lrlex/
ctbuilder.rs

1//! Build grammars at run-time.
2
3use std::{
4    any::type_name,
5    borrow::Borrow,
6    collections::{HashMap, HashSet},
7    env::{current_dir, var},
8    error::Error,
9    fmt::{self, Debug, Display, Write as _},
10    fs::{self, create_dir_all, read_to_string, File},
11    hash::Hash,
12    io::Write,
13    path::{Path, PathBuf},
14    sync::Mutex,
15};
16
17use bincode::Encode;
18use cfgrammar::{
19    header::{
20        GrmtoolsSectionParser, Header, HeaderError, HeaderErrorKind, HeaderValue, Namespaced,
21        Setting, Value,
22    },
23    markmap::MergeBehavior,
24    span::{Location, Span},
25};
26use glob::glob;
27use lazy_static::lazy_static;
28use lrpar::{
29    diagnostics::{DiagnosticFormatter, SpannedDiagnosticFormatter},
30    CTParserBuilder, LexerTypes,
31};
32use num_traits::{AsPrimitive, PrimInt, Unsigned};
33use proc_macro2::TokenStream;
34use quote::{format_ident, quote, ToTokens, TokenStreamExt};
35use regex::Regex;
36
37use crate::{DefaultLexerTypes, LRNonStreamingLexer, LRNonStreamingLexerDef, LexFlags, LexerDef};
38
39const RUST_FILE_EXT: &str = "rs";
40
41const ERROR: &str = "[Error]";
42const WARNING: &str = "[Warning]";
43
44lazy_static! {
45    static ref RE_TOKEN_ID: Regex = Regex::new(r"^[a-zA-Z_][a-zA-Z_0-9]*$").unwrap();
46    static ref GENERATED_PATHS: Mutex<HashSet<PathBuf>> = Mutex::new(HashSet::new());
47}
48
49#[non_exhaustive]
50pub enum LexerKind {
51    LRNonStreamingLexer,
52}
53
54impl<T: Clone> TryFrom<&Value<T>> for LexerKind {
55    type Error = cfgrammar::header::HeaderError<T>;
56    fn try_from(it: &Value<T>) -> Result<LexerKind, Self::Error> {
57        match it {
58            Value::Flag(_, loc) => Err(HeaderError {
59                kind: HeaderErrorKind::ConversionError(
60                    "LexerKind",
61                    "Expected `LexerKind` found bool",
62                ),
63                locations: vec![loc.clone()],
64            }),
65            Value::Setting(Setting::Num(_, loc)) => Err(HeaderError {
66                kind: HeaderErrorKind::ConversionError(
67                    "LexerKind",
68                    "Expected `LexerKind` found numeric",
69                ),
70                locations: vec![loc.clone()],
71            }),
72            Value::Setting(Setting::String(_, loc)) => Err(HeaderError {
73                kind: HeaderErrorKind::ConversionError(
74                    "LexerKind",
75                    "Expected `LexerKind` found string",
76                ),
77                locations: vec![loc.clone()],
78            }),
79            Value::Setting(Setting::Constructor {
80                ctor:
81                    Namespaced {
82                        namespace: _,
83                        member: (_, loc),
84                    },
85                arg: _,
86            }) => Err(HeaderError {
87                kind: HeaderErrorKind::ConversionError(
88                    "LexerKind",
89                    "Expected `LexerKind` found constructor",
90                ),
91                locations: vec![loc.clone()],
92            }),
93            Value::Setting(Setting::Unitary(Namespaced {
94                namespace,
95                member: (member, member_loc),
96            })) => {
97                if let Some((ns, loc)) = namespace {
98                    if ns.to_lowercase() != "lexerkind" {
99                        return Err(HeaderError {
100                            kind: HeaderErrorKind::ConversionError(
101                                "LexerKind",
102                                "Expected namespace `LexerKind`",
103                            ),
104                            locations: vec![loc.clone()],
105                        });
106                    }
107                }
108                if member.to_lowercase() != "lrnonstreaminglexer" {
109                    return Err(HeaderError {
110                        kind: HeaderErrorKind::ConversionError(
111                            "LexerKind",
112                            "Unknown `LexerKind` Variant",
113                        ),
114                        locations: vec![member_loc.clone()],
115                    });
116                }
117
118                Ok(LexerKind::LRNonStreamingLexer)
119            }
120        }
121    }
122}
123
124/// Specify the visibility of the module generated by [CTLexerBuilder].
125#[derive(Clone, PartialEq, Eq, Debug)]
126#[non_exhaustive]
127pub enum Visibility {
128    /// Module-level visibility only.
129    Private,
130    /// `pub`
131    Public,
132    /// `pub(super)`
133    PublicSuper,
134    /// `pub(self)`
135    PublicSelf,
136    /// `pub(crate)`
137    PublicCrate,
138    /// `pub(in {arg})`
139    PublicIn(String),
140}
141
142impl ToTokens for Visibility {
143    fn to_tokens(&self, tokens: &mut TokenStream) {
144        tokens.extend(match self {
145            Visibility::Private => quote!(),
146            Visibility::Public => quote! {pub},
147            Visibility::PublicSuper => quote! {pub(super)},
148            Visibility::PublicSelf => quote! {pub(self)},
149            Visibility::PublicCrate => quote! {pub(crate)},
150            Visibility::PublicIn(data) => {
151                let other = str::parse::<TokenStream>(data).unwrap();
152                quote! {pub(in #other)}
153            }
154        })
155    }
156}
157
158/// Specifies the [Rust Edition] that will be emitted during code generation.
159///
160/// [Rust Edition]: https://doc.rust-lang.org/edition-guide/rust-2021/index.html
161#[derive(Clone, Copy, PartialEq, Eq, Debug)]
162#[non_exhaustive]
163pub enum RustEdition {
164    Rust2015,
165    Rust2018,
166    Rust2021,
167}
168
169/// The quote impl of `ToTokens` for `Option` prints an empty string for `None`
170/// and the inner value for `Some(inner_value)`.
171///
172/// This wrapper instead emits both `Some` and `None` variants.
173/// See: [quote #20](https://github.com/dtolnay/quote/issues/20)
174struct QuoteOption<T>(Option<T>);
175
176impl<T: ToTokens> ToTokens for QuoteOption<T> {
177    fn to_tokens(&self, tokens: &mut TokenStream) {
178        tokens.append_all(match self.0 {
179            Some(ref t) => quote! { ::std::option::Option::Some(#t) },
180            None => quote! { ::std::option::Option::None },
181        });
182    }
183}
184
185/// This wrapper adds a missing impl of `ToTokens` for tuples.
186/// For a tuple `(a, b)` emits `(a.to_tokens(), b.to_tokens())`
187struct QuoteTuple<T>(T);
188
189impl<A: ToTokens, B: ToTokens> ToTokens for QuoteTuple<(A, B)> {
190    fn to_tokens(&self, tokens: &mut TokenStream) {
191        let (a, b) = &self.0;
192        tokens.append_all(quote!((#a, #b)));
193    }
194}
195
196/// The wrapped `&str` value will be emitted with a call to `to_string()`
197struct QuoteToString<'a>(&'a str);
198
199impl ToTokens for QuoteToString<'_> {
200    fn to_tokens(&self, tokens: &mut TokenStream) {
201        let x = &self.0;
202        tokens.append_all(quote! { #x.to_string() });
203    }
204}
205
206/// A string which uses `Display` for it's `Debug` impl.
207struct ErrorString(String);
208impl fmt::Display for ErrorString {
209    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
210        let ErrorString(s) = self;
211        write!(f, "{}", s)
212    }
213}
214impl fmt::Debug for ErrorString {
215    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
216        let ErrorString(s) = self;
217        write!(f, "{}", s)
218    }
219}
220impl Error for ErrorString {}
221
222/// A `CTLexerBuilder` allows one to specify the criteria for building a statically generated
223/// lexer.
224pub struct CTLexerBuilder<'a, LexerTypesT: LexerTypes = DefaultLexerTypes<u32>>
225where
226    LexerTypesT::StorageT: Debug + Eq + Hash + ToTokens,
227    usize: num_traits::AsPrimitive<LexerTypesT::StorageT>,
228{
229    lrpar_config: Option<Box<dyn Fn(CTParserBuilder<LexerTypesT>) -> CTParserBuilder<LexerTypesT>>>,
230    lexer_path: Option<PathBuf>,
231    output_path: Option<PathBuf>,
232    lexerkind: Option<LexerKind>,
233    mod_name: Option<&'a str>,
234    visibility: Visibility,
235    rust_edition: RustEdition,
236    rule_ids_map: Option<HashMap<String, LexerTypesT::StorageT>>,
237    allow_missing_terms_in_lexer: bool,
238    allow_missing_tokens_in_parser: bool,
239    warnings_are_errors: bool,
240    show_warnings: bool,
241    header: Header<Location>,
242    #[cfg(test)]
243    inspect_lexerkind_cb: Option<Box<dyn Fn(LexerKind) -> Result<(), Box<dyn Error>>>>,
244}
245
246impl CTLexerBuilder<'_, DefaultLexerTypes<u32>> {
247    /// Create a new [CTLexerBuilder].
248    pub fn new() -> Self {
249        CTLexerBuilder::<DefaultLexerTypes<u32>>::new_with_lexemet()
250    }
251}
252
253impl<'a, LexerTypesT: LexerTypes<LexErrorT = crate::LRLexError> + 'static>
254    CTLexerBuilder<'a, LexerTypesT>
255where
256    LexerTypesT::StorageT:
257        'static + Debug + Eq + Hash + PrimInt + Encode + TryFrom<usize> + Unsigned + ToTokens,
258    usize: AsPrimitive<LexerTypesT::StorageT>,
259{
260    /// Create a new [CTLexerBuilder].
261    ///
262    /// `LexerTypesT::StorageT` must be an unsigned integer type (e.g. `u8`, `u16`) which is big enough
263    /// to index all the tokens, rules, and productions in the lexer and less than or equal in size
264    /// to `usize` (e.g. on a 64-bit machine `u128` would be too big). If you are lexing large
265    /// files, the additional storage requirements of larger integer types can be noticeable, and
266    /// in such cases it can be worth specifying a smaller type. `StorageT` defaults to `u32` if
267    /// unspecified.
268    ///
269    /// # Examples
270    ///
271    /// ```text
272    /// CTLexerBuilder::<DefaultLexerTypes<u8>>::new_with_lexemet()
273    ///     .lexer_in_src_dir("grm.l", None)?
274    ///     .build()?;
275    /// ```
276    pub fn new_with_lexemet() -> Self {
277        let mut header = Header::new();
278        header.set_default_merge_behavior(MergeBehavior::Ours);
279        CTLexerBuilder {
280            lrpar_config: None,
281            lexer_path: None,
282            output_path: None,
283            lexerkind: None,
284            mod_name: None,
285            visibility: Visibility::Private,
286            rust_edition: RustEdition::Rust2021,
287            rule_ids_map: None,
288            allow_missing_terms_in_lexer: false,
289            allow_missing_tokens_in_parser: false,
290            warnings_are_errors: false,
291            show_warnings: true,
292            header,
293            #[cfg(test)]
294            inspect_lexerkind_cb: None,
295        }
296    }
297
298    /// An optional convenience function to make it easier to create an (lrlex) lexer and (lrpar)
299    /// parser in one shot. The closure passed to this function will be called during
300    /// [CTLexerBuilder::build]: it will be passed an lrpar `CTParserBuilder` instance upon which
301    /// it can set whatever lrpar options are desired. [`CTLexerBuilder`] will then create both the
302    /// compiler and lexer and link them together as required.
303    ///
304    /// # Examples
305    ///
306    /// ```text
307    /// CTLexerBuilder:::new()
308    ///     .lrpar_config(|ctp| {
309    ///         ctp.yacckind(YaccKind::Grmtools)
310    ///             .grammar_in_src_dir("calc.y")
311    ///             .unwrap()
312    ///     })
313    ///     .lexer_in_src_dir("calc.l")?
314    ///     .build()?;
315    /// ```
316    pub fn lrpar_config<F>(mut self, config_func: F) -> Self
317    where
318        F: 'static + Fn(CTParserBuilder<LexerTypesT>) -> CTParserBuilder<LexerTypesT>,
319    {
320        self.lrpar_config = Some(Box::new(config_func));
321        self
322    }
323
324    /// Set the input lexer path to a file relative to this project's `src` directory. This will
325    /// also set the output path (i.e. you do not need to call [CTLexerBuilder::output_path]).
326    ///
327    /// For example if `a/b.l` is passed as `inp` then [CTLexerBuilder::build] will:
328    ///   * use `src/a/b.l` as the input file.
329    ///   * write output to a file which can then be imported by calling `lrlex_mod!("a/b.l")`.
330    ///   * create a module in that output file named `b_l`.
331    ///
332    /// You can override the output path and/or module name by calling
333    /// [CTLexerBuilder::output_path] and/or [CTLexerBuilder::mod_name], respectively, after
334    /// calling this function.
335    ///
336    /// This is a convenience function that makes it easier to compile lexer files stored in a
337    /// project's `src/` directory: please see [CTLexerBuilder::build] for additional constraints
338    /// and information about the generated files. Note also that each `.l` file can only be
339    /// processed once using this function: if you want to generate multiple lexers from a single
340    /// `.l` file, you will need to use [CTLexerBuilder::output_path].
341    pub fn lexer_in_src_dir<P>(mut self, srcp: P) -> Result<Self, Box<dyn Error>>
342    where
343        P: AsRef<Path>,
344    {
345        if !srcp.as_ref().is_relative() {
346            return Err(format!(
347                "Lexer path '{}' must be a relative path.",
348                srcp.as_ref().to_str().unwrap_or("<invalid UTF-8>")
349            )
350            .into());
351        }
352
353        let mut lexp = current_dir()?;
354        lexp.push("src");
355        lexp.push(srcp.as_ref());
356        self.lexer_path = Some(lexp);
357
358        let mut outp = PathBuf::new();
359        outp.push(var("OUT_DIR").unwrap());
360        outp.push(srcp.as_ref().parent().unwrap().to_str().unwrap());
361        create_dir_all(&outp)?;
362        let mut leaf = srcp
363            .as_ref()
364            .file_name()
365            .unwrap()
366            .to_str()
367            .unwrap()
368            .to_owned();
369        write!(leaf, ".{}", RUST_FILE_EXT).ok();
370        outp.push(leaf);
371        Ok(self.output_path(outp))
372    }
373
374    /// Set the input lexer path to `inp`. If specified, you must also call
375    /// [CTLexerBuilder::output_path]. In general it is easier to use
376    /// [CTLexerBuilder::lexer_in_src_dir].
377    pub fn lexer_path<P>(mut self, inp: P) -> Self
378    where
379        P: AsRef<Path>,
380    {
381        self.lexer_path = Some(inp.as_ref().to_owned());
382        self
383    }
384
385    /// Set the output lexer path to `outp`. Note that there are no requirements on `outp`: the
386    /// file can exist anywhere you can create a valid [Path] to. However, if you wish to use
387    /// [crate::lrlex_mod!] you will need to make sure that `outp` is in
388    /// [std::env::var]`("OUT_DIR")` or one of its subdirectories.
389    pub fn output_path<P>(mut self, outp: P) -> Self
390    where
391        P: AsRef<Path>,
392    {
393        self.output_path = Some(outp.as_ref().to_owned());
394        self
395    }
396
397    /// Set the type of lexer to be generated to `lexerkind`.
398    pub fn lexerkind(mut self, lexerkind: LexerKind) -> Self {
399        self.lexerkind = Some(lexerkind);
400        self
401    }
402
403    /// Set the generated module name to `mod_name`. If no module name is specified,
404    /// [`process_file`](#method.process_file) will attempt to create a sensible default based on
405    /// the input filename.
406    pub fn mod_name(mut self, mod_name: &'a str) -> Self {
407        self.mod_name = Some(mod_name);
408        self
409    }
410
411    /// Set the visibility of the generated module to `vis`. Defaults to `Visibility::Private`.
412    pub fn visibility(mut self, vis: Visibility) -> Self {
413        self.visibility = vis;
414        self
415    }
416
417    /// Sets the rust edition to be used for generated code. Defaults to the latest edition of
418    /// rust supported by grmtools.
419    pub fn rust_edition(mut self, edition: RustEdition) -> Self {
420        self.rust_edition = edition;
421        self
422    }
423
424    /// Set this lexer builder's map of rule IDs to `rule_ids_map`. By default, lexing rules have
425    /// arbitrary, but distinct, IDs. Setting the map of rule IDs (from rule names to `StorageT`)
426    /// allows users to synchronise a lexer and parser and to check that all rules are used by both
427    /// parts).
428    pub fn rule_ids_map<T: std::borrow::Borrow<HashMap<String, LexerTypesT::StorageT>> + Clone>(
429        mut self,
430        rule_ids_map: T,
431    ) -> Self {
432        self.rule_ids_map = Some(rule_ids_map.borrow().to_owned());
433        self
434    }
435
436    /// Statically compile the `.l` file specified by [CTLexerBuilder::lexer_path()] into Rust,
437    /// placing the output into the file specified by [CTLexerBuilder::output_path()].
438    ///
439    /// The generated module follows the form:
440    ///
441    /// ```text
442    ///    mod modname {
443    ///      pub fn lexerdef() -> LexerDef<LexerTypesT> { ... }
444    ///
445    ///      ...
446    ///    }
447    /// ```
448    ///
449    /// where:
450    ///  * `modname` is either:
451    ///    * the module name specified by [CTLexerBuilder::mod_name()]
452    ///    * or, if no module name was explicitly specified, then for the file `/a/b/c.l` the
453    ///      module name is `c_l` (i.e. the file's leaf name, minus its extension, with a prefix of
454    ///      `_l`).
455    pub fn build(mut self) -> Result<CTLexer, Box<dyn Error>> {
456        let lexerp = self
457            .lexer_path
458            .as_ref()
459            .expect("lexer_path must be specified before processing.");
460        let outp = self
461            .output_path
462            .as_ref()
463            .expect("output_path must be specified before processing.");
464
465        {
466            let mut lk = GENERATED_PATHS.lock().unwrap();
467            if lk.contains(outp.as_path()) {
468                return Err(format!("Generating two lexers to the same path ('{}') is not allowed: use CTLexerBuilder::output_path (and, optionally, CTLexerBuilder::mod_name) to differentiate them.", &outp.to_str().unwrap()).into());
469            }
470            lk.insert(outp.clone());
471        }
472        let lex_src = read_to_string(lexerp)
473            .map_err(|e| format!("When reading '{}': {e}", lexerp.display()))?;
474        let lex_diag = SpannedDiagnosticFormatter::new(&lex_src, lexerp);
475        let mut header = self.header;
476        let (parsed_header, _) = GrmtoolsSectionParser::new(&lex_src, false)
477            .parse()
478            .map_err(|es| {
479                let mut out = String::new();
480                out.push_str(&format!(
481                    "\n{ERROR}{}\n",
482                    lex_diag.file_location_msg(" parsing the `%grmtools` section", None)
483                ));
484                for e in es {
485                    out.push_str(&indent("     ", &lex_diag.format_error(e).to_string()));
486                    out.push('\n');
487                }
488                ErrorString(out)
489            })?;
490        header.merge_from(parsed_header)?;
491        header.mark_used(&"lexerkind".to_string());
492        let lexerkind = match self.lexerkind {
493            Some(lexerkind) => lexerkind,
494            None => {
495                if let Some(HeaderValue(_, lk_val)) = header.get("lexerkind") {
496                    LexerKind::try_from(lk_val)?
497                } else {
498                    LexerKind::LRNonStreamingLexer
499                }
500            }
501        };
502        #[cfg(test)]
503        if let Some(inspect_lexerkind_cb) = self.inspect_lexerkind_cb {
504            inspect_lexerkind_cb(lexerkind)?
505        }
506        let (lexerdef, lex_flags): (LRNonStreamingLexerDef<LexerTypesT>, LexFlags) =
507            match lexerkind {
508                LexerKind::LRNonStreamingLexer => {
509                    let lex_flags = LexFlags::try_from(&mut header)?;
510                    let lexerdef = LRNonStreamingLexerDef::<LexerTypesT>::new_with_options(
511                        &lex_src, lex_flags,
512                    )
513                    .map_err(|errs| {
514                        let mut out = String::new();
515                        out.push_str(&format!(
516                            "\n{ERROR}{}\n",
517                            lex_diag.file_location_msg("", None)
518                        ));
519                        for e in errs {
520                            out.push_str(&indent("     ", &lex_diag.format_error(e).to_string()));
521                            out.push('\n');
522                        }
523                        ErrorString(out)
524                    })?;
525                    let lex_flags = lexerdef.lex_flags().cloned();
526                    (lexerdef, lex_flags.unwrap())
527                }
528            };
529
530        let ct_parser = if let Some(ref lrcfg) = self.lrpar_config {
531            let mut closure_lexerdef = lexerdef.clone();
532            let mut ctp = CTParserBuilder::<LexerTypesT>::new().inspect_rt(Box::new(
533                move |yacc_header, rtpb, rule_ids_map, grm_path| {
534                    let owned_map = rule_ids_map
535                        .iter()
536                        .map(|(x, y)| (&**x, *y))
537                        .collect::<HashMap<_, _>>();
538                    closure_lexerdef.set_rule_ids(&owned_map);
539                    yacc_header.mark_used(&"test_files".to_string());
540                    let test_glob = yacc_header.get("test_files");
541                    match test_glob {
542                        Some(HeaderValue(_, Value::Setting(Setting::String(test_files, _)))) => {
543                            let path_joined = grm_path.parent().unwrap().join(test_files);
544                            for path in
545                                glob(&path_joined.to_string_lossy()).map_err(|e| e.to_string())?
546                            {
547                                let path = path?;
548                                let input = fs::read_to_string(&path)?;
549                                let l: LRNonStreamingLexer<LexerTypesT> =
550                                    closure_lexerdef.lexer(&input);
551                                for e in rtpb.parse_noaction(&l) {
552                                    Err(format!("parsing {}: {}", path.display(), e))?
553                                }
554                            }
555                            Ok(())
556                        }
557                        Some(_) => Err("Invalid value for setting 'test_files'".into()),
558                        None => Ok(()),
559                    }
560                },
561            ));
562            ctp = lrcfg(ctp);
563            let ct_parser = ctp.build()?;
564            self.rule_ids_map = Some(ct_parser.token_map().to_owned());
565            Some(ct_parser)
566        } else {
567            None
568        };
569
570        let mut lexerdef = Box::new(lexerdef);
571        let unused_header_values = header.unused();
572        if !unused_header_values.is_empty() {
573            return Err(
574                format!("Unused header values: {}", unused_header_values.join(", ")).into(),
575            );
576        }
577
578        let (missing_from_lexer, missing_from_parser) = match self.rule_ids_map {
579            Some(ref rim) => {
580                // Convert from HashMap<String, _> to HashMap<&str, _>
581                let owned_map = rim
582                    .iter()
583                    .map(|(x, y)| (&**x, *y))
584                    .collect::<HashMap<_, _>>();
585                let (x, y) = lexerdef.set_rule_ids_spanned(&owned_map);
586                (
587                    x.map(|a| a.iter().map(|&b| b.to_string()).collect::<HashSet<_>>()),
588                    y.map(|a| {
589                        a.iter()
590                            .map(|(b, span)| (b.to_string(), *span))
591                            .collect::<HashSet<_>>()
592                    }),
593                )
594            }
595            None => (None, None),
596        };
597
598        let mut has_unallowed_missing = false;
599        let err_indent = " ".repeat(ERROR.len());
600        if !self.allow_missing_terms_in_lexer {
601            if let Some(ref mfl) = missing_from_lexer {
602                if let Some(ct_parser) = &ct_parser {
603                    let grm = ct_parser.yacc_grammar();
604                    let token_spans = mfl
605                        .iter()
606                        .map(|name| {
607                            ct_parser
608                                .yacc_grammar()
609                                .token_span(*grm.tokens_map().get(name.as_str()).unwrap())
610                                .expect("Given token should have a span")
611                        })
612                        .collect::<Vec<_>>();
613
614                    let yacc_diag = SpannedDiagnosticFormatter::new(
615                        ct_parser.grammar_src(),
616                        ct_parser.grammar_path(),
617                    );
618
619                    eprintln!("{ERROR} these tokens are not referenced in the lexer but defined as follows");
620                    eprintln!(
621                        "{err_indent} {}",
622                        yacc_diag.file_location_msg("in the grammar", None)
623                    );
624                    for span in token_spans {
625                        eprintln!(
626                            "{}",
627                            yacc_diag.underline_span_with_text(
628                                span,
629                                "Missing from lexer".to_string(),
630                                '^'
631                            )
632                        );
633                    }
634                    eprintln!();
635                } else {
636                    eprintln!("{ERROR} the following tokens are used in the grammar but are not defined in the lexer:");
637                    for n in mfl {
638                        eprintln!("    {}", n);
639                    }
640                }
641                has_unallowed_missing = true;
642            }
643        }
644        if !self.allow_missing_tokens_in_parser && self.show_warnings {
645            if let Some(ref mfp) = missing_from_parser {
646                let error_prefix = if self.warnings_are_errors {
647                    ERROR
648                } else {
649                    WARNING
650                };
651                let err_indent = " ".repeat(error_prefix.len());
652                let mut outs = Vec::new();
653                outs.push(format!("{error_prefix} these tokens are not referenced in the grammar but defined as follows"));
654                outs.push(format!(
655                    "{err_indent} {}",
656                    lex_diag.file_location_msg("in the lexer", None)
657                ));
658                for (_, span) in mfp {
659                    let error_contents = lex_diag.underline_span_with_text(
660                        *span,
661                        "Missing from parser".to_string(),
662                        '^',
663                    );
664                    outs.extend(error_contents.lines().map(|s| s.to_string()));
665                }
666
667                for s in outs {
668                    if !self.warnings_are_errors && std::env::var("OUT_DIR").is_ok() {
669                        println!("cargo:warning={}", s)
670                    } else {
671                        eprintln!("{}", s);
672                    }
673                }
674
675                has_unallowed_missing |= self.warnings_are_errors;
676            }
677        }
678        if has_unallowed_missing {
679            fs::remove_file(outp).ok();
680            panic!();
681        }
682
683        let mod_name = match self.mod_name {
684            Some(s) => s.to_owned(),
685            None => {
686                // The user hasn't specified a module name, so we create one automatically: what we
687                // do is strip off all the filename extensions (note that it's likely that inp ends
688                // with `l.rs`, so we potentially have to strip off more than one extension) and
689                // then add `_l` to the end.
690                let mut stem = lexerp.to_str().unwrap();
691                loop {
692                    let new_stem = Path::new(stem).file_stem().unwrap().to_str().unwrap();
693                    if stem == new_stem {
694                        break;
695                    }
696                    stem = new_stem;
697                }
698                format!("{}_l", stem)
699            }
700        };
701        let mod_name = format_ident!("{}", mod_name);
702        let mut lexerdef_func_impl = {
703            let LexFlags {
704                allow_wholeline_comments,
705                dot_matches_new_line,
706                multi_line,
707                octal,
708                posix_escapes,
709                case_insensitive,
710                unicode,
711                swap_greed,
712                ignore_whitespace,
713                size_limit,
714                dfa_size_limit,
715                nest_limit,
716            } = lex_flags;
717            let allow_wholeline_comments = QuoteOption(allow_wholeline_comments);
718            let dot_matches_new_line = QuoteOption(dot_matches_new_line);
719            let multi_line = QuoteOption(multi_line);
720            let octal = QuoteOption(octal);
721            let posix_escapes = QuoteOption(posix_escapes);
722            let case_insensitive = QuoteOption(case_insensitive);
723            let unicode = QuoteOption(unicode);
724            let swap_greed = QuoteOption(swap_greed);
725            let ignore_whitespace = QuoteOption(ignore_whitespace);
726            let size_limit = QuoteOption(size_limit);
727            let dfa_size_limit = QuoteOption(dfa_size_limit);
728            let nest_limit = QuoteOption(nest_limit);
729
730            // Code gen for the lexerdef() `lex_flags` variable.
731            quote! {
732                let mut lex_flags = ::lrlex::DEFAULT_LEX_FLAGS;
733                lex_flags.allow_wholeline_comments = #allow_wholeline_comments.or(::lrlex::DEFAULT_LEX_FLAGS.allow_wholeline_comments);
734                lex_flags.dot_matches_new_line = #dot_matches_new_line.or(::lrlex::DEFAULT_LEX_FLAGS.dot_matches_new_line);
735                lex_flags.multi_line = #multi_line.or(::lrlex::DEFAULT_LEX_FLAGS.multi_line);
736                lex_flags.octal = #octal.or(::lrlex::DEFAULT_LEX_FLAGS.octal);
737                lex_flags.posix_escapes = #posix_escapes.or(::lrlex::DEFAULT_LEX_FLAGS.posix_escapes);
738                lex_flags.case_insensitive = #case_insensitive.or(::lrlex::DEFAULT_LEX_FLAGS.case_insensitive);
739                lex_flags.unicode = #unicode.or(::lrlex::DEFAULT_LEX_FLAGS.unicode);
740                lex_flags.swap_greed = #swap_greed.or(::lrlex::DEFAULT_LEX_FLAGS.swap_greed);
741                lex_flags.ignore_whitespace = #ignore_whitespace.or(::lrlex::DEFAULT_LEX_FLAGS.ignore_whitespace);
742                lex_flags.size_limit = #size_limit.or(::lrlex::DEFAULT_LEX_FLAGS.size_limit);
743                lex_flags.dfa_size_limit = #dfa_size_limit.or(::lrlex::DEFAULT_LEX_FLAGS.dfa_size_limit);
744                lex_flags.nest_limit = #nest_limit.or(::lrlex::DEFAULT_LEX_FLAGS.nest_limit);
745                let lex_flags = lex_flags;
746            }
747        };
748        {
749            let start_states = lexerdef.iter_start_states();
750            let rules = lexerdef.iter_rules().map(|r| {
751                    let tok_id = QuoteOption(r.tok_id);
752                    let n = QuoteOption(r.name().map(QuoteToString));
753                    let target_state =
754                        QuoteOption(r.target_state().map(|(x, y)| QuoteTuple((x, y))));
755                    let n_span = r.name_span();
756                    let regex = QuoteToString(&r.re_str);
757                    let start_states = r.start_states();
758                    // Code gen to construct a rule.
759                    //
760                    // We cannot `impl ToToken for Rule` because `Rule` never stores `lex_flags`,
761                    // Thus we reference the local lex_flags variable bound earlier.
762                    quote! {
763                        Rule::new(::lrlex::unstable_api::InternalPublicApi, #tok_id, #n, #n_span, #regex.to_string(),
764                                vec![#(#start_states),*], #target_state, &lex_flags).unwrap()
765                    }
766                });
767            // Code gen for `lexerdef()`s rules and the stack of `start_states`.
768            lexerdef_func_impl.append_all(quote! {
769                let start_states: Vec<StartState> = vec![#(#start_states),*];
770                let rules = vec![#(#rules),*];
771            });
772        }
773        let lexerdef_ty = match lexerkind {
774            LexerKind::LRNonStreamingLexer => {
775                quote!(::lrlex::LRNonStreamingLexerDef)
776            }
777        };
778        // Code gen for the lexerdef() return value referencing variables bound earlier.
779        lexerdef_func_impl.append_all(quote! {
780            #lexerdef_ty::from_rules(start_states, rules)
781        });
782
783        let mut token_consts = TokenStream::new();
784        if let Some(rim) = self.rule_ids_map {
785            let mut rim_sorted = Vec::from_iter(rim.iter());
786            rim_sorted.sort_by_key(|(k, _)| *k);
787            for (name, id) in rim_sorted {
788                if RE_TOKEN_ID.is_match(&name) {
789                    let tok_ident = format_ident!("N_{}", name.to_ascii_uppercase());
790                    let storaget =
791                        str::parse::<TokenStream>(type_name::<LexerTypesT::StorageT>()).unwrap();
792                    // Code gen for the constant token values.
793                    let tok_const = quote! {
794                        #[allow(dead_code)]
795                        pub const #tok_ident: #storaget = #id;
796                    };
797                    token_consts.extend(tok_const)
798                }
799            }
800        }
801        let token_consts = token_consts.into_iter();
802        let out_tokens = {
803            let lexerdef_param = str::parse::<TokenStream>(type_name::<LexerTypesT>()).unwrap();
804            let mod_vis = self.visibility;
805            // Code gen for the generated module.
806            quote! {
807                #mod_vis mod #mod_name {
808                    use ::lrlex::{LexerDef, Rule, StartState};
809                    #[allow(dead_code)]
810                    pub fn lexerdef() -> #lexerdef_ty<#lexerdef_param> {
811                        #lexerdef_func_impl
812                    }
813
814                    #(#token_consts)*
815                }
816            }
817        };
818        // Try and run a code formatter on the generated code.
819        let unformatted = out_tokens.to_string();
820        let mut outs = String::new();
821        // Record the time that this version of lrlex was built. If the source code changes and rustc
822        // forces a recompile, this will change this value, causing anything which depends on this
823        // build of lrlex to be recompiled too.
824        let timestamp = env!("VERGEN_BUILD_TIMESTAMP");
825        write!(outs, "// lrlex build time: {}\n\n", quote!(#timestamp),).ok();
826        outs.push_str(
827            &syn::parse_str(&unformatted)
828                .map(|syntax_tree| prettyplease::unparse(&syntax_tree))
829                .unwrap_or(unformatted),
830        );
831        // If the file we're about to write out already exists with the same contents, then we
832        // don't overwrite it (since that will force a recompile of the file, and relinking of the
833        // binary etc).
834        if let Ok(curs) = read_to_string(outp) {
835            if curs == outs {
836                return Ok(CTLexer {
837                    missing_from_lexer,
838                    missing_from_parser,
839                });
840            }
841        }
842        let mut f = File::create(outp)?;
843        f.write_all(outs.as_bytes())?;
844        Ok(CTLexer {
845            missing_from_lexer,
846            missing_from_parser,
847        })
848    }
849
850    /// Given the filename `a/b.l` as input, statically compile the file `src/a/b.l` into a Rust
851    /// module which can then be imported using `lrlex_mod!("a/b.l")`. This is a convenience
852    /// function around [`process_file`](struct.CTLexerBuilder.html#method.process_file) which makes
853    /// it easier to compile `.l` files stored in a project's `src/` directory: please see
854    /// [`process_file`](#method.process_file) for additional constraints and information about the
855    /// generated files.
856    #[deprecated(
857        since = "0.11.0",
858        note = "Please use lexer_in_src_dir() and build() instead"
859    )]
860    #[allow(deprecated)]
861    pub fn process_file_in_src(
862        self,
863        srcp: &str,
864    ) -> Result<(Option<HashSet<String>>, Option<HashSet<String>>), Box<dyn Error>> {
865        let mut inp = current_dir()?;
866        inp.push("src");
867        inp.push(srcp);
868        let mut outp = PathBuf::new();
869        outp.push(var("OUT_DIR").unwrap());
870        outp.push(Path::new(srcp).parent().unwrap().to_str().unwrap());
871        create_dir_all(&outp)?;
872        let mut leaf = Path::new(srcp)
873            .file_name()
874            .unwrap()
875            .to_str()
876            .unwrap()
877            .to_owned();
878        write!(leaf, ".{}", RUST_FILE_EXT).ok();
879        outp.push(leaf);
880        self.process_file(inp, outp)
881    }
882
883    /// Statically compile the `.l` file `inp` into Rust, placing the output into the file `outp`.
884    /// The latter defines a module as follows:
885    ///
886    /// ```text
887    ///    mod modname {
888    ///      pub fn lexerdef() -> LexerDef<LexerTypesT::StorageT> { ... }
889    ///
890    ///      ...
891    ///    }
892    /// ```
893    ///
894    /// where:
895    ///  * `modname` is either:
896    ///    * the module name specified [`mod_name`](#method.mod_name)
897    ///    * or, if no module name was explicitly specified, then for the file `/a/b/c.l` the
898    ///      module name is `c_l` (i.e. the file's leaf name, minus its extension, with a prefix of
899    ///      `_l`).
900    #[deprecated(
901        since = "0.11.0",
902        note = "Please use lexer_in_src_dir() and build() instead"
903    )]
904    pub fn process_file<P, Q>(
905        mut self,
906        inp: P,
907        outp: Q,
908    ) -> Result<(Option<HashSet<String>>, Option<HashSet<String>>), Box<dyn Error>>
909    where
910        P: AsRef<Path>,
911        Q: AsRef<Path>,
912    {
913        self.lexer_path = Some(inp.as_ref().to_owned());
914        self.output_path = Some(outp.as_ref().to_owned());
915        let cl = self.build()?;
916        Ok((
917            cl.missing_from_lexer().map(|x| x.to_owned()),
918            cl.missing_from_parser()
919                .map(|x| x.iter().map(|(n, _)| n.to_owned()).collect::<HashSet<_>>()),
920        ))
921    }
922
923    /// If passed false, tokens used in the grammar but not defined in the lexer will cause a
924    /// panic at lexer generation time. Defaults to false.
925    pub fn allow_missing_terms_in_lexer(mut self, allow: bool) -> Self {
926        self.allow_missing_terms_in_lexer = allow;
927        self
928    }
929
930    /// If passed false, tokens defined in the lexer but not used in the grammar will cause a
931    /// warning at lexer generation time. Defaults to false (since lexers sometimes define tokens such
932    /// as reserved words, which are intentionally not in the grammar).
933    pub fn allow_missing_tokens_in_parser(mut self, allow: bool) -> Self {
934        self.allow_missing_tokens_in_parser = allow;
935        self
936    }
937
938    /// If set to true, [CTLexerBuilder::build] will return an error if the given lexer contains
939    /// any warnings. Defaults to `true`.
940    pub fn warnings_are_errors(mut self, flag: bool) -> Self {
941        self.warnings_are_errors = flag;
942        self
943    }
944
945    /// If set to true, [CTParserBuilder::build] will print warnings to stderr, or via cargo when
946    /// running under cargo. Defaults to `true`.
947    pub fn show_warnings(mut self, flag: bool) -> Self {
948        self.show_warnings = flag;
949        self
950    }
951
952    /// Enables `// comment` style parsing according to `flag``.
953    /// When enabled comments can appear at the beginning of a line,
954    /// and regular expressions with the `/` character should be escaped via `\/`.
955    ///
956    /// The default value is `false`.
957    ///
958    /// Setting this flag will override the same flag within a `%grmtools` section.
959    pub fn allow_wholeline_comments(mut self, flag: bool) -> Self {
960        let key = "allow_wholeline_comments".to_string();
961        self.header.insert(
962            key,
963            HeaderValue(
964                Location::Other("CTLexerBuilder".to_string()),
965                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
966            ),
967        );
968        self
969    }
970
971    /// Sets the `regex::RegexBuilder` option of the same name.
972    /// The default value is `true`.
973    ///
974    /// Setting this flag will override the same flag within a `%grmtools` section.
975    pub fn dot_matches_new_line(mut self, flag: bool) -> Self {
976        let key = "dot_matches_new_line".to_string();
977        self.header.insert(
978            key,
979            HeaderValue(
980                Location::Other("CTLexerBuilder".to_string()),
981                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
982            ),
983        );
984        self
985    }
986
987    /// Sets the `regex::RegexBuilder` option of the same name.
988    /// The default value is `true`.
989    ///
990    /// Setting this flag will override the same flag within a `%grmtools` section.
991    pub fn multi_line(mut self, flag: bool) -> Self {
992        let key = "multi_line".to_string();
993        self.header.insert(
994            key,
995            HeaderValue(
996                Location::Other("CTLexerBuilder".to_string()),
997                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
998            ),
999        );
1000        self
1001    }
1002
1003    /// Enables posix lex compatible escape sequences according to `flag`.
1004    /// The default value is `false`.
1005    ///
1006    /// Setting this flag will override the same flag within a `%grmtools` section.
1007    pub fn posix_escapes(mut self, flag: bool) -> Self {
1008        let key = "posix_escapes".to_string();
1009        self.header.insert(
1010            key,
1011            HeaderValue(
1012                Location::Other("CTLexerBuilder".to_string()),
1013                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1014            ),
1015        );
1016        self
1017    }
1018
1019    /// Sets the `regex::RegexBuilder` option of the same name.
1020    /// The default value is `true`.
1021    ///
1022    /// Setting this flag will override the same flag within a `%grmtools` section.
1023    pub fn octal(mut self, flag: bool) -> Self {
1024        let key = "octal".to_string();
1025        self.header.insert(
1026            key,
1027            HeaderValue(
1028                Location::Other("CTLexerBuilder".to_string()),
1029                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1030            ),
1031        );
1032        self
1033    }
1034
1035    /// Sets the `regex::RegexBuilder` option of the same name.
1036    /// Default value is specified by regex.
1037    ///
1038    /// Setting this flag will override the same flag within a `%grmtools` section.
1039    pub fn swap_greed(mut self, flag: bool) -> Self {
1040        let key = "swap_greed".to_string();
1041        self.header.insert(
1042            key,
1043            HeaderValue(
1044                Location::Other("CTLexerBuilder".to_string()),
1045                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1046            ),
1047        );
1048        self
1049    }
1050
1051    /// Sets the `regex::RegexBuilder` option of the same name.
1052    /// Default value is specified by regex.
1053    ///
1054    /// Setting this flag will override the same flag within a `%grmtools` section.
1055    pub fn ignore_whitespace(mut self, flag: bool) -> Self {
1056        let key = "ignore_whitespace".to_string();
1057        self.header.insert(
1058            key,
1059            HeaderValue(
1060                Location::Other("CTLexerBuilder".to_string()),
1061                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1062            ),
1063        );
1064        self
1065    }
1066
1067    /// Sets the `regex::RegexBuilder` option of the same name.
1068    /// Default value is specified by regex.
1069    ///
1070    /// Setting this flag will override the same flag within a `%grmtools` section.
1071    pub fn unicode(mut self, flag: bool) -> Self {
1072        let key = "unicode".to_string();
1073        self.header.insert(
1074            key,
1075            HeaderValue(
1076                Location::Other("CTLexerBuilder".to_string()),
1077                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1078            ),
1079        );
1080        self
1081    }
1082
1083    /// Sets the `regex::RegexBuilder` option of the same name.
1084    /// Default value is specified by regex.
1085    ///
1086    /// Setting this flag will override the same flag within a `%grmtools` section.
1087    pub fn case_insensitive(mut self, flag: bool) -> Self {
1088        let key = "case_insensitive".to_string();
1089        self.header.insert(
1090            key,
1091            HeaderValue(
1092                Location::Other("CTLexerBuilder".to_string()),
1093                Value::Flag(flag, Location::Other("CTLexerBuilder".to_string())),
1094            ),
1095        );
1096        self
1097    }
1098
1099    /// Sets the `regex::RegexBuilder` option of the same name.
1100    /// Default value is specified by regex.
1101    ///
1102    /// Setting this flag will override the same flag within a `%grmtools` section.
1103    pub fn size_limit(mut self, sz: usize) -> Self {
1104        let key = "size_limit".to_string();
1105        self.header.insert(
1106            key,
1107            HeaderValue(
1108                Location::Other("CTLexerBuilder".to_string()),
1109                Value::Setting(Setting::Num(
1110                    sz as u64,
1111                    Location::Other("CTLexerBuilder".to_string()),
1112                )),
1113            ),
1114        );
1115        self
1116    }
1117
1118    /// Sets the `regex::RegexBuilder` option of the same name.
1119    /// Default value is specified by regex.
1120    ///
1121    /// Setting this flag will override the same flag within a `%grmtools` section.
1122    pub fn dfa_size_limit(mut self, sz: usize) -> Self {
1123        let key = "dfa_size_limit".to_string();
1124        self.header.insert(
1125            key,
1126            HeaderValue(
1127                Location::Other("CTLexerBuilder".to_string()),
1128                Value::Setting(Setting::Num(
1129                    sz as u64,
1130                    Location::Other("CTLexerBuilder".to_string()),
1131                )),
1132            ),
1133        );
1134        self
1135    }
1136
1137    /// Sets the `regex::RegexBuilder` option of the same name.
1138    /// Default value is specified by regex.
1139    ///
1140    /// Setting this flag will override the same flag within a `%grmtools` section.
1141    pub fn nest_limit(mut self, lim: u32) -> Self {
1142        let key = "nest_limit".to_string();
1143        self.header.insert(
1144            key,
1145            HeaderValue(
1146                Location::Other("CTLexerBuilder".to_string()),
1147                Value::Setting(Setting::Num(
1148                    lim as u64,
1149                    Location::Other("CTLexerBuilder".to_string()),
1150                )),
1151            ),
1152        );
1153        self
1154    }
1155
1156    #[cfg(test)]
1157    pub fn inspect_lexerkind(
1158        mut self,
1159        cb: Box<dyn Fn(LexerKind) -> Result<(), Box<dyn Error>>>,
1160    ) -> Self {
1161        self.inspect_lexerkind_cb = Some(cb);
1162        self
1163    }
1164}
1165
1166/// An interface to the result of [CTLexerBuilder::build()].
1167pub struct CTLexer {
1168    missing_from_lexer: Option<HashSet<String>>,
1169    missing_from_parser: Option<HashSet<(String, Span)>>,
1170}
1171
1172impl CTLexer {
1173    fn missing_from_lexer(&self) -> Option<&HashSet<String>> {
1174        self.missing_from_lexer.as_ref()
1175    }
1176
1177    fn missing_from_parser(&self) -> Option<&HashSet<(String, Span)>> {
1178        self.missing_from_parser.as_ref()
1179    }
1180}
1181
1182/// Create a Rust module named `mod_name` that can be imported with
1183/// [`lrlex_mod!(mod_name)`](crate::lrlex_mod). The module contains one `const` `StorageT` per
1184/// token in `token_map`, with the token prefixed by `T_`. For example with `StorageT` `u8`,
1185/// `mod_name` `x`, and `token_map` `HashMap{"ID": 0, "INT": 1}` the generated module will look
1186/// roughly as follows:
1187///
1188/// ```rust,ignore
1189/// mod x {
1190///   pub const T_ID: u8 = 0;
1191///   pub const T_INT: u8 = 1;
1192/// }
1193/// ```
1194///
1195/// You can optionally remap names (for example, because the parser's token names do not lead to
1196/// valid Rust identifiers) by specifying the `rename_map` `HashMap`. For example, if `token_map`
1197/// is `HashMap{"+": 0, "ID": 1}` and `rename_map` is `HashMap{"+": "PLUS"}` then the generated
1198/// module will look roughly as follows:
1199///
1200/// ```rust,ignore
1201/// mod x {
1202///   pub const T_PLUS: u8 = 0;
1203///   pub const T_ID: u8 = 1;
1204/// }
1205/// ```
1206pub fn ct_token_map<StorageT: Display + ToTokens>(
1207    mod_name: &str,
1208    token_map: impl Borrow<HashMap<String, StorageT>>,
1209    rename_map: Option<&HashMap<&str, &str>>,
1210) -> Result<(), Box<dyn Error>> {
1211    // Record the time that this version of lrlex was built. If the source code changes and rustc
1212    // forces a recompile, this will change this value, causing anything which depends on this
1213    // build of lrlex to be recompiled too.
1214    let mut outs = String::new();
1215    let timestamp = env!("VERGEN_BUILD_TIMESTAMP");
1216    let mod_ident = format_ident!("{}", mod_name);
1217    write!(outs, "// lrlex build time: {}\n\n", quote!(#timestamp),).ok();
1218    // Sort the tokens so that they're always in the same order.
1219    // This will prevent unneeded rebuilds.
1220    let mut token_map_sorted = Vec::from_iter(token_map.borrow().iter());
1221    token_map_sorted.sort_by_key(|(k, _)| *k);
1222    let tokens = &token_map_sorted
1223        .into_iter()
1224        .map(|(k, id)| {
1225            let name = match rename_map {
1226                Some(rmap) => *rmap.get(k.as_str()).unwrap_or(&k.as_str()),
1227                _ => k,
1228            };
1229            let tok_ident = format_ident!("T_{}", name.to_ascii_uppercase());
1230            let storaget = str::parse::<TokenStream>(type_name::<StorageT>()).unwrap();
1231            // Code gen for the constant token values.
1232            quote! {
1233                pub const #tok_ident: #storaget = #id;
1234            }
1235        })
1236        .collect::<Vec<_>>();
1237    // Since the formatter doesn't preserve comments and we don't want to lose build time,
1238    // just format the module contents.
1239    let unformatted = quote! {
1240        mod #mod_ident {
1241            #![allow(dead_code)]
1242            #(#tokens)*
1243        }
1244    }
1245    .to_string();
1246    let out_mod = syn::parse_str(&unformatted)
1247        .map(|syntax_tree| prettyplease::unparse(&syntax_tree))
1248        .unwrap_or(unformatted);
1249    outs.push_str(&out_mod);
1250    let mut outp = PathBuf::from(var("OUT_DIR")?);
1251    outp.push(mod_name);
1252    outp.set_extension("rs");
1253
1254    // If the file we're about to write out already exists with the same contents, then we
1255    // don't overwrite it (since that will force a recompile of the file, and relinking of the
1256    // binary etc).
1257    if let Ok(curs) = read_to_string(&outp) {
1258        if curs == outs {
1259            return Ok(());
1260        }
1261    }
1262
1263    let mut f = File::create(outp)?;
1264    f.write_all(outs.as_bytes())?;
1265    Ok(())
1266}
1267
1268/// Indents a multi-line string and trims any trailing newline.
1269/// This currently assumes that indentation on blank lines does not matter.
1270///
1271/// The algorithm used by this function is:
1272/// 1. Prefix `s` with the indentation, indenting the first line.
1273/// 2. Trim any trailing newlines.
1274/// 3. Replace all newlines with `\n{indent}`` to indent all lines after the first.
1275///
1276/// It is plausible that we should a step 4, but currently do not:
1277/// 4. Replace all `\n{indent}\n` with `\n\n`
1278fn indent(indent: &str, s: &str) -> String {
1279    format!("{indent}{}\n", s.trim_end_matches('\n')).replace('\n', &format!("\n{}", indent))
1280}
1281
1282#[cfg(test)]
1283mod test {
1284    use std::fs::File;
1285    use std::io::Write;
1286
1287    use super::{CTLexerBuilder, LexerKind};
1288    #[test]
1289    fn test_grmtools_section_lexerkind() {
1290        let lexerkinds = [
1291            "LRNonStreamingLexer",
1292            "lrnonstreaminglexer",
1293            "LexerKind::lrnonstreaminglexer",
1294            "lexerkind::LRNonStreamingLexer",
1295        ];
1296        for (i, kind) in lexerkinds.iter().enumerate() {
1297            let lex_src = format!(
1298                "
1299%grmtools{{lexerkind: {}}}
1300%%
1301. ;
1302",
1303                kind
1304            );
1305            let lex_path = format!(
1306                "{}/test_grmtools_section_lexerkind_{}.l",
1307                env!("OUT_DIR"),
1308                i
1309            );
1310            let mut l_file = File::create(lex_path.clone()).unwrap();
1311            l_file.write_all(lex_src.as_bytes()).unwrap();
1312            CTLexerBuilder::new()
1313                .output_path(format!("{}.rs", lex_path.clone()))
1314                .lexer_path(lex_path.clone())
1315                .inspect_lexerkind(Box::new(move |lexerkind| {
1316                    assert!(matches!(lexerkind, LexerKind::LRNonStreamingLexer));
1317                    Ok(())
1318                }))
1319                .build()
1320                .unwrap();
1321        }
1322    }
1323}
lrlex/ctbuilder.rs

lrlex/
ctbuilder.rs
