From: Joel Rosdahl <joel@rosdahl.net>
Date: Wed, 29 May 2024 18:54:31 +0000 (+0200)
Subject: build: Fix zstd build for older CMake versions
X-Git-Tag: v4.10~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=536a632924f4d6543d802833b60127108abb19d2;p=thirdparty%2Fccache.git

build: Fix zstd build for older CMake versions

With CMake 3.17.5 on CentOS7:

    -- Downloading Zstd from the internet since Zstd>=1.3.4 was not found locally and DEPS=AUTO
    CMake Error at cmake/FindZstd.cmake:60 (set_target_properties):
      set_target_properties Can not find target to add properties to:
      libzstd_static
    Call Stack (most recent call first):
      cmake/Dependencies.cmake:29 (find_package)
      CMakeLists.txt:88 (include)

    CMake Error at cmake/FindZstd.cmake:68 (add_library):
      add_library cannot create ALIAS target "dep_zstd" because target
      "libzstd_static" does not already exist.
    Call Stack (most recent call first):
      cmake/Dependencies.cmake:29 (find_package)
      CMakeLists.txt:88 (include)
---

diff --git a/cmake/FindZstd.cmake b/cmake/FindZstd.cmake
index 5622b2dd..662c1f3e 100644
--- a/cmake/FindZstd.cmake
+++ b/cmake/FindZstd.cmake
@@ -53,7 +53,13 @@ if(_download_zstd)
     SOURCE_SUBDIR build/cmake
     ${_zstd_patch}
   )
-  FetchContent_MakeAvailable(Zstd)
+
+  # When it works: Use FetchContent_MakeAvailable(Zstd) instead
+  FetchContent_GetProperties(zstd)
+  if(NOT zstd_POPULATED)
+    FetchContent_Populate(Zstd)
+    add_subdirectory("${zstd_SOURCE_DIR}/build/cmake" "${zstd_BINARY_DIR}" EXCLUDE_FROM_ALL)
+  endif()
 
   # Workaround until https://github.com/facebook/zstd/pull/3968 is included in a
   # release: