Remove Readline integration

The GNU Readline is licensed under the GNU GPL 3 and doesn't allow
linking with non-GPL compliant sofware, including PHP. This also
simplifies the Readline vs. libedit usage to make the build experience
as simple to use as possible.

Author: petk

.github/workflows/ci.yaml

@@ -97,7 +97,6 @@ jobs:
             libargon2-dev \
             libxslt1-dev \
             libcapstone-dev \
-            libreadline-dev \
             libedit-dev \
             libsnmp-dev \
             snmpd \

cmake/cmake/modules/FindReadline.cmake

@@ -22,21 +22,6 @@ cmake_dependent_option(
   OFF
 )
 
-cmake_dependent_option(
-  EXT_READLINE_LIBREADLINE
-  "Use the GNU Readline library instead of Editline"
-  OFF
-  "EXT_READLINE"
-  OFF
-)
-mark_as_advanced(EXT_READLINE_LIBREADLINE)
-
-add_feature_info(
-  "ext/readline with GNU Readline"
-  EXT_READLINE_LIBREADLINE
-  "GNU Readline library support instead of Editline"
-)
-
 if(NOT EXT_READLINE)
   return()
 endif()
@@ -64,145 +49,59 @@ if(HAVE_WNO_STRICT_PROTOTYPES_C)
   )
 endif()
 
-if(NOT EXT_READLINE_LIBREADLINE)
-  find_package(Editline)
-  set_package_properties(
-    Editline
-    PROPERTIES
-      TYPE REQUIRED
-      PURPOSE "Necessary to enable the readline extension."
-  )
+find_package(Editline)
+set_package_properties(
+  Editline
+  PROPERTIES
+    TYPE REQUIRED
+    PURPOSE "Necessary to enable the readline extension."
+)
 
-  target_link_libraries(php_readline PUBLIC Editline::Editline)
-
-  if(TARGET Editline::Editline)
-    check_library_exists(
-      Editline::Editline
-      rl_callback_read_char
-      ""
-      HAVE_RL_CALLBACK_READ_CHAR
-    )
-    check_library_exists(
-      Editline::Editline
-      rl_on_new_line
-      ""
-      HAVE_RL_ON_NEW_LINE
-    )
-    check_library_exists(
-      Editline::Editline
-      rl_completion_matches
-      ""
-      HAVE_RL_COMPLETION_MATCHES
-    )
-    check_library_exists(
-      Editline::Editline
-      history_list
-      ""
-      HAVE_HISTORY_LIST
-    )
-  endif()
+target_link_libraries(php_readline PUBLIC Editline::Editline)
 
-  set(
-    HAVE_LIBEDIT 1
-    CACHE INTERNAL "Whether Editline is used for readline extension"
+if(TARGET Editline::Editline)
+  check_library_exists(
+    Editline::Editline
+    rl_callback_read_char
+    ""
+    HAVE_RL_CALLBACK_READ_CHAR
   )
-
-  cmake_push_check_state(RESET)
-    set(CMAKE_REQUIRED_LIBRARIES Editline::Editline)
-    check_symbol_exists(
-      rl_erase_empty_line
-      editline/readline.h
-      HAVE_ERASE_EMPTY_LINE
-    )
-  cmake_pop_check_state()
-else()
-  message(
-    WARNING
-    "The GNU Readline library is licensed under the GNU GPL 3, which is not "
-    "compatible with the PHP license. The recommended library for using and "
-    "distributing the PHP 'readline' extension without limitations is libedit. "
-    "To build with libedit, remove the 'EXT_READLINE_LIBREADLINE', or set it "
-    "to 'OFF'."
+  check_library_exists(
+    Editline::Editline
+    rl_on_new_line
+    ""
+    HAVE_RL_ON_NEW_LINE
   )
-  find_package(Readline)
-  set_package_properties(
-    Readline
-    PROPERTIES
-      TYPE REQUIRED
-      PURPOSE "Necessary to enable the readline extension."
+  check_library_exists(
+    Editline::Editline
+    rl_completion_matches
+    ""
+    HAVE_RL_COMPLETION_MATCHES
   )
+  check_library_exists(
+    Editline::Editline
+    history_list
+    ""
+    HAVE_HISTORY_LIST
+  )
+endif()
 
-  target_link_libraries(php_readline PUBLIC Readline::Readline)
-
-  if(TARGET Readline::Readline)
-    # Sanity minimum version check if Readline library has the
-    # 'rl_pending_input' variable. The macOS systems might have an outdated
-    # forked Readline library installed on the system by default, which doesn't
-    # have this variable.
-    # See https://bugs.php.net/48608.
-    cmake_push_check_state(RESET)
-      set(CMAKE_REQUIRED_LIBRARIES Readline::Readline)
-
-      check_symbol_exists(
-        rl_pending_input
-        # The <readline/readline.h> is not self-contained header and some
-        # systems, like macOS, need <stdio.h> to have FILE type available.
-        "stdio.h;readline/readline.h"
-        _readline_have_rl_pending_input
-      )
-    cmake_pop_check_state()
-
-    if(NOT _readline_have_rl_pending_input)
-      message(
-        FATAL_ERROR
-        "Readline library check failed. Variable rl_pending_input missing. "
-        "This version of Readline installation is not supported. Try using "
-        "libedit instead (set EXT_READLINE_LIBREADLINE to 'OFF')."
-      )
-    endif()
-
-    check_library_exists(
-      Readline::Readline
-      rl_callback_read_char
-      ""
-      HAVE_RL_CALLBACK_READ_CHAR
-    )
-    check_library_exists(
-      Readline::Readline
-      rl_on_new_line
-      ""
-      HAVE_RL_ON_NEW_LINE
-    )
-    check_library_exists(
-      Readline::Readline
-      rl_completion_matches
-      ""
-      HAVE_RL_COMPLETION_MATCHES
-    )
-  endif()
+set(
+  HAVE_LIBEDIT 1
+  CACHE INTERNAL "Whether Editline is used for readline extension"
+)
 
-  set(
-    HAVE_HISTORY_LIST 1
-    CACHE INTERNAL "Whether Readline library has history_list"
-  )
-  set(
-    HAVE_LIBREADLINE 1
-    CACHE INTERNAL "Whether Readline is used for readline extension"
+cmake_push_check_state(RESET)
+  set(CMAKE_REQUIRED_LIBRARIES Editline::Editline)
+  check_symbol_exists(
+    rl_erase_empty_line
+    editline/readline.h
+    HAVE_ERASE_EMPTY_LINE
   )
+cmake_pop_check_state()
 
-  cmake_push_check_state(RESET)
-    set(CMAKE_REQUIRED_LIBRARIES Readline::Readline)
-    check_symbol_exists(
-      rl_erase_empty_line
-      # The <readline/readline.h> is not self-contained header and some systems,
-      # like macOS, need <stdio.h> to have FILE type available.
-      "stdio.h;readline/readline.h"
-      HAVE_ERASE_EMPTY_LINE
-    )
-  cmake_pop_check_state()
-endif()
 
-# TODO: Editline/Readline dependent libraries shouldn't be linked on this level.
+# TODO: Editline dependent libraries shouldn't be linked on this level.
 # Recheck if this is really needed. Either move to find modules or remove it.
 # Also, for example, Editline with Autoconf integration has even more thorough
 # dependencies checked in current version.

cmake/ext/readline/CMakeLists.txt

@@ -864,9 +864,6 @@
    https://www.sqlite.org/compile.html. */
 #cmakedefine PDO_SQLITE_OMIT_LOAD_EXTENSION 1
 
-/* Define to 1 if readline extension uses the 'readline' library. */
-#cmakedefine HAVE_LIBREADLINE 1
-
 /* Define to 1 if readline extension uses the 'libedit' library. */
 #cmakedefine HAVE_LIBEDIT 1
 

cmake/main/config.w32.cmake.h.in

@@ -961,9 +961,6 @@
 /* Define to 1 if you have the <LibraryManager.h> header file. */
 #cmakedefine HAVE_LIBRARYMANAGER_H 1
 
-/* Define to 1 if readline extension uses the 'readline' library. */
-#cmakedefine HAVE_LIBREADLINE 1
-
 /* Define to 1 if the PHP extension 'sodium' is available. */
 #cmakedefine HAVE_LIBSODIUMLIB 1