overhaul macro inheritance

i was really proud of the lifetimes i had going on in the previous code. i should not have been.

1 files changed, 10 insertions, 6 deletions

diff --git a/src/makefile/mod.rs b/src/makefile/mod.rs
index 9255ebf..ddfac6f 100644
--- a/src/makefile/mod.rs
+++ b/src/makefile/mod.rs
@@ -12,7 +12,9 @@ use inference_rules::InferenceRule;
 use input::FinishedMakefileReader;
 pub use input::MakefileReader;
 use lookup_internal::LookupInternal;
-use r#macro::{Macro, Set as MacroSet};
+pub use macro_scope::MacroScopeStack;
+use r#macro::Macro;
+pub use r#macro::Set as MacroSet;
 use target::{DynamicTargetSet, Target};
 use token::TokenString;
 
@@ -31,6 +33,7 @@ mod inference_rules;
 mod input;
 mod lookup_internal;
 mod r#macro;
+mod macro_scope;
 mod pattern;
 mod target;
 mod token;
@@ -51,7 +54,7 @@ pub enum ItemSource {
 pub struct Makefile<'a> {
     inference_rules: Vec<InferenceRule>,
     builtin_inference_rules: Vec<InferenceRule>,
-    pub macros: MacroSet<'static, 'static>,
+    pub macros: MacroSet,
     targets: DynamicTargetSet,
     pub first_non_special_target: Option<String>,
     args: &'a Args,
@@ -157,9 +160,9 @@ impl<'a> Makefile<'a> {
             self.update_target(&failed_include).wrap_err_with(|| {
                 format!("while building missing included file {}", &failed_include)
             })?;
-            let macros = self.macros.with_overlay();
+            let stack = MacroScopeStack::default().with_scope(&self.macros);
             let file =
-                MakefileReader::read_file(self.args, macros, failed_include, Default::default())?
+                MakefileReader::read_file(self.args, stack, failed_include, Default::default())?
                     .finish();
             self.extend(file)?;
         }
@@ -349,8 +352,9 @@ impl<'a> Makefile<'a> {
     }
 
     fn expand_macros(&self, text: &TokenString, target: Option<&Target>) -> Result<String> {
-        self.macros
-            .with_lookup(LookupInternal::new(target, &|name| self.get_target(name)))
+        MacroScopeStack::default()
+            .with_scope(&self.macros)
+            .with_scope(&LookupInternal::new(target, &|name| self.get_target(name)))
             .expand(
                 text,
                 #[cfg(feature = "full")]