Make PROJ the CMake project name

Allow both find_package(PROJ) and find_package(PROJ4).  More details
are in cmake/CMakeLists.txt.

7 files changed, 151 insertions, 62 deletions

diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 23be1f23..c790fa4a 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -1,9 +1,78 @@
-# proj-config.cmake for the install tree.  It's installed in
-# ${INSTALL_CMAKE_DIR} and @PROJECT_ROOT_DIR@ is the relative
-# path to the root from there.  (Note that the whole install tree can
-# be relocated.)
-file(RELATIVE_PATH PROJECT_ROOT_DIR
-  ${CMAKE_INSTALL_PREFIX}/${CMAKECONFIGDIR} ${CMAKE_INSTALL_PREFIX})
+# The old CMake PROJECT-NAME was PROJ4.
+set (PROJECT_LEGACY_NAME PROJ4)
+string (TOLOWER "${PROJECT_NAME}" PROJECT_NAME_LOWER)
+string (TOLOWER "${PROJECT_LEGACY_NAME}" PROJECT_LEGACY_LOWER)
+
+# Starting with version 7.0, we install config-style find package
+# files so that PROJ can be found with both
+#
+#   find_package(PROJ)
+#   find_package(PROJ4)
+#
+# Here are the details...  The command
+#
+#   find_package(PROJ)
+#
+# if successful, will define variables
+#
+#   PROJ_FOUND
+#   PROJ_VERSION
+#   PROJ_LIBRARIES = PROJ::proj
+#   PROJ_INCLUDE_DIRS
+#   etc
+#
+# and will define targets
+#
+#   PROJ::proj
+#   PROJ4::proj
+#
+# Similarly
+#
+#   find_package(PROJ4)
+#
+# if successful, will define variables
+#
+#   PROJ4_FOUND
+#   PROJ4_VERSION
+#   PROJ4_LIBRARIES = PROJ4::proj
+#   PROJ4_INCLUDE_DIRS
+#   etc
+#
+# and will define targets
+#
+#   PROJ::proj
+#   PROJ4::proj
+#
+# Note that targets PROJ::proj and PROJ4::proj are provided in both
+# cases.  However, no attempt is made to define both sets of variables
+# with the two find_package options.  Doing so would just lead to user
+# confusion.
+#
+# Because pre-7.0 versions of PROJ do not support find_package (PROJ)
+# and do not define a target PROJ::proj
+#
+#   find_package(PROJ4)
+#
+# (instead of PROJ) should be used in any development scenarios which
+# might involve (even indirectly) pre-7.0 versions of PROJ.
+#
+# At some future dates, find_package (PROJ4) will
+#
+#   define PROJ4_LIBRARIES = PROJ::proj
+#   give WARNING message suggesting migration to find_package(PROJ)
+#   be disallowed via the version checking code
+#
+# At some more distant date, the PROJ4::proj target will be retired.
+#
+# To support this change, the CACHE variables PROJ_CMAKE_SUBDIR (and
+# CMAKECONFIGDIR) is now the "Parent of directory to install cmake
+# config files into".
+#
+# All this messiness is confined to
+#
+#   cmake/CMakeLists.txt (this file)
+#   cmake/project-config.cmake.in
+#   cmake/project-config-version.cmake.in
 
 # Variables needed by ${PROJECT_NAME_LOWER}-config-version.cmake
 if (MSVC)
@@ -24,21 +93,36 @@ else ()
   set (CMAKE_CROSSCOMPILING_STR "OFF")
 endif ()
 
-string(TOLOWER "${PROJECT_NAME}" PROJECT_NAME_LOWER)
-configure_file(project-config.cmake.in project-config.cmake @ONLY)
-configure_file(project-config-version.cmake.in
-  project-config-version.cmake @ONLY)
-install(FILES
-  "${CMAKE_CURRENT_BINARY_DIR}/project-config.cmake"
-  DESTINATION "${CMAKECONFIGDIR}"
-  RENAME "${PROJECT_NAME_LOWER}-config.cmake")
-install(FILES
-  "${CMAKE_CURRENT_BINARY_DIR}/project-config-version.cmake"
-  DESTINATION "${CMAKECONFIGDIR}"
-  RENAME "${PROJECT_NAME_LOWER}-config-version.cmake")
-# Make information about the cmake targets (the library and the tools)
-# available.
-install(EXPORT targets
-  NAMESPACE ${PROJECT_NAME}::
-  FILE ${PROJECT_NAME_LOWER}-targets.cmake
-  DESTINATION "${CMAKECONFIGDIR}")
+foreach (PROJECT_VARIANT_NAME ${PROJECT_NAME} ${PROJECT_LEGACY_NAME})
+  string (TOLOWER "${PROJECT_VARIANT_NAME}" PROJECT_VARIANT_LOWER)
+  set (CMAKECONFIGSUBDIR "${CMAKECONFIGDIR}/${PROJECT_VARIANT_LOWER}")
+  # proj-config.cmake for the install tree.  It's installed in
+  # ${CMAKECONFIGSUBDIR} and @PROJECT_ROOT_DIR@ is the relative
+  # path to the root from there.  (Note that the whole install tree can
+  # be relocated.)
+  file (RELATIVE_PATH PROJECT_ROOT_DIR
+    ${CMAKE_INSTALL_PREFIX}/${CMAKECONFIGSUBDIR} ${CMAKE_INSTALL_PREFIX})
+  configure_file (project-config.cmake.in
+    project-${PROJECT_VARIANT_LOWER}-config.cmake @ONLY)
+  configure_file (project-config-version.cmake.in
+    project-${PROJECT_VARIANT_LOWER}-version.cmake @ONLY)
+  install(FILES
+    "${CMAKE_CURRENT_BINARY_DIR}/project-${PROJECT_VARIANT_LOWER}-config.cmake"
+    DESTINATION "${CMAKECONFIGSUBDIR}"
+    RENAME "${PROJECT_VARIANT_LOWER}-config.cmake")
+  install(FILES
+    "${CMAKE_CURRENT_BINARY_DIR}/project-${PROJECT_VARIANT_LOWER}-version.cmake"
+    DESTINATION "${CMAKECONFIGSUBDIR}"
+    RENAME "${PROJECT_VARIANT_LOWER}-config-version.cmake")
+  # Make information about the cmake targets (the library and the tools)
+  # available.
+  install(EXPORT targets
+    NAMESPACE ${PROJECT_NAME}::
+    FILE ${PROJECT_NAME_LOWER}-targets.cmake
+    DESTINATION "${CMAKECONFIGSUBDIR}")
+  install(EXPORT targets
+    NAMESPACE ${PROJECT_LEGACY_NAME}::
+    FILE ${PROJECT_LEGACY_LOWER}-targets.cmake
+    DESTINATION "${CMAKECONFIGSUBDIR}")
+endforeach ()
+
diff --git a/cmake/ProjConfig.cmake b/cmake/ProjConfig.cmake
index 9f1b4e44..661e6e4f 100644
--- a/cmake/ProjConfig.cmake
+++ b/cmake/ProjConfig.cmake
@@ -32,10 +32,10 @@ check_library_exists(m ceil "" HAVE_LIBM)
 set(PACKAGE "proj")
 set(PACKAGE_BUGREPORT "https://github.com/OSGeo/PROJ/issues")
 set(PACKAGE_NAME "PROJ")
-set(PACKAGE_STRING "PROJ ${${PROJECT_INTERN_NAME}_VERSION}")
+set(PACKAGE_STRING "PROJ ${${PROJECT_NAME}_VERSION}")
 set(PACKAGE_TARNAME "proj")
 set(PACKAGE_URL "https://proj.org")
-set(PACKAGE_VERSION "${${PROJECT_INTERN_NAME}_VERSION}")
+set(PACKAGE_VERSION "${${PROJECT_NAME}_VERSION}")
 
 # check if a second proj_config.h exists (created by ./configure)
 # as this is within CMake's C_INCLUDES / CXX_INCLUDES
diff --git a/cmake/ProjInstallPath.cmake b/cmake/ProjInstallPath.cmake
index e74519b1..4c63d658 100644
--- a/cmake/ProjInstallPath.cmake
+++ b/cmake/ProjInstallPath.cmake
@@ -30,7 +30,7 @@ if(UNIX)
   set(DEFAULT_DATA_SUBDIR ${CMAKE_INSTALL_DATAROOTDIR}/proj)
   set(DEFAULT_INCLUDE_SUBDIR ${CMAKE_INSTALL_INCLUDEDIR})
   set(DEFAULT_DOC_SUBDIR ${CMAKE_INSTALL_DOCDIR})
-  set(DEFAULT_CMAKE_SUBDIR ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME_LOWER})
+  set(DEFAULT_CMAKE_SUBDIR ${CMAKE_INSTALL_LIBDIR}/cmake)
 else()
   # Common locations for Unix and Mac OS X
   set(DEFAULT_BIN_SUBDIR bin)
@@ -39,7 +39,7 @@ else()
   set(DEFAULT_DOC_SUBDIR doc/proj)
   set(DEFAULT_INCLUDE_SUBDIR include)
   set(DEFAULT_DOC_SUBDIR share/doc/proj)
-  set(DEFAULT_CMAKE_SUBDIR lib/cmake/${PROJECT_NAME_LOWER})
+  set(DEFAULT_CMAKE_SUBDIR lib/cmake)
 endif()
 
 # Locations are changeable by user to customize layout of PROJ installation
@@ -55,7 +55,7 @@ set(PROJ_DATA_SUBDIR ${DEFAULT_DATA_SUBDIR} CACHE STRING
 set(PROJ_DOC_SUBDIR ${DEFAULT_DOC_SUBDIR} CACHE STRING
   "Subdirectory where doc will be installed")
 set(PROJ_CMAKE_SUBDIR ${DEFAULT_CMAKE_SUBDIR} CACHE STRING
-  "Subdirectory where cmake proj-config file will be installed")
+  "Parent of subdirectory where cmake proj-config file will be installed")
 
 # Mark *DIR variables as advanced and dedicated to use by power-users only.
 mark_as_advanced(
diff --git a/cmake/ProjUtilities.cmake b/cmake/ProjUtilities.cmake
index d63cedac..447276ff 100644
--- a/cmake/ProjUtilities.cmake
+++ b/cmake/ProjUtilities.cmake
@@ -98,17 +98,17 @@ function(proj_target_output_name TARGET_NAME OUTPUT_NAME)
     message(SEND_ERROR "Error, the variable TARGET_NAME is not defined!")
   endif()
 
-  if(NOT DEFINED ${PROJECT_INTERN_NAME}_VERSION)
+  if(NOT DEFINED ${PROJECT_NAME}_VERSION)
     message(SEND_ERROR
-      "Error, the variable ${${PROJECT_INTERN_NAME}_VERSION} is not defined!")
+      "Error, the variable ${${PROJECT_NAME}_VERSION} is not defined!")
   endif()
 
   # On Windows, ABI version is specified using binary file name suffix.
   # On Unix, suffix is empty and SOVERSION is used instead.
   if(WIN32)
-    string(LENGTH "${${PROJECT_INTERN_NAME}_ABI_VERSION}" abilen)
+    string(LENGTH "${${PROJECT_NAME}_ABI_VERSION}" abilen)
     if(abilen GREATER 0)
-      set(SUFFIX "_${${PROJECT_INTERN_NAME}_ABI_VERSION}")
+      set(SUFFIX "_${${PROJECT_NAME}_ABI_VERSION}")
     endif()
   endif()
 
diff --git a/cmake/ProjVersion.cmake b/cmake/ProjVersion.cmake
index 5614d44d..d64795a8 100644
--- a/cmake/ProjVersion.cmake
+++ b/cmake/ProjVersion.cmake
@@ -27,27 +27,27 @@ macro(proj_version)
     ${ARGN})
 
   # Set version components
-  set(${PROJECT_INTERN_NAME}_VERSION_MAJOR ${THIS_VERSION_MAJOR})
-  set(${PROJECT_INTERN_NAME}_VERSION_MINOR ${THIS_VERSION_MINOR})
-  set(${PROJECT_INTERN_NAME}_VERSION_PATCH ${THIS_VERSION_PATCH})
+  set(${PROJECT_NAME}_VERSION_MAJOR ${THIS_VERSION_MAJOR})
+  set(${PROJECT_NAME}_VERSION_MINOR ${THIS_VERSION_MINOR})
+  set(${PROJECT_NAME}_VERSION_PATCH ${THIS_VERSION_PATCH})
 
   # Set VERSION string
-  set(${PROJECT_INTERN_NAME}_VERSION
-    "${${PROJECT_INTERN_NAME}_VERSION_MAJOR}.\
-${${PROJECT_INTERN_NAME}_VERSION_MINOR}.\
-${${PROJECT_INTERN_NAME}_VERSION_PATCH}")
+  set(${PROJECT_NAME}_VERSION
+    "${${PROJECT_NAME}_VERSION_MAJOR}.\
+${${PROJECT_NAME}_VERSION_MINOR}.\
+${${PROJECT_NAME}_VERSION_PATCH}")
 
   # Set ABI version string used to name binary output
   # On Windows, ABI version is specified using binary file name suffix.
   if(WIN32)
-    set(${PROJECT_INTERN_NAME}_ABI_VERSION
-      "${${PROJECT_INTERN_NAME}_VERSION_MAJOR}_\
-${${PROJECT_INTERN_NAME}_VERSION_MINOR}")
+    set(${PROJECT_NAME}_ABI_VERSION
+      "${${PROJECT_NAME}_VERSION_MAJOR}_\
+${${PROJECT_NAME}_VERSION_MINOR}")
   endif()
 
   message(STATUS "")
-  boost_report_value(${PROJECT_INTERN_NAME}_VERSION)
+  boost_report_value(${PROJECT_NAME}_VERSION)
   if(WIN32)
-    boost_report_value(${PROJECT_INTERN_NAME}_ABI_VERSION)
+    boost_report_value(${PROJECT_NAME}_ABI_VERSION)
   endif()
 endmacro()
diff --git a/cmake/project-config-version.cmake.in b/cmake/project-config-version.cmake.in
index 0d25a7c3..c2d98b39 100644
--- a/cmake/project-config-version.cmake.in
+++ b/cmake/project-config-version.cmake.in
@@ -1,4 +1,4 @@
-# Version checking for @PROJECT_NAME@
+# Version checking for @PROJECT_VARIANT_NAME@
 
 set (PACKAGE_VERSION "@PROJ_VERSION@")
 set (PACKAGE_VERSION_MAJOR "@PROJ_VERSION_MAJOR@")
@@ -22,12 +22,12 @@ else ()
   set (CMAKE_CROSSCOMPILING_STR "OFF")
 endif ()
 
-if (NOT PACKAGE_FIND_NAME STREQUAL "@PROJECT_NAME@")
+if (NOT PACKAGE_FIND_NAME STREQUAL "@PROJECT_VARIANT_NAME@")
   # Check package name (in particular, because of the way cmake finds
   # package config files, the capitalization could easily be "wrong").
   # This is necessary to ensure that the automatically generated
   # variables, e.g., <package>_FOUND, are consistently spelled.
-  set (REASON "package = @PROJECT_NAME@, NOT ${PACKAGE_FIND_NAME}")
+  set (REASON "package = @PROJECT_VARIANT_NAME@, NOT ${PACKAGE_FIND_NAME}")
   set (PACKAGE_VERSION_UNSUITABLE TRUE)
 elseif (NOT (APPLE OR (NOT DEFINED CMAKE_SIZEOF_VOID_P) OR
       CMAKE_SIZEOF_VOID_P EQUAL @CMAKE_SIZEOF_VOID_P@))
diff --git a/cmake/project-config.cmake.in b/cmake/project-config.cmake.in
index fcb0698f..5ee5c0f9 100644
--- a/cmake/project-config.cmake.in
+++ b/cmake/project-config.cmake.in
@@ -1,31 +1,36 @@
 # Configure @PROJECT_NAME@
 #
 # Set
-#  @PROJECT_NAME@_FOUND = 1
-#  @PROJECT_NAME@_INCLUDE_DIRS = /usr/local/include
-#  @PROJECT_NAME@_LIBRARIES = proj
-#  @PROJECT_NAME@_LIBRARY_DIRS = /usr/local/lib
-#  @PROJECT_NAME@_BINARY_DIRS = /usr/local/bin
-#  @PROJECT_NAME@_VERSION = 4.9.1 (for example)
+#  @PROJECT_VARIANT_NAME@_FOUND = 1
+#  @PROJECT_VARIANT_NAME@_INCLUDE_DIRS = /usr/local/include
+#  @PROJECT_VARIANT_NAME@_LIBRARIES = @PROJECT_VARIANT_NAME@::proj
+#  @PROJECT_VARIANT_NAME@_LIBRARY_DIRS = /usr/local/lib
+#  @PROJECT_VARIANT_NAME@_BINARY_DIRS = /usr/local/bin
+#  @PROJECT_VARIANT_NAME@_VERSION = 4.9.1 (for example)
 
 message (STATUS "Reading ${CMAKE_CURRENT_LIST_FILE}")
-# @PROJECT_NAME@_VERSION is set by version file
+# @PROJECT_VARIANT_NAME@_VERSION is set by version file
 message (STATUS
-  "@PROJECT_NAME@ configuration, version ${@PROJECT_NAME@_VERSION}")
+  "@PROJECT_VARIANT_NAME@ configuration, \
+version ${@PROJECT_VARIANT_NAME@_VERSION}")
 
 # Tell the user project where to find our headers and libraries
 get_filename_component (_DIR ${CMAKE_CURRENT_LIST_FILE} PATH)
 get_filename_component (_ROOT "${_DIR}/@PROJECT_ROOT_DIR@" ABSOLUTE)
-set (@PROJECT_NAME@_INCLUDE_DIRS "${_ROOT}/@INCLUDEDIR@")
-set (@PROJECT_NAME@_LIBRARY_DIRS "${_ROOT}/@LIBDIR@")
-set (@PROJECT_NAME@_BINARY_DIRS "${_ROOT}/@BINDIR@")
+set (@PROJECT_VARIANT_NAME@_INCLUDE_DIRS "${_ROOT}/@INCLUDEDIR@")
+set (@PROJECT_VARIANT_NAME@_LIBRARY_DIRS "${_ROOT}/@LIBDIR@")
+set (@PROJECT_VARIANT_NAME@_BINARY_DIRS "${_ROOT}/@BINDIR@")
 
-set (@PROJECT_NAME@_LIBRARIES @PROJECT_NAME@::proj)
+set (@PROJECT_VARIANT_NAME@_LIBRARIES @PROJECT_VARIANT_NAME@::proj)
 # Read in the exported definition of the library
 include ("${_DIR}/@PROJECT_NAME_LOWER@-targets.cmake")
+include ("${_DIR}/@PROJECT_LEGACY_LOWER@-targets.cmake")
 
 unset (_ROOT)
 unset (_DIR)
 
-# For backward compatibility with old releases of libgeotiff
-set (@PROJECT_NAME@_INCLUDE_DIR ${@PROJECT_NAME@_INCLUDE_DIRS})
+if ("@PROJECT_VARIANT_NAME@" STREQUAL "PROJ4")
+  # For backward compatibility with old releases of libgeotiff
+  set (@PROJECT_VARIANT_NAME@_INCLUDE_DIR
+    ${@PROJECT_VARIANT_NAME@_INCLUDE_DIRS})
+endif ()