Adding upstream version 1.19.8.upstream/1.19.8upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 112 insertions, 0 deletions

diff --git a/src/cmd/link/linkbig_test.go b/src/cmd/link/linkbig_test.go
new file mode 100644
index 0000000..2551afc
--- /dev/null
+++ b/src/cmd/link/linkbig_test.go
@@ -0,0 +1,112 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This program generates a test to verify that a program can be
+// successfully linked even when there are very large text
+// sections present.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"internal/buildcfg"
+	"internal/testenv"
+	"io/ioutil"
+	"os/exec"
+	"testing"
+)
+
+func TestLargeText(t *testing.T) {
+	if testing.Short() || (buildcfg.GOARCH != "ppc64le" && buildcfg.GOARCH != "ppc64" && buildcfg.GOARCH != "arm") {
+		t.Skipf("Skipping large text section test in short mode or on %s", buildcfg.GOARCH)
+	}
+	testenv.MustHaveGoBuild(t)
+
+	var w bytes.Buffer
+	const FN = 4
+	tmpdir := t.TempDir()
+
+	if err := ioutil.WriteFile(tmpdir+"/go.mod", []byte("module big_test\n"), 0666); err != nil {
+		t.Fatal(err)
+	}
+
+	// Generate the scenario where the total amount of text exceeds the
+	// limit for the jmp/call instruction, on RISC architectures like ppc64le,
+	// which is 2^26.  When that happens the call requires special trampolines or
+	// long branches inserted by the linker where supported.
+	// Multiple .s files are generated instead of one.
+	instOnArch := map[string]string{
+		"ppc64":   "\tMOVD\tR0,R3\n",
+		"ppc64le": "\tMOVD\tR0,R3\n",
+		"arm":     "\tMOVW\tR0,R1\n",
+	}
+	inst := instOnArch[buildcfg.GOARCH]
+	for j := 0; j < FN; j++ {
+		testname := fmt.Sprintf("bigfn%d", j)
+		fmt.Fprintf(&w, "TEXT ·%s(SB),$0\n", testname)
+		for i := 0; i < 2200000; i++ {
+			fmt.Fprintf(&w, inst)
+		}
+		fmt.Fprintf(&w, "\tRET\n")
+		err := ioutil.WriteFile(tmpdir+"/"+testname+".s", w.Bytes(), 0666)
+		if err != nil {
+			t.Fatalf("can't write output: %v\n", err)
+		}
+		w.Reset()
+	}
+	fmt.Fprintf(&w, "package main\n")
+	fmt.Fprintf(&w, "\nimport (\n")
+	fmt.Fprintf(&w, "\t\"os\"\n")
+	fmt.Fprintf(&w, "\t\"fmt\"\n")
+	fmt.Fprintf(&w, ")\n\n")
+
+	for i := 0; i < FN; i++ {
+		fmt.Fprintf(&w, "func bigfn%d()\n", i)
+	}
+	fmt.Fprintf(&w, "\nfunc main() {\n")
+
+	// There are lots of dummy code generated in the .s files just to generate a lot
+	// of text. Link them in but guard their call so their code is not executed but
+	// the main part of the program can be run.
+	fmt.Fprintf(&w, "\tif os.Getenv(\"LINKTESTARG\") != \"\" {\n")
+	for i := 0; i < FN; i++ {
+		fmt.Fprintf(&w, "\t\tbigfn%d()\n", i)
+	}
+	fmt.Fprintf(&w, "\t}\n")
+	fmt.Fprintf(&w, "\tfmt.Printf(\"PASS\\n\")\n")
+	fmt.Fprintf(&w, "}")
+	err := ioutil.WriteFile(tmpdir+"/bigfn.go", w.Bytes(), 0666)
+	if err != nil {
+		t.Fatalf("can't write output: %v\n", err)
+	}
+
+	// Build and run with internal linking.
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "bigtext")
+	cmd.Dir = tmpdir
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Build failed for big text program with internal linking: %v, output: %s", err, out)
+	}
+	cmd = exec.Command("./bigtext")
+	cmd.Dir = tmpdir
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Program built with internal linking failed to run with err %v, output: %s", err, out)
+	}
+
+	// Build and run with external linking
+	cmd = exec.Command(testenv.GoToolPath(t), "build", "-o", "bigtext", "-ldflags", "-linkmode=external")
+	cmd.Dir = tmpdir
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Build failed for big text program with external linking: %v, output: %s", err, out)
+	}
+	cmd = exec.Command("./bigtext")
+	cmd.Dir = tmpdir
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Program built with external linking failed to run with err %v, output: %s", err, out)
+	}
+}