• Carl Sturtivant (6/6) Oct 16 2018 Can't find any Windows specific docs for ldc2.
• Carl Sturtivant (44/50) Oct 16 2018 I have determined that the vcvars batch file that comes with the
• kinke (14/19) Oct 16 2018 The LDC package contains a README.txt. Quoting: 'If run in a 'VS
• kinke (7/8) Oct 16 2018 PS:
• kinke (8/10) Oct 16 2018 PPS: Not really required (e.g., with `-link-internally` or with
• Carl Sturtivant (7/17) Oct 16 2018 Thanks for all the very useful information! Much appreciated.
• Carl Sturtivant (20/26) Oct 23 2018 Specifically for persons new to D on windows who want to follow

Carl Sturtivant <sturtivant gmail.com> writes:

Can't find any Windows specific docs for ldc2.

I want to know which environment variables specific to Windows 
ldc2 listens to so as to find the linker and libs so as to speed 
up linking by not searching for a Visual Whatever installation 
every time.

Anyone?

Carl Sturtivant <sturtivant gmail.com> writes:

On Tuesday, 16 October 2018 at 16:43:38 UTC, Carl Sturtivant 
wrote:
 Can't find any Windows specific docs for ldc2.

 I want to know which environment variables specific to Windows 
 ldc2 listens to so as to find the linker and libs so as to 
 speed up linking by not searching for a Visual Whatever 
 installation every time.

 Anyone?

I have determined that the vcvars batch file that comes with the 
windows 10 sdk sets the following new variables for 64 bit 
development on windows 10 64-bit. It also adds to Path, which I 
would prefer to avoid. Some of these are obviously irrelevant, 
but which ones does ldc2 actually use to speed up linking?

I could use intuition and experiment, but it would be nice if 
someone would just point me to docs or tell me the answer.

CommandPromptType
DevEnvDir
ExtensionSdkDir
Framework40Version
FrameworkDir
FrameworkDir64
FrameworkVersion
FrameworkVersion64
INCLUDE
LIB
LIBPATH
Platform
UCRTVersion
UniversalCRTSdkDir
VCIDEInstallDir
VCINSTALLDIR
VCToolsInstallDir
VCToolsRedistDir
VCToolsVersion
VS150COMNTOOLS
VSCMD_ARG_HOST_ARCH
VSCMD_ARG_TGT_ARCH
VSCMD_ARG_app_plat
VSCMD_VER
VSINSTALLDIR
VisualStudioVersion
WindowsLibPath
WindowsSDKLibVersion
WindowsSDKVersion
WindowsSdkBinPath
WindowsSdkDir
WindowsSdkVerBinPath
__DOTNET_ADD_64BIT
__DOTNET_PREFERRED_BITNESS
__VSCMD_PREINIT_PATH

kinke <kinke libero.it> writes:

On Tuesday, 16 October 2018 at 16:43:38 UTC, Carl Sturtivant 
wrote:
 Can't find any Windows specific docs for ldc2.

 I want to know which environment variables specific to Windows 
 ldc2 listens to so as to find the linker and libs so as to 
 speed up linking by not searching for a Visual Whatever 
 installation every time.

The LDC package contains a README.txt. Quoting: 'If run in a 'VS 
Native/Cross Tools Command Prompt' (i.e., if the environment 
variable VSINSTALLDIR is set), LDC skips the Visual C++ 
detection.'

Spawning a new VS command prompt ('shell', cmd.exe with env 
variables set up by the MS batch file) and invoking LDC in that 
shell is the preferred way of skipping that ~1-second linking 
overhead, at least that's how I do things all the time.
If for whatever reason you don't want all of those MS env 
variables, you'll just need VSINSTALLDIR to prevent LDC from 
autodetecting and then the env variables expected by the MS 
linker (LIB and LIBPATH may be enough, I don't remember).

kinke <kinke libero.it> writes:

On Tuesday, 16 October 2018 at 17:34:41 UTC, kinke wrote:
 [...]

PS:
* In case you haven't noticed, there are startmenu shortcuts to 
the VS command prompts, at least with a full VS installation, not 
sure about the Build Tools.
* PATH is also required, LDC invokes `link.exe`. Make sure 
there's no DMD link.exe in PATH. ;)

kinke <noone nowhere.com> writes:

On Tuesday, 16 October 2018 at 17:38:48 UTC, kinke wrote:
 * PATH is also required, LDC invokes `link.exe`. Make sure 
 there's no DMD link.exe in PATH. ;)

PPS: Not really required (e.g., with `-link-internally` or with 
`-linker=<path\to\link.exe>`). You can also specify the lib dirs 
as linker flags via `-L/LIBPATH:<dir1> -L/LIBPATH:<dir2>` in the 
LDC command line, so that you don't need that env variable 
either. You can put these switches into the etc\ldc2.conf file to 
make them implicit. All you should really need is setting 
VSINSTALLDIR to something non-empty.

Carl Sturtivant <sturtivant gmail.com> writes:

On Tuesday, 16 October 2018 at 19:09:26 UTC, kinke wrote:
 On Tuesday, 16 October 2018 at 17:38:48 UTC, kinke wrote:
 * PATH is also required, LDC invokes `link.exe`. Make sure 
 there's no DMD link.exe in PATH. ;)

 PPS: Not really required (e.g., with `-link-internally` or with 
 `-linker=<path\to\link.exe>`). You can also specify the lib 
 dirs as linker flags via `-L/LIBPATH:<dir1> -L/LIBPATH:<dir2>` 
 in the LDC command line, so that you don't need that env 
 variable either. You can put these switches into the 
 etc\ldc2.conf file to make them implicit. All you should really 
 need is setting VSINSTALLDIR to something non-empty.

Thanks for all the very useful information! Much appreciated.

Based upon all this I tried first setting VSINSTALLDIR and adding 
to PATH the path to the linker. And setting LIB. (Apparently 
LIBPATH is for the compiler, not the linker.) This did the job! 
I'll put the path to the linker and the directories in LIB into 
switches in etc/ldc2.conf and I'll have a clean setup.

Carl Sturtivant <sturtivant gmail.com> writes:

On Tuesday, 16 October 2018 at 20:14:03 UTC, Carl Sturtivant 
wrote:
 Based upon all this I tried first setting VSINSTALLDIR and 
 adding to PATH the path to the linker. And setting LIB. 
 (Apparently LIBPATH is for the compiler, not the linker.) This 
 did the job! I'll put the path to the linker and the 
 directories in LIB into switches in etc/ldc2.conf and I'll have 
 a clean setup.

Specifically for persons new to D on windows who want to follow 
in these footsteps, the values needed proved to be as follows on 
64 bit Windows 10.

I obtained these by running the commands listed below in a `x64 
Native Tools Command Prompt for VS 2017` under `Visual Studio 
2017\Visual Studio Tools\VC` from the start menu. Probably you 
should do that.


VSINSTALLDIR
from `echo %VSINSTALLDIR%`
C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\

LIB
from `echo %LIB%`
C:\Program Files (x86)\Microsoft Visual 
Studio\2017\BuildTools\VC\Tools\MSVC\14.15.26726\lib\x64;C:\Program Files
(x86)\Windows Kits\10\lib\10.0.17134.0\ucrt\x64;C:\Program Files (x86)\Windows
Kits\10\lib\10.0.17134.0\um\x64;

PATH --- addition to PATH needed to find link.exe
from `where link`
C:\Program Files (x86)\Microsoft Visual 
Studio\2017\BuildTools\VC\Tools\MSVC\14.15.26726\bin\Hostx64\x64\