From ecc41d64cf87ebc5affe7edcb31fa2e25fea0249 Mon Sep 17 00:00:00 2001
From: Moody <76251897+moodyhunter@users.noreply.github.com>
Date: Wed, 30 Jun 2021 18:48:25 +0800
Subject: [PATCH] + added CMake package configuration files

Previously, uvw provides only a pkg-config .pc file, although a uvw.cmake presents,
it's not properly installed and placed in to a correct cmake `find_package` search path.

This leads to many problems, where in this commit, a `uvw::uvw` ALIAS target is created for uvw static library,

- if `BUILD_UVW_LIBS` is set, FETCH_LIBUV must be set as well (otherwise it'll not build, it's the current behavior).
- if `BUILD_UVW_LIBS` is NOT set:
    - when `FETCH_LIBUV` is set, it's guaranteed that uv::uv-static target exists, so a genex is removed.
    - when `FETCH_LIBUV` is NOT set, it's the caller's responsibility to make sure libuv can be properly linked

This commit also fixes CMake package config files for uvw, they are now installed as ${LIBDIR}/cmake/uvw/uvwConfig.cmake
with target files for appropriate configuration (e.g. debug, release, etc...).

Callers can now use `find_package(uvw)` and link with the `uvw::uvw` target to use uvw in their projects directly using CMake.
---
 CMakeLists.txt     | 12 ++++++++++++
 src/CMakeLists.txt | 34 +++++++++++++---------------------
 2 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b82fb73..b67fef43 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -155,6 +155,18 @@ install(
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
 )
 
+#
+# Install targets
+#
+
+install(EXPORT uvwConfig NAMESPACE uvw:: DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/uvw)
+install(TARGETS uvw EXPORT uvwConfig ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+if(FETCH_LIBUV AND BUILD_UVW_LIBS)
+    # libuv is only fetched when both above conditions are true
+    install(TARGETS uv_a EXPORT uvwConfig ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    install(TARGETS uv EXPORT uvwConfig LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+endif(FETCH_LIBUV AND BUILD_UVW_LIBS)
+
 #
 # Pkg-Config
 #
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 414f6c3c..3e949e47 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -57,34 +57,26 @@ function(add_uvw_library LIB_NAME)
     endif()
 endfunction()
 
-# 
+#
 # Build and install libraries
 #
 
 if (BUILD_UVW_SHARED_LIB)
-    add_library(uvw-shared SHARED)
-    add_library(uvw::uvw-shared ALIAS uvw-shared)
-    target_link_libraries(uvw-shared PUBLIC $<$<TARGET_EXISTS:uv::uv-shared>:uv::uv-shared>)
-    set_target_properties(uvw-shared PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD 1)
-
-    add_uvw_library(uvw-shared)
-
-    install(TARGETS uvw-shared EXPORT uvw ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR})
-
+    add_library(uvw SHARED)
+    add_library(uvw::uvw-shared ALIAS uvw)
+    # If libuv is not fetched by ourselves, it's the caller's responsibility to make sure of the linkage.
     if(FETCH_LIBUV)
-        install(TARGETS uv_a EXPORT uvw ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+        target_link_libraries(uvw PUBLIC uv::uv-shared)
     endif()
 else()
-    add_library(uvw-static STATIC)
-    add_library(uvw::uvw-static ALIAS uvw-static)
-    target_link_libraries(uvw-static PUBLIC $<$<TARGET_EXISTS:uv::uv-static>:uv::uv-static> $<$<NOT:$<TARGET_EXISTS:uv::uv-static>>:uv_a dl>)
-    set_target_properties(uvw-static PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD 1)
-
-    add_uvw_library(uvw-static)
-
-    install(TARGETS uvw-static EXPORT uvw ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
-
+    add_library(uvw STATIC)
+    add_library(uvw::uvw-static ALIAS uvw)
+    # If libuv is not fetched by ourselves, it's the caller's responsibility to make sure of the linkage.
     if(FETCH_LIBUV)
-        install(TARGETS uv EXPORT uvw LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+        target_link_libraries(uvw PUBLIC uv::uv-static)
     endif()
 endif()
+
+add_library(uvw::uvw ALIAS uvw)
+set_target_properties(uvw PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD 1)
+add_uvw_library(uvw)