1 files changed, 87 insertions, 0 deletions
diff --git a/src/cmd/link/internal/ld/stackcheck_test.go b/src/cmd/link/internal/ld/stackcheck_test.go
new file mode 100644
index 0000000..dd7e205
--- /dev/null
+++ b/src/cmd/link/internal/ld/stackcheck_test.go
@@ -0,0 +1,87 @@
+// Copyright 2022 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.
+
+package ld
+
+import (
+	"fmt"
+	"internal/testenv"
+	"os"
+	"regexp"
+	"strconv"
+	"testing"
+)
+
+// See also $GOROOT/test/nosplit.go for multi-platform edge case tests.
+
+func TestStackCheckOutput(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	t.Parallel()
+
+	cmd := testenv.Command(t, testenv.GoToolPath(t), "build", "-o", os.DevNull, "./testdata/stackcheck")
+	// The rules for computing frame sizes on all of the
+	// architectures are complicated, so just do this on amd64.
+	cmd.Env = append(os.Environ(), "GOARCH=amd64", "GOOS=linux")
+	outB, err := cmd.CombinedOutput()
+
+	if err == nil {
+		t.Fatalf("expected link to fail")
+	}
+	out := string(outB)
+
+	t.Logf("linker output:\n%s", out)
+
+	// Get expected limit.
+	limitRe := regexp.MustCompile(`nosplit stack over (\d+) byte limit`)
+	m := limitRe.FindStringSubmatch(out)
+	if m == nil {
+		t.Fatalf("no overflow errors in output")
+	}
+	limit, _ := strconv.Atoi(m[1])
+
+	wantMap := map[string]string{
+		"main.startSelf": fmt.Sprintf(
+			`main.startSelf<0>
+    grows 1008 bytes
+    %d bytes over limit
+`, 1008-limit),
+		"main.startChain": fmt.Sprintf(
+			`main.startChain<0>
+    grows 32 bytes, calls main.chain0<0>
+        grows 48 bytes, calls main.chainEnd<0>
+            grows 1008 bytes
+            %d bytes over limit
+    grows 32 bytes, calls main.chain2<0>
+        grows 80 bytes, calls main.chainEnd<0>
+            grows 1008 bytes
+            %d bytes over limit
+`, 32+48+1008-limit, 32+80+1008-limit),
+		"main.startRec": `main.startRec<0>
+    grows 8 bytes, calls main.startRec0<0>
+        grows 8 bytes, calls main.startRec<0>
+        infinite cycle
+`,
+	}
+
+	// Parse stanzas
+	stanza := regexp.MustCompile(`^(.*): nosplit stack over \d+ byte limit\n(.*\n(?: .*\n)*)`)
+	// Strip comments from cmd/go
+	out = regexp.MustCompile(`(?m)^#.*\n`).ReplaceAllString(out, "")
+	for len(out) > 0 {
+		m := stanza.FindStringSubmatch(out)
+		if m == nil {
+			t.Fatalf("unexpected output:\n%s", out)
+		}
+		out = out[len(m[0]):]
+		fn := m[1]
+		got := m[2]
+
+		want, ok := wantMap[fn]
+		if !ok {
+			t.Errorf("unexpected function: %s", fn)
+		} else if want != got {
+			t.Errorf("want:\n%sgot:\n%s", want, got)
+		}
+	}
+}