Add support for tribits_add_library( ... HEADERONLY ... )

ToDo: We need to check that the SOURCES var is empty if HEADERONLY is passed in. Current, we just ignore SOURCES. Signed-off-by: Roscoe A. Bartlett <[email protected]>
bartlettroscoe · Feb 21, 2025 · 4dcd271 · 4dcd271
1 parent a3ddcf6
commit 4dcd271
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diff --git a/tribits/CHANGELOG.md b/tribits/CHANGELOG.md
@@ -2,6 +2,12 @@
 ChangeLog for TriBITS
 ----------------------------------------
 
+## 2025-02-17:
+
+* **Added:** Added support for header-only libraries with
+  `tribits_add_library()` with new keyword `HEADERONLY`.  See
+  updated documentation.
+
 ## 2024-10-08:
 
 * **Changed:** The TriBITS framework find operation for

diff --git a/tribits/core/package_arch/TribitsAddLibrary.cmake b/tribits/core/package_arch/TribitsAddLibrary.cmake
@@ -35,7 +35,7 @@ include(TribitsSetAndIncDirs)
 #     [HEADERS <h0> <h1> ...]
 #     [HEADERS_INSTALL_SUBDIR <headerssubdir>]
 #     [NOINSTALLHEADERS <nih0> <hih1> ...]
-#     [SOURCES <src0> <src1> ...]
+#     [SOURCES <src0> <src1> ...|HEADERONLY]
 #     [DEPLIBS <deplib0> <deplib1> ...]
 #     [IMPORTEDLIBS <ideplib0> <ideplib1> ...]
 #     [STATIC|SHARED]
@@ -150,6 +150,12 @@ include(TribitsSetAndIncDirs)
 #     if, for example, ``-fPIC`` is specified).  So be careful to use
 #     ``STATIC`` in all downstream libraries!
 #
+#   ``HEADERONLY``
+#
+#     If passed in, then the ``<libTargetName>`` library target will be
+#     declared ``INTERFACE`` and the ``SOURCES`` argument must be empty.  This
+#     is used to create a header-only library.
+#
 #   ``TESTONLY``
 #
 #     If passed in, then ``<libTargetName>`` will **not** be added to
@@ -319,7 +325,7 @@ function(tribits_add_library  LIBRARY_NAME_IN)
     #prefix
     PARSE
     #Options    
-    "STATIC;SHARED;TESTONLY;NO_INSTALL_LIB_OR_HEADERS;CUDALIBRARY"
+    "STATIC;SHARED;HEADERONLY;TESTONLY;NO_INSTALL_LIB_OR_HEADERS;CUDALIBRARY"
     #one_value_keywords
     ""
     #mulit_value_keywords
@@ -369,27 +375,39 @@ function(tribits_add_library  LIBRARY_NAME_IN)
       add_definitions(${PARSE_DEFINES})
     endif()
 
+    if (PARSE_HEADERONLY)
+      set(tribitsAddLibraryIncludeDirsMode "INTERFACE")
+    else()
+      set(tribitsAddLibraryIncludeDirsMode "PUBLIC")
+    endif()
+
+    set(STATIC_KEYWORD "")
+    set(SHARED_KEYWORD "")
+
     if (PARSE_STATIC)
       set(STATIC_KEYWORD "STATIC")
-    else()
-      set(STATIC_KEYWORD "")
     endif()
 
     if (PARSE_SHARED)
       set(SHARED_KEYWORD "SHARED")
-    else()
-      set(SHARED_KEYWORD "")
     endif()
 
     if (NOT PARSE_CUDALIBRARY)
-      add_library(
-        ${LIBRARY_NAME}
-        ${STATIC_KEYWORD}
-        ${SHARED_KEYWORD}
-        ${PARSE_HEADERS}
-        ${PARSE_NOINSTALLHEADERS}
-        ${PARSE_SOURCES}
-        )
+      if (PARSE_HEADERONLY)
+        add_library(
+          ${LIBRARY_NAME}
+	  INTERFACE
+          )
+      else()
+        add_library(
+          ${LIBRARY_NAME}
+          ${STATIC_KEYWORD}
+          ${SHARED_KEYWORD}
+          ${PARSE_HEADERS}
+          ${PARSE_NOINSTALLHEADERS}
+          ${PARSE_SOURCES}
+          )
+      endif()
     else()
       cuda_add_library(
         ${LIBRARY_NAME}
@@ -433,30 +451,35 @@ function(tribits_add_library  LIBRARY_NAME_IN)
 
     # DEPLIBS
     foreach(depLib ${PARSE_DEPLIBS})
-      target_link_libraries(${LIBRARY_NAME} PUBLIC "${LIBRARY_NAME_PREFIX}${depLib}")
+      target_link_libraries(${LIBRARY_NAME}
+	${tribitsAddLibraryIncludeDirsMode} "${LIBRARY_NAME_PREFIX}${depLib}")
     endforeach()
     # ${PACKAGE_NAME}_LIBRARIES
-    target_link_libraries(${LIBRARY_NAME} PUBLIC ${${PACKAGE_NAME}_LIBRARIES})
+    target_link_libraries(${LIBRARY_NAME}
+      ${tribitsAddLibraryIncludeDirsMode} ${${PACKAGE_NAME}_LIBRARIES})
     # ${PACKAGE_NAME}_LIB_ENABLED_DEPENDENCIES
     foreach(depPkg IN LISTS ${PACKAGE_NAME}_LIB_ENABLED_DEPENDENCIES)
-      target_link_libraries(${LIBRARY_NAME} PUBLIC ${depPkg}::all_libs)
+      target_link_libraries(${LIBRARY_NAME}
+	${tribitsAddLibraryIncludeDirsMode} ${depPkg}::all_libs)
     endforeach()
     # ${PACKAGE_NAME}_TEST_ENABLED_DEPENDENCIES (TESTONLY lib)
     if (PARSE_TESTONLY)
       foreach(depPkg IN LISTS ${PACKAGE_NAME}_TEST_ENABLED_DEPENDENCIES)
-        target_link_libraries(${LIBRARY_NAME} PUBLIC ${depPkg}::all_libs)
+        target_link_libraries(${LIBRARY_NAME}
+	  ${tribitsAddLibraryIncludeDirsMode} ${depPkg}::all_libs)
       endforeach()
     endif()
     # IMPORTEDLIBS
     foreach(importedLib ${PARSE_IMPORTEDLIBS})
-      target_link_libraries(${LIBRARY_NAME} PUBLIC "${importedLib}")
+      target_link_libraries(${LIBRARY_NAME}
+	${tribitsAddLibraryIncludeDirsMode} "${importedLib}")
     endforeach()
 
     # ToDo: #63: Above, allow for other link visibilities other than 'PUBLIC'!
 
     if (${PROJECT_NAME}_CXX_STANDARD_FEATURE)
-      target_compile_features(${LIBRARY_NAME} PUBLIC
-        "${${PROJECT_NAME}_CXX_STANDARD_FEATURE}")
+      target_compile_features(${LIBRARY_NAME}
+	${tribitsAddLibraryIncludeDirsMode} "${${PROJECT_NAME}_CXX_STANDARD_FEATURE}")
     endif()
 
     # Add to the install target
@@ -510,7 +533,8 @@ function(tribits_add_library  LIBRARY_NAME_IN)
     foreach (includeDir IN LISTS INCLUDE_DIRS_CURRENT)
       list(APPEND buildInterfaceIncludeDirs "$<BUILD_INTERFACE:${includeDir}>")
     endforeach()
-    target_include_directories( ${LIBRARY_NAME} PUBLIC ${buildInterfaceIncludeDirs} )
+    target_include_directories( ${LIBRARY_NAME}
+      ${tribitsAddLibraryIncludeDirsMode} ${buildInterfaceIncludeDirs} )
 
     # Add ALIAS library <PackageName>::<libname>
     add_library(${PACKAGE_NAME}::${LIBRARY_NAME} ALIAS ${LIBRARY_NAME})

diff --git a/tribits/examples/TribitsExampleProject/packages/mixed_lang/src/CMakeLists.txt b/tribits/examples/TribitsExampleProject/packages/mixed_lang/src/CMakeLists.txt
@@ -1,5 +1,6 @@
 tribits_configure_file(${PACKAGE_NAME}_config.h)
 
+add_subdirectory(vector)
 
 set(HEADERS "")
 set(SOURCES "")
@@ -26,4 +27,5 @@ tribits_add_library(
   mixedlang
   HEADERS ${HEADERS}
   SOURCES ${SOURCES}
+  DEPLIBS mixedlang_vector
   )
diff --git a/tribits/examples/TribitsExampleProject/packages/mixed_lang/src/vector/CMakeLists.txt b/tribits/examples/TribitsExampleProject/packages/mixed_lang/src/vector/CMakeLists.txt
@@ -0,0 +1,8 @@
+tribits_include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+
+tribits_add_library(
+  mixedlang_vector
+  HEADERONLY
+  HEADERS Vector_Lite.hh
+  HEADERS_INSTALL_SUBDIR vector
+  )
diff --git a/...ct/packages/mixed_lang/src/Vector_Lite.hh → ...ages/mixed_lang/src/vector/Vector_Lite.hh b/...ct/packages/mixed_lang/src/Vector_Lite.hh → ...ages/mixed_lang/src/vector/Vector_Lite.hh