Use ExternalProject module

Author: petk

cmake/cmake/modules/PHP/Package/ZLIB.cmake

@@ -0,0 +1,99 @@
+#[=============================================================================[
+# PHP/Package/Zlib
+
+Finds or downloads the zlib library:
+
+```cmake
+include(PHP/Package/Zlib)
+```
+
+This module is a wrapper for finding the `ZLIB` library. It first tries to find
+the `ZLIB` library on the system. If not successful it tries to download it from
+the upstream source with `ExternalProject` module and builds it together with
+the PHP build.
+
+See: https://cmake.org/cmake/help/latest/module/FindZLIB.html
+
+## Examples
+
+```cmake
+include(PHP/Package/ZLIB)
+target_link_libraries(php_ext_foo PRIVATE ZLIB::ZLIB)
+#]=============================================================================]
+
+include(FeatureSummary)
+include(ExternalProject)
+
+set_package_properties(
+  ZLIB
+  PROPERTIES
+    URL "https://zlib.net/"
+    DESCRIPTION "Compression library"
+)
+
+# Minimum required version for the zlib dependency.
+set(PHP_ZLIB_MIN_VERSION 1.2.0.4)
+#set(PHP_ZLIB_MIN_VERSION 1.3.1)
+
+# Download version when system dependency is not found.
+set(PHP_ZLIB_DOWNLOAD_VERSION 1.3.1)
+
+if(TARGET ZLIB::ZLIB)
+  set(ZLIB_FOUND TRUE)
+  return()
+endif()
+
+find_package(ZLIB ${PHP_ZLIB_MIN_VERSION})
+
+if(NOT ZLIB_FOUND)
+  message(
+    STATUS
+    "ZLIB ${PHP_ZLIB_DOWNLOAD_VERSION} will be downloaded at build phase"
+  )
+
+  set(zlib_options "-DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>")
+
+  if(PHP_ZLIB_DOWNLOAD_VERSION VERSION_LESS_EQUAL 1.3.1)
+    list(APPEND zlib_options -DZLIB_BUILD_EXAMPLES=OFF)
+  endif()
+
+  if(PHP_ZLIB_DOWNLOAD_VERSION VERSION_GREATER 1.3.1)
+    list(APPEND zlib_options -DZLIB_BUILD_TESTING=OFF)
+  endif()
+
+  ExternalProject_Add(
+    ZLIB
+    STEP_TARGETS build install
+    URL
+      https://github.com/madler/zlib/releases/download/v${PHP_ZLIB_DOWNLOAD_VERSION}/zlib-${PHP_ZLIB_DOWNLOAD_VERSION}.tar.gz
+    CMAKE_ARGS ${zlib_options}
+    INSTALL_DIR ${CMAKE_CURRENT_BINARY_DIR}/zlib-installation
+    INSTALL_BYPRODUCTS <INSTALL_DIR>/lib/libz.so
+  )
+
+  # Move dependency to PACKAGES_FOUND.
+  block()
+    get_cmake_property(packagesNotFound PACKAGES_NOT_FOUND)
+    list(REMOVE_ITEM packagesNotFound ZLIB)
+    set_property(GLOBAL PROPERTY PACKAGES_NOT_FOUND packagesNotFound)
+    get_cmake_property(packagesFound PACKAGES_FOUND)
+    set_property(GLOBAL APPEND PROPERTY PACKAGES_FOUND ZLIB)
+  endblock()
+
+  ExternalProject_Get_Property(ZLIB INSTALL_DIR)
+
+  # Bypass issue with non-existing include directory for the imported target.
+  file(MAKE_DIRECTORY ${INSTALL_DIR}/include)
+
+  add_library(ZLIB::ZLIB STATIC IMPORTED GLOBAL)
+  set_target_properties(
+    ZLIB::ZLIB
+    PROPERTIES
+      IMPORTED_LOCATION "${INSTALL_DIR}/lib/libz.${CMAKE_STATIC_LIBRARY_SUFFIX}"
+      INTERFACE_INCLUDE_DIRECTORIES "${INSTALL_DIR}/include"
+  )
+  add_dependencies(ZLIB::ZLIB ZLIB-install)
+
+  # Mark package as found.
+  set(ZLIB_FOUND TRUE)
+endif()

cmake/cmake/modules/Packages/LibXml2.cmake

@@ -54,7 +54,7 @@ FetchContent_Declare(
 find_package(LibXml2 ${PHP_LIBXML2_MIN_VERSION})
 
 if(NOT LibXml2_FOUND)
-  include(Packages/ZLIB)
+  include(PHP/Package/ZLIB)
 
   set(FETCHCONTENT_QUIET NO)
   set(LIBXML2_WITH_PYTHON OFF)

cmake/cmake/modules/Packages/ZLIB.cmake

@@ -316,7 +316,7 @@ if(NOT PHP_EXT_GD_EXTERNAL)
     )
   endif()
 
-  include(Packages/ZLIB)
+  include(PHP/Package/ZLIB)
   set_package_properties(
     ZLIB
     PROPERTIES

cmake/ext/gd/CMakeLists.txt

@@ -170,7 +170,7 @@ target_link_libraries(
 )
 
 if(PHP_EXT_MYSQLND_COMPRESSION)
-  include(Packages/ZLIB)
+  include(PHP/Package/ZLIB)
   set_package_properties(
     ZLIB
     PROPERTIES

cmake/ext/mysqlnd/CMakeLists.txt

@@ -22,6 +22,9 @@ Use external crypt library, such as libcrypt or libxcrypt, instead of the
 bundled PHP crypt.
 #]=============================================================================]
 
+# TODO: ext/standard/image.c depends on zlib extension and its macros but it
+# should only depend on zlib library.
+
 project(
   PhpExtensionStandard
   LANGUAGES C

cmake/ext/standard/CMakeLists.txt

@@ -77,16 +77,25 @@ endif()
 
 target_compile_definitions(php_ext_zlib PRIVATE ZEND_ENABLE_STATIC_TSRMLS_CACHE)
 
-include(Packages/ZLIB)
+include(PHP/Package/ZLIB)
 set_package_properties(
   ZLIB
   PROPERTIES
     TYPE REQUIRED
     PURPOSE "Necessary to enable the zlib extension."
 )
 
+# Link publicly for internal_functions files and ext/standard/image.c.
 target_link_libraries(php_ext_zlib PUBLIC ZLIB::ZLIB)
 
+# TODO: zlib.h must exist when building php_main* targets.
+add_dependencies(
+  php_ext_zlib
+  php_main
+  php_main_internal_functions
+  php_main_internal_functions_cli
+)
+
 set(HAVE_ZLIB TRUE)
 
 configure_file(cmake/config.h.in config.h)