From 1bc96169a11f34f1f0b9c885ab7716be0d615ebd Mon Sep 17 00:00:00 2001
From: Clement <clement.chigot@atos.net>
Date: Wed, 20 Feb 2019 15:34:08 -0600
Subject: [PATCH 12/24] cmd: disable DWARF with old ld on aix/ppc64

---
 src/cmd/compile/internal/ssa/stmtlines_test.go | 34 ++++++++++++++++++++++++++
 src/cmd/link/dwarf_test.go                     | 24 ++++++++++++++++++
 src/cmd/link/internal/ld/dwarf.go              | 22 +++++++++++++++++
 3 files changed, 80 insertions(+)

diff --git a/src/cmd/compile/internal/ssa/stmtlines_test.go b/src/cmd/compile/internal/ssa/stmtlines_test.go
index c71f8befd9..4a4f64a04d 100644
--- a/src/cmd/compile/internal/ssa/stmtlines_test.go
+++ b/src/cmd/compile/internal/ssa/stmtlines_test.go
@@ -1,6 +1,7 @@
 package ssa_test
 
 import (
+	"bytes"
 	"debug/dwarf"
 	"debug/elf"
 	"debug/macho"
@@ -9,7 +10,10 @@ import (
 	"internal/testenv"
 	"internal/xcoff"
 	"io"
+	"os/exec"
 	"runtime"
+	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -49,6 +53,36 @@ func TestStmtLines(t *testing.T) {
 		t.Skip("skipping on plan9; no DWARF symbol table in executables")
 	}
 
+	if runtime.GOOS == "aix" {
+		// DWARF isn't generated in Go command if ld has a version
+		// prior to 7.2.2 (cf cmd/link/internal/dwarf.go).
+		mustBeSkipped := func() bool {
+			out, err := exec.Command("ld", "-V").CombinedOutput()
+			if err != nil {
+				t.Fatalf("ld -V failed: %v", err)
+			}
+			// ld -V output is: "ld: LD X.X.X(date)"
+			out = bytes.TrimPrefix(out, []byte("ld: LD "))
+			vers := string(bytes.Split(out, []byte("("))[0])
+			subvers := strings.Split(vers, ".")
+			if v, err := strconv.Atoi(subvers[0]); err != nil || v < 7 {
+				return true
+			}
+			if v, err := strconv.Atoi(subvers[1]); err != nil || v < 2 {
+				return true
+			}
+			if v, err := strconv.Atoi(subvers[2]); err != nil || v < 2 {
+				return true
+			}
+			return false
+		}
+
+		if mustBeSkipped() {
+			t.Skip("skipping on aix; no DWARF with ld version < 7.2.2 ")
+		}
+
+	}
+
 	lines := map[Line]bool{}
 	dw, err := open(testenv.GoToolPath(t))
 	must(err)
diff --git a/src/cmd/link/dwarf_test.go b/src/cmd/link/dwarf_test.go
index 2c01456f6b..7c98c644a4 100644
--- a/src/cmd/link/dwarf_test.go
+++ b/src/cmd/link/dwarf_test.go
@@ -5,6 +5,7 @@
 package main
 
 import (
+	"bytes"
 	"cmd/internal/objfile"
 	"debug/dwarf"
 	"internal/testenv"
@@ -15,6 +16,7 @@ import (
 	"path"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 )
@@ -45,6 +47,28 @@ func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string)
 	defer os.RemoveAll(tmpDir)
 
 	for _, prog := range []string{"testprog", "testprogcgo"} {
+		if runtime.GOOS == "aix" && prog == "testprogcgo" {
+			// DWARF isn't generated if cgo is enabled and ld has a
+			// version prior to 7.2.2 (cf cmd/link/internal/dwarf.go).
+			out, err := exec.Command("ld", "-V").CombinedOutput()
+			if err != nil {
+				t.Fatalf("ld -V failed: %v", err)
+			}
+			// ld -V output is: "ld: LD X.X.X(date)"
+			out = bytes.TrimPrefix(out, []byte("ld: LD "))
+			vers := string(bytes.Split(out, []byte("("))[0])
+			subvers := strings.Split(vers, ".")
+			if v, err := strconv.Atoi(subvers[0]); err != nil || v < 7 {
+				expectDWARF = false
+			}
+			if v, err := strconv.Atoi(subvers[1]); err != nil || v < 2 {
+				expectDWARF = false
+			}
+			if v, err := strconv.Atoi(subvers[2]); err != nil || v < 2 {
+				expectDWARF = false
+			}
+
+		}
 		t.Run(prog, func(t *testing.T) {
 			exe := filepath.Join(tmpDir, prog+".exe")
 			dir := "../../runtime/testdata/" + prog
diff --git a/src/cmd/link/internal/ld/dwarf.go b/src/cmd/link/internal/ld/dwarf.go
index 93ddf503eb..710cc113bf 100644
--- a/src/cmd/link/internal/ld/dwarf.go
+++ b/src/cmd/link/internal/ld/dwarf.go
@@ -14,6 +14,7 @@
 package ld
 
 import (
+	"bytes"
 	"cmd/internal/dwarf"
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
@@ -21,7 +22,9 @@ import (
 	"cmd/link/internal/sym"
 	"fmt"
 	"log"
+	"os/exec"
 	"sort"
+	"strconv"
 	"strings"
 )
 
@@ -1699,6 +1702,25 @@ func dwarfEnabled(ctxt *Link) bool {
 		case ctxt.HeadType == objabi.Hdarwin:
 		case ctxt.HeadType == objabi.Hwindows:
 		case ctxt.HeadType == objabi.Haix:
+			// ld doesn't support DWARF with -bnoobjreorder with version
+			// prior to 7.2.2.
+			out, err := exec.Command("ld", "-V").CombinedOutput()
+			if err != nil {
+				Exitf("ld -V failed: %v", err)
+			}
+			// ld -V output is: "ld: LD X.X.X(date)"
+			out = bytes.TrimPrefix(out, []byte("ld: LD "))
+			vers := string(bytes.Split(out, []byte("("))[0])
+			subvers := strings.Split(vers, ".")
+			if v, err := strconv.Atoi(subvers[0]); err != nil || v < 7 {
+				return false
+			}
+			if v, err := strconv.Atoi(subvers[1]); err != nil || v < 2 {
+				return false
+			}
+			if v, err := strconv.Atoi(subvers[2]); err != nil || v < 2 {
+				return false
+			}
 		default:
 			return false
 		}
-- 
2.15.1