Provide optional support for emulation without `apisetschema.dll` about binee HOT 12 CLOSED

diff --git a/windows/loader.go b/windows/loader.go
index d34b487..dd1bea0 100644
--- a/windows/loader.go
+++ b/windows/loader.go
@@ -1,6 +1,7 @@
 package windows
 
 import "fmt"
+import "log"
 import "os"
 import "bytes"
 import "strings"
@@ -377,6 +378,10 @@ func retrieveDllFromDisk(cur map[string]*pefile.PeFile, apiset *pefile.PeFile, s
 	// get realDll name on disk
 	// for apiset recurse through each real dll in the apisets list
 	if strings.Compare(name[:4], "api-") == 0 {
+		if apiset == nil {
+			fmt.Fprintf(os.Stderr, "error loading dll %s; unable to locate \"apisetschema.dll\"\n", name)
+			return
+		}
 		apiset_len := len(apiset.Apisets[name[0:len(name)-6]]) - 1
 		if apiset_len >= 0 {
 			realDll = apiset.Apisets[name[0:len(name)-6]][apiset_len]
@@ -757,11 +762,11 @@ func (emu *WinEmulator) initPe(pe *pefile.PeFile, path string, arch, mode int, a
 	}
 
 	// load Apisetschema dll for mapping to real dlls
-	apisetPath, err := util.SearchFile(emu.SearchPath, "apisetschema.dll")
-	if err != nil {
-		return err
+	var apiset *pefile.PeFile
+	if apisetPath, err := util.SearchFile(emu.SearchPath, "apisetschema.dll"); err == nil {
+		// only load apisetschema.dll if present.
+		apiset, _ = pefile.LoadPeFile(apisetPath)
 	}
-	apiset, _ := pefile.LoadPeFile(apisetPath)
 
 	// create the main map to hold all name/realdll mappings to actual PeFile object
 	peMap := make(map[string]*pefile.PeFile)
@@ -813,9 +818,11 @@ func (emu *WinEmulator) initPe(pe *pefile.PeFile, path string, arch, mode int, a
 	ldrEntry := emu.createLdrEntry(pe, 0)
 	emu.writeLdrEntry(ldrEntry, "Memory")
 	emu.writeLdrEntry(ldrEntry, "Initialization")
-	var lpe *pefile.PeFile
 	for i, key := range ldrList {
-		lpe = peMap[key]
+		lpe, ok := peMap[key]
+		if !ok {
+			log.Printf("unable to locate DLL %q", key)
+		}
 		ldrEntry = emu.createLdrEntry(lpe, uint64(i+1))
 		emu.writeLdrEntry(ldrEntry, "Load")
 		emu.writeLdrEntry(ldrEntry, "Memory")
diff --git a/windows/winemulator.go b/windows/winemulator.go
index 8eeb753..5194079 100644
--- a/windows/winemulator.go
+++ b/windows/winemulator.go
@@ -1,5 +1,6 @@
 package windows
 
+import "log"
 import "gopkg.in/yaml.v2"
 import "os"
 import "io/ioutil"
@@ -280,9 +281,14 @@ func New(path string, arch, mode int, args []string, verbose int, config string,
 	}
 
 	//load the PE
-	pe, _ := pefile.LoadPeFile(emu.Binary)
+	pe, err := pefile.LoadPeFile(emu.Binary)
+	if err != nil {
+		log.Println("unable to load PE file:", err)
+	}
 	err = emu.initPe(pe, path, arch, mode, args, calldllmain)
-
+	if err != nil {
+		log.Println("unable to load PE file:", err)
+	}
 	emu.Cpu = core.NewCpuManager(emu.Uc, emu.UcMode, emu.MemRegions.StackAddress, emu.MemRegions.StackSize, emu.MemRegions.HeapAddress, emu.MemRegions.HeapSize)
 	emu.Scheduler = NewScheduleManager(&emu)
 

-	emu.SearchPath = []string{"temp/", emu.Opts.Root + "windows/system32/", "c:\\Windows\\System32"}

 	var buf []byte
 	if buf, err = ioutil.ReadFile(config); err == nil {
 		_ = yaml.Unmarshal(buf, &emu.Opts)
 	}

+	emu.SearchPath = []string{"temp/", emu.Opts.Root + "windows/system32/", "c:\\Windows\\System32"}

-import "log"
-import "gopkg.in/yaml.v2"
-import "os"
-import "io/ioutil"
-import "time"
-import "github.com/carbonblack/binee/pefile"
-import "encoding/binary"
-
-//import "regexp"
-import cs "github.com/kgwinnup/gapstone"
-import uc "github.com/unicorn-engine/unicorn/bindings/go/unicorn"
-import "sort"
-import core "github.com/carbonblack/binee/core"

+import (
+	"encoding/binary"
+	"io/ioutil"
+	"log"
+	"os"
+	"sort"
+	"time"
+
+	"github.com/carbonblack/binee/core"
+	"github.com/carbonblack/binee/pefile"
+	cs "github.com/kgwinnup/gapstone"
+	uc "github.com/unicorn-engine/unicorn/bindings/go/unicorn"
+	"gopkg.in/yaml.v2"
+)