Copies Simulator Debugger from ARM to MIPS.

runtime/vm/simulator_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <math.h>  // for isnan.
 #include <setjmp.h>
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
@@ skipping 275 matching lines @@
 void SimulatorDebugger::RedoBreakpoints() {
   if (sim_->break_pc_ != NULL) {
     sim_->break_pc_->SetInstructionBits(kSimulatorBreakpointInstr);
   }
 }
 
 
 void SimulatorDebugger::Debug() {
   intptr_t last_pc = -1;
   bool done = false;
+  bool decoded = true;
 
 #define COMMAND_SIZE 63
 #define ARG_SIZE 255
 
 #define STR(a) #a
 #define XSTR(a) STR(a)
 
   char cmd[COMMAND_SIZE + 1];
   char arg1[ARG_SIZE + 1];
   char arg2[ARG_SIZE + 1];
 
   // make sure to have a proper terminating character if reaching the limit
   cmd[COMMAND_SIZE] = 0;
   arg1[ARG_SIZE] = 0;
   arg2[ARG_SIZE] = 0;
 
   // Undo all set breakpoints while running in the debugger shell. This will
   // make them invisible to all commands.
   UndoBreakpoints();
 
   while (!done) {
     if (last_pc != sim_->get_pc()) {
       last_pc = sim_->get_pc();
-      Disassembler::Disassemble(last_pc, last_pc + Instr::kInstrSize);
+      decoded = Disassembler::Disassemble(last_pc, last_pc + Instr::kInstrSize);
     }
     char* line = ReadLine("sim> ");
     if (line == NULL) {
       break;
     } else {
       // Use sscanf to parse the individual parts of the command line. At the
       // moment no command expects more than two parameters.
       int args = SScanF(line,
                         "%" XSTR(COMMAND_SIZE) "s "
                         "%" XSTR(ARG_SIZE) "s "
                         "%" XSTR(ARG_SIZE) "s",
                         cmd, arg1, arg2);
       if ((strcmp(cmd, "h") == 0) || (strcmp(cmd, "help") == 0)) {
         OS::Print("c/cont -- continue execution\n"
                   "disasm -- disassemble instrs at current pc location\n"
                   "  other variants are:\n"
                   "    disasm <address>\n"
                   "    disasm <address> <number_of_instructions>\n"
                   "  by default 10 instrs are disassembled\n"
                   "del -- delete breakpoints\n"
                   "flags -- print flag values\n"
                   "gdb -- transfer control to gdb\n"
                   "h/help -- print this help string\n"
                   "break <address> -- set break point at specified address\n"
                   "p/print <reg or value or *addr> -- print integer value\n"
                   "pf/printfloat <sreg or *addr> -- print float value\n"
                   "pd/printdouble <dreg or *addr> -- print double value\n"
                   "po/printobject <*reg or *addr> -- print object\n"
                   "si/stepi -- single step an instruction\n"
-                  "unstop -- if current pc is a stop instr make it a nop\n");
+                  "unstop -- if current pc is a stop instr make it a nop\n"
+                  "q/quit -- Quit the debugger and exit the program\n");
+      } else if ((strcmp(cmd, "quit") == 0) || (strcmp(cmd, "q") == 0)) {
+        OS::Print("Quitting\n");
+        OS::Exit(0);
       } else if ((strcmp(cmd, "si") == 0) || (strcmp(cmd, "stepi") == 0)) {
-        sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
+        if (decoded) {
+          sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
+        } else {
+          OS::Print("Instruction could not be decoded. Stepping disabled.\n");
+        }
       } else if ((strcmp(cmd, "c") == 0) || (strcmp(cmd, "cont") == 0)) {
-        // Execute the one instruction we broke at with breakpoints disabled.
-        sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
-        // Leave the debugger shell.
-        done = true;
+        if (decoded) {
+          // Execute the one instruction we broke at with breakpoints disabled.
+          sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
+          // Leave the debugger shell.
+          done = true;
+        } else {
+          OS::Print("Instruction could not be decoded. Cannot continue.\n");
+        }
       } else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
         if (args == 2) {
           uint32_t value;
           if (GetValue(arg1, &value)) {
             OS::Print("%s: %u 0x%x\n", arg1, value, value);
           } else {
             OS::Print("%s unrecognized\n", arg1);
           }
         } else {
           OS::Print("print <reg or value or *addr>\n");
@@ skipping 2490 matching lines @@
   // isolate->ChangeStateToGeneratedCode();
   set_register(kExceptionObjectReg, bit_cast<int32_t>(object.raw()));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM)
 
 #endif  // defined TARGET_ARCH_ARM