build system cleanup of duplicate CFLAGS entries

Add guards when adding in warnings to check for so that we don't add
duplicate entries to CFLAGS

This also deals with the warning generated with scons qt=on
about -Wmissing-prototypes not a valid C++ option

The error is that qt_env is stripping one copy of -Wmissing-prototype
and -Wstrict-prototyes from CFLAGS so that it can compile with CXX

1 files changed, 4 insertions, 2 deletions

diff --git a/SConstruct b/SConstruct
index 4eba37b3..f379e624 100644
--- a/SConstruct
+++ b/SConstruct
@@ -323,7 +323,8 @@ if 'MORECFLAGS' in os.environ:
 
 # Don't change CFLAGS if already set by environment.
 if not 'CFLAGS' in os.environ:
-    env.Append(CFLAGS=['-Wmissing-prototypes'])
+    if '-Wmissing-prototypes' not in env['CFLAGS']:
+        env.Append(CFLAGS=['-Wmissing-prototypes'])
 
 # Don't change CCFLAGS if already set by environment.
 if not 'CCFLAGS' in os.environ:
@@ -503,7 +504,8 @@ else:
     for option in ('-Wextra','-Wall', '-Wno-uninitialized','-Wno-missing-field-initializers',
                    '-Wcast-align','-Wmissing-declarations', '-Wmissing-prototypes',
                    '-Wstrict-prototypes', '-Wpointer-arith', '-Wreturn-type'):
-        config.CheckCompilerOption(option)
+        if option not in config.env['CFLAGS']:
+            config.CheckCompilerOption(option)
 
     if config.CheckCompilerOption("-pthread"):
         env.MergeFlags("-pthread")