Merge branch 'master' of github.com:google/benchmark into v2

.gitignore

@@ -44,3 +44,7 @@ rules.ninja
 # out-of-source build top-level folders.
 build/
 _build/
+
+# in-source dependancies
+/googletest/
+

.travis.yml

@@ -157,7 +157,7 @@ install:
     fi
 
 script:
-  - cmake -DCMAKE_C_COMPILER=${C_COMPILER} -DCMAKE_CXX_COMPILER=${COMPILER} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DCMAKE_CXX_FLAGS="${EXTRA_FLAGS}" -DBENCHMARK_BUILD_32_BITS=${BUILD_32_BITS} ..
+  - cmake -DCMAKE_C_COMPILER=${C_COMPILER} -DCMAKE_CXX_COMPILER=${COMPILER} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DCMAKE_CXX_FLAGS="${EXTRA_FLAGS}" -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON -DBENCHMARK_BUILD_32_BITS=${BUILD_32_BITS} ..
   - make
   - ctest -C ${BUILD_TYPE} --output-on-failure
 

CMakeLists.txt

@@ -5,6 +5,7 @@ project (benchmark)
 foreach(p
     CMP0054 # CMake 3.1
     CMP0056 # export EXE_LINKER_FLAGS to try_run
+    CMP0057 # Support no if() IN_LIST operator
     )
   if(POLICY ${p})
     cmake_policy(SET ${p} NEW)
@@ -18,6 +19,14 @@ option(BENCHMARK_USE_LIBCXX "Build and test using libc++ as the standard library
 option(BENCHMARK_BUILD_32_BITS "Build a 32 bit version of the library." OFF)
 option(BENCHMARK_ENABLE_INSTALL "Enable installation of benchmark. (Projects embedding benchmark may want to turn this OFF.)" ON)
 
+# Allow unmet dependencies to be met using CMake's ExternalProject mechanics, which
+# may require downloading the source code.
+option(BENCHMARK_DOWNLOAD_DEPENDENCIES "Allow the downloading and in-tree building of unmet dependencies" OFF)
+
+# This option can be used to disable building and running unit tests which depend on gtest
+# in cases where it is not possible to build or find a valid version of gtest.
+option(BENCHMARK_ENABLE_GTEST_TESTS "Enable building the unit tests which depend on gtest" ON)
+
 # Make sure we can import out CMake functions
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
@@ -97,9 +106,7 @@ else()
   if (NOT BENCHMARK_ENABLE_EXCEPTIONS)
     add_cxx_compiler_flag(-fno-exceptions)
   endif()
-  if (NOT BENCHMARK_USE_LIBCXX)
-    add_cxx_compiler_flag(-Wzero-as-null-pointer-constant)
-  endif()
+
   if (HAVE_CXX_FLAG_FSTRICT_ALIASING)
     if (NOT CMAKE_CXX_COMPILER_ID STREQUAL "Intel") #ICC17u2: Many false positives for Wstrict-aliasing
       add_cxx_compiler_flag(-Wstrict-aliasing)
@@ -199,5 +206,8 @@ add_subdirectory(src)
 
 if (BENCHMARK_ENABLE_TESTING)
   enable_testing()
+  if (BENCHMARK_ENABLE_GTEST_TESTS)
+    include(HandleGTest)
+  endif()
   add_subdirectory(test)
 endif()

README.md

@@ -14,6 +14,31 @@ IRC channel: https://freenode.net #googlebenchmark
 [Additional Tooling Documentation](docs/tools.md)
 
 
+## Building
+
+The basic steps for configuring and building the library look like this:
+
+```bash
+$ git clone https://github.com/google/benchmark.git
+# Benchmark requires GTest as a dependency. Add the source tree as a subdirectory.
+$ git clone https://github.com/google/googletest.git benchmark/googletest
+$ mkdir build && cd build
+$ cmake -G <generator> [options] ../benchmark
+# Assuming a makefile generator was used
+$ make
+```
+
+Note that Google Benchmark requires GTest to build and run the tests. This
+dependency can be provided three ways:
+
+* Checkout the GTest sources into `benchmark/googletest`.
+* Otherwise, if `-DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON` is specified during
+  configuration, the library will automatically download and build any required
+  dependencies.
+* Otherwise, if nothing is done, CMake will use `find_package(GTest REQUIRED)`
+  to resolve the required GTest dependency.
+
+
 ## Installation Guide
 
 For Ubuntu and Debian Based System

appveyor.yml

@@ -43,7 +43,7 @@ build_script:
   - md _build -Force
   - cd _build
   - echo %configuration%
-  - cmake -G "%generator%" "-DCMAKE_BUILD_TYPE=%configuration%" ..
+  - cmake -G "%generator%" "-DCMAKE_BUILD_TYPE=%configuration%" -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON ..
   - cmake --build . --config %configuration%
 
 test_script:

cmake/HandleGTest.cmake

@@ -0,0 +1,77 @@
+
+macro(split_list listname)
+  string(REPLACE ";" " " ${listname} "${${listname}}")
+endmacro()
+
+macro(build_external_gtest)
+  include(ExternalProject)
+  set(GTEST_FLAGS "")
+  if (BENCHMARK_USE_LIBCXX)
+    if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+      list(APPEND GTEST_FLAGS -stdlib=libc++)
+    else()
+      message(WARNING "Unsupported compiler (${CMAKE_CXX_COMPILER}) when using libc++")
+    endif()
+  endif()
+  if (BENCHMARK_BUILD_32_BITS)
+    list(APPEND GTEST_FLAGS -m32)
+  endif()
+  if (NOT "${CMAKE_CXX_FLAGS}" STREQUAL "")
+    list(APPEND GTEST_FLAGS ${CMAKE_CXX_FLAGS})
+  endif()
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" GTEST_BUILD_TYPE)
+  if ("${GTEST_BUILD_TYPE}" STREQUAL "COVERAGE")
+    set(GTEST_BUILD_TYPE "DEBUG")
+  endif()
+  split_list(GTEST_FLAGS)
+  ExternalProject_Add(googletest
+      EXCLUDE_FROM_ALL ON
+      GIT_REPOSITORY https://github.com/google/googletest.git
+      GIT_TAG master
+      PREFIX "${CMAKE_BINARY_DIR}/googletest"
+      INSTALL_DIR "${CMAKE_BINARY_DIR}/googletest"
+      CMAKE_CACHE_ARGS
+        -DCMAKE_BUILD_TYPE:STRING=${GTEST_BUILD_TYPE}
+        -DCMAKE_C_COMPILER:STRING=${CMAKE_C_COMPILER}
+        -DCMAKE_CXX_COMPILER:STRING=${CMAKE_CXX_COMPILER}
+        -DCMAKE_INSTALL_PREFIX:PATH=<INSTALL_DIR>
+        -DCMAKE_CXX_FLAGS:STRING=${GTEST_FLAGS}
+        -Dgtest_force_shared_crt:BOOL=ON
+      )
+
+  ExternalProject_Get_Property(googletest install_dir)
+
+  add_library(gtest UNKNOWN IMPORTED)
+  add_library(gtest_main UNKNOWN IMPORTED)
+
+  set(LIB_SUFFIX "${CMAKE_STATIC_LIBRARY_SUFFIX}")
+  set(LIB_PREFIX "${CMAKE_STATIC_LIBRARY_PREFIX}")
+
+  if("${GTEST_BUILD_TYPE}" STREQUAL "DEBUG")
+    set(LIB_SUFFIX "d${CMAKE_STATIC_LIBRARY_SUFFIX}")
+  endif()
+  file(MAKE_DIRECTORY ${install_dir}/include)
+  set_target_properties(gtest PROPERTIES
+    IMPORTED_LOCATION ${install_dir}/lib/${LIB_PREFIX}gtest${LIB_SUFFIX}
+    INTERFACE_INCLUDE_DIRECTORIES ${install_dir}/include
+  )
+  set_target_properties(gtest_main PROPERTIES
+    IMPORTED_LOCATION ${install_dir}/lib/${LIB_PREFIX}gtest_main${LIB_SUFFIX}
+    INTERFACE_INCLUDE_DIRECTORIES ${install_dir}/include
+  )
+  add_dependencies(gtest googletest)
+  add_dependencies(gtest_main googletest)
+  set(GTEST_BOTH_LIBRARIES gtest gtest_main)
+  #set(GTEST_INCLUDE_DIRS ${install_dir}/include)
+endmacro(build_external_gtest)
+
+if (BENCHMARK_ENABLE_GTEST_TESTS)
+  if (IS_DIRECTORY ${CMAKE_SOURCE_DIR}/googletest)
+    add_subdirectory(${CMAKE_SOURCE_DIR}/googletest)
+    set(GTEST_BOTH_LIBRARIES gtest gtest_main)
+  elseif(BENCHMARK_DOWNLOAD_DEPENDENCIES)
+    build_external_gtest()
+  else()
+    find_package(GTest REQUIRED)
+  endif()
+endif()

test/CMakeLists.txt

@@ -42,7 +42,6 @@ macro(compile_output_test name)
           ${BENCHMARK_CXX_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
 endmacro(compile_output_test)
 
-
 # Demonstration executable
 compile_benchmark_test(benchmark_test)
 add_test(benchmark benchmark_test --benchmark_min_time=0.01)
@@ -135,6 +134,29 @@ endif()
 compile_output_test(complexity_test)
 add_test(complexity_benchmark complexity_test --benchmark_min_time=${COMPLEXITY_MIN_TIME})
 
+###############################################################################
+# GoogleTest Unit Tests
+###############################################################################
+
+if (BENCHMARK_ENABLE_GTEST_TESTS)
+  macro(compile_gtest name)
+    add_executable(${name} "${name}.cc")
+    if (TARGET googletest)
+      add_dependencies(${name} googletest)
+    endif()
+    target_link_libraries(${name} benchmark
+        "${GTEST_BOTH_LIBRARIES}" ${CMAKE_THREAD_LIBS_INIT})
+  endmacro(compile_gtest)
+
+  macro(add_gtest name)
+    compile_gtest(${name})
+    add_test(${name} ${name})
+  endmacro()
+
+  add_gtest(statistics_test)
+endif(BENCHMARK_ENABLE_GTEST_TESTS)
+
+
 # Add the coverage command(s)
 if(CMAKE_BUILD_TYPE)
   string(TOLOWER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE_LOWER)

test/statistics_test.cc

@@ -0,0 +1,61 @@
+//===---------------------------------------------------------------------===//
+// statistics_test - Unit tests for src/statistics.cc
+//===---------------------------------------------------------------------===//
+
+#include "../src/statistics.h"
+#include "gtest/gtest.h"
+
+namespace {
+TEST(StatisticsTest, Mean) {
+  std::vector<double> Inputs;
+  {
+    Inputs = {42, 42, 42, 42};
+    double Res = benchmark::StatisticsMean(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 42.0);
+  }
+  {
+    Inputs = {1, 2, 3, 4};
+    double Res = benchmark::StatisticsMean(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 2.5);
+  }
+  {
+    Inputs = {1, 2, 5, 10, 10, 14};
+    double Res = benchmark::StatisticsMean(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 7.0);
+  }
+}
+
+TEST(StatisticsTest, Median) {
+  std::vector<double> Inputs;
+  {
+    Inputs = {42, 42, 42, 42};
+    double Res = benchmark::StatisticsMedian(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 42.0);
+  }
+  {
+    Inputs = {1, 2, 3, 4};
+    double Res = benchmark::StatisticsMedian(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 2.5);
+  }
+  {
+    Inputs = {1, 2, 5, 10, 10};
+    double Res = benchmark::StatisticsMedian(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 5.0);
+  }
+}
+
+TEST(StatisticsTest, StdDev) {
+  std::vector<double> Inputs;
+  {
+    Inputs = {101, 101, 101, 101};
+    double Res = benchmark::StatisticsStdDev(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 0.0);
+  }
+  {
+    Inputs = {1, 2, 3};
+    double Res = benchmark::StatisticsStdDev(Inputs);
+    EXPECT_DOUBLE_EQ(Res, 1.0);
+  }
+}
+
+}  // end namespace