From 31e992a2850450121199169f8538f28b2f634cd7 Mon Sep 17 00:00:00 2001
From: Josh Blum
Date: Wed, 8 Aug 2012 18:32:40 -0700
Subject: volk: special werror unused cmd line arg for clang

---
 volk/lib/CMakeLists.txt | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/volk/lib/CMakeLists.txt b/volk/lib/CMakeLists.txt
index 8288786c9..2ba1bf8fd 100644
--- a/volk/lib/CMakeLists.txt
+++ b/volk/lib/CMakeLists.txt
@@ -54,6 +54,17 @@ if(NOT DEFINED COMPILER_NAME)
     message(FATAL_ERROR "COMPILER_NAME undefined. Volk build may not support this compiler.")
 endif()
 
+########################################################################
+# Special clang flag so flag checks can fail
+########################################################################
+if(COMPILER_NAME MATCHES "GNU")
+    include(CheckCXXCompilerFlag)
+    CHECK_CXX_COMPILER_FLAG("-Werror=unused-command-line-argument" HAVE_WERROR_UNUSED_CMD_LINE_ARG)
+    if(HAVE_WERROR_UNUSED_CMD_LINE_ARG)
+        set(VOLK_FLAG_CHECK_FLAGS "-Werror=unused-command-line-argument")
+    endif()
+endif()
+
 ########################################################################
 # detect x86 flavor of CPU
 ########################################################################
@@ -82,7 +93,9 @@ macro(check_arch arch_name)
             COMMAND ${PYTHON_EXECUTABLE} -c "import re; print(re.sub('\\W', '_', '${have_flag}'))"
             OUTPUT_VARIABLE have_flag OUTPUT_STRIP_TRAILING_WHITESPACE
         )
+        set(CMAKE_REQUIRED_FLAGS VOLK_FLAG_CHECK_FLAGS)
         CHECK_CXX_COMPILER_FLAG(${flag} ${have_flag})
+        unset(CMAKE_REQUIRED_FLAGS)
         if (NOT ${have_flag})
             set(have_${arch_name} FALSE)
         endif()
-- 
cgit