EVMC tracing for interpreter

Author: chfast

libaleth-interpreter/VM.cpp

@@ -22,6 +22,9 @@
 
 namespace
 {
+evmc_trace_callback g_traceCallback = nullptr;
+evmc_tracer_context* g_traceContext = nullptr;
+
 void destroy(evmc_instance* _instance)
 {
     (void)_instance;
@@ -33,7 +36,7 @@ void delete_output(const evmc_result* result)
 }
 
 evmc_result execute(evmc_instance* _instance, evmc_context* _context, evmc_revision _rev,
-    const evmc_message* _msg, uint8_t const* _code, size_t _codeSize) noexcept
+    evmc_message const* _msg, uint8_t const* _code, size_t _codeSize) noexcept
 {
     (void)_instance;
     std::unique_ptr<dev::eth::VM> vm{new dev::eth::VM};
@@ -82,28 +85,47 @@ evmc_result execute(evmc_instance* _instance, evmc_context* _context, evmc_revis
 
     return result;
 }
+
+void setTracer(evmc_instance* /*_instance*/, evmc_trace_callback _callback,
+    evmc_tracer_context* _context) noexcept
+{
+    g_traceCallback = _callback;
+    g_traceContext = _context;
+}
 }  // namespace
 
 extern "C" evmc_instance* evmc_create_interpreter() noexcept
 {
     // TODO: Allow creating multiple instances with different configurations.
     static evmc_instance s_instance{
-        EVMC_ABI_VERSION,
-        "interpreter",
-        aleth_get_buildinfo()->project_version,
-        ::destroy,
-        ::execute,
-        nullptr,  // set_tracer
+        EVMC_ABI_VERSION, "interpreter", aleth_get_buildinfo()->project_version, ::destroy,
+        ::execute, ::setTracer,
         nullptr,  // set_option
     };
     return &s_instance;
 }
 
-
 namespace dev
 {
 namespace eth
 {
+void VM::trace() noexcept
+{
+    if (g_traceCallback)
+    {
+        auto const& metrics = c_metrics[static_cast<size_t>(m_OP)];
+        evmc_uint256be topStackItem;
+        evmc_uint256be const* pushedStackItem = nullptr;
+        if (metrics.num_stack_returned_items == 1)
+        {
+            topStackItem = toEvmC(m_SPP[0]);
+            pushedStackItem = &topStackItem;
+        }
+        g_traceCallback(g_traceContext, m_PC, EVMC_SUCCESS, m_io_gas, m_stackEnd - m_SPP,
+            pushedStackItem, m_mem.size(), 0, 0, nullptr);
+    }
+}
+
 uint64_t VM::memNeed(u256 _offset, u256 _size)
 {
     return toInt63(_size ? u512(_offset) + _size : u512(0));
@@ -397,6 +419,7 @@ void VM::interpretCases()
             updateIOGas();
 
             m_SPP[0] = (u256)*(h256 const*)(m_mem.data() + (unsigned)m_SP[0]);
+            trace();
         }
         NEXT
 
@@ -407,6 +430,7 @@ void VM::interpretCases()
             updateIOGas();
 
             *(h256*)&m_mem[(unsigned)m_SP[0]] = (h256)m_SP[1];
+            trace();
         }
         NEXT
 
@@ -1155,11 +1179,14 @@ void VM::interpretCases()
             // get val at two-byte offset into const pool and advance pc by one-byte remainder
             TRACE_OP(2, m_PC, m_OP);
             unsigned off;
-            ++m_PC;
-            off = m_code[m_PC++] << 8;
-            off |= m_code[m_PC++];
-            m_PC += m_code[m_PC];
+            uint64_t pc = m_PC;
+            ++pc;
+            off = m_code[pc++] << 8;
+            off |= m_code[pc++];
+            pc += m_code[pc];
             m_SPP[0] = m_pool[off];
+            trace();
+            m_PC = pc;
             TRACE_VAL(2, "Retrieved pooled const", m_SPP[0]);
 #else
             throwBadInstruction();
@@ -1171,9 +1198,9 @@ void VM::interpretCases()
         {
             ON_OP();
             updateIOGas();
-            ++m_PC;
-            m_SPP[0] = m_code[m_PC];
-            ++m_PC;
+            m_SPP[0] = m_code[m_PC + 1];
+            trace();
+            m_PC += 2;
         }
         CONTINUE
 
@@ -1219,6 +1246,8 @@ void VM::interpretCases()
             // bytes to handle "out of code" push data here.
             for (++m_PC; numBytes--; ++m_PC)
                 m_SPP[0] = (m_SPP[0] << 8) | m_code[m_PC];
+
+            trace();
         }
         CONTINUE
 
@@ -1347,6 +1376,7 @@ void VM::interpretCases()
 
             updateSSGas();
             updateIOGas();
+            trace();
 
             evmc_uint256be key = toEvmC(m_SP[0]);
             evmc_uint256be value = toEvmC(m_SP[1]);

libaleth-interpreter/VM.h

@@ -80,7 +80,6 @@ class VM
     void copyCode(int);
     typedef void (VM::*MemFnPtr)();
     MemFnPtr m_bounce = nullptr;
-    uint64_t m_nSteps = 0;
 
     // return bytes
     owning_bytes_ref m_output;
@@ -115,6 +114,8 @@ class VM
     uint64_t m_newMemSize = 0;
     uint64_t m_copyMemSize = 0;
 
+    void trace() noexcept;
+
     // initialize interpreter
     void initEntry();
     void optimize();

libevm/EVMC.cpp

@@ -3,6 +3,7 @@
 
 #include "EVMC.h"
 
+#include <evmc/instructions.h>
 #include <libdevcore/Log.h>
 #include <libevm/VMFactory.h>
 
@@ -21,6 +22,36 @@ EVM::EVM(evmc_instance* _instance) noexcept : m_instance(_instance)
             m_instance->set_option(m_instance, pair.first.c_str(), pair.second.c_str());
 }
 
+EVMC::EVMC(evmc_instance* _instance) : EVM(_instance)
+{
+    static const auto tracer = [](evmc_tracer_context * context, size_t code_offset,
+        evmc_status_code status_code, int64_t gas_left, size_t stack_num_items,
+        const evmc_uint256be* pushed_stack_item, size_t memory_size, size_t changed_memory_offset,
+        size_t changed_memory_size, const uint8_t* changed_memory) noexcept
+    {
+        EVMC* evmc = reinterpret_cast<EVMC*>(context);
+
+        // TODO: It might be easier to just pass instruction from VM.
+        char const* name = evmc->m_instructionNames[evmc->m_code[code_offset]];
+
+        std::cerr << "EVMC "
+                  << " " << evmc->m_step++ << " " << code_offset << " " << name << " "
+                  << status_code << " " << gas_left << " " << stack_num_items;
+
+        if (pushed_stack_item)
+            std::cerr << " +[" << fromEvmC(*pushed_stack_item) << "]";
+
+        std::cerr << " " << memory_size << "\n";
+
+        (void)changed_memory_offset;
+        (void)changed_memory_size;
+        (void)changed_memory_size;
+        (void)changed_memory;
+    };
+
+    _instance->set_tracer(_instance, tracer, reinterpret_cast<evmc_tracer_context*>(this));
+}
+
 owning_bytes_ref EVMC::exec(u256& io_gas, ExtVMFace& _ext, const OnOpFunc& _onOp)
 {
     assert(_ext.envInfo().number() >= 0);
@@ -35,8 +66,19 @@ owning_bytes_ref EVMC::exec(u256& io_gas, ExtVMFace& _ext, const OnOpFunc& _onOp
     assert(_ext.envInfo().gasLimit() <= int64max);
     assert(_ext.depth <= static_cast<size_t>(std::numeric_limits<int32_t>::max()));
 
+    m_code = bytesConstRef{&_ext.code};
+    m_step = 0;
+
+    // FIXME: EVMC revision found twice.
+    m_instructionNames = evmc_get_instruction_names_table(toRevision(_ext.evmSchedule()));
+
+
     auto gas = static_cast<int64_t>(io_gas);
+    std::cerr << "EVMC message START " << _ext.depth << " " << _ext.caller << " -> "
+              << _ext.myAddress << " gas: " << gas << "\n";
     EVM::Result r = execute(_ext, gas);
+    std::cerr << "EVMC message END   " << _ext.depth << " status: " << r.status()
+              << " gas left: " << r.gasLeft() << "\n";
 
     switch (r.status())
     {

libevm/EVMC.h

@@ -91,9 +91,14 @@ class EVM
 class EVMC : public EVM, public VMFace
 {
 public:
-    explicit EVMC(evmc_instance* _instance) : EVM(_instance) {}
+    explicit EVMC(evmc_instance* _instance);
 
     owning_bytes_ref exec(u256& io_gas, ExtVMFace& _ext, OnOpFunc const& _onOp) final;
+
+private:
+    bytesConstRef m_code;
+    int m_step = 0;
+    char const* const* m_instructionNames = nullptr;
 };
 }
 }