GH-41990: [C++] Fix AzureFileSystem compilation on Windows

.github/workflows/cpp_windows.yml

@@ -41,12 +41,14 @@ jobs:
     runs-on: ${{ inputs.os }}
     timeout-minutes: 60
     env:
+      ARROW_AZURE: ON
       ARROW_BOOST_USE_SHARED: OFF
       ARROW_BUILD_BENCHMARKS: ON
       ARROW_BUILD_SHARED: ON
       ARROW_BUILD_STATIC: OFF
       ARROW_BUILD_TESTS: ON
       ARROW_DATASET: ON
+      ARROW_FILESYSTEM: ON
       ARROW_FLIGHT: OFF
       ARROW_HDFS: ON
       ARROW_HOME: /usr

cpp/cmake_modules/ThirdpartyToolchain.cmake

@@ -595,6 +595,13 @@ else()
   )
 endif()
 
+if(DEFINED ENV{ARROW_WIL_URL})
+  set(ARROW_WIL_URL "$ENV{ARROW_WIL_URL}")
+else()
+  set_urls(ARROW_WIL_URL
+           "https://github.com/microsoft/wil/archive/${ARROW_WIL_BUILD_VERSION}.tar.gz")
+endif()
+
 if(DEFINED ENV{ARROW_BOOST_URL})
   set(BOOST_SOURCE_URL "$ENV{ARROW_BOOST_URL}")
 else()
@@ -4054,6 +4061,27 @@ endif()
 
 function(build_azure_sdk)
   message(STATUS "Building Azure SDK for C++ from source")
+
+  # On Windows, Azure SDK's WinHTTP transport requires WIL (Windows Implementation Libraries).
+  # Fetch WIL before Azure SDK so the WIL::WIL target is available.
+  if(WIN32)
+    message(STATUS "Fetching WIL (Windows Implementation Libraries) for Azure SDK")
+    fetchcontent_declare(wil
+                         ${FC_DECLARE_COMMON_OPTIONS}
+                         URL ${ARROW_WIL_URL}
+                         URL_HASH "SHA256=${ARROW_WIL_BUILD_SHA256_CHECKSUM}")
+    set(WIL_BUILD_PACKAGING OFF)
+    set(WIL_BUILD_TESTS OFF)
+    fetchcontent_makeavailable(wil)
+    # Create a minimal config file so Azure SDK's find_package(wil CONFIG) succeeds.
+    # The WIL::WIL target already exists from FetchContent above.
+    file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/wil-config/wilConfig.cmake"
+         "# WIL loaded via FetchContent - target WIL::WIL already exists\n")
+    set(wil_DIR
+        "${CMAKE_CURRENT_BINARY_DIR}/wil-config"
+        CACHE PATH "" FORCE)
+  endif()
+
   fetchcontent_declare(azure_sdk
                        ${FC_DECLARE_COMMON_OPTIONS}
                        URL ${ARROW_AZURE_SDK_URL}

cpp/src/arrow/filesystem/azurefs.cc

@@ -1363,6 +1363,7 @@ Result<HNSSupport> CheckIfHierarchicalNamespaceIsEnabled(
     directory_client.GetAccessControlList();
     return HNSSupport::kEnabled;
   } catch (std::out_of_range& exception) {
+    ARROW_UNUSED(exception);
     // Azurite issue detected.
     DCHECK(IsDfsEmulator(options));
     return HNSSupport::kDisabled;
@@ -2500,6 +2501,7 @@ class AzureFileSystem::Impl {
             auto delete_result = deferred_response.GetResponse();
             success = delete_result.Value.Deleted;
           } catch (const Core::RequestFailedException& exception) {
+            ARROW_UNUSED(exception);
             success = false;
           }
           if (!success) {
@@ -3218,6 +3220,11 @@ class AzureFileSystem::Impl {
 std::atomic<LeaseGuard::SteadyClock::time_point> LeaseGuard::latest_known_expiry_time_ =
     SteadyClock::time_point{SteadyClock::duration::zero()};
 
+// Destructor must be defined here where Impl is a complete type.
+// Defining it in the header (even as = default) causes MSVC to fail
+// because it tries to instantiate std::default_delete<Impl> before Impl is defined.
+AzureFileSystem::~AzureFileSystem() {}
+
 AzureFileSystem::AzureFileSystem(std::unique_ptr<Impl>&& impl)
     : FileSystem(impl->io_context()), impl_(std::move(impl)) {
   default_async_is_sync_ = false;

cpp/src/arrow/filesystem/azurefs.h

@@ -251,7 +251,9 @@ class ARROW_EXPORT AzureFileSystem : public FileSystem {
   void ForceCachedHierarchicalNamespaceSupport(int hns_support);
 
  public:
-  ~AzureFileSystem() override = default;
+  // Destructor must be defined in the .cc file where Impl is complete,
+  // otherwise MSVC fails with "use of undefined type" for std::unique_ptr<Impl>.
+  ~AzureFileSystem() override;
 
   static Result<std::shared_ptr<AzureFileSystem>> Make(
       const AzureOptions& options, const io::IOContext& = io::default_io_context());

cpp/thirdparty/versions.txt

@@ -56,6 +56,9 @@ ARROW_AWSSDK_BUILD_SHA256_CHECKSUM=b9944ba9905a68d6e53abb4f36ab2b3bd18ac88d85716
 # Despite the confusing version name this is still the whole Azure SDK for C++ including core, keyvault, storage-common, etc.
 ARROW_AZURE_SDK_BUILD_VERSION=azure-identity_1.9.0
 ARROW_AZURE_SDK_BUILD_SHA256_CHECKSUM=97065bfc971ac8df450853ce805f820f52b59457bd7556510186a1569502e4a1
+# WIL (Windows Implementation Libraries) is required by Azure SDK on Windows for WinHTTP transport
+ARROW_WIL_BUILD_VERSION=v1.0.250325.1
+ARROW_WIL_BUILD_SHA256_CHECKSUM=c9e667d5f86ded43d17b5669d243e95ca7b437e3a167c170805ffd4aa8a9a786
 ARROW_BOOST_BUILD_VERSION=1.88.0
 ARROW_BOOST_BUILD_SHA256_CHECKSUM=dcea50f40ba1ecfc448fdf886c0165cf3e525fef2c9e3e080b9804e8117b9694
 ARROW_BROTLI_BUILD_VERSION=v1.0.9