delve/pkg/proc/dwarf_expr_test.go
chainhelen f3a191cd73
pkg/proc,service: support linux/386 (#1884)
Implement debugging function for 386 on linux with reference to AMD64.
There are a few remaining problems that need to be solved in another time.

1. The stacktrace of cgo are not exactly as expected.
2. Not implement `core` for now.
3. Not implement `call` for now. Can't not find `runtime·debugCallV1` or
   similar function in $GOROOT/src/runtime/asm_386.s.

Update #20
2020-03-10 09:34:40 -07:00

326 lines
11 KiB
Go

// Tests for loading variables that have complex location expressions. They
// are only produced for optimized code (for both Go and C) therefore we can
// not get the compiler to produce them reliably enough for tests.
package proc_test
import (
"bytes"
"debug/dwarf"
"encoding/binary"
"fmt"
"go/constant"
"testing"
"unsafe"
"github.com/go-delve/delve/pkg/dwarf/dwarfbuilder"
"github.com/go-delve/delve/pkg/dwarf/godwarf"
"github.com/go-delve/delve/pkg/dwarf/op"
"github.com/go-delve/delve/pkg/proc"
"github.com/go-delve/delve/pkg/proc/linutil"
)
func ptrSizeByRuntimeArch() int {
return int(unsafe.Sizeof(uintptr(0)))
}
func fakeCFA() uint64 {
ptrSize := ptrSizeByRuntimeArch()
if ptrSize == 8 {
return 0xc420051d00
}
if ptrSize == 4 {
return 0xc4251d00
}
panic(fmt.Errorf("not support ptr size %d", ptrSize))
}
func fakeBinaryInfo(t *testing.T, dwb *dwarfbuilder.Builder) (*proc.BinaryInfo, *dwarf.Data) {
abbrev, aranges, frame, info, line, pubnames, ranges, str, loc, err := dwb.Build()
assertNoError(err, t, "dwarfbuilder.Build")
dwdata, err := dwarf.New(abbrev, aranges, frame, info, line, pubnames, ranges, str)
assertNoError(err, t, "creating dwarf")
bi := proc.NewBinaryInfo("linux", "amd64")
bi.LoadImageFromData(dwdata, frame, line, loc)
return bi, dwdata
}
// fakeMemory implements proc.MemoryReadWriter by reading from a byte slice.
// Byte 0 of "data" is at address "base".
type fakeMemory struct {
base uint64
data []byte
}
func newFakeMemory(base uint64, contents ...interface{}) *fakeMemory {
mem := &fakeMemory{base: base}
var buf bytes.Buffer
for _, x := range contents {
binary.Write(&buf, binary.LittleEndian, x)
}
mem.data = buf.Bytes()
return mem
}
func (mem *fakeMemory) ReadMemory(data []byte, addr uintptr) (int, error) {
if uint64(addr) < mem.base {
return 0, fmt.Errorf("read out of bounds %d %#x", len(data), addr)
}
start := uint64(addr) - mem.base
end := uint64(len(data)) + start
if end > uint64(len(mem.data)) {
panic(fmt.Errorf("read out of bounds %d %#x", len(data), addr))
}
copy(data, mem.data[start:end])
return len(data), nil
}
func (mem *fakeMemory) WriteMemory(uintptr, []byte) (int, error) {
return 0, fmt.Errorf("not implemented")
}
func uintExprCheck(t *testing.T, scope *proc.EvalScope, expr string, tgt uint64) {
thevar, err := scope.EvalExpression(expr, normalLoadConfig)
assertNoError(err, t, fmt.Sprintf("EvalExpression(%s)", expr))
if thevar.Unreadable != nil {
t.Errorf("variable %q unreadable: %v", expr, thevar.Unreadable)
} else {
if v, _ := constant.Uint64Val(thevar.Value); v != tgt {
t.Errorf("expected value %x got %x for %q", tgt, v, expr)
}
}
}
func dwarfExprCheck(t *testing.T, mem proc.MemoryReadWriter, regs op.DwarfRegisters, bi *proc.BinaryInfo, testCases map[string]uint16, fn *proc.Function) *proc.EvalScope {
scope := &proc.EvalScope{Location: proc.Location{PC: 0x40100, Fn: fn}, Regs: regs, Mem: mem, BinInfo: bi}
for name, value := range testCases {
uintExprCheck(t, scope, name, uint64(value))
}
return scope
}
func dwarfRegisters(bi *proc.BinaryInfo, regs *linutil.AMD64Registers) op.DwarfRegisters {
a := proc.AMD64Arch("linux")
so := bi.PCToImage(regs.PC())
dwarfRegs := a.RegistersToDwarfRegisters(so.StaticBase, regs)
dwarfRegs.CFA = int64(fakeCFA())
dwarfRegs.FrameBase = int64(fakeCFA())
return dwarfRegs
}
func TestDwarfExprRegisters(t *testing.T) {
testCases := map[string]uint16{
"a": 0x1234,
"b": 0x4321,
"c": 0x2143,
}
dwb := dwarfbuilder.New()
uint16off := dwb.AddBaseType("uint16", dwarfbuilder.DW_ATE_unsigned, 2)
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
dwb.Attr(dwarf.AttrFrameBase, dwarfbuilder.LocationBlock(op.DW_OP_call_frame_cfa))
dwb.AddVariable("a", uint16off, dwarfbuilder.LocationBlock(op.DW_OP_reg0))
dwb.AddVariable("b", uint16off, dwarfbuilder.LocationBlock(op.DW_OP_fbreg, int(8)))
dwb.AddVariable("c", uint16off, dwarfbuilder.LocationBlock(op.DW_OP_regx, int(1)))
dwb.TagClose()
bi, _ := fakeBinaryInfo(t, dwb)
mainfn := bi.LookupFunc["main.main"]
mem := newFakeMemory(fakeCFA(), uint64(0), uint64(testCases["b"]))
regs := linutil.AMD64Registers{Regs: &linutil.AMD64PtraceRegs{}}
regs.Regs.Rax = uint64(testCases["a"])
regs.Regs.Rdx = uint64(testCases["c"])
dwarfExprCheck(t, mem, dwarfRegisters(bi, &regs), bi, testCases, mainfn)
}
func TestDwarfExprComposite(t *testing.T) {
testCases := map[string]uint16{
"pair.k": 0x8765,
"pair.v": 0x5678,
"n": 42,
}
const stringVal = "this is a string"
dwb := dwarfbuilder.New()
uint16off := dwb.AddBaseType("uint16", dwarfbuilder.DW_ATE_unsigned, 2)
intoff := dwb.AddBaseType("int", dwarfbuilder.DW_ATE_signed, 8)
byteoff := dwb.AddBaseType("uint8", dwarfbuilder.DW_ATE_unsigned, 1)
byteptroff := dwb.AddPointerType("*uint8", byteoff)
pairoff := dwb.AddStructType("main.pair", 4)
dwb.Attr(godwarf.AttrGoKind, uint8(25))
dwb.AddMember("k", uint16off, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(0)))
dwb.AddMember("v", uint16off, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(2)))
dwb.TagClose()
stringoff := dwb.AddStructType("string", 16)
dwb.Attr(godwarf.AttrGoKind, uint8(24))
dwb.AddMember("str", byteptroff, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(0)))
dwb.AddMember("len", intoff, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(8)))
dwb.TagClose()
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
dwb.AddVariable("pair", pairoff, dwarfbuilder.LocationBlock(
op.DW_OP_reg2, op.DW_OP_piece, uint(2),
op.DW_OP_call_frame_cfa, op.DW_OP_consts, int(16), op.DW_OP_plus, op.DW_OP_piece, uint(2)))
dwb.AddVariable("s", stringoff, dwarfbuilder.LocationBlock(
op.DW_OP_reg1, op.DW_OP_piece, uint(8),
op.DW_OP_reg0, op.DW_OP_piece, uint(8)))
dwb.AddVariable("n", intoff, dwarfbuilder.LocationBlock(op.DW_OP_reg3))
dwb.TagClose()
bi, _ := fakeBinaryInfo(t, dwb)
mainfn := bi.LookupFunc["main.main"]
mem := newFakeMemory(fakeCFA(), uint64(0), uint64(0), uint16(testCases["pair.v"]), []byte(stringVal))
var regs linutil.AMD64Registers
regs.Regs = &linutil.AMD64PtraceRegs{}
regs.Regs.Rax = uint64(len(stringVal))
regs.Regs.Rdx = fakeCFA() + 18
regs.Regs.Rcx = uint64(testCases["pair.k"])
regs.Regs.Rbx = uint64(testCases["n"])
scope := dwarfExprCheck(t, mem, dwarfRegisters(bi, &regs), bi, testCases, mainfn)
thevar, err := scope.EvalExpression("s", normalLoadConfig)
assertNoError(err, t, fmt.Sprintf("EvalExpression(%s)", "s"))
if thevar.Unreadable != nil {
t.Errorf("variable \"s\" unreadable: %v", thevar.Unreadable)
} else {
if v := constant.StringVal(thevar.Value); v != stringVal {
t.Errorf("expected value %q got %q", stringVal, v)
}
}
}
func TestDwarfExprLoclist(t *testing.T) {
const before = 0x1234
const after = 0x4321
dwb := dwarfbuilder.New()
uint16off := dwb.AddBaseType("uint16", dwarfbuilder.DW_ATE_unsigned, 2)
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
dwb.AddVariable("a", uint16off, []dwarfbuilder.LocEntry{
{0x40100, 0x40700, dwarfbuilder.LocationBlock(op.DW_OP_call_frame_cfa)},
{0x40700, 0x41000, dwarfbuilder.LocationBlock(op.DW_OP_call_frame_cfa, op.DW_OP_consts, int(2), op.DW_OP_plus)},
})
dwb.TagClose()
bi, _ := fakeBinaryInfo(t, dwb)
mainfn := bi.LookupFunc["main.main"]
mem := newFakeMemory(fakeCFA(), uint16(before), uint16(after))
const PC = 0x40100
regs := linutil.AMD64Registers{Regs: &linutil.AMD64PtraceRegs{Rip: PC}}
scope := &proc.EvalScope{Location: proc.Location{PC: PC, Fn: mainfn}, Regs: dwarfRegisters(bi, &regs), Mem: mem, BinInfo: bi}
uintExprCheck(t, scope, "a", before)
scope.PC = 0x40800
scope.Regs.Regs[scope.Regs.PCRegNum].Uint64Val = scope.PC
uintExprCheck(t, scope, "a", after)
}
func TestIssue1419(t *testing.T) {
// trying to read a slice variable with a location list that tries to read
// from registers we don't have should not cause a panic.
dwb := dwarfbuilder.New()
uint64off := dwb.AddBaseType("uint64", dwarfbuilder.DW_ATE_unsigned, 8)
intoff := dwb.AddBaseType("int", dwarfbuilder.DW_ATE_signed, 8)
intptroff := dwb.AddPointerType("*int", intoff)
sliceoff := dwb.AddStructType("[]int", 24)
dwb.Attr(godwarf.AttrGoKind, uint8(23))
dwb.AddMember("array", intptroff, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(0)))
dwb.AddMember("len", uint64off, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(8)))
dwb.AddMember("cap", uint64off, dwarfbuilder.LocationBlock(op.DW_OP_plus_uconst, uint(16)))
dwb.TagClose()
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
dwb.AddVariable("a", sliceoff, dwarfbuilder.LocationBlock(op.DW_OP_reg2, op.DW_OP_piece, uint(8), op.DW_OP_reg2, op.DW_OP_piece, uint(8), op.DW_OP_reg2, op.DW_OP_piece, uint(8)))
dwb.TagClose()
bi, _ := fakeBinaryInfo(t, dwb)
mainfn := bi.LookupFunc["main.main"]
mem := newFakeMemory(fakeCFA())
scope := &proc.EvalScope{Location: proc.Location{PC: 0x40100, Fn: mainfn}, Regs: op.DwarfRegisters{}, Mem: mem, BinInfo: bi}
va, err := scope.EvalExpression("a", normalLoadConfig)
assertNoError(err, t, "EvalExpression(a)")
t.Logf("%#x\n", va.Addr)
t.Logf("%v", va)
if va.Unreadable == nil {
t.Fatalf("expected 'a' to be unreadable but it wasn't")
}
if va.Unreadable.Error() != "could not read 8 bytes from register 2 (size: 0)" {
t.Fatalf("wrong unreadable reason for variable 'a': %v", va.Unreadable)
}
}
func TestLocationCovers(t *testing.T) {
const before = 0x1234
const after = 0x4321
dwb := dwarfbuilder.New()
uint16off := dwb.AddBaseType("uint16", dwarfbuilder.DW_ATE_unsigned, 2)
dwb.AddCompileUnit("main", 0x0)
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
aOff := dwb.AddVariable("a", uint16off, []dwarfbuilder.LocEntry{
{0x40100, 0x40700, dwarfbuilder.LocationBlock(op.DW_OP_call_frame_cfa)},
{0x40700, 0x41000, dwarfbuilder.LocationBlock(op.DW_OP_call_frame_cfa, op.DW_OP_consts, int(2), op.DW_OP_plus)},
})
dwb.TagClose()
dwb.TagClose()
bi, dwdata := fakeBinaryInfo(t, dwb)
dwrdr := dwdata.Reader()
dwrdr.Seek(aOff)
aEntry, err := dwrdr.Next()
assertNoError(err, t, "reading 'a' entry")
ranges, err := bi.LocationCovers(aEntry, dwarf.AttrLocation)
assertNoError(err, t, "LocationCovers")
t.Logf("%x", ranges)
if fmt.Sprintf("%x", ranges) != "[[40100 40700] [40700 41000]]" {
t.Error("wrong value returned by LocationCover")
}
}
func TestIssue1636_InlineWithoutOrigin(t *testing.T) {
// Gcc (specifically GNU C++11 6.3.0) will emit DW_TAG_inlined_subroutine
// without a DW_AT_abstract_origin or a name. What is an inlined subroutine
// without a reference to an abstract origin or even a name? Regardless,
// Delve shouldn't crash.
dwb := dwarfbuilder.New()
dwb.AddCompileUnit("main", 0x0)
dwb.AddSubprogram("main.main", 0x40100, 0x41000)
dwb.TagOpen(dwarf.TagInlinedSubroutine, "")
dwb.TagClose()
dwb.TagClose()
dwb.TagClose()
fakeBinaryInfo(t, dwb)
}