2003-06-17 Franz Sirl <Franz.Sirl-kernel@lauterbach.com>

	* include/powerpc-signal.h: New File.
	* configure.in: Use it.
	* configure: Regenerated.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@68088 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 87 insertions, 0 deletions

diff --git a/libjava/include/powerpc-signal.h b/libjava/include/powerpc-signal.h
new file mode 100644
index 00000000000..00a5a6dfb8f
--- /dev/null
+++ b/libjava/include/powerpc-signal.h
@@ -0,0 +1,87 @@
+// powerpc-signal.h - Catch runtime signals and turn them into exceptions
+// on a powerpc based Linux system.
+
+/* Copyright (C) 2003  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
+# undef HANDLE_FPE
+
+# define SIGNAL_HANDLER(_name)						\
+  static void _name (int /* _signal */, struct sigcontext *_sc)
+
+/* PPC 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.  */
+
+# define MAKE_THROW_FRAME(_exception)					\
+do									\
+  {									\
+    _sc->regs->nip += 4;						\
+  }									\
+while (0)
+  
+/* For an explanation why we cannot simply use sigaction to
+   install the handlers, see i386-signal.h.  */
+
+/* We use kernel_old_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.
+   Additionally we want a proper prototype for the handler function
+   with the struct sigcontext pointer passed by the kernel as the 2nd
+   argument, which isn't there in userland headers.
+
+   Note that we explicitly avoid the SA_SIGINFO flag in INIT_SEGV and
+   INIT_FPE below. Using the ucontext pointer passed as 3rd argument
+   of a SA_SIGINFO type handler would need complicated backwards
+   compatibility hacks in MAKE_THROW_FRAME, as the ucontext layout
+   on PPC changed during the 2.5 kernel series.  */
+
+struct kernel_old_sigaction {
+  void (*k_sa_handler) (int, struct sigcontext *);
+  unsigned long k_sa_mask;
+  unsigned long k_sa_flags;
+  void (*k_sa_restorer) (void);
+};
+
+# define INIT_SEGV							\
+do									\
+  {									\
+    nullp = new java::lang::NullPointerException ();			\
+    struct kernel_old_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 kernel_old_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)  
+
+#endif /* JAVA_SIGNAL_H */
+