[llvm-branch-commits] [llvm] release/22.x: [Benchmark] Fix warnings around usage of __COUNTER__ (#184524) (PR #184785)

[via llvm-branch-commits]

https://github.com/dyung created https://github.com/llvm/llvm-project/pull/184785

Backport 7fb92cdf5fa69423b4b99259057eb8de813c1344

Requested by: @dyung 

Fixes: #184740 

>From 89414fa8a0330f499e3ae406cb99bebf65733818 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Tue, 3 Mar 2026 17:39:16 -0800
Subject: [PATCH] [Benchmark] Fix warnings around usage of __COUNTER__
 (#184524)

Premerge CI is currently failing with the following after the update to
clang v22:

```
/home/gha/llvm-project/clang-tools-extra/clangd/benchmarks/IndexBenchmark.cpp:92:1: error: '__COUNTER__' is a C2y extension [-Werror,-Wc2y-extensions]
   92 | BENCHMARK(dexQueries);
      | ^
```

Some original work was done around this in
df1d786c460e0e47c9074f3533f098190ebfbc1b, which was then done in
upstream Google benchmark in

https://github.com/google/benchmark/commit/d8db2f90b643eb28a12976beb4d57bcfb639911d.
The original work done in the patch implementing this feature doesn't
seem to account for as many cases as the upstream patch does. This patch
reverts the diff in df1d786c460e0e47c9074f3533f098190ebfbc1b and applies
the applicable hunks from the upstream patch.
---
 .../benchmark/include/benchmark/benchmark.h   | 28 +++++++++++--------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/third-party/benchmark/include/benchmark/benchmark.h b/third-party/benchmark/include/benchmark/benchmark.h
index c2debb216d64f..71399d030a846 100644
--- a/third-party/benchmark/include/benchmark/benchmark.h
+++ b/third-party/benchmark/include/benchmark/benchmark.h
@@ -250,10 +250,6 @@ BENCHMARK(BM_test)->Unit(benchmark::kMillisecond);
   _Pragma("GCC diagnostic push")             \
   _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
 #define BENCHMARK_RESTORE_DEPRECATED_WARNING _Pragma("GCC diagnostic pop")
-#define BENCHMARK_DISABLE_PEDANTIC_WARNING \
-  _Pragma("GCC diagnostic push")             \
-  _Pragma("GCC diagnostic ignored \"-Wpedantic\"")
-#define BENCHMARK_RESTORE_PEDANTIC_WARNING _Pragma("GCC diagnostic pop")
 #elif defined(__NVCOMPILER)
 #define BENCHMARK_BUILTIN_EXPECT(x, y) __builtin_expect(x, y)
 #define BENCHMARK_DEPRECATED_MSG(msg) __attribute__((deprecated(msg)))
@@ -261,8 +257,6 @@ BENCHMARK(BM_test)->Unit(benchmark::kMillisecond);
   _Pragma("diagnostic push") \
   _Pragma("diag_suppress deprecated_entity_with_custom_message")
 #define BENCHMARK_RESTORE_DEPRECATED_WARNING _Pragma("diagnostic pop")
-#define BENCHMARK_DISABLE_PEDANTIC_WARNING
-#define BENCHMARK_RESTORE_PEDANTIC_WARNING
 #else
 #define BENCHMARK_BUILTIN_EXPECT(x, y) x
 #define BENCHMARK_DEPRECATED_MSG(msg)
@@ -271,8 +265,6 @@ BENCHMARK(BM_test)->Unit(benchmark::kMillisecond);
       __LINE__) ") : warning note: " msg))
 #define BENCHMARK_DISABLE_DEPRECATED_WARNING
 #define BENCHMARK_RESTORE_DEPRECATED_WARNING
-#define BENCHMARK_DISABLE_PEDANTIC_WARNING
-#define BENCHMARK_RESTORE_PEDANTIC_WARNING
 #endif
 // clang-format on
 
@@ -1467,16 +1459,29 @@ class Fixture : public internal::Benchmark {
 // ------------------------------------------------------
 // Macro to register benchmarks
 
+// clang-format off
+#if defined(__clang__)
+#define BENCHMARK_DISABLE_COUNTER_WARNING                        \
+  _Pragma("GCC diagnostic push")                                 \
+  _Pragma("GCC diagnostic ignored \"-Wunknown-warning-option\"") \
+  _Pragma("GCC diagnostic ignored \"-Wc2y-extensions\"")
+#define BENCHMARK_RESTORE_COUNTER_WARNING _Pragma("GCC diagnostic pop")
+#else
+#define BENCHMARK_DISABLE_COUNTER_WARNING
+#define BENCHMARK_RESTORE_COUNTER_WARNING
+#endif
+// clang-format on
+
 // Check that __COUNTER__ is defined and that __COUNTER__ increases by 1
 // every time it is expanded. X + 1 == X + 0 is used in case X is defined to be
 // empty. If X is empty the expression becomes (+1 == +0).
-BENCHMARK_DISABLE_PEDANTIC_WARNING
+BENCHMARK_DISABLE_COUNTER_WARNING
 #if defined(__COUNTER__) && (__COUNTER__ + 1 == __COUNTER__ + 0)
 #define BENCHMARK_PRIVATE_UNIQUE_ID __COUNTER__
 #else
 #define BENCHMARK_PRIVATE_UNIQUE_ID __LINE__
 #endif
-BENCHMARK_RESTORE_PEDANTIC_WARNING
+BENCHMARK_RESTORE_COUNTER_WARNING
 
 // Helpers for generating unique variable names
 #ifdef BENCHMARK_HAS_CXX11
@@ -1495,8 +1500,9 @@ BENCHMARK_RESTORE_PEDANTIC_WARNING
   BaseClass##_##Method##_Benchmark
 
 #define BENCHMARK_PRIVATE_DECLARE(n)                                 \
+  BENCHMARK_DISABLE_COUNTER_WARNING                                  \
   static ::benchmark::internal::Benchmark* BENCHMARK_PRIVATE_NAME(n) \
-      BENCHMARK_UNUSED
+      BENCHMARK_RESTORE_COUNTER_WARNING BENCHMARK_UNUSED
 
 #ifdef BENCHMARK_HAS_CXX11
 #define BENCHMARK(...)                                               \