Add new array type option

This exposes the already existing UserStringArrayOption class through
the meson_options.txt. The intention is to provide a way for projects to
take list/array type arguments and validate that all of the elements in
that array are valid without using complex looping constructrs.

11 files changed, 208 insertions, 19 deletions

diff --git a/docs/markdown/Build-options.md b/docs/markdown/Build-options.md
index cb7b19e..f05eb7b 100644
--- a/docs/markdown/Build-options.md
+++ b/docs/markdown/Build-options.md
@@ -16,18 +16,37 @@ Here is a simple option file.
 option('someoption', type : 'string', value : 'optval', description : 'An option')
 option('other_one', type : 'boolean', value : false)
 option('combo_opt', type : 'combo', choices : ['one', 'two', 'three'], value : 'three')
+option('array_opt', type : 'array', choices : ['one', 'two', 'three'], value : ['one', 'two'])
 ```
 
-This demonstrates the three basic option types and their usage. String
-option is just a free form string and a boolean option is,
-unsurprisingly, true or false. The combo option can have any value
-from the strings listed in argument `choices`. If `value` is not set,
-it defaults to empty string for strings, `true` for booleans or the
-first element in a combo. You can specify `description`, which is a
-free form piece of text describing the option. It defaults to option
-name.
+All types allow a `description` value to be set describing the option, if no
+option is set then the name of the option will be used instead.
 
-These options are accessed in Meson code with the `get_option` function.
+### Strings
+
+The string type is a free form string. If the default value is not set then an
+empty string will be used as the default.
+
+### Booleans
+
+Booleans may have values of either `true` or `false`. If not default value is
+supplied then `true` will be used as the default.
+
+### Combos
+
+A combo allows any one of the values in the `choices` parameter to be selected.
+If no default value is set then the first value will be the default.
+
+### Arrays
+
+Arrays allow one or more of the values in the `choices` parameter to be selected.
+If the `value` parameter is unset then the values of `choices` will be used as
+the default.
+
+This type is new in version 0.44.0
+
+
+## Using build options
 
 ```meson
 optval = get_option('opt_name')
diff --git a/docs/markdown/snippets/option-array-type.md b/docs/markdown/snippets/option-array-type.md
new file mode 100644
index 0000000..f073dc1
--- /dev/null
+++ b/docs/markdown/snippets/option-array-type.md
@@ -0,0 +1,17 @@
+# An array type for user options
+
+Previously to have an option that took more than one value a string value would
+have to be created and split, but validating this was difficult. A new array type
+has been added to the meson_options.txt for this case. It works like a 'combo', but
+allows more than one option to be passed. When used on the command line (with -D),
+values are passed as a comma separated list.
+
+```meson
+option('array_opt', type : 'array', choices : ['one', 'two', 'three'], value : ['one'])
+```
+
+These can be overwritten on the command line,
+
+```meson
+meson _build -Darray_opt=two,three
+```
diff --git a/mesonbuild/coredata.py b/mesonbuild/coredata.py
index 401211a..af5a19a 100644
--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -127,24 +127,37 @@ class UserComboOption(UserOption):
 class UserStringArrayOption(UserOption):
     def __init__(self, name, description, value, **kwargs):
         super().__init__(name, description, kwargs.get('choices', []))
-        self.set_value(value)
-
-    def validate(self, value):
-        if isinstance(value, str):
-            if not value.startswith('['):
-                raise MesonException('Valuestring does not define an array: ' + value)
-            newvalue = ast.literal_eval(value)
+        self.set_value(value, user_input=False)
+
+    def validate(self, value, user_input):
+        # User input is for options defined on the command line (via -D
+        # options). Users should put their input in as a comma separated
+        # string, but for defining options in meson_options.txt the format
+        # should match that of a combo
+        if not user_input:
+            if isinstance(value, str):
+                if not value.startswith('['):
+                    raise MesonException('Valuestring does not define an array: ' + value)
+                newvalue = ast.literal_eval(value)
+            else:
+                newvalue = value
         else:
-            newvalue = value
+            assert isinstance(value, str)
+            newvalue = [v.strip() for v in value.split(',')]
         if not isinstance(newvalue, list):
             raise MesonException('"{0}" should be a string array, but it is not'.format(str(newvalue)))
         for i in newvalue:
             if not isinstance(i, str):
                 raise MesonException('String array element "{0}" is not a string.'.format(str(newvalue)))
+        if self.choices:
+            bad = [x for x in newvalue if x not in self.choices]
+            if bad:
+                raise MesonException('Options "{}" are not in allowed choices: "{}"'.format(
+                    ', '.join(bad), ', '.join(self.choices)))
         return newvalue
 
-    def set_value(self, newvalue):
-        self.value = self.validate(newvalue)
+    def set_value(self, newvalue, user_input=True):
+        self.value = self.validate(newvalue, user_input)
 
     def validate_value(self, value):
         self.validate(value)
diff --git a/mesonbuild/optinterpreter.py b/mesonbuild/optinterpreter.py
index 01dd036..22a263e 100644
--- a/mesonbuild/optinterpreter.py
+++ b/mesonbuild/optinterpreter.py
@@ -84,9 +84,25 @@ def ComboParser(name, description, kwargs):
             raise OptionException('Combo choice elements must be strings.')
     return coredata.UserComboOption(name, description, choices, kwargs.get('value', choices[0]))
 
+@permitted_kwargs({'value', 'choices'})
+def string_array_parser(name, description, kwargs):
+    if 'choices' not in kwargs:
+        raise OptionException('Array option missing "choices" keyword.')
+    choices = kwargs['choices']
+    if not isinstance(choices, list):
+        raise OptionException('Array choices must be an array.')
+    for i in choices:
+        if not isinstance(i, str):
+            raise OptionException('Array choice elements must be strings.')
+    value = kwargs.get('value', choices)
+    if not isinstance(value, list):
+        raise OptionException('Array choices must be passed as an array.')
+    return coredata.UserStringArrayOption(name, description, value, choices=choices)
+
 option_types = {'string': StringParser,
                 'boolean': BooleanParser,
                 'combo': ComboParser,
+                'array': string_array_parser,
                 }
 
 class OptionInterpreter:
diff --git a/run_unittests.py b/run_unittests.py
index 91a71ce..42f4e19 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -1562,6 +1562,53 @@ int main(int argc, char **argv) {
         cargs = ['-I' + incdir.as_posix()]
         self.assertEqual(foo_dep.get_compile_args(), cargs)
 
+    def test_array_option_change(self):
+        def get_opt():
+            opts = self.introspect('--buildoptions')
+            for x in opts:
+                if x.get('name') == 'list':
+                    return x
+            raise Exception(opts)
+
+        expected = {
+            'name': 'list',
+            'description': 'list',
+            'type': 'stringarray',
+            'value': ['foo', 'bar'],
+        }
+        tdir = os.path.join(self.unit_test_dir, '18 array option')
+        self.init(tdir)
+        original = get_opt()
+        self.assertDictEqual(original, expected)
+
+        expected['value'] = ['oink', 'boink']
+        self.setconf('-Dlist=oink,boink')
+        changed = get_opt()
+        self.assertEqual(changed, expected)
+
+    def test_array_option_bad_change(self):
+        def get_opt():
+            opts = self.introspect('--buildoptions')
+            for x in opts:
+                if x.get('name') == 'list':
+                    return x
+            raise Exception(opts)
+
+        expected = {
+            'name': 'list',
+            'description': 'list',
+            'type': 'stringarray',
+            'value': ['foo', 'bar'],
+        }
+        tdir = os.path.join(self.unit_test_dir, '18 array option')
+        self.init(tdir)
+        original = get_opt()
+        self.assertDictEqual(original, expected)
+        with self.assertRaises(subprocess.CalledProcessError):
+            self.setconf('-Dlist=bad')
+        changed = get_opt()
+        self.assertDictEqual(changed, expected)
+
 
 class FailureTests(BasePlatformTests):
     '''
diff --git a/test cases/common/166 array option/meson.build b/test cases/common/166 array option/meson.build
new file mode 100644
index 0000000..bfcde7c
--- /dev/null
+++ b/test cases/common/166 array option/meson.build
@@ -0,0 +1,17 @@
+# Copyright © 2017 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+project('stringarray default options')
+
+assert(get_option('array') == ['foo', 'bar'], 'Default value for array is not equal to choices')
diff --git a/test cases/common/166 array option/meson_options.txt b/test cases/common/166 array option/meson_options.txt
new file mode 100644
index 0000000..7ed0ac1
--- /dev/null
+++ b/test cases/common/166 array option/meson_options.txt
@@ -0,0 +1,19 @@
+# Copyright © 2017 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+option(
+  'array',
+  type : 'array',
+  choices : ['foo', 'bar'],
+)
diff --git a/test cases/common/47 options/meson.build b/test cases/common/47 options/meson.build
index 2a764f0..863703c 100644
--- a/test cases/common/47 options/meson.build
+++ b/test cases/common/47 options/meson.build
@@ -12,6 +12,11 @@ if get_option('combo_opt') != 'combo'
   error('Incorrect value to combo option.')
 endif
 
+if get_option('array_opt') != ['one', 'two']
+  message(get_option('array_opt'))
+  error('Incorrect value for array option')
+endif
+
 # If the default changes, update test cases/unit/13 reconfigure
 if get_option('b_lto') != false
   error('Incorrect value in base option.')
diff --git a/test cases/common/47 options/meson_options.txt b/test cases/common/47 options/meson_options.txt
index 653dd75..8978d44 100644
--- a/test cases/common/47 options/meson_options.txt
+++ b/test cases/common/47 options/meson_options.txt
@@ -1,3 +1,4 @@
 option('testoption', type : 'string', value : 'optval', description : 'An option to do something')
 option('other_one', type : 'boolean', value : false)
 option('combo_opt', type : 'combo', choices : ['one', 'two', 'combo'], value : 'combo')
+option('array_opt', type : 'array', choices : ['one', 'two', 'three'], value : ['one', 'two'])
diff --git a/test cases/unit/18 array option/meson.build b/test cases/unit/18 array option/meson.build
new file mode 100644
index 0000000..2b44181
--- /dev/null
+++ b/test cases/unit/18 array option/meson.build
@@ -0,0 +1,15 @@
+# Copyright © 2017 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+project('array option test')
diff --git a/test cases/unit/18 array option/meson_options.txt b/test cases/unit/18 array option/meson_options.txt
new file mode 100644
index 0000000..0ccdcc4
--- /dev/null
+++ b/test cases/unit/18 array option/meson_options.txt
@@ -0,0 +1,20 @@
+# Copyright © 2017 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+option(
+  'list',
+  type : 'array',
+  value : ['foo', 'bar'],
+  choices : ['foo', 'bar', 'oink', 'boink'],
+)