Remove cruft from build

No need to check compiler flags, clang >= 15 supports all of them.

CMakeLists.txt

@@ -121,6 +121,7 @@ if (ENABLE_COLORED_BUILD AND CMAKE_GENERATOR STREQUAL "Ninja")
     set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-color=always")
     # ... such manually setting of flags can be removed once CMake supports a variable to
     # activate colors in *all* build systems: https://gitlab.kitware.com/cmake/cmake/-/issues/15502
+    # --> available since CMake 3.24: https://stackoverflow.com/a/73349744
 endif ()
 
 include (cmake/check_flags.cmake)
@@ -134,24 +135,15 @@ if (COMPILER_CLANG)
         set(COMPILER_FLAGS "${COMPILER_FLAGS} -gdwarf-aranges")
     endif ()
 
-    if (HAS_USE_CTOR_HOMING)
-        # For more info see https://blog.llvm.org/posts/2021-04-05-constructor-homing-for-debug-info/
+    # See https://blog.llvm.org/posts/2021-04-05-constructor-homing-for-debug-info/
     if (CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG" OR CMAKE_BUILD_TYPE_UC STREQUAL "RELWITHDEBINFO")
         set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Xclang -fuse-ctor-homing")
         set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Xclang -fuse-ctor-homing")
     endif()
-    endif()
 
     no_warning(enum-constexpr-conversion) # breaks Protobuf in clang-16
 endif ()
 
-# If compiler has support for -Wreserved-identifier. It is difficult to detect by clang version,
-# because there are two different branches of clang: clang and AppleClang.
-# (AppleClang is not supported by ClickHouse, but some developers have misfortune to use it).
-if (HAS_RESERVED_IDENTIFIER)
-    add_compile_definitions (HAS_RESERVED_IDENTIFIER)
-endif ()
-
 option(ENABLE_TESTS "Provide unit_test_dbms target with Google.Test unit tests" ON)
 option(ENABLE_EXAMPLES "Build all example programs in 'examples' subdirectories" OFF)
 option(ENABLE_BENCHMARKS "Build all benchmark programs in 'benchmarks' subdirectories" OFF)
@@ -311,6 +303,7 @@ set (CMAKE_C_STANDARD_REQUIRED ON)
 
 if (COMPILER_GCC OR COMPILER_CLANG)
     # Enable C++14 sized global deallocation functions. It should be enabled by setting -std=c++14 but I'm not sure.
+    # See https://reviews.llvm.org/D112921
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsized-deallocation")
 endif ()
 
@@ -329,12 +322,8 @@ if (ARCH_AMD64)
         set(BRANCHES_WITHIN_32B_BOUNDARIES "-Wa,${BRANCHES_WITHIN_32B_BOUNDARIES}")
     endif()
 
-    include(CheckCXXCompilerFlag)
-    check_cxx_compiler_flag("${BRANCHES_WITHIN_32B_BOUNDARIES}" HAS_BRANCHES_WITHIN_32B_BOUNDARIES)
-    if (HAS_BRANCHES_WITHIN_32B_BOUNDARIES)
     set(COMPILER_FLAGS "${COMPILER_FLAGS} ${BRANCHES_WITHIN_32B_BOUNDARIES}")
 endif()
-endif()
 
 if (COMPILER_GCC)
     set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fcoroutines")
@@ -445,6 +434,7 @@ option(WERROR "Enable -Werror compiler option" ON)
 if (WERROR)
     # Don't pollute CMAKE_CXX_FLAGS with -Werror as it will break some CMake checks.
     # Instead, adopt modern cmake usage requirement.
+    # TODO: Set CMAKE_COMPILE_WARNING_AS_ERROR (cmake 3.24)
     target_compile_options(global-group INTERFACE "-Werror")
 endif ()
 

base/base/phdr_cache.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 /// This code was based on the code by Fedor Korotkiy https://www.linkedin.com/in/fedor-korotkiy-659a1838/
 

base/base/unit.h

@@ -5,10 +5,8 @@ constexpr size_t KiB = 1024;
 constexpr size_t MiB = 1024 * KiB;
 constexpr size_t GiB = 1024 * MiB;
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 // NOLINTBEGIN(google-runtime-int)
 constexpr size_t operator"" _KiB(unsigned long long val) { return val * KiB; }
@@ -16,6 +14,4 @@ constexpr size_t operator"" _MiB(unsigned long long val) { return val * MiB; }
 constexpr size_t operator"" _GiB(unsigned long long val) { return val * GiB; }
 // NOLINTEND(google-runtime-int)
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic pop
-#endif

base/readpassphrase/readpassphrase.c

@@ -27,9 +27,7 @@
 #define _PATH_TTY "/dev/tty"
 #endif
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <termios.h>
 #include <signal.h>

cmake/check_flags.cmake

@@ -1,7 +1,5 @@
 include (CheckCXXCompilerFlag)
 include (CheckCCompilerFlag)
 
-check_cxx_compiler_flag("-Wreserved-identifier" HAS_RESERVED_IDENTIFIER)
-check_cxx_compiler_flag("-Wsuggest-destructor-override" HAS_SUGGEST_DESTRUCTOR_OVERRIDE)
-check_cxx_compiler_flag("-Wsuggest-override" HAS_SUGGEST_OVERRIDE)
-check_cxx_compiler_flag("-Xclang -fuse-ctor-homing" HAS_USE_CTOR_HOMING)
+# Set/unset variable based on existence of compiler flags. Example:
+# check_cxx_compiler_flag("-Wreserved-identifier" HAS_RESERVED_IDENTIFIER)

src/Client/LineReader.cpp

@@ -12,9 +12,7 @@
 #include <sys/types.h>
 
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 namespace
 {

src/Common/ThreadFuzzer.cpp

@@ -34,9 +34,7 @@
         M(int, pthread_mutex_unlock, pthread_mutex_t * arg)
 #endif
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 namespace DB
 {

src/Common/UTF8Helpers.h

@@ -11,10 +11,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 
 namespace DB

src/Common/examples/int_hashes_perf.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #if defined (OS_LINUX)
 #   include <sched.h>

src/Common/memcmpSmall.h

@@ -502,9 +502,7 @@ inline bool memoryIsZeroSmallAllowOverflow15(const void * data, size_t size)
 #elif defined(__aarch64__) && defined(__ARM_NEON)
 
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
-#    endif
 
 inline uint64_t getNibbleMask(uint8x16_t res)
 {

src/Common/memcpySmall.h

@@ -8,10 +8,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 /** memcpy function could work suboptimal if all the following conditions are met:
   * 1. Size of memory region is relatively small (approximately, under 50 bytes).

src/Compression/CompressionCodecDoubleDelta.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <Compression/ICompressionCodec.h>
 #include <Compression/CompressionInfo.h>

src/Compression/CompressionCodecGorilla.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <Compression/ICompressionCodec.h>
 #include <Compression/CompressionInfo.h>

src/Daemon/BaseDaemon.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <Daemon/BaseDaemon.h>
 #include <Daemon/SentryWriter.h>

src/Functions/FunctionsCodingIP.cpp

@@ -1,7 +1,5 @@
 #include <functional>
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <Functions/FunctionsCodingIP.h>
 

src/Functions/GatherUtils/CMakeLists.txt

@@ -4,14 +4,6 @@ add_headers_and_sources(clickhouse_functions_gatherutils .)
 add_library(clickhouse_functions_gatherutils ${clickhouse_functions_gatherutils_sources} ${clickhouse_functions_gatherutils_headers})
 target_link_libraries(clickhouse_functions_gatherutils PRIVATE dbms)
 
-if (HAS_SUGGEST_OVERRIDE)
-    target_compile_definitions(clickhouse_functions_gatherutils PUBLIC HAS_SUGGEST_OVERRIDE)
-endif()
-
-if (HAS_SUGGEST_DESTRUCTOR_OVERRIDE)
-    target_compile_definitions(clickhouse_functions_gatherutils PUBLIC HAS_SUGGEST_DESTRUCTOR_OVERRIDE)
-endif()
-
 if (OMIT_HEAVY_DEBUG_SYMBOLS)
     target_compile_options(clickhouse_functions_gatherutils PRIVATE "-g0")
 endif()

src/Functions/GatherUtils/Sources.h

@@ -141,12 +141,8 @@ struct NumericArraySource : public ArraySourceImpl<NumericArraySource<T>>
 
 /// The methods can be virtual or not depending on the template parameter. See IStringSource.
 #pragma GCC diagnostic push
-#ifdef HAS_SUGGEST_OVERRIDE
 #pragma GCC diagnostic ignored "-Wsuggest-override"
-#endif
-#ifdef HAS_SUGGEST_DESTRUCTOR_OVERRIDE
 #pragma GCC diagnostic ignored "-Wsuggest-destructor-override"
-#endif
 
 template <typename Base>
 struct ConstSource : public Base

src/Functions/toValidUTF8.cpp

@@ -13,10 +13,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 namespace DB
 {

src/IO/ReadBufferFromFileDescriptor.cpp

@@ -12,9 +12,7 @@
 #include <Interpreters/Context.h>
 
 
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 namespace ProfileEvents
 {

src/IO/ReadHelpers.cpp

@@ -18,10 +18,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 namespace DB
 {

src/IO/WriteBufferValidUTF8.cpp

@@ -8,10 +8,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 namespace DB
 {

src/IO/tests/gtest_bit_io.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <cstring>
 #include <IO/BitHelpers.h>

src/Processors/Formats/Impl/ArrowBufferedStreams.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include "ArrowBufferedStreams.h"
 

src/Storages/MergeTree/MergeTreeRangeReader.cpp

@@ -18,10 +18,8 @@
 
 #if defined(__aarch64__) && defined(__ARM_NEON)
 #    include <arm_neon.h>
-#    ifdef HAS_RESERVED_IDENTIFIER
 #      pragma clang diagnostic ignored "-Wreserved-identifier"
 #endif
-#endif
 
 namespace DB
 {

utils/memcpy-bench/memcpy-bench.cpp

@@ -1,6 +1,4 @@
-#ifdef HAS_RESERVED_IDENTIFIER
 #pragma clang diagnostic ignored "-Wreserved-identifier"
-#endif
 
 #include <memory>
 #include <cstddef>