Scons checking for compiler option - scons

Question

I want to check in Scons that my compiler support some option (for example
-fcilkplus). The only way I manage to do it is the following sequence of
operations:
env.Prepend(CXXFLAGS = ['-fcilkplus'], LIBS = ['cilkrts'])
Then I launch my custom checker:
def CheckCilkPlusCompiler(context):
test = """
#include <cilk/cilk.h>
#include <assert.h>
int fib(int n) {
if (n < 2) return n;
int a = cilk_spawn fib(n-1);
int b = fib(n-2);
cilk_sync;
return a + b;
}
int main() {
int result = fib(30);
assert(result == 832040);
return 0;
}
"""
context.Message('Checking Cilk++ compiler ... ')
result = context.TryRun(test, '.cpp')
context.Result(result[0])
return result[0]
Now if it fails, I have to remove the two options extra flags -fcilkplus
cilkrts from the environment variables. Is there a better way to do that ?
The problem is that I can't manage to access to the env from the context and
therefore I can't make a clone of it.

Answer 1

You can use check the availability of a library with SCons as follows:
env = Environment()
conf = Configure(env)
if not conf.CheckLib('cilkrts'):
print 'Did not find libcilkrts.a, exiting!'
Exit(1)
else:
env.Prepend(CXXFLAGS = ['-fcilkplus'], LIBS = ['cilkrts'])
env = conf.Finish()
You could also check the availability of a header as follows:
env = Environment()
conf = Configure(env)
if conf.CheckCHeader('cilk/cilk.h'):
env.Prepend(CXXFLAGS = ['-fcilkplus'], LIBS = ['cilkrts'])
env = conf.Finish()
Update:
I just realized, you can access the environment on the Configure object as follows:
conf.env.Append(...)