Merge pull request #546 from Kijewski/pr-relative-path

derive: track included files with relative path

askama_derive/src/generator.rs

@@ -5,8 +5,9 @@ mod node;
 
 use std::borrow::Cow;
 use std::collections::hash_map::HashMap;
+use std::env::current_dir;
 use std::ops::Deref;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::str;
 use std::sync::Arc;
 
@@ -17,6 +18,7 @@ use parser::{
 use rustc_hash::FxBuildHasher;
 
 use crate::ascii_str::{AsciiChar, AsciiStr};
+use crate::generator::helpers::{clean_path, diff_paths};
 use crate::heritage::{Context, Heritage};
 use crate::html::write_escaped_str;
 use crate::input::{Source, TemplateInput};
@@ -87,6 +89,14 @@ struct Generator<'a, 'h> {
     is_in_filter_block: usize,
     /// Set of called macros we are currently in. Used to prevent (indirect) recursions.
     seen_callers: Vec<(&'a Macro<'a>, Option<FileInfo<'a>>)>,
+    /// The directory path of the calling file.
+    caller_dir: CallerDir,
+}
+
+enum CallerDir {
+    Valid(PathBuf),
+    Invalid,
+    Unresolved,
 }
 
 impl<'a, 'h> Generator<'a, 'h> {
@@ -112,6 +122,42 @@ impl<'a, 'h> Generator<'a, 'h> {
             },
             is_in_filter_block,
             seen_callers: Vec::new(),
+            caller_dir: CallerDir::Unresolved,
+        }
+    }
+
+    fn rel_path<'p>(&mut self, path: &'p Path) -> Cow<'p, Path> {
+        self.caller_dir()
+            .and_then(|caller_dir| diff_paths(path, caller_dir))
+            .map_or(Cow::Borrowed(path), Cow::Owned)
+    }
+
+    fn caller_dir(&mut self) -> Option<&Path> {
+        match self.caller_dir {
+            CallerDir::Valid(ref caller_dir) => return Some(caller_dir.as_path()),
+            CallerDir::Invalid => return None,
+            CallerDir::Unresolved => {}
+        }
+
+        if proc_macro::is_available()
+            && let Some(mut local_file) = proc_macro::Span::call_site().local_file()
+        {
+            local_file.pop();
+            if !local_file.is_absolute() {
+                local_file = current_dir()
+                    .as_deref()
+                    .unwrap_or(Path::new("."))
+                    .join(local_file);
+            }
+
+            self.caller_dir = CallerDir::Valid(clean_path(&local_file));
+            match &self.caller_dir {
+                CallerDir::Valid(caller_dir) => Some(caller_dir.as_path()),
+                _ => None, // unreachable
+            }
+        } else {
+            self.caller_dir = CallerDir::Invalid;
+            None
         }
     }
 
@@ -148,8 +194,8 @@ impl<'a, 'h> Generator<'a, 'h> {
         if let Some(full_config_path) = &self.input.config.full_config_path {
             buf.write(format_args!(
                 "const _: &[askama::helpers::core::primitive::u8] =\
-                askama::helpers::core::include_bytes!({:?});",
-                full_config_path.display()
+                    askama::helpers::core::include_bytes!({:?});",
+                self.rel_path(full_config_path).display()
             ));
         }
 
@@ -170,8 +216,8 @@ impl<'a, 'h> Generator<'a, 'h> {
             if path_is_valid {
                 buf.write(format_args!(
                     "const _: &[askama::helpers::core::primitive::u8] =\
-                        askama::helpers::core::include_bytes!({:#?});",
-                    path.canonicalize().as_deref().unwrap_or(path),
+                        askama::helpers::core::include_bytes!({:?});",
+                    self.rel_path(path).display()
                 ));
             }
         }

askama_derive/src/generator/helpers/mod.rs

@@ -1,3 +1,5 @@
 mod macro_invocation;
+mod paths;
 
-pub(crate) use macro_invocation::*;
+pub(crate) use macro_invocation::MacroInvocation;
+pub(crate) use paths::{clean as clean_path, diff_paths};

askama_derive/src/generator/helpers/paths.rs

@@ -0,0 +1,125 @@
+use std::path::{Component, Path, PathBuf};
+
+// The function [`clean()`] was copied from the project [`path_clean`] in version 1.0.1 (rev. [`d8948ae`]).
+// License: MIT OR Apache-2.0.
+// Authors: Dan Reeves <hey@danreev.es>, Alex Guerra <alex@heyimalex.com>, Adam Reichold
+//
+// The function [`diff_paths()`] was copied in from the project [`pathdiff`] in version 0.2.3 (rev. [`5180ff5`]).
+// License: MIT OR Apache-2.0.
+// Copyright 2012-2015 The Rust Project Developers.
+//
+// Please see their commit history for more information.
+//
+// [`path_clean`]: <https://github.com/danreeves/path-clean>
+// [`pathdiff`]: <https://github.com/Manishearth/pathdiff>
+// [`d8948ae`]: <https://github.com/danreeves/path-clean/blob/d8948ae69d349ec33dfe6d6b9c6a0fe30288a117/src/lib.rs#L50-L86>
+// [`5180ff5`]: <https://github.com/Manishearth/pathdiff/blob/5180ff5b23d9d7eef0a14de13a3d814eb5d8d65c/src/lib.rs#L18-L86>
+
+/// The core implementation. It performs the following, lexically:
+/// 1. Reduce multiple slashes to a single slash.
+/// 2. Eliminate `.` path name elements (the current directory).
+/// 3. Eliminate `..` path name elements (the parent directory) and the non-`.` non-`..`, element that precedes them.
+/// 4. Eliminate `..` elements that begin a rooted path, that is, replace `/..` by `/` at the beginning of a path.
+/// 5. Leave intact `..` elements that begin a non-rooted path.
+///
+/// If the result of this process is an empty string, return the string `"."`, representing the current directory.
+pub(crate) fn clean(path: &Path) -> PathBuf {
+    let mut out = Vec::new();
+    for comp in path.components() {
+        match comp {
+            Component::CurDir => (),
+            Component::ParentDir => match out.last() {
+                Some(Component::RootDir) => (),
+                Some(Component::Normal(_)) => {
+                    out.pop();
+                }
+                None
+                | Some(Component::CurDir)
+                | Some(Component::ParentDir)
+                | Some(Component::Prefix(_)) => out.push(comp),
+            },
+            comp => out.push(comp),
+        }
+    }
+    if !out.is_empty() {
+        out.iter().collect()
+    } else {
+        PathBuf::from(".")
+    }
+}
+
+/// Construct a relative path from a provided base directory path to the provided path.
+pub(crate) fn diff_paths(path: &Path, base: &Path) -> Option<PathBuf> {
+    if path.is_absolute() != base.is_absolute() {
+        if path.is_absolute() {
+            Some(PathBuf::from(path))
+        } else {
+            None
+        }
+    } else {
+        let mut ita = path.components();
+        let mut itb = base.components();
+        let mut comps = vec![];
+        loop {
+            match (ita.next(), itb.next()) {
+                (None, None) => break,
+                (Some(a), None) => {
+                    comps.push(a);
+                    comps.extend(ita.by_ref());
+                    break;
+                }
+                (None, _) => comps.push(Component::ParentDir),
+                (Some(a), Some(b)) if comps.is_empty() && a == b => (),
+                (Some(a), Some(Component::CurDir)) => comps.push(a),
+                (Some(_), Some(Component::ParentDir)) => return None,
+                (Some(a), Some(_)) => {
+                    comps.push(Component::ParentDir);
+                    for _ in itb {
+                        comps.push(Component::ParentDir);
+                    }
+                    comps.push(a);
+                    comps.extend(ita.by_ref());
+                    break;
+                }
+            }
+        }
+        Some(comps.iter().map(|c| c.as_os_str()).collect())
+    }
+}
+
+#[test]
+fn test_diff_paths() {
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar"), Path::new("/foo/bar/baz")),
+        Some("../".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar/baz"), Path::new("/foo/bar")),
+        Some("baz".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar/quux"), Path::new("/foo/bar/baz")),
+        Some("../quux".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar/baz"), Path::new("/foo/bar/quux")),
+        Some("../baz".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar"), Path::new("/foo/bar/quux")),
+        Some("../".into())
+    );
+
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar"), Path::new("baz")),
+        Some("/foo/bar".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("/foo/bar"), Path::new("/baz")),
+        Some("../foo/bar".into())
+    );
+    assert_eq!(
+        diff_paths(Path::new("foo"), Path::new("bar")),
+        Some("../foo".into())
+    );
+}

askama_derive/src/lib.rs

@@ -2,6 +2,8 @@
 #![deny(elided_lifetimes_in_paths)]
 #![deny(unreachable_pub)]
 
+extern crate proc_macro;
+
 mod config;
 mod generator;
 mod heritage;
@@ -14,8 +16,6 @@ mod tests;
 #[doc(hidden)]
 #[cfg(feature = "proc-macro")]
 pub mod __macro_support {
-    extern crate proc_macro;
-
     pub use proc_macro::TokenStream as TokenStream1;
     pub use proc_macro2::TokenStream as TokenStream2;
     pub use quote::quote;