From eaa1a8ee3aa05963cc30c2594345fc8f75e26930 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Wed, 5 Aug 2015 21:50:02 -0700
Subject: [PATCH] Refactoring SymbolInfo/FunctionInfo/Function into
 Symbol/Function.

---
 src/xenia/cpu/backend/assembler.h             |   8 +-
 src/xenia/cpu/backend/backend.h               |   5 +
 src/xenia/cpu/backend/code_cache.h            |   4 +-
 src/xenia/cpu/backend/x64/x64_assembler.cc    |  23 ++-
 src/xenia/cpu/backend/x64/x64_assembler.h     |   5 +-
 src/xenia/cpu/backend/x64/x64_backend.cc      |   8 +-
 src/xenia/cpu/backend/x64/x64_backend.h       |   3 +
 src/xenia/cpu/backend/x64/x64_code_cache.cc   |  12 +-
 src/xenia/cpu/backend/x64/x64_code_cache.h    |   6 +-
 .../cpu/backend/x64/x64_code_cache_win.cc     |   1 +
 src/xenia/cpu/backend/x64/x64_emitter.cc      | 115 +++++++-------
 src/xenia/cpu/backend/x64/x64_emitter.h       |  13 +-
 src/xenia/cpu/backend/x64/x64_function.cc     |  12 +-
 src/xenia/cpu/backend/x64/x64_function.h      |  13 +-
 src/xenia/cpu/backend/x64/x64_sequences.cc    |  25 +--
 .../passes/constant_propagation_pass.cc       |  12 +-
 src/xenia/cpu/debug_info.cc                   |   1 +
 src/xenia/cpu/debug_info.h                    |   9 +-
 src/xenia/cpu/frontend/ppc_emit_control.cc    |  10 +-
 src/xenia/cpu/frontend/ppc_frontend.cc        |  12 +-
 src/xenia/cpu/frontend/ppc_frontend.h         |  10 +-
 src/xenia/cpu/frontend/ppc_hir_builder.cc     |  29 ++--
 src/xenia/cpu/frontend/ppc_hir_builder.h      |  14 +-
 src/xenia/cpu/frontend/ppc_scanner.cc         |  19 ++-
 src/xenia/cpu/frontend/ppc_scanner.h          |  13 +-
 src/xenia/cpu/frontend/ppc_translator.cc      |  36 +++--
 src/xenia/cpu/frontend/ppc_translator.h       |   8 +-
 .../cpu/frontend/testing/ppc_testing_main.cc  |   8 +-
 src/xenia/cpu/function.cc                     | 124 ++++++++-------
 src/xenia/cpu/function.h                      |  91 ++++++++---
 src/xenia/cpu/hir/hir_builder.cc              |  20 +--
 src/xenia/cpu/hir/hir_builder.h               |   7 +-
 src/xenia/cpu/hir/instr.h                     |   4 +-
 src/xenia/cpu/instrument.cc                   | 114 --------------
 src/xenia/cpu/instrument.h                    | 142 ------------------
 src/xenia/cpu/module.cc                       | 123 ++++++++-------
 src/xenia/cpu/module.h                        |  40 ++---
 src/xenia/cpu/processor.cc                    | 114 +++++++-------
 src/xenia/cpu/processor.h                     |  15 +-
 src/xenia/cpu/raw_module.cc                   |   7 +
 src/xenia/cpu/raw_module.h                    |   3 +
 src/xenia/cpu/stack_walker.h                  |   4 +-
 src/xenia/cpu/stack_walker_win.cc             |  22 +--
 src/xenia/cpu/symbol.h                        |  62 ++++++++
 src/xenia/cpu/symbol_info.cc                  |  55 -------
 src/xenia/cpu/symbol_info.h                   | 122 ---------------
 src/xenia/cpu/test_module.cc                  |  29 ++--
 src/xenia/cpu/test_module.h                   |   7 +-
 src/xenia/cpu/testing/util.h                  |   3 +-
 src/xenia/cpu/xex_module.cc                   | 117 ++++++++-------
 src/xenia/cpu/xex_module.h                    |   4 +-
 src/xenia/debug/debug_server.cc               |   8 +-
 src/xenia/debug/debugger.cc                   |  68 ++++-----
 src/xenia/debug/debugger.h                    |   3 +-
 54 files changed, 715 insertions(+), 1027 deletions(-)
 delete mode 100644 src/xenia/cpu/instrument.cc
 delete mode 100644 src/xenia/cpu/instrument.h
 create mode 100644 src/xenia/cpu/symbol.h
 delete mode 100644 src/xenia/cpu/symbol_info.cc
 delete mode 100644 src/xenia/cpu/symbol_info.h

diff --git a/src/xenia/cpu/backend/assembler.h b/src/xenia/cpu/backend/assembler.h
index e9312c0d7..b8854598b 100644
--- a/src/xenia/cpu/backend/assembler.h
+++ b/src/xenia/cpu/backend/assembler.h
@@ -15,8 +15,7 @@
 namespace xe {
 namespace cpu {
 class DebugInfo;
-class Function;
-class FunctionInfo;
+class GuestFunction;
 namespace hir {
 class HIRBuilder;
 }  // namespace hir
@@ -38,10 +37,9 @@ class Assembler {
 
   virtual void Reset();
 
-  virtual bool Assemble(FunctionInfo* symbol_info, hir::HIRBuilder* builder,
+  virtual bool Assemble(GuestFunction* function, hir::HIRBuilder* builder,
                         uint32_t debug_info_flags,
-                        std::unique_ptr<DebugInfo> debug_info,
-                        Function** out_function) = 0;
+                        std::unique_ptr<DebugInfo> debug_info) = 0;
 
  protected:
   Backend* backend_;
diff --git a/src/xenia/cpu/backend/backend.h b/src/xenia/cpu/backend/backend.h
index 463a2321b..90d4adf41 100644
--- a/src/xenia/cpu/backend/backend.h
+++ b/src/xenia/cpu/backend/backend.h
@@ -16,6 +16,8 @@
 
 namespace xe {
 namespace cpu {
+class GuestFunction;
+class Module;
 class Processor;
 }  // namespace cpu
 }  // namespace xe
@@ -46,6 +48,9 @@ class Backend {
 
   virtual std::unique_ptr<Assembler> CreateAssembler() = 0;
 
+  virtual std::unique_ptr<GuestFunction> CreateGuestFunction(
+      Module* module, uint32_t address) = 0;
+
  protected:
   Processor* processor_;
   MachineInfo machine_info_;
diff --git a/src/xenia/cpu/backend/code_cache.h b/src/xenia/cpu/backend/code_cache.h
index cc7949ac3..1b98757d8 100644
--- a/src/xenia/cpu/backend/code_cache.h
+++ b/src/xenia/cpu/backend/code_cache.h
@@ -12,7 +12,7 @@
 
 #include <string>
 
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/function.h"
 
 namespace xe {
 namespace cpu {
@@ -29,7 +29,7 @@ class CodeCache {
 
   // Finds a function based on the given host PC (that may be within a
   // function).
-  virtual FunctionInfo* LookupFunction(uint64_t host_pc) = 0;
+  virtual GuestFunction* LookupFunction(uint64_t host_pc) = 0;
 
   // Finds platform-specific function unwind info for the given host PC.
   virtual void* LookupUnwindInfo(uint64_t host_pc) = 0;
diff --git a/src/xenia/cpu/backend/x64/x64_assembler.cc b/src/xenia/cpu/backend/x64/x64_assembler.cc
index 4b83dbafc..abadfa2e3 100644
--- a/src/xenia/cpu/backend/x64/x64_assembler.cc
+++ b/src/xenia/cpu/backend/x64/x64_assembler.cc
@@ -66,30 +66,26 @@ void X64Assembler::Reset() {
   Assembler::Reset();
 }
 
-bool X64Assembler::Assemble(FunctionInfo* symbol_info, HIRBuilder* builder,
+bool X64Assembler::Assemble(GuestFunction* function, HIRBuilder* builder,
                             uint32_t debug_info_flags,
-                            std::unique_ptr<DebugInfo> debug_info,
-                            Function** out_function) {
+                            std::unique_ptr<DebugInfo> debug_info) {
   SCOPE_profile_cpu_f("cpu");
 
   // Reset when we leave.
   xe::make_reset_scope(this);
 
-  // Create now, and populate as we go.
-  // We may throw it away if we fail.
-  auto fn = std::make_unique<X64Function>(symbol_info);
-
   // Lower HIR -> x64.
   void* machine_code = nullptr;
   size_t code_size = 0;
-  if (!emitter_->Emit(symbol_info, builder, debug_info_flags, debug_info.get(),
-                      machine_code, code_size, fn->source_map())) {
+  if (!emitter_->Emit(function, builder, debug_info_flags, debug_info.get(),
+                      machine_code, code_size, function->source_map())) {
     return false;
   }
 
   // Stash generated machine code.
   if (debug_info_flags & DebugInfoFlags::kDebugInfoDisasmMachineCode) {
-    DumpMachineCode(machine_code, code_size, fn->source_map(), &string_buffer_);
+    DumpMachineCode(machine_code, code_size, function->source_map(),
+                    &string_buffer_);
     debug_info->set_machine_code_disasm(string_buffer_.ToString());
     string_buffer_.Reset();
   }
@@ -102,11 +98,10 @@ bool X64Assembler::Assemble(FunctionInfo* symbol_info, HIRBuilder* builder,
     }
   }
 
-  fn->set_debug_info(std::move(debug_info));
-  fn->Setup(reinterpret_cast<uint8_t*>(machine_code), code_size);
+  function->set_debug_info(std::move(debug_info));
+  static_cast<X64Function*>(function)
+      ->Setup(reinterpret_cast<uint8_t*>(machine_code), code_size);
 
-  // Pass back ownership.
-  *out_function = fn.release();
   return true;
 }
 
diff --git a/src/xenia/cpu/backend/x64/x64_assembler.h b/src/xenia/cpu/backend/x64/x64_assembler.h
index 82c6f86d7..a97d4a411 100644
--- a/src/xenia/cpu/backend/x64/x64_assembler.h
+++ b/src/xenia/cpu/backend/x64/x64_assembler.h
@@ -35,10 +35,9 @@ class X64Assembler : public Assembler {
 
   void Reset() override;
 
-  bool Assemble(FunctionInfo* symbol_info, hir::HIRBuilder* builder,
+  bool Assemble(GuestFunction* function, hir::HIRBuilder* builder,
                 uint32_t debug_info_flags,
-                std::unique_ptr<DebugInfo> debug_info,
-                Function** out_function) override;
+                std::unique_ptr<DebugInfo> debug_info) override;
 
  private:
   void DumpMachineCode(void* machine_code, size_t code_size,
diff --git a/src/xenia/cpu/backend/x64/x64_backend.cc b/src/xenia/cpu/backend/x64/x64_backend.cc
index 99c1bfa19..539e6c0bb 100644
--- a/src/xenia/cpu/backend/x64/x64_backend.cc
+++ b/src/xenia/cpu/backend/x64/x64_backend.cc
@@ -10,8 +10,9 @@
 #include "xenia/cpu/backend/x64/x64_backend.h"
 
 #include "xenia/cpu/backend/x64/x64_assembler.h"
-#include "xenia/cpu/backend/x64/x64_emitter.h"
 #include "xenia/cpu/backend/x64/x64_code_cache.h"
+#include "xenia/cpu/backend/x64/x64_emitter.h"
+#include "xenia/cpu/backend/x64/x64_function.h"
 #include "xenia/cpu/backend/x64/x64_sequences.h"
 #include "xenia/cpu/backend/x64/x64_stack_layout.h"
 #include "xenia/cpu/processor.h"
@@ -106,6 +107,11 @@ std::unique_ptr<Assembler> X64Backend::CreateAssembler() {
   return std::make_unique<X64Assembler>(this);
 }
 
+std::unique_ptr<GuestFunction> X64Backend::CreateGuestFunction(
+    Module* module, uint32_t address) {
+  return std::make_unique<X64Function>(module, address);
+}
+
 using namespace Xbyak;
 
 X64ThunkEmitter::X64ThunkEmitter(X64Backend* backend, XbyakAllocator* allocator)
diff --git a/src/xenia/cpu/backend/x64/x64_backend.h b/src/xenia/cpu/backend/x64/x64_backend.h
index 50b691935..e4b613593 100644
--- a/src/xenia/cpu/backend/x64/x64_backend.h
+++ b/src/xenia/cpu/backend/x64/x64_backend.h
@@ -56,6 +56,9 @@ class X64Backend : public Backend {
 
   std::unique_ptr<Assembler> CreateAssembler() override;
 
+  std::unique_ptr<GuestFunction> CreateGuestFunction(Module* module,
+                                                     uint32_t address) override;
+
  private:
   std::unique_ptr<X64CodeCache> code_cache_;
 
diff --git a/src/xenia/cpu/backend/x64/x64_code_cache.cc b/src/xenia/cpu/backend/x64/x64_code_cache.cc
index 8fd5eda51..e94561dd4 100644
--- a/src/xenia/cpu/backend/x64/x64_code_cache.cc
+++ b/src/xenia/cpu/backend/x64/x64_code_cache.cc
@@ -17,6 +17,7 @@
 #include "xenia/base/logging.h"
 #include "xenia/base/math.h"
 #include "xenia/base/memory.h"
+#include "xenia/cpu/function.h"
 
 namespace xe {
 namespace cpu {
@@ -120,7 +121,7 @@ void* X64CodeCache::PlaceHostCode(uint32_t guest_address, void* machine_code,
 
 void* X64CodeCache::PlaceGuestCode(uint32_t guest_address, void* machine_code,
                                    size_t code_size, size_t stack_size,
-                                   FunctionInfo* function_info) {
+                                   GuestFunction* function_info) {
   // Hold a lock while we bump the pointers up. This is important as the
   // unwind table requires entries AND code to be sorted in order.
   size_t low_mark;
@@ -220,15 +221,15 @@ uint32_t X64CodeCache::PlaceData(const void* data, size_t length) {
   return uint32_t(uintptr_t(data_address));
 }
 
-FunctionInfo* X64CodeCache::LookupFunction(uint64_t host_pc) {
+GuestFunction* X64CodeCache::LookupFunction(uint64_t host_pc) {
   uint32_t key = uint32_t(host_pc - kGeneratedCodeBase);
   void* fn_entry = std::bsearch(
       &key, generated_code_map_.data(), generated_code_map_.size() + 1,
-      sizeof(std::pair<uint32_t, FunctionInfo*>),
+      sizeof(std::pair<uint32_t, Function*>),
       [](const void* key_ptr, const void* element_ptr) {
         auto key = *reinterpret_cast<const uint32_t*>(key_ptr);
         auto element =
-            reinterpret_cast<const std::pair<uint64_t, FunctionInfo*>*>(
+            reinterpret_cast<const std::pair<uint64_t, GuestFunction*>*>(
                 element_ptr);
         if (key < (element->first >> 32)) {
           return -1;
@@ -239,7 +240,8 @@ FunctionInfo* X64CodeCache::LookupFunction(uint64_t host_pc) {
         }
       });
   if (fn_entry) {
-    return reinterpret_cast<const std::pair<uint64_t, FunctionInfo*>*>(fn_entry)
+    return reinterpret_cast<const std::pair<uint64_t, GuestFunction*>*>(
+               fn_entry)
         ->second;
   } else {
     return nullptr;
diff --git a/src/xenia/cpu/backend/x64/x64_code_cache.h b/src/xenia/cpu/backend/x64/x64_code_cache.h
index 0c2f83659..2c284e621 100644
--- a/src/xenia/cpu/backend/x64/x64_code_cache.h
+++ b/src/xenia/cpu/backend/x64/x64_code_cache.h
@@ -50,10 +50,10 @@ class X64CodeCache : public CodeCache {
                       size_t code_size, size_t stack_size);
   void* PlaceGuestCode(uint32_t guest_address, void* machine_code,
                        size_t code_size, size_t stack_size,
-                       FunctionInfo* function_info);
+                       GuestFunction* function_info);
   uint32_t PlaceData(const void* data, size_t length);
 
-  FunctionInfo* LookupFunction(uint64_t host_pc) override;
+  GuestFunction* LookupFunction(uint64_t host_pc) override;
 
  protected:
   // All executable code falls within 0x80000000 to 0x9FFFFFFF, so we can
@@ -111,7 +111,7 @@ class X64CodeCache : public CodeCache {
   // Sorted map by host PC base offsets to source function info.
   // This can be used to bsearch on host PC to find the guest function.
   // The key is [start address | end address].
-  std::vector<std::pair<uint64_t, FunctionInfo*>> generated_code_map_;
+  std::vector<std::pair<uint64_t, GuestFunction*>> generated_code_map_;
 };
 
 }  // namespace x64
diff --git a/src/xenia/cpu/backend/x64/x64_code_cache_win.cc b/src/xenia/cpu/backend/x64/x64_code_cache_win.cc
index a8cb5333d..563525fe1 100644
--- a/src/xenia/cpu/backend/x64/x64_code_cache_win.cc
+++ b/src/xenia/cpu/backend/x64/x64_code_cache_win.cc
@@ -18,6 +18,7 @@
 #include "xenia/base/math.h"
 #include "xenia/base/memory.h"
 #include "xenia/base/platform_win.h"
+#include "xenia/cpu/function.h"
 
 // When enabled, this will use Windows 8 APIs to get unwind info.
 // TODO(benvanik): figure out why the callback variant doesn't work.
diff --git a/src/xenia/cpu/backend/x64/x64_emitter.cc b/src/xenia/cpu/backend/x64/x64_emitter.cc
index e9b5e1c58..204775221 100644
--- a/src/xenia/cpu/backend/x64/x64_emitter.cc
+++ b/src/xenia/cpu/backend/x64/x64_emitter.cc
@@ -27,8 +27,9 @@
 #include "xenia/cpu/backend/x64/x64_stack_layout.h"
 #include "xenia/cpu/cpu_flags.h"
 #include "xenia/cpu/debug_info.h"
+#include "xenia/cpu/function.h"
 #include "xenia/cpu/processor.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/symbol.h"
 #include "xenia/cpu/thread_state.h"
 #include "xenia/debug/debugger.h"
 #include "xenia/profiling.h"
@@ -87,7 +88,7 @@ X64Emitter::X64Emitter(X64Backend* backend, XbyakAllocator* allocator)
 
 X64Emitter::~X64Emitter() = default;
 
-bool X64Emitter::Emit(FunctionInfo* function_info, HIRBuilder* builder,
+bool X64Emitter::Emit(GuestFunction* function, HIRBuilder* builder,
                       uint32_t debug_info_flags, DebugInfo* debug_info,
                       void*& out_code_address, size_t& out_code_size,
                       std::vector<SourceMapEntry>& out_source_map) {
@@ -96,6 +97,7 @@ bool X64Emitter::Emit(FunctionInfo* function_info, HIRBuilder* builder,
   // Reset.
   debug_info_ = debug_info;
   debug_info_flags_ = debug_info_flags;
+  trace_data_ = &function->trace_data();
   source_map_arena_.Reset();
 
   // Fill the generator with code.
@@ -106,7 +108,7 @@ bool X64Emitter::Emit(FunctionInfo* function_info, HIRBuilder* builder,
 
   // Copy the final code to the cache and relocate it.
   out_code_size = getSize();
-  out_code_address = Emplace(stack_size, function_info);
+  out_code_address = Emplace(stack_size, function);
 
   // Stash source map.
   source_map_arena_.CloneContents(out_source_map);
@@ -114,16 +116,16 @@ bool X64Emitter::Emit(FunctionInfo* function_info, HIRBuilder* builder,
   return true;
 }
 
-void* X64Emitter::Emplace(size_t stack_size, FunctionInfo* function_info) {
+void* X64Emitter::Emplace(size_t stack_size, GuestFunction* function) {
   // To avoid changing xbyak, we do a switcharoo here.
   // top_ points to the Xbyak buffer, and since we are in AutoGrow mode
   // it has pending relocations. We copy the top_ to our buffer, swap the
   // pointer, relocate, then return the original scratch pointer for use.
   uint8_t* old_address = top_;
   void* new_address;
-  if (function_info) {
-    new_address = code_cache_->PlaceGuestCode(function_info->address(), top_,
-                                              size_, stack_size, function_info);
+  if (function) {
+    new_address = code_cache_->PlaceGuestCode(function->address(), top_, size_,
+                                              stack_size, function);
   } else {
     new_address = code_cache_->PlaceHostCode(0, top_, size_, stack_size);
   }
@@ -177,8 +179,8 @@ bool X64Emitter::Emit(HIRBuilder* builder, size_t& out_stack_size) {
   // Safe now to do some tracing.
   if (debug_info_flags_ & DebugInfoFlags::kDebugInfoTraceFunctions) {
     // We require 32-bit addresses.
-    assert_true(uint64_t(debug_info_->trace_data().header()) < UINT_MAX);
-    auto trace_header = debug_info_->trace_data().header();
+    assert_true(uint64_t(trace_data_->header()) < UINT_MAX);
+    auto trace_header = trace_data_->header();
 
     // Call count.
     lock();
@@ -265,11 +267,10 @@ void X64Emitter::MarkSourceOffset(const Instr* i) {
   }
 
   if (debug_info_flags_ & DebugInfoFlags::kDebugInfoTraceFunctionCoverage) {
-    auto trace_data = debug_info_->trace_data();
     uint32_t instruction_index =
-        (entry->source_offset - trace_data.start_address()) / 4;
+        (entry->source_offset - trace_data_->start_address()) / 4;
     lock();
-    inc(qword[low_address(trace_data.instruction_execute_counts() +
+    inc(qword[low_address(trace_data_->instruction_execute_counts() +
                           instruction_index * 8)]);
   }
 }
@@ -341,8 +342,7 @@ extern "C" uint64_t ResolveFunction(void* raw_context,
   // TODO(benvanik): required?
   assert_not_zero(target_address);
 
-  Function* fn = NULL;
-  thread_state->processor()->ResolveFunction(target_address, &fn);
+  auto fn = thread_state->processor()->ResolveFunction(target_address);
   assert_not_null(fn);
   auto x64_fn = static_cast<X64Function*>(fn);
   uint64_t addr = reinterpret_cast<uint64_t>(x64_fn->machine_code());
@@ -350,11 +350,11 @@ extern "C" uint64_t ResolveFunction(void* raw_context,
   return addr;
 }
 
-void X64Emitter::Call(const hir::Instr* instr, FunctionInfo* symbol_info) {
-  assert_not_null(symbol_info);
-  auto fn = reinterpret_cast<X64Function*>(symbol_info->function());
+void X64Emitter::Call(const hir::Instr* instr, GuestFunction* function) {
+  assert_not_null(function);
+  auto fn = static_cast<X64Function*>(function);
   // Resolve address to the function to call and store in rax.
-  if (fn) {
+  if (fn->machine_code()) {
     // TODO(benvanik): is it worth it to do this? It removes the need for
     // a ResolveFunction call, but makes the table less useful.
     assert_zero(uint64_t(fn->machine_code()) & 0xFFFFFFFF00000000);
@@ -363,7 +363,7 @@ void X64Emitter::Call(const hir::Instr* instr, FunctionInfo* symbol_info) {
     // Load the pointer to the indirection table maintained in X64CodeCache.
     // The target dword will either contain the address of the generated code
     // or a thunk to ResolveAddress.
-    mov(ebx, symbol_info->address());
+    mov(ebx, function->address());
     mov(eax, dword[ebx]);
   }
 
@@ -418,43 +418,50 @@ void X64Emitter::CallIndirect(const hir::Instr* instr, const Reg64& reg) {
   }
 }
 
-uint64_t UndefinedCallExtern(void* raw_context, uint64_t symbol_info_ptr) {
-  auto symbol_info = reinterpret_cast<FunctionInfo*>(symbol_info_ptr);
-  XELOGW("undefined extern call to %.8X %s", symbol_info->address(),
-         symbol_info->name().c_str());
+uint64_t UndefinedCallExtern(void* raw_context, uint64_t function_ptr) {
+  auto function = reinterpret_cast<Function*>(function_ptr);
+  XELOGW("undefined extern call to %.8X %s", function->address(),
+         function->name().c_str());
   return 0;
 }
-void X64Emitter::CallExtern(const hir::Instr* instr,
-                            const FunctionInfo* symbol_info) {
-  if (symbol_info->behavior() == FunctionBehavior::kBuiltin &&
-      symbol_info->builtin_handler()) {
-    // rcx = context
-    // rdx = target host function
-    // r8  = arg0
-    // r9  = arg1
-    mov(rdx, reinterpret_cast<uint64_t>(symbol_info->builtin_handler()));
-    mov(r8, reinterpret_cast<uint64_t>(symbol_info->builtin_arg0()));
-    mov(r9, reinterpret_cast<uint64_t>(symbol_info->builtin_arg1()));
-    auto thunk = backend()->guest_to_host_thunk();
-    mov(rax, reinterpret_cast<uint64_t>(thunk));
-    call(rax);
-    ReloadECX();
-    ReloadEDX();
-    // rax = host return
-  } else if (symbol_info->behavior() == FunctionBehavior::kExtern &&
-             symbol_info->extern_handler()) {
-    // rcx = context
-    // rdx = target host function
-    mov(rdx, reinterpret_cast<uint64_t>(symbol_info->extern_handler()));
-    mov(r8, qword[rcx + offsetof(cpu::frontend::PPCContext, kernel_state)]);
-    auto thunk = backend()->guest_to_host_thunk();
-    mov(rax, reinterpret_cast<uint64_t>(thunk));
-    call(rax);
-    ReloadECX();
-    ReloadEDX();
-    // rax = host return
-  } else {
-    CallNative(UndefinedCallExtern, reinterpret_cast<uint64_t>(symbol_info));
+void X64Emitter::CallExtern(const hir::Instr* instr, const Function* function) {
+  bool undefined = true;
+  if (function->behavior() == Function::Behavior::kBuiltin) {
+    auto builtin_function = static_cast<const BuiltinFunction*>(function);
+    if (builtin_function->handler()) {
+      undefined = false;
+      // rcx = context
+      // rdx = target host function
+      // r8  = arg0
+      // r9  = arg1
+      mov(rdx, reinterpret_cast<uint64_t>(builtin_function->handler()));
+      mov(r8, reinterpret_cast<uint64_t>(builtin_function->arg0()));
+      mov(r9, reinterpret_cast<uint64_t>(builtin_function->arg1()));
+      auto thunk = backend()->guest_to_host_thunk();
+      mov(rax, reinterpret_cast<uint64_t>(thunk));
+      call(rax);
+      ReloadECX();
+      ReloadEDX();
+      // rax = host return
+    }
+  } else if (function->behavior() == Function::Behavior::kExtern) {
+    auto extern_function = static_cast<const GuestFunction*>(function);
+    if (extern_function->extern_handler()) {
+      undefined = false;
+      // rcx = context
+      // rdx = target host function
+      mov(rdx, reinterpret_cast<uint64_t>(extern_function->extern_handler()));
+      mov(r8, qword[rcx + offsetof(cpu::frontend::PPCContext, kernel_state)]);
+      auto thunk = backend()->guest_to_host_thunk();
+      mov(rax, reinterpret_cast<uint64_t>(thunk));
+      call(rax);
+      ReloadECX();
+      ReloadEDX();
+      // rax = host return
+    }
+  }
+  if (undefined) {
+    CallNative(UndefinedCallExtern, reinterpret_cast<uint64_t>(function));
   }
 }
 
diff --git a/src/xenia/cpu/backend/x64/x64_emitter.h b/src/xenia/cpu/backend/x64/x64_emitter.h
index 72bd62877..f920c93c1 100644
--- a/src/xenia/cpu/backend/x64/x64_emitter.h
+++ b/src/xenia/cpu/backend/x64/x64_emitter.h
@@ -17,7 +17,6 @@
 #include "xenia/cpu/hir/hir_builder.h"
 #include "xenia/cpu/hir/instr.h"
 #include "xenia/cpu/hir/value.h"
-#include "xenia/cpu/symbol_info.h"
 #include "xenia/debug/function_trace_data.h"
 #include "xenia/memory.h"
 
@@ -27,10 +26,7 @@
 
 namespace xe {
 namespace cpu {
-class DebugInfo;
-class FunctionInfo;
 class Processor;
-class SymbolInfo;
 }  // namespace cpu
 }  // namespace xe
 
@@ -118,7 +114,7 @@ class X64Emitter : public Xbyak::CodeGenerator {
   Processor* processor() const { return processor_; }
   X64Backend* backend() const { return backend_; }
 
-  bool Emit(FunctionInfo* function_info, hir::HIRBuilder* builder,
+  bool Emit(GuestFunction* function, hir::HIRBuilder* builder,
             uint32_t debug_info_flags, DebugInfo* debug_info,
             void*& out_code_address, size_t& out_code_size,
             std::vector<SourceMapEntry>& out_source_map);
@@ -163,9 +159,9 @@ class X64Emitter : public Xbyak::CodeGenerator {
   void Trap(uint16_t trap_type = 0);
   void UnimplementedInstr(const hir::Instr* i);
 
-  void Call(const hir::Instr* instr, FunctionInfo* symbol_info);
+  void Call(const hir::Instr* instr, GuestFunction* function);
   void CallIndirect(const hir::Instr* instr, const Xbyak::Reg64& reg);
-  void CallExtern(const hir::Instr* instr, const FunctionInfo* symbol_info);
+  void CallExtern(const hir::Instr* instr, const Function* function);
   void CallNative(void* fn);
   void CallNative(uint64_t (*fn)(void* raw_context));
   void CallNative(uint64_t (*fn)(void* raw_context, uint64_t arg0));
@@ -199,7 +195,7 @@ class X64Emitter : public Xbyak::CodeGenerator {
   size_t stack_size() const { return stack_size_; }
 
  protected:
-  void* Emplace(size_t stack_size, FunctionInfo* function_info = nullptr);
+  void* Emplace(size_t stack_size, GuestFunction* function = nullptr);
   bool Emit(hir::HIRBuilder* builder, size_t& out_stack_size);
   void EmitGetCurrentThreadId();
   void EmitTraceUserCallReturn();
@@ -218,6 +214,7 @@ class X64Emitter : public Xbyak::CodeGenerator {
 
   DebugInfo* debug_info_ = nullptr;
   uint32_t debug_info_flags_ = 0;
+  debug::FunctionTraceData* trace_data_ = nullptr;
   Arena source_map_arena_;
 
   size_t stack_size_ = 0;
diff --git a/src/xenia/cpu/backend/x64/x64_function.cc b/src/xenia/cpu/backend/x64/x64_function.cc
index 8ca5a6e34..668726e8f 100644
--- a/src/xenia/cpu/backend/x64/x64_function.cc
+++ b/src/xenia/cpu/backend/x64/x64_function.cc
@@ -18,8 +18,8 @@ namespace cpu {
 namespace backend {
 namespace x64 {
 
-X64Function::X64Function(FunctionInfo* symbol_info)
-    : Function(symbol_info), machine_code_(nullptr), machine_code_length_(0) {}
+X64Function::X64Function(Module* module, uint32_t address)
+    : GuestFunction(module, address) {}
 
 X64Function::~X64Function() {
   // machine_code_ is freed by code cache.
@@ -30,14 +30,6 @@ void X64Function::Setup(uint8_t* machine_code, size_t machine_code_length) {
   machine_code_length_ = machine_code_length;
 }
 
-bool X64Function::AddBreakpointImpl(debug::Breakpoint* breakpoint) {
-  return false;
-}
-
-bool X64Function::RemoveBreakpointImpl(debug::Breakpoint* breakpoint) {
-  return false;
-}
-
 bool X64Function::CallImpl(ThreadState* thread_state, uint32_t return_address) {
   auto backend =
       reinterpret_cast<X64Backend*>(thread_state->processor()->backend());
diff --git a/src/xenia/cpu/backend/x64/x64_function.h b/src/xenia/cpu/backend/x64/x64_function.h
index 86a08b18b..1f5e114ed 100644
--- a/src/xenia/cpu/backend/x64/x64_function.h
+++ b/src/xenia/cpu/backend/x64/x64_function.h
@@ -11,7 +11,6 @@
 #define XENIA_BACKEND_X64_X64_FUNCTION_H_
 
 #include "xenia/cpu/function.h"
-#include "xenia/cpu/symbol_info.h"
 #include "xenia/cpu/thread_state.h"
 
 namespace xe {
@@ -19,10 +18,10 @@ namespace cpu {
 namespace backend {
 namespace x64 {
 
-class X64Function : public Function {
+class X64Function : public GuestFunction {
  public:
-  X64Function(FunctionInfo* symbol_info);
-  virtual ~X64Function();
+  X64Function(Module* module, uint32_t address);
+  ~X64Function() override;
 
   uint8_t* machine_code() const override { return machine_code_; }
   size_t machine_code_length() const override { return machine_code_length_; }
@@ -30,13 +29,11 @@ class X64Function : public Function {
   void Setup(uint8_t* machine_code, size_t machine_code_length);
 
  protected:
-  bool AddBreakpointImpl(debug::Breakpoint* breakpoint) override;
-  bool RemoveBreakpointImpl(debug::Breakpoint* breakpoint) override;
   bool CallImpl(ThreadState* thread_state, uint32_t return_address) override;
 
  private:
-  uint8_t* machine_code_;
-  size_t machine_code_length_;
+  uint8_t* machine_code_ = nullptr;
+  size_t machine_code_length_ = 0;
 };
 
 }  // namespace x64
diff --git a/src/xenia/cpu/backend/x64/x64_sequences.cc b/src/xenia/cpu/backend/x64/x64_sequences.cc
index 465f8b034..42651b1f3 100644
--- a/src/xenia/cpu/backend/x64/x64_sequences.cc
+++ b/src/xenia/cpu/backend/x64/x64_sequences.cc
@@ -154,7 +154,7 @@ struct OffsetOp : Op<OffsetOp, KEY_TYPE_O> {
 };
 
 struct SymbolOp : Op<SymbolOp, KEY_TYPE_S> {
-  FunctionInfo* value;
+  Function* value;
 
  protected:
   template <typename T, KeyType KEY_TYPE>
@@ -162,7 +162,7 @@ struct SymbolOp : Op<SymbolOp, KEY_TYPE_S> {
   template <hir::Opcode OPCODE, typename... Ts>
   friend struct I;
   bool Load(const Instr::Op& op) {
-    this->value = op.symbol_info;
+    this->value = op.symbol;
     return true;
   }
 };
@@ -856,7 +856,8 @@ EMITTER_OPCODE_TABLE(OPCODE_TRAP_TRUE, TRAP_TRUE_I8, TRAP_TRUE_I16,
 // ============================================================================
 struct CALL : Sequence<CALL, I<OPCODE_CALL, VoidOp, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
-    e.Call(i.instr, i.src1.value);
+    assert_true(i.src1.value->is_guest());
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src1.value));
   }
 };
 EMITTER_OPCODE_TABLE(OPCODE_CALL, CALL);
@@ -867,60 +868,66 @@ EMITTER_OPCODE_TABLE(OPCODE_CALL, CALL);
 struct CALL_TRUE_I8
     : Sequence<CALL_TRUE_I8, I<OPCODE_CALL_TRUE, VoidOp, I8Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.test(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
 struct CALL_TRUE_I16
     : Sequence<CALL_TRUE_I16, I<OPCODE_CALL_TRUE, VoidOp, I16Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.test(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
 struct CALL_TRUE_I32
     : Sequence<CALL_TRUE_I32, I<OPCODE_CALL_TRUE, VoidOp, I32Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.test(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
 struct CALL_TRUE_I64
     : Sequence<CALL_TRUE_I64, I<OPCODE_CALL_TRUE, VoidOp, I64Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.test(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
 struct CALL_TRUE_F32
     : Sequence<CALL_TRUE_F32, I<OPCODE_CALL_TRUE, VoidOp, F32Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.vptest(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
 struct CALL_TRUE_F64
     : Sequence<CALL_TRUE_F64, I<OPCODE_CALL_TRUE, VoidOp, F64Op, SymbolOp>> {
   static void Emit(X64Emitter& e, const EmitArgType& i) {
+    assert_true(i.src2.value->is_guest());
     e.vptest(i.src1, i.src1);
     Xbyak::Label skip;
     e.jz(skip);
-    e.Call(i.instr, i.src2.value);
+    e.Call(i.instr, static_cast<GuestFunction*>(i.src2.value));
     e.L(skip);
   }
 };
diff --git a/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc b/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
index 10644b7a4..dfe31aaf4 100644
--- a/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
+++ b/src/xenia/cpu/compiler/passes/constant_propagation_pass.cc
@@ -91,9 +91,9 @@ bool ConstantPropagationPass::Run(HIRBuilder* builder) {
         case OPCODE_CALL_TRUE:
           if (i->src1.value->IsConstant()) {
             if (i->src1.value->IsConstantTrue()) {
-              auto symbol_info = i->src2.symbol_info;
+              auto symbol = i->src2.symbol;
               i->Replace(&OPCODE_CALL_info, i->flags);
-              i->src1.symbol_info = symbol_info;
+              i->src1.symbol = symbol;
             } else {
               i->Remove();
             }
@@ -101,13 +101,13 @@ bool ConstantPropagationPass::Run(HIRBuilder* builder) {
           break;
         case OPCODE_CALL_INDIRECT:
           if (i->src1.value->IsConstant()) {
-            FunctionInfo* symbol_info;
-            if (!processor_->LookupFunctionInfo(
-                    (uint32_t)i->src1.value->constant.i32, &symbol_info)) {
+            auto function = processor_->LookupFunction(
+                uint32_t(i->src1.value->constant.i32));
+            if (!function) {
               break;
             }
             i->Replace(&OPCODE_CALL_info, i->flags);
-            i->src1.symbol_info = symbol_info;
+            i->src1.symbol = function;
           }
           break;
         case OPCODE_CALL_INDIRECT_TRUE:
diff --git a/src/xenia/cpu/debug_info.cc b/src/xenia/cpu/debug_info.cc
index d3c71f87a..a685f930e 100644
--- a/src/xenia/cpu/debug_info.cc
+++ b/src/xenia/cpu/debug_info.cc
@@ -9,6 +9,7 @@
 
 #include "xenia/cpu/debug_info.h"
 
+#include <cstdio>
 #include <cstdlib>
 
 namespace xe {
diff --git a/src/xenia/cpu/debug_info.h b/src/xenia/cpu/debug_info.h
index 2d13f694e..b31a69a25 100644
--- a/src/xenia/cpu/debug_info.h
+++ b/src/xenia/cpu/debug_info.h
@@ -13,8 +13,6 @@
 #include <cstddef>
 #include <cstdint>
 
-#include "xenia/debug/function_trace_data.h"
-
 namespace xe {
 namespace cpu {
 
@@ -37,6 +35,9 @@ enum DebugInfoFlags : uint32_t {
   kDebugInfoAll = 0xFFFFFFFF,
 };
 
+// DEPRECATED
+// This will be getting removed or refactored to contain only on-demand
+// disassembly data.
 class DebugInfo {
  public:
   DebugInfo();
@@ -53,8 +54,6 @@ class DebugInfo {
     instruction_result_count_ = value;
   }
 
-  debug::FunctionTraceData& trace_data() { return trace_data_; }
-
   const char* source_disasm() const { return source_disasm_; }
   void set_source_disasm(char* value) { source_disasm_ = value; }
   const char* raw_hir_disasm() const { return raw_hir_disasm_; }
@@ -70,8 +69,6 @@ class DebugInfo {
   uint32_t address_reference_count_;
   uint32_t instruction_result_count_;
 
-  debug::FunctionTraceData trace_data_;
-
   char* source_disasm_;
   char* raw_hir_disasm_;
   char* hir_disasm_;
diff --git a/src/xenia/cpu/frontend/ppc_emit_control.cc b/src/xenia/cpu/frontend/ppc_emit_control.cc
index 633844987..179ab6800 100644
--- a/src/xenia/cpu/frontend/ppc_emit_control.cc
+++ b/src/xenia/cpu/frontend/ppc_emit_control.cc
@@ -53,7 +53,7 @@ int InstrEmit_branch(PPCHIRBuilder& f, const char* src, uint64_t cia,
     // recursion.
     uint32_t nia_value = nia->AsUint64() & 0xFFFFFFFF;
     bool is_recursion = false;
-    if (nia_value == f.symbol_info()->address() && lk) {
+    if (nia_value == f.function()->address() && lk) {
       is_recursion = true;
     }
     Label* label = is_recursion ? NULL : f.LookupLabel(nia_value);
@@ -71,14 +71,14 @@ int InstrEmit_branch(PPCHIRBuilder& f, const char* src, uint64_t cia,
       }
     } else {
       // Call function.
-      auto symbol_info = f.LookupFunction(nia_value);
+      auto function = f.LookupFunction(nia_value);
       if (cond) {
         if (!expect_true) {
           cond = f.IsFalse(cond);
         }
-        f.CallTrue(cond, symbol_info, call_flags);
+        f.CallTrue(cond, function, call_flags);
       } else {
-        f.Call(symbol_info, call_flags);
+        f.Call(function, call_flags);
       }
     }
   } else {
@@ -419,7 +419,7 @@ XEEMITTER(mcrf, 0x4C000000, XL)(PPCHIRBuilder& f, InstrData& i) {
 // System linkage (A-24)
 
 XEEMITTER(sc, 0x44000002, SC)(PPCHIRBuilder& f, InstrData& i) {
-  f.CallExtern(f.symbol_info());
+  f.CallExtern(f.function());
   return 0;
 }
 
diff --git a/src/xenia/cpu/frontend/ppc_frontend.cc b/src/xenia/cpu/frontend/ppc_frontend.cc
index 5dc9148ed..f0e7f1034 100644
--- a/src/xenia/cpu/frontend/ppc_frontend.cc
+++ b/src/xenia/cpu/frontend/ppc_frontend.cc
@@ -86,7 +86,7 @@ bool PPCFrontend::Initialize() {
   return true;
 }
 
-bool PPCFrontend::DeclareFunction(FunctionInfo* symbol_info) {
+bool PPCFrontend::DeclareFunction(GuestFunction* function) {
   // Could scan or something here.
   // Could also check to see if it's a well-known function type and classify
   // for later.
@@ -95,12 +95,10 @@ bool PPCFrontend::DeclareFunction(FunctionInfo* symbol_info) {
   return true;
 }
 
-bool PPCFrontend::DefineFunction(FunctionInfo* symbol_info,
-                                 uint32_t debug_info_flags,
-                                 Function** out_function) {
-  PPCTranslator* translator = translator_pool_.Allocate(this);
-  bool result =
-      translator->Translate(symbol_info, debug_info_flags, out_function);
+bool PPCFrontend::DefineFunction(GuestFunction* function,
+                                 uint32_t debug_info_flags) {
+  auto translator = translator_pool_.Allocate(this);
+  bool result = translator->Translate(function, debug_info_flags);
   translator_pool_.Release(translator);
   return result;
 }
diff --git a/src/xenia/cpu/frontend/ppc_frontend.h b/src/xenia/cpu/frontend/ppc_frontend.h
index 05718caa8..0f374457c 100644
--- a/src/xenia/cpu/frontend/ppc_frontend.h
+++ b/src/xenia/cpu/frontend/ppc_frontend.h
@@ -17,7 +17,6 @@
 #include "xenia/base/type_pool.h"
 #include "xenia/cpu/frontend/context_info.h"
 #include "xenia/cpu/function.h"
-#include "xenia/cpu/symbol_info.h"
 #include "xenia/memory.h"
 
 namespace xe {
@@ -35,8 +34,8 @@ class PPCTranslator;
 struct PPCBuiltins {
   xe::mutex global_lock;
   bool global_lock_taken;
-  FunctionInfo* check_global_lock;
-  FunctionInfo* handle_global_lock;
+  Function* check_global_lock;
+  Function* handle_global_lock;
 };
 
 class PPCFrontend {
@@ -51,9 +50,8 @@ class PPCFrontend {
   ContextInfo* context_info() const { return context_info_.get(); }
   PPCBuiltins* builtins() { return &builtins_; }
 
-  bool DeclareFunction(FunctionInfo* symbol_info);
-  bool DefineFunction(FunctionInfo* symbol_info, uint32_t debug_info_flags,
-                      Function** out_function);
+  bool DeclareFunction(GuestFunction* function);
+  bool DefineFunction(GuestFunction* function, uint32_t debug_info_flags);
 
  private:
   Processor* processor_;
diff --git a/src/xenia/cpu/frontend/ppc_hir_builder.cc b/src/xenia/cpu/frontend/ppc_hir_builder.cc
index a53c78b05..ebd2dfa4c 100644
--- a/src/xenia/cpu/frontend/ppc_hir_builder.cc
+++ b/src/xenia/cpu/frontend/ppc_hir_builder.cc
@@ -40,27 +40,29 @@ PPCHIRBuilder::PPCHIRBuilder(PPCFrontend* frontend)
 PPCHIRBuilder::~PPCHIRBuilder() = default;
 
 void PPCHIRBuilder::Reset() {
+  function_ = nullptr;
   start_address_ = 0;
+  instr_count_ = 0;
   instr_offset_list_ = NULL;
   label_list_ = NULL;
   with_debug_info_ = false;
   HIRBuilder::Reset();
 }
 
-bool PPCHIRBuilder::Emit(FunctionInfo* symbol_info, uint32_t flags) {
+bool PPCHIRBuilder::Emit(GuestFunction* function, uint32_t flags) {
   SCOPE_profile_cpu_f("cpu");
 
   Memory* memory = frontend_->memory();
 
-  symbol_info_ = symbol_info;
-  start_address_ = symbol_info->address();
-  instr_count_ = (symbol_info->end_address() - symbol_info->address()) / 4 + 1;
+  function_ = function;
+  start_address_ = function_->address();
+  instr_count_ = (function_->end_address() - function_->address()) / 4 + 1;
 
   with_debug_info_ = (flags & EMIT_DEBUG_COMMENTS) == EMIT_DEBUG_COMMENTS;
   if (with_debug_info_) {
-    CommentFormat("%s fn %.8X-%.8X %s", symbol_info->module()->name().c_str(),
-                  symbol_info->address(), symbol_info->end_address(),
-                  symbol_info->name().c_str());
+    CommentFormat("%s fn %.8X-%.8X %s", function_->module()->name().c_str(),
+                  function_->address(), function_->end_address(),
+                  function_->name().c_str());
   }
 
   // Allocate offset list.
@@ -78,8 +80,8 @@ bool PPCHIRBuilder::Emit(FunctionInfo* symbol_info, uint32_t flags) {
   // Always mark entry with label.
   label_list_[0] = NewLabel();
 
-  uint32_t start_address = symbol_info->address();
-  uint32_t end_address = symbol_info->end_address();
+  uint32_t start_address = function_->address();
+  uint32_t end_address = function_->end_address();
   InstrData i;
   for (uint32_t address = start_address, offset = 0; address <= end_address;
        address += 4, offset++) {
@@ -165,13 +167,8 @@ void PPCHIRBuilder::AnnotateLabel(uint32_t address, Label* label) {
   memcpy(label->name, name_buffer, sizeof(name_buffer));
 }
 
-FunctionInfo* PPCHIRBuilder::LookupFunction(uint32_t address) {
-  Processor* processor = frontend_->processor();
-  FunctionInfo* symbol_info;
-  if (!processor->LookupFunctionInfo(address, &symbol_info)) {
-    return nullptr;
-  }
-  return symbol_info;
+Function* PPCHIRBuilder::LookupFunction(uint32_t address) {
+  return frontend_->processor()->LookupFunction(address);
 }
 
 Label* PPCHIRBuilder::LookupLabel(uint32_t address) {
diff --git a/src/xenia/cpu/frontend/ppc_hir_builder.h b/src/xenia/cpu/frontend/ppc_hir_builder.h
index 0611a4af1..7d1900d92 100644
--- a/src/xenia/cpu/frontend/ppc_hir_builder.h
+++ b/src/xenia/cpu/frontend/ppc_hir_builder.h
@@ -13,7 +13,6 @@
 #include "xenia/base/string_buffer.h"
 #include "xenia/cpu/hir/hir_builder.h"
 #include "xenia/cpu/function.h"
-#include "xenia/cpu/symbol_info.h"
 
 namespace xe {
 namespace cpu {
@@ -28,18 +27,18 @@ class PPCHIRBuilder : public hir::HIRBuilder {
 
  public:
   PPCHIRBuilder(PPCFrontend* frontend);
-  virtual ~PPCHIRBuilder();
+  ~PPCHIRBuilder() override;
 
-  virtual void Reset();
+  void Reset() override;
 
   enum EmitFlags {
     // Emit comment nodes.
     EMIT_DEBUG_COMMENTS = 1 << 0,
   };
-  bool Emit(FunctionInfo* symbol_info, uint32_t flags);
+  bool Emit(GuestFunction* function, uint32_t flags);
 
-  FunctionInfo* symbol_info() const { return symbol_info_; }
-  FunctionInfo* LookupFunction(uint32_t address);
+  GuestFunction* function() const { return function_; }
+  Function* LookupFunction(uint32_t address);
   Label* LookupLabel(uint32_t address);
 
   Value* LoadLR();
@@ -83,7 +82,6 @@ class PPCHIRBuilder : public hir::HIRBuilder {
  private:
   void AnnotateLabel(uint32_t address, Label* label);
 
- private:
   PPCFrontend* frontend_;
 
   // Reset whenever needed:
@@ -91,7 +89,7 @@ class PPCHIRBuilder : public hir::HIRBuilder {
 
   // Reset each Emit:
   bool with_debug_info_;
-  FunctionInfo* symbol_info_;
+  GuestFunction* function_;
   uint64_t start_address_;
   uint64_t instr_count_;
   Instr** instr_offset_list_;
diff --git a/src/xenia/cpu/frontend/ppc_scanner.cc b/src/xenia/cpu/frontend/ppc_scanner.cc
index ad5d699b2..a8e157781 100644
--- a/src/xenia/cpu/frontend/ppc_scanner.cc
+++ b/src/xenia/cpu/frontend/ppc_scanner.cc
@@ -35,11 +35,10 @@ PPCScanner::~PPCScanner() {}
 
 bool PPCScanner::IsRestGprLr(uint32_t address) {
   auto function = frontend_->processor()->QueryFunction(address);
-  return function &&
-         function->symbol_info()->behavior() == FunctionBehavior::kEpilogReturn;
+  return function && function->behavior() == Function::Behavior::kEpilogReturn;
 }
 
-bool PPCScanner::Scan(FunctionInfo* symbol_info, DebugInfo* debug_info) {
+bool PPCScanner::Scan(GuestFunction* function, DebugInfo* debug_info) {
   // This is a simple basic block analyizer. It walks the start address to the
   // end address looking for branches. Each span of instructions between
   // branches is considered a basic block. When the last blr (that has no
@@ -49,14 +48,14 @@ bool PPCScanner::Scan(FunctionInfo* symbol_info, DebugInfo* debug_info) {
 
   Memory* memory = frontend_->memory();
 
-  LOGPPC("Analyzing function %.8X...", symbol_info->address());
+  LOGPPC("Analyzing function %.8X...", function->address());
 
   // For debug info, only if needed.
   uint32_t address_reference_count = 0;
   uint32_t instruction_result_count = 0;
 
-  uint32_t start_address = static_cast<uint32_t>(symbol_info->address());
-  uint32_t end_address = static_cast<uint32_t>(symbol_info->end_address());
+  uint32_t start_address = static_cast<uint32_t>(function->address());
+  uint32_t end_address = static_cast<uint32_t>(function->end_address());
   uint32_t address = start_address;
   uint32_t furthest_target = start_address;
   size_t blocks_found = 0;
@@ -270,7 +269,7 @@ bool PPCScanner::Scan(FunctionInfo* symbol_info, DebugInfo* debug_info) {
     LOGPPC("Function ran under: %.8X-%.8X ended at %.8X", start_address,
            end_address, address + 4);
   }
-  symbol_info->set_end_address(address);
+  function->set_end_address(address);
 
   // If there's spare bits at the end, split the function.
   // TODO(benvanik): splitting?
@@ -289,13 +288,13 @@ bool PPCScanner::Scan(FunctionInfo* symbol_info, DebugInfo* debug_info) {
   return true;
 }
 
-std::vector<BlockInfo> PPCScanner::FindBlocks(FunctionInfo* symbol_info) {
+std::vector<BlockInfo> PPCScanner::FindBlocks(GuestFunction* function) {
   Memory* memory = frontend_->memory();
 
   std::map<uint32_t, BlockInfo> block_map;
 
-  uint32_t start_address = symbol_info->address();
-  uint32_t end_address = symbol_info->end_address();
+  uint32_t start_address = function->address();
+  uint32_t end_address = function->end_address();
   bool in_block = false;
   uint32_t block_start = 0;
   InstrData i;
diff --git a/src/xenia/cpu/frontend/ppc_scanner.h b/src/xenia/cpu/frontend/ppc_scanner.h
index ad264cdcd..b2c893d46 100644
--- a/src/xenia/cpu/frontend/ppc_scanner.h
+++ b/src/xenia/cpu/frontend/ppc_scanner.h
@@ -13,7 +13,7 @@
 #include <vector>
 
 #include "xenia/cpu/debug_info.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/function.h"
 
 namespace xe {
 namespace cpu {
@@ -21,25 +21,24 @@ namespace frontend {
 
 class PPCFrontend;
 
-typedef struct BlockInfo_t {
+struct BlockInfo {
   uint32_t start_address;
   uint32_t end_address;
-} BlockInfo;
+};
 
 class PPCScanner {
  public:
   PPCScanner(PPCFrontend* frontend);
   ~PPCScanner();
 
-  bool Scan(FunctionInfo* symbol_info, DebugInfo* debug_info);
+  bool Scan(GuestFunction* function, DebugInfo* debug_info);
 
-  std::vector<BlockInfo> FindBlocks(FunctionInfo* symbol_info);
+  std::vector<BlockInfo> FindBlocks(GuestFunction* function);
 
  private:
   bool IsRestGprLr(uint32_t address);
 
- private:
-  PPCFrontend* frontend_;
+  PPCFrontend* frontend_ = nullptr;
 };
 
 }  // namespace frontend
diff --git a/src/xenia/cpu/frontend/ppc_translator.cc b/src/xenia/cpu/frontend/ppc_translator.cc
index 7d02d46c1..03eb5e3b4 100644
--- a/src/xenia/cpu/frontend/ppc_translator.cc
+++ b/src/xenia/cpu/frontend/ppc_translator.cc
@@ -99,9 +99,8 @@ PPCTranslator::PPCTranslator(PPCFrontend* frontend) : frontend_(frontend) {
 
 PPCTranslator::~PPCTranslator() = default;
 
-bool PPCTranslator::Translate(FunctionInfo* symbol_info,
-                              uint32_t debug_info_flags,
-                              Function** out_function) {
+bool PPCTranslator::Translate(GuestFunction* function,
+                              uint32_t debug_info_flags) {
   SCOPE_profile_cpu_f("cpu");
 
   // Reset() all caching when we leave.
@@ -137,7 +136,7 @@ bool PPCTranslator::Translate(FunctionInfo* symbol_info,
   }
 
   // Scan the function to find its extents and gather debug data.
-  if (!scanner_->Scan(symbol_info, debug_info.get())) {
+  if (!scanner_->Scan(function, debug_info.get())) {
     return false;
   }
 
@@ -153,19 +152,19 @@ bool PPCTranslator::Translate(FunctionInfo* symbol_info,
     if (debug_info_flags & DebugInfoFlags::kDebugInfoTraceFunctionCoverage) {
       // Additional space for instruction coverage counts.
       trace_data_size += debug::FunctionTraceData::SizeOfInstructionCounts(
-          symbol_info->address(), symbol_info->end_address());
+          function->address(), function->end_address());
     }
     uint8_t* trace_data = debugger->AllocateFunctionTraceData(trace_data_size);
     if (trace_data) {
-      debug_info->trace_data().Reset(trace_data, trace_data_size,
-                                     symbol_info->address(),
-                                     symbol_info->end_address());
+      function->trace_data().Reset(trace_data, trace_data_size,
+                                   function->address(),
+                                   function->end_address());
     }
   }
 
   // Stash source.
   if (debug_info_flags & DebugInfoFlags::kDebugInfoDisasmSource) {
-    DumpSource(symbol_info, &string_buffer_);
+    DumpSource(function, &string_buffer_);
     debug_info->set_source_disasm(string_buffer_.ToString());
     string_buffer_.Reset();
   }
@@ -179,7 +178,7 @@ bool PPCTranslator::Translate(FunctionInfo* symbol_info,
   if (debug_info) {
     emit_flags |= PPCHIRBuilder::EMIT_DEBUG_COMMENTS;
   }
-  if (!builder_->Emit(symbol_info, emit_flags)) {
+  if (!builder_->Emit(function, emit_flags)) {
     return false;
   }
 
@@ -203,27 +202,26 @@ bool PPCTranslator::Translate(FunctionInfo* symbol_info,
   }
 
   // Assemble to backend machine code.
-  if (!assembler_->Assemble(symbol_info, builder_.get(), debug_info_flags,
-                            std::move(debug_info), out_function)) {
+  if (!assembler_->Assemble(function, builder_.get(), debug_info_flags,
+                            std::move(debug_info))) {
     return false;
   }
 
   return true;
 };
 
-void PPCTranslator::DumpSource(FunctionInfo* symbol_info,
+void PPCTranslator::DumpSource(GuestFunction* function,
                                StringBuffer* string_buffer) {
   Memory* memory = frontend_->memory();
 
   string_buffer->AppendFormat(
-      "%s fn %.8X-%.8X %s\n", symbol_info->module()->name().c_str(),
-      symbol_info->address(), symbol_info->end_address(),
-      symbol_info->name().c_str());
+      "%s fn %.8X-%.8X %s\n", function->module()->name().c_str(),
+      function->address(), function->end_address(), function->name().c_str());
 
-  auto blocks = scanner_->FindBlocks(symbol_info);
+  auto blocks = scanner_->FindBlocks(function);
 
-  uint32_t start_address = symbol_info->address();
-  uint32_t end_address = symbol_info->end_address();
+  uint32_t start_address = function->address();
+  uint32_t end_address = function->end_address();
   InstrData i;
   auto block_it = blocks.begin();
   for (uint32_t address = start_address, offset = 0; address <= end_address;
diff --git a/src/xenia/cpu/frontend/ppc_translator.h b/src/xenia/cpu/frontend/ppc_translator.h
index f0263c859..7aaccf6b9 100644
--- a/src/xenia/cpu/frontend/ppc_translator.h
+++ b/src/xenia/cpu/frontend/ppc_translator.h
@@ -15,7 +15,7 @@
 #include "xenia/base/string_buffer.h"
 #include "xenia/cpu/backend/assembler.h"
 #include "xenia/cpu/compiler/compiler.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/function.h"
 
 namespace xe {
 namespace cpu {
@@ -30,13 +30,11 @@ class PPCTranslator {
   PPCTranslator(PPCFrontend* frontend);
   ~PPCTranslator();
 
-  bool Translate(FunctionInfo* symbol_info, uint32_t debug_info_flags,
-                 Function** out_function);
+  bool Translate(GuestFunction* function, uint32_t debug_info_flags);
 
  private:
-  void DumpSource(FunctionInfo* symbol_info, StringBuffer* string_buffer);
+  void DumpSource(GuestFunction* function, StringBuffer* string_buffer);
 
- private:
   PPCFrontend* frontend_;
   std::unique_ptr<PPCScanner> scanner_;
   std::unique_ptr<PPCHIRBuilder> builder_;
diff --git a/src/xenia/cpu/frontend/testing/ppc_testing_main.cc b/src/xenia/cpu/frontend/testing/ppc_testing_main.cc
index abcfbe1f2..0660c80e1 100644
--- a/src/xenia/cpu/frontend/testing/ppc_testing_main.cc
+++ b/src/xenia/cpu/frontend/testing/ppc_testing_main.cc
@@ -224,8 +224,8 @@ class TestRunner {
     }
 
     // Execute test.
-    xe::cpu::Function* fn = nullptr;
-    if (!processor->ResolveFunction(test_case.address, &fn)) {
+    auto fn = processor->ResolveFunction(test_case.address);
+    if (!fn) {
       XELOGE("Entry function not found");
       return false;
     }
@@ -238,7 +238,9 @@ class TestRunner {
     bool result = CheckTestResults(test_case);
     if (!result) {
       // Also dump all disasm/etc.
-      fn->debug_info()->Dump();
+      if (fn->is_guest()) {
+        static_cast<xe::cpu::GuestFunction*>(fn)->debug_info()->Dump();
+      }
     }
 
     return result;
diff --git a/src/xenia/cpu/function.cc b/src/xenia/cpu/function.cc
index e9f915b61..256f3a77d 100644
--- a/src/xenia/cpu/function.cc
+++ b/src/xenia/cpu/function.cc
@@ -10,7 +10,7 @@
 #include "xenia/cpu/function.h"
 
 #include "xenia/base/logging.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/symbol.h"
 #include "xenia/cpu/thread_state.h"
 
 namespace xe {
@@ -18,12 +18,56 @@ namespace cpu {
 
 using xe::debug::Breakpoint;
 
-Function::Function(FunctionInfo* symbol_info)
-    : address_(symbol_info->address()), symbol_info_(symbol_info) {}
+Function::Function(Module* module, uint32_t address)
+    : Symbol(Symbol::Type::kFunction, module, address) {}
 
 Function::~Function() = default;
 
-const SourceMapEntry* Function::LookupSourceOffset(uint32_t offset) const {
+BuiltinFunction::BuiltinFunction(Module* module, uint32_t address)
+    : Function(module, address) {
+  behavior_ = Behavior::kBuiltin;
+}
+
+BuiltinFunction::~BuiltinFunction() = default;
+
+void BuiltinFunction::SetupBuiltin(Handler handler, void* arg0, void* arg1) {
+  behavior_ = Behavior::kBuiltin;
+  handler_ = handler;
+  arg0_ = arg0;
+  arg1_ = arg1;
+}
+
+bool BuiltinFunction::Call(ThreadState* thread_state, uint32_t return_address) {
+  // SCOPE_profile_cpu_f("cpu");
+
+  ThreadState* original_thread_state = ThreadState::Get();
+  if (original_thread_state != thread_state) {
+    ThreadState::Bind(thread_state);
+  }
+
+  assert_not_null(handler_);
+  handler_(thread_state->context(), arg0_, arg1_);
+
+  if (original_thread_state != thread_state) {
+    ThreadState::Bind(original_thread_state);
+  }
+
+  return true;
+}
+
+GuestFunction::GuestFunction(Module* module, uint32_t address)
+    : Function(module, address) {
+  behavior_ = Behavior::kDefault;
+}
+
+GuestFunction::~GuestFunction() = default;
+
+void GuestFunction::SetupExtern(ExternHandler handler) {
+  behavior_ = Behavior::kExtern;
+  extern_handler_ = handler;
+}
+
+const SourceMapEntry* GuestFunction::LookupSourceOffset(uint32_t offset) const {
   // TODO(benvanik): binary search? We know the list is sorted by code order.
   for (size_t i = 0; i < source_map_.size(); ++i) {
     const auto& entry = source_map_[i];
@@ -34,7 +78,7 @@ const SourceMapEntry* Function::LookupSourceOffset(uint32_t offset) const {
   return nullptr;
 }
 
-const SourceMapEntry* Function::LookupHIROffset(uint32_t offset) const {
+const SourceMapEntry* GuestFunction::LookupHIROffset(uint32_t offset) const {
   // TODO(benvanik): binary search? We know the list is sorted by code order.
   for (size_t i = 0; i < source_map_.size(); ++i) {
     const auto& entry = source_map_[i];
@@ -45,7 +89,7 @@ const SourceMapEntry* Function::LookupHIROffset(uint32_t offset) const {
   return nullptr;
 }
 
-const SourceMapEntry* Function::LookupCodeOffset(uint32_t offset) const {
+const SourceMapEntry* GuestFunction::LookupCodeOffset(uint32_t offset) const {
   // TODO(benvanik): binary search? We know the list is sorted by code order.
   for (int64_t i = source_map_.size() - 1; i >= 0; --i) {
     const auto& entry = source_map_[i];
@@ -56,49 +100,7 @@ const SourceMapEntry* Function::LookupCodeOffset(uint32_t offset) const {
   return source_map_.empty() ? nullptr : &source_map_[0];
 }
 
-bool Function::AddBreakpoint(Breakpoint* breakpoint) {
-  std::lock_guard<xe::mutex> guard(lock_);
-  bool found = false;
-  for (auto other : breakpoints_) {
-    if (other == breakpoint) {
-      found = true;
-      break;
-    }
-  }
-  if (found) {
-    return true;
-  } else {
-    breakpoints_.push_back(breakpoint);
-    return AddBreakpointImpl(breakpoint);
-  }
-}
-
-bool Function::RemoveBreakpoint(Breakpoint* breakpoint) {
-  std::lock_guard<xe::mutex> guard(lock_);
-  for (auto it = breakpoints_.begin(); it != breakpoints_.end(); ++it) {
-    if (*it == breakpoint) {
-      if (!RemoveBreakpointImpl(breakpoint)) {
-        return false;
-      }
-      breakpoints_.erase(it);
-    }
-  }
-  return false;
-}
-
-Breakpoint* Function::FindBreakpoint(uint32_t address) {
-  std::lock_guard<xe::mutex> guard(lock_);
-  Breakpoint* result = nullptr;
-  for (auto breakpoint : breakpoints_) {
-    if (breakpoint->address() == address) {
-      result = breakpoint;
-      break;
-    }
-  }
-  return result;
-}
-
-bool Function::Call(ThreadState* thread_state, uint32_t return_address) {
+bool GuestFunction::Call(ThreadState* thread_state, uint32_t return_address) {
   // SCOPE_profile_cpu_f("cpu");
 
   ThreadState* original_thread_state = ThreadState::Get();
@@ -106,29 +108,25 @@ bool Function::Call(ThreadState* thread_state, uint32_t return_address) {
     ThreadState::Bind(thread_state);
   }
 
-  bool result = true;
-
-  if (symbol_info_->behavior() == FunctionBehavior::kBuiltin) {
-    auto handler = symbol_info_->builtin_handler();
-    assert_not_null(handler);
-    handler(thread_state->context(), symbol_info_->builtin_arg0(),
-            symbol_info_->builtin_arg1());
-  } else if (symbol_info_->behavior() == FunctionBehavior::kExtern) {
-    auto handler = symbol_info_->extern_handler();
-    if (handler) {
-      handler(thread_state->context(), thread_state->context()->kernel_state);
+  bool result = false;
+  if (behavior_ == Behavior::kExtern) {
+    // Special handling for extern functions to speed things up (we don't
+    // trampoline into guest code only to trampoline back out).
+    if (extern_handler_) {
+      extern_handler_(thread_state->context(),
+                      thread_state->context()->kernel_state);
     } else {
-      XELOGW("undefined extern call to %.8X %s", symbol_info_->address(),
-             symbol_info_->name().c_str());
+      XELOGW("undefined extern call to %.8X %s", address(), name().c_str());
       result = false;
     }
   } else {
-    CallImpl(thread_state, return_address);
+    result = CallImpl(thread_state, return_address);
   }
 
   if (original_thread_state != thread_state) {
     ThreadState::Bind(original_thread_state);
   }
+
   return result;
 }
 
diff --git a/src/xenia/cpu/function.h b/src/xenia/cpu/function.h
index 74e758aaf..ad1d799b6 100644
--- a/src/xenia/cpu/function.h
+++ b/src/xenia/cpu/function.h
@@ -11,32 +11,89 @@
 #define XENIA_CPU_FUNCTION_H_
 
 #include <memory>
-#include <mutex>
 #include <vector>
 
 #include "xenia/base/mutex.h"
 #include "xenia/cpu/debug_info.h"
+#include "xenia/cpu/frontend/ppc_context.h"
+#include "xenia/cpu/symbol.h"
 #include "xenia/cpu/thread_state.h"
 #include "xenia/debug/breakpoint.h"
+#include "xenia/debug/function_trace_data.h"
 
 namespace xe {
 namespace cpu {
 
-class FunctionInfo;
-
 struct SourceMapEntry {
   uint32_t source_offset;  // Original source address/offset.
   uint32_t hir_offset;     // Block ordinal (16b) | Instr ordinal (16b)
   uint32_t code_offset;    // Offset from emitted code start.
 };
 
-class Function {
+class Function : public Symbol {
  public:
-  Function(FunctionInfo* symbol_info);
-  virtual ~Function();
+  enum class Behavior {
+    kDefault = 0,
+    kProlog,
+    kEpilog,
+    kEpilogReturn,
+    kBuiltin,
+    kExtern,
+  };
+
+  ~Function() override;
 
   uint32_t address() const { return address_; }
-  FunctionInfo* symbol_info() const { return symbol_info_; }
+  bool has_end_address() const { return end_address_ > 0; }
+  uint32_t end_address() const { return end_address_; }
+  void set_end_address(uint32_t value) { end_address_ = value; }
+  Behavior behavior() const { return behavior_; }
+  void set_behavior(Behavior value) { behavior_ = value; }
+  bool is_guest() const { return behavior_ != Behavior::kBuiltin; }
+
+  virtual bool Call(ThreadState* thread_state, uint32_t return_address) = 0;
+
+ protected:
+  Function(Module* module, uint32_t address);
+
+  uint32_t end_address_ = 0;
+  Behavior behavior_ = Behavior::kDefault;
+};
+
+class BuiltinFunction : public Function {
+ public:
+  typedef void (*Handler)(frontend::PPCContext* ppc_context, void* arg0,
+                          void* arg1);
+
+  BuiltinFunction(Module* module, uint32_t address);
+  ~BuiltinFunction() override;
+
+  void SetupBuiltin(Handler handler, void* arg0, void* arg1);
+
+  Handler handler() const { return handler_; }
+  void* arg0() const { return arg0_; }
+  void* arg1() const { return arg1_; }
+
+  bool Call(ThreadState* thread_state, uint32_t return_address) override;
+
+ protected:
+  Handler handler_ = nullptr;
+  void* arg0_ = nullptr;
+  void* arg1_ = nullptr;
+};
+
+class GuestFunction : public Function {
+ public:
+  typedef void (*ExternHandler)(frontend::PPCContext* ppc_context,
+                                kernel::KernelState* kernel_state);
+
+  GuestFunction(Module* module, uint32_t address);
+  ~GuestFunction() override;
+
+  uint32_t address() const { return address_; }
+  bool has_end_address() const { return end_address_ > 0; }
+  uint32_t end_address() const { return end_address_; }
+  void set_end_address(uint32_t value) { end_address_ = value; }
 
   virtual uint8_t* machine_code() const = 0;
   virtual size_t machine_code_length() const = 0;
@@ -45,32 +102,26 @@ class Function {
   void set_debug_info(std::unique_ptr<DebugInfo> debug_info) {
     debug_info_ = std::move(debug_info);
   }
+  debug::FunctionTraceData& trace_data() { return trace_data_; }
   std::vector<SourceMapEntry>& source_map() { return source_map_; }
 
+  ExternHandler extern_handler() const { return extern_handler_; }
+  void SetupExtern(ExternHandler handler);
+
   const SourceMapEntry* LookupSourceOffset(uint32_t offset) const;
   const SourceMapEntry* LookupHIROffset(uint32_t offset) const;
   const SourceMapEntry* LookupCodeOffset(uint32_t offset) const;
 
-  bool AddBreakpoint(debug::Breakpoint* breakpoint);
-  bool RemoveBreakpoint(debug::Breakpoint* breakpoint);
-
-  bool Call(ThreadState* thread_state, uint32_t return_address);
+  bool Call(ThreadState* thread_state, uint32_t return_address) override;
 
  protected:
-  debug::Breakpoint* FindBreakpoint(uint32_t address);
-  virtual bool AddBreakpointImpl(debug::Breakpoint* breakpoint) { return 0; }
-  virtual bool RemoveBreakpointImpl(debug::Breakpoint* breakpoint) { return 0; }
   virtual bool CallImpl(ThreadState* thread_state, uint32_t return_address) = 0;
 
  protected:
-  uint32_t address_;
-  FunctionInfo* symbol_info_;
   std::unique_ptr<DebugInfo> debug_info_;
+  debug::FunctionTraceData trace_data_;
   std::vector<SourceMapEntry> source_map_;
-
-  // TODO(benvanik): move elsewhere? DebugData?
-  xe::mutex lock_;
-  std::vector<debug::Breakpoint*> breakpoints_;
+  ExternHandler extern_handler_ = nullptr;
 };
 
 }  // namespace cpu
diff --git a/src/xenia/cpu/hir/hir_builder.cc b/src/xenia/cpu/hir/hir_builder.cc
index 2d14dd180..6bd644f16 100644
--- a/src/xenia/cpu/hir/hir_builder.cc
+++ b/src/xenia/cpu/hir/hir_builder.cc
@@ -13,10 +13,11 @@
 #include <cstring>
 
 #include "xenia/base/assert.h"
+#include "xenia/cpu/function.h"
 #include "xenia/cpu/hir/block.h"
 #include "xenia/cpu/hir/instr.h"
 #include "xenia/cpu/hir/label.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/symbol.h"
 #include "xenia/profiling.h"
 
 // Will scribble arena memory to hopefully find use before clears.
@@ -162,7 +163,7 @@ void HIRBuilder::DumpOp(StringBuffer* str, OpcodeSignatureType sig_type,
       break;
     case OPCODE_SIG_TYPE_S:
       if (true) {
-        auto target = op->symbol_info;
+        auto target = op->symbol;
         str->Append(!target->name().empty() ? target->name() : "<fn>");
       }
       break;
@@ -820,25 +821,24 @@ void HIRBuilder::TrapTrue(Value* cond, uint16_t trap_code) {
   EndBlock();
 }
 
-void HIRBuilder::Call(FunctionInfo* symbol_info, uint16_t call_flags) {
+void HIRBuilder::Call(Function* symbol, uint16_t call_flags) {
   Instr* i = AppendInstr(OPCODE_CALL_info, call_flags);
-  i->src1.symbol_info = symbol_info;
+  i->src1.symbol = symbol;
   i->src2.value = i->src3.value = NULL;
   EndBlock();
 }
 
-void HIRBuilder::CallTrue(Value* cond, FunctionInfo* symbol_info,
-                          uint16_t call_flags) {
+void HIRBuilder::CallTrue(Value* cond, Function* symbol, uint16_t call_flags) {
   if (cond->IsConstant()) {
     if (cond->IsConstantTrue()) {
-      Call(symbol_info, call_flags);
+      Call(symbol, call_flags);
     }
     return;
   }
 
   Instr* i = AppendInstr(OPCODE_CALL_TRUE_info, call_flags);
   i->set_src1(cond);
-  i->src2.symbol_info = symbol_info;
+  i->src2.symbol = symbol;
   i->src3.value = NULL;
   EndBlock();
 }
@@ -868,9 +868,9 @@ void HIRBuilder::CallIndirectTrue(Value* cond, Value* value,
   EndBlock();
 }
 
-void HIRBuilder::CallExtern(FunctionInfo* symbol_info) {
+void HIRBuilder::CallExtern(Function* symbol) {
   Instr* i = AppendInstr(OPCODE_CALL_EXTERN_info, 0);
-  i->src1.symbol_info = symbol_info;
+  i->src1.symbol = symbol;
   i->src2.value = i->src3.value = NULL;
   EndBlock();
 }
diff --git a/src/xenia/cpu/hir/hir_builder.h b/src/xenia/cpu/hir/hir_builder.h
index 00a6f6b96..1e0966d9a 100644
--- a/src/xenia/cpu/hir/hir_builder.h
+++ b/src/xenia/cpu/hir/hir_builder.h
@@ -83,12 +83,11 @@ class HIRBuilder {
   void Trap(uint16_t trap_code = 0);
   void TrapTrue(Value* cond, uint16_t trap_code = 0);
 
-  void Call(FunctionInfo* symbol_info, uint16_t call_flags = 0);
-  void CallTrue(Value* cond, FunctionInfo* symbol_info,
-                uint16_t call_flags = 0);
+  void Call(Function* symbol, uint16_t call_flags = 0);
+  void CallTrue(Value* cond, Function* symbol, uint16_t call_flags = 0);
   void CallIndirect(Value* value, uint16_t call_flags = 0);
   void CallIndirectTrue(Value* cond, Value* value, uint16_t call_flags = 0);
-  void CallExtern(FunctionInfo* symbol_info);
+  void CallExtern(Function* symbol);
   void Return();
   void ReturnTrue(Value* cond);
   void SetReturnAddress(Value* value);
diff --git a/src/xenia/cpu/hir/instr.h b/src/xenia/cpu/hir/instr.h
index eee365acd..6c9ad9731 100644
--- a/src/xenia/cpu/hir/instr.h
+++ b/src/xenia/cpu/hir/instr.h
@@ -15,7 +15,7 @@
 
 namespace xe {
 namespace cpu {
-class FunctionInfo;
+class Function;
 }  // namespace cpu
 }  // namespace xe
 
@@ -37,7 +37,7 @@ class Instr {
   uint32_t ordinal;
 
   typedef union {
-    FunctionInfo* symbol_info;
+    Function* symbol;
     Label* label;
     Value* value;
     uint64_t offset;
diff --git a/src/xenia/cpu/instrument.cc b/src/xenia/cpu/instrument.cc
deleted file mode 100644
index 432316e3b..000000000
--- a/src/xenia/cpu/instrument.cc
+++ /dev/null
@@ -1,114 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#include "xenia/cpu/instrument.h"
-
-#include "xenia/memory.h"
-#include "xenia/cpu/function.h"
-#include "xenia/cpu/processor.h"
-
-namespace xe {
-namespace cpu {
-
-Instrument::Instrument(Processor* processor)
-    : processor_(processor),
-      memory_(processor->memory()),
-      is_attached_(false) {}
-
-Instrument::~Instrument() {
-  if (is_attached_) {
-    Detach();
-  }
-}
-
-bool Instrument::Attach() {
-  if (is_attached_) {
-    return false;
-  }
-  // runtime->AttachInstrument(this);
-  is_attached_ = true;
-  return true;
-}
-
-bool Instrument::Detach() {
-  if (!is_attached_) {
-    return false;
-  }
-  is_attached_ = false;
-  // runtime->DetachInstrument(this);
-  return true;
-}
-
-FunctionInstrument::FunctionInstrument(Processor* processor, Function* function)
-    : Instrument(processor), target_(function) {}
-
-bool FunctionInstrument::Attach() {
-  if (!Instrument::Attach()) {
-    return false;
-  }
-
-  // Function impl attach:
-  // - add instrument to list
-  // JIT: transition to instrumented state
-  //      - rewrite enter/exit to jump to instrumentation thunk
-  //      - some sort of locking required?
-
-  return true;
-}
-
-bool FunctionInstrument::Detach() {
-  if (!Instrument::Detach()) {
-    return false;
-  }
-
-  //
-
-  return true;
-}
-
-void FunctionInstrument::Enter(ThreadState* thread_state) {
-  // ? Placement new? How to get instance type?
-}
-
-void FunctionInstrument::Exit(ThreadState* thread_state) {
-  //
-}
-
-MemoryInstrument::MemoryInstrument(Processor* processor, uint32_t address,
-                                   uint32_t end_address)
-    : Instrument(processor), address_(address), end_address_(end_address) {}
-
-bool MemoryInstrument::Attach() {
-  if (!Instrument::Attach()) {
-    return false;
-  }
-
-  // TODO(benvanik): protect memory page, catch exception
-  // https://github.com/frida/frida-gum/blob/master/gum/gummemoryaccessmonitor.c
-
-  return true;
-}
-
-bool MemoryInstrument::Detach() {
-  if (!Instrument::Detach()) {
-    return false;
-  }
-
-  //
-
-  return true;
-}
-
-void MemoryInstrument::Access(ThreadState* thread_state, uint32_t address,
-                              AccessType type) {
-  // TODO(benvanik): get thread local instance
-}
-
-}  // namespace cpu
-}  // namespace xe
diff --git a/src/xenia/cpu/instrument.h b/src/xenia/cpu/instrument.h
deleted file mode 100644
index 156e90168..000000000
--- a/src/xenia/cpu/instrument.h
+++ /dev/null
@@ -1,142 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2014 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#ifndef XENIA_CPU_INSTRUMENT_H_
-#define XENIA_CPU_INSTRUMENT_H_
-
-#include <cstdint>
-
-namespace xe {
-namespace cpu {
-
-class Function;
-class Memory;
-class Processor;
-class ThreadState;
-
-class Instrument {
- public:
-  Instrument(Processor* processor);
-  virtual ~Instrument();
-
-  Processor* processor() const { return processor_; }
-  Memory* memory() const { return memory_; }
-  bool is_attached() const { return is_attached_; }
-
-  virtual bool Attach();
-  virtual bool Detach();
-
- private:
-  Processor* processor_;
-  Memory* memory_;
-  bool is_attached_;
-};
-
-class FunctionInstrument : public Instrument {
- public:
-  FunctionInstrument(Processor* processor, Function* function);
-  virtual ~FunctionInstrument() {}
-
-  Function* target() const { return target_; }
-
-  virtual bool Attach();
-  virtual bool Detach();
-
- public:
-  void Enter(ThreadState* thread_state);
-  void Exit(ThreadState* thread_state);
-
- protected:
-  class Instance {
-   public:
-    Instance(FunctionInstrument* instrument) : instrument_(instrument) {}
-    virtual ~Instance() {}
-
-    FunctionInstrument* instrument() const { return instrument_; }
-
-    virtual void OnEnter(ThreadState* thread_state) = 0;
-    virtual void OnExit(ThreadState* thread_state) = 0;
-
-    // TODO(benvanik): utilities:
-    //     Log(...)
-    //     DebugBreak(type)
-    //     GetArg(N)/GetReturn()/SetReturn(V) ?
-    //     CallSelf()
-    //     Call(target_fn/address)
-    //     Return(opt_value)
-
-   private:
-    FunctionInstrument* instrument_;
-  };
-
- private:
-  Function* target_;
-};
-
-class MemoryInstrument : public Instrument {
- public:
-  MemoryInstrument(Processor* processor, uint32_t address,
-                   uint32_t end_address);
-  virtual ~MemoryInstrument() {}
-
-  uint64_t address() const { return address_; }
-  uint64_t end_address() const { return end_address_; }
-
-  virtual bool Attach();
-  virtual bool Detach();
-
- public:
-  enum AccessType {
-    ACCESS_READ = (1 << 1),
-    ACCESS_WRITE = (1 << 2),
-  };
-  void Access(ThreadState* thread_state, uint32_t address, AccessType type);
-
- protected:
-  class Instance {
-   public:
-    Instance(MemoryInstrument* instrument) : instrument_(instrument) {}
-    virtual ~Instance() {}
-
-    MemoryInstrument* instrument() const { return instrument_; }
-
-    virtual void OnAccess(ThreadState* thread_state, uint32_t address,
-                          AccessType type) = 0;
-
-   private:
-    MemoryInstrument* instrument_;
-  };
-
- private:
-  uint32_t address_;
-  uint32_t end_address_;
-};
-
-// ThreadInstrument
-//   (v Detach())
-//   ThreadInstrumentInstance:
-//     instrument()
-//     v OnCreate(context, state_ptr)
-//     v OnStart(context, state_ptr)
-//     v OnResume(context, state_ptr)
-//     v OnSuspend(context, state_ptr)
-//     v OnExit(context, state_ptr)
-
-// ModuleInstrument
-//   (v Detach())
-//   ModuleInstrumentInstance:
-//     instrument()
-//     v OnLoad(context)
-//     v OnUnload(context)
-//     // get proc address?
-
-}  // namespace cpu
-}  // namespace xe
-
-#endif  // XENIA_CPU_INSTRUMENT_H_
diff --git a/src/xenia/cpu/module.cc b/src/xenia/cpu/module.cc
index 8bf30e68d..63ef2c4f5 100644
--- a/src/xenia/cpu/module.cc
+++ b/src/xenia/cpu/module.cc
@@ -26,12 +26,12 @@ Module::~Module() = default;
 
 bool Module::ContainsAddress(uint32_t address) { return true; }
 
-SymbolInfo* Module::LookupSymbol(uint32_t address, bool wait) {
+Symbol* Module::LookupSymbol(uint32_t address, bool wait) {
   lock_.lock();
   const auto it = map_.find(address);
-  SymbolInfo* symbol_info = it != map_.end() ? it->second : nullptr;
-  if (symbol_info) {
-    if (symbol_info->status() == SymbolStatus::kDeclaring) {
+  Symbol* symbol = it != map_.end() ? it->second : nullptr;
+  if (symbol) {
+    if (symbol->status() == Symbol::Status::kDeclaring) {
       // Some other thread is declaring the symbol - wait.
       if (wait) {
         do {
@@ -39,133 +39,130 @@ SymbolInfo* Module::LookupSymbol(uint32_t address, bool wait) {
           // TODO(benvanik): sleep for less time?
           xe::threading::Sleep(std::chrono::microseconds(100));
           lock_.lock();
-        } while (symbol_info->status() == SymbolStatus::kDeclaring);
+        } while (symbol->status() == Symbol::Status::kDeclaring);
       } else {
         // Immediate request, just return.
-        symbol_info = nullptr;
+        symbol = nullptr;
       }
     }
   }
   lock_.unlock();
-  return symbol_info;
+  return symbol;
 }
 
-SymbolStatus Module::DeclareSymbol(SymbolType type, uint32_t address,
-                                   SymbolInfo** out_symbol_info) {
-  *out_symbol_info = nullptr;
+Symbol::Status Module::DeclareSymbol(Symbol::Type type, uint32_t address,
+                                     Symbol** out_symbol) {
+  *out_symbol = nullptr;
   lock_.lock();
   auto it = map_.find(address);
-  SymbolInfo* symbol_info = it != map_.end() ? it->second : nullptr;
-  SymbolStatus status;
-  if (symbol_info) {
+  Symbol* symbol = it != map_.end() ? it->second : nullptr;
+  Symbol::Status status;
+  if (symbol) {
     // If we exist but are the wrong type, die.
-    if (symbol_info->type() != type) {
+    if (symbol->type() != type) {
       lock_.unlock();
-      return SymbolStatus::kFailed;
+      return Symbol::Status::kFailed;
     }
     // If we aren't ready yet spin and wait.
-    if (symbol_info->status() == SymbolStatus::kDeclaring) {
+    if (symbol->status() == Symbol::Status::kDeclaring) {
       // Still declaring, so spin.
       do {
         lock_.unlock();
         // TODO(benvanik): sleep for less time?
         xe::threading::Sleep(std::chrono::microseconds(100));
         lock_.lock();
-      } while (symbol_info->status() == SymbolStatus::kDeclaring);
+      } while (symbol->status() == Symbol::Status::kDeclaring);
     }
-    status = symbol_info->status();
+    status = symbol->status();
   } else {
     // Create and return for initialization.
     switch (type) {
-      case SymbolType::kFunction:
-        symbol_info = new FunctionInfo(this, address);
+      case Symbol::Type::kFunction:
+        symbol = CreateFunction(address).release();
         break;
-      case SymbolType::kVariable:
-        symbol_info = new VariableInfo(this, address);
+      case Symbol::Type::kVariable:
+        symbol = new Symbol(Symbol::Type::kVariable, this, address);
         break;
     }
-    map_[address] = symbol_info;
-    list_.emplace_back(symbol_info);
-    status = SymbolStatus::kNew;
+    map_[address] = symbol;
+    list_.emplace_back(symbol);
+    status = Symbol::Status::kNew;
   }
   lock_.unlock();
-  *out_symbol_info = symbol_info;
+  *out_symbol = symbol;
 
   // Get debug info from providers, if this is new.
-  if (status == SymbolStatus::kNew) {
+  if (status == Symbol::Status::kNew) {
     // TODO(benvanik): lookup in map data/dwarf/etc?
   }
 
   return status;
 }
 
-SymbolStatus Module::DeclareFunction(uint32_t address,
-                                     FunctionInfo** out_symbol_info) {
-  SymbolInfo* symbol_info;
-  SymbolStatus status =
-      DeclareSymbol(SymbolType::kFunction, address, &symbol_info);
-  *out_symbol_info = (FunctionInfo*)symbol_info;
+Symbol::Status Module::DeclareFunction(uint32_t address,
+                                       Function** out_function) {
+  Symbol* symbol;
+  Symbol::Status status =
+      DeclareSymbol(Symbol::Type::kFunction, address, &symbol);
+  *out_function = static_cast<Function*>(symbol);
   return status;
 }
 
-SymbolStatus Module::DeclareVariable(uint32_t address,
-                                     VariableInfo** out_symbol_info) {
-  SymbolInfo* symbol_info;
-  SymbolStatus status =
-      DeclareSymbol(SymbolType::kVariable, address, &symbol_info);
-  *out_symbol_info = (VariableInfo*)symbol_info;
+Symbol::Status Module::DeclareVariable(uint32_t address, Symbol** out_symbol) {
+  Symbol::Status status =
+      DeclareSymbol(Symbol::Type::kVariable, address, out_symbol);
   return status;
 }
 
-SymbolStatus Module::DefineSymbol(SymbolInfo* symbol_info) {
+Symbol::Status Module::DefineSymbol(Symbol* symbol) {
   lock_.lock();
-  SymbolStatus status;
-  if (symbol_info->status() == SymbolStatus::kDeclared) {
+  Symbol::Status status;
+  if (symbol->status() == Symbol::Status::kDeclared) {
     // Declared but undefined, so request caller define it.
-    symbol_info->set_status(SymbolStatus::kDefining);
-    status = SymbolStatus::kNew;
-  } else if (symbol_info->status() == SymbolStatus::kDefining) {
+    symbol->set_status(Symbol::Status::kDefining);
+    status = Symbol::Status::kNew;
+  } else if (symbol->status() == Symbol::Status::kDefining) {
     // Still defining, so spin.
     do {
       lock_.unlock();
       // TODO(benvanik): sleep for less time?
       xe::threading::Sleep(std::chrono::microseconds(100));
       lock_.lock();
-    } while (symbol_info->status() == SymbolStatus::kDefining);
-    status = symbol_info->status();
+    } while (symbol->status() == Symbol::Status::kDefining);
+    status = symbol->status();
   } else {
-    status = symbol_info->status();
+    status = symbol->status();
   }
   lock_.unlock();
   return status;
 }
 
-SymbolStatus Module::DefineFunction(FunctionInfo* symbol_info) {
-  return DefineSymbol((SymbolInfo*)symbol_info);
+Symbol::Status Module::DefineFunction(Function* symbol) {
+  return DefineSymbol((Symbol*)symbol);
 }
 
-SymbolStatus Module::DefineVariable(VariableInfo* symbol_info) {
-  return DefineSymbol((SymbolInfo*)symbol_info);
+Symbol::Status Module::DefineVariable(Symbol* symbol) {
+  return DefineSymbol((Symbol*)symbol);
 }
 
-void Module::ForEachFunction(std::function<void(FunctionInfo*)> callback) {
+void Module::ForEachFunction(std::function<void(Function*)> callback) {
   std::lock_guard<xe::mutex> guard(lock_);
-  for (auto& symbol_info : list_) {
-    if (symbol_info->type() == SymbolType::kFunction) {
-      FunctionInfo* info = static_cast<FunctionInfo*>(symbol_info.get());
+  for (auto& symbol : list_) {
+    if (symbol->type() == Symbol::Type::kFunction) {
+      Function* info = static_cast<Function*>(symbol.get());
       callback(info);
     }
   }
 }
 
 void Module::ForEachSymbol(size_t start_index, size_t end_index,
-                           std::function<void(SymbolInfo*)> callback) {
+                           std::function<void(Symbol*)> callback) {
   std::lock_guard<xe::mutex> guard(lock_);
   start_index = std::min(start_index, list_.size());
   end_index = std::min(end_index, list_.size());
   for (size_t i = start_index; i <= end_index; ++i) {
-    auto& symbol_info = list_[i];
-    callback(symbol_info.get());
+    auto& symbol = list_[i];
+    callback(symbol.get());
   }
 }
 
@@ -223,19 +220,19 @@ bool Module::ReadMap(const char* file_name) {
 
     if (type_str == "f") {
       // Function.
-      FunctionInfo* fn_info;
-      if (!processor_->LookupFunctionInfo(this, address, &fn_info)) {
+      auto function = processor_->LookupFunction(this, address);
+      if (!function) {
         continue;
       }
       // Don't overwrite names we've set elsewhere.
-      if (fn_info->name().empty()) {
+      if (function->name().empty()) {
         // If it's a mangled C++ name (?name@...) just use the name.
         // TODO(benvanik): better demangling, or leave it to clients.
         /*if (name[0] == '?') {
           size_t at = name.find('@');
           name = name.substr(1, at - 1);
         }*/
-        fn_info->set_name(name.c_str());
+        function->set_name(name.c_str());
       }
     } else {
       // Variable.
diff --git a/src/xenia/cpu/module.h b/src/xenia/cpu/module.h
index 517c59557..c933668d5 100644
--- a/src/xenia/cpu/module.h
+++ b/src/xenia/cpu/module.h
@@ -17,13 +17,13 @@
 #include <vector>
 
 #include "xenia/base/mutex.h"
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/function.h"
+#include "xenia/cpu/symbol.h"
 #include "xenia/memory.h"
 
 namespace xe {
 namespace cpu {
 
-class Function;
 class Processor;
 
 class Module {
@@ -37,36 +37,36 @@ class Module {
 
   virtual bool ContainsAddress(uint32_t address);
 
-  SymbolInfo* LookupSymbol(uint32_t address, bool wait = true);
-  virtual SymbolStatus DeclareFunction(uint32_t address,
-                                       FunctionInfo** out_symbol_info);
-  virtual SymbolStatus DeclareVariable(uint32_t address,
-                                       VariableInfo** out_symbol_info);
+  Symbol* LookupSymbol(uint32_t address, bool wait = true);
+  virtual Symbol::Status DeclareFunction(uint32_t address,
+                                         Function** out_function);
+  virtual Symbol::Status DeclareVariable(uint32_t address, Symbol** out_symbol);
 
-  SymbolStatus DefineFunction(FunctionInfo* symbol_info);
-  SymbolStatus DefineVariable(VariableInfo* symbol_info);
+  Symbol::Status DefineFunction(Function* symbol);
+  Symbol::Status DefineVariable(Symbol* symbol);
 
-  void ForEachFunction(std::function<void(FunctionInfo*)> callback);
+  void ForEachFunction(std::function<void(Function*)> callback);
   void ForEachSymbol(size_t start_index, size_t end_index,
-                     std::function<void(SymbolInfo*)> callback);
+                     std::function<void(Symbol*)> callback);
   size_t QuerySymbolCount();
 
   bool ReadMap(const char* file_name);
 
- private:
-  SymbolStatus DeclareSymbol(SymbolType type, uint32_t address,
-                             SymbolInfo** out_symbol_info);
-  SymbolStatus DefineSymbol(SymbolInfo* symbol_info);
-
  protected:
-  Processor* processor_;
-  Memory* memory_;
+  virtual std::unique_ptr<Function> CreateFunction(uint32_t address) = 0;
+
+  Processor* processor_ = nullptr;
+  Memory* memory_ = nullptr;
 
  private:
+  Symbol::Status DeclareSymbol(Symbol::Type type, uint32_t address,
+                               Symbol** out_symbol);
+  Symbol::Status DefineSymbol(Symbol* symbol);
+
   // TODO(benvanik): replace with a better data structure.
   xe::mutex lock_;
-  std::unordered_map<uint32_t, SymbolInfo*> map_;
-  std::vector<std::unique_ptr<SymbolInfo>> list_;
+  std::unordered_map<uint32_t, Symbol*> map_;
+  std::vector<std::unique_ptr<Symbol>> list_;
 };
 
 }  // namespace cpu
diff --git a/src/xenia/cpu/processor.cc b/src/xenia/cpu/processor.cc
index 3435660e2..d8852cd39 100644
--- a/src/xenia/cpu/processor.cc
+++ b/src/xenia/cpu/processor.cc
@@ -42,6 +42,11 @@ class BuiltinModule : public Module {
     return (address & 0xFFFFFFF0) == 0xFFFFFFF0;
   }
 
+ protected:
+  std::unique_ptr<Function> CreateFunction(uint32_t address) override {
+    return std::unique_ptr<Function>(new BuiltinFunction(this, address));
+  }
+
  private:
   std::string name_;
 };
@@ -142,20 +147,22 @@ std::vector<Module*> Processor::GetModules() {
   return clone;
 }
 
-FunctionInfo* Processor::DefineBuiltin(const std::string& name,
-                                       FunctionInfo::BuiltinHandler handler,
-                                       void* arg0, void* arg1) {
+Function* Processor::DefineBuiltin(const std::string& name,
+                                   BuiltinFunction::Handler handler, void* arg0,
+                                   void* arg1) {
   uint32_t address = next_builtin_address_;
   next_builtin_address_ += 4;
 
-  FunctionInfo* fn_info;
-  builtin_module_->DeclareFunction(address, &fn_info);
-  fn_info->set_end_address(address + 4);
-  fn_info->set_name(name);
-  fn_info->SetupBuiltin(handler, arg0, arg1);
-  fn_info->set_status(SymbolStatus::kDeclared);
+  Function* function;
+  builtin_module_->DeclareFunction(address, &function);
+  function->set_end_address(address + 4);
+  function->set_name(name);
 
-  return fn_info;
+  auto builtin_function = static_cast<BuiltinFunction*>(function);
+  builtin_function->SetupBuiltin(handler, arg0, arg1);
+
+  function->set_status(Symbol::Status::kDeclared);
+  return function;
 }
 
 Function* Processor::QueryFunction(uint32_t address) {
@@ -170,40 +177,36 @@ std::vector<Function*> Processor::FindFunctionsWithAddress(uint32_t address) {
   return entry_table_.FindWithAddress(address);
 }
 
-bool Processor::ResolveFunction(uint32_t address, Function** out_function) {
-  *out_function = nullptr;
+Function* Processor::ResolveFunction(uint32_t address) {
   Entry* entry;
   Entry::Status status = entry_table_.GetOrCreate(address, &entry);
   if (status == Entry::STATUS_NEW) {
     // Needs to be generated. We have the 'lock' on it and must do so now.
 
     // Grab symbol declaration.
-    FunctionInfo* symbol_info;
-    if (!LookupFunctionInfo(address, &symbol_info)) {
-      return false;
+    auto function = LookupFunction(address);
+    if (!function) {
+      return nullptr;
     }
 
-    if (!DemandFunction(symbol_info, &entry->function)) {
+    if (!DemandFunction(function)) {
       entry->status = Entry::STATUS_FAILED;
-      return false;
+      return nullptr;
     }
-    entry->end_address = symbol_info->end_address();
+    entry->function = function;
+    entry->end_address = function->end_address();
     status = entry->status = Entry::STATUS_READY;
   }
   if (status == Entry::STATUS_READY) {
     // Ready to use.
-    *out_function = entry->function;
-    return true;
+    return entry->function;
   } else {
     // Failed or bad state.
-    return false;
+    return nullptr;
   }
 }
 
-bool Processor::LookupFunctionInfo(uint32_t address,
-                                   FunctionInfo** out_symbol_info) {
-  *out_symbol_info = nullptr;
-
+Function* Processor::LookupFunction(uint32_t address) {
   // TODO(benvanik): fast reject invalid addresses/log errors.
 
   // Find the module that contains the address.
@@ -221,64 +224,57 @@ bool Processor::LookupFunctionInfo(uint32_t address,
   }
   if (!code_module) {
     // No module found that could contain the address.
-    return false;
+    return nullptr;
   }
 
-  return LookupFunctionInfo(code_module, address, out_symbol_info);
+  return LookupFunction(code_module, address);
 }
 
-bool Processor::LookupFunctionInfo(Module* module, uint32_t address,
-                                   FunctionInfo** out_symbol_info) {
+Function* Processor::LookupFunction(Module* module, uint32_t address) {
   // Atomic create/lookup symbol in module.
   // If we get back the NEW flag we must declare it now.
-  FunctionInfo* symbol_info = nullptr;
-  SymbolStatus symbol_status = module->DeclareFunction(address, &symbol_info);
-  if (symbol_status == SymbolStatus::kNew) {
+  Function* function = nullptr;
+  auto symbol_status = module->DeclareFunction(address, &function);
+  if (symbol_status == Symbol::Status::kNew) {
     // Symbol is undeclared, so declare now.
-    if (!frontend_->DeclareFunction(symbol_info)) {
-      symbol_info->set_status(SymbolStatus::kFailed);
-      return false;
+    assert_true(function->is_guest());
+    if (!frontend_->DeclareFunction(static_cast<GuestFunction*>(function))) {
+      function->set_status(Symbol::Status::kFailed);
+      return nullptr;
     }
-    symbol_info->set_status(SymbolStatus::kDeclared);
+    function->set_status(Symbol::Status::kDeclared);
   }
-
-  *out_symbol_info = symbol_info;
-  return true;
+  return function;
 }
 
-bool Processor::DemandFunction(FunctionInfo* symbol_info,
-                               Function** out_function) {
-  *out_function = nullptr;
-
+bool Processor::DemandFunction(Function* function) {
   // Lock function for generation. If it's already being generated
   // by another thread this will block and return DECLARED.
-  Module* module = symbol_info->module();
-  SymbolStatus symbol_status = module->DefineFunction(symbol_info);
-  if (symbol_status == SymbolStatus::kNew) {
+  auto module = function->module();
+  auto symbol_status = module->DefineFunction(function);
+  if (symbol_status == Symbol::Status::kNew) {
     // Symbol is undefined, so define now.
-    Function* function = nullptr;
-    if (!frontend_->DefineFunction(symbol_info, debug_info_flags_, &function)) {
-      symbol_info->set_status(SymbolStatus::kFailed);
+    assert_true(function->is_guest());
+    if (!frontend_->DefineFunction(static_cast<GuestFunction*>(function),
+                                   debug_info_flags_)) {
+      function->set_status(Symbol::Status::kFailed);
       return false;
     }
-    symbol_info->set_function(function);
 
     // Before we give the symbol back to the rest, let the debugger know.
     if (debugger_) {
-      debugger_->OnFunctionDefined(symbol_info, function);
+      debugger_->OnFunctionDefined(function);
     }
 
-    symbol_info->set_status(SymbolStatus::kDefined);
-    symbol_status = symbol_info->status();
+    function->set_status(Symbol::Status::kDefined);
+    symbol_status = function->status();
   }
 
-  if (symbol_status == SymbolStatus::kFailed) {
+  if (symbol_status == Symbol::Status::kFailed) {
     // Symbol likely failed.
     return false;
   }
 
-  *out_function = symbol_info->function();
-
   return true;
 }
 
@@ -286,8 +282,8 @@ bool Processor::Execute(ThreadState* thread_state, uint32_t address) {
   SCOPE_profile_cpu_f("cpu");
 
   // Attempt to get the function.
-  Function* fn;
-  if (!ResolveFunction(address, &fn)) {
+  auto function = ResolveFunction(address);
+  if (!function) {
     // Symbol not found in any module.
     XELOGCPU("Execute(%.8X): failed to find function", address);
     return false;
@@ -305,7 +301,7 @@ bool Processor::Execute(ThreadState* thread_state, uint32_t address) {
   context->lr = 0xBCBCBCBC;
 
   // Execute the function.
-  auto result = fn->Call(thread_state, uint32_t(context->lr));
+  auto result = function->Call(thread_state, uint32_t(context->lr));
 
   context->lr = previous_lr;
   context->r[1] += 64 + 112;
diff --git a/src/xenia/cpu/processor.h b/src/xenia/cpu/processor.h
index a5ef6da5c..356450d6d 100644
--- a/src/xenia/cpu/processor.h
+++ b/src/xenia/cpu/processor.h
@@ -69,17 +69,16 @@ class Processor {
   std::vector<Module*> GetModules();
 
   Module* builtin_module() const { return builtin_module_; }
-  FunctionInfo* DefineBuiltin(const std::string& name,
-                              FunctionInfo::BuiltinHandler handler, void* arg0,
-                              void* arg1);
+  Function* DefineBuiltin(const std::string& name,
+                          BuiltinFunction::Handler handler, void* arg0,
+                          void* arg1);
 
   Function* QueryFunction(uint32_t address);
   std::vector<Function*> FindFunctionsWithAddress(uint32_t address);
 
-  bool LookupFunctionInfo(uint32_t address, FunctionInfo** out_symbol_info);
-  bool LookupFunctionInfo(Module* module, uint32_t address,
-                          FunctionInfo** out_symbol_info);
-  bool ResolveFunction(uint32_t address, Function** out_function);
+  Function* LookupFunction(uint32_t address);
+  Function* LookupFunction(Module* module, uint32_t address);
+  Function* ResolveFunction(uint32_t address);
 
   bool Execute(ThreadState* thread_state, uint32_t address);
   uint64_t Execute(ThreadState* thread_state, uint32_t address, uint64_t args[],
@@ -89,7 +88,7 @@ class Processor {
   void LowerIrql(Irql old_value);
 
  private:
-  bool DemandFunction(FunctionInfo* symbol_info, Function** out_function);
+  bool DemandFunction(Function* function);
 
   Memory* memory_ = nullptr;
   debug::Debugger* debugger_ = nullptr;
diff --git a/src/xenia/cpu/raw_module.cc b/src/xenia/cpu/raw_module.cc
index e36ce2fb7..72b7d03a0 100644
--- a/src/xenia/cpu/raw_module.cc
+++ b/src/xenia/cpu/raw_module.cc
@@ -12,6 +12,8 @@
 #include "xenia/base/filesystem.h"
 #include "xenia/base/platform.h"
 #include "xenia/base/string.h"
+#include "xenia/cpu/function.h"
+#include "xenia/cpu/processor.h"
 
 namespace xe {
 namespace cpu {
@@ -60,5 +62,10 @@ bool RawModule::ContainsAddress(uint32_t address) {
   return address >= low_address_ && address < high_address_;
 }
 
+std::unique_ptr<Function> RawModule::CreateFunction(uint32_t address) {
+  return std::unique_ptr<Function>(
+      processor_->backend()->CreateGuestFunction(this, address));
+}
+
 }  // namespace cpu
 }  // namespace xe
diff --git a/src/xenia/cpu/raw_module.h b/src/xenia/cpu/raw_module.h
index d141661b8..543ae6c93 100644
--- a/src/xenia/cpu/raw_module.h
+++ b/src/xenia/cpu/raw_module.h
@@ -28,6 +28,9 @@ class RawModule : public Module {
 
   bool ContainsAddress(uint32_t address) override;
 
+ protected:
+  std::unique_ptr<Function> CreateFunction(uint32_t address) override;
+
  private:
   std::string name_;
   uint32_t base_address_;
diff --git a/src/xenia/cpu/stack_walker.h b/src/xenia/cpu/stack_walker.h
index e8b00326d..061dd4e5d 100644
--- a/src/xenia/cpu/stack_walker.h
+++ b/src/xenia/cpu/stack_walker.h
@@ -13,7 +13,7 @@
 #include <memory>
 #include <string>
 
-#include "xenia/cpu/symbol_info.h"
+#include "xenia/cpu/function.h"
 
 namespace xe {
 namespace cpu {
@@ -49,7 +49,7 @@ struct StackFrame {
     } host_symbol;
     // Contains symbol information for kGuest frames.
     struct {
-      FunctionInfo* function_info;
+      Function* function;
     } guest_symbol;
   };
 };
diff --git a/src/xenia/cpu/stack_walker_win.cc b/src/xenia/cpu/stack_walker_win.cc
index a9550c910..536079265 100644
--- a/src/xenia/cpu/stack_walker_win.cc
+++ b/src/xenia/cpu/stack_walker_win.cc
@@ -205,19 +205,21 @@ class Win32StackWalker : public StackWalker {
       if (frame.host_pc >= code_cache_min_ && frame.host_pc < code_cache_max_) {
         // Guest symbol, so we can look it up quickly in the code cache.
         frame.type = StackFrame::Type::kGuest;
-        auto function_info = code_cache_->LookupFunction(frame.host_pc);
-        if (function_info) {
-          frame.guest_symbol.function_info = function_info;
+        auto function = code_cache_->LookupFunction(frame.host_pc);
+        if (function) {
+          frame.guest_symbol.function = function;
           // Figure out where in guest code we are by looking up the
           // displacement in x64 from the JIT'ed code start to the PC.
-          uint32_t host_displacement =
-              uint32_t(frame.host_pc) -
-              uint32_t(uint64_t(function_info->function()->machine_code()));
-          auto entry =
-              function_info->function()->LookupCodeOffset(host_displacement);
-          frame.guest_pc = entry->source_offset;
+          if (function->is_guest()) {
+            auto guest_function = static_cast<GuestFunction*>(function);
+            uint32_t host_displacement =
+                uint32_t(frame.host_pc) -
+                uint32_t(uint64_t(guest_function->machine_code()));
+            auto entry = guest_function->LookupCodeOffset(host_displacement);
+            frame.guest_pc = entry->source_offset;
+          }
         } else {
-          frame.guest_symbol.function_info = nullptr;
+          frame.guest_symbol.function = nullptr;
         }
       } else {
         // Host symbol, which means either emulator or system.
diff --git a/src/xenia/cpu/symbol.h b/src/xenia/cpu/symbol.h
new file mode 100644
index 000000000..f0f367e9e
--- /dev/null
+++ b/src/xenia/cpu/symbol.h
@@ -0,0 +1,62 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_CPU_SYMBOL_INFO_H_
+#define XENIA_CPU_SYMBOL_INFO_H_
+
+#include <cstdint>
+#include <string>
+
+namespace xe {
+namespace cpu {
+
+class Module;
+
+class Symbol {
+ public:
+  enum class Type {
+    kFunction,
+    kVariable,
+  };
+
+  enum class Status {
+    kNew,
+    kDeclaring,
+    kDeclared,
+    kDefining,
+    kDefined,
+    kFailed,
+  };
+
+  Symbol(Type type, Module* module, uint32_t address)
+      : type_(type), module_(module), address_(address) {}
+  virtual ~Symbol() = default;
+
+  Type type() const { return type_; }
+  Module* module() const { return module_; }
+  Status status() const { return status_; }
+  void set_status(Status value) { status_ = value; }
+  uint32_t address() const { return address_; }
+
+  const std::string& name() const { return name_; }
+  void set_name(const std::string& value) { name_ = value; }
+
+ protected:
+  Type type_ = Type::kVariable;
+  Module* module_ = nullptr;
+  Status status_ = Status::kDefining;
+  uint32_t address_ = 0;
+
+  std::string name_;
+};
+
+}  // namespace cpu
+}  // namespace xe
+
+#endif  // XENIA_CPU_SYMBOL_INFO_H_
diff --git a/src/xenia/cpu/symbol_info.cc b/src/xenia/cpu/symbol_info.cc
deleted file mode 100644
index b004b4c57..000000000
--- a/src/xenia/cpu/symbol_info.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2013 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#include "xenia/cpu/symbol_info.h"
-
-#include <cstring>
-
-namespace xe {
-namespace cpu {
-
-SymbolInfo::SymbolInfo(SymbolType type, Module* module, uint32_t address)
-    : type_(type),
-      module_(module),
-      status_(SymbolStatus::kDefining),
-      address_(address),
-      name_("") {}
-
-SymbolInfo::~SymbolInfo() = default;
-
-FunctionInfo::FunctionInfo(Module* module, uint32_t address)
-    : SymbolInfo(SymbolType::kFunction, module, address),
-      end_address_(0),
-      behavior_(FunctionBehavior::kDefault),
-      function_(nullptr) {
-  std::memset(&extern_info_, 0, sizeof(extern_info_));
-}
-
-FunctionInfo::~FunctionInfo() = default;
-
-void FunctionInfo::SetupBuiltin(BuiltinHandler handler, void* arg0,
-                                void* arg1) {
-  behavior_ = FunctionBehavior::kBuiltin;
-  builtin_info_.handler = handler;
-  builtin_info_.arg0 = arg0;
-  builtin_info_.arg1 = arg1;
-}
-
-void FunctionInfo::SetupExtern(ExternHandler handler) {
-  behavior_ = FunctionBehavior::kExtern;
-  extern_info_.handler = handler;
-}
-
-VariableInfo::VariableInfo(Module* module, uint32_t address)
-    : SymbolInfo(SymbolType::kVariable, module, address) {}
-
-VariableInfo::~VariableInfo() = default;
-
-}  // namespace cpu
-}  // namespace xe
diff --git a/src/xenia/cpu/symbol_info.h b/src/xenia/cpu/symbol_info.h
deleted file mode 100644
index 67e66eb0f..000000000
--- a/src/xenia/cpu/symbol_info.h
+++ /dev/null
@@ -1,122 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2013 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#ifndef XENIA_CPU_SYMBOL_INFO_H_
-#define XENIA_CPU_SYMBOL_INFO_H_
-
-#include <cstdint>
-#include <string>
-
-#include "xenia/cpu/frontend/ppc_context.h"
-
-namespace xe {
-namespace cpu {
-
-class Function;
-class Module;
-
-enum class SymbolType {
-  kFunction,
-  kVariable,
-};
-
-enum class SymbolStatus {
-  kNew,
-  kDeclaring,
-  kDeclared,
-  kDefining,
-  kDefined,
-  kFailed,
-};
-
-class SymbolInfo {
- public:
-  SymbolInfo(SymbolType type, Module* module, uint32_t address);
-  virtual ~SymbolInfo();
-
-  SymbolType type() const { return type_; }
-  Module* module() const { return module_; }
-  SymbolStatus status() const { return status_; }
-  void set_status(SymbolStatus value) { status_ = value; }
-  uint32_t address() const { return address_; }
-
-  const std::string& name() const { return name_; }
-  void set_name(const std::string& value) { name_ = value; }
-
- protected:
-  SymbolType type_;
-  Module* module_;
-  SymbolStatus status_;
-  uint32_t address_;
-
-  std::string name_;
-};
-
-enum class FunctionBehavior {
-  kDefault = 0,
-  kProlog,
-  kEpilog,
-  kEpilogReturn,
-  kBuiltin,
-  kExtern,
-};
-
-class FunctionInfo : public SymbolInfo {
- public:
-  FunctionInfo(Module* module, uint32_t address);
-  ~FunctionInfo() override;
-
-  bool has_end_address() const { return end_address_ > 0; }
-  uint32_t end_address() const { return end_address_; }
-  void set_end_address(uint32_t value) { end_address_ = value; }
-
-  FunctionBehavior behavior() const { return behavior_; }
-  void set_behavior(FunctionBehavior value) { behavior_ = value; }
-
-  Function* function() const { return function_; }
-  void set_function(Function* value) { function_ = value; }
-
-  typedef void (*BuiltinHandler)(frontend::PPCContext* ppc_context, void* arg0,
-                                 void* arg1);
-  void SetupBuiltin(BuiltinHandler handler, void* arg0, void* arg1);
-  BuiltinHandler builtin_handler() const { return builtin_info_.handler; }
-  void* builtin_arg0() const { return builtin_info_.arg0; }
-  void* builtin_arg1() const { return builtin_info_.arg1; }
-
-  typedef void (*ExternHandler)(frontend::PPCContext* ppc_context,
-                                kernel::KernelState* kernel_state);
-  void SetupExtern(ExternHandler handler);
-  ExternHandler extern_handler() const { return extern_info_.handler; }
-
- private:
-  uint32_t end_address_;
-  FunctionBehavior behavior_;
-  Function* function_;
-  union {
-    struct {
-      ExternHandler handler;
-    } extern_info_;
-    struct {
-      BuiltinHandler handler;
-      void* arg0;
-      void* arg1;
-    } builtin_info_;
-  };
-};
-
-class VariableInfo : public SymbolInfo {
- public:
-  VariableInfo(Module* module, uint32_t address);
-  ~VariableInfo() override;
-};
-
-}  // namespace cpu
-}  // namespace xe
-
-#endif  // XENIA_CPU_SYMBOL_INFO_H_
diff --git a/src/xenia/cpu/test_module.cc b/src/xenia/cpu/test_module.cc
index c93aba42b..7c117ee79 100644
--- a/src/xenia/cpu/test_module.cc
+++ b/src/xenia/cpu/test_module.cc
@@ -71,29 +71,34 @@ bool TestModule::ContainsAddress(uint32_t address) {
   return contains_address_(address);
 }
 
-SymbolStatus TestModule::DeclareFunction(uint32_t address,
-                                         FunctionInfo** out_symbol_info) {
-  SymbolStatus status = Module::DeclareFunction(address, out_symbol_info);
-  if (status == SymbolStatus::kNew) {
-    auto symbol_info = *out_symbol_info;
+std::unique_ptr<Function> TestModule::CreateFunction(uint32_t address) {
+  return std::unique_ptr<Function>(
+      processor_->backend()->CreateGuestFunction(this, address));
+}
+
+Symbol::Status TestModule::DeclareFunction(uint32_t address,
+                                           Function** out_function) {
+  Symbol::Status status = Module::DeclareFunction(address, out_function);
+  if (status == Symbol::Status::kNew) {
+    auto function = static_cast<GuestFunction*>(*out_function);
 
     // Reset() all caching when we leave.
     xe::make_reset_scope(compiler_);
     xe::make_reset_scope(assembler_);
 
     if (!generate_(*builder_.get())) {
-      symbol_info->set_status(SymbolStatus::kFailed);
-      return SymbolStatus::kFailed;
+      function->set_status(Symbol::Status::kFailed);
+      return Symbol::Status::kFailed;
     }
 
+    // Run optimization passes.
     compiler_->Compile(builder_.get());
 
-    Function* fn = nullptr;
-    assembler_->Assemble(symbol_info, builder_.get(), 0, nullptr, &fn);
+    // Assemble the function.
+    assembler_->Assemble(function, builder_.get(), 0, nullptr);
 
-    symbol_info->set_function(fn);
-    status = SymbolStatus::kDefined;
-    symbol_info->set_status(status);
+    status = Symbol::Status::kDefined;
+    function->set_status(status);
   }
   return status;
 }
diff --git a/src/xenia/cpu/test_module.h b/src/xenia/cpu/test_module.h
index c228a6884..dfce7b731 100644
--- a/src/xenia/cpu/test_module.h
+++ b/src/xenia/cpu/test_module.h
@@ -33,8 +33,11 @@ class TestModule : public Module {
 
   bool ContainsAddress(uint32_t address) override;
 
-  SymbolStatus DeclareFunction(uint32_t address,
-                               FunctionInfo** out_symbol_info) override;
+  Symbol::Status DeclareFunction(uint32_t address,
+                                 Function** out_symbol) override;
+
+ protected:
+  std::unique_ptr<Function> CreateFunction(uint32_t address) override;
 
  private:
   std::string name_;
diff --git a/src/xenia/cpu/testing/util.h b/src/xenia/cpu/testing/util.h
index 44b3eb11f..9db88dd10 100644
--- a/src/xenia/cpu/testing/util.h
+++ b/src/xenia/cpu/testing/util.h
@@ -65,8 +65,7 @@ class TestFunction {
   void Run(std::function<void(PPCContext*)> pre_call,
            std::function<void(PPCContext*)> post_call) {
     for (auto& processor : processors) {
-      xe::cpu::Function* fn;
-      processor->ResolveFunction(0x80000000, &fn);
+      auto fn = processor->ResolveFunction(0x80000000);
 
       uint32_t stack_size = 64 * 1024;
       uint32_t stack_address = memory_size - stack_size;
diff --git a/src/xenia/cpu/xex_module.cc b/src/xenia/cpu/xex_module.cc
index f16d54d29..6deb8e654 100644
--- a/src/xenia/cpu/xex_module.cc
+++ b/src/xenia/cpu/xex_module.cc
@@ -375,12 +375,12 @@ bool XexModule::SetupLibraryImports(const char* name,
       }
 
       // Setup a variable and define it.
-      VariableInfo* var_info;
+      Symbol* var_info;
       DeclareVariable(record_addr, &var_info);
       var_info->set_name(import_name.GetString());
-      var_info->set_status(SymbolStatus::kDeclared);
+      var_info->set_status(Symbol::Status::kDeclared);
       DefineVariable(var_info);
-      var_info->set_status(SymbolStatus::kDefined);
+      var_info->set_status(Symbol::Status::kDefined);
     } else if (record_type == 1) {
       // Thunk.
       if (kernel_export) {
@@ -389,10 +389,10 @@ bool XexModule::SetupLibraryImports(const char* name,
         import_name.AppendFormat("__%s_%.3X", libbasename.c_str(), ordinal);
       }
 
-      FunctionInfo* fn_info;
-      DeclareFunction(record_addr, &fn_info);
-      fn_info->set_end_address(record_addr + 16 - 4);
-      fn_info->set_name(import_name.GetString());
+      Function* function;
+      DeclareFunction(record_addr, &function);
+      function->set_end_address(record_addr + 16 - 4);
+      function->set_name(import_name.GetString());
 
       if (kernel_export) {
         // On load we have something like this in memory:
@@ -415,14 +415,14 @@ bool XexModule::SetupLibraryImports(const char* name,
         xe::store_and_swap<uint32_t>(p + 0x8, 0x60000000);
         xe::store_and_swap<uint32_t>(p + 0xC, 0x60000000);
 
-        FunctionInfo::ExternHandler handler = 0;
+        GuestFunction::ExternHandler handler = nullptr;
         if (kernel_export) {
           if (kernel_export->function_data.trampoline) {
-            handler = (FunctionInfo::ExternHandler)
+            handler = (GuestFunction::ExternHandler)
                           kernel_export->function_data.trampoline;
           } else {
             handler =
-                (FunctionInfo::ExternHandler)kernel_export->function_data.shim;
+                (GuestFunction::ExternHandler)kernel_export->function_data.shim;
           }
         } else {
           XELOGW("WARNING: Imported kernel function %s is unimplemented!",
@@ -430,7 +430,7 @@ bool XexModule::SetupLibraryImports(const char* name,
           handler = UndefinedImport;
         }
 
-        fn_info->SetupExtern(handler);
+        static_cast<GuestFunction*>(function)->SetupExtern(handler);
       } else if (user_export_addr) {
         // Rewrite PPC code to set r11 to the target address
         // So we'll have:
@@ -458,7 +458,7 @@ bool XexModule::SetupLibraryImports(const char* name,
         xe::store_and_swap<uint32_t>(p + 0xC, 0x60000000);
       }
 
-      fn_info->set_status(SymbolStatus::kDeclared);
+      function->set_status(Symbol::Status::kDeclared);
     } else {
       // Bad.
       assert_always();
@@ -472,6 +472,11 @@ bool XexModule::ContainsAddress(uint32_t address) {
   return address >= low_address_ && address < high_address_;
 }
 
+std::unique_ptr<Function> XexModule::CreateFunction(uint32_t address) {
+  return std::unique_ptr<Function>(
+      processor_->backend()->CreateGuestFunction(this, address));
+}
+
 bool XexModule::FindSaveRest() {
   // Special stack save/restore functions.
   // http://research.microsoft.com/en-us/um/redmond/projects/invisible/src/crt/md/ppc/xxx.s.htm
@@ -677,27 +682,27 @@ bool XexModule::FindSaveRest() {
     uint32_t address = gplr_start;
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__savegprlr_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_end_address(address + (31 - n) * 4 + 2 * 4);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_end_address(address + (31 - n) * 4 + 2 * 4);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagSaveGprLr;
-      symbol_info->set_behavior(FunctionBehavior::kProlog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kProlog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 4;
     }
     address = gplr_start + 20 * 4;
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__restgprlr_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_end_address(address + (31 - n) * 4 + 3 * 4);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_end_address(address + (31 - n) * 4 + 3 * 4);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagRestGprLr;
-      symbol_info->set_behavior(FunctionBehavior::kEpilogReturn);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kEpilogReturn);
+      function->set_status(Symbol::Status::kDeclared);
       address += 4;
     }
   }
@@ -705,27 +710,27 @@ bool XexModule::FindSaveRest() {
     uint32_t address = fpr_start;
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__savefpr_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_end_address(address + (31 - n) * 4 + 1 * 4);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_end_address(address + (31 - n) * 4 + 1 * 4);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagSaveFpr;
-      symbol_info->set_behavior(FunctionBehavior::kProlog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kProlog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 4;
     }
     address = fpr_start + (18 * 4) + (1 * 4);
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__restfpr_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_end_address(address + (31 - n) * 4 + 1 * 4);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_end_address(address + (31 - n) * 4 + 1 * 4);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagRestFpr;
-      symbol_info->set_behavior(FunctionBehavior::kEpilog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kEpilog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 4;
     }
   }
@@ -738,49 +743,49 @@ bool XexModule::FindSaveRest() {
     uint32_t address = vmx_start;
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__savevmx_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagSaveVmx;
-      symbol_info->set_behavior(FunctionBehavior::kProlog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kProlog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 2 * 4;
     }
     address += 4;
     for (int n = 64; n <= 127; n++) {
       snprintf(name, xe::countof(name), "__savevmx_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagSaveVmx;
-      symbol_info->set_behavior(FunctionBehavior::kProlog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kProlog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 2 * 4;
     }
     address = vmx_start + (18 * 2 * 4) + (1 * 4) + (64 * 2 * 4) + (1 * 4);
     for (int n = 14; n <= 31; n++) {
       snprintf(name, xe::countof(name), "__restvmx_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagRestVmx;
-      symbol_info->set_behavior(FunctionBehavior::kEpilog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kEpilog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 2 * 4;
     }
     address += 4;
     for (int n = 64; n <= 127; n++) {
       snprintf(name, xe::countof(name), "__restvmx_%d", n);
-      FunctionInfo* symbol_info;
-      DeclareFunction(address, &symbol_info);
-      symbol_info->set_name(name);
+      Function* function;
+      DeclareFunction(address, &function);
+      function->set_name(name);
       // TODO(benvanik): set type  fn->type = FunctionSymbol::User;
       // TODO(benvanik): set flags fn->flags |= FunctionSymbol::kFlagRestVmx;
-      symbol_info->set_behavior(FunctionBehavior::kEpilog);
-      symbol_info->set_status(SymbolStatus::kDeclared);
+      function->set_behavior(Function::Behavior::kEpilog);
+      function->set_status(Symbol::Status::kDeclared);
       address += 2 * 4;
     }
   }
diff --git a/src/xenia/cpu/xex_module.h b/src/xenia/cpu/xex_module.h
index 962dcaf64..dcd73c9d3 100644
--- a/src/xenia/cpu/xex_module.h
+++ b/src/xenia/cpu/xex_module.h
@@ -77,12 +77,14 @@ class XexModule : public xe::cpu::Module {
 
   bool ContainsAddress(uint32_t address) override;
 
+ protected:
+  std::unique_ptr<Function> CreateFunction(uint32_t address) override;
+
  private:
   bool SetupLibraryImports(const char* name,
                            const xex2_import_library* library);
   bool FindSaveRest();
 
- private:
   Processor* processor_ = nullptr;
   kernel::KernelState* kernel_state_ = nullptr;
   std::string name_;
diff --git a/src/xenia/debug/debug_server.cc b/src/xenia/debug/debug_server.cc
index 8f001435b..1ae2f35ff 100644
--- a/src/xenia/debug/debug_server.cc
+++ b/src/xenia/debug/debug_server.cc
@@ -308,10 +308,10 @@ bool DebugServer::ProcessPacket(const proto::Packet* packet) {
           frame_body->host_function_address = frame.host_symbol.address;
           frame_body->guest_pc = frame.guest_pc;
           frame_body->guest_function_address = 0;
-          auto function_info = frame.guest_symbol.function_info;
-          if (frame.type == cpu::StackFrame::Type::kGuest && function_info) {
-            frame_body->guest_function_address = function_info->address();
-            std::strncpy(frame_body->name, function_info->name().c_str(),
+          auto function = frame.guest_symbol.function;
+          if (frame.type == cpu::StackFrame::Type::kGuest && function) {
+            frame_body->guest_function_address = function->address();
+            std::strncpy(frame_body->name, function->name().c_str(),
                          xe::countof(frame_body->name));
           } else {
             std::strncpy(frame_body->name, frame.host_symbol.name,
diff --git a/src/xenia/debug/debugger.cc b/src/xenia/debug/debugger.cc
index f9c7a4f02..636b713a9 100644
--- a/src/xenia/debug/debugger.cc
+++ b/src/xenia/debug/debugger.cc
@@ -169,10 +169,9 @@ void Debugger::DumpThreadStacks() {
         XELOGI("  %.2lld %.16llX          %s", count - i - 1, frame.host_pc,
                frame.host_symbol.name);
       } else {
-        auto function_info = frame.guest_symbol.function_info;
+        auto function = frame.guest_symbol.function;
         XELOGI("  %.2lld %.16llX %.8X %s", count - i - 1, frame.host_pc,
-               frame.guest_pc,
-               function_info ? function_info->name().c_str() : "?");
+               frame.guest_pc, function ? function->name().c_str() : "?");
       }
     }
   }
@@ -190,12 +189,13 @@ int Debugger::AddBreakpoint(Breakpoint* breakpoint) {
   auto fns =
       emulator_->processor()->FindFunctionsWithAddress(breakpoint->address());
 
+  // TODO(benvanik): breakpoints.
   // Add.
-  for (auto fn : fns) {
-    if (fn->AddBreakpoint(breakpoint)) {
-      return 1;
-    }
-  }
+  // for (auto fn : fns) {
+  //  if (fn->AddBreakpoint(breakpoint)) {
+  //    return 1;
+  //  }
+  //}
 
   return 0;
 }
@@ -226,9 +226,10 @@ int Debugger::RemoveBreakpoint(Breakpoint* breakpoint) {
       emulator_->processor()->FindFunctionsWithAddress(breakpoint->address());
 
   // Remove.
-  for (auto fn : fns) {
+  // TODO(benvanik): breakpoints.
+  /*for (auto fn : fns) {
     fn->RemoveBreakpoint(breakpoint);
-  }
+  }*/
 
   return 0;
 }
@@ -322,31 +323,30 @@ void Debugger::OnThreadDestroyed(xe::kernel::XThread* thread) {
   // TODO(benvanik): notify transports.
 }
 
-void Debugger::OnFunctionDefined(cpu::FunctionInfo* symbol_info,
-                                 cpu::Function* function) {
+void Debugger::OnFunctionDefined(cpu::Function* function) {
+  // TODO(benvanik): breakpoints?
   // Man, I'd love not to take this lock.
-  std::vector<Breakpoint*> breakpoints;
-  {
-    std::lock_guard<std::recursive_mutex> lock(mutex_);
-    for (uint32_t address = symbol_info->address();
-         address <= symbol_info->end_address(); address += 4) {
-      auto range = breakpoints_.equal_range(address);
-      if (range.first == range.second) {
-        continue;
-      }
-      for (auto it = range.first; it != range.second; ++it) {
-        Breakpoint* breakpoint = it->second;
-        breakpoints.push_back(breakpoint);
-      }
-    }
-  }
-
-  if (breakpoints.size()) {
-    // Breakpoints to add!
-    for (auto breakpoint : breakpoints) {
-      function->AddBreakpoint(breakpoint);
-    }
-  }
+  // std::vector<Breakpoint*> breakpoints;
+  //{
+  //  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  //  for (uint32_t address = function->address();
+  //       address <= function->end_address(); address += 4) {
+  //    auto range = breakpoints_.equal_range(address);
+  //    if (range.first == range.second) {
+  //      continue;
+  //    }
+  //    for (auto it = range.first; it != range.second; ++it) {
+  //      Breakpoint* breakpoint = it->second;
+  //      breakpoints.push_back(breakpoint);
+  //    }
+  //  }
+  //}
+  // if (breakpoints.size()) {
+  //  // Breakpoints to add!
+  //  for (auto breakpoint : breakpoints) {
+  //    function->AddBreakpoint(breakpoint);
+  //  }
+  //}
 }
 
 void Debugger::OnBreakpointHit(xe::kernel::XThread* thread,
diff --git a/src/xenia/debug/debugger.h b/src/xenia/debug/debugger.h
index 68ac64bad..b52d51774 100644
--- a/src/xenia/debug/debugger.h
+++ b/src/xenia/debug/debugger.h
@@ -83,8 +83,7 @@ class Debugger {
   void OnThreadExit(xe::kernel::XThread* thread);
   void OnThreadDestroyed(xe::kernel::XThread* thread);
 
-  void OnFunctionDefined(cpu::FunctionInfo* symbol_info,
-                         cpu::Function* function);
+  void OnFunctionDefined(cpu::Function* function);
 
   void OnBreakpointHit(xe::kernel::XThread* thread, Breakpoint* breakpoint);