initial commit with the build on windows

.gitmodules

@@ -1,3 +1,9 @@
 [submodule "third_party/prometheus-cpp"]
 	path = third_party/prometheus-cpp
 	url = https://github.com/jupp0r/prometheus-cpp.git
+[submodule "tools/vcpkg"]
+	path = tools/vcpkg
+	url = https://github.com/Microsoft/vcpkg
+[submodule "third_party/benchmark"]
+	path = third_party/benchmark
+	url = https://github.com/google/benchmark

tools/build-benchmarks.cmd

@@ -0,0 +1,35 @@
+@echo off
+set VS_TOOLS_VERSION=vs2019
+set CMAKE_GEN="Visual Studio 16 2019"
+echo Building Google Benchmark (test only dependency)...
+@setlocal ENABLEEXTENSIONS
+
+echo Auto-detecting Visual Studio version...
+call "%~dp0\vcvars.cmd"
+
+pushd "%~dp0\.."
+set "ROOT=%CD%"
+
+set MAXCPUCOUNT=%NUMBER_OF_PROCESSORS%
+set platform=
+
+if not exist "%ROOT%\third_party\benchmark\" (
+  echo "Google Benchmark library is not available, skipping benchmark build."
+  call skip_the_build
+)
+
+cd "%ROOT%\third_party\benchmark\"
+set "GOOGLETEST_PATH=%ROOT%\third_party\googletest"
+if not exist "build" (
+  mkdir build
+)
+cd build
+
+REM By default we generate the project for the older Visual Studio 2017 even if we have newer version installed
+cmake ../ -G %CMAKE_GEN% -Ax64 -DBENCHMARK_ENABLE_TESTING=OFF
+set SOLUTION=%ROOT%\third_party\benchmark\build\benchmark.sln
+msbuild %SOLUTION% /maxcpucount:%MAXCPUCOUNT% /p:Configuration=Debug /p:Platform=x64
+msbuild %SOLUTION% /maxcpucount:%MAXCPUCOUNT% /p:Configuration=Release /p:Platform=x64
+popd
+
+:skip_the_build

tools/build-vs2019-x64.cmd

@@ -0,0 +1,5 @@
+set "VS_TOOLS_VERSION=vs2019"
+set "CMAKE_GEN=Visual Studio 16 2019"
+cd %~dp0
+call setup-buildtools.cmd
+call build.cmd

tools/build.cmd

@@ -0,0 +1,74 @@
+@echo off
+REM Currently we require Visual Studio 2019 for C++20 build targeting Release/x64.
+REM
+REM TODO: allow specifying compiler version as argument.
+REM
+REM Supported versions for nostd build:
+REM - vs2015 (C++11)
+REM - vs2017 (C++14)
+REM - vs2019 (C++20)
+REM
+REM Supported versions for STL build:
+REM - vs2017 (C++14)
+REM - vs2019 (C++20)
+REM
+
+if "%VS_TOOLS_VERSION%" == "" set "VS_TOOLS_VERSION=vs2019"
+if "%CMAKE_GEN%"        == "" set "CMAKE_GEN=Visual Studio 16 2019"
+
+pushd %~dp0
+setlocal enableextensions
+setlocal enabledelayedexpansion
+set "ROOT=%~dp0\.."
+
+REM Use preinstalled vcpkg if installed or use our local
+if "%VCPKG_INSTALLATION_ROOT%" neq "" (
+  set "VCPKG_CMAKE=%VCPKG_INSTALLATION_ROOT%\scripts\buildsystems\vcpkg.cmake"
+) else (
+  set "VCPKG_CMAKE=%CD%\vcpkg\scripts\buildsystems\vcpkg.cmake"
+)
+
+REM ********************************************************************
+REM Setup compiler environment
+REM ********************************************************************
+call "%~dp0\vcvars.cmd"
+
+
+REM ********************************************************************
+REM Use cmake
+REM ********************************************************************
+set "PATH=%PATH%;C:\Program Files\CMake\bin\"
+
+REM ********************************************************************
+REM Build with nostd implementation
+REM ********************************************************************
+set CONFIG=-DWITH_STL:BOOL=OFF %*
+set "OUTDIR=%ROOT%\out\%VS_TOOLS_VERSION%\nostd"
+call :build_config
+
+REM ********************************************************************
+REM Build with STL implementation - only for vs2017+
+REM ********************************************************************
+if "%VS_TOOLS_VERSION%" neq "vs2015" (
+  set CONFIG=-DWITH_STL:BOOL=ON
+  set "OUTDIR=%ROOT%\out\%VS_TOOLS_VERSION%\stl"
+  call :build_config
+)
+
+popd
+REM ********************************************************************
+
+
+REM ********************************************************************
+REM Function that allows to build given build configuration
+REM ********************************************************************
+:build_config
+REM TODO: consider rmdir for clean builds
+if not exist "%OUTDIR%" mkdir "%OUTDIR%"
+cd "%OUTDIR%"
+REM Optional platform specification parameter below: -Ax64
+cmake %ROOT% -G "%CMAKE_GEN%" -DCMAKE_TOOLCHAIN_FILE="%VCPKG_CMAKE%" %CONFIG%
+set "SOLUTION=%OUTDIR%\opentelemetry-cpp.sln"
+REM TODO: allow building [Release|Debug]x[Win32|x64|ARM|ARM64]
+msbuild "%SOLUTION%" /p:Configuration=Release /p:Platform=x64 /p:VcpkgEnabled=true
+exit /b 0

tools/ports/benchmark/CONTROL

@@ -0,0 +1,5 @@
+Source: benchmark
+Version: 1.5.1
+Homepage: https://github.com/google/benchmark
+Description: A library to support the benchmarking of functions, similar to unit-tests.
+Supports: !uwp

tools/ports/benchmark/portfile.cmake

@@ -0,0 +1,49 @@
+if(VCPKG_CMAKE_SYSTEM_NAME STREQUAL "WindowsStore")
+  message(FATAL_ERROR "${PORT} does not currently support UWP")
+endif()
+
+if (VCPKG_PLATFORM_TOOLSET STREQUAL "v140")
+  # set(CMAKE_C_COMPILER_WORKS 1)
+  # set(CMAKE_CXX_COMPILER_WORKS 1)
+  set(CMAKE_C_COMPILER cl.exe)
+  set(CMAKE_CXX_COMPILER cl.exe)
+  set(MSVC_TOOLSET_VERSION 140)
+  # set(VCPKG_VISUAL_STUDIO_PATH "C:\\Program Files (x86)\\Microsoft Visual Studio 14.0")
+  # set(VCPKG_PLATFORM_TOOLSET v140)
+else()
+  # Make sure vs2019 compiled binaries are compat with vs2017
+  set(VCPKG_CXX_FLAGS "/Zc:__cplusplus /d2FH4-")
+  set(VCPKG_C_FLAGS "/Zc:__cplusplus /d2FH4-")
+  set(PREFER PREFER_NINJA)
+endif()
+
+include(vcpkg_common_functions)
+
+vcpkg_check_linkage(ONLY_STATIC_LIBRARY)
+
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO google/benchmark
+    HEAD_REF master
+)
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    ${PREFER}
+    OPTIONS
+        -DBENCHMARK_ENABLE_TESTING=OFF
+        -DCMAKE_DEBUG_POSTFIX=d
+)
+
+vcpkg_install_cmake()
+
+vcpkg_copy_pdbs()
+
+vcpkg_fixup_cmake_targets(CONFIG_PATH lib/cmake/benchmark)
+
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)
+file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/share)
+
+# Handle copyright
+file(COPY ${SOURCE_PATH}/LICENSE DESTINATION ${CURRENT_PACKAGES_DIR}/share/benchmark)
+file(RENAME ${CURRENT_PACKAGES_DIR}/share/benchmark/LICENSE ${CURRENT_PACKAGES_DIR}/share/benchmark/copyright)

tools/setup-buildtools.cmd

@@ -0,0 +1,50 @@
+@echo off
+set "PATH=%PATH%;%~dp0;%~dp0\vcpkg"
+pushd %~dp0
+
+REM Fail if chocolatey is not installed
+where /Q choco
+if ERRORLEVEL 1 (
+  echo This script requires chocolatey. Installation instructions: https://chocolatey.org/docs/installation
+  exit -1
+)
+
+REM Print current Visual Studio installations detected
+where /Q vswhere
+if ERRORLEVEL 0 (
+  echo Visual Studio installations detected:
+  vswhere -property installationPath
+)
+
+REM Install tools needed for building stuff
+choco install -y cmake
+choco install -y svn
+choco install -y git
+choco install -y llvm
+choco install -y zip
+
+REM Try to autodetect Visual Studio
+call "%~dp0\vcvars.cmd"
+if "%TOOLS_VS_NOTFOUND%" == "1" (
+  REM Cannot detect MSBuild path
+  REM TODO: no command line tools..
+  REM TODO: use MSBuild from vswhere?
+)
+
+where /Q vcpkg.exe
+if ERRORLEVEL 1 (
+  REM Build our own vcpkg from source
+  pushd .\vcpkg
+  call bootstrap-vcpkg.bat
+  popd
+)
+
+REM Install it
+vcpkg install gtest:x64-windows
+vcpkg install --head --overlay-ports=%~dp0\ports benchmark:x64-windows
+vcpkg install ms-gsl:x64-windows
+vcpkg install nlohmann-json:x64-windows
+vcpkg install abseil:x64-windows
+vcpkg integrate install
+popd
+exit /b 0

tools/vcvars.cmd

@@ -0,0 +1,86 @@
+@echo off
+REM
+REM Make sure to enable the 'Visual C++ ATL' components for all platforms during the setup.
+REM
+REM This build script auto-detects and configures Visual Studio in the following order:
+REM 1. Visual Studio 2017 Enterprise
+REM 2. Visual Studio 2017 BuildTools
+REM 3. Visual Studio 2019 Enterprise
+REM 4. Visual Studio 2019 Community
+REM 5. Visual Studio 2019 BuildTools
+REM
+
+REM 1st parameter - Visual Studio version
+if "%1" neq "" (
+  goto %1
+)
+
+if "%VS_TOOLS_VERSION%" neq "" (
+  goto %VS_TOOLS_VERSION%
+)
+
+REM vs2017 Enterprise
+:vs2017
+:vs2017_enterprise
+set TOOLS_VS2017_ENTERPRISE="%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Enterprise\Common7\Tools\VsDevCmd.bat"
+if exist %TOOLS_VS2017_ENTERPRISE% (
+  echo Building with vs2017 Enterprise...
+  call %TOOLS_VS2017_ENTERPRISE%
+  goto tools_configured
+)
+
+REM vs2017 BuildTools
+:vs2017_buildtools
+set TOOLS_VS2017="%ProgramFiles(x86)%\Microsoft Visual Studio\2017\BuildTools\Common7\Tools\VsDevCmd.bat"
+if exist %TOOLS_VS2017% (
+  echo Building with vs2017 BuildTools...
+  call %TOOLS_VS2017%
+  goto tools_configured
+)
+
+REM vs2019 Enterprise
+:vs2019
+:vs2019_enterprise
+set TOOLS_VS2019_ENTERPRISE="%ProgramFiles(x86)%\Microsoft Visual Studio\2019\Enterprise\Common7\Tools\VsDevCmd.bat"
+if exist %TOOLS_VS2019_ENTERPRISE% (
+  echo Building with vs2019 Enterprise...
+  call %TOOLS_VS2019_ENTERPRISE%
+  goto tools_configured
+)
+
+REM vs2019 Community
+:vs2019_community
+set TOOLS_VS2019_COMMUNITY="%ProgramFiles(x86)%\Microsoft Visual Studio\2019\Community\Common7\Tools\VsDevCmd.bat"
+if exist %TOOLS_VS2019_COMMUNITY% (
+  echo Building with vs2019 Community...
+  call %TOOLS_VS2019_COMMUNITY%
+  goto tools_configured
+)
+
+REM vs2019 BuildTools
+:vs2019_buildtools
+set TOOLS_VS2019="%ProgramFiles(x86)%\Microsoft Visual Studio\2019\BuildTools\Common7\Tools\VsDevCmd.bat"
+if exist %TOOLS_VS2019% (
+  echo Building with vs2019 BuildTools...
+  call %TOOLS_VS2019%
+  goto tools_configured
+)
+
+REM vs2015
+:vs2015
+set TOOLS_VS2015="%ProgramFiles(x86)%\Microsoft Visual Studio 14.0\VC\bin\vcvars32.bat"
+if exist %TOOLS_VS2015% (
+  echo Building with vs2015 BuildTools...
+  call %TOOLS_VS2015%
+  set "VCPKG_VISUAL_STUDIO_PATH=C:\Program Files (x86)\Microsoft Visual Studio 14.0"
+  set VCPKG_PLATFORM_TOOLSET=v140
+  goto tools_configured
+)
+
+echo WARNING:*********************************************
+echo WARNING: cannot auto-detect Visual Studio version !!!
+echo WARNING:*********************************************
+set TOOLS_VS_NOTFOUND=1
+exit /b 0
+
+:tools_configured