From 16c1dca933aa13c6a426b921b4a4135816d94b9c Mon Sep 17 00:00:00 2001
From: Urs Fleisch <ufleisch@users.sourceforge.net>
Date: Sun, 28 Jan 2024 19:06:40 +0100
Subject: [PATCH] Detect utf8cpp by header if cmake config is not found (#1217)

---
 CMakeLists.txt | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 589920bc1..0e9df4a87 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -149,18 +149,33 @@ if(TRACE_IN_RELEASE)
 endif()
 
 find_package(utf8cpp QUIET)
-if(NOT utf8cpp_FOUND)
-  if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/utfcpp/CMakeLists.txt)
-    add_subdirectory("3rdparty/utfcpp")
-    message(STATUS "Using utfcpp from ${utf8cpp_SOURCE_DIR}")
+if(utf8cpp_FOUND)
+  message(STATUS "Using utfcpp ${utf8cpp_VERSION} from ${utf8cpp_CONFIG}")
+else()
+  find_path(utf8cpp_INCLUDE_DIR NAMES utf8.h PATH_SUFFIXES utf8cpp
+            DOC "utf8cpp include directory")
+  mark_as_advanced(utf8cpp_INCLUDE_DIR)
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(utf8cpp REQUIRED_VARS utf8cpp_INCLUDE_DIR)
+  if(utf8cpp_FOUND)
+    set(utf8cpp_INCLUDE_DIRS "${utf8cpp_INCLUDE_DIR}")
+    if(NOT TARGET utf8::cpp)
+      add_library(utf8::cpp INTERFACE IMPORTED)
+      set_target_properties(utf8::cpp PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES "${utf8cpp_INCLUDE_DIR}")
+    endif()
+    message(STATUS "Using utfcpp from ${utf8cpp_INCLUDE_DIR}")
   else()
-    message(FATAL_ERROR
-      "utfcpp not found. Either install package (probably utfcpp, utf8cpp, or libutfcpp-dev) "
-      "or fetch the git submodule using\n"
-      "git submodule update --init")
+    if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/utfcpp/CMakeLists.txt)
+      add_subdirectory("3rdparty/utfcpp")
+      message(STATUS "Using utfcpp from ${utf8cpp_SOURCE_DIR}")
+    else()
+      message(FATAL_ERROR
+        "utfcpp not found. Either install package (probably utfcpp, utf8cpp, or libutfcpp-dev) "
+        "or fetch the git submodule using\n"
+        "git submodule update --init")
+    endif()
   endif()
-else()
-  message(STATUS "Using utfcpp ${utf8cpp_VERSION} from ${utf8cpp_CONFIG}")
 endif()
 
 add_subdirectory(taglib)