From f62ca21dd11fcf7a6f4658a4859838f76730547e Mon Sep 17 00:00:00 2001
From: Paul Dreik <github@pauldreik.se>
Date: Tue, 10 Nov 2020 19:55:04 +0100
Subject: [PATCH] enable boost json (#1292)

* bump boost.json and see if it works in simdjson CI

* enable boost json

* clean up

* add boost json to deps

* use boost if std::string_view is available

* add build with c++20

* use docker image which has the proper libc++ installed
---
 .drone.yml                       | 21 +++++++++++++++++++++
 benchmark/parsingcompetition.cpp | 10 ++--------
 dependencies/CMakeLists.txt      | 21 ++++++++++++---------
 3 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/.drone.yml b/.drone.yml
index 738de635..e55b44f2 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -183,6 +183,27 @@ steps:
     - ASAN_OPTIONS="detect_leaks=0" ctest $CTEST_FLAGS -LE "acceptance|per_implementation" # Everything we haven't run yet, run now.
 ---
 kind: pipeline
+name: cpp20-clang11-libcpp
+platform: { os: linux, arch: amd64 }
+steps:
+- name: Build and Test
+  image: pauldreik/llvm-11
+  user: root
+  environment:
+    CC: clang-11
+    CXX: clang++-11
+    CMAKE_FLAGS: -GNinja
+    BUILD_FLAGS:
+    CTEST_FLAGS: -j4 --output-on-failure -E checkperf
+    CXXFLAGS: -std=c++20 -stdlib=libc++
+  commands:
+    - mkdir build
+    - cd build
+    - cmake $CMAKE_FLAGS ..
+    - cmake --build . $BUILD_FLAGS
+    - ctest $CTEST_FLAGS
+---
+kind: pipeline
 name: arm64-gcc8
 platform: { os: linux, arch: arm64 }
 steps:
diff --git a/benchmark/parsingcompetition.cpp b/benchmark/parsingcompetition.cpp
index 25c3d331..4a2f2192 100644
--- a/benchmark/parsingcompetition.cpp
+++ b/benchmark/parsingcompetition.cpp
@@ -27,13 +27,7 @@ SIMDJSON_PUSH_DISABLE_ALL_WARNINGS
 #include <nlohmann/json.hpp>
 using json = nlohmann::json;
 
-#if defined(__clang__)
-// Under some clang/libc++ configurations, boost json fails
-// to build.
-#define DISABLE_BOOST_JSON
-#endif
-
-#ifndef DISABLE_BOOST_JSON
+#ifdef HAS_BOOST_JSON
 #include <boost/json/parser.hpp>
 #include <boost/json/monotonic_resource.hpp>
 #endif
@@ -185,7 +179,7 @@ bool bench(const char *filename, bool verbose, bool just_data,
             std::memcpy(buffer, p.data(), p.size()) &&
                 (buffer[p.size()] = '\0'),
             repeat, volume, !just_data);
-#ifndef DISABLE_BOOST_JSON
+#ifdef HAS_BOOST_JSON
   {
     const boost::json::string_view sv(p.data(), p.size());
     boost::json::parser p;
diff --git a/dependencies/CMakeLists.txt b/dependencies/CMakeLists.txt
index 8ec83bcb..51ab3a31 100644
--- a/dependencies/CMakeLists.txt
+++ b/dependencies/CMakeLists.txt
@@ -14,13 +14,15 @@ endif()
 # This prevents variables declared with set() from unnecessarily escaping and
 # should not be called more than once
 function(competition_scope_)
-  # Boost JSON is not compatible with some clang/libc++ configurations.
-  if(NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    import_dependency(boostjson CPPAlliance/json a0983f7)
-    add_library(boostjson STATIC "${boostjson_SOURCE_DIR}/src/src.cpp")
-    target_compile_definitions(boostjson PUBLIC BOOST_JSON_STANDALONE)
-    target_include_directories(boostjson SYSTEM PUBLIC
-            "${boostjson_SOURCE_DIR}/include")
+  # boost json in standalone mode requires C++17 string_view
+  include(CheckCXXSourceCompiles)
+  check_cxx_source_compiles("#include <string_view>\n#if __cpp_lib_string_view < 201606\n#error no string view support\n#endif\nint main(){}" USE_BOOST_JSON)
+  if(USE_BOOST_JSON)
+  import_dependency(boostjson boostorg/json ee8d72d8502b409b5561200299cad30ccdb91415)
+  add_library(boostjson STATIC "${boostjson_SOURCE_DIR}/src/src.cpp")
+  target_compile_definitions(boostjson PUBLIC BOOST_JSON_STANDALONE)
+  target_include_directories(boostjson SYSTEM PUBLIC
+          "${boostjson_SOURCE_DIR}/include")
   endif()
 
   import_dependency(cjson DaveGamble/cJSON c69134d)
@@ -87,8 +89,9 @@ function(competition_scope_)
 
   add_library(competition-core INTERFACE)
   target_link_libraries(competition-core INTERFACE nlohmann_json rapidjson sajson cjson jsmn yyjson)
-  if(NOT CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    target_link_libraries(competition-core INTERFACE boostjson)
+  if(USE_BOOST_JSON)
+     target_compile_definitions(boostjson INTERFACE HAS_BOOST_JSON)
+     target_link_libraries(competition-core INTERFACE boostjson)
   endif()
 
   add_library(competition-all INTERFACE)