Fix Windows CI build

Recent MSYS2 updates broke the build again. It turns out libff was
being built by referencing the MSYS2-installed headers instead of
the GHC-bundled ones. This adjusts the build process to have libff
built with the same headers as the rest of hevm.

Author: elopez

.github/scripts/install-libff.sh

@@ -21,8 +21,12 @@ git checkout "v$INSTALL_VERSION" && git submodule init && git submodule update
 patch -p1 < ../.github/scripts/libff.patch
 
 sed -i 's/find_library(GMP_LIBRARY gmp)/find_library(GMP_LIBRARY NAMES libgmp.a)/' CMakeLists.txt
+# This ends up causing the system headers to be included with -I and
+# thus they override the GHC mingw compiler ones. So this removes it
+# and re-adds the include with idirafter via the toolchain file
+sed -i '/INCLUDE_DIRECTORIES.*OPENSSL_INCLUDE_DIR/d' CMakeLists.txt
 PREFIX="$HOME/.local"
-ARGS=("-DCMAKE_INSTALL_PREFIX=$PREFIX" "-DWITH_PROCPS=OFF" "-G" "Ninja")
+ARGS=("-DCMAKE_INSTALL_PREFIX=$PREFIX" "-DWITH_PROCPS=OFF" "-G" "Ninja" "-DCMAKE_TOOLCHAIN_FILE=$PWD/../.github/scripts/windows-ghc-toolchain.cmake")
 CXXFLAGS="-fPIC"
 
 mkdir -p build

.github/scripts/windows-ghc-toolchain.cmake

@@ -0,0 +1,12 @@
+set(CMAKE_SYSTEM_NAME Windows)
+
+set(CMAKE_C_COMPILER "$ENV{HASKELL_MINGW_PATH}/bin/cc.exe")
+set(CMAKE_CXX_COMPILER "$ENV{HASKELL_MINGW_PATH}/bin/c++.exe")
+
+set(CMAKE_C_FLAGS "-idirafter D:/a/_temp/msys64/clang64/include")
+set(CMAKE_CXX_FLAGS "-idirafter D:/a/_temp/msys64/clang64/include")
+
+set(CMAKE_FIND_ROOT_PATH "$ENV{HASKELL_MINGW_PATH}")
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM BOTH)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY BOTH)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE BOTH)

.github/workflows/build.yml

@@ -160,11 +160,11 @@ jobs:
         run: |
           export PATH="$HASKELL_PATHS:$PATH"
           cabal configure --disable-documentation --enable-executable-static --enable-executable-stripping \
-            --extra-include-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/x86_64-w64-mingw32/include")" --extra-lib-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/x86_64-w64-mingw32/lib")" \
-            --extra-include-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/include")" --extra-lib-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/lib")" \
-            --extra-include-dirs="D:/a/_temp/msys64/clang64/include" --extra-lib-dirs="D:/a/_temp/msys64/clang64/lib" \
+            --extra-lib-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/x86_64-w64-mingw32/lib")" \
+            --extra-lib-dirs="$(cygpath -m "$HASKELL_MINGW_PATH/lib")" \
+            --extra-lib-dirs="D:/a/_temp/msys64/clang64/lib" \
             --extra-include-dirs="$HOME/.local/include" --extra-lib-dirs="$HOME/.local/lib" \
-            --ghc-options=-pgml="$(cygpath -m "$HASKELL_MINGW_PATH/bin/clang.exe")" -fstatic-secp256k1 --constraint="zlib +bundled-c-zlib"
+            --ghc-options=-pgml="$(cygpath -m "$HASKELL_MINGW_PATH/bin/clang.exe") -optc-idirafter -optcD:/a/_temp/msys64/clang64/include -optcxx-idirafter -optcxxD:/a/_temp/msys64/clang64/include" -fstatic-secp256k1 --constraint="zlib +bundled-c-zlib"
           cabal build --dry-run
           # The last step generates dist-newstyle/cache/plan.json for the cache key.