ast: resolve simple arithmetic nodes

2 files changed, 33 insertions, 5 deletions

diff --git a/mesonbuild/ast/interpreter.py b/mesonbuild/ast/interpreter.py
index 33271b9..6db9d41 100644
--- a/mesonbuild/ast/interpreter.py
+++ b/mesonbuild/ast/interpreter.py
@@ -20,7 +20,7 @@ from .. import interpreterbase, mparser, mesonlib
 from .. import environment
 
 from ..interpreterbase import InvalidArguments, BreakRequest, ContinueRequest
-from ..mparser import BaseNode, ElementaryNode, IdNode, ArgumentNode, ArrayNode, AssignmentNode, PlusAssignmentNode, TernaryNode, EmptyNode
+from ..mparser import BaseNode, ElementaryNode, IdNode, ArgumentNode, ArrayNode, ArithmeticNode, AssignmentNode, PlusAssignmentNode, TernaryNode, EmptyNode
 
 import os, sys
 from typing import List, Any, Optional
@@ -230,18 +230,43 @@ class AstInterpreter(interpreterbase.InterpreterBase):
         self.assign_vals[node.var_name] = [self.evaluate_statement(node.value)] # Evaluate the value just in case
 
     def flatten_args(self, args: Any, include_unknown_args: bool = False) -> List[str]:
-        # Resolve ArrayNode if needed
+        def quick_resolve(n: BaseNode) -> Any:
+            if isinstance(n, IdNode):
+                if n.value not in self.assignments:
+                    return []
+                return quick_resolve(self.assignments[n.value][0])
+            elif isinstance(n, ElementaryNode):
+                return n.value
+            else:
+                return n
+
         flattend_args = []
+
         if isinstance(args, ArrayNode):
             args = [x for x in args.args.arguments]
+
         elif isinstance(args, ArgumentNode):
             args = [x for x in args.arguments]
+
+        elif isinstance(args, ArithmeticNode):
+            if args.operation != 'add':
+                return [] # Only handle string and array concats
+            l = quick_resolve(args.left)
+            r = quick_resolve(args.right)
+            if isinstance(l, str) and isinstance(r, str):
+                args = [l + r] # String concatination detected
+            else:
+                args = self.flatten_args(l) + self.flatten_args(r)
+
+        # Make sure we are always dealing with lists
         if not isinstance(args, list):
             args = [args]
+
+        # Resolve the contents of args
         for i in args:
             if isinstance(i, IdNode):
-                flattend_args += self.flatten_args(self.assignments.get(i.value, []), include_unknown_args)
-            elif isinstance(i, (ArrayNode, ArgumentNode)):
+                flattend_args += self.flatten_args(quick_resolve(i), include_unknown_args)
+            elif isinstance(i, (ArrayNode, ArgumentNode, ArithmeticNode)):
                 flattend_args += self.flatten_args(i, include_unknown_args)
             elif isinstance(i, mparser.ElementaryNode):
                 flattend_args += [i.value]
diff --git a/test cases/unit/55 introspection/meson.build b/test cases/unit/55 introspection/meson.build
index 55e80c1..5dd1b33 100644
--- a/test cases/unit/55 introspection/meson.build
+++ b/test cases/unit/55 introspection/meson.build
@@ -20,9 +20,12 @@ endif
 subdir('sharedlib')
 subdir('staticlib')
 
+var1 = '1'
+var2 = '2'
 var3 = 'test3'
 
-t1 = executable('test1', 't1.cpp', link_with: [sharedlib], install: true, build_by_default: get_option('test_opt2'))
+t1 = executable('test' + var1, ['t1.cpp'], link_with: [sharedlib], install: true, build_by_default: get_option('test_opt2'))
+#t2 = executable('test@0@'.format('' + '@0@'.format(var2)), 't2.cpp', link_with: [staticlib])
 t2 = executable('test2', 't2.cpp', link_with: [staticlib])
 t3 = executable(var3, 't3.cpp', link_with: [sharedlib, staticlib], dependencies: [dep1])