README.md

README.md

@@ -0,0 +1,44 @@
+
+# Rustc Log Viewer
+
+This is a log viewer for rustc's tracing output (in JSON form).
+It is made for when you don't yet know in advance how you want to filter your logs,
+and to analyze a large amount of ouput and filter it down to what you want to see.
+It's a TUI, and when you apply filters they get saved to disk.
+
+Filters rarely talk about the "nth log entry".
+That way they are reproducible.
+If you change something, rerun rustc, and gather logs again, the same set of filters will create a similar trace in the UI.
+That way you can compare logs.
+
+The UI shows a kind of tree view, which you can navigate with arrow keys etc.
+Only top-level logs are shown. With `Enter` you can step into a span and see the nested logs.
+Press `?` for all possible keyboard shortcuts.
+You can transform the tree in three ways:
+
+- Delete items (`alt+d`): delete all matching items. If no predicate is given, match only the current item.
+- Inline items (`alt+r`): inlining means taking items that are otherwise nested (which you normally need to navigate into) and display them at the top level.
+- Edit the printing of items (`alt+e`): WIP
+
+An explanation of how to target groups of logs can be found by typing `?`.
+
+## Gatherling logs
+
+To make it easy to gather logs, `lv` can be used as a wraper for `rustc` or `cargo` commands.
+It has built-in presets for sets of rustc crates you might care about, and to ensure logs don't get too large.
+
+For example
+
+```
+lv types x test tests/ui/sometest.rs
+lv types rustc +stage1 example.rs
+lv show
+```
+
+Use `--compiler-root` to make sure links in the tui point to the right directory. And pick a nice theme!
+
+## Integration with `t`
+
+I built a tool to manage temporary directories: <http://github.com/jdonszelmann/t-rs>.
+If you use that tool, you'll have a folder at `~/tempdirs`.
+Logviewer follows that convention: if it finds that directory, logs go there.

src/main.rs

@@ -50,6 +50,12 @@ impl ValueEnum for Theme {
     }
 }
 
+macro_rules! types_crates {
+    () => {
+        "rustc_hir_typeck,rustc_infer,rustc_next_trait_solver,rustc_middle,rustc_traits,rustc_trait_selection,rustc_type_ir,rustc_ty_utils"
+    }
+}
+
 #[derive(Subcommand, Debug)]
 enum Preset {
     /// Explore logs
@@ -64,10 +70,11 @@ enum Preset {
         theme: Theme,
     },
 
-    /// Get all the typesystem related logs
+    #[command(about = concat!("Get all the typesystem related logs: ", types_crates!()))]
     Types,
     /// Get all logs
     All,
+    /// Specific, comma-separated crates to gather logs from
     Crates {
         #[arg(short, long)]
         crates: Vec<String>,
@@ -87,7 +94,7 @@ fn default_tempdir() -> PathBuf {
 }
 
 #[derive(Parser, Debug)]
-#[command(version, about, long_about = None)]
+#[command(version, about, long_about)]
 struct Args {
     #[command(subcommand)]
     preset: Preset,
@@ -113,14 +120,12 @@ fn main() {
     let rustc_log = match preset {
         Preset::Show {
             compiler_root,
-            theme: Theme(theme)
+            theme: Theme(theme),
         } => {
             tui::run(logs_dir, compiler_root, theme);
             exit(0);
         }
-        Preset::Types => {
+        Preset::Types => types_crates!().to_string(),
-            "rustc_hir_typeck,rustc_infer,rustc_next_trait_solver,rustc_middle,rustc_traits,rustc_trait_selection,rustc_type_ir,rustc_ty_utils".to_string()
-        }
         Preset::All => "debug".to_string(),
         Preset::Crates { crates } => crates.join(",").to_string(),
     };

src/tui/mod.rs

@@ -68,7 +68,7 @@ targeting logs:
 
 either a field after `f` or the text of the current log:
     p                   ... with a prefix
-    r                   ... matching a regex
+    /                   ... matching a regex
     e                   ... equal to selected
     c                   ... containing