Treat external repositories as system headers for warning purposes.

.bazelrc

@@ -1,4 +1,4 @@
-# Copyright 2021, 2022, 2023 Google LLC
+# Copyright 2021, 2022, 2023, 2024 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -12,10 +12,21 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+common --enable_platform_specific_config
+
 # Run Pylint by default.
 build --aspects='//private:defs.bzl%check_python'
 build --output_groups='+check_python'
 
+# The external_include_paths feature has to be specified in .bazelrc because it
+# needs to apply to all compile actions in all repositories.
+# TODO: File bug against Bazel to make this work as repository-level feature.
+build --features=external_include_paths --host_features=external_include_paths
+
+# The next line shouldn’t be necessary.
+# TODO: File bug against Bazel.
+build:windows --copt=/external:W0
+
 import %workspace%/c-std.bazelrc
 
 try-import %workspace%/github.bazelrc

.github/actions/set-up/action.yaml

@@ -129,3 +129,14 @@ runs:
         startsWith(inputs.bazel-version, '6.3.') ||
         startsWith(inputs.bazel-version, '6.4.')
         )
+    - name: Remove unsupported options
+      shell: bash
+      # --host_features was introduced in Bazel 6.1.
+      run: |
+        set -efuC
+        for file in .bazelrc examples/ext/.bazelrc; do
+          sed -- 's/--host_features=[_[:alnum:]]*//g' "${file}" > "${file}.temp"
+          mv -- "${file}.temp" "${file}"
+        done
+      if: >-
+        startsWith(inputs.bazel-version, '6.0.')

elisp/binary.cc

@@ -16,24 +16,8 @@
 
 #include <initializer_list>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 #include "elisp/process.h"

elisp/emacs.cc

@@ -16,24 +16,8 @@
 
 #include <initializer_list>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 #include "elisp/process.h"

elisp/launcher.cc

@@ -14,28 +14,12 @@
 
 #include <cstdlib>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/container/fixed_array.h"
 #include "absl/log/log.h"
 #include "absl/meta/type_traits.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 #include "elisp/main.h"

elisp/main.h

@@ -21,24 +21,8 @@
 
 #include <initializer_list>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 

elisp/process.cc

@@ -52,16 +52,6 @@
 #include <utility>
 #include <vector>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/algorithm/container.h"
 #include "absl/base/attributes.h"
 #include "absl/base/nullability.h"
@@ -78,12 +68,6 @@
 #include "absl/strings/str_join.h"
 #include "absl/types/span.h"
 #include "tools/cpp/runfiles/runfiles.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #ifdef __APPLE__
 #  include <crt_externs.h>  // for _NSGetEnviron

elisp/process.h

@@ -22,24 +22,8 @@
 #include <initializer_list>
 #include <string_view>  // IWYU pragma: keep
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 

elisp/proto/module.c

@@ -131,15 +131,6 @@
 #  error Emacs module header too old
 #endif
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#  pragma warning(disable : 4090 4244 4267 4334)
-#endif
 #include "absl/base/attributes.h"
 #include "absl/base/config.h"
 #include "google/protobuf/any.upb.h"
@@ -165,12 +156,6 @@
 #include "upb/util/required_fields.h"
 #include "upb/wire/decode.h"
 #include "upb/wire/encode.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 /// Global variables
 

elisp/test.cc

@@ -16,24 +16,8 @@
 
 #include <initializer_list>
 
-#ifdef __GNUC__
-#  pragma GCC diagnostic push
-#  pragma GCC diagnostic ignored "-Wpedantic"
-#  pragma GCC diagnostic ignored "-Wconversion"
-#  pragma GCC diagnostic ignored "-Wsign-conversion"
-#  pragma GCC diagnostic ignored "-Woverflow"
-#endif
-#ifdef _MSC_VER
-#  pragma warning(push, 3)
-#endif
 #include "absl/status/statusor.h"
 #include "absl/types/span.h"
-#ifdef __GNUC__
-#  pragma GCC diagnostic pop
-#endif
-#ifdef _MSC_VER
-#  pragma warning(pop)
-#endif
 
 #include "elisp/platform.h"
 #include "elisp/process.h"

examples/ext/.bazelrc

@@ -12,6 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# The external_include_paths feature has to be specified in .bazelrc because it
+# needs to apply to all compile actions in all repositories.
+# TODO: File bug against Bazel to make this work as repository-level feature.
+build --features=external_include_paths --host_features=external_include_paths
+
 import %workspace%/../../c-std.bazelrc
 
 try-import %workspace%/../../github.bazelrc

private/defs.bzl

@@ -440,6 +440,15 @@ COPTS = select({
         "-pedantic",
         "-pedantic-errors",
     ],
+}) + select({
+    Label("//private:clang"): [
+        # This shouldn’t be needed, but the external_include_paths feature
+        # doesn’t work on macOS.
+        # TODO: File bug against Bazel.
+        "--system-header-prefix=absl/",
+        "--system-header-prefix=upb/",
+    ],
+    Label("//conditions:default"): [],
 })
 
 CXXOPTS = select({