Custom installations of Gmsh via Preferences.jl

.github/workflows/CI.yml

@@ -36,3 +36,35 @@ jobs:
       - uses: codecov/codecov-action@v1
         with:
           file: lcov.info
+  test-custom-gmsh:
+    name: Gmsh SDK - Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ github.event_name }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        version:
+          - '1'
+        os:
+          - ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.version }}
+      - uses: julia-actions/julia-buildpkg@v1
+      - name: Install Gmsh SDK dependencies
+        run: sudo apt-get install -y libglu1-mesa
+      - name: Install Gmsh SDK
+        run: |
+          curl -OL https://gmsh.info/bin/Linux/gmsh-4.12.2-Linux64-sdk.tgz
+          tar xvf gmsh-4.12.2-Linux64-sdk.tgz
+          mv gmsh-4.12.2-Linux64-sdk /opt/
+      - name: Configure Gmsh preferences
+        shell: julia --color=yes --project=. {0}
+        run: |
+            using Gmsh
+            Gmsh.use_system_gmsh(;gmsh_jl_dir="/opt/gmsh-4.12.2-Linux64-sdk/lib")
+      - uses: julia-actions/julia-runtest@v1
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v1
+        with:
+          file: lcov.info

Project.toml

@@ -4,9 +4,12 @@ authors = ["Jukka Aho <[email protected]>"]
 version = "0.3.1"
 
 [deps]
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+Preferences = "21216c6a-2e73-6563-6e65-726566657250"
 gmsh_jll = "630162c2-fc9b-58b3-9910-8442a8a132e6"
 
 [compat]
+Preferences = "1"
 gmsh_jll = "4.11"
 julia = "1"
 

src/Gmsh.jl

@@ -1,10 +1,141 @@
 module Gmsh
 
-import gmsh_jll
-include(gmsh_jll.gmsh_api)
+@static if VERSION >= v"1.6"
+    using Preferences
+end
+
+@static if VERSION >= v"1.6"
+    gmsh_provider = @load_preference("gmsh_provider","gmsh_jll")
+else
+    gmsh_provider = "gmsh_jll"
+end
+
+# The logic behind the preferences is inspired by the one found in PetscCall.jl
+
+if gmsh_provider ∉ ("gmsh_jll","system")
+    error("gmsh_provider is either gmsh_jll or system")
+end
+
+@static if gmsh_provider == "gmsh_jll"
+    import gmsh_jll
+    const gmsh_api = gmsh_jll.gmsh_api
+end
+
+@static if gmsh_provider == "system"
+    const gmsh_jl_dir = @load_preference("gmsh_jl_dir","") 
+    if gmsh_jl_dir == ""
+        error("Using a system gmsh installation but gmsh_jl_dir not found in Preferences.toml file")
+    end
+    const gmsh_api = joinpath(gmsh_jl_dir,"gmsh.jl")
+end
+
+include(gmsh_api)
 import .gmsh
 export gmsh
 
+@static if gmsh_provider == "system"
+    using Libdl
+    function __init__()
+        # This is just to have a better idea why gmsh.lib is empty
+        @static if Sys.isunix()
+            if gmsh.lib == ""
+                gmsh_lib = joinpath(gmsh_jl_dir,"libgmsh")
+                Libdl.dlopen(gmsh_lib, Libdl.RTLD_LAZY | Libdl.RTLD_DEEPBIND)
+            end
+        end
+        if gmsh.lib == ""
+            error("The gmsh.jl API file was not able to find a gmsh libary. Some dependencies are provably not installed in the system.")
+        end
+    end
+end
+
+"""
+    Gmsh.use_gmsh_jll()
+
+Configure Gmsh to use the binary provided by gmsh_jll.
+"""
+function use_gmsh_jll()
+    @static if VERSION >= v"1.6"
+        gmsh_provider = "gmsh_jll"
+        @set_preferences!(
+                          "gmsh_provider"=>gmsh_provider,
+                         )
+        msg = """
+        Gmsh preferences changed!
+        The new preferences are:
+        gmsh_provider = $(gmsh_provider)
+        Restart Julia for these changes to take effect.
+        """
+        @info msg
+    end
+    nothing
+end
+
+"""
+    Gmsh.use_system_gmsh([;gmsh_jl_dir])
+
+Configure Gmsh to use the binary provided by a system installation.
+Key-word argument `gmsh_jl_dir` contains the path of the directory containing `gmsh.jl`, the file with
+the Julia API of gmsh. This file needs to be installed as part of the SDK of gmsh.
+If `gmsh_jl_dir` is omitted, this function will look for `gmsh.jl` in `LD_LIBRARY_PATH`.
+"""
+function use_system_gmsh(;gmsh_jl_dir=nothing)
+    @static if VERSION >= v"1.6"
+        function findindir(route,fn)
+            files = readdir(route,join=false)
+            for file in files
+                if file == fn
+                    gmsh_jl_dir = joinpath(route,file)
+                    return gmsh_jl_dir
+                end
+            end
+            nothing
+        end
+        if gmsh_jl_dir === nothing
+            if haskey(ENV,"LD_LIBRARY_PATH") && ENV["LD_LIBRARY_PATH"] != ""
+                routes = split(ENV["LD_LIBRARY_PATH"],':')
+                for route in routes
+                    gmsh_jl_dir = findindir(route,"gmsh.jl")
+                    if gmsh_jl_dir !== nothing
+                        @info "Gmsh Julia API found in the system at $(gmsh_jl_dir)."
+                        break
+                    end
+                end
+            end
+        end
+        if gmsh_jl_dir === nothing
+            msg = """
+            Unable to find a Gmsh installation in the system.
+
+            We looked for the Gmsh Julia API file gmsh.jl in the folders in LD_LIBRARY_PATH.
+
+            You can also manualy specify the route with the key-word argument gmsh_jl_dir.
+
+            Example
+            =======
+
+            julia> using Gmsh
+            julia> using Gmsh.use_system_gmsh(;gmsh_jl_dir="path/to/gmsh.jl")
+            """
+            error(msg)
+        end
+        gmsh_provider = "system"
+        @set_preferences!(
+                          "gmsh_provider"=>gmsh_provider,
+                          "gmsh_jl_dir"=>gmsh_jl_dir,
+                         )
+        msg = """
+        Gmsh preferences changed!
+        The new preferences are:
+        gmsh_provider = $(gmsh_provider)
+        gmsh_jl_dir = $(gmsh_jl_dir)
+        Restart Julia for these changes to take effect.
+        """
+        @info msg
+    end
+    nothing
+end
+
 """
     Gmsh.initialize(argv=String[]; finalize_atexit=true)
 
@@ -52,4 +183,4 @@ function finalize()
     end
 end
 
-end
+end # module