Add shared SAPIs and enable position independent code globally

Changes:
* Position independent code is for now unconditionally enabled globally
* Apache PHP module output filename named to mod_php
* Added phpdbg pkg-config file for its shared library/module for the
  sake of consistency with embed and php as a whole
* Added shared embed SAPI

For the time being, this simplifies building shared apache2handler,
embed and phpdbg SAPIs that require the position independent code.

While there is this rule of a thumb that position independent code
enabled on executables slightly decreases performance, the usability
benefits outweight this issue in this case. At least until a better
solution can be integrated here.

The conditional check for CMAKE_POSITION_INDEPENDENT_CODE is removed
because now it seems to be completely redundant in any case. The
upstream issue is different because there the PIC is forcefully disabled
in configure.ac on some 32-bit machines and that's why it doesn't work.

Author: petk

bin/check-cmake.php

@@ -152,6 +152,7 @@ function getProjectModules(): array
         'CheckLanguage' => ['check_language'],
         'CheckLibraryExists' => ['check_library_exists'],
         'CheckLinkerFlag' => ['check_linker_flag'],
+        'CheckPIESupported' => ['check_pie_supported'],
         'CheckPrototypeDefinition' => ['check_prototype_definition'],
         'CheckSourceCompiles' => ['check_source_compiles'],
         'CheckSourceRuns' => ['check_source_runs'],

cmake/cmake/modules/PHP/PositionIndependentCode.cmake

@@ -4,17 +4,31 @@
 Check whether to enable the `POSITION_INDEPENDENT_CODE` or not for all targets.
 The SHARED and MODULE targets have PIC enabled regardless of this option.
 
+TODO: This unconditionally enables position independent code globally, to be
+able to build shared apache2handler, embed, and phpdbg SAPIs. Probably could be
+fine tuned in the future better but it can exponentially complicate the build
+system code or the build usability.
+
 https://cmake.org/cmake/help/latest/variable/CMAKE_POSITION_INDEPENDENT_CODE.html
 #]=============================================================================]
 
 include_guard(GLOBAL)
 
-if(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND CMAKE_SIZEOF_VOID_P EQUAL 4)
-  # On 32-bit *nix (Linux and FreeBSD at least) when using Clang, the PIC is
-  # required.
+block()
+  include(CheckPIESupported)
+  check_pie_supported(OUTPUT_VARIABLE output)
+  if(NOT CMAKE_C_LINK_PIE_SUPPORTED)
+    message(
+      WARNING
+      "Position independent executable (PIE) is not supported at link time: "
+      "${output}.\n"
+      "PIE link options will not be passed to linker."
+    )
+  endif()
+endblock()
+
+if(NOT DEFINED CMAKE_POSITION_INDEPENDENT_CODE)
   set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-else()
-  set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
 endif()
 
 message(

cmake/sapi/apache2handler/CMakeLists.txt

@@ -58,7 +58,7 @@ target_sources(
 set_target_properties(
   php_sapi_apache2handler
   PROPERTIES
-    OUTPUT_NAME apache
+    OUTPUT_NAME mod_${PHP_PROGRAM_PREFIX}php${PHP_PROGRAM_SUFFIX}
 )
 
 target_compile_definitions(
@@ -132,5 +132,8 @@ endif()
 
 install(
   TARGETS php_sapi_apache2handler
-  DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY
+    DESTINATION ${Apache_LIBEXECDIR}
+  RUNTIME
+    DESTINATION ${Apache_LIBEXECDIR}
 )

cmake/sapi/embed/CMakeLists.txt

@@ -34,38 +34,39 @@ endif()
 add_library(php_sapi_embed STATIC)
 add_library(PHP::sapi::embed ALIAS php_sapi_embed)
 
+add_library(php_sapi_embed_shared SHARED)
+add_library(PHP::sapi::embed_shared ALIAS php_sapi_embed_shared)
+
 target_sources(
   php_sapi_embed
-  PRIVATE
-    php_embed.c
   PUBLIC
     FILE_SET HEADERS
       FILES
         php_embed.h
 )
 
-target_link_libraries(
-  php_sapi_embed
-  PRIVATE
-    $<BUILD_INTERFACE:PHP::sapi>
-)
+foreach(target IN ITEMS php_sapi_embed php_sapi_embed_shared)
+  target_sources(${target} PRIVATE php_embed.c)
 
-target_compile_definitions(php_sapi_embed PRIVATE ZEND_ENABLE_STATIC_TSRMLS_CACHE)
+  target_link_libraries(${target} PRIVATE $<BUILD_INTERFACE:PHP::sapi>)
 
-set_target_properties(
-  php_sapi_embed
-  PROPERTIES
-    OUTPUT_NAME libphp
-    ENABLE_EXPORTS TRUE # TODO: Check if there's a better solution.
-    PHP_CLI TRUE
-)
+  target_compile_definitions(${target} PRIVATE ZEND_ENABLE_STATIC_TSRMLS_CACHE)
+
+  set_target_properties(
+    ${target}
+    PROPERTIES
+      OUTPUT_NAME libphp
+      ENABLE_EXPORTS TRUE # TODO: Check if there's a better solution.
+      PHP_CLI TRUE
+  )
+endforeach()
 
 # Configure pkg-config php-embed.pc metadata file.
 include(PHP/PkgConfig)
 php_pkgconfig_generate_pc(
   php-embed.pc.in
   php-embed.pc
-  TARGET PHP::sapi::embed
+  TARGET PHP::sapi::embed_shared
   VARIABLES
     prefix "$<INSTALL_PREFIX>"
     exec_prefix "$<INSTALL_PREFIX>"
@@ -83,7 +84,9 @@ php_pkgconfig_generate_pc(
 )
 
 install(
-  TARGETS php_sapi_embed
+  TARGETS php_sapi_embed php_sapi_embed_shared
+  ARCHIVE
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}
   RUNTIME
     DESTINATION ${CMAKE_INSTALL_LIBDIR}
   LIBRARY

cmake/sapi/phpdbg/CMakeLists.txt

@@ -100,47 +100,68 @@ endif()
 # Executable and library.
 ################################################################################
 
-set(phpdbgSources
-  phpdbg_bp.c
-  phpdbg_break.c
-  phpdbg_btree.c
-  phpdbg_cmd.c
-  phpdbg_frame.c
-  phpdbg_help.c
-  phpdbg_info.c
-  phpdbg_io.c
-  phpdbg_lexer.c
-  phpdbg_list.c
-  phpdbg_out.c
-  phpdbg_parser.c
-  phpdbg_print.c
-  phpdbg.stub.php
-  phpdbg_prompt.c
-  phpdbg_set.c
-  phpdbg_sigsafe.c
-  phpdbg_utils.c
-  phpdbg_watch.c
-  $<$<PLATFORM_ID:Windows>:phpdbg_win.c>
-  phpdbg.c
-)
-
-add_executable(php_sapi_phpdbg ${phpdbgSources})
+add_executable(php_sapi_phpdbg)
 add_executable(PHP::sapi::phpdbg ALIAS php_sapi_phpdbg)
 
-target_compile_definitions(
-  php_sapi_phpdbg
-  PRIVATE
-    ZEND_ENABLE_STATIC_TSRMLS_CACHE
-    $<$<PLATFORM_ID:Windows>:YY_NO_UNISTD_H>
-    $<IF:$<BOOL:${PHP_SAPI_PHPDBG_DEBUG}>,PHPDBG_DEBUG=1,PHPDBG_DEBUG=0>
-)
+if(PHP_SAPI_PHPDBG_SHARED)
+  add_library(php_sapi_phpdbg_shared SHARED)
+  add_library(PHP::sapi::phpdbg_shared ALIAS php_sapi_phpdbg_shared)
+endif()
 
-target_link_libraries(
-  php_sapi_phpdbg
-  PRIVATE
-    $<BUILD_INTERFACE:PHP::sapi>
-    $<$<PLATFORM_ID:Windows>:ws2_32;user32>
-)
+foreach(target IN ITEMS php_sapi_phpdbg php_sapi_phpdbg_shared)
+  if(NOT TARGET ${target})
+    continue()
+  endif()
+
+  target_sources(
+    ${target}
+    PRIVATE
+      phpdbg_bp.c
+      phpdbg_break.c
+      phpdbg_btree.c
+      phpdbg_cmd.c
+      phpdbg_frame.c
+      phpdbg_help.c
+      phpdbg_info.c
+      phpdbg_io.c
+      phpdbg_lexer.c
+      phpdbg_list.c
+      phpdbg_out.c
+      phpdbg_parser.c
+      phpdbg_print.c
+      phpdbg.stub.php
+      phpdbg_prompt.c
+      phpdbg_set.c
+      phpdbg_sigsafe.c
+      phpdbg_utils.c
+      phpdbg_watch.c
+      $<$<PLATFORM_ID:Windows>:phpdbg_win.c>
+      phpdbg.c
+  )
+
+  target_compile_definitions(
+    ${target}
+    PRIVATE
+      ZEND_ENABLE_STATIC_TSRMLS_CACHE
+      $<$<PLATFORM_ID:Windows>:YY_NO_UNISTD_H>
+      $<IF:$<BOOL:${PHP_SAPI_PHPDBG_DEBUG}>,PHPDBG_DEBUG=1,PHPDBG_DEBUG=0>
+  )
+
+  target_link_libraries(
+    ${target}
+    PRIVATE
+      $<BUILD_INTERFACE:PHP::sapi>
+      $<$<PLATFORM_ID:Windows>:ws2_32;user32>
+  )
+
+  set_target_properties(
+    ${target}
+    PROPERTIES
+      OUTPUT_NAME ${PHP_PROGRAM_PREFIX}phpdbg${PHP_PROGRAM_SUFFIX}
+      ENABLE_EXPORTS TRUE # TODO: Check if there's a better solution.
+      PHP_CLI TRUE
+  )
+endforeach()
 
 target_link_options(
   php_sapi_phpdbg
@@ -152,10 +173,16 @@ set_target_properties(
   php_sapi_phpdbg
   PROPERTIES
     OUTPUT_NAME ${PHP_PROGRAM_PREFIX}phpdbg${PHP_PROGRAM_SUFFIX}
-    ENABLE_EXPORTS TRUE # TODO: Check if there's a better solution.
-    PHP_CLI TRUE
 )
 
+if(TARGET php_sapi_phpdbg_shared)
+  set_target_properties(
+    php_sapi_phpdbg_shared
+    PROPERTIES
+      OUTPUT_NAME libphpdbg
+  )
+endif()
+
 ################################################################################
 # Readline support.
 ################################################################################
@@ -183,6 +210,9 @@ if(PHP_SAPI_PHPDBG_READLINE OR PHP_EXT_READLINE)
     )
 
     target_link_libraries(php_sapi_phpdbg PRIVATE Readline::Readline)
+    if(TARGET php_sapi_phpdbg_shared)
+      target_link_libraries(php_sapi_phpdbg_shared PRIVATE Readline::Readline)
+    endif()
 
     set(HAVE_LIBREADLINE TRUE)
   else()
@@ -195,6 +225,9 @@ if(PHP_SAPI_PHPDBG_READLINE OR PHP_EXT_READLINE)
     )
 
     target_link_libraries(php_sapi_phpdbg PRIVATE Editline::Editline)
+    if(TARGET php_sapi_phpdbg_shared)
+      target_link_libraries(php_sapi_phpdbg_shared PRIVATE Editline::Editline)
+    endif()
 
     set(HAVE_LIBEDIT TRUE)
   endif()
@@ -210,36 +243,6 @@ add_feature_info(
   "enhanced command-line accessibility"
 )
 
-################################################################################
-# The phpdbg shared library.
-################################################################################
-
-# TODO: Should readline support be also enabled like in the executable?
-# TODO: fix this better in the future (building with -fPIC etc).
-if(PHP_SAPI_PHPDBG_SHARED)
-  add_library(php_sapi_phpdbg_shared SHARED)
-  add_library(PHP::sapi::phpdbg_shared ALIAS php_sapi_phpdbg_shared)
-
-  set_target_properties(php_sapi_phpdbg_shared PROPERTIES OUTPUT_NAME phpdbg)
-
-  target_sources(php_sapi_phpdbg_shared PRIVATE ${phpdbgSources})
-
-  target_compile_definitions(
-    php_sapi_phpdbg_shared
-    PRIVATE
-      ZEND_ENABLE_STATIC_TSRMLS_CACHE
-      $<$<PLATFORM_ID:Windows>:YY_NO_UNISTD_H>
-      $<IF:$<BOOL:${PHP_SAPI_PHPDBG_DEBUG}>,PHPDBG_DEBUG=1,PHPDBG_DEBUG=0>
-  )
-
-  target_link_libraries(
-    php_sapi_phpdbg_shared
-    PRIVATE
-      $<BUILD_INTERFACE:PHP::sapi>
-      $<$<PLATFORM_ID:Windows>:ws2_32;user32>
-  )
-endif()
-
 ################################################################################
 # Generate parser and lexer files.
 ################################################################################
@@ -267,6 +270,9 @@ if(HAVE_UFFDIO_WRITEPROTECT_MODE_WP)
     find_package(Threads)
     if(Threads_FOUND)
       target_link_libraries(php_sapi_phpdbg PRIVATE Threads::Threads)
+      if(TARGET php_sapi_phpdbg_shared)
+        target_link_libraries(php_sapi_phpdbg_shared PRIVATE Threads::Threads)
+      endif()
     else()
       message(WARNING "Threads not available.")
     endif()
@@ -313,4 +319,41 @@ php_install(CODE "
   )
 ")
 
+# Configure pkg-config phpdbg.pc metadata file and install shared phpdbg module.
+if(TARGET php_sapi_phpdbg_shared)
+  include(PHP/PkgConfig)
+  php_pkgconfig_generate_pc(
+    phpdbg.pc.in
+    phpdbg.pc
+    TARGET PHP::sapi::phpdbg_shared
+    VARIABLES
+      prefix "$<INSTALL_PREFIX>"
+      exec_prefix "$<INSTALL_PREFIX>"
+      includedir "$<PATH:ABSOLUTE_PATH,NORMALIZE,${CMAKE_INSTALL_INCLUDEDIR},$<INSTALL_PREFIX>>"
+      php_include_prefix "${PHP_INCLUDE_PREFIX}"
+      libdir "$<PATH:ABSOLUTE_PATH,NORMALIZE,${CMAKE_INSTALL_LIBDIR},$<INSTALL_PREFIX>>"
+      PHP_VERSION "${PHP_VERSION}"
+      PHP_VERSION_ID "${PHP_VERSION_ID}"
+      PHP_EXTENSION_DIR "$<PATH:ABSOLUTE_PATH,NORMALIZE,${PHP_EXTENSION_DIR},$<INSTALL_PREFIX>>"
+      # TODO: Fix this for cmake --install ... --prefix
+      PHP_CONFIG_FILE_SCAN_DIR "$<PATH:ABSOLUTE_PATH,NORMALIZE,${PHP_CONFIG_FILE_SCAN_DIR},$<INSTALL_PREFIX>>"
+      PHP_CONFIG_FILE_PATH "$<PATH:ABSOLUTE_PATH,NORMALIZE,${PHP_CONFIG_FILE_PATH},$<INSTALL_PREFIX>>"
+      PHP_DEBUG "$<IF:$<CONFIG:Debug,DebugAssertions>,yes,no>"
+      PHP_THREAD_SAFETY "$<IF:$<BOOL:$<TARGET_PROPERTY:PHP::config,PHP_THREAD_SAFETY>>,yes,no>"
+  )
+
+  install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/phpdbg.pc
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig
+  )
+
+  install(
+    TARGETS php_sapi_phpdbg_shared
+    LIBRARY
+      DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME
+      DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  )
+endif()
+
 configure_file(cmake/config.h.in config.h)