debug: Allow internal slice struct fields to be signed or unsigned ints.
The DWARF types of the "len" and "cap" fields of slices are changing to
signed int. Accept both when reading slices from a debugged program.
We don't want the printer's error variable set with p.errorf in
peekUintStructField or peekIntStructField while trying the two types, so
remove those calls to errorf. More specific errors are set by callers
when necessary anyway.
Change-Id: Ib38b77ee35082529f3673bb28b5096f20e2c5a18
Reviewed-on: https://go-review.googlesource.com/10008
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/ogle/program/server/print.go b/ogle/program/server/print.go
index 4b9c3c7..a1271e8 100644
--- a/ogle/program/server/print.go
+++ b/ogle/program/server/print.go
@@ -113,12 +113,10 @@
func (p *Printer) peekUintStructField(t *dwarf.StructType, addr address, fieldName string) (uint64, bool) {
f, err := getField(t, fieldName)
if err != nil {
- p.errorf("%s", err)
return 0, false
}
ut, ok := f.Type.(*dwarf.UintType)
if !ok {
- p.errorf("struct field %s is not a uint", fieldName)
return 0, false
}
return p.peekUint(addr+address(f.ByteOffset), ut.ByteSize)
@@ -128,13 +126,11 @@
// of type t at address addr. The size of the int is determined by the field.
func (p *Printer) peekIntStructField(t *dwarf.StructType, addr address, fieldName string) (int64, bool) {
f, err := getField(t, fieldName)
- if f == nil {
- p.errorf("%s", err)
+ if err != nil {
return 0, false
}
it, ok := f.Type.(*dwarf.IntType)
if !ok {
- p.errorf("struct field %s is not an int", fieldName)
return 0, false
}
return p.peekInt(addr+address(f.ByteOffset), it.ByteSize)
@@ -699,9 +695,17 @@
// Slices look like a struct with fields array *elemtype, len uint32/64, cap uint32/64.
// BUG: Slice header appears to have fields with ByteSize == 0
ptr, ok1 := p.peekPtrStructField(&typ.StructType, a, "array")
- length, ok2 := p.peekUintStructField(&typ.StructType, a, "len")
+ length, ok2 := p.peekIntStructField(&typ.StructType, a, "len")
+ if !ok2 {
+ var u uint64
+ u, ok2 = p.peekUintStructField(&typ.StructType, a, "len")
+ length = int64(u)
+ }
// Capacity is not used yet.
- _, ok3 := p.peekUintStructField(&typ.StructType, a, "cap")
+ _, ok3 := p.peekIntStructField(&typ.StructType, a, "cap")
+ if !ok3 {
+ _, ok3 = p.peekUintStructField(&typ.StructType, a, "cap")
+ }
if !ok1 || !ok2 || !ok3 {
p.errorf("couldn't read slice")
return
@@ -712,7 +716,7 @@
p.errorf("can't determine element size")
}
p.printf("%s{", typ)
- for i := uint64(0); i < length; i++ {
+ for i := int64(0); i < length; i++ {
if i != 0 {
p.printf(", ")
}
