add -Dzlib_legacy:BOOL option for Zlib 1.x fallback (default 2.x)

Author: scivision

README.md

@@ -98,6 +98,13 @@ set FC=ifort
 This is necessary to workaround techniques used by HDF5 CMake files that don't pickup the CMake `set(ENV{CC})`.
 Otherwise, HDF5 build failures may result due to defaulting to icl-clang.
 
+By default we use Zlib 2.x a.k.a. zlib-ng.
+If you have a problem with Zlib-ng on your system, try the unmaintained Zlib 1.x by:
+
+```sh
+cmake -B build -Dzlib_legacy=on
+```
+
 ## Usage
 
 The simplest [example](./Examples/) h5fortran usage is like:

VERSION

@@ -1 +1 @@
-3.7.1
+3.7.2

cmake/build_zlib.cmake

@@ -3,7 +3,11 @@
 include(ExternalProject)
 
 if(WIN32)
-  set(ZLIB_name ${CMAKE_STATIC_LIBRARY_PREFIX}zlib${CMAKE_STATIC_LIBRARY_SUFFIX})
+  if(zlib_legacy)
+    set(ZLIB_name ${CMAKE_STATIC_LIBRARY_PREFIX}zlibstatic${CMAKE_STATIC_LIBRARY_SUFFIX})
+  else()
+    set(ZLIB_name ${CMAKE_STATIC_LIBRARY_PREFIX}zlib${CMAKE_STATIC_LIBRARY_SUFFIX})
+  endif()
 else()
   set(ZLIB_name ${CMAKE_STATIC_LIBRARY_PREFIX}z${CMAKE_STATIC_LIBRARY_SUFFIX})
 endif()
@@ -24,7 +28,7 @@ ExternalProject_Add(ZLIB
 URL ${zlib_url}
 URL_HASH SHA256=${zlib_sha256}
 CONFIGURE_HANDLED_BY_BUILD ON
-INACTIVITY_TIMEOUT 30
+INACTIVITY_TIMEOUT 15
 CMAKE_ARGS -DZLIB_COMPAT:BOOL=on -DZLIB_ENABLE_TESTS:BOOL=off -DBUILD_SHARED_LIBS:BOOL=off -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX:PATH=${ZLIB_ROOT}
 BUILD_BYPRODUCTS ${ZLIB_LIBRARY}
 )

cmake/libraries.cmake

@@ -9,8 +9,13 @@ else()
   # CMake >= 3.19
   file(READ ${CMAKE_CURRENT_LIST_DIR}/libraries.json _libj)
 
-  string(JSON zlib_url GET ${_libj} zlib url)
-  string(JSON zlib_sha256 GET ${_libj} zlib sha256)
+  if(zlib_legacy)
+    string(JSON zlib_url GET ${_libj} zlib1 url)
+    string(JSON zlib_sha256 GET ${_libj} zlib1 sha256)
+  else()
+    string(JSON zlib_url GET ${_libj} zlib2 url)
+    string(JSON zlib_sha256 GET ${_libj} zlib2 sha256)
+  endif()
 
   string(JSON hdf5_url GET ${_libj} hdf5 url)
   string(JSON hdf5_sha256 GET ${_libj} hdf5 sha256)

cmake/libraries.json

@@ -3,7 +3,7 @@
     "url": "https://zlib.net/zlib1211.zip",
     "sha256": "d7510a8ee1918b7d0cad197a089c0a2cd4d6df05fee22389f67f115e738b178d"
 },
-"zlib": {
+"zlib2": {
     "url" : "https://github.com/zlib-ng/zlib-ng/archive/refs/tags/2.0.2.zip",
     "sha256": "58a86813746ac1e2354244b1e01f22d8b4814c69e7a8fca14c657d13f67bb5bc"
 },

cmake/options.cmake

@@ -6,6 +6,11 @@ option(shaky "run shaky tests that may segfault since designed to fail" off)
 option(matlab "check HDF5 file writes with Matlab" off)
 option(concepts "conceptual testing, for devs only" off)
 
+option(zlib_legacy "use unmaintained ZLIB 1.x")
+if(zlib_legacy AND CMAKE_VERSION VERSION_LESS 3.19)
+  message(FATAL_ERROR "Zlib 1.x requires CMake >= 3.19")
+endif()
+
 set(CMAKE_EXPORT_COMPILE_COMMANDS true)
 
 set(CMAKE_TLS_VERIFY true)