From 7f610533718876ea9d7d63d50c65b6aff4bb16b2 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      | 4 +++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ebb29cda0..f892848b7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,14 @@ enable_testing()
 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 82824a0ee..d0a98b605 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,7 +9,9 @@ Security
      2048 bits. This can be changed with ssl_set_dh_params().
 
 Bugfix
-   * Fix thread-safety issue in the SSL debug module.
+   * Fix thread-safety issue in SSL debug module (found by Edwin van Vliet).
+   * Fix build error with CMake and pre-4.5 versions of GCC (found by Hugo
+     Leisink).
 
 Changes
    * Add SSL_MIN_DHM_BYTES configuration parameter in config.h to choose the