disable pch messages when Wno-pch-messages flag exists

CMake/cotire.cmake

@@ -1657,6 +1657,10 @@ function (cotire_add_pch_compilation_flags _language _compilerID _compilerVersio
 			get_filename_component(_pchName "${_pchFile}" NAME)
 			set (_xLanguage_C "c-header")
 			set (_xLanguage_CXX "c++-header")
+			set (_pchSuppressMessages FALSE)
+			if ("${CMAKE_${_language}_FLAGS}" MATCHES ".*-Wno-pch-messages.*")
+				set(_pchSuppressMessages TRUE)
+			endif()
 			if (_flags)
 				# append to list
 				if ("${_language}" STREQUAL "CXX")
@@ -1664,13 +1668,17 @@ function (cotire_add_pch_compilation_flags _language _compilerID _compilerVersio
 				endif()
 				list (APPEND _flags "-include" "${_prefixFile}" "-pch-dir" "${_pchDir}" "-pch-create" "${_pchName}" "-fsyntax-only" "${_hostFile}")
 				if (NOT "${_compilerVersion}" VERSION_LESS "13.1.0")
-					list (APPEND _flags "-Wpch-messages")
+					if (NOT _pchSuppressMessages)
+						list (APPEND _flags "-Wpch-messages")
+					endif()
 				endif()
 			else()
 				# return as a flag string
 				set (_flags "-include \"${_prefixFile}\" -pch-dir \"${_pchDir}\" -pch-create \"${_pchName}\"")
 				if (NOT "${_compilerVersion}" VERSION_LESS "13.1.0")
-					set (_flags "${_flags} -Wpch-messages")
+					if (NOT _pchSuppressMessages)
+						set (_flags "${_flags} -Wpch-messages")
+					endif()
 				endif()
 			endif()
 		endif()
@@ -1781,17 +1789,25 @@ function (cotire_add_prefix_pch_inclusion_flags _language _compilerID _compilerV
 			if (_pchFile)
 				get_filename_component(_pchDir "${_pchFile}" DIRECTORY)
 				get_filename_component(_pchName "${_pchFile}" NAME)
+				set (_pchSuppressMessages FALSE)
+				if ("${CMAKE_${_language}_FLAGS}" MATCHES ".*-Wno-pch-messages.*")
+					set(_pchSuppressMessages TRUE)
+				endif()
 				if (_flags)
 					# append to list
 					list (APPEND _flags "-include" "${_prefixFile}" "-pch-dir" "${_pchDir}" "-pch-use" "${_pchName}")
 					if (NOT "${_compilerVersion}" VERSION_LESS "13.1.0")
-						list (APPEND _flags "-Wpch-messages")
+						if (NOT _pchSuppressMessages)
+							list (APPEND _flags "-Wpch-messages")
+						endif()
 					endif()
 				else()
 					# return as a flag string
 					set (_flags "-include \"${_prefixFile}\" -pch-dir \"${_pchDir}\" -pch-use \"${_pchName}\"")
 					if (NOT "${_compilerVersion}" VERSION_LESS "13.1.0")
-						set (_flags "${_flags} -Wpch-messages")
+						if (NOT _pchSuppressMessages)
+							set (_flags "${_flags} -Wpch-messages")
+						endif()
 					endif()
 				endif()
 			else()