Use track_caller to make debugging bindgen build script errors ea…

…sier (#3383)

crates/libs/bindgen/src/io.rs

@@ -1,20 +1,34 @@
 use std::io::BufRead;
 
+#[track_caller]
 pub fn read_file_lines(path: &str) -> Vec<String> {
-    let file = std::io::BufReader::new(
-        std::fs::File::open(path).unwrap_or_else(|_| panic!("failed to open file `{path}`")),
-    );
+    let Ok(file) = std::fs::File::open(path) else {
+        panic!("failed to open file `{path}`")
+    };
 
-    file.lines()
-        .map(|line| line.unwrap_or_else(|_| panic!("failed to read file lines `{path}`")))
-        .collect()
+    let file = std::io::BufReader::new(file);
+    let mut lines = vec![];
+
+    for line in file.lines() {
+        let Ok(line) = line else {
+            panic!("failed to read file lines `{path}`");
+        };
+
+        lines.push(line);
+    }
+
+    lines
 }
 
+#[track_caller]
 pub fn write_to_file<C: AsRef<[u8]>>(path: &str, contents: C) {
     if let Some(parent) = std::path::Path::new(path).parent() {
-        std::fs::create_dir_all(parent)
-            .unwrap_or_else(|_| panic!("failed to create directory `{path}`"));
+        if std::fs::create_dir_all(parent).is_err() {
+            panic!("failed to create directory `{path}`");
+        }
     }
 
-    std::fs::write(path, contents).unwrap_or_else(|_| panic!("failed to write file `{path}`"));
+    if std::fs::write(path, contents).is_err() {
+        panic!("failed to write file `{path}`");
+    }
 }

crates/libs/bindgen/src/lib.rs

@@ -201,16 +201,19 @@ enum ArgKind {
     Derive,
 }
 
+#[track_caller]
 fn expand_args<I, S>(args: I) -> Vec<String>
 where
     I: IntoIterator<Item = S>,
     S: AsRef<str>,
 {
     // This function is needed to avoid a recursion limit in the Rust compiler.
+    #[track_caller]
     fn from_string(result: &mut Vec<String>, value: &str) {
         expand_args(result, value.split_whitespace().map(|arg| arg.to_string()))
     }
 
+    #[track_caller]
     fn expand_args<I, S>(result: &mut Vec<String>, args: I)
     where
         I: IntoIterator<Item = S>,
@@ -241,7 +244,9 @@ where
     result
 }
 
+#[track_caller]
 fn expand_input(input: &[&str]) -> Vec<File> {
+    #[track_caller]
     fn expand_input(result: &mut Vec<String>, input: &str) {
         let path = std::path::Path::new(input);
 
@@ -295,12 +300,17 @@ fn expand_input(input: &[&str]) -> Vec<File> {
         .collect();
     }
 
-    input.extend(paths.iter().map(|path| {
-        let bytes =
-            std::fs::read(path).unwrap_or_else(|_| panic!("failed to read binary file `{path}`"));
+    for path in &paths {
+        let Ok(bytes) = std::fs::read(path) else {
+            panic!("failed to read binary file `{path}`");
+        };
 
-        File::new(bytes).unwrap_or_else(|| panic!("failed to read .winmd format `{path}`"))
-    }));
+        let Some(file) = File::new(bytes) else {
+            panic!("failed to read .winmd format `{path}`");
+        };
+
+        input.push(file);
+    }
 
     input
 }

crates/libs/bindgen/src/writer/mod.rs

@@ -20,6 +20,7 @@ impl Writer {
         clone
     }
 
+    #[track_caller]
     pub fn write(&self, tree: TypeTree) {
         if self.config.package {
             self.write_package(&tree);
@@ -28,6 +29,7 @@ impl Writer {
         }
     }
 
+    #[track_caller]
     fn write_file(&self, tree: TypeTree) {
         let tokens = if self.config.flat {
             self.write_flat(tree)