Implements catch on MIPS.

runtime/vm/stub_code_mips.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 "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 577 matching lines @@
   // GC marking, since it traverses any information between SP and
   // FP - kExitLinkOffsetInEntryFrame.
   // EntryFrame::SavedContext reads the context saved in this frame.
   __ lw(T1, Address(T2, Isolate::top_context_offset()));
 
   // The constants kSavedContextOffsetInEntryFrame and
   // kExitLinkOffsetInEntryFrame must be kept in sync with the code below.
   __ sw(T0, Address(SP, 1 * kWordSize));
   __ sw(T1, Address(SP, 0 * kWordSize));
 
-  // after the call, The stack pointer is restored to this location.
-  // Pushed A3, S0-7, S4, S5 = 11.
+  // After the call, The stack pointer is restored to this location.
+  // Pushed A3, S0-7, T0, T1 = 11.
   const intptr_t kSavedContextOffsetInEntryFrame = -11 * kWordSize;
 
   // Load arguments descriptor array into S4, which is passed to Dart code.
   __ lw(S4, Address(A1, VMHandles::kOffsetOfRawPtrInHandle));
 
   // Load number of arguments into S5.
   __ lw(T1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
   __ SmiUntag(T1);
 
   // Compute address of 'arguments array' data area into A2.
@@ skipping 35 matching lines @@
   __ lw(T1, Address(SP, 0 * kWordSize));
   __ lw(T0, Address(SP, 1 * kWordSize));
   __ sw(T1, Address(CTX, Isolate::top_context_offset()));
   __ sw(T0, Address(CTX, Isolate::top_exit_frame_info_offset()));
 
   // Restore C++ ABI callee-saved registers.
   for (int i = S0; i <= S7; i++) {
     Register r = static_cast<Register>(i);
     __ lw(r, Address(SP, (i - S0 + 3) * kWordSize));
   }
-  __ lw(A3, Address(SP));
+  __ lw(A3, Address(SP, 2 * kWordSize));
   __ addiu(SP, SP, Immediate((3 + kAbiPreservedCpuRegCount) * kWordSize));
 
   // Restore the frame pointer and return.
   __ LeaveStubFrame();
   __ Ret();
 }
 
 
 // Called for inline allocation of contexts.
 // Input:
@@ skipping 923 matching lines @@
 
 // Return the current stack pointer address, used to stack alignment
 // checks.
 void StubCode::GenerateGetStackPointerStub(Assembler* assembler) {
   __ Unimplemented("GetStackPointer Stub");
 }
 
 
 // Jump to the exception or error handler.
 // RA: return address.
 // A0: program_counter.

[regis, 2013/04/23 17:24:49]

V0?
You read from V0 in the code, but it seems strange to pass the first argument in
V0 and the following ones in A1, A2, and A3.

[zra, 2013/04/23 18:03:58]

You're right, V0 in the code should have been A0.

 // A1: stack_pointer.
 // A2: frame_pointer.
 // A3: error object.
 // SP: address of stacktrace object.
 // Does not return.
 void StubCode::GenerateJumpToExceptionHandlerStub(Assembler* assembler) {
-  ASSERT(kExceptionObjectReg == A0);
+  ASSERT(kExceptionObjectReg == V0);
   ASSERT(kStackTraceObjectReg == A1);
   __ mov(TMP1, A1);  // Stack pointer.
-  __ mov(RA, A0);  // Program counter.
-  __ mov(A0, A3);  // Exception object.
+  __ mov(RA, V0);  // Program counter.
+  __ mov(V0, A3);  // Exception object.
   __ lw(A1, Address(SP, 0));  // StackTrace object.
   __ mov(FP, A2);  // Frame_pointer.
   __ mov(SP, TMP1);  // Stack pointer.
   __ jr(RA);  // Jump to the exception handler code.
 }
 
 
 void StubCode::GenerateEqualityWithNullArgStub(Assembler* assembler) {
   __ Unimplemented("EqualityWithNullArg Stub");
 }
@@ skipping 122 matching lines @@
   __ Bind(&done);
   __ lw(T0, Address(SP, 0 * kWordSize));
   __ lw(T1, Address(SP, 1 * kWordSize));
   __ Ret();
   __ delay_slot()->addiu(SP, SP, Immediate(2 * kWordSize));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS