[gcc.git] / libjava / include / dwarf2-signal.h

// dwarf2-signal.h - Catch runtime signals and turn them into exceptions.

/* Copyright (C) 2000, 2001  Free Software Foundation

   This file is part of libgcj.

   Use this file for a target for which the dwarf2 unwinder in libgcc
   can unwind through signal handlers.

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
#undef HANDLE_FPE

#define SIGNAL_HANDLER(_name)	\
static void _Jv_##_name (int, siginfo_t *_sip, void *_p)

class java::lang::Throwable;

// Unwind the stack to the point at which the signal was generated and
// then throw an exception.  With the dwarf2 unwinder we don't usually
// need to do anything, with some minor exceptions.

#ifdef __alpha__
#define MAKE_THROW_FRAME(_exception)					\
do									\
{									\
  /* Alpha either leaves PC pointing at a faulting instruction or the	\
   following instruction, depending on the signal.  SEGV always does	\
   the former, so we adjust the saved PC to point to the following	\
   instruction; this is what the handler in libgcc expects.  */		\
  struct sigcontext *_sc = (struct sigcontext *)_p;			\
  _sc->sc_pc += 4;							\
}									\
while (0)

#elif defined(__ia64__)

#define MAKE_THROW_FRAME(_exception)					\
do									\
{									\
  /* IA-64 either leaves PC pointing at a faulting instruction or the	\
   following instruction, depending on the signal.  SEGV always does	\
   the former, so we adjust the saved PC to point to the following	\
   instruction; this is what the handler in libgcc expects.  */		\
  /* Note that we are lying to the unwinder here, which expects the	\
   faulting pc, not pc+1.  But we claim the unwind information can't	\
   be changed by such a ld or st instruction, so it doesn't matter. */	\
  struct sigcontext *_sc = (struct sigcontext *)_p;			\
  _sc->sc_ip++;								\
}									\
while (0)
#elif defined(__sparc__)
/* We could do the unwind of the signal frame quickly by hand here like
   sparc-signal.h does under Solaris, but that makes debugging unwind
   failures almost impossible.  */
#if !defined(__arch64__)
#define MAKE_THROW_FRAME(_exception)					\
do									\
{									\
  /* Sparc-32 leaves PC pointing at a faulting instruction		\
   always.								\
   We advance the PC one instruction past the exception causing PC.	\
   This is done because FDEs are found with "context->ra - 1" in the	\
   unwinder.								\
   Also, the dwarf2 unwind machinery is going to add 8 to the		\
   PC it uses on Sparc.  So we adjust the PC here.  We do it here	\
   because we run once for such an exception, however the Sparc specific\
   unwind can run multiple times for the same exception and it would	\
   adjust the PC more than once resulting in a bogus value.  */		\
  struct sig_regs {							\
    unsigned int psr, pc, npc, y, u_regs[16];				\
  } *regp;								\
  unsigned int insn;							\
  __asm__ __volatile__("ld [%%i7 + 8], %0" : "=r" (insn));		\
  /* mov __NR_sigaction, %g1; Old signal stack layout */		\
  if (insn == 0x821020d8)						\
    regp = (struct sig_regs *) _sip;					\
  else									\
    /* mov __NR_rt_sigaction, %g1; New signal stack layout */		\
    regp = (struct sig_regs *) (_sip + 1);				\
  regp->pc = ((regp->pc + 4) - 8);					\
}									\
while (0)
#else
#define MAKE_THROW_FRAME(_exception)					\
do									\
{									\
  /* Sparc-64 leaves PC pointing at a faulting instruction		\
   always.								\
   We advance the PC one instruction past the exception causing PC.	\
   This is done because FDEs are found with "context->ra - 1" in the	\
   unwinder.								\
   Also, the dwarf2 unwind machinery is going to add 8 to the		\
   PC it uses on Sparc.  So we adjust the PC here.  We do it here	\
   because we run once for such an exception, however the Sparc specific\
   unwind can run multiple times for the same exception and it would	\
   adjust the PC more than once resulting in a bogus value.  */		\
  struct pt_regs {							\
    unsigned long u_regs[16];						\
    unsigned long tstate, tpc, tnpc;					\
    unsigned int y, fprs;						\
  } *regp = (struct pt_regs *) (_sip + 1);				\
  regp->tpc = ((regp->tpc + 4) - 8);					\
}									\
while (0)
#endif
#else
#define MAKE_THROW_FRAME(_exception)		\
do						\
{						\
  (void)_p;					\
}						\
while (0)
#endif

#if !(defined(__ia64__) || defined(__sparc__))
#define INIT_SEGV						\
do								\
  {								\
    nullp = new java::lang::NullPointerException ();    	\
    struct sigaction act;					\
    act.sa_sigaction = _Jv_catch_segv;      			\
    sigemptyset (&act.sa_mask);					\
    act.sa_flags = SA_SIGINFO;	       				\
    syscall (SYS_sigaction, SIGSEGV, &act, NULL);		\
  }								\
while (0)  

#define INIT_FPE						\
do								\
  { 								\
    arithexception = new java::lang::ArithmeticException 	\
      (JvNewStringLatin1 ("/ by zero"));			\
    struct sigaction act;					\
    act.sa_sigaction = _Jv_catch_fpe;				\
    sigemptyset (&act.sa_mask);					\
    act.sa_flags = SA_SIGINFO;		       			\
    syscall (SYS_sigaction, SIGFPE, &act, NULL);		\
  }								\
while (0)  

/* We use syscall(SYS_sigaction) in INIT_SEGV and INIT_FPE instead of
 * sigaction() because on some systems the pthreads wrappers for
 * signal handlers are not compiled with unwind information, so it's
 * not possible to unwind through them.  This is a problem that will
 * go away once all systems have pthreads libraries that are
 * compiled with full unwind info.  */

#else  /* __ia64__ || __sparc__ */

// FIXME: We shouldn't be using libc_sigaction here, since it should
// be glibc private.  But using syscall here would mean translating to
// the kernel's struct sigaction and argument sequence, which we
// shouldn't either.  The right solution is to call sigaction and to
// make sure that we can unwind correctly through the pthread signal
// wrapper.
extern "C" int __libc_sigaction (int __sig, 
		      __const struct sigaction *__restrict __act,
                      struct sigaction *__restrict __oact) throw ();

#define INIT_SEGV						\
do								\
  {								\
    nullp = new java::lang::NullPointerException ();    	\
    struct sigaction act;					\
    act.sa_sigaction = _Jv_catch_segv;      			\
    sigemptyset (&act.sa_mask);					\
    act.sa_flags = SA_SIGINFO;	       				\
    __libc_sigaction (SIGSEGV, &act, NULL);			\
  }								\
while (0)  

#define INIT_FPE						\
do								\
  { 								\
    arithexception = new java::lang::ArithmeticException 	\
      (JvNewStringLatin1 ("/ by zero"));			\
    struct sigaction act;					\
    act.sa_sigaction = _Jv_catch_fpe;				\
    sigemptyset (&act.sa_mask);					\
    act.sa_flags = SA_SIGINFO;		       			\
    __libc_sigaction (SIGFPE, &act, NULL);			\
  }								\
while (0)  
#endif /* __ia64__ || __sparc__ */
#endif /* JAVA_SIGNAL_H */
Commit	Line	Data
01936f3a AH	1	// dwarf2-signal.h - Catch runtime signals and turn them into exceptions.
	2
	3	/* Copyright (C) 2000, 2001 Free Software Foundation
	4
	5	This file is part of libgcj.
	6
c9bffcd5 AH	7	Use this file for a target for which the dwarf2 unwinder in libgcc
c9bffcd5 AH	8	can unwind through signal handlers.
01936f3a AH	9
	10	This software is copyrighted work licensed under the terms of the
	11	Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
	12	details. */
	13
	14	#ifndef JAVA_SIGNAL_H
	15	#define JAVA_SIGNAL_H 1
	16
	17	#include <signal.h>
	18	#include <sys/syscall.h>
	19
	20	#define HANDLE_SEGV 1
	21	#undef HANDLE_FPE
	22
	23	#define SIGNAL_HANDLER(_name) \
714708c8	24	static void _Jv_##_name (int, siginfo_t _sip, void _p)
01936f3a AH	25
	26	class java::lang::Throwable;
	27
	28	// Unwind the stack to the point at which the signal was generated and
c9bffcd5 AH	29	// then throw an exception. With the dwarf2 unwinder we don't usually
	30	// need to do anything, with some minor exceptions.
	31
	32	#ifdef __alpha__
	33	#define MAKE_THROW_FRAME(_exception) \
	34	do \
	35	{ \
	36	/* Alpha either leaves PC pointing at a faulting instruction or the \
	37	following instruction, depending on the signal. SEGV always does \
	38	the former, so we adjust the saved PC to point to the following \
	39	instruction; this is what the handler in libgcc expects. */ \
	40	struct sigcontext _sc = (struct sigcontext )_p; \
	41	_sc->sc_pc += 4; \
	42	} \
	43	while (0)
3cb20545 AH	44
	45	#elif defined(__ia64__)
	46
	47	#define MAKE_THROW_FRAME(_exception) \
	48	do \
	49	{ \
	50	/* IA-64 either leaves PC pointing at a faulting instruction or the \
	51	following instruction, depending on the signal. SEGV always does \
	52	the former, so we adjust the saved PC to point to the following \
	53	instruction; this is what the handler in libgcc expects. */ \
	54	/* Note that we are lying to the unwinder here, which expects the \
	55	faulting pc, not pc+1. But we claim the unwind information can't \
	56	be changed by such a ld or st instruction, so it doesn't matter. */ \
	57	struct sigcontext _sc = (struct sigcontext )_p; \
	58	_sc->sc_ip++; \
	59	} \
	60	while (0)
714708c8 DM	61	#elif defined(__sparc__)
	62	/* We could do the unwind of the signal frame quickly by hand here like
	63	sparc-signal.h does under Solaris, but that makes debugging unwind
	64	failures almost impossible. */
	65	#if !defined(__arch64__)
	66	#define MAKE_THROW_FRAME(_exception) \
	67	do \
	68	{ \
	69	/* Sparc-32 leaves PC pointing at a faulting instruction \
6ea53170 DM	70	always. \
	71	We advance the PC one instruction past the exception causing PC. \
	72	This is done because FDEs are found with "context->ra - 1" in the \
	73	unwinder. \
	74	Also, the dwarf2 unwind machinery is going to add 8 to the \
	75	PC it uses on Sparc. So we adjust the PC here. We do it here \
	76	because we run once for such an exception, however the Sparc specific\
	77	unwind can run multiple times for the same exception and it would \
	78	adjust the PC more than once resulting in a bogus value. */ \
714708c8 DM	79	struct sig_regs { \
	80	unsigned int psr, pc, npc, y, u_regs[16]; \
	81	} *regp; \
	82	unsigned int insn; \
	83	__asm__ __volatile__("ld [%%i7 + 8], %0" : "=r" (insn)); \
4bf01445	84	/* mov __NR_sigaction, %g1; Old signal stack layout */ \
714708c8 DM	85	if (insn == 0x821020d8) \
	86	regp = (struct sig_regs *) _sip; \
	87	else \
4bf01445	88	/* mov __NR_rt_sigaction, %g1; New signal stack layout */ \
714708c8	89	regp = (struct sig_regs *) (_sip + 1); \
6ea53170	90	regp->pc = ((regp->pc + 4) - 8); \
714708c8 DM	91	} \
	92	while (0)
	93	#else
	94	#define MAKE_THROW_FRAME(_exception) \
	95	do \
	96	{ \
	97	/* Sparc-64 leaves PC pointing at a faulting instruction \
6ea53170 DM	98	always. \
	99	We advance the PC one instruction past the exception causing PC. \
	100	This is done because FDEs are found with "context->ra - 1" in the \
	101	unwinder. \
	102	Also, the dwarf2 unwind machinery is going to add 8 to the \
	103	PC it uses on Sparc. So we adjust the PC here. We do it here \
	104	because we run once for such an exception, however the Sparc specific\
	105	unwind can run multiple times for the same exception and it would \
	106	adjust the PC more than once resulting in a bogus value. */ \
714708c8 DM	107	struct pt_regs { \
	108	unsigned long u_regs[16]; \
	109	unsigned long tstate, tpc, tnpc; \
	110	unsigned int y, fprs; \
	111	} regp = (struct pt_regs ) (_sip + 1); \
6ea53170	112	regp->tpc = ((regp->tpc + 4) - 8); \
714708c8 DM	113	} \
	114	while (0)
	115	#endif
c9bffcd5	116	#else
01936f3a AH	117	#define MAKE_THROW_FRAME(_exception) \
	118	do \
	119	{ \
c9bffcd5	120	(void)_p; \
01936f3a AH	121	} \
01936f3a AH	122	while (0)
c9bffcd5	123	#endif
01936f3a	124
714708c8	125	#if !(defined(__ia64__) \|\| defined(__sparc__))
01936f3a AH	126	#define INIT_SEGV \
	127	do \
	128	{ \
	129	nullp = new java::lang::NullPointerException (); \
	130	struct sigaction act; \
c9bffcd5	131	act.sa_sigaction = _Jv_catch_segv; \
01936f3a	132	sigemptyset (&act.sa_mask); \
c9bffcd5	133	act.sa_flags = SA_SIGINFO; \
d6220b3a	134	syscall (SYS_sigaction, SIGSEGV, &act, NULL); \
01936f3a AH	135	} \
	136	while (0)
	137
	138	#define INIT_FPE \
	139	do \
	140	{ \
	141	arithexception = new java::lang::ArithmeticException \
	142	(JvNewStringLatin1 ("/ by zero")); \
	143	struct sigaction act; \
c9bffcd5	144	act.sa_sigaction = _Jv_catch_fpe; \
01936f3a	145	sigemptyset (&act.sa_mask); \
c9bffcd5	146	act.sa_flags = SA_SIGINFO; \
d6220b3a	147	syscall (SYS_sigaction, SIGFPE, &act, NULL); \
01936f3a AH	148	} \
	149	while (0)
	150
	151	/* We use syscall(SYS_sigaction) in INIT_SEGV and INIT_FPE instead of
	152	* sigaction() because on some systems the pthreads wrappers for
	153	* signal handlers are not compiled with unwind information, so it's
	154	* not possible to unwind through them. This is a problem that will
	155	* go away once all systems have pthreads libraries that are
	156	* compiled with full unwind info. */
	157
714708c8	158	#else /* __ia64__ \|\| __sparc__ */
3cb20545 AH	159
	160	// FIXME: We shouldn't be using libc_sigaction here, since it should
	161	// be glibc private. But using syscall here would mean translating to
	162	// the kernel's struct sigaction and argument sequence, which we
	163	// shouldn't either. The right solution is to call sigaction and to
	164	// make sure that we can unwind correctly through the pthread signal
	165	// wrapper.
	166	extern "C" int __libc_sigaction (int __sig,
	167	__const struct sigaction *__restrict __act,
	168	struct sigaction *__restrict __oact) throw ();
	169
	170	#define INIT_SEGV \
	171	do \
	172	{ \
	173	nullp = new java::lang::NullPointerException (); \
	174	struct sigaction act; \
	175	act.sa_sigaction = _Jv_catch_segv; \
	176	sigemptyset (&act.sa_mask); \
	177	act.sa_flags = SA_SIGINFO; \
	178	__libc_sigaction (SIGSEGV, &act, NULL); \
	179	} \
	180	while (0)
	181
	182	#define INIT_FPE \
	183	do \
	184	{ \
	185	arithexception = new java::lang::ArithmeticException \
	186	(JvNewStringLatin1 ("/ by zero")); \
	187	struct sigaction act; \
	188	act.sa_sigaction = _Jv_catch_fpe; \
	189	sigemptyset (&act.sa_mask); \
	190	act.sa_flags = SA_SIGINFO; \
	191	__libc_sigaction (SIGFPE, &act, NULL); \
	192	} \
	193	while (0)
714708c8	194	#endif /* __ia64__ \|\| __sparc__ */
01936f3a	195	#endif /* JAVA_SIGNAL_H */