On Sunday, 19 June 2016 at 16:31:40 UTC, Mike Parker wrote:
On Sunday, 19 June 2016 at 15:35:04 UTC, moe wrote:
I am new to d and doing some small test apps at the moment to
learn d. Currently I must be missing something basic here. I
have installed dub as a project manager and I am trying to use
a .lib file in an app. However, I can not use a module from
the .lib file. I get the following error:
"module barlib is in file 'barlib.d' which cannot be read"
This is a compile time error, not a link time error. Imports
modules and linking to libraries are two different things.
the dub.json for the app
------------------------
{
"name": "dfoo",
"authors": ["moe"],
"description": "A minimal D application.",
"copyright": "Copyright © 2016, root",
"license": "proprietary",
"platforms": ["windows"],
"versions": ["DesktopApp"],
"targetType": "executable",
"configurations": [
{
"name": "debug",
"targetPath": "bin/debug",
"buildOptions": ["debugMode", "debugInfo"]
},
{
"name": "release",
"targetPath": "bin/release",
"buildOptions": ["releaseMode", "optimize", "inline"]
}
]
}
Nowhere have you set up barlib as a dependency for your app, so
DUB has no idea it's supposed to tell dmd that you need to link
to the library or where to find the modules. So the easy thing
to do is to add a dependency directive. Since your library
isn't registered with the dub registry, you'll need to provide
a path to the barlib dub project rather than a release tag for
the library.
Assuming a directory tree like so:
-projects
--barlib
---dub.json
--dfoo
---dub.json
Then the path for dfoo's depencency is ../barlib. With a
dub.sdl file, it would look like this:
dependency "barlib" path="../barlib"
You can find the equivalent JSON syntax somewhere at [1]. With
this, dub will manage your import path and library dependency
for you.
I can successfully build the barlib.lib file but I can not use
it in the app. I thought that it should be possible to simply
import the module from the lib-file, but the app cannot find
the module. I would like to be able to build .lib and .dll
files and use them in other applications. Can someone tell me
what I am missing?
Compiling and linking are two distinct steps. The compiler
passes any libraries you give it to the linker, but it does not
do anything with them itself during the compile step. At that
stage, it's only concerned with source modules. So you need to
tell it: where to find the source modules (on the command
line), which ones to import (with the import statement). It
also needs to know which libraries to pass to the linker and
where they can be found.
Give the directory tree above, when compiling dfoo manually,
you might do this on Windows:
cd dfoo
dmd -I../barlib/source source/app.d ../barlib/bin/barlib.lib
On other systems:
dmd -I../barlib/source -L-L../barlib/bin -L-lbarlib source/app.d
The -I switch tells the compiler where it can find the modules
you need to import. DRuntime and Phobos are configured in DMD's
config files, so you don't need to every specify those. On the
windows command line, you can pass the full path to the library
directly and the compiler will do the right thing. This is
easier than dealing with the different syntax the two supported
Windows linkers use for command line switches. On Posix
systems, it's better to use the -L switch, which tell the
compiler the immediately following command should be passed to
the system linker. Ex:
-L-L/some/path -> passes -L/some/path to the linker, which is
the switch telling it where to look for libraries.
-L-lFoo (-L-l -- the second letter is a lowercase 'L') ->
passes -lname to the linker, telling it which library to link
with.
Given this, the linker will look for /some/path/libFoo.so or
/some/path/libFoo.a, in addition to searching the normal search
paths.
As you can see, it's easier to properly configure your dub.json
dependecies so that DUB can handle all of this for you.
[1] http://code.dlang.org/package-format?lang=json
Thanks for the reply.
Unfortunatelly I still don't get it. I would like to have an
independant project "dbar". The created lib is then used in
another project "dfoo". Assuming that "dfoo" has no access to
"dbar" other than the .lib file.
My folder structure is like this:
-dtest
--dbar
----source\barlib.d
----dub.json
This project creates a dbar.lib file which seams to work.
-dtest
--dfoo
----lib\dbar.d // copied from the dbar project
----source\app.d
----dub.json
This project would use the dbar.lib but should otherwise not have
access to the dbar project. Basically simulating, that someone
else made a dbar project to which I would not have access other
than using the dbar.lib. How do I have to configure the dub.json
file for this to work?
I have tried a variety of configurations for the dub.json. At
this point it feels like a bad guessing game. That is no way to
deveop anything. I need to figure out how to properly setup the
dub.json but I don't seam to find the answer online.
"http://code.dlang.org/package-format?lang=json"; isn't very
helpful.
I have meanwhile adjusted my dtest/dfoo/dub.json to this:
{
"name": "dfoo",
"authors": ["moe"],
"description": "A minimal D application.",
"copyright": "Copyright © 2016, root",
"license": "proprietary",
"platforms": ["windows"],
"versions": ["DesktopApp"],
"targetType": "executable",
"sourcePaths":["lib"],
"libs": ["dbar"],
"copyFiles": ["lib"],
"dependencies": {
"dbar": "~master"
},
"configurations": [
{
"name": "debug",
"targetPath": "bin/debug",
"buildOptions": ["debugMode", "debugInfo"],
},
{
"name": "release",
"targetPath": "bin/release",
"buildOptions": ["releaseMode", "optimize", "inline"],
}
]
}
This gives me the error: "Root package dfoo references unknown
package dbar"
Removing the dependencies doesn't work either.
