Add requirements & MinGW instructions to READMEs. Change OS/ARCH to GOOS/GOARCH. Add build step to Python test Makefile.

5 files changed, 68 insertions, 11 deletions

diff --git a/README.md b/README.md
index 8968654..4919bef 100644
--- a/README.md
+++ b/README.md
@@ -11,31 +11,63 @@ each language used in EduVPN clients to easily interface with the library.
 Currently, only verification of signatures on files from `disco.eduvpn.org` is supported. For now, these files have to
 be downloaded by the caller.
 
+## Requirements
+
+To run the Go tests, you will need [Go](https://go.dev/doc/install) 1.15 or later (add it to your `PATH`). To build the
+shared library, you will additionally need to install gcc. If you want to use the Makefile scripts you will need GNU
+make.
+
+On Windows, you can install gcc and make (or even Go) via MinGW or Cygwin or use WSL. For MinGW:
+
+1. [Install MinGW](https://www.msys2.org/#installation) (you don't need to install any extra packages yet) and open some
+   MSYS2 terminal (e.g. from the start menu or one of the installed binaries)
+2. Install the [`make`](https://packages.msys2.org/package/make?repo=msys) package (`pacman -S make`) (or
+   e.g. [`mingw-w64-x86_64-make`](https://packages.msys2.org/package/mingw-w64-x86_64-make?repo=mingw64) and
+   use `mingw32-make` in the command line)
+3. To compile for x86_64:
+   1. Install the [`mingw-w64-x86_64-gcc`](https://packages.msys2.org/package/mingw-w64-x86_64-gcc?repo=mingw64) package
+   2. Open the MinGW 64-bit console, via the start menu, or in your current
+      terminal: `path/to/msys64/msys2_shell.cmd -mingw64 -defterm -no-start -use-full-path`
+   3. Run the make commands in the project directory
+4. To compile for x86 (32-bit):
+   1. Install the [`mingw-w64-i686-gcc`](https://packages.msys2.org/package/mingw-w64-i686-gcc?repo=mingw32) package
+   2. Open the MinGW 32-bit console, via the start menu, or in your current
+      terminal: `path/to/msys64/msys2_shell.cmd -mingw32 -defterm -no-start -use-full-path`
+   3. Run the make commands in the project directory
+
+Take a look at `wrappers/<lang>/README.md` for extra instructions for each wrapper.
+
 ## Build & test
 
 Build shared library for current platform:
+
 ```shell
 make
 ```
 
 Build shared library for specified OS & architecture (example):
+
 ```shell
-make OS=windows ARCH=386
+make GOOS=windows GOARCH=386
 ```
 
 Results will be output in `exports/`.
 
+TODO: notes on cross-compilation
+
 Test Go code:
+
 ```shell
 make test-go
 ```
 
-Test wrappers:
+Test wrappers (you will need compilers for all wrappers if you do this):
+
 ```shell
 make test-wrappers
 ```
 
-Take a look at `wrappers/<lang>/` for descriptions per wrapper.
+Take a look at `wrappers/<lang>/README.md` for descriptions per wrapper.
 
 ## Directory
 
diff --git a/exports/Makefile b/exports/Makefile
index 912e930..fdedba2 100644
--- a/exports/Makefile
+++ b/exports/Makefile
@@ -4,15 +4,15 @@ lib_suffix_linux   = .so
 lib_suffix_windows = .dll
 lib_suffix_darwin  = .dylib
 
-OS         = $(shell go env GOHOSTOS)
-ARCH       = $(shell go env GOHOSTARCH)
-LIB_SUFFIX = $(lib_suffix_$(OS))
+GOOS      ?= $(shell go env GOHOSTOS)
+GOARCH    ?= $(shell go env GOHOSTARCH)
+LIB_SUFFIX = $(lib_suffix_$(GOOS))
 
 # Creates targets like 'linux/amd64/eduvpn_verify.so'
-build: $(OS)/$(ARCH)/eduvpn_verify$(LIB_SUFFIX)
+build: $(GOOS)/$(GOARCH)/eduvpn_verify$(LIB_SUFFIX)
 
-$(OS)/$(ARCH)/eduvpn_verify$(LIB_SUFFIX): exports.go ../verify.go
-	CGO_ENABLED=1 GOOS=$(OS) GOARCH=$(ARCH) go build -o $@ -buildmode=c-shared $<
+$(GOOS)/$(GOARCH)/eduvpn_verify$(LIB_SUFFIX): exports.go ../verify.go
+	CGO_ENABLED=1 GOOS=$(GOOS) GOARCH=$(GOARCH) go build -o $@ -buildmode=c-shared $<
 
 clean:
 	rm -rf ../exports/*/
diff --git a/wrappers/csharp/README.md b/wrappers/csharp/README.md
index 4b045ac..d4d1d97 100644
--- a/wrappers/csharp/README.md
+++ b/wrappers/csharp/README.md
@@ -1,21 +1,37 @@
+# C# wrapper
+
+## Requirements
+
+You will need to install the [.NET SDK](https://dotnet.microsoft.com/download), which includes the `dotnet` tool. The
+wrapper targets .NET Standard 2.0, so which means that at least .NET Core 2.0 is required (.NET 5+ is also fine). For
+the tests, .NET 5 or newer is required.
+
+## Build & test
+
 First build the shared Go library. Next:
 
 Build `EduVpnCommon`:
+
 ```shell
 make
 ```
 
 Build as nupkg, including eduvpn_verify library:
+
 ```shell
 make pack
 ```
 
-Currently, directly referencing the project may not work if you have multiple dynamic libraries compiled in
-the `exports` folder. If you instead add the `.nupkg`, e.g. with one of the
+The wrapper targets .NET Standard 2.0, which means that it can be referenced by projects using either .NET Framework
+4.6.1+, .NET Core 2.0+, or .NET 5+.
+
+Currently, directly referencing the project may not work (with `System.BadImageFormatException`) if you have multiple
+dynamic libraries compiled in the `exports` folder. If you instead add the `.nupkg`, e.g. with one of the
 methods [here](https://stackoverflow.com/q/43400069) or [here](https://stackoverflow.com/q/10240029), it automatically
 copies the correct library.
 
 Test:
+
 ```shell
 make test
 ```
diff --git a/wrappers/python/Makefile b/wrappers/python/Makefile
index 162b043..77c620e 100644
--- a/wrappers/python/Makefile
+++ b/wrappers/python/Makefile
@@ -4,4 +4,5 @@ compile:
 	python3 -m discovery
 
 test:
+	$(MAKE) -C ../../exports
 	python3 -m unittest test_discovery
diff --git a/wrappers/python/README.md b/wrappers/python/README.md
index f10e5ad..fddcde6 100644
--- a/wrappers/python/README.md
+++ b/wrappers/python/README.md
@@ -1,3 +1,11 @@
+# Python wrapper
+
+## Requirements
+
+Python 3.6+ is assumed, but it may work with older versions.
+
+## Test
+
 First build the shared Go library. Next:
 
 No dependencies, just reference `discovery.py` and call `verify`.