tracing: fix span macros with log feature

Fixes the span macro to only substitute the field expressions once when the log feature is enabled. This stops enabling the log feature causing "use of moved value" errors and other odd behaviour. # Please enter the commit message for your changes. Lines starting # with '#' will be ignored, and an empty message aborts the commit. # # On branch macros-with-log # Your branch is up to date with 'origin/macros-with-log'. # # Changes to be committed: # modified: ../tracing/src/macros.rs # # Changes not staged for commit: # modified: Cargo.toml # # Untracked files: # examples/log-move.rs #
Skepfyr · Jan 9, 2022 · bc81ef5 · bc81ef5
1 parent 874a462
commit bc81ef5
Showing 1 changed file with 32 additions and 35 deletions.
diff --git a/tracing/src/macros.rs b/tracing/src/macros.rs
@@ -32,24 +32,22 @@ macro_rules! span {
                 fields: $($fields)*
             };
             let mut interest = $crate::collect::Interest::never();
-            if $crate::level_enabled!($lvl)
-                && { interest = CALLSITE.interest(); !interest.is_never() }
-                && CALLSITE.is_enabled(interest)
-            {
-                let meta = CALLSITE.metadata();
-                // span with explicit parent
-                $crate::Span::child_of(
-                    $parent,
-                    meta,
-                    &$crate::valueset!(meta.fields(), $($fields)*),
-                )
-            } else {
-                let span = CALLSITE.disabled_span();
-                $crate::if_log_enabled! { $lvl, {
-                    span.record_all(&$crate::valueset!(CALLSITE.metadata().fields(), $($fields)*));
-                }};
-                span
-            }
+            (|value_set| {
+                if $crate::level_enabled!($lvl)
+                    && { interest = CALLSITE.interest(); !interest.is_never() }
+                    && CALLSITE.is_enabled(interest)
+                {
+                    let meta = CALLSITE.metadata();
+                    // span with explicit parent
+                    $crate::Span::child_of($parent, meta, &value_set)
+                } else {
+                    let span = CALLSITE.disabled_span();
+                    $crate::if_log_enabled! { $lvl, {
+                        span.record_all(&value_set);
+                    }};
+                    span
+                }
+            })($crate::valueset!(CALLSITE.metadata().fields(), $($fields)*))
         }
     };
     (target: $target:expr, $lvl:expr, $name:expr, $($fields:tt)*) => {
@@ -64,23 +62,22 @@ macro_rules! span {
             };
 
             let mut interest = $crate::collect::Interest::never();
-            if $crate::level_enabled!($lvl)
-                && { interest = CALLSITE.interest(); !interest.is_never() }
-                && CALLSITE.is_enabled(interest)
-            {
-                let meta = CALLSITE.metadata();
-                // span with contextual parent
-                $crate::Span::new(
-                    meta,
-                    &$crate::valueset!(meta.fields(), $($fields)*),
-                )
-            } else {
-                let span = CALLSITE.disabled_span();
-                $crate::if_log_enabled! { $lvl, {
-                    span.record_all(&$crate::valueset!(CALLSITE.metadata().fields(), $($fields)*));
-                }};
-                span
-            }
+            (|value_set| {
+                if $crate::level_enabled!($lvl)
+                    && { interest = CALLSITE.interest(); !interest.is_never() }
+                    && CALLSITE.is_enabled(interest)
+                {
+                    let meta = CALLSITE.metadata();
+                    // span with contextual parent
+                    $crate::Span::new(meta, &value_set)
+                } else {
+                    let span = CALLSITE.disabled_span();
+                    $crate::if_log_enabled! { $lvl, {
+                        span.record_all(&value_set);
+                    }};
+                    span
+                }
+            })($crate::valueset!(CALLSITE.metadata().fields(), $($fields)*))
         }
     };
     (target: $target:expr, parent: $parent:expr, $lvl:expr, $name:expr) => {