From 7ebe5c4bcf57de3407aa5ed19971f08a1e50b35a Mon Sep 17 00:00:00 2001
From: Daniel Lemire <lemire@gmail.com>
Date: Sun, 21 Jun 2020 14:20:58 -0400
Subject: [PATCH] This might enable folks to just build the library.

---
 .circleci/config.yml | 12 ++++++++----
 CMakeLists.txt       | 34 ++++++++++++++++++++++------------
 simdjson-flags.cmake |  2 +-
 3 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index b44c2364..ed5df345 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -83,14 +83,13 @@ commands:
       - run: |
           cd build &&
           cmake $CMAKE_FLAGS -DCMAKE_INSTALL_PREFIX:PATH=destination .. &&
-          make $BUILD_FLAGS all &&
-          tools/json2json -h # Print out the implementation we're using on this hardware
+          make $BUILD_FLAGS all
 
   cmake_test:
     steps:
       - cmake_build
       - run: |
-          cd build &&
+          cd build && tools/json2json -h &&
           ctest $CTEST_FLAGS -L acceptance &&
           ctest $CTEST_FLAGS -LE acceptance -E checkperf
 
@@ -98,7 +97,7 @@ commands:
     steps:
       - cmake_build
       - run: |
-          cd build &&
+          cd build &&  tools/json2json -h &&
           ctest $CTEST_FLAGS -L acceptance -LE per_implementation &&
           SIMDJSON_FORCE_IMPLEMENTATION=haswell ctest $CTEST_FLAGS -L per_implementation &&
           SIMDJSON_FORCE_IMPLEMENTATION=westmere ctest $CTEST_FLAGS -L per_implementation &&SIMDJSON_FORCE_IMPLEMENTATION=fallback ctest $CTEST_FLAGS -L per_implementation &&
@@ -119,6 +118,11 @@ jobs:
     executor: gcc7
     environment: { CMAKE_FLAGS: -DSIMDJSON_GOOGLE_BENCHMARKS=ON }
     steps: [ install_cmake, cmake_test, cmake_install_test ]
+  gcc10justlib:
+    description: Build just the library, install it and do a basic test
+    executor: gcc10
+    environment: { CMAKE_FLAGS: -SIMDJSON_JUST_LIBRARY=ON }
+    steps: [ cmake_build, cmake_install_test ]
   gcc10:
     description: Build and run tests on GCC 10 and AVX 2 with a cmake static build
     executor: gcc10
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 755f74c3..0de496a7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,14 +16,20 @@ include(GNUInstallDirs)
 include(simdjson-flags.cmake)
 include(simdjson-user-cmakecache.cmake)
 
+if(SIMDJSON_JUST_LIBRARY)
+  MESSAGE( STATUS "Building just the library, omitting all tests, tools and benchmarks." )
+endif()
+
 #
 # Set up test data
 #
-enable_testing()
-add_subdirectory(jsonchecker)
-add_subdirectory(jsonexamples)
-add_library(test-data INTERFACE)
-target_link_libraries(test-data INTERFACE jsonchecker-data jsonexamples-data)
+if(NOT(SIMDJSON_JUST_LIBRARY))
+  enable_testing()
+  add_subdirectory(jsonchecker)
+  add_subdirectory(jsonexamples)
+  add_library(test-data INTERFACE)
+  target_link_libraries(test-data INTERFACE jsonchecker-data jsonexamples-data)
+endif()
 
 #
 # Create the top level simdjson library (must be done at this level to use both src/ and include/
@@ -32,17 +38,21 @@ target_link_libraries(test-data INTERFACE jsonchecker-data jsonexamples-data)
 add_subdirectory(include)
 add_subdirectory(src)
 add_subdirectory(windows)
-add_subdirectory(tools)
-add_subdirectory(singleheader)
+if(NOT(SIMDJSON_JUST_LIBRARY))
+  add_subdirectory(tools)
+  add_subdirectory(singleheader)
+endif()
 
 #
 # Compile tools / tests / benchmarks
 #
-add_subdirectory(dependencies)
-add_subdirectory(tests)
-add_subdirectory(examples)
-add_subdirectory(benchmark)
-add_subdirectory(fuzz)
+if(NOT(SIMDJSON_JUST_LIBRARY))
+  add_subdirectory(dependencies)
+  add_subdirectory(tests)
+  add_subdirectory(examples)
+  add_subdirectory(benchmark)
+  add_subdirectory(fuzz)
+endif()
 
 #
 # Source files should be just ASCII
diff --git a/simdjson-flags.cmake b/simdjson-flags.cmake
index c64ebe6b..ba51b988 100644
--- a/simdjson-flags.cmake
+++ b/simdjson-flags.cmake
@@ -1,4 +1,4 @@
-
+option(SIMDJSON_JUST_LIBRARY "Buld just the library, omit tests, tools and benchmarks" OFF)
 #
 # Flags used by exes and by the simdjson library (project-wide flags)
 #