internal/trace: move maxArgs into tracev2 and validate specs

This change moves maxArgs to tracev2 and renames it MaxTimedEventArgs.
It also updates the tests to make sure the specs conform to this
requirement.

Change-Id: I7b0c888a4dfd83306a470a4c9b0f9e44fe2e7818
Reviewed-on: https://go-review.googlesource.com/c/go/+/646016
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>

diff --git a/src/internal/trace/base.go b/src/internal/trace/base.go
index 5e11c6f0498a66fc19181613692b242115d0635a..693dbc6fa68d1a6cfd6c0f7a09a91fa359979738 100644 (file)
--- a/src/internal/trace/base.go
+++ b/src/internal/trace/base.go
@@ -16,13 +16,9 @@ import (
        "internal/trace/version"
 )
 
-// maxArgs is the maximum number of arguments for "plain" events,
-// i.e. anything that could reasonably be represented as a baseEvent.
-const maxArgs = 5
-
 // timedEventArgs is an array that is able to hold the arguments for any
 // timed event.
-type timedEventArgs [maxArgs - 1]uint64
+type timedEventArgs [tracev2.MaxTimedEventArgs - 1]uint64
 
 // baseEvent is the basic unprocessed event. This serves as a common
 // fundamental data structure across.

diff --git a/src/internal/trace/tracev2/events.go b/src/internal/trace/tracev2/events.go
index c6dd162a6312a6e4d18806fd5fd127bf907059a3..2f3581ab5b7ccbc76acd6665c71e706ea0f45ae4 100644 (file)
--- a/src/internal/trace/tracev2/events.go
+++ b/src/internal/trace/tracev2/events.go
@@ -133,6 +133,9 @@ const (
 
 const NumExperimentalEvents = MaxExperimentalEvent - MaxEvent
 
+// MaxTimedEventArgs is the maximum number of arguments for timed events.
+const MaxTimedEventArgs = 5
+
 func Specs() []EventSpec {
        return specs[:]
 }

diff --git a/src/internal/trace/tracev2/events_test.go b/src/internal/trace/tracev2/events_test.go
index 1f2fbf7610a0860ff0e1a8ba08bea6c119099fec..60c4c08c34a1278acfe150fef90d9289e86aaa80 100644 (file)
--- a/src/internal/trace/tracev2/events_test.go
+++ b/src/internal/trace/tracev2/events_test.go
@@ -38,6 +38,9 @@ func TestSpecs(t *testing.T) {
                if spec.IsStack && spec.Name != "Stack" {
                        t.Errorf("%s listed as being a stack, but is not the Stack event (unsupported)", spec.Name)
                }
+               if spec.IsTimedEvent && len(spec.Args) > tracev2.MaxTimedEventArgs {
+                       t.Errorf("%s has too many timed event args: have %d, want %d at most", spec.Name, len(spec.Args), tracev2.MaxTimedEventArgs)
+               }
                if ev.Experimental() && spec.Experiment == tracev2.NoExperiment {
                        t.Errorf("experimental event %s must have an experiment", spec.Name)
                }