From 9c4907da9c032e0787a59ed19ffb90c9fb313f39 Mon Sep 17 00:00:00 2001
From: Ryan Burns <rtburns@protonmail.com>
Date: Fri, 8 Oct 2021 10:50:29 -0700
Subject: [PATCH] Support configurable include install dir

This is useful for split-output packaging, where the
development headers are separate from the runtime libraries.
---
 CMakeLists.txt | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 14964ecf..e9973f44 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,8 +16,13 @@ endif()
 
 if (UNIX AND NOT APPLE)
     include(GNUInstallDirs)
-elseif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
-    set(CMAKE_INSTALL_LIBDIR "lib")
+else()
+    if(NOT DEFINED CMAKE_INSTALL_INCLUDEDIR)
+        set(CMAKE_INSTALL_INCLUDEDIR "include")
+    endif()
+    if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+        set(CMAKE_INSTALL_LIBDIR "lib")
+    endif()
 endif()
 
 # This is required in order to append /lib/cmake to each element in CMAKE_PREFIX_PATH
@@ -86,18 +91,18 @@ set_target_properties(${PROJECT_NAME} PROPERTIES VERSION 1.0.0)
 
 target_include_directories(${PROJECT_NAME} PUBLIC
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-        $<INSTALL_INTERFACE:include>)
+        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
 
 aws_use_package(aws-c-http)
 
 target_link_libraries(${PROJECT_NAME} PUBLIC ${DEP_AWS_LIBS})
 aws_prepare_shared_lib_exports(${PROJECT_NAME})
 
-install(FILES ${AWS_MQTT_HEADERS} DESTINATION "include/aws/mqtt" COMPONENT Development)
-install(FILES ${AWS_MQTT5_HEADERS} DESTINATION "include/aws/mqtt/v5" COMPONENT Development)
-install(FILES ${AWS_MQTT_RR_HEADERS} DESTINATION "include/aws/mqtt/request-response" COMPONENT Development)
-install(FILES ${AWS_MQTT_TESTING_HEADERS} DESTINATION "include/aws/testing/mqtt" COMPONENT Development)
-install(FILES ${AWS_MQTT_PRIV_EXPOSED_HEADERS} DESTINATION "include/aws/mqtt/private" COMPONENT Development)
+install(FILES ${AWS_MQTT_HEADERS} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/aws/mqtt" COMPONENT Development)
+install(FILES ${AWS_MQTT5_HEADERS} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/aws/mqtt/v5" COMPONENT Development)
+install(FILES ${AWS_MQTT_RR_HEADERS} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/aws/mqtt/request-response" COMPONENT Development)
+install(FILES ${AWS_MQTT_TESTING_HEADERS} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/aws/testing/mqtt" COMPONENT Development)
+install(FILES ${AWS_MQTT_PRIV_EXPOSED_HEADERS} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/aws/mqtt/private" COMPONENT Development)
 
 if (BUILD_SHARED_LIBS)
     set (TARGET_DIR "shared")