From bcb0460224ee4651fa5ecf77b2c3a784e10616c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg@elzevir.fr>
Date: Sun, 19 Jul 2015 16:00:04 +0200
Subject: [PATCH] Fix bug with cmake and old version of GCC

---
 CMakeLists.txt | 9 ++++++++-
 ChangeLog      | 2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1f556f39d..607b2c4c8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,14 @@ set(CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE}
 string(REGEX MATCH "Clang" CMAKE_COMPILER_IS_CLANG "${CMAKE_C_COMPILER_ID}")
 
 if(CMAKE_COMPILER_IS_GNUCC)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings -Wlogical-op")
+    # some warnings we want are not available with old GCC versions
+    # note: starting with CMake 2.8 we could use CMAKE_C_COMPILER_VERSION
+    execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion
+                    OUTPUT_VARIABLE GCC_VERSION)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings")
+    if (GCC_VERSION VERSION_GREATER 4.5 OR GCC_VERSION VERSION_EQUAL 4.5)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wlogical-op")
+    endif()
     set(CMAKE_C_FLAGS_RELEASE     "-O2")
     set(CMAKE_C_FLAGS_DEBUG       "-O0 -g3")
     set(CMAKE_C_FLAGS_COVERAGE    "-O0 -g3 --coverage")
diff --git a/ChangeLog b/ChangeLog
index 0d2e2a12b..77a5b9da7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,8 @@ mbed TLS ChangeLog (Sorted per branch, date)
 
 Bugfix
    * Fix segfault in the benchmark program when benchmarking DHM.
+   * Fix build error with CMake and pre-4.5 versions of GCC (found by Hugo
+     Leisink).
 
 = mbed TLS 2.0.0 released 2015-07-13