1 files changed, 78 insertions, 0 deletions
diff --git a/misc/cgo/test/buildid_linux.go b/misc/cgo/test/buildid_linux.go
new file mode 100644
index 0000000..84d3edb
--- /dev/null
+++ b/misc/cgo/test/buildid_linux.go
@@ -0,0 +1,78 @@
+// Copyright 2014 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 cgotest
+
+// Test that we have no more than one build ID.  In the past we used
+// to generate a separate build ID for each package using cgo, and the
+// linker concatenated them all.  We don't want that--we only want
+// one.
+
+import (
+	"bytes"
+	"debug/elf"
+	"os"
+	"testing"
+)
+
+func testBuildID(t *testing.T) {
+	f, err := elf.Open("/proc/self/exe")
+	if err != nil {
+		if os.IsNotExist(err) {
+			t.Skip("no /proc/self/exe")
+		}
+		t.Fatal("opening /proc/self/exe: ", err)
+	}
+	defer f.Close()
+
+	c := 0
+sections:
+	for i, s := range f.Sections {
+		if s.Type != elf.SHT_NOTE {
+			continue
+		}
+
+		d, err := s.Data()
+		if err != nil {
+			t.Logf("reading data of note section %d: %v", i, err)
+			continue
+		}
+
+		for len(d) > 0 {
+
+			// ELF standards differ as to the sizes in
+			// note sections.  Both the GNU linker and
+			// gold always generate 32-bit sizes, so that
+			// is what we assume here.
+
+			if len(d) < 12 {
+				t.Logf("note section %d too short (%d < 12)", i, len(d))
+				continue sections
+			}
+
+			namesz := f.ByteOrder.Uint32(d)
+			descsz := f.ByteOrder.Uint32(d[4:])
+			typ := f.ByteOrder.Uint32(d[8:])
+
+			an := (namesz + 3) &^ 3
+			ad := (descsz + 3) &^ 3
+
+			if int(12+an+ad) > len(d) {
+				t.Logf("note section %d too short for header (%d < 12 + align(%d,4) + align(%d,4))", i, len(d), namesz, descsz)
+				continue sections
+			}
+
+			// 3 == NT_GNU_BUILD_ID
+			if typ == 3 && namesz == 4 && bytes.Equal(d[12:16], []byte("GNU\000")) {
+				c++
+			}
+
+			d = d[12+an+ad:]
+		}
+	}
+
+	if c > 1 {
+		t.Errorf("found %d build ID notes", c)
+	}
+}