pa32-linux.h (MD_FALLBACK_FRAME_STATE_FOR): Define.

	* gcc/config/pa/pa32-linux.h (MD_FALLBACK_FRAME_STATE_FOR): Define.
	* libjava/configure.in (SIGNAL_HANDLER): Use pa-signal.h for hppa.
	* libjava/configure: Regenerate.
	* libjava/configure.host: Set can_unwind_signal for hppa*-linux.
	* libjava/pa-signal.h: New file.

From-SVN: r84344

2 files changed, 98 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 04f778f..fb2205c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2004-07-08  Randolph Chung  <tausq@debian.org>
+
+	* pa32-linux.h (MD_FALLBACK_FRAME_STATE_FOR): Define.
+
 2004-07-09  Alexandre Oliva  <aoliva@redhat.com>
 
 	* builtins.c (fold_builtin_strncpy): Make sure len is a constant
diff --git a/gcc/config/pa/pa32-linux.h b/gcc/config/pa/pa32-linux.h
index 4943959..14cc2cf 100644
--- a/gcc/config/pa/pa32-linux.h
+++ b/gcc/config/pa/pa32-linux.h
@@ -35,3 +35,97 @@ Boston, MA 02111-1307, USA.  */
     __attribute__ ((__unused__, section(".ctors"),			\
 		    aligned(sizeof(func_ptr))))				\
     = { (func_ptr) (-1) }
+
+/* Do code reading to identify a signal frame, and set the frame
+   state data appropriately.  See unwind-dw2.c for the structs.  */
+
+#ifdef IN_LIBGCC2
+#include <signal.h>
+#include <sys/ucontext.h>
+
+/* Unfortunately, because of various bugs and changes to the kernel,
+   we have several cases to deal with.
+
+   In 2.4, the signal trampoline is 4 words, and (CONTEXT)->ra should
+   point directly at the beginning of the trampoline and struct rt_sigframe.
+
+   In <= 2.6.5-rc2-pa3, the signal trampoline is 9 words, and 
+   (CONTEXT)->ra points at the 4th word in the trampoline structure.  This 
+   is wrong, it should point at the 5th word.  This is fixed in 2.6.5-rc2-pa4.
+
+   To detect these cases, we first take (CONTEXT)->ra, align it to 64-bytes
+   to get the beginning of the signal frame, and then check offsets 0, 4
+   and 5 to see if we found the beginning of the trampoline.  This will
+   tell us how to locate the sigcontext structure.
+
+   Note that with a 2.4 64-bit kernel, the signal context is not properly
+   passed back to userspace so the unwind will not work correctly.  */
+#define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS)		\
+  do {									\
+    unsigned long sp = (unsigned long)(CONTEXT)->ra & ~63;		\
+    unsigned int *pc = (unsigned int *)sp;				\
+    unsigned long off;							\
+    _Unwind_Ptr new_cfa;						\
+    int i;								\
+    struct sigcontext *sc;						\
+    struct rt_sigframe {						\
+      struct siginfo info;						\
+      struct ucontext uc;						\
+    } *frame;								\
+									\
+    /* rt_sigreturn trampoline: 					\
+       3419000x ldi 0, %r25 or ldi 1, %r25   (x = 0 or 2)  		\
+       3414015a ldi __NR_rt_sigreturn, %r20 				\
+       e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31 			\
+       08000240 nop  */							\
+    									\
+    if (pc[0] == 0x34190000 || pc[0] == 0x34190002)			\
+      off = 4*4;							\
+    else if (pc[4] == 0x34190000 || pc[4] == 0x34190002)		\
+      {									\
+	pc += 4;							\
+	off = 10 * 4;							\
+      }									\
+    else if (pc[5] == 0x34190000 || pc[5] == 0x34190002)		\
+      {									\
+	pc += 5;							\
+	off = 10 * 4;							\
+      }									\
+    else								\
+      break;								\
+    if (pc[1] != 0x3414015a 						\
+	|| pc[2] != 0xe4008200 						\
+	|| pc[3] != 0x08000240)						\
+      break;								\
+									\
+    frame = (struct rt_sigframe *)(sp + off);				\
+    sc = &frame->uc.uc_mcontext;					\
+									\
+    new_cfa = sc->sc_gr[30];						\
+    (FS)->cfa_how = CFA_REG_OFFSET;					\
+    (FS)->cfa_reg = 30;							\
+    (FS)->cfa_offset = new_cfa - (long) (CONTEXT)->cfa;			\
+    for (i = 1; i <= 31; i++)						\
+      {									\
+	(FS)->regs.reg[i].how = REG_SAVED_OFFSET;			\
+	(FS)->regs.reg[i].loc.offset = (long)&sc->sc_gr[i] - new_cfa;	\
+      }									\
+    for (i = 4; i <= 31; i++)						\
+      {									\
+	/* FP regs have left and right halves */			\
+	(FS)->regs.reg[2*i+24].how = REG_SAVED_OFFSET;			\
+	(FS)->regs.reg[2*i+24].loc.offset				\
+	  = (long)&sc->sc_fr[i] - new_cfa;				\
+	(FS)->regs.reg[2*i+24+1].how = REG_SAVED_OFFSET;		\
+	(FS)->regs.reg[2*i+24+1].loc.offset				\
+	  = (long)&sc->sc_fr[i] + 4 - new_cfa;				\
+      }									\
+    (FS)->regs.reg[88].how = REG_SAVED_OFFSET;				\
+    (FS)->regs.reg[88].loc.offset = (long) &sc->sc_sar - new_cfa;	\
+    (FS)->regs.reg[2].how = REG_SAVED_OFFSET;				\
+    (FS)->regs.reg[2].loc.offset = (long) &sc->sc_iaoq[0] - new_cfa;	\
+    (FS)->retaddr_column = 2;						\
+    goto SUCCESS;							\
+  } while (0)
+
+#endif /* IN_LIBGCC2 */