Add AstInterpreter.nesting

The AstInterpreter now stores how deep into if/elif/else we are.
This is currently dead code, but it will be read in future commits.

1 files changed, 4 insertions, 0 deletions

diff --git a/mesonbuild/ast/interpreter.py b/mesonbuild/ast/interpreter.py
index b18bb5882..f3ed7eb55 100644
--- a/mesonbuild/ast/interpreter.py
+++ b/mesonbuild/ast/interpreter.py
@@ -96,6 +96,7 @@ class AstInterpreter(InterpreterBase):
     def __init__(self, source_root: str, subdir: str, subproject: SubProject, subproject_dir: str, env: environment.Environment, visitors: T.Optional[T.List[AstVisitor]] = None):
         super().__init__(source_root, subdir, subproject, subproject_dir, env)
         self.visitors = visitors if visitors is not None else []
+        self.nesting: T.List[int] = []
         self.assignments: T.Dict[str, BaseNode] = {}
         self.assign_vals: T.Dict[str, T.Any] = {}
         self.reverse_assignment: T.Dict[str, BaseNode] = {}
@@ -283,10 +284,13 @@ class AstInterpreter(InterpreterBase):
             pass
 
     def evaluate_if(self, node: IfClauseNode) -> None:
+        self.nesting.append(0)
         for i in node.ifs:
             self.evaluate_codeblock(i.block)
+            self.nesting[-1] += 1
         if not isinstance(node.elseblock, EmptyNode):
             self.evaluate_codeblock(node.elseblock.block)
+        self.nesting.pop()
 
     def get_variable(self, varname: str) -> int:
         return 0