proper flags usage 
for LTO enabled code in LDC?

kinke <noone nowhere.com> writes:

On Friday, 13 October 2023 at 09:37:49 UTC, Sergey wrote:
 Based on experience on Debian 
 (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960157) 
 Docker image I found I was required to use 
 "-flto-binary=/usr/lib/LLVMgold.so" in addition to "-flto=full".

 Is it Debian specific issue or required for other distributions 
 as well?

It's not required for the official prebuilt packages, as they 
bundle the plugin directly. `/usr/lib/LLVMgold.so` is in the 
default search path, so should be found automatically, unless 
Debian have patched this: 
https://github.com/ldc-developers/ldc/blob/60e45d619a00e32f79976c9e0047a7828d47c1ea/driver/linker-gcc.cpp#L114

 For example on Archlinux the liblphobos package provides two 
 files:
 - usr/lib/libdruntime-ldc-lto.a
 - usr/lib/libphobos2-ldc-lto.a

 So probably adding 
 "-defaultlib=phobos2-ldc-lto,druntime-ldc-lto" will be fine.

This is a separate thing, to be used explicitly when wanting to 
LTO druntime and Phobos too, not just your code. It implies that 
these libs are linked statically then.

whileclove <whileclove gmail.com> writes:

On Friday, 13 October 2023 at 09:37:49 UTC, Sergey wrote:
 Based on experience on Debian 
 (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960157) 
 Docker image I found I was required to use 
 "-flto-binary=/usr/lib/LLVMgold.so" in addition to "-flto=full".

 Is it Debian specific issue or required for other distributions 
 as well?

 For example on Archlinux the liblphobos package provides two 
 files:
 - usr/lib/libdruntime-ldc-lto.a
 - usr/lib/libphobos2-ldc-lto.a

 So probably adding 
 "-defaultlib=phobos2-ldc-lto,druntime-ldc-lto" will be fine.

 But is "-flto-binary" is still required? What is it used for?

 Can we please improve some information about proper flags usage 
 for LTO enabled code in LDC?

The issue mentioned in the Debian Bug report you provided 
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=960157) seems 
specific to the Debian distribution and the LDC (LLVM D Compiler) 
package in that context. The bug report highlights that the 
-flto-binary flag needs to be manually specified to locate the 
LLVMgold.so plugin, which is required for Link Time Optimization 
(LTO) in LDC.
https://snake-game.io