Remove support for the legacy Proj interface (Proj 4)

All major distributions have switched to newer versiosn long ago.

Author: joto

.github/actions/build-and-test/action.yml

@@ -22,8 +22,8 @@ runs:
           else
             CMAKE_OPTIONS="$CMAKE_OPTIONS -DWITH_LUAJIT=${LUAJIT_OPTION}"
           fi
-          if [ -n "$USE_PROJ_LIB" ]; then
-            CMAKE_OPTIONS="$CMAKE_OPTIONS -DUSE_PROJ_LIB=$USE_PROJ_LIB"
+          if [ -n "$WITH_PROJ" ]; then
+            CMAKE_OPTIONS="$CMAKE_OPTIONS -DWITH_PROJ=$WITH_PROJ"
           fi
           if [ -n "$CPP_VERSION" ]; then
             CMAKE_OPTIONS="$CMAKE_OPTIONS -DCMAKE_CXX_STANDARD=$CPP_VERSION"

.github/workflows/ci.yml

@@ -157,25 +157,6 @@ jobs:
       - uses: ./.github/actions/ubuntu-prerequisites
       - uses: ./.github/actions/build-and-test
 
-  ubuntu20-pg15-clang10-proj6:
-    runs-on: ubuntu-20.04
-
-    env:
-      CC: clang-10
-      CXX: clang++-10
-      LUA_VERSION: 5.3
-      LUAJIT_OPTION: OFF
-      POSTGRESQL_VERSION: 15
-      POSTGIS_VERSION: 3
-      USE_PROJ_LIB: 6
-      BUILD_TYPE: Debug
-      PSYCOPG: 2
-
-    steps:
-      - uses: actions/checkout@v4
-      - uses: ./.github/actions/ubuntu-prerequisites
-      - uses: ./.github/actions/build-and-test
-
   ubuntu20-pg15-clang10-noproj:
     runs-on: ubuntu-20.04
 
@@ -186,7 +167,7 @@ jobs:
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 15
       POSTGIS_VERSION: 3
-      USE_PROJ_LIB: off
+      WITH_PROJ: OFF
       BUILD_TYPE: Debug
       PSYCOPG: 2
 
@@ -205,7 +186,6 @@ jobs:
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 16
       POSTGIS_VERSION: 3
-      USE_PROJ_LIB: 6
       BUILD_TYPE: Debug
       PSYCOPG: 2
 
@@ -266,7 +246,7 @@ jobs:
       - uses: ./.github/actions/ubuntu-prerequisites
       - uses: ./.github/actions/build-and-test
 
-  ubuntu22-pg16-clang14-proj6:
+  ubuntu22-pg16-clang14-proj:
     runs-on: ubuntu-22.04
 
     env:
@@ -276,7 +256,6 @@ jobs:
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 16
       POSTGIS_VERSION: 3
-      USE_PROJ_LIB: 6
       BUILD_TYPE: Debug
       PSYCOPG: 2
 
@@ -295,7 +274,7 @@ jobs:
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 16
       POSTGIS_VERSION: 3
-      USE_PROJ_LIB: off
+      WITH_PROJ: OFF
       BUILD_TYPE: Debug
       PSYCOPG: 2
 
@@ -314,7 +293,6 @@ jobs:
       LUAJIT_OPTION: OFF
       POSTGRESQL_VERSION: 15
       POSTGIS_VERSION: 3
-      USE_PROJ_LIB: 6
       BUILD_TYPE: Debug
       PSYCOPG: 2
 

CMakeLists.txt

@@ -30,6 +30,7 @@ option(BUILD_TESTS    "Build test suite" OFF)
 option(BUILD_COVERAGE "Build with coverage" OFF)
 option(WITH_LUA       "Build with Lua support" ON)
 option(WITH_LUAJIT    "Build with LuaJIT support" OFF)
+option(WITH_PROJ      "Build with Projection support" ON)
 
 if (PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
     message(FATAL_ERROR "In-source builds are not allowed, please use a separate build directory like `mkdir build && cd build && cmake ..`")
@@ -57,8 +58,6 @@ option(EXTERNAL_PROTOZERO "Do not use the bundled protozero" OFF)
 option(EXTERNAL_FMT       "Do not use the bundled fmt"       OFF)
 option(EXTERNAL_CLI11     "Do not use the bundled CLI11"     OFF)
 
-set(USE_PROJ_LIB "auto" CACHE STRING "Which version of PROJ API to use: ('4', '6', 'off', or 'auto')")
-
 if (NOT WIN32 AND NOT APPLE)
     # No need for this path, just a workaround to make cmake work on all systems.
     # Without this we need the PostgreSQL server libraries installed.
@@ -222,42 +221,18 @@ find_package(OpenCV QUIET OPTIONAL_COMPONENTS core imgcodecs imgproc)
 
 set(LIBS ${Boost_LIBRARIES} ${PostgreSQL_LIBRARY} ${OSMIUM_LIBRARIES})
 
-if (USE_PROJ_LIB STREQUAL "off")
-    message(STATUS "Proj library disabled (because USE_PROJ_LIB is set to 'off').")
-else()
-    find_path(PROJ4_INCLUDE_DIR proj_api.h)
-    if (PROJ4_INCLUDE_DIR AND NOT USE_PROJ_LIB STREQUAL "6")
-        message(STATUS "Found proj_api.h")
-        find_library(PROJ_LIBRARY NAMES proj)
-        message(STATUS "Found Proj [API 4] ${PROJ_LIBRARY}")
-        add_definitions(-DHAVE_GENERIC_PROJ=4)
-        set(HAVE_PROJ4 1)
+if (WITH_PROJ)
+    find_path(PROJ6_INCLUDE_DIR proj.h)
+    find_library(PROJ_LIBRARY NAMES proj)
+    if (PROJ_LIBRARY)
+        message(STATUS "Found Proj ${PROJ_LIBRARY}")
+        add_definitions(-DHAVE_GENERIC_PROJ=6)
+        set(HAVE_PROJ6 1)
         list(APPEND LIBS ${PROJ_LIBRARY})
-        include_directories(SYSTEM ${PROJ4_INCLUDE_DIR})
-    elseif (NOT USE_PROJ_LIB STREQUAL "4")
-        find_path(PROJ6_INCLUDE_DIR proj.h)
-        find_library(PROJ_LIBRARY NAMES proj)
-        if (PROJ_LIBRARY)
-            message(STATUS "Found Proj [API 6] ${PROJ_LIBRARY}")
-            add_definitions(-DHAVE_GENERIC_PROJ=6)
-            set(HAVE_PROJ6 1)
-            list(APPEND LIBS ${PROJ_LIBRARY})
-            include_directories(SYSTEM ${PROJ6_INCLUDE_DIR})
-        else()
-            message(STATUS "Proj library not found.")
-            message(STATUS "    Only Mercartor and WGS84 projections will be available.")
-        endif()
+        include_directories(SYSTEM ${PROJ6_INCLUDE_DIR})
     endif()
 endif()
 
-if (USE_PROJ_LIB STREQUAL "4" AND NOT HAVE_PROJ4)
-    message(FATAL_ERROR "USE_PROJ_LIB was set to '4', but PROJ version 4 API not found")
-endif()
-
-if (USE_PROJ_LIB STREQUAL "6" AND NOT HAVE_PROJ6)
-    message(FATAL_ERROR "USE_PROJ_LIB was set to '6', but PROJ version 6 API not found")
-endif()
-
 if (LUAJIT_FOUND)
     list(APPEND LIBS ${LUAJIT_LIBRARIES})
 elseif (LUA_FOUND)

README.md

@@ -171,21 +171,9 @@ Note that `Debug` builds will be much slower than release build. For production
 ### Using the PROJ library
 
 Osm2pgsql has builtin support for the Latlong (WGS84, EPSG:4326) and the
-WebMercator (EPSG:3857) projection. If you need other projections you have to
-compile with the PROJ library.
-
-Both the older API (PROJ version 4) and the newer API (PROJ version 6.1 and
-above) are supported. Usually the CMake configuration will find a suitable
-version and use it automatically, but you can set the `USE_PROJ_LIB` CMake
-cache variable to choose between the following behaviours:
-
-* `4`: Look for PROJ library with API version 4. If it is not found, stop with
-  error.
-* `6`: Look for PROJ library with API version 6. If it is not found, stop with
-  error.
-* `off`: Build without PROJ library.
-* `auto`: Choose API 4 if available, otherwise API 6. If both are not available
-  build without PROJ library. (This is the default.)
+WebMercator (EPSG:3857) projection. Other projections are supported through
+the [Proj library](https://proj.org/) which is used by default. Set the CMake
+option `WITH_PROJ` to `OFF` to disable use of that library.
 
 ## Using LuaJIT
 

src/CMakeLists.txt

@@ -72,13 +72,7 @@ endif()
 
 target_sources(osm2pgsql_lib PRIVATE ${PROJECT_BINARY_DIR}/src/version.cpp)
 
-if (HAVE_PROJ4)
-    target_sources(osm2pgsql_lib PRIVATE reprojection-generic-proj4.cpp)
-    if (NOT MSVC)
-        set_source_files_properties(reprojection-generic-proj4.cpp
-            PROPERTIES COMPILE_FLAGS -Wno-deprecated-declarations)
-    endif()
-elseif(HAVE_PROJ6)
+if (HAVE_PROJ6)
     target_sources(osm2pgsql_lib PRIVATE reprojection-generic-proj6.cpp)
 else()
     target_sources(osm2pgsql_lib PRIVATE reprojection-generic-none.cpp)

src/reprojection-generic-proj4.cpp

@@ -119,6 +119,6 @@ std::shared_ptr<reprojection> reprojection::make_generic_projection(int srs)
 
 std::string get_proj_version()
 {
-    return fmt::format("[API 6] {}", proj_info().version);
+    return fmt::format("{}", proj_info().version);
 }