Rewrite the compiletest directive parser

Author: tgross35

Cargo.lock

@@ -822,6 +822,7 @@ dependencies = [
  "rustfix 0.8.1",
  "serde",
  "serde_json",
+ "strsim",
  "tracing",
  "tracing-subscriber",
  "unified-diff",

src/tools/compiletest/Cargo.toml

@@ -25,6 +25,7 @@ walkdir = "2"
 glob = "0.3.0"
 anyhow = "1"
 home = "0.5.5"
+strsim = "0.11.1"
 
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"

src/tools/compiletest/src/lib.rs

@@ -13,6 +13,7 @@ pub mod compute_diff;
 pub mod errors;
 pub mod header;
 mod json;
+mod load_cfg;
 mod raise_fd_limit;
 mod read2;
 pub mod runtest;

src/tools/compiletest/src/load_cfg.rs

@@ -0,0 +1,169 @@
+#![allow(unused)]
+
+mod itemlist;
+mod prepare;
+
+use error::{Error, ErrorExt, Result};
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub struct LineCol {
+    pub line: usize,
+    pub col: usize,
+}
+
+impl LineCol {
+    const fn new(line: usize, col: usize) -> Self {
+        Self { line, col }
+    }
+}
+
+/// When we need to e.g. build regexes that include a pattern, we need to know what kind of
+/// comments to use. Usually we just build a regex for all expressions, even though we don't
+/// use them.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+enum CommentTy {
+    Slashes,
+    Hash,
+    Semi,
+}
+
+impl CommentTy {
+    const fn as_str(self) -> &'static str {
+        match self {
+            CommentTy::Slashes => "//",
+            CommentTy::Hash => "#",
+            CommentTy::Semi => ";",
+        }
+    }
+
+    const fn directive(self) -> &'static str {
+        match self {
+            CommentTy::Slashes => "//@",
+            CommentTy::Hash => "#@",
+            CommentTy::Semi => ";@",
+        }
+    }
+
+    const fn all() -> &'static [Self] {
+        &[Self::Slashes, Self::Hash, Self::Semi]
+    }
+}
+
+/// Errors used within the `load_cfg` module
+mod error {
+    use std::fmt;
+    use std::path::{Path, PathBuf};
+
+    use super::LineCol;
+
+    pub type Error = Box<dyn std::error::Error>;
+    pub type Result<T, E = Error> = std::result::Result<T, E>;
+
+    #[derive(Debug)]
+    struct FullError {
+        msg: Box<str>,
+        fname: Option<PathBuf>,
+        pos: Option<LineCol>,
+        context: Vec<Box<str>>,
+    }
+
+    impl fmt::Display for FullError {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            write!(f, "error: {}", self.msg)?;
+
+            let path = self.fname.as_ref().map_or(Path::new("unknown").display(), |p| p.display());
+            write!(f, "\n parsing '{path}'",)?;
+
+            let pos = self.pos.unwrap_or_default();
+            write!(f, " at line {}, column {}", pos.line, pos.col)?;
+
+            if !self.context.is_empty() {
+                write!(f, "\ncontext: {:#?}", self.context)?;
+            }
+
+            Ok(())
+        }
+    }
+
+    impl std::error::Error for FullError {}
+
+    /// Give us an easy way to tack context onto an error.
+    pub trait ErrorExt {
+        fn pos(self, pos: LineCol) -> Self;
+        fn line(self, line: usize) -> Self;
+        fn col(self, col: usize) -> Self;
+        fn fname(self, fname: impl Into<PathBuf>) -> Self;
+        fn context(self, ctx: impl Into<Box<str>>) -> Self;
+    }
+
+    impl ErrorExt for Error {
+        fn pos(self, pos: LineCol) -> Self {
+            let mut fe = to_fullerr(self);
+            fe.pos = Some(pos);
+            fe
+        }
+
+        fn line(self, line: usize) -> Self {
+            let mut fe = to_fullerr(self);
+            match fe.pos.as_mut() {
+                Some(v) => v.line = line,
+                None => fe.pos = Some(LineCol::new(line, 0)),
+            };
+            fe
+        }
+
+        fn col(self, col: usize) -> Self {
+            let mut fe = to_fullerr(self);
+            match fe.pos.as_mut() {
+                Some(v) => v.col = col,
+                None => fe.pos = Some(LineCol::new(0, col)),
+            };
+            fe
+        }
+
+        fn fname(self, fname: impl Into<PathBuf>) -> Self {
+            let mut fe = to_fullerr(self);
+            fe.fname = Some(fname.into());
+            fe
+        }
+
+        fn context(self, ctx: impl Into<Box<str>>) -> Self {
+            let mut fe = to_fullerr(self);
+            fe.context.push(ctx.into());
+            fe
+        }
+    }
+
+    impl<T> ErrorExt for Result<T> {
+        fn pos(self, pos: LineCol) -> Self {
+            self.map_err(|e| e.pos(pos))
+        }
+
+        fn line(self, line: usize) -> Self {
+            self.map_err(|e| e.line(line))
+        }
+
+        fn col(self, col: usize) -> Self {
+            self.map_err(|e| e.col(col))
+        }
+
+        fn fname(self, fname: impl Into<PathBuf>) -> Self {
+            self.map_err(|e| e.fname(fname))
+        }
+
+        fn context(self, ctx: impl Into<Box<str>>) -> Self {
+            self.map_err(|e| e.context(ctx))
+        }
+    }
+
+    fn to_fullerr(e: Error) -> Box<FullError> {
+        e.downcast().unwrap_or_else(|e| {
+            Box::new(FullError {
+                msg: e.to_string().into(),
+                fname: None,
+                pos: None,
+                context: Vec::new(),
+            })
+        })
+    }
+}