From 949321762b65f2f35829cb1c141482d25092e8ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Janiszewski?= <janisozaur@gmail.com>
Date: Sun, 3 Jun 2018 22:54:01 +0200
Subject: [PATCH] Verify compilability of headers on Travis v2

Using approach described in
https://github.com/OpenRCT2/OpenRCT2/pull/7369#issuecomment-393973857
with updates to ease readability and maintenance.

Submitted as different PR, to keep history of the old approach.
Supersedes #7369.
---
 src/openrct2/CMakeLists.txt | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/openrct2/CMakeLists.txt b/src/openrct2/CMakeLists.txt
index 1d59906fa2..9235d29131 100644
--- a/src/openrct2/CMakeLists.txt
+++ b/src/openrct2/CMakeLists.txt
@@ -59,8 +59,8 @@ if (NOT DISABLE_TTF)
 endif ()
 
 # Sources
-file(GLOB_RECURSE OPENRCT2_CORE_SOURCES "${CMAKE_CURRENT_LIST_DIR}/*.cpp"
-                                        "${CMAKE_CURRENT_LIST_DIR}/*.h"
+file(GLOB_RECURSE OPENRCT2_CORE_SOURCES "${CMAKE_CURRENT_LIST_DIR}/*.cpp")
+file(GLOB_RECURSE OPENRCT2_CORE_HEADERS "${CMAKE_CURRENT_LIST_DIR}/*.h"
                                         "${CMAKE_CURRENT_LIST_DIR}/*.hpp")
 if (APPLE)
     file(GLOB_RECURSE OPENRCT2_CORE_MM_SOURCES "${CMAKE_CURRENT_LIST_DIR}/*.mm")
@@ -179,3 +179,19 @@ if((X86 OR X86_64) AND NOT MSVC)
     set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/drawing/SSE41Drawing.cpp PROPERTIES COMPILE_FLAGS -msse4.1)
     set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/drawing/AVX2Drawing.cpp PROPERTIES COMPILE_FLAGS -mavx2)
 endif()
+
+# Add headers check to verify all headers carry their dependencies.
+# Only valid for Clang for now:
+# - GCC 8 does not support -Wno-pragma-once-outside-header
+# - Other compilers status unknown
+if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+    add_library(${PROJECT}-headers-check ${OPENRCT2_CORE_HEADERS})
+    set_target_properties(${PROJECT}-headers-check PROPERTIES LINKER_LANGUAGE CXX)
+    set_source_files_properties(${OPENRCT2_CORE_HEADERS} PROPERTIES LANGUAGE CXX)
+    add_definitions("-x c++ -Wno-pragma-once-outside-header -Wno-unused-const-variable")
+    get_target_property(LIBOPENRCT2_INCLUDE_DIRS ${PROJECT} INCLUDE_DIRECTORIES)
+    set_target_properties(${PROJECT}-headers-check PROPERTIES INCLUDE_DIRECTORIES ${LIBOPENRCT2_INCLUDE_DIRS})
+else ()
+    # Dummy target to ease invocation
+    add_custom_target(${PROJECT}-headers-check)
+endif ()