From 6626a20ea9dde169ca75a4e4c83b5fb5b85c1e47 Mon Sep 17 00:00:00 2001
From: Melody Horn <melody@boringcactus.com>
Date: Fri, 26 Mar 2021 20:43:41 -0600
Subject: don't borrow targets mutably for the whole get_target process

---
 src/makefile/mod.rs | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/makefile/mod.rs b/src/makefile/mod.rs
index 2959953..f38815d 100644
--- a/src/makefile/mod.rs
+++ b/src/makefile/mod.rs
@@ -533,7 +533,8 @@ impl Makefile {
             _ => vec![]
         };
 
-        let mut targets = self.targets.borrow_mut();
+        let targets = self.targets.borrow();
+        let mut new_target = None;
         let exists_but_infer_anyway = if follow_gnu {
             match targets.get(name) {
                 Some(target) => {
@@ -567,13 +568,12 @@ impl Makefile {
                         };
                         for prereq in prereq_path_options {
                             if prereq.exists() {
-                                let new_target = Target {
+                                new_target = Some(Target {
                                     name: name.into(),
                                     prerequisites: vec![prereq.to_string_lossy().into()],
                                     commands: rule.commands.clone(),
                                     already_updated: Cell::new(false),
-                                };
-                                targets.insert(name.into(), Rc::new(RefCell::new(new_target)));
+                                });
                                 break 'rules;
                             }
                         }
@@ -582,36 +582,38 @@ impl Makefile {
             }
         }
 
-        if !targets.contains_key(name) {
+        if !targets.contains_key(name) && new_target.is_none() {
             // well, inference didn't work. is there a default?
             if let Some(default) = targets.get(".DEFAULT") {
                 let default = default.borrow();
                 let commands = default.commands.clone();
                 drop(default);
-                let new_target = Target {
+                new_target = Some(Target {
                     name: name.into(),
                     prerequisites: vec![],
                     commands,
                     already_updated: Cell::new(false),
-                };
-                targets.insert(name.into(), Rc::new(RefCell::new(new_target)));
+                });
             } else {
                 // if it already exists, it counts as up-to-date
                 if Path::new(name).exists() {
-                    let new_target = Target {
+                    new_target = Some(Target {
                         name: name.into(),
                         prerequisites: vec![],
                         commands: vec![],
                         already_updated: Cell::new(true),
-                    };
-                    targets.insert(name.into(), Rc::new(RefCell::new(new_target)));
+                    });
                 }
             }
         }
 
         drop(targets);
-        let targets = self.targets.borrow();
+        if let Some(new_target) = new_target {
+            let mut targets = self.targets.borrow_mut();
+            targets.insert(new_target.name.clone(), Rc::new(RefCell::new(new_target)));
+        }
 
+        let targets = self.targets.borrow();
         targets.get(name).expect("Target not found!").clone()
     }
 
-- 
cgit v1.2.3