fix

CMakeLists.txt

@@ -152,6 +152,7 @@ if (CMAKE_GENERATOR STREQUAL "Ninja" AND NOT DISABLE_COLORED_BUILD)
     set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-color=always")
 endif ()
 
+include (cmake/check_flags.cmake)
 include (cmake/add_warning.cmake)
 
 if (NOT MSVC)
@@ -166,7 +167,8 @@ if (COMPILER_CLANG)
         set(COMPILER_FLAGS "${COMPILER_FLAGS} -gdwarf-aranges")
     endif ()
 
-    if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0.0)
+    if (HAS_USE_CTOR_HOMING)
+        # For more 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")
@@ -192,7 +194,7 @@ endif ()
 # Make sure the final executable has symbols exported
 set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -rdynamic")
 
-find_program (OBJCOPY_PATH NAMES "llvm-objcopy" "llvm-objcopy-12" "llvm-objcopy-11" "llvm-objcopy-10" "llvm-objcopy-9" "llvm-objcopy-8" "objcopy")
+find_program (OBJCOPY_PATH NAMES "llvm-objcopy" "llvm-objcopy-13" "llvm-objcopy-12" "llvm-objcopy-11" "llvm-objcopy-10" "llvm-objcopy-9" "llvm-objcopy-8" "objcopy")
 
 if (NOT OBJCOPY_PATH AND OS_DARWIN)
     find_program (BREW_PATH NAMES "brew")
@@ -379,7 +381,7 @@ if (COMPILER_CLANG)
     endif ()
 
     # Always prefer llvm tools when using clang. For instance, we cannot use GNU ar when llvm LTO is enabled
-    find_program (LLVM_AR_PATH NAMES "llvm-ar" "llvm-ar-12" "llvm-ar-11" "llvm-ar-10" "llvm-ar-9" "llvm-ar-8")
+    find_program (LLVM_AR_PATH NAMES "llvm-ar" "llvm-ar-13" "llvm-ar-12" "llvm-ar-11" "llvm-ar-10" "llvm-ar-9" "llvm-ar-8")
 
     if (LLVM_AR_PATH)
         message(STATUS "Using llvm-ar: ${LLVM_AR_PATH}.")
@@ -388,7 +390,7 @@ if (COMPILER_CLANG)
         message(WARNING "Cannot find llvm-ar. System ar will be used instead. It does not work with ThinLTO.")
     endif ()
 
-    find_program (LLVM_RANLIB_PATH NAMES "llvm-ranlib" "llvm-ranlib-12" "llvm-ranlib-11" "llvm-ranlib-10" "llvm-ranlib-9" "llvm-ranlib-8")
+    find_program (LLVM_RANLIB_PATH NAMES "llvm-ranlib" "llvm-ranlib-13" "llvm-ranlib-12" "llvm-ranlib-11" "llvm-ranlib-10" "llvm-ranlib-9" "llvm-ranlib-8")
 
     if (LLVM_RANLIB_PATH)
         message(STATUS "Using llvm-ranlib: ${LLVM_RANLIB_PATH}.")
@@ -629,9 +631,6 @@ include_directories(${ConfigIncludePath})
 # Add as many warnings as possible for our own code.
 include (cmake/warnings.cmake)
 
-# Check if needed compiler flags are supported
-include (cmake/check_flags.cmake)
-
 add_subdirectory (base)
 add_subdirectory (src)
 add_subdirectory (programs)

base/common/CachedFn.h

@@ -5,13 +5,12 @@
 #include "FnTraits.h"
 
 /**
- * Cache for a functor that decays to a pointer-to-function.
- * The size is unlimited. Values are stored permanently and never evicted.
- * Suitable only for simplest cases.
- *
+ * Caching proxy for a functor that decays to a pointer-to-function.
+ * Saves pairs (func args, func result on args).
+ * Cache size is unlimited. Cache items are evicted only on manual drop.
  * Invocation/update is O(log(saved cache values)).
  *
- * @example CachedFn<&my_func> cached; cached(arg);
+ * See Common/tests/cached_fn.cpp for examples.
   */
 template <auto * Func>
 struct CachedFn

src/Common/examples/CMakeLists.txt

@@ -19,9 +19,6 @@ target_link_libraries (parallel_aggregation2 PRIVATE dbms)
 add_executable (int_hashes_perf int_hashes_perf.cpp)
 target_link_libraries (int_hashes_perf PRIVATE clickhouse_common_io)
 
-add_executable (simple_cache simple_cache.cpp)
-target_link_libraries (simple_cache PRIVATE common)
-
 add_executable (compact_array compact_array.cpp)
 target_link_libraries (compact_array PRIVATE clickhouse_common_io)
 

src/Common/examples/simple_cache.cpp

@@ -1,22 +0,0 @@
-#include <iostream>
-#include <common/CachedFn.h>
-
-
-static int func(int x, int y)
-{
-    std::cerr << x << " + " << y << "\n";
-    return x + y;
-}
-
-
-int main(int, char **)
-{
-    CachedFn<&func> func_cached;
-
-    std::cerr << func_cached(1, 2) << "\n";
-    std::cerr << func_cached(1, 2) << "\n";
-    std::cerr << func_cached(1, 2) << "\n";
-    std::cerr << func_cached(3, 4) << "\n";
-    std::cerr << func_cached(3, 4) << "\n";
-    std::cerr << func_cached(3, 4) << "\n";
-}

src/Common/tests/gtest_cached_fn.cpp

@@ -0,0 +1,50 @@
+#include <gtest/gtest.h>
+#include <thread>
+#include <chrono>
+#include <common/CachedFn.h>
+
+using namespace std::chrono_literals;
+
+constexpr int add(int x, int y)
+{
+    return x + y;
+}
+
+static int longFunction(int x, int y)
+{
+    std::this_thread::sleep_for(1s);
+    return x + y;
+}
+
+TEST(CachedFn, Basic)
+{
+    CachedFn<&add> fn;
+
+    const int res = fn(1, 2);
+    EXPECT_EQ(fn(1, 2), res);
+
+    auto f = [](int x, int y) { return x - y; };
+    CachedFn<+f> fn2;
+
+    const int res2 = fn2(1, 2);
+    EXPECT_EQ(fn2(1, 2), res2);
+}
+
+TEST(CachedFn, CachingResults)
+{
+    CachedFn<&longFunction> fn;
+
+    for (int x = 0; x < 2; ++x)
+    {
+        for (int y = 0; y < 2; ++y)
+        {
+            const int res = fn(x, y);
+            const time_t start = time(nullptr);
+
+            for (int count = 0; count < 1000; ++count)
+                EXPECT_EQ(fn(x, y), res);
+
+            EXPECT_LT(time(nullptr) - start, 10);
+        }
+    }
+}