commit a928171ff42fb4b61c2b90d43f9a546498af6df9
author David Benjamin <davidben@google.com> Fri May 20 12:41:15 2022 -0400
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon May 23 20:45:42 2022 +0000
tree b5c58404817f9c79b44eb209210731b596f4f7c7
parent ac639b76b4d1c9d9b7dd1cfcd2314de5693655c9

Use CMake's C/C++ version features.

This seems to be the preferred mechanism starting CMake 3.1, and reduces
some compiler-specific bits. We can probably also retire -stdlib=libc++
on AppleClang now. https://boringssl-review.googlesource.com/21984
suggests it was needed to make C++11 work, but presumably that's the
default stdlib now that the default C++ version is C++11.

(If it is needed, that ought to be CMAKE_CXX_STANDARD's responsibility.
I don't see any evidence of them setting it, so I'm guessing this is
just no longer needed.)

Change-Id: Ide1fdbd3d4b8fe37a10a7948171a2c20c9de21f9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/52647
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 202681d..aadcb9b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -122,6 +122,13 @@
   set(EMSCRIPTEN 1)
 endif()
 
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+if(MSVC AND NOT CLANG)
+  set(CMAKE_C_STANDARD 11)
+  set(CMAKE_C_STANDARD_REQUIRED ON)
+endif()
+
 if(CMAKE_COMPILER_IS_GNUCXX OR CLANG)
   # Note clang-cl is odd and sets both CLANG and MSVC. We base our configuration
   # primarily on our normal Clang one.
@@ -164,14 +171,8 @@
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${C_CXX_FLAGS} -Wmissing-prototypes -Wold-style-definition -Wstrict-prototypes")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${C_CXX_FLAGS} -Wmissing-declarations")
 
-  if(NOT MSVC)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
-    if(APPLE)
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
-    endif()
-    if(NOT BORINGSSL_ALLOW_CXX_RUNTIME)
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-exceptions -fno-rtti")
-    endif()
+  if(NOT MSVC AND NOT BORINGSSL_ALLOW_CXX_RUNTIME)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-exceptions -fno-rtti")
   endif()
 
   # In GCC, -Wmissing-declarations is the C++ spelling of -Wmissing-prototypes
@@ -261,10 +262,6 @@
   add_definitions("-D_STL_EXTRA_DISABLED_WARNINGS=4774 4987")
 endif()
 
-if(CMAKE_COMPILER_IS_GNUCXX)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c11")
-endif()
-
 # pthread_rwlock_t on Linux requires a feature flag. We limit this to Linux
 # because, on Apple platforms, it instead disables APIs we use. See compat(5)
 # and sys/cdefs.h. Reportedly, FreeBSD also breaks when this is set. See