Interpreter: Add "in" and "not in" operators

Closes: #3600

4 files changed, 43 insertions, 11 deletions

diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index c05b92a..2e4faa1 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -29,6 +29,7 @@ from .interpreterbase import check_stringlist, flatten, noPosargs, noKwargs, str
 from .interpreterbase import InterpreterException, InvalidArguments, InvalidCode, SubdirDoneRequest
 from .interpreterbase import InterpreterObject, MutableInterpreterObject, Disabler
 from .interpreterbase import FeatureNew, FeatureDeprecated, FeatureNewKwargs
+from .interpreterbase import ObjectHolder
 from .modules import ModuleReturnValue
 
 import os, shutil, uuid
@@ -57,14 +58,6 @@ def stringifyUserArguments(args):
     raise InvalidArguments('Function accepts only strings, integers, lists and lists thereof.')
 
 
-class ObjectHolder:
-    def __init__(self, obj, subproject=None):
-        self.held_object = obj
-        self.subproject = subproject
-
-    def __repr__(self):
-        return '<Holder: {!r}>'.format(self.held_object)
-
 class FeatureOptionHolder(InterpreterObject, ObjectHolder):
     def __init__(self, env, option):
         InterpreterObject.__init__(self)
diff --git a/mesonbuild/interpreterbase.py b/mesonbuild/interpreterbase.py
index 1c74eeb..22bb95b 100644
--- a/mesonbuild/interpreterbase.py
+++ b/mesonbuild/interpreterbase.py
@@ -21,6 +21,14 @@ from . import environment, dependencies
 import os, copy, re, types
 from functools import wraps
 
+class ObjectHolder:
+    def __init__(self, obj, subproject=None):
+        self.held_object = obj
+        self.subproject = subproject
+
+    def __repr__(self):
+        return '<Holder: {!r}>'.format(self.held_object)
+
 # Decorators for method calls.
 
 def check_stringlist(a, msg='Arguments must be strings.'):
@@ -487,6 +495,13 @@ class InterpreterBase:
             return False
         return True
 
+    def evaluate_in(self, val1, val2):
+        if not isinstance(val1, (str, int, float, ObjectHolder)):
+            raise InvalidArguments('lvalue of "in" operator must be a string, integer, float, or object')
+        if not isinstance(val2, (list, dict)):
+            raise InvalidArguments('rvalue of "in" operator must be an array or a dict')
+        return val1 in val2
+
     def evaluate_comparison(self, node):
         val1 = self.evaluate_statement(node.left)
         if is_disabler(val1):
@@ -494,6 +509,10 @@ class InterpreterBase:
         val2 = self.evaluate_statement(node.right)
         if is_disabler(val2):
             return val2
+        if node.ctype == 'in':
+            return self.evaluate_in(val1, val2)
+        elif node.ctype == 'notin':
+            return not self.evaluate_in(val1, val2)
         valid = self.validate_comparison_types(val1, val2)
         # Ordering comparisons of different types isn't allowed since PR #1810
         # (0.41.0).  Since PR #2884 we also warn about equality comparisons of
diff --git a/mesonbuild/mparser.py b/mesonbuild/mparser.py
index 9af6dac..429f014 100644
--- a/mesonbuild/mparser.py
+++ b/mesonbuild/mparser.py
@@ -90,8 +90,9 @@ class Lexer:
     def __init__(self, code):
         self.code = code
         self.keywords = {'true', 'false', 'if', 'else', 'elif',
-                         'endif', 'and', 'or', 'not', 'foreach', 'endforeach'}
-        self.future_keywords = {'continue', 'break', 'in', 'return'}
+                         'endif', 'and', 'or', 'not', 'foreach', 'endforeach',
+                         'in'}
+        self.future_keywords = {'continue', 'break', 'return'}
         self.token_specification = [
             # Need to be sorted longest to shortest.
             ('ignore', re.compile(r'[ \t]')),
@@ -436,7 +437,9 @@ comparison_map = {'equal': '==',
                   'lt': '<',
                   'le': '<=',
                   'gt': '>',
-                  'ge': '>='
+                  'ge': '>=',
+                  'in': 'in',
+                  'notin': 'not in',
                   }
 
 # Recursive descent parser for Meson's definition language.
@@ -543,6 +546,8 @@ class Parser:
         for nodename, operator_type in comparison_map.items():
             if self.accept(nodename):
                 return ComparisonNode(operator_type, left, self.e5())
+        if self.accept('not') and self.accept('in'):
+            return ComparisonNode('notin', left, self.e5())
         return left
 
     def e5(self):
diff --git a/test cases/common/17 comparison/meson.build b/test cases/common/17 comparison/meson.build
index fb641ed..bba0168 100644
--- a/test cases/common/17 comparison/meson.build
+++ b/test cases/common/17 comparison/meson.build
@@ -137,3 +137,18 @@ assert(2 != 'st', 'not equal')
 assert(not ([] == 'st'), 'not equal')
 assert(not ([] == 1), 'not equal')
 assert(not (2 == 'st'), 'not equal')
+
+# "in" and "not in" operators
+
+assert(1 in [1, 2], '''1 should be in [1, 2]''')
+assert(3 not in [1, 2], '''3 shouldn't be in [1, 2]''')
+assert(not (3 in [1, 2]), '''3 shouldn't be in [1, 2]''')
+
+assert('b' in ['a', 'b'], ''''b' should be in ['a', 'b']''')
+assert('c' not in ['a', 'b'], ''''c' shouldn't be in ['a', 'b']''')
+
+assert(exe1 in [exe1, exe2], ''''exe1 should be in [exe1, exe2]''')
+assert(exe3 not in [exe1, exe2], ''''exe3 shouldn't be in [exe1, exe2]''')
+
+assert('a' in {'a': 'b'}, '''1 should be in {'a': 'b'}''')
+assert('b' not in {'a': 'b'}, '''1 should be in {'a': 'b'}''')