Use artifacts on windows to get the compiler

Artifacts.toml

@@ -0,0 +1,9 @@
+[[x86_64-w64-mingw32]]
+git-tree-sha1 = "572b61b5075459e3ed62317e674398166ca98dd4"
+os = "windows"
+arch = "x86_64"
+lazy = true
+
+    [[x86_64-w64-mingw32.download]]
+    sha256 = "fe3f401bc936fbe6af940b26c5e0f266f762a3416f979c706e599b24082dc5c7"
+    url = "https://github.com/JuliaComputing/PackageCompilerX.jl/releases/download/v0.1/x86_64-8.1.0-release-posix-seh-rt_v6-rev0.tar.gz"

docs/src/index.md

@@ -29,9 +29,4 @@ For macOS, using something like `homebrew` and for Linux the system package mana
 
 ### Windows
 
-For Windows, the minGW compiler toolchain is needed. It can be downloaded from e.g.
-[https://sourceforge.net/projects/mingw-w64/files/](https://sourceforge.net/projects/mingw-w64/files/) or by following the 
-instructions for setting up a toolchain capable of compiling Julia itself on Windows at
-[https://github.com/JuliaLang/julia/blob/master/doc/build/windows.md#cygwin-to-mingw-cross-compiling](https://github.com/JuliaLang/julia/blob/master/doc/build/windows.md#cygwin-to-mingw-cross-compiling)
-and then run PackageCompilerX from the cygwin terminal. Alternatively, the package manager
-[chocolatey](https://chocolatey.org/) can be used to get mingw on Windows.
+A suitable compiler will be automatically installed the first time it is neeed.

src/PackageCompilerX.jl

@@ -20,20 +20,28 @@ yesno(b::Bool) = b ? "yes" : "no"
 bitflag() = Int == Int32 ? `-m32` : `-m64`
 march() = (Int == Int32 ? `-march=pentium4` : ``)
 
+function windows_compiler_artifact_path(f, compiler)
+    if Sys.iswindows()
+        withenv("PATH" => string(ENV["PATH"], ";", dirname(compiler))) do
+            f()
+        end
+    else
+        f()
+    end
+end
+
 function get_compiler()
     cc = get(ENV, "JULIA_CC", nothing)
     if cc !== nothing
-        return `$cc`
+        return cc
+    end
+    if Sys.iswindows()
+        return joinpath(Pkg.Artifacts.artifact"x86_64-w64-mingw32", "mingw64", "bin", "gcc.exe")
     end
     if Sys.which("gcc") !== nothing
-        return `gcc`
+        return "gcc"
     elseif Sys.which("clang") !== nothing
-        return `clang`
-    end
-    if Sys.iswindows()
-        if Sys.which("x86_64-w64-mingw32-gcc") !== nothing
-            return `x86_64-w64-mingw32-gcc`
-        end
+        return "clang"
     end
     error("could not find a compiler, looked for `gcc` and `clang`")
 end
@@ -362,9 +370,12 @@ function create_sysimg_from_object_file(input_object::String, sysimage_path::Str
         o_file = `-Wl,--whole-archive $input_object -Wl,--no-whole-archive`
     end
     extra = Sys.iswindows() ? `-Wl,--export-all-symbols` : ``
-    cmd = `$(get_compiler()) $(bitflag()) $(march()) -shared -L$(julia_libdir) -o $sysimage_path $o_file -ljulia $extra`
+    compiler = get_compiler()
+    cmd = `$compiler $(bitflag()) $(march()) -shared -L$(julia_libdir) -o $sysimage_path $o_file -ljulia $extra`
     @debug "running $cmd"
-    run(cmd)
+    windows_compiler_artifact_path(compiler) do
+        run(cmd)
+    end
     return nothing
 end
 
@@ -560,9 +571,13 @@ function create_executable_from_sysimg(;sysimage_path::String,
     else
         rpath = `-Wl,-rpath,\$ORIGIN:\$ORIGIN/../lib`
     end
-    cmd = `$(get_compiler()) -DJULIAC_PROGRAM_LIBNAME=$(repr(sysimage_path)) $(bitflag()) $(march()) -o $(executable_path) $(wrapper) $(sysimage_path) -O2 $rpath $flags`
+    compiler = get_compiler()
+    cmd = `$compiler -DJULIAC_PROGRAM_LIBNAME=$(repr(sysimage_path)) $(bitflag()) $(march()) -o $(executable_path) $(wrapper) $(sysimage_path) -O2 $rpath $flags`
     @debug "running $cmd"
     run(cmd)
+    windows_compiler_artifact_path(compiler) do
+        run(cmd)
+    end
     return nothing
 end