h5fortran_hdf5_nobuild option to disable auto-build

Author: scivision

CMakePresets.json

@@ -23,11 +23,10 @@
     "FETCHCONTENT_TRY_FIND_PACKAGE_MODE": "NEVER"
   }
 },
-{ "name": "no-build", "inherits": "default",
-  "displayName": "Don't build HDF5 and ZLib from source with h5fortran if not found",
+{ "name": "no-build-hdf5", "inherits": "default",
+  "displayName": "Don't build HDF5 and ZLib from source if not found",
   "cacheVariables": {
-    "FETCHCONTENT_TRY_FIND_PACKAGE_MODE": "ALWAYS",
-    "FETCHCONTENT_FULLY_DISCONNECTED": true
+    "h5fortran_hdf5_nobuild": true
   }
 },
 { "name": "debug", "inherits": "default",
@@ -67,6 +66,7 @@
 "buildPresets": [
   { "name": "default", "configurePreset": "default" },
   { "name": "build", "configurePreset": "build", "inherits": "default" },
+  { "name": "no-build-hdf5", "configurePreset": "no-build-hdf5", "inherits": "default" },
   { "name": "shared",  "configurePreset": "shared", "inherits": "default" },
   {
     "name": "explain",
@@ -137,6 +137,14 @@
       { "type": "build", "name": "build" }
     ]
   },
+  {
+    "name": "no-build-hdf5",
+    "displayName": "Don't build HDF5 and ZLib from source if not found",
+    "steps": [
+      { "type": "configure", "name": "no-build-hdf5" },
+      { "type": "build", "name": "no-build-hdf5" }
+    ]
+  },
   {
     "name": "debug",
     "displayName": "Build and Test in Debug mode",

README.md

@@ -36,7 +36,7 @@ h5fortran is designed for easy use using static or shared linking from your proj
 If using CMake, h5fortran will automatically build the HDF5 library (and Zlib if HDF5 2.x) from source if a compiler-compatible HDF5 is not found on the system.
 HDF5 auto-build options include:
 
-* To disable the auto-build of HDF5 use `cmake --preset no-build`
+* To disable the auto-build of HDF5 use `cmake --preset no-build-hdf5`
 * To always build HDF5 from source, set `cmake --preset build`
 * To use CMake factory FindHDF5 instead of our custom FindHDF5.cmake use `cmake -Dh5fortran_find_hdf5_factory=yes`
 * To disable the use of HDF5 compiler wrappers in finding HDF5 use `cmake -DHDF5_NO_FIND_WRAPPER=yes`

cmake/hdf5.cmake

@@ -110,11 +110,12 @@ endif()
 
 if(NOT TARGET HDF5::HDF5)
 
-FetchContent_Declare(HDF5 URL ${hdf5_url} FIND_PACKAGE_ARGS COMPONENTS HL Fortran C)
-# "C" as well so that link tests work and corner cases OK
-
-FetchContent_MakeAvailable(HDF5)
-
+if(h5fortran_hdf5_nobuild)
+  find_package(HDF5 REQUIRED COMPONENTS HL Fortran C)
+else()
+  FetchContent_Declare(HDF5 URL ${hdf5_url} FIND_PACKAGE_ARGS COMPONENTS HL Fortran C)
+  # "C" as well so that link tests work and corner cases OK
+  FetchContent_MakeAvailable(HDF5)
 endif()
 
 

options.cmake

@@ -5,6 +5,7 @@ include(GNUInstallDirs)
 option(BUILD_SHARED_LIBS "Build shared libraries" OFF)
 
 option(h5fortran_hdf5_zlib "use Zlib when building HDF5" ON)
+option(h5fortran_hdf5_nobuild "only find HDF5, do not build HDF5" OFF)
 
 option(h5fortran_warning_as_error "treat warnings as errors" OFF)