Files
wasmtime/lib/filecheck/src/checker.rs
Jakob Stoklund Olesen 0764df28b5 Move library crates under 'lib/'.
Give these crates each a more standard directory layout with sources in
a 'src' sub-sirectory and Cargo.toml in the top lib/foo directory.

Add license and description fields to each.

The build script for the cretonne crate now lives in
'lib/cretonne/build.rs' separating it from the normal library sources
under 'lib/cretonne/src'.
2016-10-17 14:44:43 -07:00

420 lines
15 KiB
Rust

use error::{Error, Result};
use variable::{VariableMap, Value, varname_prefix};
use pattern::Pattern;
use regex::{Regex, Captures};
use std::borrow::Cow;
use std::collections::HashMap;
use std::cmp::max;
use std::fmt::{self, Display, Formatter};
use MatchRange;
use explain::{Recorder, Explainer};
// The different kinds of directives we support.
enum Directive {
Check(Pattern),
SameLn(Pattern),
NextLn(Pattern),
Unordered(Pattern),
Not(Pattern),
Regex(String, String),
}
// Regular expression matching a directive.
// The match groups are:
//
// 1. Keyword.
// 2. Rest of line / pattern.
//
const DIRECTIVE_RX: &'static str = r"\b(check|sameln|nextln|unordered|not|regex):\s+(.*)";
impl Directive {
/// Create a new directive from a `DIRECTIVE_RX` match.
fn new(caps: Captures) -> Result<Directive> {
let cmd = caps.at(1).expect("group 1 must match");
let rest = caps.at(2).expect("group 2 must match");
if cmd == "regex" {
return Directive::regex(rest);
}
// All other commands are followed by a pattern.
let pat = try!(rest.parse());
match cmd {
"check" => Ok(Directive::Check(pat)),
"sameln" => Ok(Directive::SameLn(pat)),
"nextln" => Ok(Directive::NextLn(pat)),
"unordered" => Ok(Directive::Unordered(pat)),
"not" => {
if !pat.defs().is_empty() {
let msg = format!("can't define variables '$({}=...' in not: {}",
pat.defs()[0],
rest);
Err(Error::DuplicateDef(msg))
} else {
Ok(Directive::Not(pat))
}
}
_ => panic!("unexpected command {} in regex match", cmd),
}
}
/// Create a `regex:` directive from a `VAR=...` string.
fn regex(rest: &str) -> Result<Directive> {
let varlen = varname_prefix(rest);
if varlen == 0 {
return Err(Error::Syntax(format!("invalid variable name in regex: {}", rest)));
}
let var = rest[0..varlen].to_string();
if !rest[varlen..].starts_with("=") {
return Err(Error::Syntax(format!("expected '=' after variable '{}' in regex: {}",
var,
rest)));
}
Ok(Directive::Regex(var, rest[varlen + 1..].to_string()))
}
}
/// Builder for constructing a `Checker` instance.
pub struct CheckerBuilder {
directives: Vec<Directive>,
linerx: Regex,
}
impl CheckerBuilder {
/// Create a new, blank `CheckerBuilder`.
pub fn new() -> CheckerBuilder {
CheckerBuilder {
directives: Vec::new(),
linerx: Regex::new(DIRECTIVE_RX).unwrap(),
}
}
/// Add a potential directive line.
///
/// Returns true if this is a a directive with one of the known prefixes.
/// Returns false if no known directive was found.
/// Returns an error if there is a problem with the directive.
pub fn directive(&mut self, l: &str) -> Result<bool> {
match self.linerx.captures(l) {
Some(caps) => {
self.directives.push(try!(Directive::new(caps)));
Ok(true)
}
None => Ok(false),
}
}
/// Add multiple directives.
///
/// The text is split into lines that are added individually as potential directives.
/// This method can be used to parse a whole test file containing multiple directives.
pub fn text(&mut self, t: &str) -> Result<&mut Self> {
for caps in self.linerx.captures_iter(t) {
self.directives.push(try!(Directive::new(caps)));
}
Ok(self)
}
/// Get the finished `Checker`.
pub fn finish(&mut self) -> Checker {
// Move directives into the new checker, leaving `self.directives` empty and ready for
// building a new checker.
Checker::new(self.directives.split_off(0))
}
}
/// Verify a list of directives against a test input.
///
/// Use a `CheckerBuilder` to construct a `Checker`. Then use the `test` method to verify the list
/// of directives against a test input.
pub struct Checker {
directives: Vec<Directive>,
}
impl Checker {
fn new(directives: Vec<Directive>) -> Checker {
Checker { directives: directives }
}
/// An empty checker contains no directives, and will match any input string.
pub fn is_empty(&self) -> bool {
self.directives.is_empty()
}
/// Verify directives against the input text.
///
/// This returns `true` if the text matches all the directives, `false` if it doesn't.
/// An error is only returned if there is a problem with the directives.
pub fn check(&self, text: &str, vars: &VariableMap) -> Result<bool> {
self.run(text, vars, &mut ())
}
/// Explain how directives are matched against the input text.
pub fn explain(&self, text: &str, vars: &VariableMap) -> Result<(bool, String)> {
let mut expl = Explainer::new(text);
let success = try!(self.run(text, vars, &mut expl));
expl.finish();
Ok((success, expl.to_string()))
}
fn run(&self, text: &str, vars: &VariableMap, recorder: &mut Recorder) -> Result<bool> {
let mut state = State::new(text, vars, recorder);
// For each pending `not:` check, store (begin-offset, regex).
let mut nots = Vec::new();
for (dct_idx, dct) in self.directives.iter().enumerate() {
let (pat, range) = match *dct {
Directive::Check(ref pat) => (pat, state.check()),
Directive::SameLn(ref pat) => (pat, state.sameln()),
Directive::NextLn(ref pat) => (pat, state.nextln()),
Directive::Unordered(ref pat) => (pat, state.unordered(pat)),
Directive::Not(ref pat) => {
// Resolve `not:` directives immediately to get the right variable values, but
// don't match it until we know the end of the range.
//
// The `not:` directives test the same range as `unordered:` directives. In
// particular, if they refer to defined variables, their range is restricted to
// the text following the match that defined the variable.
nots.push((dct_idx, state.unordered_begin(pat), try!(pat.resolve(&state))));
continue;
}
Directive::Regex(ref var, ref rx) => {
state.vars.insert(var.clone(),
VarDef {
value: Value::Regex(Cow::Borrowed(rx)),
offset: 0,
});
continue;
}
};
// Check if `pat` matches in `range`.
state.recorder.directive(dct_idx);
if let Some((match_begin, match_end)) = try!(state.match_positive(pat, range)) {
if let &Directive::Unordered(_) = dct {
// This was an unordered unordered match.
// Keep track of the largest matched position, but leave `last_ordered` alone.
state.max_match = max(state.max_match, match_end);
} else {
// Ordered match.
state.last_ordered = match_end;
state.max_match = match_end;
// Verify any pending `not:` directives now that we know their range.
for (not_idx, not_begin, rx) in nots.drain(..) {
state.recorder.directive(not_idx);
if let Some((s, e)) = rx.find(&text[not_begin..match_begin]) {
// Matched `not:` pattern.
state.recorder.matched_not(rx.as_str(), (not_begin + s, not_begin + e));
return Ok(false);
} else {
state.recorder.missed_not(rx.as_str(), (not_begin, match_begin));
}
}
}
} else {
// No match!
return Ok(false);
}
}
// Verify any pending `not:` directives after the last ordered directive.
for (not_idx, not_begin, rx) in nots.drain(..) {
state.recorder.directive(not_idx);
if let Some(_) = rx.find(&text[not_begin..]) {
// Matched `not:` pattern.
// TODO: Use matched range for an error message.
return Ok(false);
}
}
Ok(true)
}
}
/// A local definition of a variable.
pub struct VarDef<'a> {
/// The value given to the variable.
value: Value<'a>,
/// Offset in input text from where the variable is available.
offset: usize,
}
struct State<'a> {
text: &'a str,
env_vars: &'a VariableMap,
recorder: &'a mut Recorder,
vars: HashMap<String, VarDef<'a>>,
// Offset after the last ordered match. This does not include recent unordered matches.
last_ordered: usize,
// Largest offset following a positive match, including unordered matches.
max_match: usize,
}
impl<'a> State<'a> {
fn new(text: &'a str, env_vars: &'a VariableMap, recorder: &'a mut Recorder) -> State<'a> {
State {
text: text,
env_vars: env_vars,
recorder: recorder,
vars: HashMap::new(),
last_ordered: 0,
max_match: 0,
}
}
// Get the offset following the match that defined `var`, or 0 if var is an environment
// variable or unknown.
fn def_offset(&self, var: &str) -> usize {
self.vars.get(var).map(|&VarDef { offset, .. }| offset).unwrap_or(0)
}
// Get the offset of the beginning of the next line after `pos`.
fn bol(&self, pos: usize) -> usize {
if let Some(offset) = self.text[pos..].find('\n') {
pos + offset + 1
} else {
self.text.len()
}
}
// Get the range in text to be matched by a `check:`.
fn check(&self) -> MatchRange {
(self.max_match, self.text.len())
}
// Get the range in text to be matched by a `sameln:`.
fn sameln(&self) -> MatchRange {
let b = self.max_match;
let e = self.bol(b);
(b, e)
}
// Get the range in text to be matched by a `nextln:`.
fn nextln(&self) -> MatchRange {
let b = self.bol(self.max_match);
let e = self.bol(b);
(b, e)
}
// Get the beginning of the range in text to be matched by a `unordered:` or `not:` directive.
// The unordered directive must match after the directives that define the variables used.
fn unordered_begin(&self, pat: &Pattern) -> usize {
pat.parts()
.iter()
.filter_map(|part| part.ref_var())
.map(|var| self.def_offset(var))
.fold(self.last_ordered, max)
}
// Get the range in text to be matched by a `unordered:` directive.
fn unordered(&self, pat: &Pattern) -> MatchRange {
(self.unordered_begin(pat), self.text.len())
}
// Search for `pat` in `range`, return the range matched.
// After a positive match, update variable definitions, if any.
fn match_positive(&mut self, pat: &Pattern, range: MatchRange) -> Result<Option<MatchRange>> {
let rx = try!(pat.resolve(self));
let txt = &self.text[range.0..range.1];
let defs = pat.defs();
let matched_range = if defs.is_empty() {
// Pattern defines no variables. Fastest search is `find`.
rx.find(txt)
} else {
// We need the captures to define variables.
rx.captures(txt).map(|caps| {
let matched_range = caps.pos(0).expect("whole expression must match");
for var in defs {
let txtval = caps.name(var).unwrap_or("");
self.recorder.defined_var(var, txtval);
let vardef = VarDef {
value: Value::Text(Cow::Borrowed(txtval)),
// This offset is the end of the whole matched pattern, not just the text
// defining the variable.
offset: range.0 + matched_range.1,
};
self.vars.insert(var.clone(), vardef);
}
matched_range
})
};
Ok(if let Some((b, e)) = matched_range {
let r = (range.0 + b, range.0 + e);
self.recorder.matched_check(rx.as_str(), r);
Some(r)
} else {
self.recorder.missed_check(rx.as_str(), range);
None
})
}
}
impl<'a> VariableMap for State<'a> {
fn lookup(&self, varname: &str) -> Option<Value> {
// First look for a local define.
if let Some(&VarDef { ref value, .. }) = self.vars.get(varname) {
Some(value.clone())
} else {
// No local, maybe an environment variable?
self.env_vars.lookup(varname)
}
}
}
impl Display for Directive {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
use self::Directive::*;
match *self {
Check(ref pat) => writeln!(f, "check: {}", pat),
SameLn(ref pat) => writeln!(f, "sameln: {}", pat),
NextLn(ref pat) => writeln!(f, "nextln: {}", pat),
Unordered(ref pat) => writeln!(f, "unordered: {}", pat),
Not(ref pat) => writeln!(f, "not: {}", pat),
Regex(ref var, ref rx) => writeln!(f, "regex: {}={}", var, rx),
}
}
}
impl Display for Checker {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
for (idx, dir) in self.directives.iter().enumerate() {
try!(write!(f, "#{} {}", idx, dir));
}
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::CheckerBuilder;
use error::Error;
fn e2s(e: Error) -> String {
e.to_string()
}
#[test]
fn directive() {
let mut b = CheckerBuilder::new();
assert_eq!(b.directive("not here: more text").map_err(e2s), Ok(false));
assert_eq!(b.directive("not here: regex: X=more text").map_err(e2s),
Ok(true));
assert_eq!(b.directive("regex: X = tommy").map_err(e2s),
Err("expected '=' after variable 'X' in regex: X = tommy".to_string()));
assert_eq!(b.directive("[arm]not: patt $x $(y) here").map_err(e2s),
Ok(true));
assert_eq!(b.directive("[x86]sameln: $x $(y=[^]]*) there").map_err(e2s),
Ok(true));
let c = b.finish();
assert_eq!(c.to_string(),
"#0 regex: X=more text\n#1 not: patt $(x) $(y) here\n#2 sameln: $(x) \
$(y=[^]]*) there\n");
}
}