ci: add Windows job

.github/workflows/bitcoin-core-ci.yml

@@ -18,6 +18,8 @@ concurrency:
 
 env:
   BITCOIN_REPO: bitcoin/bitcoin
+  # Temporary: use PR #35084 until it merges; revert to refs/heads/master after
+  BITCOIN_CORE_REF: refs/pull/35084/merge
   LLVM_VERSION: 22
   LIBCXX_DIR: /tmp/libcxx-build/
 
@@ -79,6 +81,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           repository: ${{ env.BITCOIN_REPO }}
+          ref: ${{ env.BITCOIN_CORE_REF }}
           fetch-depth: 1
 
       - name: Checkout libmultiprocess
@@ -195,6 +198,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           repository: ${{ env.BITCOIN_REPO }}
+          ref: ${{ env.BITCOIN_CORE_REF }}
           fetch-depth: 1
 
       - name: Checkout libmultiprocess

.github/workflows/ci.yml

@@ -127,6 +127,25 @@ jobs:
           export PATH="$(brew --prefix llvm)/bin:$PATH"
           CI_CONFIG="ci/configs/macos.bash" bash ci/scripts/ci.sh
 
+  test-windows-cross:
+    runs-on: windows-latest
+    name: test • windows cross
+    needs: build
+    # GitHub-hosted max, nix build is very slow without cache
+    timeout-minutes: 360
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Download Windows artifacts
+        uses: actions/download-artifact@v8
+        with:
+          name: windows-cross-ucrt-build
+          path: windows-cross-artifact
+
+      - name: Run Windows tests
+        shell: pwsh
+        run: ci/scripts/windows_native_test.ps1 -ArtifactRoot windows-cross-artifact
   build:
     runs-on: ubuntu-latest
 
@@ -142,7 +161,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        config: [default, llvm, gnu32, sanitize, olddeps]
+        config: [default, llvm, gnu32, sanitize, olddeps, windows]
 
     name: build • ${{ matrix.config }}
 
@@ -181,3 +200,18 @@ jobs:
         env:
           CI_CONFIG: ci/configs/${{ matrix.config }}.bash
         run: ci/scripts/run.sh
+
+      - name: Package Windows artifacts
+        if: matrix.config == 'windows'
+        env:
+          CI_CONFIG: ci/configs/${{ matrix.config }}.bash
+        run: |
+          source "$CI_CONFIG"
+          nix develop --ignore-environment --keep CI_CONFIG "${NIX_ARGS[@]+"${NIX_ARGS[@]}"}" -f shell.nix --command bash ci/scripts/windows_package.sh
+
+      - name: Upload Windows artifacts
+        if: matrix.config == 'windows'
+        uses: actions/upload-artifact@v7
+        with:
+          name: windows-cross-ucrt-build
+          path: windows-cross-artifact

CMakeLists.txt

@@ -13,7 +13,7 @@ endif()
 include("cmake/compat_find.cmake")
 
 find_package(Threads REQUIRED)
-find_package(CapnProto 0.7 QUIET NO_MODULE)
+find_package(CapnProto 0.9 QUIET NO_MODULE)
  if(NOT CapnProto_FOUND)
    message(FATAL_ERROR
      "Cap'n Proto is required but was not found.\n"
@@ -203,6 +203,10 @@ target_link_libraries(mpgen PRIVATE CapnProto::capnp-rpc)
 target_link_libraries(mpgen PRIVATE CapnProto::capnpc)
 target_link_libraries(mpgen PRIVATE CapnProto::kj)
 target_link_libraries(mpgen PRIVATE Threads::Threads)
+target_compile_definitions(mpgen PRIVATE
+  "CAPNP_EXECUTABLE=\"$<TARGET_FILE:CapnProto::capnp_tool>\""
+  "CAPNPC_CXX_EXECUTABLE=\"$<TARGET_FILE:CapnProto::capnpc_cpp>\""
+  "CAPNP_INCLUDE_DIRS=\"${CAPNP_INCLUDE_DIRS}\"")
 set_target_properties(mpgen PROPERTIES
     INSTALL_RPATH_USE_LINK_PATH TRUE)
 set_target_properties(mpgen PROPERTIES

ci/configs/olddeps.bash

@@ -1,5 +1,5 @@
 CI_DESC="CI job using old Cap'n Proto and cmake versions"
 CI_DIR=build-olddeps
 export CXXFLAGS="-Werror -Wall -Wextra -Wpedantic -Wno-unused-parameter -Wno-error=array-bounds"
-NIX_ARGS=(--argstr capnprotoVersion "0.7.1" --argstr cmakeVersion "3.12.4")
+NIX_ARGS=(--argstr capnprotoVersion "0.9.2" --argstr cmakeVersion "3.12.4")
 BUILD_ARGS=(-k)

ci/configs/windows.bash

@@ -0,0 +1,57 @@
+CI_DESC="CI job cross-compiling to Windows (MinGW UCRT) and testing with Wine"
+CI_DIR=build-windows
+# Cache the cross-toolchain closure to avoid rebuilding mingw + wine every run.
+CI_CACHE_NIX_STORE=true
+
+# Wine needs a writable prefix and XDG_RUNTIME_DIR to talk to its services.
+# Pre-create the prefix outside of the nix shell so we can plumb it through
+# (the shell uses --ignore-environment).
+export WINEPREFIX="${WINEPREFIX:-$HOME/.wine-libmultiprocess}"
+export WINEARCH="${WINEARCH:-win64}"
+export XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"
+mkdir -p "$WINEPREFIX"
+# Silence wine's verbose warnings about missing Windows features during tests.
+export WINEDEBUG=-all
+
+NIX_ARGS=(
+  --arg minimal true
+  --arg enableWine true
+  # Pin capnproto v1.4.0: v1.3.0 includes the upstream fix that moves
+  # cidr.c++ into kj-async (capnproto@a2deb05) so we no longer need a local
+  # patch for that, and v1.4.0 is the current stable release.
+  --arg capnprotoVersion '"1.4.0"'
+  --arg crossPkgs 'import <nixpkgs> { crossSystem = { config = "x86_64-w64-mingw32"; libc = "ucrt"; }; }'
+  # Wine stores its prefix under $HOME; preserve HOME so wineboot can initialize.
+  --keep HOME
+  --keep WINEPREFIX
+  --keep WINEARCH
+  --keep WINEDEBUG
+  --keep XDG_RUNTIME_DIR
+)
+export CXXFLAGS="-Werror -Wall -Wextra -Wpedantic -Wno-unused-parameter -Wa,-mbig-obj"
+
+# When sourced from inside the nix shell (during ci.sh), initialize wine and
+# pick up native capnp tools to use for build-time code generation. These
+# steps are no-ops when sourced from outside the shell (e.g. by run.sh).
+if command -v wineboot >/dev/null 2>&1; then
+  wineboot --init >/dev/null 2>&1 || true
+fi
+CAPNP_NATIVE=$(command -v capnp 2>/dev/null || true)
+CAPNPC_CXX_NATIVE=$(command -v capnpc-c++ 2>/dev/null || true)
+
+CMAKE_ARGS=(
+  -G Ninja
+  # Tell CMake we're targeting Windows so FindThreads picks Win32 threads
+  # and other platform checks behave correctly.
+  -DCMAKE_SYSTEM_NAME=Windows
+  -DCMAKE_SYSTEM_PROCESSOR=x86_64
+  # Run target-arch executables (mpgen, capnpc, mptest) through wine64.
+  -DCMAKE_CROSSCOMPILING_EMULATOR=wine64
+  # Avoid pulling in libgcc_s_seh-1.dll and libstdc++-6.dll at runtime.
+  -DCMAKE_EXE_LINKER_FLAGS="-static-libgcc -static-libstdc++"
+  # Use native capnp/capnpc-c++ for build-time code generation so cmake
+  # doesn't try to exec target-arch .exe binaries directly.
+  ${CAPNP_NATIVE:+-DCAPNP_EXECUTABLE=$CAPNP_NATIVE}
+  ${CAPNPC_CXX_NATIVE:+-DCAPNPC_CXX_EXECUTABLE=$CAPNPC_CXX_NATIVE}
+)
+BUILD_ARGS=(-k 0)

ci/patches/capnproto-wine-invalid-function.patch

@@ -0,0 +1,36 @@
+From: libmultiprocess CI <ci@invalid>
+Subject: [PATCH] kj: Treat ERROR_INVALID_FUNCTION from
+ GetFileInformationByHandleEx as non-fatal
+
+Wine's NtQueryInformationFile returns STATUS_NOT_IMPLEMENTED for any
+FILE_INFORMATION_CLASS it does not handle (see the default case in
+dlls/ntdll/unix/file.c:NtQueryInformationFile in the wine source).
+RtlNtStatusToDosError maps STATUS_NOT_IMPLEMENTED (0xC0000002) to
+ERROR_INVALID_FUNCTION (1), so GetFileInformationByHandleEx returns 1
+when called with FileCompressionInfo (and other classes Wine doesn't
+implement) instead of the ERROR_CALL_NOT_IMPLEMENTED (120) that the
+existing fallback expects. Without this, cap'n proto's KJ filesystem
+layer throws an uncaught exception when running cross-compiled capnp.exe
+under Wine. Treat ERROR_INVALID_FUNCTION the same way: skip the sparse
+file space-usage query and continue.
+
+Forwarded: https://github.com/capnproto/capnproto/pull/2633
+Drop once that PR is merged and a release containing it is pinned.
+---
+ c++/src/kj/filesystem-disk-win32.c++ | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/c++/src/kj/filesystem-disk-win32.c++
++++ b/c++/src/kj/filesystem-disk-win32.c++
+@@ -380,6 +380,11 @@
+       case ERROR_CALL_NOT_IMPLEMENTED:
+         // Probably WINE.
+       	break;
++      case ERROR_INVALID_FUNCTION:
++        // Also WINE: NtQueryInformationFile returns STATUS_NOT_IMPLEMENTED for
++        // unsupported FileInfoClass values, which RtlNtStatusToDosError maps to
++        // ERROR_INVALID_FUNCTION (not ERROR_CALL_NOT_IMPLEMENTED).
++        break;
+       case ERROR_INVALID_PARAMETER:
+         // Probably VeraCrypt. See https://github.com/capnproto/capnproto/issues/2176
+         break;

ci/scripts/windows_native_test.ps1

@@ -0,0 +1,39 @@
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$ArtifactRoot
+)
+
+# Copyright (c) The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+
+$ErrorActionPreference = "Stop"
+# Prevent PowerShell 7 from turning native-command stderr into a terminating
+# error before we get a chance to see it.
+$PSNativeCommandUseErrorActionPreference = $false
+
+$artifactPath = (Resolve-Path $ArtifactRoot).Path
+$env:PATH = "$artifactPath;$env:PATH"
+
+$mptest = Join-Path $artifactPath "test\mptest.exe"
+& $mptest 2>&1 | ForEach-Object { "$_" }
+$code = $LASTEXITCODE
+Write-Host ("mptest exit code: {0} (0x{0:X8})" -f $code)
+if ($code -ne 0) {
+    exit $code
+}
+
+$exampleDir = Join-Path $artifactPath "example"
+Push-Location $exampleDir
+try {
+    $output = "2+2`nexit`n" | & ".\mpexample.exe" 2>&1 | Out-String
+    Write-Host $output
+    if ($LASTEXITCODE -ne 0) {
+        exit $LASTEXITCODE
+    }
+    if ($output -notmatch "mpprinter:" -or $output -notmatch "Bye!") {
+        throw "Unexpected mpexample output."
+    }
+} finally {
+    Pop-Location
+}

ci/scripts/windows_package.sh

@@ -0,0 +1,97 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+#
+# Package cross-compiled Windows binaries + runtime DLLs into a directory
+# suitable for uploading as a workflow artifact. Must be run inside the
+# nix shell produced by `ci/configs/windows.bash` so the mingw toolchain
+# (objdump, g++) is on PATH.
+
+export LC_ALL=C.UTF-8
+
+set -o errexit -o nounset -o pipefail -o xtrace
+
+readonly SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+readonly REPO_DIR="$(cd -- "${SCRIPT_DIR}/../.." && pwd)"
+
+[ "${CI_CONFIG+x}" ] && source "$CI_CONFIG"
+: "${CI_DIR:=build-windows}"
+
+readonly BUILD_DIR="${REPO_DIR}/${CI_DIR}"
+readonly ARTIFACT_DIR="${REPO_DIR}/windows-cross-artifact"
+
+# Nix's cross stdenv exports these; fall back to the canonical names if not.
+: "${CXX:=x86_64-w64-mingw32-g++}"
+: "${OBJDUMP:=x86_64-w64-mingw32-objdump}"
+
+copy_artifact_file() {
+  install -D -m 0755 "$1" "${ARTIFACT_DIR}/$2"
+}
+
+# Runtime DLLs for cross-compiled dependencies live in the sibling bin/
+# directory of each -L path the cross stdenv adds to NIX_LDFLAGS (e.g.
+# capnproto, mcfgthreads). Collect those bin/ dirs once for dll lookup.
+EXTRA_DLL_DIRS=()
+for flag in ${NIX_LDFLAGS:-}; do
+  case "${flag}" in
+    -L*)
+      candidate="${flag#-L}/../bin"
+      [[ -d "${candidate}" ]] && EXTRA_DLL_DIRS+=("${candidate}")
+      ;;
+  esac
+done
+
+copy_runtime_dlls() {
+  local exe="$1"
+  local dll dll_path dir
+  while read -r dll; do
+    [[ -n "${dll}" ]] || continue
+    # Skip DLLs that ship with Windows / Wine.
+    case "${dll}" in
+      ADVAPI32.dll|COMBASE.dll|COMCTL32.dll|GDI32.dll|KERNEL32.dll|OLE32.dll|OLEAUT32.dll|RPCRT4.dll|SHELL32.dll|UCRTBASE.dll|USER32.dll|WS2_32.dll)
+        continue
+        ;;
+    esac
+    dll_path="$(${CXX} -print-file-name="${dll}")"
+    if [[ "${dll_path}" == "${dll}" || ! -f "${dll_path}" ]]; then
+      dll_path=""
+      for dir in "${EXTRA_DLL_DIRS[@]+"${EXTRA_DLL_DIRS[@]}"}"; do
+        if [[ -f "${dir}/${dll}" ]]; then
+          dll_path="${dir}/${dll}"
+          break
+        fi
+      done
+    fi
+    if [[ -z "${dll_path}" || ! -f "${dll_path}" ]]; then
+      case "${dll}" in
+        lib*.dll)
+          echo "Could not locate runtime DLL ${dll}." >&2
+          exit 1
+          ;;
+        *)
+          continue
+          ;;
+      esac
+    fi
+    install -D -m 0755 "${dll_path}" "${ARTIFACT_DIR}/${dll}"
+  done < <(${OBJDUMP} -p "${exe}" | awk '/DLL Name: / {print $3}' | sort -u)
+}
+
+rm -rf "${ARTIFACT_DIR}"
+
+readonly EXES=(
+  test/mptest.exe
+  example/mpexample.exe
+  example/mpcalculator.exe
+  example/mpprinter.exe
+)
+
+for exe in "${EXES[@]}"; do
+  copy_artifact_file "${BUILD_DIR}/${exe}" "${exe}"
+done
+
+for exe in "${EXES[@]}"; do
+  copy_runtime_dlls "${BUILD_DIR}/${exe}"
+done