Compilation message with MPI extension

Project.toml

@@ -2,3 +2,16 @@ name = "TrixiBase"
 uuid = "9a0f1c46-06d5-4909-a5a3-ce25d3fa3284"
 authors = ["Michael Schlottke-Lakemper <[email protected]>"]
 version = "0.1.0"
+
+[weakdeps]
+MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
+
+[extensions]
+TrixiBaseMPIExt = "MPI"
+
+[compat]
+MPI = "0.20"
+julia = "1.8"
+
+[extras]
+MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"

ext/TrixiBaseMPIExt.jl

@@ -0,0 +1,20 @@
+# Package extension for adding MPI-based features to TrixiBase.jl
+module TrixiBaseMPIExt
+
+# Load package extension code on Julia v1.9 and newer
+if isdefined(Base, :get_extension)
+    using MPI: MPI
+end
+import TrixiBase
+
+# This is a really working version - assuming the same
+# communication pattern etc. used in Trixi.jl.
+function TrixiBase.mpi_isparallel(::Val{:MPIExt})
+    if MPI.Initialized()
+        return MPI.Comm_size(MPI.COMM_WORLD) > 1
+    else
+        return false
+    end
+end
+
+end

src/trixi_include.jl

@@ -39,6 +39,10 @@ function trixi_include(mod::Module, elixir::AbstractString; kwargs...)
         find_assignment(expr, key)
     end
 
+    # Print information on potential wait time only in non-parallel case
+    if !mpi_isparallel(Val{:MPIExt}())
+        @info "You just called `trixi_include`. Julia may now compile the code, please be patient."
+    end
     Base.include(ex -> replace_assignments(insert_maxiters(ex); kwargs...), mod, elixir)
 end
 
@@ -143,3 +147,8 @@ function find_assignment(expr, destination)
 
     result
 end
+
+# This is just a dummy function. We only implement a real
+# version if MPI.jl is loaded to avoid letting TrixiBase.jl
+# depend explicitly on MPI.jl.
+mpi_isparallel(x) = false

test/test_util.jl

@@ -20,9 +20,57 @@ macro trixi_testset(name, expr)
         using Test
         using TrixiBase
 
+        # We also include this file again to provide the definition of
+        # the other testing macros. This allows to use `@trixi_testset`
+        # in a nested fashion and also call `@test_nowarn_mod` from
+        # there.
+        include(@__FILE__)
+
         @testset verbose=true $name $expr
         end
 
         nothing
     end
 end
+
+"""
+    @test_nowarn_mod expr
+
+Modified version of `@test_nowarn expr` that prints the content of `stderr` when
+it is not empty and ignores some common info statements printed in Trixi.jl
+uses.
+"""
+macro test_nowarn_mod(expr, additional_ignore_content = String[])
+    quote
+        let fname = tempname()
+            try
+                ret = open(fname, "w") do f
+                    redirect_stderr(f) do
+                        $(esc(expr))
+                    end
+                end
+                stderr_content = read(fname, String)
+                if !isempty(stderr_content)
+                    println("Content of `stderr`:\n", stderr_content)
+                end
+
+                # Patterns matching the following ones will be ignored. Additional patterns
+                # passed as arguments can also be regular expressions, so we just use the
+                # type `Any` for `ignore_content`.
+                ignore_content = Any["[ Info: You just called `trixi_include`. Julia may now compile the code, please be patient.\n"]
+                append!(ignore_content, $additional_ignore_content)
+                for pattern in ignore_content
+                    stderr_content = replace(stderr_content, pattern => "")
+                end
+
+                # We also ignore simple module redefinitions for convenience. Thus, we
+                # check whether every line of `stderr_content` is of the form of a
+                # module replacement warning.
+                @test occursin(r"^(WARNING: replacing module .+\.\n)*$", stderr_content)
+                ret
+            finally
+                rm(fname, force = true)
+            end
+        end
+    end
+end

test/trixi_include.jl

@@ -12,15 +12,16 @@
 
             # Use `@trixi_testset`, which wraps code in a temporary module, and call
             # `trixi_include` with `@__MODULE__` in order to isolate this test.
-            @test_nowarn trixi_include(@__MODULE__, filename)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename)
             @test @isdefined x
             @test x == 4
 
-            @test_nowarn trixi_include(@__MODULE__, filename, x = 7)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename, x = 7)
+
             @test x == 7
 
             # Verify default version (that includes in `Main`)
-            @test_nowarn trixi_include(filename, x = 11)
+            @test_nowarn_mod trixi_include(filename, x = 11)
             @test Main.x == 11
 
             @test_throws "assignment `y` not found in expression" trixi_include(@__MODULE__,
@@ -101,22 +102,22 @@
             # Use `@trixi_testset`, which wraps code in a temporary module, and call
             # `Base.include` and `trixi_include` with `@__MODULE__` in order to isolate this test.
             Base.include(@__MODULE__, filename1)
-            @test_nowarn trixi_include(@__MODULE__, filename2)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename2)
             @test @isdefined x
             # This is the default `maxiters` inserted by `trixi_include`
             @test x == 10^5
 
-            @test_nowarn trixi_include(@__MODULE__, filename2,
-                                       maxiters = 7)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename2,
+                                           maxiters = 7)
             # Test that `maxiters` got overwritten
             @test x == 7
 
             # Verify that adding `maxiters` to `maxiters` results in exactly one of them
             # case 1) `maxiters` is *before* semicolon in included file
-            @test_nowarn trixi_include(@__MODULE__, filename3, maxiters = 11)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename3, maxiters = 11)
             @test y == 11
             # case 2) `maxiters` is *after* semicolon in included file
-            @test_nowarn trixi_include(@__MODULE__, filename3, maxiters = 14)
+            @test_nowarn_mod trixi_include(@__MODULE__, filename3, maxiters = 14)
             @test y == 14
         finally
             rm(filename1, force = true)