Allow optional collection of code coverage information with gcc

.gitignore

@@ -25,3 +25,5 @@ config.log
 .pydevproject
 .settings
 Cantera/matlab/build_cantera.m
+*.gcda
+*.gcno

SConstruct

@@ -222,6 +222,11 @@ opts.AddVariables(
         'debug',
         """Enable extra printing code to aid in debugging.""",
         False),
+    BoolVariable(
+        'coverage',
+        """Enable collection of code coverage information with gcov.
+           Available only when compiling with gcc.""",
+        False),
     BoolVariable(
         'with_lattice_solid',
         """Include thermodynamic model for lattice solids in the
@@ -709,6 +714,16 @@ else:
     env['CCFLAGS'] = listify(env['cc_flags']) + listify(env['debug_flags'])
     env['LINKFLAGS'] += listify(defaults.debugLinkFlags)
 
+if env['coverage']:
+    if  env['CC'] == 'gcc':
+        env.Append(CCFLAGS=['-fprofile-arcs', '-ftest-coverage'])
+        env.Append(LINKFLAGS=['-fprofile-arcs', '-ftest-coverage'])
+#        ipdb()
+
+    else:
+        print 'Error: coverage testing is only available with GCC'
+        exit(0)
+
 # **************************************
 # *** Set options needed in config.h ***
 # **************************************