chore: Enable tracing

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 58 insertions, 2 deletions

diff --git a/src/bin/subplot.rs b/src/bin/subplot.rs
index 867ffb2..28dcd74 100644
--- a/src/bin/subplot.rs
+++ b/src/bin/subplot.rs
@@ -8,6 +8,7 @@ use structopt::StructOpt;
 use subplot::{
     generate_test_program, resource, template_spec, DataFile, Document, MarkupOpts, Style,
 };
+use tracing::{event, span, Level};
 
 use std::convert::TryFrom;
 use std::ffi::OsString;
@@ -140,6 +141,8 @@ impl Extract {
     }
 
     fn run(&self) -> Result<()> {
+        let span = span!(Level::TRACE, "extract");
+        let _enter = span.enter();
         let doc = cli::load_document(&self.filename, Style::default())?;
 
         let files: Vec<&DataFile> = if self.embedded.is_empty() {
@@ -194,6 +197,8 @@ impl Filter {
     }
 
     fn run(&self) -> Result<()> {
+        let span = span!(Level::TRACE, "filter");
+        let _enter = span.enter();
         let mut buffer = String::new();
         if let Some(filename) = &self.input {
             File::open(filename)?.read_to_string(&mut buffer)?;
@@ -242,6 +247,8 @@ impl Metadata {
     }
 
     fn run(&self) -> Result<()> {
+        let span = span!(Level::TRACE, "metadata");
+        let _enter = span.enter();
         let mut doc = cli::load_document(&self.filename, Style::default())?;
         let meta = cli::Metadata::try_from(&mut doc)?;
         match self.output_format {
@@ -276,6 +283,8 @@ impl Docgen {
     }
 
     fn run(&self) -> Result<()> {
+        let span = span!(Level::TRACE, "docgen");
+        let _enter = span.enter();
         let mut style = Style::default();
         if self.output.extension() == Some(&OsString::from("pdf")) {
             style.typeset_links_as_notes();
@@ -376,6 +385,8 @@ impl Codegen {
     }
 
     fn run(&self) -> Result<()> {
+        let span = span!(Level::TRACE, "codegen");
+        let _enter = span.enter();
         let mut doc = cli::load_document(&self.filename, Style::default())?;
         doc.lint()?;
         if !doc.check_named_files_exist()? {
@@ -408,7 +419,8 @@ impl Codegen {
     }
 }
 
-fn main() {
+fn real_main() {
+    event!(Level::TRACE, "Starting Subplot");
     let argparser = Toplevel::clap();
     let version = long_version().unwrap();
     let argparser = argparser.long_version(version.as_str());
@@ -416,10 +428,54 @@ fn main() {
     let args = Toplevel::from_clap(&args);
     args.handle_special_args();
     match args.run() {
-        Ok(_) => {}
+        Ok(_) => {
+            event!(Level::TRACE, "Finished successfully");
+        }
         Err(e) => {
+            event!(Level::DEBUG, error = ?e, "Failed: {:?}", e);
             eprintln!("Failure: {:?}", e);
             process::exit(1);
         }
     }
 }
+
+fn main() {
+    let filter = match tracing_subscriber::EnvFilter::try_from_env("SUBPLOT_LOG") {
+        Ok(f) => f,
+        Err(e) => {
+            if std::env::var_os("SUBPLOT_LOG").is_none() {
+                // Missing SUBPLOT_LOG, default filter should be INFO
+                tracing_subscriber::EnvFilter::new("info")
+            } else {
+                eprintln!("Unable to parse log directive from SUBPLOT_LOG: {:?}", e);
+                process::exit(1);
+            }
+        }
+    };
+    match std::env::var("SUBPLOT_TRACE_LOG").ok().as_deref() {
+        Some("") | Some("-") => {
+            let subscriber = tracing_subscriber::fmt()
+                .with_env_filter(filter)
+                .pretty()
+                .finish();
+            tracing::subscriber::with_default(subscriber, real_main);
+        }
+        Some(fname) => {
+            let curdir = std::path::Component::CurDir;
+            let location = PathBuf::from(fname);
+            let parent = location.parent().unwrap_or_else(|| curdir.as_ref());
+            let fname = location
+                .file_name()
+                .expect("No filename given in SUBPLOT_TRACE_LOG");
+            let appender = tracing_appender::rolling::never(parent, fname);
+            let (non_blocking, _guard) = tracing_appender::non_blocking(appender);
+            let subscriber = tracing_subscriber::fmt()
+                .with_writer(non_blocking)
+                .with_env_filter(filter)
+                .pretty()
+                .finish();
+            tracing::subscriber::with_default(subscriber, real_main);
+        }
+        None => real_main(),
+    }
+}