Patch: FYI: Interpreter: SAVE_PC before resolve_pool_entry

[Bryce McKinlay]

Tom Tromey pointed out that the interpreter doesn't always save the PC 
before calling resolve_pool_entry, which can throw. Likewise, we arn't 
calling SAVE_PC before the divide operations which can throw 
ArithmeticException.

This patch rearranges the SAVE_PC sites to fix the problem. I'm checking 
it in to trunk.

Bryce


2006-07-13  Bryce McKinlay  <mckinlay@xxxxxxxxxx>

        * interpret.cc (_Jv_InterpMethod::compile): Add FIXME comment.
        (_Jv_InterpMethod::run): SAVE_PC before executing any instruction 
        using resolve_pool_entry, as it can throw. Likewise for div/rem ops
        that can throw ArithmeticException.

Index: interpret.cc
===================================================================
--- interpret.cc        (revision 115370)
+++ interpret.cc        (working copy)
@@ -776,6 +776,8 @@
       exc[i].start_pc.p = &insns[pc_mapping[exc[i].start_pc.i]];
       exc[i].end_pc.p = &insns[pc_mapping[exc[i].end_pc.i]];
       exc[i].handler_pc.p = &insns[pc_mapping[exc[i].handler_pc.i]];
+      // FIXME: resolve_pool_entry can throw - we shouldn't be doing this
+      // during compilation.
       jclass handler
        = (_Jv_Linker::resolve_pool_entry (defining_class,
                                             exc[i].handler_type.i)).clazz;
@@ -1139,6 +1141,7 @@
 
     insn_invokevirtual:        // 0xb6
       {
+       SAVE_PC();
        int index = GET2U ();
 
        /* _Jv_Linker::resolve_pool_entry returns immediately if the
@@ -1155,7 +1158,6 @@
        if (rmeth->method->accflags & Modifier::FINAL)
          {
            // We can't rely on NULLCHECK working if the method is final.
-           SAVE_PC();
            if (! sp[0].o)
              throw_null_pointer_exception ();
 
@@ -1182,13 +1184,13 @@
 #ifdef DIRECT_THREADED
     invokevirtual_resolved:
       {
+       SAVE_PC();
        rmeth = (_Jv_ResolvedMethod *) AVAL ();
        sp -= rmeth->stack_item_count;
 
        if (rmeth->method->accflags & Modifier::FINAL)
          {
            // We can't rely on NULLCHECK working if the method is final.
-           SAVE_PC();
            if (! sp[0].o)
              throw_null_pointer_exception ();
 
@@ -1207,8 +1209,6 @@
 
     perform_invoke:
       {
-        SAVE_PC();
-       
        /* here goes the magic again... */
        ffi_cif *cif = &rmeth->cif;
        ffi_raw *raw = (ffi_raw*) sp;
@@ -1358,6 +1358,7 @@
       // For direct threaded we have a separate 'ldc class' operation.
     insn_ldc_class:
       {
+       SAVE_PC();
        // We could rewrite the instruction at this point.
        int index = INTVAL ();
        jobject k = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
@@ -1826,6 +1827,7 @@
 
     insn_idiv:
       {
+       SAVE_PC();
        jint value2 = POPI();
        jint value1 = POPI();
        jint res = _Jv_divI (value1, value2);
@@ -1835,6 +1837,7 @@
 
     insn_ldiv:
       {
+       SAVE_PC();
        jlong value2 = POPL();
        jlong value1 = POPL();
        jlong res = _Jv_divJ (value1, value2);
@@ -1844,6 +1847,7 @@
 
     insn_fdiv:
       {
+       SAVE_PC();
        jfloat value2 = POPF();
        jfloat value1 = POPF();
        jfloat res = value1 / value2;
@@ -1862,6 +1866,7 @@
 
     insn_irem:
       {
+       SAVE_PC();
        jint value2 = POPI();
        jint value1 =  POPI();
        jint res = _Jv_remI (value1, value2);
@@ -1871,6 +1876,7 @@
 
     insn_lrem:
       {
+       SAVE_PC();
        jlong value2 = POPL();
        jlong value1 = POPL();
        jlong res = _Jv_remJ (value1, value2);
@@ -2539,6 +2545,7 @@
 
     insn_getfield:
       {
+       SAVE_PC();
        jint fieldref_index = GET2U ();
        _Jv_Linker::resolve_pool_entry (meth->defining_class, fieldref_index);
        _Jv_Field *field = pool_data[fieldref_index].field;
@@ -2653,6 +2660,7 @@
 
     insn_putstatic:
       {
+       SAVE_PC();
        jint fieldref_index = GET2U ();
        _Jv_Linker::resolve_pool_entry (meth->defining_class, fieldref_index);
        _Jv_Field *field = pool_data[fieldref_index].field;
@@ -2740,6 +2748,7 @@
 
     insn_putfield:
       {
+       SAVE_PC();
        jint fieldref_index = GET2U ();
        _Jv_Linker::resolve_pool_entry (meth->defining_class, fieldref_index);
        _Jv_Field *field = pool_data[fieldref_index].field;
@@ -2863,6 +2872,7 @@
 
     insn_invokespecial:
       {
+       SAVE_PC();
        int index = GET2U ();
 
        rmeth = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
@@ -2892,13 +2902,13 @@
 #ifdef DIRECT_THREADED
     invokespecial_resolved:
       {
+       SAVE_PC();
        rmeth = (_Jv_ResolvedMethod *) AVAL ();
        sp -= rmeth->stack_item_count;
        // We don't use NULLCHECK here because we can't rely on that
        // working for <init>.  So instead we do an explicit test.
        if (! sp[0].o)
          {
-           SAVE_PC();
            throw_null_pointer_exception ();
          }
        fun = (void (*)()) rmeth->method->ncode;
@@ -2908,6 +2918,7 @@
 
     insn_invokestatic:
       {
+       SAVE_PC();
        int index = GET2U ();
 
        rmeth = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
@@ -2929,6 +2940,7 @@
 #ifdef DIRECT_THREADED
     invokestatic_resolved:
       {
+       SAVE_PC();
        rmeth = (_Jv_ResolvedMethod *) AVAL ();
        sp -= rmeth->stack_item_count;
        fun = (void (*)()) rmeth->method->ncode;
@@ -2938,6 +2950,7 @@
 
     insn_invokeinterface:
       {
+       SAVE_PC();
        int index = GET2U ();
 
        rmeth = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
@@ -2969,6 +2982,7 @@
 #ifdef DIRECT_THREADED
     invokeinterface_resolved:
       {
+       SAVE_PC();
        rmeth = (_Jv_ResolvedMethod *) AVAL ();
        sp -= rmeth->stack_item_count;
        jobject rcv = sp[0].o;
@@ -2983,6 +2997,7 @@
 
     insn_new:
       {
+       SAVE_PC();
        int index = GET2U ();
        jclass klass = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
                                                          index)).clazz;
@@ -3021,6 +3036,7 @@
 
     insn_anewarray:
       {
+       SAVE_PC();
        int index = GET2U ();
        jclass klass = (_Jv_Linker::resolve_pool_entry (meth->defining_class,
                                                          index)).clazz;
@@ -3156,6 +3172,7 @@
 
     insn_multianewarray:
       {
+       SAVE_PC();
        int kind_index = GET2U ();
        int dim        = GET1U ();