bazel: use expand_template instead of genrules

This lets us drop the dependency on the preprocessed headers in
src/windows/glog/.

For some reason, this lets Bazel realize we've failed to declare a
dependency on dirent.h, so I added that too.

bazel/glog.bzl

@@ -9,6 +9,28 @@
 #
 # Known issue: the namespace parameter is not supported on Win32.
 
+def expand_template_impl(ctx):
+    ctx.actions.expand_template(
+        template = ctx.file.template,
+        output = ctx.outputs.out,
+        substitutions = ctx.attr.substitutions,
+    )
+
+expand_template = rule(
+    implementation = expand_template_impl,
+    attrs = {
+        "template": attr.label(mandatory = True, allow_single_file = True),
+        "substitutions": attr.string_dict(mandatory = True),
+        "out": attr.output(mandatory = True),
+    },
+)
+
+def dict_union(x, y):
+  z = {}
+  z.update(x)
+  z.update(y)
+  return z
+
 def glog_library(namespace = "google", with_gflags = 1, **kwargs):
     if native.repository_name() != "@":
         repo_name = native.repository_name().lstrip("@")
@@ -78,6 +100,7 @@ def glog_library(namespace = "google", with_gflags = 1, **kwargs):
     windows_only_srcs = [
         "src/glog/log_severity.h",
         "src/windows/config.h",
+        "src/windows/dirent.h",
         "src/windows/port.cc",
         "src/windows/port.h",
     ]
@@ -112,29 +135,17 @@ def glog_library(namespace = "google", with_gflags = 1, **kwargs):
             "@bazel_tools//src/conditions:windows": windows_only_srcs,
             "//conditions:default": [":config_h"],
         }),
-        hdrs = select({
+        hdrs = [
-            "@bazel_tools//src/conditions:windows": [
-                "src/windows/glog/logging.h",
-                "src/windows/glog/log_severity.h",
-                "src/windows/glog/raw_logging.h",
-                "src/windows/glog/stl_logging.h",
-                "src/windows/glog/vlog_is_on.h",
-            ],
-            "//conditions:default": [
                 "src/glog/log_severity.h",
                 ":logging_h",
                 ":raw_logging_h",
                 ":stl_logging_h",
                 ":vlog_is_on_h",
             ],
-        }),
+        strip_include_prefix = "src",
-        strip_include_prefix = select({
-            "@bazel_tools//src/conditions:windows": "/src/windows",
-            "//conditions:default": "src",
-        }),
         defines = select({
             # We need to override the default GOOGLE_GLOG_DLL_DECL from
-            # src/windows/glog/*.h to match src/windows/config.h.
+            # src/glog/*.h to match src/windows/config.h.
             "@bazel_tools//src/conditions:windows": ["GOOGLE_GLOG_DLL_DECL=__declspec(dllexport)"],
             "//conditions:default": [],
         }),
@@ -157,57 +168,67 @@ def glog_library(namespace = "google", with_gflags = 1, **kwargs):
     # the dependencies without strip_include_prefix.
     native.cc_library(
         name = "strip_include_prefix_hack",
-        hdrs = native.glob(["src/windows/*.h"]),
+        hdrs = [
+            "src/glog/log_severity.h",
+            ":logging_h",
+            ":raw_logging_h",
+            ":stl_logging_h",
+            ":vlog_is_on_h",
+        ],
     )
 
-    native.genrule(
+    expand_template(
         name = "config_h",
-        srcs = [
+        template = "src/config.h.cmake.in",
-            "src/config.h.cmake.in",
+        out = "glog_internal/config.h",
-        ],
+        substitutions = {"#cmakedefine": "//cmakedefine"},
-        outs = [
-            "glog_internal/config.h",
-        ],
-        cmd = "awk '{ gsub(/^#cmakedefine/, \"//cmakedefine\"); print; }' $< > $@",
     )
 
-    native.genrule(
+    common_config = {
-        name = "gen_sh",
+        "@ac_cv_cxx_using_operator@": "1",
-        outs = [
+        "@ac_cv_have_inttypes_h@": "0",
-            "gen.sh",
+        "@ac_cv_have_u_int16_t@": "0",
-        ],
+        "@ac_cv_have_glog_export@": "0",
-        cmd = r'''\
+        "@ac_google_start_namespace@": "namespace google {",
-#!/bin/sh
+        "@ac_google_end_namespace@": "}",
-cat > $@ <<"EOF"
+        "@ac_google_namespace@": "google",
-sed -e 's/@ac_cv_cxx_using_operator@/1/g' \
+    }
-    -e 's/@ac_cv_have_unistd_h@/1/g' \
+
-    -e 's/@ac_cv_have_stdint_h@/1/g' \
+    posix_config = dict_union(common_config, {
-    -e 's/@ac_cv_have_systypes_h@/1/g' \
+        "@ac_cv_have_unistd_h@": "1",
-    -e 's/@ac_cv_have_libgflags@/{}/g' \
+        "@ac_cv_have_stdint_h@": "1",
-    -e 's/@ac_cv_have_uint16_t@/1/g' \
+        "@ac_cv_have_systypes_h@": "1",
-    -e 's/@ac_cv_have___builtin_expect@/1/g' \
+        "@ac_cv_have_uint16_t@": "1",
-    -e 's/@ac_cv_have_.*@/0/g' \
+        "@ac_cv_have___uint16@": "0",
-    -e 's/@ac_google_start_namespace@/namespace google {{/g' \
+        "@ac_cv_have___builtin_expect@": "1",
-    -e 's/@ac_google_end_namespace@/}}/g' \
+        "@ac_cv_have_libgflags@": "1" if with_gflags else "0",
-    -e 's/@ac_google_namespace@/google/g' \
+        "@ac_cv___attribute___noinline@": "__attribute__((noinline))",
-    -e 's/@ac_cv___attribute___noinline@/__attribute__((noinline))/g' \
+        "@ac_cv___attribute___noreturn@": "__attribute__((noreturn))",
-    -e 's/@ac_cv___attribute___noreturn@/__attribute__((noreturn))/g' \
+        "@ac_cv___attribute___printf_4_5@": "__attribute__((__format__(__printf__, 4, 5)))",
-    -e 's/@ac_cv___attribute___printf_4_5@/__attribute__((__format__(__printf__, 4, 5)))/g'
+    })
-EOF
+
-'''.format(int(with_gflags)),
+    windows_config = dict_union(common_config, {
-    )
+        "@ac_cv_have_unistd_h@": "0",
+        "@ac_cv_have_stdint_h@": "0",
+        "@ac_cv_have_systypes_h@": "0",
+        "@ac_cv_have_uint16_t@": "0",
+        "@ac_cv_have___uint16@": "1",
+        "@ac_cv_have___builtin_expect@": "0",
+        "@ac_cv_have_libgflags@": "0",
+        "@ac_cv___attribute___noinline@": "",
+        "@ac_cv___attribute___noreturn@": "__declspec(noreturn)",
+        "@ac_cv___attribute___printf_4_5@": "",
+    })
 
     [
-        native.genrule(
+        expand_template(
             name = "%s_h" % f,
-            srcs = [
+            template = "src/glog/%s.h.in" % f,
-                "src/glog/%s.h.in" % f,
+            out = "src/glog/%s.h" % f,
-            ],
+            substitutions = select({
-            outs = [
+                "@bazel_tools//src/conditions:windows": windows_config,
-                "src/glog/%s.h" % f,
+                "//conditions:default": posix_config,
-            ],
+            }),
-            cmd = "$(location :gen_sh) < $< > $@",
-            tools = [":gen_sh"],
         )
         for f in [
             "vlog_is_on",