From 06600440feee6b879c6283290ae9126318772ebc Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sat, 26 Jan 2019 18:41:56 +0100
Subject: [PATCH 1/6] Enable LTO/IPO on Clang and GCC

---
 CMakeLists.txt                  | 168 ++++++++++++++++++--------------
 src/openrct2-cli/CMakeLists.txt |   6 +-
 src/openrct2-ui/CMakeLists.txt  |   6 +-
 src/openrct2/CMakeLists.txt     |   2 +-
 4 files changed, 108 insertions(+), 74 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06329c0699..6ca9377612 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,11 +1,19 @@
 # CMAKE project for openrct2
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif()
 
 project(openrct2 CXX)
 
+include(CheckIPOSupported)
+check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
+if(IPO_SUPPORTED)
+    message(INFO "IPO supported")
+else()
+    message(WARNING "IPO not supported: ${IPO_LOG}")
+endif()
+
 if (NOT MSVC)
     include(FindPkgConfig)
 endif ()
@@ -80,76 +88,6 @@ execute_process(
     ERROR_QUIET
 )
 
-function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
-    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
-    if (${_CACHE_VAR})
-        set(${_CXXFLAGS} "${${_CXXFLAGS}} ${_FLAG}" PARENT_SCOPE)
-    else ()
-        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
-    endif ()
-endfunction ()
-
-if (MSVC)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /utf-8 /permissive- /Zc:externConstexpr /WX")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4244") # C4244: 'conversion_type': conversion from 'type1' to 'type2', possible loss of data
-
-    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
-    add_definitions(-D_SCL_SECURE_NO_WARNINGS)
-    add_definitions(-D__SSE4_1__)
-    add_definitions(-D__AVX2__)
-else ()
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NULL_DEREFERENCE -Wnull-dereference)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_TYPES -Wsuggest-final-types)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_METHODS -Wsuggest-final-methods)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_OVERRIDE -Wsuggest-override)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_COND -Wduplicated-cond)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NON_VIRTUAL_DTOR -Wnon-virtual-dtor)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_VARIABLE_DECLARATIONS -Wmissing-variable-declarations)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_BRANCHES -Wduplicated-branches)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RESTRICT -Wrestrict)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_FIELD_INITIALIZERS -Wmissing-field-initializers)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_UNREACHABLE_CODE_BREAK -Wunreachable-code-break)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_LOGICAL_OP -Wlogical-op)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RANGE_LOOP_ANALYSIS -Wrange-loop-analysis)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_TAUTOLOGICAL_ZERO_COMPARE -Wtautological-unsigned-zero-compare)
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WNO_CLOBBERED -Wno-clobbered)
-    # Disabled due to problems compiling OpenSSL on macOS.
-    # ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DOCUMENTATION -Wdocumentation)
-
-    # Items below are not supported by ICC
-    if (NOT MINGW)
-        # Do not enable for MinGW, as its headers contain redundant declarations of builtin functions
-        ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_REDUNDANT_DECLS -Wredundant-decls)
-    endif ()
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_IGNORED_QUALIFIERS -Wignored-qualifiers)
-
-    # -Wstrict-overflow is only active when -fstrict-overflow is enabled, but -fstrict-overflow
-    # is enabled on -O2, -O3, -Os. This should help catch bugs locally before they reach Travis
-    # As of 2a435bf -Wstrict-overflow=1 passes, but higher values do not.
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-overflow")
-    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_STRICT_OVERFLOW -Wstrict-overflow=1)
-
-    # Compiler flags
-    set(DEBUG_LEVEL 0 CACHE STRING "Select debug level for compilation. Use value in range 0–3.")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-aliasing -Werror -Wundef -Wmissing-declarations -Winit-self -Wall -Wextra -Wshadow")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-pragmas -Wno-missing-braces -Wno-comment -Wnonnull -Wno-unused-parameter")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDEBUG=${DEBUG_LEVEL}")
-
-    if(APPLE)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=objc-method-access")
-    endif()
-
-    # On mingw all code is already PIC, this will avoid compiler error on redefining this option
-    if (NOT MINGW)
-        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-    endif ()
-
-    if (APPLE AND NOT USE_MMAP)
-        set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
-    else ()
-        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
-    endif ()
-endif ()
 
 # Defines
 if (USE_MMAP)
@@ -227,6 +165,94 @@ if (WITH_TESTS)
     include("${ROOT_DIR}/test/tests/CMakeLists.txt" NO_POLICY_SCOPE)
 endif ()
 
+# Check if a flag exists and add it to the compiler (so, not the linker) options
+function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
+    if (${_CACHE_VAR})
+        if(TARGET ${PROJECT})
+            target_compile_options(${PROJECT} PRIVATE ${_FLAG})
+        endif()
+        if(TARGET ${PROJECT}-cli)
+            target_compile_options(${PROJECT}-cli PRIVATE ${_FLAG})
+        endif()
+    else ()
+        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
+    endif ()
+endfunction ()
+
+# Check if a flag exists and add it to the compiler and the linker options
+function (ADD_CHECK_CXX_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
+    CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
+    if (${_CACHE_VAR})
+        set(${_CXXFLAGS} "${${_CXXFLAGS}} ${_FLAG}" PARENT_SCOPE)
+    else ()
+        message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
+    endif ()
+endfunction ()
+
+if (MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /utf-8 /permissive- /Zc:externConstexpr /WX")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4244") # C4244: 'conversion_type': conversion from 'type1' to 'type2', possible loss of data
+
+    add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+    add_definitions(-D_SCL_SECURE_NO_WARNINGS)
+    add_definitions(-D__SSE4_1__)
+    add_definitions(-D__AVX2__)
+else ()
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NULL_DEREFERENCE -Wnull-dereference)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_TYPES -Wsuggest-final-types)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_FINAL_METHODS -Wsuggest-final-methods)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_SUGGEST_OVERRIDE -Wsuggest-override)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_COND -Wduplicated-cond)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_NON_VIRTUAL_DTOR -Wnon-virtual-dtor)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_VARIABLE_DECLARATIONS -Wmissing-variable-declarations)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DUPLICATED_BRANCHES -Wduplicated-branches)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RESTRICT -Wrestrict)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_MISSING_FIELD_INITIALIZERS -Wmissing-field-initializers)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_UNREACHABLE_CODE_BREAK -Wunreachable-code-break)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_LOGICAL_OP -Wlogical-op)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_RANGE_LOOP_ANALYSIS -Wrange-loop-analysis)
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_TAUTOLOGICAL_ZERO_COMPARE -Wtautological-unsigned-zero-compare)
+    ADD_CHECK_CXX_FLAG(CMAKE_CXX_FLAGS CXX_WNO_CLOBBERED -Wno-clobbered)
+    # Disabled due to problems compiling OpenSSL on macOS.
+    # ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_DOCUMENTATION -Wdocumentation)
+
+    # Items below are not supported by ICC
+    if (NOT MINGW)
+        # Do not enable for MinGW, as its headers contain redundant declarations of builtin functions
+        ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_REDUNDANT_DECLS -Wredundant-decls)
+    endif ()
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_IGNORED_QUALIFIERS -Wignored-qualifiers)
+
+    # -Wstrict-overflow is only active when -fstrict-overflow is enabled, but -fstrict-overflow
+    # is enabled on -O2, -O3, -Os. This should help catch bugs locally before they reach Travis
+    # As of 2a435bf -Wstrict-overflow=1 passes, but higher values do not.
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-overflow")
+    ADD_CHECK_CXX_COMPILER_FLAG(CMAKE_CXX_FLAGS CXX_WARN_STRICT_OVERFLOW -Wstrict-overflow=1)
+
+    # Compiler flags
+    set(DEBUG_LEVEL 0 CACHE STRING "Select debug level for compilation. Use value in range 0–3.")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fstrict-aliasing -Werror -Wundef -Wmissing-declarations -Winit-self -Wall -Wextra -Wshadow")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-pragmas -Wno-missing-braces -Wno-comment -Wnonnull -Wno-unused-parameter")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDEBUG=${DEBUG_LEVEL}")
+
+    if(APPLE)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=objc-method-access")
+    endif()
+
+    # On mingw all code is already PIC, this will avoid compiler error on redefining this option
+    if (NOT MINGW)
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+
+    if (APPLE AND NOT USE_MMAP)
+        set(CMAKE_POSITION_INDEPENDENT_CODE OFF)
+    else ()
+        set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif ()
+endif ()
+
+
 # Install
 # Don't recurse, grab all *.txt and *.md files
 file(GLOB DOC_FILES "${ROOT_DIR}/distribution/*.txt")
diff --git a/src/openrct2-cli/CMakeLists.txt b/src/openrct2-cli/CMakeLists.txt
index 0f6e093162..441324fa44 100644
--- a/src/openrct2-cli/CMakeLists.txt
+++ b/src/openrct2-cli/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for openrct2-cli (CLI-only build of OpenRCT2)
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -15,6 +15,10 @@ set (PROJECT openrct2-cli)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_CLI_SOURCES})
 
+if(IPO_SUPPORTED)
+    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+endif()
+
 target_link_libraries(${PROJECT} "libopenrct2")
 
 # Needed for interactive console
diff --git a/src/openrct2-ui/CMakeLists.txt b/src/openrct2-ui/CMakeLists.txt
index 40e120d4aa..031b46f8c8 100644
--- a/src/openrct2-ui/CMakeLists.txt
+++ b/src/openrct2-ui/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for openrct2-ui (UI build of OpenRCT2)
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()
@@ -50,6 +50,10 @@ set (PROJECT openrct2)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_UI_SOURCES} ${OPENRCT2_UI_MM_SOURCES})
 
+if(IPO_SUPPORTED)
+    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+endif()
+
 target_link_libraries(${PROJECT} "libopenrct2"
                                  ${SDL2_LDFLAGS}
                                  ${SPEEX_LDFLAGS})
diff --git a/src/openrct2/CMakeLists.txt b/src/openrct2/CMakeLists.txt
index bc54c296c1..0471db4717 100644
--- a/src/openrct2/CMakeLists.txt
+++ b/src/openrct2/CMakeLists.txt
@@ -1,5 +1,5 @@
 # CMAKE project for libopenrct2 (core OpenRCT2 component)
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.9)
 if (CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "Building in-source is not supported! Create a build dir and remove ${CMAKE_SOURCE_DIR}/CMakeCache.txt")
 endif ()

From 87d9932792130c2485145fa209318b89f6572d0b Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sun, 27 Jan 2019 12:56:36 +0100
Subject: [PATCH 2/6] Conditionally enable IPO

Put corresponding functionality in `cmake/ipo.cmake`. This directory
allows for future further separation of build concerns.
---
 CMakeLists.txt                  | 12 ++++--------
 cmake/ipo.cmake                 | 24 ++++++++++++++++++++++++
 src/openrct2-cli/CMakeLists.txt |  5 +----
 src/openrct2-ui/CMakeLists.txt  |  5 +----
 4 files changed, 30 insertions(+), 16 deletions(-)
 create mode 100644 cmake/ipo.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6ca9377612..6850784e8d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,14 +6,6 @@ endif()
 
 project(openrct2 CXX)
 
-include(CheckIPOSupported)
-check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
-if(IPO_SUPPORTED)
-    message(INFO "IPO supported")
-else()
-    message(WARNING "IPO not supported: ${IPO_LOG}")
-endif()
-
 if (NOT MSVC)
     include(FindPkgConfig)
 endif ()
@@ -60,6 +52,10 @@ if (PORTABLE OR WIN32)
     set(CMAKE_INSTALL_RPATH "$ORIGIN")
 endif ()
 
+include(cmake/ipo.cmake)
+list(APPEND IPO_ENABLED_BUILDS Release RelWithDebInfo MinSizeRel)
+ipo_enable("${IPO_ENABLED_BUILDS}")
+
 # Describe current version in terms of closest tag
 execute_process(
     COMMAND git describe HEAD
diff --git a/cmake/ipo.cmake b/cmake/ipo.cmake
new file mode 100644
index 0000000000..5df2e9ef06
--- /dev/null
+++ b/cmake/ipo.cmake
@@ -0,0 +1,24 @@
+# Helpers for inter-procedural optimizations (IPO)
+
+# Enabled IPO for a LIST of CMake build types.
+# Provides IPO_BUILD_ENABLED to the parent scope.
+function(ipo_enable IPO_ENABLED_BUILDS)
+    include(CheckIPOSupported)
+    check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
+
+    set(IPO_BUILD_ENABLED OFF PARENT_SCOPE)
+    if(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
+        message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
+        set(IPO_BUILD_ENABLED ON PARENT_SCOPE)
+    elseif(NOT IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
+        message(STATUS "IPO not supported: ${IPO_LOG}.")
+    endif()
+endfunction()
+
+# Sets appropriate IPO properties on target _target
+# if IPO is supported and enabled for the current build.
+function(ipo_set_target_properties _target)
+    if(IPO_BUILD_ENABLED)
+        set_property(TARGET ${_target} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+    endif()
+endfunction()
diff --git a/src/openrct2-cli/CMakeLists.txt b/src/openrct2-cli/CMakeLists.txt
index 441324fa44..e2c444fdf9 100644
--- a/src/openrct2-cli/CMakeLists.txt
+++ b/src/openrct2-cli/CMakeLists.txt
@@ -14,10 +14,7 @@ file(GLOB_RECURSE OPENRCT2_CLI_SOURCES
 set (PROJECT openrct2-cli)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_CLI_SOURCES})
-
-if(IPO_SUPPORTED)
-    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
-endif()
+ipo_set_target_properties(${PROJECT})
 
 target_link_libraries(${PROJECT} "libopenrct2")
 
diff --git a/src/openrct2-ui/CMakeLists.txt b/src/openrct2-ui/CMakeLists.txt
index 031b46f8c8..5f5e271a24 100644
--- a/src/openrct2-ui/CMakeLists.txt
+++ b/src/openrct2-ui/CMakeLists.txt
@@ -49,10 +49,7 @@ endif ()
 set (PROJECT openrct2)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_UI_SOURCES} ${OPENRCT2_UI_MM_SOURCES})
-
-if(IPO_SUPPORTED)
-    set_property(TARGET ${PROJECT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
-endif()
+ipo_set_target_properties(${PROJECT})
 
 target_link_libraries(${PROJECT} "libopenrct2"
                                  ${SDL2_LDFLAGS}

From 0789ef541d509161afc1322d8d02feb0b5e93975 Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sun, 27 Jan 2019 13:10:56 +0100
Subject: [PATCH 3/6] Add IPO override cmake option

---
 cmake/ipo.cmake | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/cmake/ipo.cmake b/cmake/ipo.cmake
index 5df2e9ef06..b760f3cddf 100644
--- a/cmake/ipo.cmake
+++ b/cmake/ipo.cmake
@@ -1,5 +1,7 @@
 # Helpers for inter-procedural optimizations (IPO)
 
+option(DISABLE_IPO "Disable IPO in supported release builds." OFF)
+
 # Enabled IPO for a LIST of CMake build types.
 # Provides IPO_BUILD_ENABLED to the parent scope.
 function(ipo_enable IPO_ENABLED_BUILDS)
@@ -8,8 +10,12 @@ function(ipo_enable IPO_ENABLED_BUILDS)
 
     set(IPO_BUILD_ENABLED OFF PARENT_SCOPE)
     if(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
-        message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
-        set(IPO_BUILD_ENABLED ON PARENT_SCOPE)
+        if(NOT DISABLE_IPO)
+            message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
+            set(IPO_BUILD_ENABLED ON PARENT_SCOPE)
+        else()
+            message(STATUS "IPO explicitly disabled.")
+        endif()
     elseif(NOT IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
         message(STATUS "IPO not supported: ${IPO_LOG}.")
     endif()

From 9186c8b7d9ade3315e42ec268322d5899a03d8b7 Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sun, 27 Jan 2019 13:23:36 +0100
Subject: [PATCH 4/6] Check for unset CMAKE_BUILD_TYPE

---
 cmake/ipo.cmake | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cmake/ipo.cmake b/cmake/ipo.cmake
index b760f3cddf..ce54b0e381 100644
--- a/cmake/ipo.cmake
+++ b/cmake/ipo.cmake
@@ -9,7 +9,9 @@ function(ipo_enable IPO_ENABLED_BUILDS)
     check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
 
     set(IPO_BUILD_ENABLED OFF PARENT_SCOPE)
-    if(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
+    if(NOT CMAKE_BUILD_TYPE)
+        message(STATUS "CMAKE_BUILD_TYPE not explicitly set. Not enabling IPO.")
+    elseif(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
         if(NOT DISABLE_IPO)
             message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
             set(IPO_BUILD_ENABLED ON PARENT_SCOPE)

From b1bc3d93223ee27eba9c1e97525e3293e522a59b Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sun, 27 Jan 2019 13:44:16 +0100
Subject: [PATCH 5/6] Make build type check case insensitive

---
 CMakeLists.txt  | 2 +-
 cmake/ipo.cmake | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6850784e8d..b6cb7c657a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,7 +53,7 @@ if (PORTABLE OR WIN32)
 endif ()
 
 include(cmake/ipo.cmake)
-list(APPEND IPO_ENABLED_BUILDS Release RelWithDebInfo MinSizeRel)
+list(APPEND IPO_ENABLED_BUILDS RELEASE RELWITHDEBINFO MINSIZEREL)
 ipo_enable("${IPO_ENABLED_BUILDS}")
 
 # Describe current version in terms of closest tag
diff --git a/cmake/ipo.cmake b/cmake/ipo.cmake
index ce54b0e381..7c77c62a20 100644
--- a/cmake/ipo.cmake
+++ b/cmake/ipo.cmake
@@ -4,21 +4,23 @@ option(DISABLE_IPO "Disable IPO in supported release builds." OFF)
 
 # Enabled IPO for a LIST of CMake build types.
 # Provides IPO_BUILD_ENABLED to the parent scope.
+# Make sure to supply the build types in UPPER CASE
 function(ipo_enable IPO_ENABLED_BUILDS)
     include(CheckIPOSupported)
     check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_LOG)
 
     set(IPO_BUILD_ENABLED OFF PARENT_SCOPE)
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_UPPER)
     if(NOT CMAKE_BUILD_TYPE)
         message(STATUS "CMAKE_BUILD_TYPE not explicitly set. Not enabling IPO.")
-    elseif(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
+    elseif(IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE_UPPER} IN_LIST IPO_ENABLED_BUILDS)
         if(NOT DISABLE_IPO)
             message(STATUS "IPO supported and enabled in ${CMAKE_BUILD_TYPE}.")
             set(IPO_BUILD_ENABLED ON PARENT_SCOPE)
         else()
             message(STATUS "IPO explicitly disabled.")
         endif()
-    elseif(NOT IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE} IN_LIST IPO_ENABLED_BUILDS)
+    elseif(NOT IPO_SUPPORTED AND ${CMAKE_BUILD_TYPE_UPPER} IN_LIST IPO_ENABLED_BUILDS)
         message(STATUS "IPO not supported: ${IPO_LOG}.")
     endif()
 endfunction()

From ce6e08c63367acb6808413c4694b1e9f693ce25a Mon Sep 17 00:00:00 2001
From: Tom Lankhorst <hello@tomlankhorst.nl>
Date: Sun, 3 Feb 2019 23:32:51 +0100
Subject: [PATCH 6/6] Introduce SET_CHECK_CXX_FLAGS

---
 CMakeLists.txt                 | 65 ++++++++++++++++++----------------
 src/openrct2-ui/CMakeLists.txt |  1 +
 src/openrct2/CMakeLists.txt    |  1 +
 test/testpaint/CMakeLists.txt  |  1 +
 test/tests/CMakeLists.txt      | 10 ++++++
 5 files changed, 47 insertions(+), 31 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b6cb7c657a..6338c54611 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,6 +52,10 @@ if (PORTABLE OR WIN32)
     set(CMAKE_INSTALL_RPATH "$ORIGIN")
 endif ()
 
+# LIST of supported flags, use SET_CHECK_CXX_FLAGS() to apply to target.
+# Use ADD_CHECK_CXX_COMPILER_FLAG() to add to list.
+list(APPEND SUPPORTED_CHECK_CXX_COMPILER_FLAGS)
+
 include(cmake/ipo.cmake)
 list(APPEND IPO_ENABLED_BUILDS RELEASE RELWITHDEBINFO MINSIZEREL)
 ipo_enable("${IPO_ENABLED_BUILDS}")
@@ -137,45 +141,21 @@ elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "i686.*|i386.*|x86.*|amd64.*|AMD64.*")
     set(X86 1)
 endif()
 
-# Include sub-projects
-include("${ROOT_DIR}/src/openrct2/CMakeLists.txt" NO_POLICY_SCOPE)
-include("${ROOT_DIR}/src/openrct2-cli/CMakeLists.txt" NO_POLICY_SCOPE)
-if(NOT DISABLE_GUI)
-    include("${ROOT_DIR}/src/openrct2-ui/CMakeLists.txt" NO_POLICY_SCOPE)
-endif()
-
-# g2
-add_custom_command(
-    OUTPUT g2.dat
-    COMMAND ./openrct2-cli sprite build \"${CMAKE_BINARY_DIR}/g2.dat\" \"${ROOT_DIR}/resources/g2/sprites.json\"
-    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-)
-add_custom_target(g2 DEPENDS ${PROJECT} g2.dat)
-
-# Include tests
-if (WITH_TESTS)
-    enable_testing()
-    if (UNIX AND (NOT USE_MMAP))
-        include("${ROOT_DIR}/test/testpaint/CMakeLists.txt" NO_POLICY_SCOPE)
-    endif ()
-    include("${ROOT_DIR}/test/tests/CMakeLists.txt" NO_POLICY_SCOPE)
-endif ()
-
-# Check if a flag exists and add it to the compiler (so, not the linker) options
+# Check if a flag exists and add it to the list of compiler (so, not linker) options
 function (ADD_CHECK_CXX_COMPILER_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
     CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
     if (${_CACHE_VAR})
-        if(TARGET ${PROJECT})
-            target_compile_options(${PROJECT} PRIVATE ${_FLAG})
-        endif()
-        if(TARGET ${PROJECT}-cli)
-            target_compile_options(${PROJECT}-cli PRIVATE ${_FLAG})
-        endif()
+        list(APPEND SUPPORTED_CHECK_CXX_COMPILER_FLAGS "${_FLAG}")
     else ()
         message(STATUS "Unsupported CXXFLAG: ${_FLAG}")
     endif ()
 endfunction ()
 
+# Add check flags to a compile TARGET
+function (SET_CHECK_CXX_FLAGS _TARGET)
+    target_compile_options("${_TARGET}" PRIVATE "${SUPPORTED_CHECK_CXX_COMPILER_FLAGS}")
+endfunction()
+
 # Check if a flag exists and add it to the compiler and the linker options
 function (ADD_CHECK_CXX_FLAG _CXXFLAGS _CACHE_VAR _FLAG)
     CHECK_CXX_COMPILER_FLAG("${_FLAG}" "${_CACHE_VAR}")
@@ -248,6 +228,29 @@ else ()
     endif ()
 endif ()
 
+# Include sub-projects
+include("${ROOT_DIR}/src/openrct2/CMakeLists.txt" NO_POLICY_SCOPE)
+include("${ROOT_DIR}/src/openrct2-cli/CMakeLists.txt" NO_POLICY_SCOPE)
+if(NOT DISABLE_GUI)
+    include("${ROOT_DIR}/src/openrct2-ui/CMakeLists.txt" NO_POLICY_SCOPE)
+endif()
+
+# g2
+add_custom_command(
+    OUTPUT g2.dat
+    COMMAND ./openrct2-cli sprite build \"${CMAKE_BINARY_DIR}/g2.dat\" \"${ROOT_DIR}/resources/g2/sprites.json\"
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+)
+add_custom_target(g2 DEPENDS ${PROJECT} g2.dat)
+
+# Include tests
+if (WITH_TESTS)
+    enable_testing()
+    if (UNIX AND (NOT USE_MMAP))
+        include("${ROOT_DIR}/test/testpaint/CMakeLists.txt" NO_POLICY_SCOPE)
+    endif ()
+    include("${ROOT_DIR}/test/tests/CMakeLists.txt" NO_POLICY_SCOPE)
+endif ()
 
 # Install
 # Don't recurse, grab all *.txt and *.md files
diff --git a/src/openrct2-ui/CMakeLists.txt b/src/openrct2-ui/CMakeLists.txt
index 5f5e271a24..52bd7a62b9 100644
--- a/src/openrct2-ui/CMakeLists.txt
+++ b/src/openrct2-ui/CMakeLists.txt
@@ -49,6 +49,7 @@ endif ()
 set (PROJECT openrct2)
 project(${PROJECT} CXX)
 add_executable(${PROJECT} ${OPENRCT2_UI_SOURCES} ${OPENRCT2_UI_MM_SOURCES})
+SET_CHECK_CXX_FLAGS(${PROJECT})
 ipo_set_target_properties(${PROJECT})
 
 target_link_libraries(${PROJECT} "libopenrct2"
diff --git a/src/openrct2/CMakeLists.txt b/src/openrct2/CMakeLists.txt
index 0471db4717..1bec314524 100644
--- a/src/openrct2/CMakeLists.txt
+++ b/src/openrct2/CMakeLists.txt
@@ -74,6 +74,7 @@ set(PROJECT libopenrct2)
 project(${PROJECT} CXX)
 add_library(${PROJECT} ${OPENRCT2_CORE_SOURCES} ${OPENRCT2_CORE_MM_SOURCES} ${RCT2_SECTIONS})
 set_target_properties(${PROJECT} PROPERTIES PREFIX "")
+SET_CHECK_CXX_FLAGS(${PROJECT})
 
 if (benchmark_FOUND)
     message("Found Google benchmark, enabling support")
diff --git a/test/testpaint/CMakeLists.txt b/test/testpaint/CMakeLists.txt
index 83faee5fef..11c56ba2e1 100644
--- a/test/testpaint/CMakeLists.txt
+++ b/test/testpaint/CMakeLists.txt
@@ -83,6 +83,7 @@ file(GLOB_RECURSE ORCT2_TESTPAINT_SOURCES "${CMAKE_CURRENT_LIST_DIR}/*.c"
 set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/addresses.c PROPERTIES COMPILE_FLAGS -O0)
 
 add_executable(testpaint EXCLUDE_FROM_ALL ${ORCT2_RIDE_SOURCES} ${ORCT2_RIDE_DEP_SOURCES} ${ORCT2_TESTPAINT_SOURCES} ${RCT2_SECTIONS})
+SET_CHECK_CXX_FLAGS(testpaint)
 target_include_directories(testpaint PRIVATE "${ROOT_DIR}/src/")
 target_link_libraries(testpaint z)
 
diff --git a/test/tests/CMakeLists.txt b/test/tests/CMakeLists.txt
index 25d946547b..c8f2c923e0 100644
--- a/test/tests/CMakeLists.txt
+++ b/test/tests/CMakeLists.txt
@@ -137,6 +137,7 @@ set(INI_TEST_SOURCES
         "${ROOT_DIR}/src/openrct2/core/MemoryStream.cpp"
         )
 add_executable(test_ini ${INI_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_ini)
 target_link_libraries(test_ini ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME ini COMMAND test_ini)
 
@@ -145,12 +146,14 @@ set(STRING_TEST_SOURCES
         "${CMAKE_CURRENT_LIST_DIR}/StringTest.cpp"
         )
 add_executable(test_string ${STRING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_string)
 target_link_libraries(test_string ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME string COMMAND test_string)
 
 # Localisation test
 set(STRING_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/Localisation.cpp")
 add_executable(test_localisation ${STRING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_localisation)
 target_link_libraries(test_localisation ${GTEST_LIBRARIES} test-common ${LDL} z)
 add_test(NAME localisation COMMAND test_localisation)
 
@@ -158,6 +161,7 @@ if (NOT DISABLE_NETWORK)
     # Crypt tests
     add_executable(test_crypt "${CMAKE_CURRENT_LIST_DIR}/CryptTests.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
+    SET_CHECK_CXX_FLAGS(test_crypt)
     target_link_libraries(test_crypt ${GTEST_LIBRARIES} libopenrct2)
     add_test(NAME Crypt COMMAND test_crypt)
 endif ()
@@ -165,6 +169,7 @@ endif ()
 # ImageImporter tests
 add_executable(test_imageimporter "${CMAKE_CURRENT_LIST_DIR}/ImageImporterTests.cpp"
                                   "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
+SET_CHECK_CXX_FLAGS(test_imageimporter)
 target_link_libraries(test_imageimporter ${GTEST_LIBRARIES} libopenrct2)
 add_test(NAME ImageImporter COMMAND test_imageimporter)
 
@@ -172,6 +177,7 @@ add_test(NAME ImageImporter COMMAND test_imageimporter)
 set(RIDE_RATINGS_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/RideRatings.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_ride_ratings ${RIDE_RATINGS_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_ride_ratings)
 target_link_libraries(test_ride_ratings ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME ride_ratings COMMAND test_ride_ratings)
 
@@ -179,6 +185,7 @@ add_test(NAME ride_ratings COMMAND test_ride_ratings)
 set(MULTILAUNCH_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/MultiLaunch.cpp"
                              "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_multilaunch ${MULTILAUNCH_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_multilaunch)
 target_link_libraries(test_multilaunch ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME multilaunch COMMAND test_multilaunch)
 
@@ -186,6 +193,7 @@ add_test(NAME multilaunch COMMAND test_multilaunch)
 set(TILE_ELEMENT_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/TileElements.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_tile_elements ${TILE_ELEMENT_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_tile_elements)
 target_link_libraries(test_tile_elements ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME tile_elements COMMAND test_tile_elements)
 
@@ -194,6 +202,7 @@ if (NOT DISABLE_NETWORK)
     set(REPLAY_TEST_SOURCES "${CMAKE_CURRENT_LIST_DIR}/ReplayTests.cpp"
                                   "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
     add_executable(test_replays ${REPLAY_TEST_SOURCES})
+    SET_CHECK_CXX_FLAGS(test_replays)
     target_link_libraries(test_replays ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
     add_test(NAME replay_tests COMMAND test_replays)
 endif ()
@@ -202,5 +211,6 @@ endif ()
 set(PATHFINDING_TEST_SOURCES  "${CMAKE_CURRENT_LIST_DIR}/Pathfinding.cpp"
                               "${CMAKE_CURRENT_LIST_DIR}/TestData.cpp")
 add_executable(test_pathfinding ${PATHFINDING_TEST_SOURCES})
+SET_CHECK_CXX_FLAGS(test_pathfinding)
 target_link_libraries(test_pathfinding ${GTEST_LIBRARIES} libopenrct2 ${LDL} z)
 add_test(NAME pathfinding COMMAND test_pathfinding)