massively upgrade error handling

1 files changed, 25 insertions, 11 deletions

diff --git a/src/main.rs b/src/main.rs
index 1c2faf5..d560048 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,4 @@
 #![warn(
-    missing_docs,
     unreachable_pub,
     unsafe_code,
     unused_crate_dependencies,
@@ -10,17 +9,20 @@
 )]
 #![allow(clippy::redundant_pub_crate, clippy::non_ascii_literal)]
 
+use std::env::current_dir;
 use std::fs::metadata;
 use std::io::stdin;
 use std::path::PathBuf;
 
+use anyhow::bail;
+
 mod args;
 mod makefile;
 
 use args::Args;
 use makefile::Makefile;
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     let mut args = Args::from_env_and_args();
     // If no makefile is specified, try some options.
     if args.makefile.is_empty() {
@@ -29,8 +31,17 @@ fn main() {
         } else if metadata("./Makefile").is_ok() {
             "./Makefile".into()
         } else {
-            // TODO handle error gracefully
-            panic!("no makefile found");
+            bail!(
+                "no makefile specified and neither {} nor {} was found.",
+                current_dir().map_or_else(
+                    |_| "./makefile".to_string(),
+                    |path| path.join("makefile").display().to_string()
+                ),
+                current_dir().map_or_else(
+                    |_| "./Makefile".to_string(),
+                    |path| path.join("Makefile").display().to_string()
+                ),
+            );
         }];
     }
     // Read in the makefile(s) specified.
@@ -40,9 +51,9 @@ fn main() {
     let mut makefile = Makefile::new(&args);
     for filename in &args.makefile {
         if filename == &PathBuf::from("-") {
-            makefile.and_read(stdin().lock());
+            makefile.and_read(stdin().lock())?;
         } else {
-            makefile.and_read_file(filename);
+            makefile.and_read_file(filename)?;
         };
     }
 
@@ -51,15 +62,18 @@ fn main() {
     }
 
     let targets = if args.targets().count() == 0 {
-        vec![makefile
-            .first_non_special_target
-            .clone()
-            .expect("couldn't find a target!")]
+        let first_target = makefile.first_non_special_target.clone();
+        match first_target {
+            Some(x) => vec![x],
+            None => bail!("no targets given on command line or found in makefile."),
+        }
     } else {
         args.targets().cloned().collect()
     };
 
     for target in targets {
-        makefile.update_target(&target);
+        makefile.update_target(&target)?;
     }
+
+    Ok(())
 }