Add CMakeLists.txt for coreHTTP library (#197)

* Add CMakeLists.txt for coreHTTP library

* Fix formatting.

* Update core_http target to link to transport interface.

* Fix INTERFACE library link

---------

Co-authored-by: czjaso <czjaso@amazon.com>

Author: jasonpcarroll

CMakeLists.txt

@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.15)
+
+project(coreHTTP LANGUAGES C)
+
+# ------------------------------------------------------------------------------
+# Includes
+# ------------------------------------------------------------------------------
+
+include(${CMAKE_CURRENT_LIST_DIR}/httpFilePaths.cmake)
+
+# ------------------------------------------------------------------------------
+# Library targets
+# ------------------------------------------------------------------------------
+
+add_library(core_http INTERFACE)
+
+target_sources(core_http INTERFACE ${HTTP_SOURCES})
+
+target_include_directories(core_http
+                           INTERFACE ${HTTP_INCLUDE_NO_INTERFACE_PUBLIC_DIRS})
+
+# Separate transport interface library to prevent conflicts with coreMQTT
+if(NOT TARGET coremqtt_corehttp_transport_interface)
+  add_library(coremqtt_corehttp_transport_interface INTERFACE)
+
+  target_include_directories(coremqtt_corehttp_transport_interface
+                             INTERFACE ${HTTP_TRANSPORT_INTERFACE_INCLUDE_DIRS})
+endif()
+
+target_link_libraries(core_http INTERFACE coremqtt_corehttp_transport_interface)

httpFilePaths.cmake

@@ -12,8 +12,16 @@ set( HTTP_SOURCES
      ${CMAKE_CURRENT_LIST_DIR}/source/dependency/3rdparty/llhttp/src/llhttp.c
      ${CMAKE_CURRENT_LIST_DIR}/source/dependency/3rdparty/llhttp/src/http.c )
 
-# HTTP library public include directories.
-set( HTTP_INCLUDE_PUBLIC_DIRS
+# HTTP library public include directories without transport interface.
+set( HTTP_INCLUDE_NO_INTERFACE_PUBLIC_DIRS
      ${CMAKE_CURRENT_LIST_DIR}/source/include
-     ${CMAKE_CURRENT_LIST_DIR}/source/interface
      ${CMAKE_CURRENT_LIST_DIR}/source/dependency/3rdparty/llhttp/include )
+
+# Transport interface include directory.
+set( HTTP_TRANSPORT_INTERFACE_INCLUDE_DIRS
+     ${CMAKE_CURRENT_LIST_DIR}/source/interface )
+
+# HTTP library public include directories.
+set( HTTP_INCLUDE_PUBLIC_DIRS
+     ${HTTP_INCLUDE_NO_INTERFACE_PUBLIC_DIRS}
+     ${HTTP_TRANSPORT_INTERFACE_INCLUDE_DIRS} )