Implemented missing pieces of the debugger for ARM

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 75 matching lines @@
 
 
 // -----------------------------------------------------------------------------
 // Implementation of RelocInfo
 
 const int RelocInfo::kApplyMask = 0;
 
 
 void RelocInfo::PatchCode(byte* instructions, int instruction_count) {
   // Patch the code at the current address with the supplied instructions.
-  UNIMPLEMENTED();
+  Instr* pc = reinterpret_cast<Instr*>(pc_);
+  Instr* instr = reinterpret_cast<Instr*>(instructions);
+  for (int i = 0; i < instruction_count; i++) {
+    *(pc + i) = *(instr + i);
+  }
+
+  // Indicate that code has changed.
+  CPU::FlushICache(pc_, instruction_count * Assembler::kInstrSize);
 }
 
 
 // Patch the code at the current PC with a call to the target address.
 // Additional guard instructions can be added if required.
 void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
   // Patch the code at the current address with a call to the target.
   UNIMPLEMENTED();
 }
 
@@ skipping 118 matching lines @@
 static const Instr kPopInstruction =
     al | 4 * B21 | 4 | LeaveCC | I | sp.code() * B16 | sp.code() * B12;
 // str(r, MemOperand(sp, 4, NegPreIndex), al) instruction (aka push(r))
 // register r is not encoded.
 static const Instr kPushRegPattern =
     al | B26 | 4 | NegPreIndex | sp.code() * B16;
 // ldr(r, MemOperand(sp, 4, PostIndex), al) instruction (aka pop(r))
 // register r is not encoded.
 static const Instr kPopRegPattern =
     al | B26 | L | 4 | PostIndex | sp.code() * B16;
+// mov lr, pc
+const Instr kMovLrPc = al | 13*B21 | pc.code() | lr.code() * B12;
+// ldr pc, [pc, #XXX]
+const Instr kLdrPCPattern = al | B26 | L | pc.code() * B16;
 
 // spare_buffer_
 static const int kMinimalBufferSize = 4*KB;
 static byte* spare_buffer_ = NULL;
 
 Assembler::Assembler(void* buffer, int buffer_size) {
   if (buffer == NULL) {
     // do our own buffer management
     if (buffer_size <= kMinimalBufferSize) {
       buffer_size = kMinimalBufferSize;
@@ skipping 1049 matching lines @@
       mov(dst, Operand(x.rn_), s, cond);
     else if ((am & U) == 0)  // negative indexing
       sub(dst, x.rn_, Operand(x.rm_, x.shift_op_, x.shift_imm_), s, cond);
     else
       add(dst, x.rn_, Operand(x.rm_, x.shift_op_, x.shift_imm_), s, cond);
   }
 }
 
 
 // Debugging
+void Assembler::RecordJSReturn() {
+  WriteRecordedPositions();
+  CheckBuffer();
+  RecordRelocInfo(RelocInfo::JS_RETURN);
+}
+
+
 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;
@@ skipping 66 matching lines @@
 
   // none of our relocation types are pc relative pointing outside the code
   // buffer nor pc absolute pointing inside the code buffer, so there is no need
   // to relocate any emitted relocation entries
 
   // relocate pending relocation entries
   for (int i = 0; i < num_prinfo_; i++) {
     RelocInfo& rinfo = prinfo_[i];
     ASSERT(rinfo.rmode() != RelocInfo::COMMENT &&
            rinfo.rmode() != RelocInfo::POSITION);
-    rinfo.set_pc(rinfo.pc() + pc_delta);
+    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::COMMENT && rmode <= RelocInfo::STATEMENT_POSITION) {
-    // adjust code for new modes
-    ASSERT(RelocInfo::IsComment(rmode) || RelocInfo::IsPosition(rmode));
+  if (rmode >= RelocInfo::JS_RETURN && rmode <= RelocInfo::STATEMENT_POSITION) {
+    // Adjust code for new modes
+    ASSERT(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);
   }
   if (rinfo.rmode() != RelocInfo::NONE) {
     // Don't record external references unless the heap will be serialized.
@@ skipping 73 matching lines @@
   // "Undefined instruction" as specified by A3.1 Instruction set encoding
   emit(0x03000000 | num_prinfo_);
 
   // Emit constant pool entries
   for (int i = 0; i < num_prinfo_; i++) {
     RelocInfo& rinfo = prinfo_[i];
     ASSERT(rinfo.rmode() != RelocInfo::COMMENT &&
            rinfo.rmode() != RelocInfo::POSITION &&
            rinfo.rmode() != RelocInfo::STATEMENT_POSITION);
     Instr instr = instr_at(rinfo.pc());
+
     // Instruction to patch must be a ldr/str [pc, #offset]
     // P and U set, B and W clear, Rn == pc, offset12 still 0
     ASSERT((instr & (7*B25 | P | U | B | W | 15*B16 | Off12Mask)) ==
            (2*B25 | P | U | pc.code()*B16));
     int delta = pc_ - rinfo.pc() - 8;
     ASSERT(delta >= -4);  // instr could be ldr pc, [pc, #-4] followed by targ32
     if (delta < 0) {
       instr &= ~U;
       delta = -delta;
     }
@@ skipping 10 matching lines @@
     bind(&after_pool);
   }
 
   // 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