CMakeLists.txt: export target gemmi_headers

instead of setting CMAKE_CXX_STANDARD set compile features to cxx_std_11

.appveyor.yml

@@ -12,16 +12,16 @@
       - arch: x64
         CMAKE_GENERATOR: Visual Studio 16 2019
         CMAKE_CONFIG: RelWithDebInfo
-        CMAKE_ARGS: -DCMAKE_CXX_STANDARD=11 -DUSE_PYTHON=1 -DPython_EXECUTABLE="C:\\Python38-x64\\python.exe"
+        CMAKE_ARGS: -DCMAKE_CXX_STANDARD=11 -DUSE_PYTHON=1 -DPython_EXECUTABLE="C:\\Python310-x64\\python.exe"
         APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
-        PY_PYTHON: 3.8
+        PY_PYTHON: 3.10
         USE_PIP: 1
       - arch: x86
         CMAKE_GENERATOR: Visual Studio 15 2017
         CMAKE_CONFIG: MinSizeRel
-        CMAKE_ARGS: -DUSE_PYTHON=1 -DPython_EXECUTABLE="C:\\Python310\\python.exe"
+        CMAKE_ARGS: -DUSE_PYTHON=1 -DPython_EXECUTABLE="C:\\Python38\\python.exe"
         APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-        PY_PYTHON: 3.10-32
+        PY_PYTHON: 3.8-32
       - arch: x64
         CMAKE_GENERATOR: MSYS Makefiles
         CMAKE_ARGS: -DCMAKE_CXX_STANDARD=14
@@ -30,7 +30,7 @@
         CMAKE_CONFIG: Release
         APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
         PY_PYTHON: 3.9-32
-        USE_SETUP_PY: 1
+        USE_PIP_INSTALL: 1
 
   build_script:
   - if defined BINDIR (set "PATH=%BINDIR%;%PATH%")
@@ -47,7 +47,7 @@
   - if exist "%CMAKE_CONFIG%\gemmi*.pyd" (copy "%CMAKE_CONFIG%\gemmi*.pyd" . /y)
   - dir C:\mingw-w64\
   - py -c "import sys; print(sys.version+'\n'+sys.executable)"
-  - if defined USE_SETUP_PY (py setup.py install)
+  - if defined USE_PIP_INSTALL (py -m pip install .)
   - cmd: '"%VS140COMNTOOLS%\..\..\VC\vcvarsall.bat" %ARCH%'
 
   test_script:

CMakeLists.txt

@@ -73,24 +73,7 @@ if (DEFINED ENV{EXTRA_WFLAGS})
   set(EXTRA_WARNINGS ON CACHE BOOL "Set extra warning flags" FORCE)
 endif()
 
-if (NOT CMAKE_CXX_STANDARD)
-  if (CMAKE_CXX20_STANDARD_COMPILE_OPTION)
-    set(CMAKE_CXX_STANDARD 20)
-  elseif (CMAKE_CXX17_STANDARD_COMPILE_OPTION)
-    # Python bindings don't compile as C++17 in VS 2017
-    if (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
-      set(CMAKE_CXX_STANDARD 14)
-    else()
-      set(CMAKE_CXX_STANDARD 17)
-    endif()
-  elseif (CMAKE_CXX11_STANDARD_COMPILE_OPTION)
-    set(CMAKE_CXX_STANDARD 11)
-  endif()
-endif()
-message(STATUS "Compiling with C++ standard: ${CMAKE_CXX_STANDARD}")
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
-
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 include(CheckIncludeFile)  # for check_include_file
@@ -123,9 +106,6 @@ else (NOT benchmark_FOUND)
   message(STATUS "Benchmarks not configured.")
 endif()
 
-include_directories("${CMAKE_CURRENT_SOURCE_DIR}/include"
-                    "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
-
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang|GNU" AND EXTRA_WARNINGS)
   set(CMAKE_CXX_FLAGS
       "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic -Wformat=2 -Wredundant-decls -Wfloat-conversion -Wdisabled-optimization -Wshadow $ENV{EXTRA_WFLAGS}")
@@ -189,13 +169,13 @@ endif()
 #  target_link_libraries(fgemmi PRIVATE cgemmi)
 #endif()
 
-
-### programs from prog/ ###
-
-add_library(options OBJECT prog/options.cpp)
-if (GEMMI_VERSION_INFO)
-  target_compile_definitions(options PRIVATE GEMMI_VERSION_INFO=${GEMMI_VERSION_INFO})
-endif()
+add_library(gemmi_headers INTERFACE)
+add_library(gemmi::gemmi_headers ALIAS gemmi_headers)
+add_library(gemmi::headers ALIAS gemmi_headers)
+target_include_directories(gemmi_headers INTERFACE
+    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
+    "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+target_compile_features(gemmi_headers INTERFACE cxx_std_11)
 
 add_library(gemmi_cpp
             src/assembly.cpp src/calculate.cpp src/crd.cpp
@@ -207,26 +187,36 @@ add_library(gemmi_cpp
 set_property(TARGET gemmi_cpp PROPERTY POSITION_INDEPENDENT_CODE ON)
 #set_property(TARGET gemmi_cpp PROPERTY CXX_VISIBILITY_PRESET hidden)
 target_compile_definitions(gemmi_cpp PRIVATE GEMMI_BUILD)
+target_include_directories(gemmi_cpp PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
+
 if (BUILD_SHARED_LIBS)
   target_compile_definitions(gemmi_cpp PUBLIC GEMMI_SHARED)
 endif()
-if (DEFINED CMAKE_CXX_STANDARD)
-  target_compile_features(gemmi_cpp PUBLIC "cxx_std_${CMAKE_CXX_STANDARD}")
-endif()
+target_link_libraries(gemmi_cpp PUBLIC gemmi_headers)
 support_gz(gemmi_cpp)
-target_include_directories(gemmi_cpp PUBLIC
-    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>"
-    "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+
+### programs from prog/ ###
+
+add_library(options OBJECT prog/options.cpp)
+target_link_libraries(options PUBLIC gemmi_headers)
+target_include_directories(options PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
+if (GEMMI_VERSION_INFO)
+  target_compile_definitions(options PRIVATE GEMMI_VERSION_INFO=${GEMMI_VERSION_INFO})
+endif()
 
 # Gemmi subcommands compiled as individual binaries.
 # Not built by default and used mostly for testing.
 function(add_single_prog target)
   cmake_parse_arguments(arg "NOLIB;GZ" "ADD_SRC" "" ${ARGN})
   add_executable(gemmi-${target} EXCLUDE_FROM_ALL prog/${target}.cpp ${arg_ADD_SRC}
                  $<TARGET_OBJECTS:options>)
-  if (NOT arg_NOLIB)
+  if (arg_NOLIB)
+    target_link_libraries(gemmi-${target} PRIVATE gemmi_headers)
+  else()
     target_link_libraries(gemmi-${target} PRIVATE gemmi_cpp)
   endif()
+  target_include_directories(gemmi-${target} PRIVATE
+                             "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
   if (arg_GZ)
     support_gz(gemmi-${target})
   endif()
@@ -281,6 +271,7 @@ add_executable(gemmi_prog
                $<TARGET_OBJECTS:options>)
 target_link_libraries(gemmi_prog PRIVATE gemmi_cpp)
 support_gz(gemmi_prog)
+target_include_directories(gemmi_prog PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
 target_compile_definitions(gemmi_prog PRIVATE GEMMI_ALL_IN_ONE=1)
 set_property(TARGET gemmi_prog PROPERTY OUTPUT_NAME gemmi)
 if (WIN32 AND USE_WMAIN)
@@ -312,12 +303,17 @@ endif()
 add_executable(cpptest EXCLUDE_FROM_ALL tests/main.cpp tests/cif.cpp
                                         src/mtz2cif.cpp src/eig3.cpp src/sprintf.cpp)
 target_compile_definitions(cpptest PRIVATE USE_STD_SNPRINTF=1)
+target_link_libraries(cpptest PRIVATE gemmi_headers)
+target_include_directories(cpptest PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/third_party")
 
 add_executable(hello EXCLUDE_FROM_ALL examples/hello.cpp)
+target_link_libraries(hello PRIVATE gemmi_headers)
 add_executable(doc_example EXCLUDE_FROM_ALL
                docs/code/sym.cpp docs/code/elem.cpp docs/code/resinfo.cpp
                docs/code/cell.cpp src/resinfo.cpp)
+target_link_libraries(doc_example PRIVATE gemmi_headers)
 add_executable(doc_example2 EXCLUDE_FROM_ALL docs/code/cif_cc.cpp)
+target_link_libraries(doc_example2 PRIVATE gemmi_headers)
 add_executable(doc_maybegz EXCLUDE_FROM_ALL docs/code/maybegz.cpp docs/code/mutate.cpp)
 target_link_libraries(doc_maybegz PRIVATE gemmi_cpp)
 support_gz(doc_maybegz)
@@ -336,6 +332,7 @@ support_gz(test_disulf)
 
 # auth_label requires <experimental/filesystem> and -lstdc++fs
 add_executable(auth_label EXCLUDE_FROM_ALL examples/auth_label.cpp)
+target_link_libraries(auth_label PRIVATE gemmi_headers)
 if (NOT MSVC)
   target_link_libraries(auth_label PRIVATE stdc++fs)
 endif()
@@ -381,7 +378,7 @@ if (benchmark_FOUND)
     if (b MATCHES "resinfo|pdb|writecif")
       target_link_libraries(${b}-bm PRIVATE gemmi_cpp)
     endif()
-    target_link_libraries(${b}-bm PRIVATE benchmark::benchmark)
+    target_link_libraries(${b}-bm PRIVATE gemmi_headers benchmark::benchmark)
     set_property(TARGET ${b}-bm PROPERTY RUNTIME_OUTPUT_DIRECTORY
                                              "${CMAKE_BINARY_DIR}/benchmarks")
     add_dependencies(check ${b}-bm)
@@ -416,6 +413,7 @@ if (USE_PYTHON)
           python/sf.cpp python/sym.cpp python/topo.cpp
           python/unitcell.cpp python/write.cpp
           $<TARGET_OBJECTS:gemmi_cpp>)
+  target_link_libraries(gemmi_py PRIVATE gemmi_headers)
   set_property(TARGET gemmi_py PROPERTY OUTPUT_NAME gemmi)
   if(CMAKE_CXX_FLAGS MATCHES "-Wshadow")
     target_compile_options(gemmi_py PRIVATE "-Wno-shadow")
@@ -444,7 +442,7 @@ if (BUILD_GEMMI_PROGRAM)
   # Is it useful to have the program location in gemmi-targets.cmake?
   install(TARGETS gemmi_prog EXPORT GemmiTargets)
 endif()
-install(TARGETS gemmi_cpp
+install(TARGETS gemmi_headers gemmi_cpp
         EXPORT GemmiTargets
         INCLUDES DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")