Emitting functions and SEH info for call stacks.

src/alloy/backend/x64/lir/lir_builder.cc

@@ -106,14 +106,21 @@ LIRInstr* LIRBuilder::last_instr() const {
   return NULL;
 }
 
-LIRLabel* LIRBuilder::NewLabel(bool local) {
+LIRLabel* LIRBuilder::NewLabel(const char* name, bool local) {
   LIRLabel* label = arena_->Alloc<LIRLabel>();
   label->next = label->prev = NULL;
   label->block = NULL;
   label->id = next_label_id_++;
-  label->name = NULL;
   label->local = local;
   label->tag = NULL;
+  if (!name) {
+    char label_name[32] = "l";
+    _itoa(label->id, label_name + 1, 10);
+    name = label_name;
+  }
+  size_t label_length = xestrlena(name);
+  label->name = (char*)arena_->Alloc(label_length + 1);
+  xe_copy_struct(label->name, name, label_length + 1);
   return label;
 }
 

src/alloy/backend/x64/lir/lir_builder.h

@@ -41,8 +41,8 @@ public:
   LIRBlock* current_block() const;
   LIRInstr* last_instr() const;
 
-  LIRLabel* NewLabel(bool local = false);
+  LIRLabel* NewLabel(const char* name = 0, bool local = false);
-  LIRLabel* NewLocalLabel() { return NewLabel(true); }
+  LIRLabel* NewLocalLabel() { return NewLabel(0, true); }
   void MarkLabel(LIRLabel* label, LIRBlock* block = 0);
 
   // TODO(benvanik): allocations

src/alloy/backend/x64/lowering/lowering_table.cc

@@ -55,12 +55,7 @@ int LoweringTable::Process(
   while (hir_block) {
     auto hir_label = hir_block->label_head;
     while (hir_label) {
-      auto lir_label = lir_builder->NewLabel();
+      auto lir_label = lir_builder->NewLabel(hir_label->name);
-      if (hir_label->name) {
-        size_t label_len = xestrlena(hir_label->name);
-        lir_label->name = (char*)lir_builder->arena()->Alloc(label_len + 1);
-        xe_copy_struct(lir_label->name, hir_label->name, label_len + 1);
-      }
       hir_label->tag = lir_label;
       hir_label = hir_label->next;
     }

src/alloy/backend/x64/x64_code_cache.cc

@@ -16,6 +16,40 @@ using namespace alloy::backend;
 using namespace alloy::backend::x64;
 
 
+namespace alloy {
+namespace backend {
+namespace x64 {
+
+class X64CodeChunk {
+public:
+  X64CodeChunk(size_t chunk_size);
+  ~X64CodeChunk();
+public:
+  X64CodeChunk* next;
+  size_t    capacity;
+  uint8_t*  buffer;
+  size_t    offset;
+
+  // Estimate of function sized use to determine initial table capacity.
+  const static uint32_t ESTIMATED_FN_SIZE = 512;
+  // Size of unwind info per function.
+  // TODO(benvanik): move this to emitter.
+  const static uint32_t UNWIND_INFO_SIZE = 4 + (2 * 1);
+
+  void*             fn_table_handle;
+  RUNTIME_FUNCTION* fn_table;
+  uint32_t          fn_table_count;
+  uint32_t          fn_table_capacity;
+
+  void AddTableEntry(uint8_t* code, size_t code_size);
+};
+
+
+}  // namespace x64
+}  // namespace backend
+}  // namespace alloy
+
+
 X64CodeCache::X64CodeCache(size_t chunk_size) :
     chunk_size_(chunk_size),
     head_chunk_(NULL), active_chunk_(NULL) {
@@ -40,6 +74,9 @@ int X64CodeCache::Initialize() {
 }
 
 void* X64CodeCache::PlaceCode(void* machine_code, size_t code_size) {
+  // Add unwind info into the allocation size. Keep things 16b aligned.
+  code_size += XEROUNDUP(X64CodeChunk::UNWIND_INFO_SIZE, 16);
+
   // Always move the code to land on 16b alignment. We do this by rounding up
   // to 16b so that all offsets are aligned.
   code_size = XEROUNDUP(code_size, 16);
@@ -51,20 +88,24 @@ void* X64CodeCache::PlaceCode(void* machine_code, size_t code_size) {
       auto next = active_chunk_->next;
       if (!next) {
         XEASSERT(code_size < chunk_size_); // need to support larger chunks
-        next = new CodeChunk(chunk_size_);
+        next = new X64CodeChunk(chunk_size_);
         active_chunk_->next = next;
       }
       active_chunk_ = next;
     }
   } else {
-    head_chunk_ = active_chunk_ = new CodeChunk(chunk_size_);
+    head_chunk_ = active_chunk_ = new X64CodeChunk(chunk_size_);
   }
 
-  void* final_address = active_chunk_->buffer + active_chunk_->offset;
+  uint8_t* final_address = active_chunk_->buffer + active_chunk_->offset;
   active_chunk_->offset += code_size;
 
+  // Add entry to fn table.
+  active_chunk_->AddTableEntry(final_address, code_size);
+
   UnlockMutex(lock_);
 
+  // Copy code.
   xe_copy_struct(final_address, machine_code, code_size);
 
   // This isn't needed on x64 (probably), but is convention.
@@ -72,17 +113,127 @@ void* X64CodeCache::PlaceCode(void* machine_code, size_t code_size) {
   return final_address;
 }
 
-X64CodeCache::CodeChunk::CodeChunk(size_t chunk_size) :
+X64CodeChunk::X64CodeChunk(size_t chunk_size) :
     next(NULL),
     capacity(chunk_size), buffer(0), offset(0) {
   buffer = (uint8_t*)VirtualAlloc(
       NULL, capacity,
       MEM_RESERVE | MEM_COMMIT,
       PAGE_EXECUTE_READWRITE);
+
+  fn_table_capacity = (uint32_t)XEROUNDUP(capacity / ESTIMATED_FN_SIZE, 16);
+  size_t table_size = fn_table_capacity * sizeof(RUNTIME_FUNCTION);
+  fn_table = (RUNTIME_FUNCTION*)xe_malloc(table_size);
+  fn_table_count = 0;
+  fn_table_handle = 0;
+  RtlAddGrowableFunctionTable(
+      &fn_table_handle,
+      fn_table,
+      fn_table_count,
+      fn_table_capacity,
+      (ULONG_PTR)buffer, (ULONG_PTR)buffer + capacity);
 }
 
-X64CodeCache::CodeChunk::~CodeChunk() {
+X64CodeChunk::~X64CodeChunk() {
+  if (fn_table_handle) {
+    RtlDeleteGrowableFunctionTable(fn_table_handle);
+  }
   if (buffer) {
     VirtualFree(buffer, 0, MEM_RELEASE);
   }
 }
+
+// http://msdn.microsoft.com/en-us/library/ssa62fwe.aspx
+namespace {
+typedef enum _UNWIND_OP_CODES {
+  UWOP_PUSH_NONVOL = 0, /* info == register number */
+  UWOP_ALLOC_LARGE,     /* no info, alloc size in next 2 slots */
+  UWOP_ALLOC_SMALL,     /* info == size of allocation / 8 - 1 */
+  UWOP_SET_FPREG,       /* no info, FP = RSP + UNWIND_INFO.FPRegOffset*16 */
+  UWOP_SAVE_NONVOL,     /* info == register number, offset in next slot */
+  UWOP_SAVE_NONVOL_FAR, /* info == register number, offset in next 2 slots */
+  UWOP_SAVE_XMM128,     /* info == XMM reg number, offset in next slot */
+  UWOP_SAVE_XMM128_FAR, /* info == XMM reg number, offset in next 2 slots */
+  UWOP_PUSH_MACHFRAME   /* info == 0: no error-code, 1: error-code */
+} UNWIND_CODE_OPS;
+
+typedef union _UNWIND_CODE {
+  struct {
+    uint8_t CodeOffset;
+    uint8_t UnwindOp : 4;
+    uint8_t OpInfo   : 4;
+  };
+  USHORT FrameOffset;
+} UNWIND_CODE, *PUNWIND_CODE;
+
+typedef struct _UNWIND_INFO {
+  uint8_t Version       : 3;
+  uint8_t Flags         : 5;
+  uint8_t SizeOfProlog;
+  uint8_t CountOfCodes;
+  uint8_t FrameRegister : 4;
+  uint8_t FrameOffset   : 4;
+  UNWIND_CODE UnwindCode[1];
+/*  UNWIND_CODE MoreUnwindCode[((CountOfCodes + 1) & ~1) - 1];
+*   union {
+*       OPTIONAL ULONG ExceptionHandler;
+*       OPTIONAL ULONG FunctionEntry;
+*   };
+*   OPTIONAL ULONG ExceptionData[]; */
+} UNWIND_INFO, *PUNWIND_INFO;
+}  // namespace
+
+void X64CodeChunk::AddTableEntry(uint8_t* code, size_t code_size) {
+  // NOTE: we assume a chunk lock.
+
+  if (fn_table_count + 1 > fn_table_capacity) {
+    // Table exhausted, need to realloc. If this happens a lot we should tune
+    // the table size to prevent this.
+    XELOGW("X64CodeCache growing FunctionTable - adjust ESTIMATED_FN_SIZE");
+    RtlDeleteGrowableFunctionTable(fn_table_handle);
+    size_t old_size = fn_table_capacity * sizeof(RUNTIME_FUNCTION);
+    size_t new_size = old_size * 2;
+    auto new_table = (RUNTIME_FUNCTION*)xe_realloc(fn_table, old_size, new_size);
+    XEASSERTNOTNULL(new_table);
+    if (!new_table) {
+      return;
+    }
+    fn_table = new_table;
+    fn_table_capacity *= 2;
+    RtlAddGrowableFunctionTable(
+        &fn_table_handle,
+        fn_table,
+        fn_table_count,
+        fn_table_capacity,
+        (ULONG_PTR)buffer, (ULONG_PTR)buffer + capacity);
+  }
+
+  // Allocate unwind data. We know we have space because we overallocated.
+  // This should be the tailing 16b with 16b alignment.
+  size_t unwind_info_offset = offset;
+  offset += UNWIND_INFO_SIZE;
+
+  // http://msdn.microsoft.com/en-us/library/ddssxxy8.aspx
+  UNWIND_INFO* unwind_info = (UNWIND_INFO*)(buffer + unwind_info_offset);
+  unwind_info->Version = 1;
+  unwind_info->Flags = 0;
+  unwind_info->SizeOfProlog = 4;
+  unwind_info->CountOfCodes = 1;
+  unwind_info->FrameRegister = 0;
+  unwind_info->FrameOffset = 0;
+
+  // http://msdn.microsoft.com/en-us/library/ck9asaa9.aspx
+  auto& code_0 = unwind_info->UnwindCode[0];
+  code_0.CodeOffset = 4; // end of instruction + 1 == offset of next instruction
+  code_0.UnwindOp = UWOP_ALLOC_SMALL;
+  code_0.OpInfo = 16;
+
+  // Add entry.
+  auto& fn_entry = fn_table[fn_table_count++];
+  fn_entry.BeginAddress = (DWORD)(code - buffer);
+  fn_entry.EndAddress = (DWORD)(fn_entry.BeginAddress + code_size);
+  fn_entry.UnwindData = unwind_info_offset;
+
+  // Notify the function table that it has new entries.
+  RtlGrowFunctionTable(fn_table_handle, fn_table_count);
+}

src/alloy/backend/x64/x64_code_cache.h

@@ -17,6 +17,7 @@ namespace alloy {
 namespace backend {
 namespace x64 {
 
+class X64CodeChunk;
 
 class X64CodeCache {
 public:
@@ -32,23 +33,11 @@ public:
   void* PlaceCode(void* machine_code, size_t code_size);
 
 private:
-  class CodeChunk {
+  const static size_t DEFAULT_CHUNK_SIZE = 4 * 1024 * 1024;
-  public:
+  Mutex*        lock_;
-    CodeChunk(size_t chunk_size);
+  size_t        chunk_size_;
-    ~CodeChunk();
+  X64CodeChunk* head_chunk_;
-  public:
+  X64CodeChunk* active_chunk_;
-    CodeChunk*  next;
-    size_t      capacity;
-    uint8_t*    buffer;
-    size_t      offset;
-  };
-
-private:
-  static const size_t DEFAULT_CHUNK_SIZE = 4 * 1024 * 1024;
-  Mutex*      lock_;
-  size_t      chunk_size_;
-  CodeChunk*  head_chunk_;
-  CodeChunk*  active_chunk_;
 };
 
 

src/alloy/backend/x64/x64_emitter.cc

@@ -40,6 +40,7 @@ public:
   void* Emplace(X64CodeCache* code_cache);
   int Emit(LIRBuilder* builder);
 private:
+  int EmitInstruction(LIRInstr* instr);
 };
 
 }  // namespace x64
@@ -100,8 +101,54 @@ void* XbyakGenerator::Emplace(X64CodeCache* code_cache) {
 }
 
 int XbyakGenerator::Emit(LIRBuilder* builder) {
-  //
+  // Function prolog.
-  xor(rax, rax);
+  // Must be 16b aligned.
+  // Windows is very strict about the form of this and the eiplog:
+  // http://msdn.microsoft.com/en-us/library/tawsa7cb.aspx
+  // TODO(benvanik): save off non-volatile registers so we can use them:
+  //     RBX, RBP, RDI, RSI, RSP, R12, R13, R14, R15
+  //     Only want to do this if we actually use them, though, otherwise
+  //     it just adds overhead.
+  const size_t stack_size = 16;
+  sub(rsp, stack_size);
+
+  // Body.
+  auto block = builder->first_block();
+  while (block) {
+    // Mark block labels.
+    auto label = block->label_head;
+    while (label) {
+      L(label->name);
+      label = label->next;
+    }
+
+    // Add instructions.
+    auto instr = block->instr_head;
+    while (instr) {
+      // Stash offset in debug info.
+      // TODO(benvanik): stash size_ value.
+
+      // Emit.
+      int result = EmitInstruction(instr);
+      if (result) {
+        return result;
+      }
+
+      instr = instr->next;
+    }
+
+    block = block->next;
+  }
+
+  // Function epilog.
+  L("epilog");
+  add(rsp, stack_size);
+  // TODO(benvanik): restore registers.
   ret();
+
+  return 0;
+}
+
+int XbyakGenerator::EmitInstruction(LIRInstr* instr) {
   return 0;
 }

xenia.gyp

@@ -210,6 +210,7 @@
                   'kernel32',
                   'user32',
                   'ole32',
+                  'ntdll',
                 ],
               }],
               ['OS == "mac"', {