add DWARF method to elf.File.

test both ELF and Mach-O in dwarf package.

R=r
DELTA=83  (44 added, 10 deleted, 29 changed)
OCL=34717
CL=34790

3 files changed, 41 insertions, 33 deletions

diff --git a/src/pkg/debug/dwarf/testdata/typedef.c b/src/pkg/debug/dwarf/testdata/typedef.c
index 9a46d42e0..2ceb00ced 100644
--- a/src/pkg/debug/dwarf/testdata/typedef.c
+++ b/src/pkg/debug/dwarf/testdata/typedef.c
@@ -3,7 +3,11 @@
 // license that can be found in the LICENSE file.
 
 /*
-gcc -gdwarf-2 -c typedef.c && gcc -gdwarf-2 -o typedef.elf typedef.o
+Linux ELF:
+gcc -gdwarf-2 -m64 -c typedef.c && gcc -gdwarf-2 -m64 -o typedef.elf typedef.o
+
+OS X Mach-O:
+gcc -gdwarf-2 -m64 -c typedef.c -o typedef.macho
 */
 
 typedef volatile int* t_ptr_volatile_int;
diff --git a/src/pkg/debug/dwarf/type.go b/src/pkg/debug/dwarf/type.go
index 335ef314a..09672f392 100644
--- a/src/pkg/debug/dwarf/type.go
+++ b/src/pkg/debug/dwarf/type.go
@@ -103,7 +103,7 @@ type ArrayType struct {
 	CommonType;
 	Type Type;
 	StrideBitSize int64;	// if > 0, number of bits to hold each element
-	Count int64;
+	Count int64;	// if == -1, an incomplete array, like char x[].
 }
 
 func (t *ArrayType) String() string {
@@ -111,8 +111,6 @@ func (t *ArrayType) String() string {
 }
 
 // A VoidType represents the C void type.
-// It is only used as the subtype for a pointer:
-// a FuncType that returns no value has a nil ReturnType.
 type VoidType struct {
 	CommonType;
 }
@@ -306,8 +304,8 @@ func (d *Data) Type(off Offset) (Type, os.Error) {
 	typeOf := func(e *Entry) Type {
 		toff, ok := e.Val(AttrType).(Offset);
 		if !ok {
-			err = DecodeError{"info", e.Offset, "missing type attribute"};
-			return nil;
+			// It appears that no Type means "void".
+			return new(VoidType);
 		}
 		var t Type;
 		if t, err = d.Type(toff); err != nil {
@@ -343,8 +341,7 @@ func (d *Data) Type(off Offset) (Type, os.Error) {
 			case TagSubrangeType:
 				max, ok := kid.Val(AttrUpperBound).(int64);
 				if !ok {
-					err = DecodeError{"info", kid.Offset, "missing upper bound"};
-					goto Error;
+					max = -2;	 // Count == -1, as in x[].
 				}
 				if ndim == 0 {
 					t.Count = max+1;
@@ -548,10 +545,8 @@ func (d *Data) Type(off Offset) (Type, os.Error) {
 		t := new(FuncType);
 		typ = t;
 		d.typeCache[off] = t;
-		if e.Val(AttrType) != nil {
-			if t.ReturnType = typeOf(e); err != nil {
-				goto Error;
-			}
+		if t.ReturnType = typeOf(e); err != nil {
+			goto Error;
 		}
 		t.ParamType = make([]Type, 0, 8);
 		for kid := next(); kid != nil; kid = next() {
diff --git a/src/pkg/debug/dwarf/type_test.go b/src/pkg/debug/dwarf/type_test.go
index ea7f21976..0534518cc 100644
--- a/src/pkg/debug/dwarf/type_test.go
+++ b/src/pkg/debug/dwarf/type_test.go
@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package dwarf
+package dwarf_test
 
 import (
+	. "debug/dwarf";
 	"debug/elf";
+	"debug/macho";
 	"testing";
 )
 
@@ -32,30 +34,37 @@ func elfData(t *testing.T, name string) *Data {
 	if err != nil {
 		t.Fatal(err);
 	}
-	
-	dat := func(name string) []byte {
-		s := f.Section(".debug_" + name);
-		if s == nil {
-			return nil
-		}
-		b, err := s.Data();
-		if err != nil {
-			t.Fatal(".debug_"+name+":", err);
-		}
-		return b;
-	};
-	
-	d, err := New(dat("abbrev"), nil, nil, dat("info"), nil, nil, nil, dat("str"));
+
+	d, err := f.DWARF();
 	if err != nil {
-		t.Fatal("New:", err);
+		t.Fatal(err);
 	}
-	
 	return d;
 }
 
+func machoData(t *testing.T, name string) *Data {
+	f, err := macho.Open(name);
+	if err != nil {
+		t.Fatal(err);
+	}
 
-func TestTypedefs(t *testing.T) {
-	d := elfData(t, "testdata/typedef.elf");
+	d, err := f.DWARF();
+	if err != nil {
+		t.Fatal(err);
+	}
+	return d;
+}
+
+
+func TestTypedefsELF(t *testing.T) {
+	testTypedefs(t, elfData(t, "testdata/typedef.elf"));
+}
+
+func TestTypedefsMachO(t *testing.T) {
+	testTypedefs(t, machoData(t, "testdata/typedef.macho"));
+}
+
+func testTypedefs(t *testing.T, d *Data) {
 	r := d.Reader();
 	seen := make(map[string]bool);
 	for {
@@ -78,7 +87,7 @@ func TestTypedefs(t *testing.T) {
 			} else {
 				typstr = t1.Type.String();
 			}
-			
+
 			if want, ok := typedefTests[t1.Name]; ok {
 				if _, ok := seen[t1.Name]; ok {
 					t.Errorf("multiple definitions for %s", t1.Name);
@@ -93,7 +102,7 @@ func TestTypedefs(t *testing.T) {
 			r.SkipChildren();
 		}
 	}
-	
+
 	for k := range typedefTests {
 		if _, ok := seen[k]; !ok {
 			t.Errorf("missing %s", k);