runtime: revert "traceback: include pc=0x%x for inline frames"

This reverts commit 643d816 (CL 561635).

Reason for revert: This works for telemetry but broke various other
properties of the tracebacks as well as some programs that read
tracebacks. We should figure out a solution that works for all uses,
and in the interim we should not be making telemetry work at the
cost of breaking other, existing valid uses.

See #65761 for details.

Change-Id: I467993ae778887e5bd3cca4c0fb54e9d44802ee1
Reviewed-on: https://go-review.googlesource.com/c/go/+/571797
Auto-Submit: Russ Cox <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Austin Clements <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>

src/runtime/crash_test.go

@@ -14,7 +14,6 @@ import (
 	"internal/testenv"
 	tracev2 "internal/trace/v2"
 	"io"
-	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -29,19 +28,7 @@ import (
 
 var toRemove []string
 
-const entrypointVar = "RUNTIME_TEST_ENTRYPOINT"
-
 func TestMain(m *testing.M) {
-	switch entrypoint := os.Getenv(entrypointVar); entrypoint {
-	case "crash":
-		crash()
-		panic("unreachable")
-	default:
-		log.Fatalf("invalid %s: %q", entrypointVar, entrypoint)
-	case "":
-		// fall through to normal behavior
-	}
-
 	_, coreErrBefore := os.Stat("core")
 
 	status := m.Run()

src/runtime/traceback.go

@@ -993,24 +993,12 @@ func traceback2(u *unwinder, showRuntime bool, skip, max int) (n, lastN int) {
 			}
 			print(")\n")
 			print("\t", file, ":", line)
-			// The contract between Callers and CallersFrames uses
-			// return addresses, which are +1 relative to the CALL
-			// instruction. Follow that convention.
-			pc := uf.pc + 1
-			if !iu.isInlined(uf) && pc > f.entry() {
-				// Func-relative PCs make no sense for inlined
-				// frames because there is no actual entry.
-				print(" +", hex(pc-f.entry()))
-			}
-			if gp.m != nil && gp.m.throwing >= throwTypeRuntime && gp == gp.m.curg || level >= 2 {
-				if !iu.isInlined(uf) {
-					// The stack information makes no sense for inline frames.
-					print(" fp=", hex(u.frame.fp), " sp=", hex(u.frame.sp), " pc=", hex(pc))
-				} else {
-					// The PC for an inlined frame is a special marker NOP,
-					// but crash monitoring tools may still parse the PCs
-					// and feed them to CallersFrames.
-					print(" pc=", hex(pc))
+			if !iu.isInlined(uf) {
+				if u.frame.pc > f.entry() {
+					print(" +", hex(u.frame.pc-f.entry()))
+				}
+				if gp.m != nil && gp.m.throwing >= throwTypeRuntime && gp == gp.m.curg || level >= 2 {
+					print(" fp=", hex(u.frame.fp), " sp=", hex(u.frame.sp), " pc=", hex(u.frame.pc))
 				}
 			}
 			print("\n")