+++ /dev/null
-// i386-signal.h - Catch runtime signals and turn them into exceptions
-// on an i386 based Linux system.
-
-/* Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation
-
- This file is part of libgcj.
-
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
-
-
-#ifndef JAVA_SIGNAL_H
-#define JAVA_SIGNAL_H 1
-
-#include <signal.h>
-#include <sys/syscall.h>
-
-#define HANDLE_SEGV 1
-#define HANDLE_FPE 1
-
-#define SIGNAL_HANDLER(_name) \
-static void _name (int _dummy)
-
-#define MAKE_THROW_FRAME(_exception) \
-do \
-{ \
- void **_p = (void **)&_dummy; \
- struct sigcontext_struct *_regs = (struct sigcontext_struct *)++_p; \
- \
- /* Advance the program counter so that it is after the start of the \
- instruction: the x86 exception handler expects \
- the PC to point to the instruction after a call. */ \
- _regs->eip += 2; \
- \
-} \
-while (0)
-
-#define HANDLE_DIVIDE_OVERFLOW \
-do \
-{ \
- void **_p = (void **)&_dummy; \
- struct sigcontext_struct *_regs = (struct sigcontext_struct *)++_p; \
- \
- register unsigned char *_eip = (unsigned char *)_regs->eip; \
- \
- /* According to the JVM spec, "if the dividend is the negative \
- * integer of the smallest magnitude and the divisor is -1, then \
- * overflow occurs and the result is equal to the dividend. Despite \
- * the overflow, no exception occurs". \
- \
- * We handle this by inspecting the instruction which generated the \
- * signal and advancing eip to point to the following instruction. \
- * As the instructions are variable length it is necessary to do a \
- * little calculation to figure out where the following instruction \
- * actually is. \
- \
- */ \
- \
- if (_eip[0] == 0xf7) \
- { \
- unsigned char _modrm = _eip[1]; \
- \
- if (_regs->eax == 0x80000000 \
- && ((_modrm >> 3) & 7) == 7) /* Signed divide */ \
- { \
- _regs->edx = 0; /* the remainder is zero */ \
- switch (_modrm >> 6) \
- { \
- case 0: \
- if ((_modrm & 7) == 5) \
- _eip += 4; \
- break; \
- case 1: \
- _eip += 1; \
- break; \
- case 2: \
- _eip += 4; \
- break; \
- case 3: \
- break; \
- } \
- _eip += 2; \
- _regs->eip = (unsigned long)_eip; \
- return; \
- } \
- else \
- { \
- /* Advance the program counter so that it is after the start \
- of the instruction: this is because the x86 exception \
- handler expects the PC to point to the instruction after a \
- call. */ \
- _regs->eip += 2; \
- } \
- } \
-} \
-while (0)
-
-/* We use old_kernel_sigaction here because we're calling the kernel
- directly rather than via glibc. The sigaction structure that the
- syscall uses is a different shape from the one in userland and not
- visible to us in a header file so we define it here. */
-
-struct old_i386_kernel_sigaction {
- void (*k_sa_handler) (int);
- unsigned long k_sa_mask;
- unsigned long k_sa_flags;
- void (*sa_restorer) (void);
-};
-
-#define INIT_SEGV \
-do \
- { \
- nullp = new java::lang::NullPointerException (); \
- struct old_i386_kernel_sigaction kact; \
- kact.k_sa_handler = catch_segv; \
- kact.k_sa_mask = 0; \
- kact.k_sa_flags = 0; \
- syscall (SYS_sigaction, SIGSEGV, &kact, NULL); \
- } \
-while (0)
-
-#define INIT_FPE \
-do \
- { \
- arithexception = new java::lang::ArithmeticException \
- (JvNewStringLatin1 ("/ by zero")); \
- struct old_i386_kernel_sigaction kact; \
- kact.k_sa_handler = catch_fpe; \
- kact.k_sa_mask = 0; \
- kact.k_sa_flags = 0; \
- syscall (SYS_sigaction, SIGFPE, &kact, NULL); \
- } \
-while (0)
-
-/* You might wonder why we use syscall(SYS_sigaction) in INIT_FPE
- * instead of the standard sigaction(). This is necessary because of
- * the shenanigans above where we increment the PC saved in the
- * context and then return. This trick will only work when we are
- * called _directly_ by the kernel, because linuxthreads wraps signal
- * handlers and its wrappers do not copy the sigcontext struct back
- * when returning from a signal handler. If we return from our divide
- * handler to a linuxthreads wrapper, we will lose the PC adjustment
- * we made and return to the faulting instruction again. Using
- * syscall(SYS_sigaction) causes our handler to be called directly
- * by the kernel, bypassing any wrappers.
-
- * Also, there is at the present time no unwind info in the
- * linuxthreads library's signal handlers and so we can't unwind
- * through them anyway.
-
- * Finally, the code that glibc uses to return from a signal handler
- * is subject to change. */
-
-#endif /* JAVA_SIGNAL_H */
-
projects / msp430-gcc.git / blobdiff