cmake: set required C/C++ standard to 11

Co-authored-by: Jason Rhinelander <jason@imaginary.ca>

4 files changed, 26 insertions, 13 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 83956f68e..92c93be47 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,6 +57,14 @@ endif()
 
 enable_language(C ASM)
 
+# Require C11/C++11 and disable extensions for all targets
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_C_EXTENSIONS OFF)
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
 function (die msg)
   if (NOT WIN32)
     string(ASCII 27 Esc)
@@ -493,7 +501,7 @@ if (CMAKE_SYSTEM_NAME MATCHES "(SunOS|Solaris)")
 endif ()
 
 if (APPLE AND NOT IOS)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=default -std=c++11")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=default")
   if (NOT OPENSSL_ROOT_DIR)
       EXECUTE_PROCESS(COMMAND brew --prefix openssl
         OUTPUT_VARIABLE OPENSSL_ROOT_DIR
@@ -675,14 +683,14 @@ else()
   endif()
   set(C_WARNINGS "-Waggregate-return -Wnested-externs -Wold-style-definition -Wstrict-prototypes")
   set(CXX_WARNINGS "-Wno-reorder -Wno-missing-field-initializers")
-  try_compile(STATIC_ASSERT_RES "${CMAKE_CURRENT_BINARY_DIR}/static-assert" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/test-static-assert.c" COMPILE_DEFINITIONS "-std=c11")
+  try_compile(STATIC_ASSERT_RES "${CMAKE_CURRENT_BINARY_DIR}/static-assert" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/test-static-assert.c" CMAKE_FLAGS -DCMAKE_C_STANDARD=11)
   if(STATIC_ASSERT_RES)
     set(STATIC_ASSERT_FLAG "")
   else()
     set(STATIC_ASSERT_FLAG "-Dstatic_assert=_Static_assert")
   endif()
 
-  try_compile(STATIC_ASSERT_CPP_RES "${CMAKE_CURRENT_BINARY_DIR}/static-assert" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/test-static-assert.cpp" COMPILE_DEFINITIONS "-std=c++11")
+  try_compile(STATIC_ASSERT_CPP_RES "${CMAKE_CURRENT_BINARY_DIR}/static-assert" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/test-static-assert.cpp" CMAKE_FLAGS -DCMAKE_CXX_STANDARD=11)
   if(STATIC_ASSERT_CPP_RES)
     set(STATIC_ASSERT_CPP_FLAG "")
   else()
@@ -771,8 +779,8 @@ else()
   message(STATUS "Using C++ security hardening flags: ${CXX_SECURITY_FLAGS}")
   message(STATUS "Using linker security hardening flags: ${LD_SECURITY_FLAGS}")
 
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11 -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_FLAG} ${WARNINGS} ${C_WARNINGS} ${COVERAGE_FLAGS} ${PIC_FLAG} ${C_SECURITY_FLAGS}")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_CPP_FLAG} ${WARNINGS} ${CXX_WARNINGS} ${COVERAGE_FLAGS} ${PIC_FLAG} ${CXX_SECURITY_FLAGS}")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_FLAG} ${WARNINGS} ${C_WARNINGS} ${COVERAGE_FLAGS} ${PIC_FLAG} ${C_SECURITY_FLAGS}")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_CPP_FLAG} ${WARNINGS} ${CXX_WARNINGS} ${COVERAGE_FLAGS} ${PIC_FLAG} ${CXX_SECURITY_FLAGS}")
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${LD_SECURITY_FLAGS} ${LD_BACKCOMPAT_FLAGS}")
 
   # With GCC 6.1.1 the compiled binary malfunctions due to aliasing. Until that
@@ -1122,8 +1130,6 @@ option(BUILD_GUI_DEPS "Build GUI dependencies." OFF)
 option(INSTALL_VENDORED_LIBUNBOUND "Install libunbound binary built from source vendored with this repo." OFF)
 
 
-CHECK_C_COMPILER_FLAG(-std=c11 HAVE_C11)
-
 find_package(PythonInterp)
 find_program(iwyu_tool_path NAMES iwyu_tool.py iwyu_tool)
 if (iwyu_tool_path AND PYTHONINTERP_FOUND)
diff --git a/contrib/epee/src/CMakeLists.txt b/contrib/epee/src/CMakeLists.txt
index bdb3498c0..15e7687e3 100644
--- a/contrib/epee/src/CMakeLists.txt
+++ b/contrib/epee/src/CMakeLists.txt
@@ -35,9 +35,7 @@ if (USE_READLINE AND (GNU_READLINE_FOUND OR (DEPENDS AND NOT MINGW)))
   add_library(epee_readline STATIC readline_buffer.cpp)
 endif()
 
-if(HAVE_C11)
-SET_PROPERTY(SOURCE memwipe.c PROPERTY COMPILE_FLAGS -std=c11)
-endif()
+set_property(SOURCE memwipe.c PROPERTY C_STANDARD 11)
 
 # Build and install libepee if we're building for GUI
 if (BUILD_GUI_DEPS)
diff --git a/contrib/epee/tests/src/CMakeLists.txt b/contrib/epee/tests/src/CMakeLists.txt
index 4807fa7ea..026ed0a26 100644
--- a/contrib/epee/tests/src/CMakeLists.txt
+++ b/contrib/epee/tests/src/CMakeLists.txt
@@ -1,6 +1,13 @@
 
 cmake_minimum_required(VERSION 2.8)
 
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+set(CMAKE_C_EXTENSIONS OFF)
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
 set(Boost_USE_MULTITHREADED ON)
 
 include_directories(.)
@@ -14,8 +21,8 @@ IF (MSVC)
 	include_directories(SYSTEM platform/msvc)
 ELSE()
 	# set stuff for other systems
-	SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11 -Wall")
-	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wall -Wno-reorder")
+	SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wno-reorder")
 ENDIF()
 
 
diff --git a/external/easylogging++/CMakeLists.txt b/external/easylogging++/CMakeLists.txt
index 35fb86552..ab1e571a8 100644
--- a/external/easylogging++/CMakeLists.txt
+++ b/external/easylogging++/CMakeLists.txt
@@ -30,7 +30,9 @@ cmake_minimum_required(VERSION 2.8.7)
 
 project(easylogging CXX)
 
-SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
 find_package(Threads)
 find_package(Backtrace)