From 60e1cf4d4d6f700fd9c4847be15c79a870652b9d Mon Sep 17 00:00:00 2001
From: Stephen Eckels <stevemk14ebr@gmail.com>
Date: Mon, 9 Oct 2023 13:35:29 -0400
Subject: [PATCH] Add interface method name recovery

---
 main.go            |  1 +
 main_test.go       | 31 +++++++++++++++++++++++++++++++
 objfile/objfile.go | 23 ++++++++++++++++++-----
 3 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/main.go b/main.go
index 033c870..e2003cc 100644
--- a/main.go
+++ b/main.go
@@ -268,6 +268,7 @@ restartParseWithRealTextBase:
 			extractMetadata.Types = types
 		}
 
+		// the ITabLinks did not always exist, older versions it will be NULL
 		interfaces, err := file.ParseITabLinks(extractMetadata.Version, moduleData, extractMetadata.TabMeta.PointerSize == 8, extractMetadata.TabMeta.Endianess == "LittleEndian")
 		if err == nil {
 			extractMetadata.Interfaces = interfaces
diff --git a/main_test.go b/main_test.go
index f80bd56..0878db6 100644
--- a/main_test.go
+++ b/main_test.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 	"testing"
 
 	_ "net/http/pprof"
@@ -53,6 +54,36 @@ func TestAllVersions(t *testing.T) {
 					}
 				}
 
+				if v != "15" && v != "16" {
+					found_interface := false
+					for _, typ := range data.Types {
+						if typ.Str == "io.Writer" && typ.Kind == "Interface" {
+							found_interface = true
+							if !strings.Contains(typ.Reconstructed, "Write([]uint8) (int, error)") {
+								t.Errorf("Go %s interface method name recovery failed", v)
+							}
+						}
+					}
+
+					if !found_interface {
+						t.Errorf("Go %s interface recovery failed", v)
+					}
+				} else {
+					found_interface := false
+					for _, typ := range data.Types {
+						if typ.Str == "os.FileInfo" && typ.Kind == "Interface" {
+							found_interface = true
+							if !strings.Contains(typ.Reconstructed, "IsDir() bool") {
+								t.Errorf("Go %s interface method name recovery failed", v)
+							}
+						}
+					}
+
+					if !found_interface {
+						t.Errorf("Go %s interface recovery failed", v)
+					}
+				}
+
 				if len(data.StdFunctions) == 0 {
 					t.Errorf("Go %s std functions failed on %s: %s", v, file, err)
 				}
diff --git a/objfile/objfile.go b/objfile/objfile.go
index 4541f28..44b728f 100644
--- a/objfile/objfile.go
+++ b/objfile/objfile.go
@@ -1447,10 +1447,17 @@ func (e *Entry) ParseType_impl(runtimeVersion string, moduleData *ModuleData, ty
 
 				typeAddr := decodePtrSizeBytes(imethoddata[ptrSize*2:ptrSize*3], is64bit, littleendian)
 				parsedTypesIn, _ = e.ParseType_impl(runtimeVersion, moduleData, typeAddr, is64bit, littleendian, parsedTypesIn)
+
+				name_ptr := decodePtrSizeBytes(imethoddata[0:ptrSize], is64bit, littleendian)
+				name, err := e.readRTypeName(runtimeVersion, 0, name_ptr, is64bit, littleendian)
+				if err != nil {
+					continue
+				}
+
 				methodfunc, found := parsedTypesIn.Get(typeAddr)
 				if found {
-					interfaceDef += "\nmethod" + strconv.Itoa(i) + " " + methodfunc.(Type).Str
-					cinterfaceDef += methodfunc.(Type).CStr + "method" + strconv.Itoa(i) + ";\n"
+					interfaceDef += strings.Replace(methodfunc.(Type).Str, "func", name, 1) + "\n"
+					cinterfaceDef += methodfunc.(Type).CStr + " " + name + ";\n"
 				}
 			}
 			interfaceDef += "\n}"
@@ -1513,7 +1520,7 @@ func (e *Entry) ParseType_impl(runtimeVersion string, moduleData *ModuleData, ty
 			interfaceDef := "type interface {"
 			cinterfaceDef := "struct interface {\n"
 			(*_type).CStr = "interface_"
-			if *&_type.flags&tflagNamed != 0 {
+			if _type.flags&tflagNamed != 0 {
 				interfaceDef = fmt.Sprintf("type %s interface {", _type.Str)
 				cinterfaceDef = fmt.Sprintf("struct %s_interface {\n", _type.CStr)
 				(*_type).CStr = fmt.Sprintf("%s_interface", _type.CStr)
@@ -1539,10 +1546,16 @@ func (e *Entry) ParseType_impl(runtimeVersion string, moduleData *ModuleData, ty
 				typeAddr := moduleData.Types + uint64(method.Typ)
 				parsedTypesIn, _ = e.ParseType_impl(runtimeVersion, moduleData, typeAddr, is64bit, littleendian, parsedTypesIn)
 
+				name_ptr := moduleData.Types + uint64(method.Name)
+				name, err := e.readRTypeName(runtimeVersion, 0, name_ptr, is64bit, littleendian)
+				if err != nil {
+					continue
+				}
+
 				methodfunc, found := parsedTypesIn.Get(typeAddr)
 				if found {
-					interfaceDef += "\nmethod" + strconv.Itoa(i) + " " + methodfunc.(Type).Str
-					cinterfaceDef += methodfunc.(Type).CStr + " method" + strconv.Itoa(i) + ";\n"
+					interfaceDef += strings.Replace(methodfunc.(Type).Str, "func", name, 1) + "\n"
+					cinterfaceDef += methodfunc.(Type).CStr + " " + name + ";\n"
 				}
 			}
 			interfaceDef += "\n}"