* src/vm/jit/alpha/linux/md-os.c: Simplified signal handlers.

[cacao.git] / src / vm / jit / alpha / md.c

diff --git a/src/vm/jit/alpha/md.c b/src/vm/jit/alpha/md.c
index 9ad99b7474b6f982d1c66ea557be178a04f453a7..fd2e0d4ce9563646677c919dbfbdce7dbbd791f6 100644 (file)
--- a/src/vm/jit/alpha/md.c
+++ b/src/vm/jit/alpha/md.c
@@ -2,6 +2,7 @@
 
    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.
 
@@ -40,7 +41,7 @@ extern void ieee_set_fp_control(unsigned long fp_control);
 
 #include "vm/jit/asmpart.h"
 #include "vm/jit/jit.hpp"
-#include "vm/jit/trap.h"
+#include "vm/jit/trap.hpp"
 
 
 /* global variables ***********************************************************/
@@ -189,6 +190,64 @@ void *md_jit_method_patch_address(void *pv, void *ra, void *mptr)
 }
 
 
+/**
+ * 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)
+{
+       // Get the exception-throwing instruction.
+       uint32_t mcode = *((uint32_t*) xpc);
+
+       switch (sig) {
+       case TRAP_SIGILL:
+               // Check for valid trap instruction.
+               // TODO Check the whole instruction.
+               if (M_OP3_GET_Opcode(mcode) == 0x4) {
+                       trp->type  = TRAP_PATCHER;
+                       trp->value = 0;
+                       return true;
+               }
+               return false;
+
+       case TRAP_SIGSEGV:
+       {
+               // Retrieve base address of instruction.
+               int32_t   s1   = M_MEM_GET_Rb(mcode);
+               uintptr_t addr = es->intregs[s1];
+
+               // Check for special-load.
+               if (s1 == REG_ZERO) {
+                       int32_t d    = M_MEM_GET_Ra(mcode);
+                       int32_t disp = M_MEM_GET_Memory_disp(mcode);
+
+                       // We use the exception type as load displacement.
+                       trp->type  = disp;
+                       trp->value = es->intregs[d];
+                       return true;
+               }
+
+               // Check for implicit NullPointerException.
+               if (addr == 0) {
+                       trp->type  = TRAP_NullPointerException;
+                       trp->value = 0;
+                       return true;
+               }
+
+               return false;
+       }
+
+       default:
+               return false;
+       }
+}
+
+
 /* md_patch_replacement_point **************************************************
 
    Patch the given replacement point.