Copyright (C) 1996-2005, 2006, 2007, 2008
CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+ Copyright (C) 2009 Theobroma Systems Ltd.
This file is part of CACAO.
#include <stdint.h>
#include <stdlib.h>
+#include "vm/jit/x86_64/codegen.h"
#include "vm/jit/x86_64/md-abi.h"
#include "vm/vm.hpp"
#include "vm/jit/codegen-common.hpp"
+#include "vm/jit/executionstate.h"
#include "vm/jit/jit.hpp"
+#include "vm/jit/trap.hpp"
/* md_init *********************************************************************
}
+/**
+ * Decode the trap instruction at the given PC.
+ *
+ * @param trp information about trap to be filled
+ * @param sig signal number
+ * @param xpc exception PC
+ * @param es execution state of the machine
+ * @return true if trap was decoded successfully, false otherwise.
+ */
+bool md_trap_decode(trapinfo_t* trp, int sig, void* _xpc, executionstate_t* es)
+{
+ uint8_t* xpc = (uint8_t*) _xpc;
+
+#if 0
+ // Check for StackOverflowException.
+ threads_check_stackoverflow(sp);
+#endif
+
+ switch (sig) {
+ case TRAP_SIGFPE:
+ // Check for ArithmeticException.
+ trp->type = TRAP_ArithmeticException;
+ trp->value = 0;
+ return true;
+
+ case TRAP_SIGILL:
+ // Check for valid trap instruction.
+ if (patcher_is_valid_trap_instruction_at(xpc)) {
+ trp->type = TRAP_PATCHER;
+ trp->value = 0;
+ return true;
+ }
+ return false;
+
+ case TRAP_SIGSEGV:
+ {
+ // Get exception-throwing instruction.
+ uint8_t opc = M_ALD_MEM_GET_OPC(xpc);
+ uint8_t mod = M_ALD_MEM_GET_MOD(xpc);
+ uint8_t rm = M_ALD_MEM_GET_RM(xpc);
+
+ // Check for hardware exception, for values
+ // see emit_mov_mem_reg and emit_mem.
+ if ((opc == 0x8b) && (mod == 0) && (rm == 4)) {
+ int32_t d = M_ALD_MEM_GET_REG(xpc);
+ int32_t disp = M_ALD_MEM_GET_DISP(xpc);
+
+ // We use the exception type as load displacement.
+ trp->type = disp;
+ trp->value = es->intregs[d];
+ return true;
+ }
+
+ // Default case is a normal NullPointerException.
+ else {
+ trp->type = TRAP_NullPointerException;
+ trp->value = 0;
+ return true;
+ }
+ }
+
+ default:
+ return false;
+ }
+}
+
+
/* md_patch_replacement_point **************************************************
Patch the given replacement point.