More precise break points and stepping when debugging...

src/arm/assembler-arm.cc

 // 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 2022 matching lines @@
 
 
 // Debugging.
 void Assembler::RecordJSReturn() {
   WriteRecordedPositions();
   CheckBuffer();
   RecordRelocInfo(RelocInfo::JS_RETURN);
 }
 
 
+void Assembler::RecordDebugBreakSlot() {
+  WriteRecordedPositions();
+  CheckBuffer();
+  RecordRelocInfo(RelocInfo::DEBUG_BREAK_SLOT);
+}
+
+
 void Assembler::RecordComment(const char* msg) {
   if (FLAG_debug_code) {
     CheckBuffer();
     RecordRelocInfo(RelocInfo::COMMENT, reinterpret_cast<intptr_t>(msg));
   }
 }
 
 
 void Assembler::RecordPosition(int pos) {
   if (pos == RelocInfo::kNoPosition) return;
   ASSERT(pos >= 0);
   current_position_ = pos;
 }
 
 
 void Assembler::RecordStatementPosition(int pos) {
   if (pos == RelocInfo::kNoPosition) return;
   ASSERT(pos >= 0);
   current_statement_position_ = pos;
 }
 
 
-void Assembler::WriteRecordedPositions() {
+bool Assembler::WriteRecordedPositions() {
+  bool written = false;
+
   // Write the statement position if it is different from what was written last
   // time.
   if (current_statement_position_ != written_statement_position_) {
     CheckBuffer();
     RecordRelocInfo(RelocInfo::STATEMENT_POSITION, current_statement_position_);
     written_statement_position_ = current_statement_position_;
+    written = true;
   }
 
   // Write the position if it is different from what was written last time and
   // also different from the written statement position.
   if (current_position_ != written_position_ &&
       current_position_ != written_statement_position_) {
     CheckBuffer();
     RecordRelocInfo(RelocInfo::POSITION, current_position_);
     written_position_ = current_position_;
+    written = true;
   }
+
+  // Return whether something was written.
+  return written;
 }
 
 
 void Assembler::GrowBuffer() {
   if (!own_buffer_) FATAL("external code buffer is too small");
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
   if (buffer_size_ < 4*KB) {
     desc.buffer_size = 4*KB;
@@ skipping 36 matching lines @@
            rinfo.rmode() != RelocInfo::POSITION);
     if (rinfo.rmode() != RelocInfo::JS_RETURN) {
       rinfo.set_pc(rinfo.pc() + pc_delta);
     }
   }
 }
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
   RelocInfo rinfo(pc_, rmode, data);  // we do not try to reuse pool constants
-  if (rmode >= RelocInfo::JS_RETURN && rmode <= RelocInfo::STATEMENT_POSITION) {
+  if (rmode >= RelocInfo::JS_RETURN && rmode <= RelocInfo::DEBUG_BREAK_SLOT) {
     // Adjust code for new modes.
-    ASSERT(RelocInfo::IsJSReturn(rmode)
+    ASSERT(RelocInfo::IsDebugBreakSlot(rmode)
+           || RelocInfo::IsJSReturn(rmode)
            || RelocInfo::IsComment(rmode)
            || RelocInfo::IsPosition(rmode));
     // These modes do not need an entry in the constant pool.
   } else {
     ASSERT(num_prinfo_ < kMaxNumPRInfo);
     prinfo_[num_prinfo_++] = rinfo;
     // Make sure the constant pool is not emitted in place of the next
     // instruction for which we just recorded relocation info.
     BlockConstPoolBefore(pc_offset() + kInstrSize);
   }
@@ skipping 119 matching lines @@
 
   // Since a constant pool was just emitted, move the check offset forward by
   // the standard interval.
   next_buffer_check_ = pc_offset() + kCheckConstInterval;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM