refactor getSourceLocationFromVMTraceIndex to a promise

libs/remix-debug/src/solidity-decoder/internalCallTree.js

@@ -126,18 +126,19 @@ class InternalCallTree {
 
   extractSourceLocation (step) {
     return new Promise((resolve, reject) => {
-      try {
-        const address = this.traceManager.getCurrentCalledAddressAt(step)
-        try {
-          this.sourceLocationTracker.getSourceLocationFromVMTraceIndex(address, step, this.solidityProxy.contracts).then(resolve).catch((error) => {
-            return reject('InternalCallTree - Cannot retrieve sourcelocation for step ' + step + ' ' + error)
-          })
-        } catch (error) {
+      this.traceManager.getCurrentCalledAddressAt(step, (error, address) => {
+        if (!error) {
+          try {
+            this.sourceLocationTracker.getSourceLocationFromVMTraceIndex(address, step, this.solidityProxy.contracts).then(resolve).catch((error) => {
+              return reject('InternalCallTree - Cannot retrieve sourcelocation for step ' + step + ' ' + error)
+            })
+          } catch (error) {
+            return reject('InternalCallTree - Cannot retrieve address for step ' + step + ' ' + error)
+          }
+        } else {
           return reject('InternalCallTree - Cannot retrieve address for step ' + step + ' ' + error)
         }
-      } catch (error) {
-        return reject('InternalCallTree - Cannot retrieve address for step ' + step + ' ' + error)
-      }
+      })
     })
   }