codespan_preprocessed

This is an extension for the very useful crate codespan_reporting to deal with preprocessed file through the well-knownm4 or cpp.

Using such a preprocessor allows, among a lost of things, the inclusion of many files which are identified in the bytes sequence with preprecessor directive as:

#line 42 "/my/preprocessed/file"

This directive breaks the location of the source and so should be correctly processed to make correct location for error reporting.

This is the purpose of this crate: taking a preprocessor output and managing the different underlying locations inside it.

Example

use codespan_reporting::diagnostic::Diagnostic;use codespan_reporting::term;use codespan_reporting::term::termcolor::{ColorChoice,StandardStream};use codespan_preprocessed::PreprocessedFile;fnmain(){let file = PreprocessedFile::new( unindent::unindent(r#" #line 1 "top_file" a first statement; another one #line 1 "included_file" continue... #line 5 another line the last one "#,),);let diagnostic = Diagnostic::note().with_message("this is just an example").with_labels(vec![
file.primary_label(113..117).with_message("do you see that ?"),
file.secondary_label(21..26).with_message("is it related to this ?")]);// We now set up the writer and configuration, and then finally render the// diagnostic to standard error.// (see `codespan_reporting` documention for more details)let writer = StandardStream::stderr(ColorChoice::Always);let config = codespan_reporting::term::Config::default();
term::emit(&mut writer.lock(),&config,&file,&diagnostic);}

The previous code will produce:

note: this is just an example
┌─ included_file:6:5
│
6 │ the last one
│ ^^^^ do you see that ?
│
┌─ top_file:1:3
│
1 │ a first statement;
│ ----- is it related to this ?