1 files changed, 43 insertions, 20 deletions

diff --git a/src/makefile/input.rs b/src/makefile/input.rs
index aa744c8..42187f4 100644
--- a/src/makefile/input.rs
+++ b/src/makefile/input.rs
@@ -129,9 +129,9 @@ impl<T, E: StdError + Send + Sync + 'static, I: Iterator<Item = Result<T, E>>> I
 {
 }
 
-pub struct MakefileReader<'a, R: BufRead> {
+pub struct MakefileReader<'a, 'parent, R: BufRead> {
     pub inference_rules: Vec<InferenceRule>,
-    pub macros: MacroSet<'static, 'static>,
+    pub macros: MacroSet<'parent, 'static>,
     pub targets: HashMap<String, Target>,
     pub first_non_special_target: Option<String>,
     args: &'a Args,
@@ -141,21 +141,25 @@ pub struct MakefileReader<'a, R: BufRead> {
     conditional_stack: Vec<ConditionalState>,
 }
 
-impl<'a> MakefileReader<'a, BufReader<File>> {
-    pub fn read_file(args: &'a Args, path: impl AsRef<Path>) -> Result<Self> {
+impl<'a, 'parent> MakefileReader<'a, 'parent, BufReader<File>> {
+    pub fn read_file(
+        args: &'a Args,
+        macros: MacroSet<'parent, 'static>,
+        path: impl AsRef<Path>,
+    ) -> Result<Self> {
         let file = File::open(path);
         // TODO handle errors
         let file = file.context("couldn't open makefile!")?;
         let file_reader = BufReader::new(file);
-        Self::read(args, file_reader)
+        Self::read(args, macros, file_reader)
     }
 }
 
-impl<'a, R: BufRead> MakefileReader<'a, R> {
-    pub fn read(args: &'a Args, source: R) -> Result<Self> {
+impl<'a, 'parent, R: BufRead> MakefileReader<'a, 'parent, R> {
+    pub fn read(args: &'a Args, macros: MacroSet<'parent, 'static>, source: R) -> Result<Self> {
         let mut reader = Self {
             inference_rules: Vec::new(),
-            macros: MacroSet::new(),
+            macros,
             targets: HashMap::new(),
             first_non_special_target: None,
             args,
@@ -181,10 +185,11 @@ impl<'a, R: BufRead> MakefileReader<'a, R> {
                 // POSIX says we only have to handle a single filename, but GNU make
                 // handles arbitrarily many filenames, and it's not like that's more work
                 for field in fields {
-                    self.extend(
-                        MakefileReader::read_file(self.args, field)
-                            .with_context(|| format!("while including {}", field))?,
-                    );
+                    let child_macros = self.macros.with_overlay();
+                    let child = MakefileReader::read_file(self.args, child_macros, field)
+                        .with_context(|| format!("while including {}", field))?
+                        .finish();
+                    self.extend(child);
                 }
                 continue;
             }
@@ -211,10 +216,12 @@ impl<'a, R: BufRead> MakefileReader<'a, R> {
                 {
                     let eval = self.macros.to_eval.take();
                     for eval in eval {
-                        self.extend(
-                            MakefileReader::read(self.args, Cursor::new(eval))
-                                .context("while evaling")?,
-                        );
+                        let child_macros = self.macros.with_overlay();
+                        let child =
+                            MakefileReader::read(self.args, child_macros, Cursor::new(eval))
+                                .context("while evaling")?
+                                .finish();
+                        self.extend(child);
                     }
                 }
                 let line_type = LineType::of(&line_tokens);
@@ -501,7 +508,16 @@ impl<'a, R: BufRead> MakefileReader<'a, R> {
         self.macros.expand(text)
     }
 
-    fn extend<R2: BufRead>(&mut self, new: MakefileReader<R2>) {
+    pub fn finish(self) -> FinishedMakefileReader {
+        FinishedMakefileReader {
+            inference_rules: self.inference_rules,
+            macros: self.macros.data,
+            targets: self.targets,
+            first_non_special_target: self.first_non_special_target,
+        }
+    }
+
+    fn extend(&mut self, new: FinishedMakefileReader) {
         self.inference_rules.extend(new.inference_rules);
         self.macros.extend(new.macros);
         self.targets.extend(new.targets);
@@ -511,6 +527,13 @@ impl<'a, R: BufRead> MakefileReader<'a, R> {
     }
 }
 
+pub struct FinishedMakefileReader {
+    pub inference_rules: Vec<InferenceRule>,
+    pub macros: HashMap<String, (MacroSource, TokenString)>,
+    pub targets: HashMap<String, Target>,
+    pub first_non_special_target: Option<String>,
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -530,7 +553,7 @@ worked = perhaps
 endif
         ";
         let args = Args::empty();
-        let makefile = MakefileReader::read(&args, Cursor::new(file))?;
+        let makefile = MakefileReader::read(&args, MacroSet::new(), Cursor::new(file))?;
         assert_eq!(
             makefile.expand_macros(&TokenString::r#macro("worked"))?,
             "yes"
@@ -548,7 +571,7 @@ baz
 endef
         ";
         let args = Args::empty();
-        let makefile = MakefileReader::read(&args, Cursor::new(file))?;
+        let makefile = MakefileReader::read(&args, MacroSet::new(), Cursor::new(file))?;
         assert_eq!(
             makefile.expand_macros(&TokenString::r#macro("foo"))?,
             "bar\nbaz"
@@ -593,7 +616,7 @@ clean:
         ";
 
         let args = Args::empty();
-        let makefile = MakefileReader::read(&args, Cursor::new(file))?;
+        let makefile = MakefileReader::read(&args, MacroSet::new(), Cursor::new(file))?;
         assert!(makefile.targets.contains_key("server"));
         Ok(())
     }