Add debugging for only once per-line statement.

bin/vyper-run

@@ -12,6 +12,7 @@ from vdb.eth_tester_debug_backend import (
     PyEVMDebugBackend,
     set_debug_info
 )
+import vdb.debug_computation
 from web3.providers.eth_tester import (
     EthereumTesterProvider,
 )
@@ -165,7 +166,9 @@ if __name__ == '__main__':
 
             cast_args = cast_types(args, func_abi)
 
+            setattr(vdb.debug_computation.DebugComputation, 'enable_debug', True)
             res = getattr(contract.functions, func_name)(*cast_args).call({'gas': func_abi.get('gas', 0) + 50000})
+            setattr(vdb.debug_computation.DebugComputation, 'enable_debug', False)
 
             tx_hash = getattr(contract.functions, func_name)(*cast_args).transact({'gas': func_abi.get('gas', 0) + 50000})
 

vdb/debug_computation.py

@@ -8,6 +8,7 @@ from vdb.vdb import VyperDebugCmd
 
 
 class DebugComputation(ByzantiumComputation):
+    enable_debug = False
     source_code = None
     source_map = None
 
@@ -21,6 +22,7 @@ class DebugComputation(ByzantiumComputation):
             stdin=None,
             stdout=None
         ).cmdloop()
+        return line_no
 
     @classmethod
     def get_line_no(cls, pc):
@@ -29,10 +31,12 @@ class DebugComputation(ByzantiumComputation):
             return pc_pos_map[pc][0]
 
     @classmethod
-    def is_breakpoint(cls, pc):
+    def is_breakpoint(cls, pc, continue_line_nos):
         breakpoint_lines = cls.source_map['line_number_map']['breakpoints']
         line_no = cls.get_line_no(pc)
         if line_no is not None:
+            if line_no in continue_line_nos:  # already been here, skip.
+                return False, line_no
             return line_no in breakpoint_lines, line_no
         return False, None
 
@@ -46,6 +50,7 @@ class DebugComputation(ByzantiumComputation):
                 computation.precompiles[message.code_address](computation)
                 return computation
 
+            continue_line_nos = []
             for opcode in computation.code:
                 opcode_fn = computation.get_opcode_fn(opcode)
 
@@ -57,10 +62,11 @@ class DebugComputation(ByzantiumComputation):
                     pc_to_execute,
                 )
 
-                is_breakpoint, line_no = cls.is_breakpoint(pc_to_execute)
-                if is_breakpoint:
-                    # import ipdb; ipdb.set_trace()
+                is_breakpoint, line_no = cls.is_breakpoint(pc_to_execute, continue_line_nos)
+
+                if is_breakpoint and cls.enable_debug:
                     cls.run_debugger(computation, line_no)
+                    continue_line_nos.append(line_no)
 
                 try:
                     opcode_fn(computation=computation)