From 90d66ea4a9214d53bbb6acbe098409c4d739167e Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Thu, 11 Feb 2016 22:15:46 +0100
Subject: [PATCH] cmake: fix detection of -Werror flag

Do not use minus sign in macro names.
---
 CMakeLists.txt                | 10 ++++------
 cmake/ExtractValidFlags.cmake |  4 ++--
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06719bf8..d435512e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -106,11 +106,10 @@ else()
   add_definitions(-D_U_ -DNGHTTP2_NORETURN)
 endif()
 
-include(CheckCXXCompilerFlag)
-foreach(_std gnu++11 gnu++0x)
-  set(_cxx1x_flag -std=${_std})
-  check_cxx_compiler_flag(${_cxx1x_flag} CXX_FLAG_-std_${_std})
-  if(CXX_FLAG_-std_${_std})
+include(ExtractValidFlags)
+foreach(_cxx1x_flag -std=gnu++11 -std=gnu++0x)
+  extract_valid_cxx_flags(_cxx1x_flag_supported ${_cxx1x_flag})
+  if(_cxx1x_flag_supported)
     set(CXX1XCXXFLAGS ${_cxx1x_flag})
     break()
   endif()
@@ -381,7 +380,6 @@ if(HAVE_EPOLL AND HAVE_TIMERFD_CREATE)
   set(ENABLE_TINY_NGHTTPD 1)
 endif()
 
-include(ExtractValidFlags)
 if(ENABLE_WERROR)
   # For C compiler
   extract_valid_c_flags(WARNCFLAGS
diff --git a/cmake/ExtractValidFlags.cmake b/cmake/ExtractValidFlags.cmake
index 47a6c2b2..3b0b0240 100644
--- a/cmake/ExtractValidFlags.cmake
+++ b/cmake/ExtractValidFlags.cmake
@@ -7,7 +7,7 @@ include(CheckCXXCompilerFlag)
 function(extract_valid_c_flags varname)
   set(valid_flags "")
   foreach(flag IN LISTS ARGN)
-    string(REGEX REPLACE "[^a-zA-Z0-9_-]+" "_" flag_var ${flag})
+    string(REGEX REPLACE "[^a-zA-Z0-9_]+" "_" flag_var ${flag})
     set(flag_var "C_FLAG_${flag_var}")
     check_c_compiler_flag("${flag}" "${flag_var}")
     if(${flag_var})
@@ -20,7 +20,7 @@ endfunction()
 function(extract_valid_cxx_flags varname)
   set(valid_flags "")
   foreach(flag IN LISTS ARGN)
-    string(REGEX REPLACE "[^a-zA-Z0-9_-]+" "_" flag_var ${flag})
+    string(REGEX REPLACE "[^a-zA-Z0-9_]+" "_" flag_var ${flag})
     set(flag_var "CXX_FLAG_${flag_var}")
     check_cxx_compiler_flag("${flag}" "${flag_var}")
     if(${flag_var})