Merge pull request #15 from cyqsimon/ban-abs

Explicitly disallow absolute paths

codegen/src/lib.rs

@@ -30,7 +30,8 @@ use syn::{Error, LitByteStr, LitStr, Result};
 /// `deflate_file!("file")` is equivalent to `include_bytes!("file.gz")`.
 ///
 /// # Parameters
-/// This macro accepts exactly one literal parameter that refers to a path, either absolute or relative to `CARGO_MANIFEST_DIR`.
+/// This macro accepts exactly one literal parameter that refers to a path relative to
+/// `CARGO_MANIFEST_DIR`. Absolute paths are not supported.
 ///
 /// Note that **this is distinct from the behaviour of the builtin `include_bytes!`/`include_str!` macros** —
 /// `includle_bytes!`/`include_str!` paths are relative to the current source file, while `deflate_file!` paths are relative to
@@ -66,21 +67,21 @@ pub fn deflate_utf8_file(ts: TokenStream) -> TokenStream {
 }
 
 fn inner(ts: TokenStream, utf8: bool) -> Result<impl Into<TokenStream>> {
+    fn emap<E: std::fmt::Display>(error: E) -> Error {
+        Error::new(Span::call_site(), error)
+    }
+
     let dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
 
     let lit = syn::parse::<LitStr>(ts)?;
     let path = PathBuf::from(lit.value());
 
-    let target = if path.is_relative() {
-        dir.join(path)
-    } else {
-        path
-    };
-
-    fn emap<E: std::fmt::Display>(error: E) -> Error {
-        Error::new(Span::call_site(), error)
+    if path.is_absolute() {
+        Err(emap("absolute paths are not supported"))?;
     }
 
+    let target = dir.join(path);
+
     let mut file = File::open(target).map_err(emap)?;
 
     let mut encoder = Encoder::new(Vec::<u8>::new());

src/lib.rs

@@ -49,10 +49,10 @@ pub use lazy_static::lazy_static;
 /// - `$name` is the name of the static variable..
 /// - `$type` can be either `[u8]` or `str`. However, the actual type created would dereference
 /// into `Vec<u8>` and `String` (although they are `AsRef<[u8]>` and `AsRef<str>`) respectively.
-/// - `$file` is either an absolute path or a path relative to the current
-/// [`CARGO_MANIFEST_DIR`][4]. Note that **this is distinct from the behaviour of the builtin
-/// `include_bytes!`/`include_str!` macros** &mdash; `includle_bytes!`/`include_str!` paths are
-/// relative to the current source file, while `flate!` paths are relative to `CARGO_MANIFEST_DIR`.
+/// - `$file` is a path relative to the current [`CARGO_MANIFEST_DIR`][4]. Absolute paths are not supported.
+/// Note that **this is distinct from the behaviour of the builtin `include_bytes!`/`include_str!`
+/// macros** &mdash; `includle_bytes!`/`include_str!` paths are relative to the current source file,
+/// while `flate!` paths are relative to `CARGO_MANIFEST_DIR`.
 ///
 /// # Returns
 /// The macro expands to a [`lazy_static`][3] call, which lazily inflates the compressed bytes.