From aa86191fd81003ce3e8033fb95daf8b2cffe94c9 Mon Sep 17 00:00:00 2001
From: cDc <cdc.seacave@gmail.com>
Date: Mon, 9 Sep 2024 11:50:10 +0300
Subject: [PATCH] common: refactor CUDA support in CMake

(cherry picked from commit b96dd573680262e6b94f6d7e53d80c994074cc96)
---
 CMakeLists.txt    | 35 ++++++++++++++++++++++-------------
 build/Utils.cmake | 21 +++++++++++++--------
 2 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 87534d7e2..b9d301cba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,16 +3,22 @@
 ########################################################################
 #
 # Project-wide settings
-CMAKE_MINIMUM_REQUIRED(VERSION 3.8.2)
+CMAKE_MINIMUM_REQUIRED(VERSION 3.10)
 IF(POLICY CMP0011)
 	CMAKE_POLICY(SET CMP0011 NEW)
 ENDIF()
+IF(POLICY CMP0072)
+	CMAKE_POLICY(SET CMP0072 NEW)
+ENDIF()
 IF(POLICY CMP0074)
 	CMAKE_POLICY(SET CMP0074 NEW)
 ENDIF()
 IF(POLICY CMP0104)
 	CMAKE_POLICY(SET CMP0104 NEW)
 ENDIF()
+IF(POLICY CMP0146)
+	CMAKE_POLICY(SET CMP0146 OLD) # not required, but forced by OpenCV old support for CUDA
+ENDIF()
 
 # List configuration options
 SET(OpenMVS_BUILD_TOOLS ON CACHE BOOL "Build example applications")
@@ -49,14 +55,14 @@ ENDIF()
 # CMake files in this project can refer to the root source directory
 # as ${OpenMVS_SOURCE_DIR} and to the root binary directory as
 # ${OpenMVS_BINARY_DIR}.
-PROJECT(OpenMVS)
+PROJECT(OpenMVS LANGUAGES CXX)
 
 SET(OpenMVS_MAJOR_VERSION 2)
 SET(OpenMVS_MINOR_VERSION 3)
 SET(OpenMVS_PATCH_VERSION 0)
 SET(OpenMVS_VERSION ${OpenMVS_MAJOR_VERSION}.${OpenMVS_MINOR_VERSION}.${OpenMVS_PATCH_VERSION})
 
-# Disable SSE on unsuported platforms
+# Disable SSE on unsupported platforms
 IF(CMAKE_SYSTEM_PROCESSOR MATCHES "^(arm|ARM|aarch64|AARCH64)")
 	SET(OpenMVS_USE_SSE OFF)
 ENDIF()
@@ -95,9 +101,6 @@ if(OpenMVS_USE_OPENMP)
 endif()
 
 if(OpenMVS_USE_OPENGL)
-	if(POLICY CMP0072)
-		cmake_policy(SET CMP0072 NEW)
-	endif()
 	FIND_PACKAGE(OpenGL)
 	if(OPENGL_FOUND)
 		INCLUDE_DIRECTORIES(${OPENGL_INCLUDE_DIR})
@@ -109,15 +112,20 @@ if(OpenMVS_USE_OPENGL)
 endif()
 
 if(OpenMVS_USE_CUDA)
-	if(POLICY CMP0146)
-		cmake_policy(SET CMP0146 NEW)
-	endif()
-	FIND_PACKAGE(CUDA)
-	if(CUDA_FOUND)
+	INCLUDE(CheckLanguage)
+	CHECK_LANGUAGE(CUDA)
+	if(CMAKE_CUDA_COMPILER)
+		SET(CUDA_FOUND TRUE)
+		if(NOT DEFINED CMAKE_CUDA_ARCHITECTURES)
+			SET(CMAKE_CUDA_ARCHITECTURES "native")
+		endif()
 		ENABLE_LANGUAGE(CUDA)
+		# not required, but forced by OpenCV old support for CUDA
+		FIND_PACKAGE(CUDA REQUIRED)
 		# CUDA-11.x can not be compiled using C++14 standard on Windows
-		string(REGEX MATCH "^[0-9]+" CUDA_MAJOR ${CMAKE_CUDA_COMPILER_VERSION})
-		if(${CUDA_MAJOR} GREATER 10)
+		string(REGEX MATCH "^[0-9]+" CUDA_VERSION_MAJOR ${CMAKE_CUDA_COMPILER_VERSION})
+		string(REGEX REPLACE "([0-9]+)\\.([0-9]+).*" "\\2" CUDA_VERSION_MINOR ${CMAKE_CUDA_COMPILER_VERSION})
+		if(${CUDA_VERSION_MAJOR} GREATER 10)
 			SET(CMAKE_CUDA_STANDARD 17)
 		endif()
 		EXECUTE_PROCESS(COMMAND "${CMAKE_CUDA_COMPILER}" --list-gpu-arch 
@@ -159,6 +167,7 @@ if(OpenMVS_USE_CUDA)
 		SET(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --expt-relaxed-constexpr")
 		INCLUDE_DIRECTORIES(${CUDA_INCLUDE_DIRS})
 		SET(_USE_CUDA TRUE)
+		MESSAGE("-- Found CUDA: " ${CMAKE_CUDA_COMPILER_VERSION} " with GPU arch: " ${CMAKE_CUDA_ARCHITECTURES})
 	else()
 		SET(CUDA_CUDA_LIBRARY "")
 		MESSAGE("-- Can't find CUDA. Continuing without it.")
diff --git a/build/Utils.cmake b/build/Utils.cmake
index 6f724b2b4..61a2fcc0c 100644
--- a/build/Utils.cmake
+++ b/build/Utils.cmake
@@ -360,14 +360,17 @@ macro(add_extra_compiler_option option)
   if(CMAKE_BUILD_TYPE)
     set(CMAKE_TRY_COMPILE_CONFIGURATION ${CMAKE_BUILD_TYPE})
   endif()
-  _check_flag_support(CXX "${option}" _varname "${BUILD_EXTRA_CXX_FLAGS} ${ARGN}")
-  if(${_varname})
-    set(BUILD_EXTRA_CXX_FLAGS "${BUILD_EXTRA_CXX_FLAGS} ${option}")
+  if(CMAKE_CXX_COMPILER_ID)
+    _check_flag_support(CXX "${option}" _varname "${BUILD_EXTRA_CXX_FLAGS} ${ARGN}")
+    if(${_varname})
+      set(BUILD_EXTRA_CXX_FLAGS "${BUILD_EXTRA_CXX_FLAGS} ${option}")
+    endif()
   endif()
-
-  _check_flag_support(C "${option}" _varname "${BUILD_EXTRA_C_FLAGS} ${ARGN}")
-  if(${_varname})
-    set(BUILD_EXTRA_C_FLAGS "${BUILD_EXTRA_C_FLAGS} ${option}")
+  if(CMAKE_C_COMPILER_ID)
+    _check_flag_support(C "${option}" _varname "${BUILD_EXTRA_C_FLAGS} ${ARGN}")
+    if(${_varname})
+      set(BUILD_EXTRA_C_FLAGS "${BUILD_EXTRA_C_FLAGS} ${option}")
+    endif()
   endif()
 endmacro()
 
@@ -707,7 +710,9 @@ macro(optimize_default_compiler_settings)
 		string(REPLACE "/Zm1000" "" ${flags} "${${flags}}")
 	  endforeach()
 	endif()
-	CHECK_INCLUDE_FILE("inttypes.h" HAVE_INTTYPES_H)
+	if(CMAKE_C_COMPILER_ID)
+		CHECK_INCLUDE_FILE("inttypes.h" HAVE_INTTYPES_H)
+	endif()
 endmacro()