Bug 1071604 - Mechanisms for triggering the ARM simulator's REPL. r=mjrosenb

js/src/jit/arm/MacroAssembler-arm.cpp

@@ -3715,6 +3715,16 @@ MacroAssemblerARMCompat::breakpoint()
     as_bkpt();
 }
 
+void
+MacroAssemblerARMCompat::simulatorStop(const char* msg)
+{
+#if defined(JS_ARM_SIMULATOR)
+    JS_ASSERT(sizeof(char*) == 4);
+    writeInst(0xefffffff);
+    writeInst((int)msg);
+#endif
+}
+
 void
 MacroAssemblerARMCompat::ensureDouble(const ValueOperand &source, FloatRegister dest, Label *failure)
 {

js/src/jit/arm/MacroAssembler-arm.h

@@ -1451,6 +1451,11 @@ class MacroAssemblerARMCompat : public MacroAssemblerARM
     // Conditional breakpoint.
     void breakpoint(Condition cc);
 
+    // Trigger the simulator's interactive read-eval-print loop.
+    // The message will be printed at the stopping point.
+    // (On non-simulator builds, does nothing.)
+    void simulatorStop(const char* msg);
+
     void compareDouble(FloatRegister lhs, FloatRegister rhs);
     void branchDouble(DoubleCondition cond, FloatRegister lhs, FloatRegister rhs,
                       Label *label);

js/src/jit/arm/Simulator-arm.cpp

@@ -651,6 +651,7 @@ ReadLine(const char *prompt)
     return result;
 }
 
+// Observe that llvm-mc may have a different name on your system.  Make a symlink.
 static void
 DisassembleInstruction(uint32_t pc)
 {