From: Derek Parker <parkerderek86@gmail.com>
Date: Wed, 28 Oct 2020 20:54:27 +0000 (+0000)
Subject: cmd/internal/obj: add prologue_end DWARF stmt for ppc64
X-Git-Tag: go1.16beta1~330
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=63fd764502e08d067293a93d6d1a566951255ce5;p=gostls13.git

cmd/internal/obj: add prologue_end DWARF stmt for ppc64

This patch adds a prologue_end statement to the DWARF information for
the ppc64 arch.

Prologue end is used by the Delve debugger in order to determine where
to set a breakpoint to avoid the stacksplit prologue.

Updates #36612

Change-Id: Ifb16c1476fe716a0bf493c5486d1d88ebe8d0253
GitHub-Last-Rev: 77a217206d529df8bf8d4ef10a5347b6ae524612
GitHub-Pull-Request: golang/go#42261
Reviewed-on: https://go-review.googlesource.com/c/go/+/266019
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
---

diff --git a/src/cmd/internal/obj/ppc64/obj9.go b/src/cmd/internal/obj/ppc64/obj9.go
index 3ab19de602..fddf552156 100644
--- a/src/cmd/internal/obj/ppc64/obj9.go
+++ b/src/cmd/internal/obj/ppc64/obj9.go
@@ -32,6 +32,7 @@ package ppc64
 import (
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
+	"cmd/internal/src"
 	"cmd/internal/sys"
 )
 
@@ -672,6 +673,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 			// save the link register and update the stack, since that code is
 			// called directly from C/C++ and can't clobber REGTMP (R31).
 			if autosize != 0 && c.cursym.Name != "runtime.racecallbackthunk" {
+				var prologueEnd *obj.Prog
 				// Save the link register and update the SP.  MOVDU is used unless
 				// the frame size is too large.  The link register must be saved
 				// even for non-empty leaf functions so that traceback works.
@@ -685,6 +687,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 					q.To.Type = obj.TYPE_REG
 					q.To.Reg = REGTMP
 
+					prologueEnd = q
+
 					q = obj.Appendp(q, c.newprog)
 					q.As = AMOVDU
 					q.Pos = p.Pos
@@ -720,6 +724,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 					q.To.Offset = int64(-autosize)
 					q.To.Reg = REGSP
 
+					prologueEnd = q
+
 					q = obj.Appendp(q, c.newprog)
 					q.As = AADD
 					q.Pos = p.Pos
@@ -730,8 +736,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
 					q.Spadj = +autosize
 
 					q = c.ctxt.EndUnsafePoint(q, c.newprog, -1)
-
 				}
+				prologueEnd.Pos = prologueEnd.Pos.WithXlogue(src.PosPrologueEnd)
 			} else if c.cursym.Func().Text.Mark&LEAF == 0 {
 				// A very few functions that do not return to their caller
 				// (e.g. gogo) are not identified as leaves but still have