Improve positions recording for calls.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 567 matching lines @@
                    address :
                    (*redirector_)(address, fp_return);
     return answer;
   }
 
   void* address_;
 };
 
 
 // -----------------------------------------------------------------------------
+// Position recording support
+
+enum PositionRecordingType { FORCED_POSITION, NORMAL_POSITION };

[Søren Thygesen Gjesse, 2010/11/04 15:08:24]

Thanks for using an enum instead of a boolean.

+
+class PositionsRecorder BASE_EMBEDDED {
+ public:
+  explicit PositionsRecorder(Assembler* assembler)
+      : assembler_(assembler),
+        current_position_(RelocInfo::kNoPosition),
+        current_position_recording_type_(NORMAL_POSITION),
+        written_position_(RelocInfo::kNoPosition),
+        current_statement_position_(RelocInfo::kNoPosition),
+        written_statement_position_(RelocInfo::kNoPosition) { }
+
+  // Set current position to pos. If recording_type is FORCED_POSITION then
+  // WriteRecordedPositions will write this position even if it is equal to
+  // statement position previously written for another pc.
+  void RecordPosition(int pos,
+                      PositionRecordingType recording_type = NORMAL_POSITION);
+
+  // Set current statement position to pos.
+  void RecordStatementPosition(int pos);
+
+  // Write recorded positions to relocation information.
+  bool WriteRecordedPositions();
+
+  int current_position() const { return current_position_; }
+
+  int current_statement_position() const { return current_statement_position_; }
+
+ private:
+  Assembler* assembler_;
+
+  int current_position_;
+  PositionRecordingType current_position_recording_type_;
+  int written_position_;
+
+  int current_statement_position_;
+  int written_statement_position_;
+};
+
+
+class PreserveStatementPositionScope BASE_EMBEDDED {
+ public:
+  PreserveStatementPositionScope(PositionsRecorder* positions_recorder)
+      : positions_recorder_(positions_recorder),
+        statement_position_(positions_recorder->current_statement_position()) {}
+
+  ~PreserveStatementPositionScope() {
+    if (statement_position_ != RelocInfo::kNoPosition) {
+      positions_recorder_->RecordStatementPosition(statement_position_);
+    }
+  }
+
+ private:
+  PositionsRecorder* positions_recorder_;
+  int statement_position_;
+};
+
+
+// -----------------------------------------------------------------------------
 // Utility functions
 
 static inline bool is_intn(int x, int n)  {
   return -(1 << (n-1)) <= x && x < (1 << (n-1));
 }
 
 static inline bool is_int8(int x)  { return is_intn(x, 8); }
 static inline bool is_int16(int x)  { return is_intn(x, 16); }
 static inline bool is_int18(int x)  { return is_intn(x, 18); }
 static inline bool is_int24(int x)  { return is_intn(x, 24); }
@@ skipping 19 matching lines @@
   unsigned int num_bits_set;
   for (num_bits_set = 0; x; x >>= 1) {
     num_bits_set += x & 1;
   }
   return num_bits_set;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_