Move the filetest harness into its own crate.

This allows us to run the tests via a library call rather than just
as a command execution. And, it's a step toward a broader goal, which
is to keep the code in the top-level src directory minimal, with
important functionality exposed as crates.

cranelift/src/utils.rs

@@ -1,13 +1,9 @@
 //! Utility functions.
 
-use cretonne::ir::entities::AnyEntity;
-use cretonne::{ir, verifier};
-use cretonne::result::CtonError;
 use cretonne::isa::TargetIsa;
 use cretonne::settings::{self, FlagsOrIsa};
 use cretonne::isa;
 use cton_reader::{parse_options, Location};
-use std::fmt::Write;
 use std::fs::File;
 use std::io::{self, Read};
 use std::path::Path;
@@ -28,51 +24,6 @@ pub fn read_to_end<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> {
     Ok(buffer)
 }
 
-/// Look for a directive in a comment string.
-/// The directive is of the form "foo:" and should follow the leading `;` in the comment:
-///
-/// ; dominates: ebb3 ebb4
-///
-/// Return the comment text following the directive.
-pub fn match_directive<'a>(comment: &'a str, directive: &str) -> Option<&'a str> {
-    assert!(
-        directive.ends_with(':'),
-        "Directive must include trailing colon"
-    );
-    let text = comment.trim_left_matches(';').trim_left();
-    if text.starts_with(directive) {
-        Some(text[directive.len()..].trim())
-    } else {
-        None
-    }
-}
-
-/// Pretty-print a verifier error.
-pub fn pretty_verifier_error(
-    func: &ir::Function,
-    isa: Option<&TargetIsa>,
-    err: verifier::Error,
-) -> String {
-    let mut msg = err.to_string();
-    match err.location {
-        AnyEntity::Inst(inst) => {
-            write!(msg, "\n{}: {}\n\n", inst, func.dfg.display_inst(inst, isa)).unwrap()
-        }
-        _ => msg.push('\n'),
-    }
-    write!(msg, "{}", func.display(isa)).unwrap();
-    msg
-}
-
-/// Pretty-print a Cretonne error.
-pub fn pretty_error(func: &ir::Function, isa: Option<&TargetIsa>, err: CtonError) -> String {
-    if let CtonError::Verifier(e) = err {
-        pretty_verifier_error(func, isa, e)
-    } else {
-        err.to_string()
-    }
-}
-
 /// Like `FlagsOrIsa`, but holds ownership.
 pub enum OwnedFlagsOrIsa {
     Flags(settings::Flags),
@@ -119,12 +70,3 @@ pub fn parse_sets_and_isa(
         Ok(OwnedFlagsOrIsa::Flags(settings::Flags::new(&flag_builder)))
     }
 }
-
-#[test]
-fn test_match_directive() {
-    assert_eq!(match_directive("; foo: bar  ", "foo:"), Some("bar"));
-    assert_eq!(match_directive(" foo:bar", "foo:"), Some("bar"));
-    assert_eq!(match_directive("foo:bar", "foo:"), Some("bar"));
-    assert_eq!(match_directive(";x foo: bar", "foo:"), None);
-    assert_eq!(match_directive(";;; foo: bar", "foo:"), Some("bar"));
-}