Merge pull request #145 from omlins/examples-update

Enable triggering extension without explicit import

src/ParallelKernel/Exceptions.jl

@@ -1,12 +1,13 @@
 module Exceptions
-export @ModuleInternalError, @MethodPluginError, @IncoherentCallError, @NotInitializedError, @NotLoadedError, @IncoherentArgumentError, @KeywordArgumentError, @ArgumentEvaluationError, @ArgumentError
-export ModuleInternalError, MethodPluginError, IncoherentCallError, NotInitializedError, NotLoadedError, IncoherentArgumentError, KeywordArgumentError, ArgumentEvaluationError
+export @ModuleInternalError, @MethodPluginError, @IncoherentCallError, @NotInitializedError, @NotLoadedError, @NotInstalledError, @IncoherentArgumentError, @KeywordArgumentError, @ArgumentEvaluationError, @ArgumentError
+export ModuleInternalError, MethodPluginError, IncoherentCallError, NotInitializedError, NotLoadedError, NotInstalledError, IncoherentArgumentError, KeywordArgumentError, ArgumentEvaluationError
 
 macro ModuleInternalError(msg) esc(:(throw(ModuleInternalError($msg)))) end
 macro MethodPluginError(msg) esc(:(throw(MethodPluginError($msg)))) end
 macro IncoherentCallError(msg) esc(:(throw(IncoherentCallError($msg)))) end
 macro NotInitializedError(msg) esc(:(throw(NotInitializedError($msg)))) end
 macro NotLoadedError(msg)  esc(:(throw(NotLoadedError($msg)))) end
+macro NotInstalledError(msg)  esc(:(throw(NotInstalledError($msg)))) end
 macro IncoherentArgumentError(msg) esc(:(throw(IncoherentArgumentError($msg)))) end
 macro KeywordArgumentError(msg) esc(:(throw(KeywordArgumentError($msg)))) end
 macro ArgumentEvaluationError(msg) esc(:(throw(ArgumentEvaluationError($msg)))) end
@@ -37,6 +38,11 @@ struct NotLoadedError <: Exception
 end
 Base.showerror(io::IO, e::NotLoadedError) = print(io, "NotLoadedError: ", e.msg)
 
+struct NotInstalledError <: Exception
+    msg::String
+end
+Base.showerror(io::IO, e::NotInstalledError) = print(io, "NotInstalledError: ", e.msg)
+
 struct IncoherentArgumentError <: Exception
     msg::String
 end

src/ParallelKernel/init_parallel_kernel.jl

@@ -27,17 +27,22 @@ end
 
 function init_parallel_kernel(caller::Module, package::Symbol, numbertype::DataType, inbounds::Bool; datadoc_call=:())
     if package == PKG_CUDA
+        if (!CUDA_IS_INSTALLED) @NotInstalledError("CUDA was selected as package for parallelization, but CUDA.jl is not installed. CUDA functionality is provided with an extension of ParallelStencil and CUDA.jl needs therefore to be installed independently.") end
         indextype          = INT_CUDA
         data_module        = Data_cuda(numbertype, indextype)
         data_module_shared = Data_shared(numbertype, indextype)
+        pkg_import_cmd     = :(import CUDA)
     elseif package == PKG_AMDGPU
+        if (!AMDGPU_IS_INSTALLED) @NotInstalledError("AMDGPU was selected as package for parallelization, but AMDGPU.jl is not installed. AMDGPU functionality is provided with an extension of ParallelStencil and AMDGPU.jl needs therefore to be installed independently.") end
         indextype          = INT_AMDGPU
         data_module        = Data_amdgpu(numbertype, indextype)
         data_module_shared = Data_shared(numbertype, indextype)
+        pkg_import_cmd     = :(import AMDGPU)
     elseif package == PKG_THREADS
         indextype          = INT_THREADS
         data_module        = Data_threads(numbertype, indextype)
         data_module_shared = Data_shared(numbertype, indextype)
+        pkg_import_cmd     = :()
     end
     ad_init_cmd = :(ParallelStencil.ParallelKernel.AD.init_AD(ParallelStencil.ParallelKernel.PKG_THREADS))
     if !isdefined(caller, :Data) || (@eval(caller, isa(Data, Module)) &&  length(symbols(caller, :Data)) == 1)  # Only if the module Data does not exist in the caller or is empty, create it.
@@ -46,6 +51,7 @@ function init_parallel_kernel(caller::Module, package::Symbol, numbertype::DataT
             else                               datadoc_call = :(@doc ParallelStencil.ParallelKernel.DATA_DOC Data)
             end
         end
+        @eval(caller, $pkg_import_cmd)
         @eval(caller, $data_module)
         @eval(caller.Data, $data_module_shared)
         @eval(caller, $datadoc_call)

src/ParallelKernel/shared.jl

@@ -10,6 +10,8 @@ gensym_world(tag::String, generator::Module) = gensym(string(tag, GENSYM_SEPARAT
 gensym_world(tag::Symbol, generator::Module) = gensym(string(tag, GENSYM_SEPARATOR, generator))
 gensym_world(tag::Expr,   generator::Module) = gensym(string(tag, GENSYM_SEPARATOR, generator))
 
+const CUDA_IS_INSTALLED            = (Base.find_package("CUDA")!==nothing)
+const AMDGPU_IS_INSTALLED          = (Base.find_package("AMDGPU")!==nothing)
 const PKG_CUDA                     = :CUDA
 const PKG_AMDGPU                   = :AMDGPU
 const PKG_THREADS                  = :Threads

src/ParallelStencil.jl

@@ -42,7 +42,7 @@ https://github.com/omlins/ParallelStencil.jl
 - [`Data`](@ref)
 
 !! note "Activation of GPU support"
-    The support for GPU (CUDA or AMDGPU) is activated by importing the corresponding module (CUDA or AMDGPU) before importing ParallelStencil (the corresponding extension will be loaded).
+    The support for GPU (CUDA or AMDGPU) is provided with extensions and requires therefore an explicit installation of the corresponding packages (CUDA.jl or AMDGPU.jl). Note that it is not required to import explicitly the corresponding module (CUDA or AMDGPU); this is automatically done by [`@init_parallel_stencil`](@ref).
 
 To see a description of a macro or module type `?<macroname>` (including the `@`) or `?<modulename>`, respectively.
 """