Add ability to specify DLL dir (#939)

examples/cmake_hello_world_lib/shared/BUILD.bazel

@@ -18,17 +18,15 @@ cmake(
         "CMAKE_MACOSX_RPATH": "True",
     },
     lib_source = ":srcs",
+    out_interface_libs = select({
+        "//:windows": ["libhello.lib"],
+        "//conditions:default": [],
+    }),
     out_shared_libs = select({
         "//:macos": ["libhello.dylib"],
         "//:windows": ["libhello.dll"],
         "//conditions:default": ["libhello.so"],
     }),
-    # TODO: The `.dll` is installed in the `bin` directory. To account for this, windows
-    # moves it to the `lib` directory. The rules should account for this case.
-    postfix_script = select({
-        "//:windows": "cp -p $$INSTALLDIR$$/bin/libhello.dll $$INSTALLDIR$$/lib",
-        "//conditions:default": None,
-    }),
 )
 
 cc_test(

examples/cmake_hello_world_lib/shared/CMakeLists.txt

@@ -3,6 +3,8 @@
 
 cmake_minimum_required(VERSION 2.8.4)
 
+set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+
 project(hellolib LANGUAGES C)
 
 add_subdirectory(src)

foreign_cc/private/framework.bzl

@@ -151,6 +151,11 @@ CC_EXTERNAL_RULE_ATTRIBUTES = {
         doc = "Optional names of additional directories created by the build that should be declared as bazel action outputs",
         mandatory = False,
     ),
+    "out_dll_dir": attr.string(
+        doc = "Optional name of the output subdirectory with the dll files, defaults to 'bin'.",
+        mandatory = False,
+        default = "bin",
+    ),
     "out_headers_only": attr.bool(
         doc = "Flag variable to indicate that the library produces only headers",
         mandatory = False,
@@ -502,6 +507,7 @@ def cc_external_rule_impl(ctx, attrs):
     externally_built = ForeignCcArtifactInfo(
         gen_dir = installdir_copy.file,
         bin_dir_name = attrs.out_bin_dir,
+        dll_dir_name = attrs.out_dll_dir,
         lib_dir_name = attrs.out_lib_dir,
         include_dir_name = attrs.out_include_dir,
     )
@@ -741,7 +747,7 @@ def _define_outputs(ctx, attrs, lib_name):
 
     libraries = LibrariesToLinkInfo(
         static_libraries = _declare_out(ctx, lib_name, attrs.out_lib_dir, static_libraries),
-        shared_libraries = _declare_out(ctx, lib_name, attrs.out_lib_dir, attr_shared_libs),
+        shared_libraries = _declare_out(ctx, lib_name, attrs.out_dll_dir if targets_windows(ctx, None) else attrs.out_lib_dir, attr_shared_libs),
         interface_libraries = _declare_out(ctx, lib_name, attrs.out_lib_dir, attr_interface_libs),
     )
 

foreign_cc/providers.bzl

@@ -17,6 +17,7 @@ Can not be used as a top-level provider.
 Instances of ForeignCcArtifactInfo are encapsulated in a depset [ForeignCcDepsInfo::artifacts](#ForeignCcDepsInfo-artifacts).""",
     fields = {
         "bin_dir_name": "Bin directory, relative to install directory",
+        "dll_dir_name": "DLL directory, relative to install directory",
         "gen_dir": "Install directory",
         "include_dir_name": "Include directory, relative to install directory",
         "lib_dir_name": "Lib directory, relative to install directory",