Anno is a file annotation toolkit that assists with aggregating annotations and presenting them in a git annotate-style sidebar view.

Annotations come from separate "producer" commands. Anno is packaged with a few such producers, but you can also write your own without needing to change Anno itself. Producers are just programs named anno-<producer-name> that follow certain input and output conventions.

Anno is still in an initial development phase, so the only installation option involves building from source. If you have Rust's cargo package manager installed, you can use the following command:

$ cargo install --git https://github.com/jryans/anno

To use Anno, you supply a file to be annotated along with one or more annotation producers you are interested in. For example, the following uses the simple lines producer which adds lines numbers:

$ anno src/main.rs -p numbers:
num |
1   | use std::{
2   |     cmp::max,
3   |     fs,
4   |     path::PathBuf,
5   |     str::{FromStr, Lines},
6   | };
7   |
8   | use anyhow::{Context, Error, Ok, Result};
9   | use clap::Parser;
10  | use duct::cmd;
...

Multiple producers can be supplied as well. The annotations from each producer are aggregated, with producer's data shown in a separate column:

$ anno src/main.rs -p debug-line-table:<path-to-debug-info> -p numbers:
...
  | 51  |     // Read the file first to check line count
x | 52  |     let target_path = cli.file.absolutize()?;
x | 53  |     let target_content = fs::read_to_string(&target_path).with_context(|| {
x | 54  |         format!(
  | 55  |             "Unable to read file to be annotated ({})",
x | 56  |             cli.file.display()
  | 57  |         )
x | 58  |     })?;
...

• Diff mode (--diff)
  Visually highlights differences between annotations from the first two producers

  

• Diff only mode (--diff-only)
  Only show lines with differences between the first two producers

Usage: -p numbers:

This producer numbers the lines of the annotated file in order, just like you might see in an editor.

Usage: -p debug-line-table:<path-to-debug-info>

This producer takes a DWARF debug info file and checks whether each source line of the file being annotated is present in the debug info's line table.

Usage: -p debug-vars-locatable:<path-to-debug-info>

This producer takes a DWARF debug info file and collects all variables which are locatable on each source line.

Usage: -p source-computation:

This producer analyses C source files and annotates source lines where some notion of "computation" occurs.

You will need to have dbgcov-cflags from dbgcov in your PATH. The CC environment variable (or cc command) will need to point to a version of cc from GCC.

Usage: -p source-vars-may-be-defined:

This producer analyses C source files and collects all variables which may be defined on each source line.

You will need to have dbgcov-cflags from dbgcov in your PATH. The CC environment variable (or cc command) will need to point to a version of cc from GCC.

Usage: -p source-vars-must-be-defined:

This producer analyses C source files and collects all variables which must be defined on each source line.

You will need to have dbgcov-cflags from dbgcov in your PATH. The CC environment variable (or cc command) will need to point to a version of cc from GCC.

Usage: -p klee-coverage:<path-to-klee-output-dir>

This produces collates all *.istats files produced by KLEE and checks whether each source line has been covered.

Producers are currently enabled via the -p option which accepts a URI-based syntax. There may be better ways to configure this... Feel free to open an issue if you have a suggestion.

• Producer only
  producer:
• Producer with data source
  producer:/path/to/data/source
• Producer with data source and additional arguments
  producer:/path/to/data/source?param=value

One small oddity of this URI syntax is that you must add a trailing : when naming only the producer. A future version of Anno may make this optional.

For each producer, Anno attempts to execute a command formed from the producer name with the prefix anno- added to it. So for the producer lines, Anno tries to run the command anno-lines.

Currently there is no way to supply the full path to a producer command, so anno-<producer> must be accessible via your PATH environment variable.

Producers receive input from Anno via various ANNO-prefixed environment variables. This is still in flux, so it's best to check the source and examples for now.

Anno currently uses a very simple annotation format. Each producer supplies their annotation data as a line of text for each line in the file being annotated. Other output formats may be added in the future.

• [ ] Add incremental output format
• [ ] Add editor integration with more complex output abilities
• [ ] Add Compiler Explorer integration