x/debug: support changes to the internal representation of interfaces' types.
There are now typedefs in different places in the DWARF type data, and
the type name is now stored as a string instead of a *string. This
supports both.
Change-Id: I6f963d34a0157f76a8b3d92ef998712066806c3f
Reviewed-on: https://go-review.googlesource.com/20720
Reviewed-by: Dave Day <djd@golang.org>
diff --git a/server/print.go b/server/print.go
index 927988a..e370498 100644
--- a/server/print.go
+++ b/server/print.go
@@ -274,15 +274,11 @@
}
func (p *Printer) printInterfaceAt(t *dwarf.InterfaceType, a uint64) {
- // t should be a typedef binding a typedef binding a struct.
- tt, ok := t.TypedefType.Type.(*dwarf.TypedefType)
+ // t embeds a TypedefType, which may point to another typedef.
+ // The underlying type should be a struct.
+ st, ok := followTypedefs(&t.TypedefType).(*dwarf.StructType)
if !ok {
- p.errorf("bad interface type: not a typedef")
- return
- }
- st, ok := tt.Type.(*dwarf.StructType)
- if !ok {
- p.errorf("bad interface type: not a typedef of a struct")
+ p.errorf("bad interface type: not a struct")
return
}
p.printf("(")
@@ -315,70 +311,71 @@
p.printf("<nil>")
return
}
- // t should be a pointer to a typedef binding a struct which contains a field _type.
- // _type should be a pointer to a typedef binding a struct which contains a field _string.
- // _string is the name of the type.
- t1, ok := t.(*dwarf.PtrType)
+ // t should be a pointer to a struct containing _type, which is a pointer to a
+ // struct containing _string, which is the name of the type.
+ // Depending on the compiler version, some of these types can be typedefs, and
+ // _string may be a string or a *string.
+ t1, ok := followTypedefs(t).(*dwarf.PtrType)
if !ok {
- p.errorf("bad type")
+ p.errorf("interface's tab is not a pointer")
return
}
- t2, ok := t1.Type.(*dwarf.TypedefType)
+ t2, ok := followTypedefs(t1.Type).(*dwarf.StructType)
if !ok {
- p.errorf("bad type")
+ p.errorf("interface's tab is not a pointer to struct")
return
}
- t3, ok := t2.Type.(*dwarf.StructType)
- if !ok {
- p.errorf("bad type")
- return
- }
- typeField, err := getField(t3, "_type")
+ typeField, err := getField(t2, "_type")
if err != nil {
p.errorf("%s", err)
return
}
- t4, ok := typeField.Type.(*dwarf.PtrType)
+ t3, ok := followTypedefs(typeField.Type).(*dwarf.PtrType)
if !ok {
- p.errorf("bad type")
+ p.errorf("interface's _type is not a pointer")
return
}
- t5, ok := t4.Type.(*dwarf.TypedefType)
+ t4, ok := followTypedefs(t3.Type).(*dwarf.StructType)
if !ok {
- p.errorf("bad type")
+ p.errorf("interface's _type is not a pointer to struct")
return
}
- t6, ok := t5.Type.(*dwarf.StructType)
- if !ok {
- p.errorf("bad type")
- return
- }
- stringField, err := getField(t6, "_string")
+ stringField, err := getField(t4, "_string")
if err != nil {
p.errorf("%s", err)
return
}
- t7, ok := stringField.Type.(*dwarf.PtrType)
- if !ok {
- p.errorf("bad type")
- return
+ if t5, ok := stringField.Type.(*dwarf.PtrType); ok {
+ stringType, ok := t5.Type.(*dwarf.StringType)
+ if !ok {
+ p.errorf("interface _string is a pointer to %T, want string or *string", t5.Type)
+ return
+ }
+ typeAddr, err := p.server.peekPtrStructField(t2, a, "_type")
+ if err != nil {
+ p.errorf("reading interface type: %s", err)
+ return
+ }
+ stringAddr, err := p.server.peekPtrStructField(t4, typeAddr, "_string")
+ if err != nil {
+ p.errorf("reading interface type: %s", err)
+ return
+ }
+ p.printStringAt(stringType, stringAddr)
+ } else {
+ stringType, ok := stringField.Type.(*dwarf.StringType)
+ if !ok {
+ p.errorf("interface _string is a %T, want string or *string", stringField.Type)
+ return
+ }
+ typeAddr, err := p.server.peekPtrStructField(t2, a, "_type")
+ if err != nil {
+ p.errorf("reading interface type: %s", err)
+ return
+ }
+ stringAddr := typeAddr + uint64(stringField.ByteOffset)
+ p.printStringAt(stringType, stringAddr)
}
- stringType, ok := t7.Type.(*dwarf.StringType)
- if !ok {
- p.errorf("bad type")
- return
- }
- typeAddr, err := p.server.peekPtrStructField(t3, a, "_type")
- if err != nil {
- p.errorf("reading interface type: %s", err)
- return
- }
- stringAddr, err := p.server.peekPtrStructField(t6, typeAddr, "_string")
- if err != nil {
- p.errorf("reading interface type: %s", err)
- return
- }
- p.printStringAt(stringType, stringAddr)
}
// maxMapValuesToPrint values are printed for each map; any remaining values are
