cmd/compile: skip escape analysis diagnostics for OADDR

For most nodes (e.g., OPTRLIT, OMAKESLICE, OCONVIFACE), escape
analysis prints "escapes to heap" or "does not escape" to indicate
whether that node's allocation can be heap or stack allocated.

These messages are also emitted for OADDR, even though OADDR does not
actually allocate anything itself. Moreover, it's redundant because
escape analysis already prints "moved to heap" diagnostics when an
OADDR node like "&x" causes x to require heap allocation.

Because OADDR nodes don't allocate memory, my escape analysis rewrite
doesn't naturally emit the "escapes to heap" / "does not escape"
diagnostics for them. It's also non-trivial to replicate the exact
semantics esc.go uses for OADDR.

Since there are so many of these messages, I'm disabling them in this
CL by themselves. I modified esc.go to suppress the Warnl calls
without any other behavior changes, and then used a shell script to
automatically remove any ERROR messages mentioned by run.go in
"missing error" or "no match for" lines.

Fixes #16300.
Updates #23109.

Change-Id: I3993e2743c3ff83ccd0893f4e73b366ff8871a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/170319
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/test/escape_array.go b/test/escape_array.go
index c2c3e2c857..231186ca1f 100644
--- a/test/escape_array.go
+++ b/test/escape_array.go
@@ -27,16 +27,16 @@ func bff(a, b *string) U { // ERROR "leaking param: a to result ~r2 level=0$" "l
 func tbff1() *string {
 	a := "cat"
 	b := "dog"       // ERROR "moved to heap: b$"
-	u := bff(&a, &b) // ERROR "tbff1 &a does not escape$" "tbff1 &b does not escape$"
+	u := bff(&a, &b)
 	_ = u[0]
-	return &b // ERROR "&b escapes to heap$"
+	return &b
 }
 
 // BAD: need fine-grained analysis to track u[0] and u[1] differently.
 func tbff2() *string {
 	a := "cat"       // ERROR "moved to heap: a$"
 	b := "dog"       // ERROR "moved to heap: b$"
-	u := bff(&a, &b) // ERROR "&a escapes to heap$" "&b escapes to heap$"
+	u := bff(&a, &b)
 	_ = u[0]
 	return u[1]
 }