Merge pull request #30012 from redpanda-data/stephan/clang-22-default

bazel: Switch over to clang-22

Author: StephanDollberg

.bazelrc

@@ -6,11 +6,6 @@ common --@toolchains_llvm//toolchain/config:compiler-rt=False
 build --linkopt --unwindlib=libgcc
 build --linkopt -stdlib=libc++
 
-common:clang-21 --extra_toolchains=@next_llvm_toolchain//:all
-
-# llvm 22.1.0
-common:clang-22 --extra_toolchains=@clang-22_llvm_toolchain//:all
-
 # Use Bash instead of system python for finding the hermetic interpreter
 # within Bazel due to the `python3` binary not being present on CI
 # (it has `python` version 3 but Bazel uses the `python3` executable).
@@ -31,13 +26,6 @@ build:system-clang --extra_toolchains=@local_config_cc_toolchains//:all
 build:system-clang --action_env=BAZEL_COMPILER=clang
 build:system-clang --cxxopt=-std=c++23 --host_cxxopt=-std=c++23
 build:system-clang --linkopt -fuse-ld=lld
-# use a compiler name that doesn't symlink to ccache
-build:system-clang-19 --config=system-clang
-build:system-clang-19 --action_env=CC=clang-19 --host_action_env=CC=clang-19
-build:system-clang-19 --action_env=CXX=clang++-19 --host_action_env=CXX=clang++-19
-build:system-clang-20 --config=system-clang
-build:system-clang-20 --action_env=CC=clang-20 --host_action_env=CC=clang-20
-build:system-clang-20 --action_env=CXX=clang++-20 --host_action_env=CXX=clang++-20
 
 # Use new proto toolchain resolution
 build --incompatible_enable_proto_toolchain_resolution

.clang-tidy

@@ -1,7 +1,8 @@
 ---
 Checks:          'redpanda-*,clang-diagnostic-*,clang-analyzer-*,cert-*,cppcoreguidelines-*,hicpp-*,modernize-*,performance-*,misc-*,bugprone-*,-modernize-use-trailing-return-type,-modernize-use-nodiscard,-hicpp-named-parameter,-misc-include-cleaner,-clang-analyzer-optin.core.EnumCastOutOfRange,-cppcoreguidelines-avoid-reference-coroutine-parameters'
 WarningsAsErrors: 'redpanda-*,bugprone-use-after-move,bugprone-assert-side-effect,bugprone-assignment-in-if-condition,bugprone-dangling-handle,bugprone-sizeof-container,bugprone-stringview-nullptr,bugprone-unused-return-value,bugprone-suspicious-string-compare,misc-unused-using-decls,misc-unused-alias-decls,modernize-redundant-void-arg,performance-implicit-conversion-in-loop,performance-trivially-destructible,performance-no-automatic-move,performance-move-const-arg,bugprone-unused-local-non-trivial-variable'
-HeaderFilterRegex: '^(?!external/.*).*'
+HeaderFilterRegex: '.*'
+ExcludeHeaderFilterRegex: '(^|/)external/|\.json\.hh$'
 FormatStyle:    file
 CheckOptions:
   - key:             cert-dcl16-c.NewSuffixes

.git-blame-ignore-revs

@@ -21,4 +21,7 @@ b079582532df982b81190a34fd0b1f9621ba8213
 e3c23b96330a88fba88b6f1bd4f1fa68086e53fb
 
 # ruff check . --select F401 --fix
-77f53ca22fb2ed2fe6cfba40ca6923928e8d8988
+77f53ca22fb2ed2fe6cfba40ca6923928e8d8988
+
+# upgraded to clang-format 22
+efb217101ea58381443956ce0e9da3678857135c

MODULE.bazel

@@ -157,32 +157,6 @@ COMPILE_FLAGS = {
 
 COMPILERS = {
     "current": {
-        "tars": {
-            "aarch64": {
-                "build_date": "2025-11-14",
-                "sha": "f51afb38ca39cc93c6ed065a0c463d3587b975204d6028a63de33153caf3e104",
-            },
-            "x86_64": {
-                "build_date": "2025-11-14",
-                "sha": "616e3f50b1f03b61ec712f4f28fa67668d60ae3edccea8508065a3f49dbbb24a",
-            },
-        },
-        "version": "20.1.8",
-    },
-    "next": {
-        "tars": {
-            "aarch64": {
-                "build_date": "2025-11-25",
-                "sha": "37257804087a26b0ede7c0349d3f44db7b7439e551fc6c753f7934ead654c1b8",
-            },
-            "x86_64": {
-                "build_date": "2025-11-25",
-                "sha": "b3aa9cb72c2e46bd1cc3f17f3772b37a424e54f796253961382163eab2f4a9c0",
-            },
-        },
-        "version": "21.1.6",
-    },
-    "clang-22": {
         "tars": {
             "aarch64": {
                 "build_date": "2026-03-02",

MODULE.bazel.lock

@@ -192,6 +192,7 @@ def deps_flags(deps):
     ])
 
     flags = []
+
     for compilation_context in compilation_contexts:
         # add defines
         for define in compilation_context.defines.to_list():
@@ -266,8 +267,7 @@ def _clang_tidy_aspect_impl(target, ctx):
     c_flags = toolchain_flags(ctx, ACTION_NAMES.c_compile) + rule_flags + ["-xc"]
     cxx_flags = toolchain_flags(ctx, ACTION_NAMES.cpp_compile) + rule_flags + ["-xc++"]
 
-    include_headers = "no-clang-tidy-headers" not in ctx.rule.attr.tags
-    srcs = rule_sources(ctx.rule.attr, include_headers)
+    srcs = rule_sources(ctx.rule.attr, False)
 
     outputs = [
         _run_tidy(

bazel/clang_tidy/clang_tidy.bzl

@@ -30,6 +30,11 @@ def main():
     yaml.safe_dump(config, final_config_file.file)
 
     try:
+        extra_args = [
+            "--extra-arg=-Wno-error",
+            "--extra-arg=-Wno-macro-redefined",
+        ]
+
         verify_command = [
             clang_tidy_bin,
             f"--config-file={final_config_file.name}",
@@ -39,11 +44,15 @@ def main():
         ]
         _ = subprocess.run(verify_command, check=True, capture_output=True, text=True)
 
-        run_command = [
-            clang_tidy_bin,
-            f"--config-file={final_config_file.name}",
-            f"--load={plugins_lib}",
-        ] + remaining_args
+        run_command = (
+            [
+                clang_tidy_bin,
+                f"--config-file={final_config_file.name}",
+                f"--load={plugins_lib}",
+            ]
+            + extra_args
+            + remaining_args
+        )
 
         _ = subprocess.run(run_command, check=True, capture_output=True, text=True)
 

bazel/clang_tidy/clang_tidy.py

@@ -11,7 +11,6 @@
 #include "redpanda_noop_check.h"
 
 #include <clang-tidy/ClangTidyModule.h>
-#include <clang-tidy/ClangTidyModuleRegistry.h>
 
 namespace clang::tidy {
 

bazel/clang_tidy/plugins/redpanda_tidy_module.cc

@@ -41,11 +41,12 @@ constexpr std::string_view schema_def = R"({
 
 int main() {
     sr_client = sr::new_client();
-    if (auto res = sr_client->create_schema(
-          "avro-value",
-          sr::schema::new_avro(
-            std::string{schema_def.data(), schema_def.size()}));
-        !res.has_value()) {
+    if (
+      auto res = sr_client->create_schema(
+        "avro-value",
+        sr::schema::new_avro(
+          std::string{schema_def.data(), schema_def.size()}));
+      !res.has_value()) {
         return 0;
     }
     redpanda::on_record_written(do_transform);
@@ -67,8 +68,9 @@ do_transform(redpanda::write_event event, redpanda::record_writer* writer) {
         return id_e.error();
     }
     std::optional<sr::schema> raw_schema;
-    if (auto rs_e = sr_client->lookup_schema_by_id(id.value());
-        rs_e.has_value()) {
+    if (
+      auto rs_e = sr_client->lookup_schema_by_id(id.value());
+      rs_e.has_value()) {
         raw_schema.emplace(std::move(rs_e).value());
     } else {
         return rs_e.error();
@@ -77,17 +79,19 @@ do_transform(redpanda::write_event event, redpanda::record_writer* writer) {
     // auto schema = avro::schema::parse_str(raw_schema.value().schema());
 
     std::optional<sr::subject_schema> latest_schema;
-    if (auto latest_e = sr_client->lookup_latest_schema("avro-value");
-        latest_e.has_value()) {
+    if (
+      auto latest_e = sr_client->lookup_latest_schema("avro-value");
+      latest_e.has_value()) {
         latest_schema.emplace(std::move(latest_e).value());
     } else {
         return latest_e.error();
     }
 
     std::optional<sr::subject_schema> latest_direct;
-    if (auto latest_e = sr_client->lookup_schema_by_version(
-          "avro-value", latest_schema->version);
-        latest_e.has_value()) {
+    if (
+      auto latest_e = sr_client->lookup_schema_by_version(
+        "avro-value", latest_schema->version);
+      latest_e.has_value()) {
         latest_direct.emplace(std::move(latest_e).value());
     } else {
         return latest_e.error();