*((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
}
\f
+/* When single stepping, single_stepping holds the original instruction
+ * PC location. */
+unsigned int *single_stepping = NULL;
void
arch_do_displaced_inst(os_context_t *context, unsigned int orig_inst)
/* Put the original instruction back. */
*((char *)pc) = orig_inst & 0xff;
*((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
+
+ *context_eflags_addr(context) |= 0x100;
+
+ single_stepping = pc;
}
+
\f
void
sigtrap_handler(int signal, siginfo_t *info, void *void_context)
os_context_t *context = (os_context_t*)void_context;
unsigned int trap;
+ if (single_stepping && (signal==SIGTRAP))
+ {
+ *context_eflags_addr(context) ^= 0x100;
+
+ /* Re-install the breakpoint if possible. */
+ if (*os_context_pc_addr(context) == (int)single_stepping + 1) {
+ fprintf(stderr, "warning: couldn't reinstall breakpoint\n");
+ } else {
+ *((char *)single_stepping) = BREAKPOINT_INST; /* x86 INT3 */
+ *((char *)single_stepping+1) = trap_Breakpoint;
+ }
+
+ single_stepping = NULL;
+ return;
+ }
+
/* This is just for info in case the monitor wants to print an
* approximation. */
current_control_stack_pointer =
(lispobj *)*os_context_sp_addr(context);
+ /* FIXME: CMUCL puts the float control restoration code here.
+ Thus, it seems to me that single-stepping won't restore the
+ float control. Since SBCL currently doesn't support
+ single-stepping (as far as I can tell) this is somewhat moot,
+ but it might be worth either moving this code up or deleting
+ the single-stepping code entirely. -- CSR, 2002-07-15 */
#ifdef LISP_FEATURE_LINUX
os_restore_fp_control(context);
#endif