tracing-attributes: implement skip_all

Using `#[instrument(skip_all)]` is equivalent to `#[instrument(skip(foo,
bar..))]` for all the parameters.

tracing-attributes/src/lib.rs

@@ -166,10 +166,13 @@ use syn::{
 /// - multiple argument names can be passed to `skip`.
 /// - arguments passed to `skip` do _not_ need to implement `fmt::Debug`.
 ///
+/// You can also use `skip_all` to skip all arguments.
+///
 /// ## Examples
 ///
 /// ```
 /// # use tracing_attributes::instrument;
+/// # use std::collections::HashMap;
 /// // This type doesn't implement `fmt::Debug`!
 /// struct NonDebug;
 ///
@@ -178,6 +181,12 @@ use syn::{
 /// fn my_function(arg: usize, non_debug: NonDebug) {
 /// // ...
 /// }
+///
+/// // These arguments are huge
+/// #[instrument(skip_all)]
+/// fn my_big_data_function(large: Vec<u8>, also_large: HashMap<String, String>) {
+/// // ...
+/// }
 /// ```
 ///
 /// Skipping the `self` parameter:
@@ -257,8 +266,8 @@ use syn::{
 /// }
 /// ```
 ///
-/// This can be used in conjunction with `skip` to record only some fields of a
-/// struct:
+/// This can be used in conjunction with `skip` or `skip_all` to record only
+/// some fields of a struct:
 /// ```
 /// # use tracing_attributes::instrument;
 /// // Remember the struct with the very large `data` field from the earlier
@@ -644,7 +653,7 @@ fn gen_block(
  let quoted_fields: Vec<_> = param_names
  .iter()
  .filter(|(param, _)| {
- if args.skips.contains(param) {
+ if args.skip_all || args.skips.contains(param) {
  return false;
  }
 
@@ -754,6 +763,7 @@ struct InstrumentArgs {
  name: Option<LitStr>,
  target: Option<LitStr>,
  skips: HashSet<Ident>,
+ skip_all: bool,
  fields: Option<Fields>,
  err: bool,
  /// Errors describing any unrecognized parse inputs that we skipped.
@@ -872,8 +882,20 @@ impl Parse for InstrumentArgs {
  if !args.skips.is_empty() {
  return Err(input.error("expected only a single `skip` argument"));
  }
+ if args.skip_all {
+ return Err(input.error("expected either `skip` or `skip_all` argument"));
+ }
  let Skips(skips) = input.parse()?;
  args.skips = skips;
+ } else if lookahead.peek(kw::skip_all) {
+ if args.skip_all {
+ return Err(input.error("expected only a single `skip_all` argument"));
+ }
+ if !args.skips.is_empty() {
+ return Err(input.error("expected either `skip` or `skip_all` argument"));
+ }
+ let _ = input.parse::<kw::skip_all>()?;
+ args.skip_all = true;
  } else if lookahead.peek(kw::fields) {
  if args.fields.is_some() {
  return Err(input.error("expected only a single `fields` argument"));
@@ -1158,6 +1180,7 @@ fn param_names(pat: Pat, record_type: RecordType) -> Box<dyn Iterator<Item = (Id
 mod kw {
  syn::custom_keyword!(fields);
  syn::custom_keyword!(skip);
+ syn::custom_keyword!(skip_all);
  syn::custom_keyword!(level);
  syn::custom_keyword!(target);
  syn::custom_keyword!(name);

tracing-attributes/tests/instrument.rs

@@ -96,6 +96,9 @@ fn skip() {
  #[instrument(target = "my_target", level = "debug", skip(_arg2, _arg3))]
  fn my_fn(arg1: usize, _arg2: UnDebug, _arg3: UnDebug) {}
 
+ #[instrument(target = "my_target", level = "debug", skip_all)]
+ fn my_fn2(_arg1: usize, _arg2: UnDebug, _arg3: UnDebug) {}
+
  let span = span::mock()
  .named("my_fn")
  .at_level(Level::DEBUG)