eth/tracers: add position field for callTracer logs (#28389)

Currently, one can use the "withLogs" parameter to include logs in the
callTracer results, which allows the user to see at which trace level
was each log emitted.
This commit adds a position field to the logs which determine
the exact ordering of a call's logs and its subcalls. This would
be useful e.g. for explorers wishing to display the flow of execution.

Co-authored-by: jsvisa <[email protected]>

Author: alvarosevilla95

eth/tracers/internal/tracetest/calltrace_test.go

@@ -47,9 +47,10 @@ type callContext struct {
 
 // callLog is the result of LOG opCode
 type callLog struct {
-	Address common.Address `json:"address"`
-	Topics  []common.Hash  `json:"topics"`
-	Data    hexutil.Bytes  `json:"data"`
+	Address  common.Address `json:"address"`
+	Topics   []common.Hash  `json:"topics"`
+	Data     hexutil.Bytes  `json:"data"`
+	Position hexutil.Uint   `json:"position"`
 }
 
 // callTrace is the result of a callTracer run.
@@ -324,7 +325,7 @@ func TestInternals(t *testing.T) {
 				byte(vm.LOG0),
 			},
 			tracer: mkTracer("callTracer", json.RawMessage(`{ "withLog": true }`)),
-			want:   `{"from":"0x000000000000000000000000000000000000feed","gas":"0x13880","gasUsed":"0x5b9e","to":"0x00000000000000000000000000000000deadbeef","input":"0x","logs":[{"address":"0x00000000000000000000000000000000deadbeef","topics":[],"data":"0x000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}],"value":"0x0","type":"CALL"}`,
+			want:   `{"from":"0x000000000000000000000000000000000000feed","gas":"0x13880","gasUsed":"0x5b9e","to":"0x00000000000000000000000000000000deadbeef","input":"0x","logs":[{"address":"0x00000000000000000000000000000000deadbeef","topics":[],"data":"0x000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","position":"0x0"}],"value":"0x0","type":"CALL"}`,
 		},
 		{
 			// Leads to OOM on the prestate tracer

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/calldata.json

@@ -95,14 +95,16 @@
             "topics": [
               "0xe1c52dc63b719ade82e8bea94cc41a0d5d28e4aaf536adb5e9cccc9ff8c1aeda"
             ],
-            "data": "0x0000000000000000000000004f5777744b500616697cb655dcb02ee6cd51deb5be96016bb57376da7a6d296e0a405ee1501778227dfa604df0a81cb1ae018598"
+            "data": "0x0000000000000000000000004f5777744b500616697cb655dcb02ee6cd51deb5be96016bb57376da7a6d296e0a405ee1501778227dfa604df0a81cb1ae018598",
+            "position": "0x0"
           },
           {
             "address": "0x200edd17f30485a8735878661960cd7a9a95733f",
             "topics": [
               "0xacbdb084c721332ac59f9b8e392196c9eb0e4932862da8eb9beaf0dad4f550da"
             ],
-            "data": "0x0000000000000000000000000000000000000000000000000000000000000000"
+            "data": "0x0000000000000000000000000000000000000000000000000000000000000000",
+            "position": "0x0"
           }
         ],
         "value": "0x8ac7230489e80000",

eth/tracers/internal/tracetest/testdata/call_tracer_withLog/delegatecall.json

@@ -257,7 +257,8 @@
               "0x0000000000000000000000003de712784baf97260455ae25fb74f574ec9c1add",
               "0x0000000000000000000000006ca7f214ab2ddbb9a8e1a1e2c8550e3164e9dba5"
             ],
-            "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac"
+            "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac",
+            "position": "0x0"
           }
         ],
         "value": "0x0",
@@ -278,7 +279,8 @@
               "0x0000000000000000000000006ca7f214ab2ddbb9a8e1a1e2c8550e3164e9dba5",
               "0x0000000000000000000000005aae5c59d642e5fd45b427df6ed478b49d55fefd"
             ],
-            "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac"
+            "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac",
+            "position": "0x0"
           }
         ],
         "value": "0x0",
@@ -307,7 +309,8 @@
                   "0x0000000000000000000000006ca7f214ab2ddbb9a8e1a1e2c8550e3164e9dba5",
                   "0x0000000000000000000000005aae5c59d642e5fd45b427df6ed478b49d55fefd"
                 ],
-                "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac"
+                "data": "0x00000000000000000000000000000000000000000000000080d29fa5cccfadac",
+                "position": "0x0"
               }
             ],
             "value": "0x0",
@@ -328,7 +331,8 @@
                   "0x0000000000000000000000005aae5c59d642e5fd45b427df6ed478b49d55fefd",
                   "0x000000000000000000000000950ca4a06c78934a148b7a3ff3ea8fc366f77a06"
                 ],
-                "data": "0x0000000000000000000000000000000000000000000000000041f50e27d56848"
+                "data": "0x0000000000000000000000000000000000000000000000000041f50e27d56848",
+                "position": "0x0"
               }
             ],
             "value": "0x0",
@@ -391,7 +395,8 @@
                   "0x0000000000000000000000006ca7f214ab2ddbb9a8e1a1e2c8550e3164e9dba5",
                   "0x0000000000000000000000003de712784baf97260455ae25fb74f574ec9c1add"
                 ],
-                "data": "0x000000000000000000000000000000000000000000000000de0b6b3a76400000"
+                "data": "0x000000000000000000000000000000000000000000000000de0b6b3a76400000",
+                "position": "0x0"
               }
             ],
             "type": "DELEGATECALL",