[dev.link] all: merge branch 'master' into dev.linkdev.link

Clean merge.

Change-Id: Ia7b2808bc649790198d34c226a61d9e569084dc5

1 files changed, 90 insertions, 4 deletions

diff --git a/src/debug/dwarf/open.go b/src/debug/dwarf/open.go
index 72ee64d558..617b8c56dd 100644
--- a/src/debug/dwarf/open.go
+++ b/src/debug/dwarf/open.go
@@ -7,7 +7,10 @@
 // http://dwarfstd.org/doc/dwarf-2.0.0.pdf
 package dwarf
 
-import "encoding/binary"
+import (
+	"encoding/binary"
+	"errors"
+)
 
 // Data represents the DWARF debugging information
 // loaded from an executable file (for example, an ELF or Mach-O executable).
@@ -23,9 +26,10 @@ type Data struct {
 	str      []byte
 
 	// New sections added in DWARF 5.
-	addr       []byte
+	addr       *debugAddr
 	lineStr    []byte
 	strOffsets []byte
+	rngLists   *rngLists
 
 	// parsed data
 	abbrevCache map[uint64]abbrevTable
@@ -36,6 +40,23 @@ type Data struct {
 	unit        []unit
 }
 
+// rngLists represents the contents of a debug_rnglists section (DWARFv5).
+type rngLists struct {
+	is64  bool
+	asize uint8
+	data  []byte
+	ver   uint16
+}
+
+// debugAddr represents the contents of a debug_addr section (DWARFv5).
+type debugAddr struct {
+	is64  bool
+	asize uint8
+	data  []byte
+}
+
+var errSegmentSelector = errors.New("non-zero segment_selector size not supported")
+
 // New returns a new Data object initialized from the given parameters.
 // Rather than calling this function directly, clients should typically use
 // the DWARF method of the File type of the appropriate package debug/elf,
@@ -108,14 +129,79 @@ func (d *Data) AddTypes(name string, types []byte) error {
 // so forth. This approach is used for new DWARF sections added in
 // DWARF 5 and later.
 func (d *Data) AddSection(name string, contents []byte) error {
+	var err error
 	switch name {
 	case ".debug_addr":
-		d.addr = contents
+		d.addr, err = d.parseAddrHeader(contents)
 	case ".debug_line_str":
 		d.lineStr = contents
 	case ".debug_str_offsets":
 		d.strOffsets = contents
+	case ".debug_rnglists":
+		d.rngLists, err = d.parseRngListsHeader(contents)
 	}
 	// Just ignore names that we don't yet support.
-	return nil
+	return err
+}
+
+// parseRngListsHeader reads the header of a debug_rnglists section, see
+// DWARFv5 section 7.28 (page 242).
+func (d *Data) parseRngListsHeader(bytes []byte) (*rngLists, error) {
+	rngLists := &rngLists{data: bytes}
+
+	buf := makeBuf(d, unknownFormat{}, "rnglists", 0, bytes)
+	_, rngLists.is64 = buf.unitLength()
+
+	rngLists.ver = buf.uint16() // version
+
+	rngLists.asize = buf.uint8()
+	segsize := buf.uint8()
+	if segsize != 0 {
+		return nil, errSegmentSelector
+	}
+
+	// Header fields not read: offset_entry_count, offset table
+
+	return rngLists, nil
+}
+
+func (rngLists *rngLists) version() int {
+	return int(rngLists.ver)
+}
+
+func (rngLists *rngLists) dwarf64() (bool, bool) {
+	return rngLists.is64, true
+}
+
+func (rngLists *rngLists) addrsize() int {
+	return int(rngLists.asize)
+}
+
+// parseAddrHeader reads the header of a debug_addr section, see DWARFv5
+// section 7.27 (page 241).
+func (d *Data) parseAddrHeader(bytes []byte) (*debugAddr, error) {
+	addr := &debugAddr{data: bytes}
+
+	buf := makeBuf(d, unknownFormat{}, "addr", 0, bytes)
+	_, addr.is64 = buf.unitLength()
+
+	addr.asize = buf.uint8()
+	segsize := buf.uint8()
+	if segsize != 0 {
+		return nil, errSegmentSelector
+	}
+
+	return addr, nil
+}
+
+func (addr *debugAddr) version() int {
+	return 5
+}
+
+func (addr *debugAddr) dwarf64() (bool, bool) {
+	return addr.is64, true
+}
+
+func (addr *debugAddr) addrsize() int {
+	return int(addr.asize)
 }