Add option to compile yaml-cpp or use system library

SConstruct

@@ -440,6 +440,14 @@ config_options = [
            ('y'), from a Git submodule ('n'), or to decide automatically
            ('default').""",
         'default', ('default', 'y', 'n')),
+    EnumVariable(
+        'system_yamlcpp',
+        """Select whether to use the yaml-cpp library from a system installation
+           ('y'), from a Git submodule ('n'), or to decide automatically
+           ('default'). If yaml-cpp is not installed directly into system
+           include and library directories, then you will need to add those
+           directories to 'extra_inc_dirs' and 'extra_lib_dirs'.""",
+        'default', ('default', 'y', 'n')),
     EnumVariable(
         'system_sundials',
         """Select whether to use SUNDIALS from a system installation ('y'), from
@@ -908,6 +916,33 @@ elif env['system_googletest'] == 'y':
 elif env['system_googletest'] == 'n':
     env['googletest'] = 'submodule'
 
+# Check for yaml-cpp library and checkout submodule if needed
+if env['system_yamlcpp'] in ('y', 'default'):
+    if conf.CheckCXXHeader('yaml-cpp/yaml.h', '""'):
+        env['system_yamlcpp'] = True
+        print("""INFO: Using system installation of yaml-cpp library.""")
+
+    elif env['system_yamlcpp'] == 'y':
+        config_error('Expected system installation of yaml-cpp library, but it '
+            'could not be found.')
+
+if env['system_yamlcpp'] in ('n', 'default'):
+    env['system_yamlcpp'] = False
+    print("""INFO: Using private installation of yaml-cpp library.""")
+    if not os.path.exists('ext/yaml-cpp/include/yaml-cpp/yaml.h'):
+        if not os.path.exists('.git'):
+            config_error('yaml-cpp is missing. Install source in ext/yaml-cpp.')
+
+        try:
+            code = subprocess.call(['git', 'submodule', 'update', '--init',
+                                    '--recursive', 'ext/yaml-cpp'])
+        except Exception:
+            code = -1
+        if code:
+            config_error('yaml-cpp submodule checkout failed.\n'
+                         'Try manually checking out the submodule with:\n\n'
+                         '    git submodule update --init --recursive ext/yaml-cpp\n')
+
 # Check for googletest and checkout submodule if needed
 if env['googletest'] in ('system', 'default'):
     has_gtest = conf.CheckCXXHeader('gtest/gtest.h', '""')
@@ -1444,6 +1479,7 @@ cdefine('LAPACK_NAMES_LOWERCASE', 'lapack_names', 'lower')
 cdefine('CT_USE_LAPACK', 'use_lapack')
 cdefine('CT_USE_SYSTEM_EIGEN', 'system_eigen')
 cdefine('CT_USE_SYSTEM_FMT', 'system_fmt')
+cdefine('CT_USE_SYSTEM_YAMLCPP', 'system_yamlcpp')
 
 config_h_build = env.Command('build/src/config.h.build',
                              'include/cantera/base/config.h.in',

ext/SConscript

@@ -82,6 +82,24 @@ if env['system_sundials'] == 'n':
         libraryTargets.extend(localenv.SharedObject(
             [f for f in mglob(localenv, 'sundials/src/'+subdir, 'c')]))
 
+if not env['system_yamlcpp']:
+    localenv = prep_default(env)
+    localenv.Prepend(CPPPATH=Dir('#include/cantera/ext'))
+    license_files.append(('YAML-CPP', 'yaml-cpp/LICENSE'))
+
+    # Copy header files into common include directory
+    for subdir in ('', 'contrib', 'node', 'node/detail'):
+        for header in mglob(env, 'yaml-cpp/include/yaml-cpp/'+subdir, 'h'):
+            h = build(localenv.Command('#include/cantera/ext/yaml-cpp/{}/{}'.format(subdir, header.name),
+                                       '#ext/yaml-cpp/include/yaml-cpp/{}/{}'.format(subdir, header.name),
+                                       Copy('$TARGET', '$SOURCE')))
+
+    # Compile yaml-cpp source files
+    for subdir in ('', 'contrib'):
+        libraryTargets.extend(localenv.SharedObject(
+            [f for f in mglob(localenv, 'yaml-cpp/src/'+subdir, 'cpp')]))
+
+
 if not env['system_eigen']:
     license_files.append(('Eigen', 'eigen/COPYING.MPL2'))
     h = build(copyenv.Command('#include/cantera/ext/Eigen', '#ext/eigen/Eigen',

include/cantera/base/config.h.in

@@ -44,6 +44,7 @@ typedef int ftnlen;       // Fortran hidden string length type
 
 %(CT_USE_SYSTEM_EIGEN)s
 %(CT_USE_SYSTEM_FMT)s
+%(CT_USE_SYSTEM_YAMLCPP)s
 
 //--------- operating system --------------------------------------
 

include/cantera/base/yaml.h

@@ -0,0 +1,6 @@
+#include "cantera/base/ct_defs.h"
+#if CT_USE_SYSTEM_YAMLCPP
+#include "yaml-cpp/yaml.h"
+#else
+#include "cantera/ext/yaml-cpp/yaml.h"
+#endif

src/kinetics/importKinetics.cpp

@@ -18,6 +18,7 @@
 #include "cantera/kinetics/Reaction.h"
 #include "cantera/base/stringUtils.h"
 #include "cantera/base/ctml.h"
+#include "cantera/base/yaml.h"
 
 #include <cstring>