From 8e1bab85894e1e3a5d18885ab74dead85555748e Mon Sep 17 00:00:00 2001
From: rajeevgopalakrishna <rajeevgopalakrishna@gmail.com>
Date: Tue, 4 Jun 2019 16:23:23 +0530
Subject: [PATCH] Adds a new printer (WIP) to output the evm instructions of
 nodes in functions.

---
 slither/printers/all_printers.py |  1 +
 slither/printers/summary/evm.py  | 86 ++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 slither/printers/summary/evm.py

diff --git a/slither/printers/all_printers.py b/slither/printers/all_printers.py
index 3c6ad58d3..bf339f8fd 100644
--- a/slither/printers/all_printers.py
+++ b/slither/printers/all_printers.py
@@ -13,3 +13,4 @@ from .summary.variable_order import VariableOrder
 from .summary.data_depenency import DataDependency
 from .summary.modifier_calls import Modifiers
 from .summary.require_calls import RequireOrAssert
+from .summary.evm import PrinterEVM
diff --git a/slither/printers/summary/evm.py b/slither/printers/summary/evm.py
new file mode 100644
index 000000000..9dbdf3fcd
--- /dev/null
+++ b/slither/printers/summary/evm.py
@@ -0,0 +1,86 @@
+"""
+    Module printing evm mapping of the contract
+"""
+
+import logging
+try:
+    from evm_cfg_builder.cfg import CFG
+except ImportError:
+    logger.error("ERROR: in order to use evm printer, you need to install evm-cfg-builder")
+    logger.error("pip install evm-cfg-builder")
+    sys.exit(-1)
+from slither.printers.abstract_printer import AbstractPrinter
+from slither.utils.colors import blue, green, magenta
+
+class PrinterEVM(AbstractPrinter):
+
+    ARGUMENT = 'evm'
+    HELP = 'Print the evm instructions of nodes in functions'
+
+    WIKI = 'https://github.com/trailofbits/slither/wiki/Printer-documentation#evm'
+
+    def output(self, _filename):
+        """
+            _filename is not used
+            Args:
+                _filename(string)
+        """
+
+        source_to_pc_mapping = self._process_evm_cfg(self.slither)
+
+        for contract in self.slither.contracts_derived:
+            print('Contract {}'.format(contract.name))
+            contract_file = self.slither.source_code[contract.source_mapping['filename_absolute']].encode('utf-8')
+            contract_pcs = source_to_pc_mapping['mapping', contract.name]
+            print("contract_pcs: " + str(contract_pcs))
+            contract_cfg = source_to_pc_mapping['cfg', contract.name]
+            for function in contract.functions:
+                print(f'\tFunction {function.canonical_name}')
+                for node in function.nodes:
+                    print("\t\tNode: " + str(node))
+                    node_source_line = contract_file[0:node.source_mapping['start']].count("\n".encode("utf-8")) + 1
+                    print('\t\t\tEVM Instructions:')
+                    node_pcs = contract_pcs.get(node_source_line, "[]")
+                    for pc in node_pcs:
+                        print('\t\t\t\tINS: {}'.format(pc))
+            for modifier in contract.modifiers:
+                print('\tModifier {}'.format(modifier.canonical_name))
+                for node in modifier.nodes:
+                    node_source_line = contract_file[0:node.source_mapping['start']].count("\n".encode("utf-8")) + 1
+                    print('\t\tEVM Instructions:')
+                    node_pcs = contract_pcs[node_source_line]
+                    for pc in node_pcs:
+                        print('\t\t\tINS: {}'.format(pc))
+
+    def _process_evm_cfg(self, slither):
+        source_to_pc_mapping = {}
+        for contract in slither.contracts_derived:
+            contract_bytecode_runtime = slither.crytic_compile.bytecode_runtime(contract.name)
+            contract_srcmap_runtime = slither.crytic_compile.srcmap_runtime(contract.name)
+            cfg = CFG(contract_bytecode_runtime)
+            source_to_pc_mapping['cfg', contract.name] = cfg
+            source_to_pc_mapping['mapping', contract.name] = self._generate_source_to_ins_mapping(cfg.instructions,
+                                                                                 contract_srcmap_runtime, slither,
+                                                                                 contract.source_mapping['filename_absolute'])
+        return(source_to_pc_mapping)
+    
+    def _generate_source_to_ins_mapping(self, evm_instructions, srcmap_runtime, slither, filename):
+        source_to_pc_mapping = {}
+        file_source = slither.source_code[filename].encode('utf-8')
+        prev_mapping = []
+        for idx, mapping in enumerate(srcmap_runtime):
+            mapping_item = mapping.split(':')
+            mapping_item += prev_mapping[len(mapping_item):]
+            for i in range(len(mapping_item)):
+                if mapping_item[i] == '':
+                    mapping_item[i] = int(prev_mapping[i])
+            offset, length, file_id, _ = mapping_item
+            if file_id == '-1':
+                # Internal compiler-generated code snippets to be ignored
+                # See https://github.com/ethereum/solidity/issues/6119#issuecomment-467797635
+                continue
+            offset = int(offset)
+            line_number = file_source[0:offset].count("\n".encode("utf-8")) + 1
+            prev_mapping = mapping_item
+            source_to_pc_mapping.setdefault(line_number, []).append(evm_instructions[idx].pc)
+        return(source_to_pc_mapping)