12 files changed, 246 insertions, 62 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2c1748f..fbb447a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,80 @@
+Sun May 26 14:14:49 1996  Fred Fish  <fnf@cygnus.com>
+
+	Changes from: David Mosberger-Tang  <davidm@azstarnet.com>
+
+	* NEWS:  Add Alpha Linux as a new native configuration.
+
+	* mdebugread.c (parse_symbol): When we find a malloc() symbol with
+ 	return type VOID, assume no debugging info is available for that
+ 	object file and patch the return value into VOID *.  Otherwise,
+	operations requiring an implicit call to malloc() will fail.
+
+	* infrun.c (wait_for_inferior): The criterion to detect entering a
+ 	sigtramp handler is now: (a) the current pc is inside a sigtramp
+ 	handler, (b) the previous pc is not in a sigtramp handler, and (c)
+ 	the current stack pointer is "inner" than the old one.  Condition
+	(c) is new to avoid mistaking a return from a signal handler into
+ 	sigtramp as a new sigtramp invocation.
+
+	* dcache.c (struct dcache_block): Declare addr as CORE_ADDR.  An
+ 	int may not be big enough to hold an address.
+	(dcache_hit): Ditto.
+	(dcache_peek_byte): Fix indentation.
+
+	* configure.in (alpha-*-linux*): Add target.
+	* configure: Rebuild
+
+	* config/alpha/tm-alpha.h (PROC_DESC_IS_DYN_SIGTRAMP): New macro.
+	(SET_PROC_DESC_IS_DYN_SIGTRAMP): Ditto.
+	(DYNAMIC_SIGTRAMP_OFFSET): Ditto.
+	(SIGCONTEXT_ADDR): Ditto.
+	(FRAME_PAST_SIGTRAMP_FRAME): Ditto.
+
+	* config/alpha/alpha-linux.mh: New file.
+	* config/alpha/alpha-linux.mt: Ditto.
+	* config/alpha/nm-linux.h: Ditto.
+	* config/alpha/tm-alphalinux.h: Ditto.
+	* config/alpha/xm-alphalinux.h: Ditto.
+	* config/alpha/xm-alphaosf.h: Renamed from xm-alpha.h.
+	* config/alpha/alpha-osf1.mh (XM_FILE): Change from xm-alpha.h to
+ 	xm-alphaosf.h.
+	* config/alpha/alpha-osf2.mh: Ditto.
+
+	* blockframe.c (find_pc_partial_function): Pass PC to
+ 	SIGTRAMP_START and SIGTRAMP_END macros for the benefit of systems
+ 	that detect sigtramp code via designated code sequences (as is the
+ 	case for Linux/Alpha, for example).
+	
+	* config/i386/tm-i386bsd.h: Change SIGTRAMP_START and SIGTRAMP_END
+	to ignore new PC argument.
+	* config/m68k/tm-hp300bsd.h: Ditto.
+	* config/vax/tm-vax.h: Ditto.
+
+	* alpha-tdep.c (alpha_linux_sigtramp_offset): New function.
+	(alpha_osf_skip_sigtramp_frame): Ditto.
+	(push_sigtramp_desc): Ditto.
+	(alpha_find_saved_regs): Use SIGCONTEXT_ADDR macro to extract
+ 	sigcontext address from frame.
+	(alpha_saved_pc_after_call): When in sigtramp, use
+ 	alpha_frame_saved_pc() instead of read-register().
+	(after_prologue): When inside a dynamically generated sigtramp
+ 	function, there is no prologue, so return address of first
+ 	instruction.
+	(alpha_in_prologue): Fix typo in comment.
+	(find_proc_desc): Use macro DYNAMIC_SIGTRAMP_OFFSET to determine
+ 	whether we're inside a dynamicaly generated sigtramp function.  If
+ 	so, create and push and appropriate procedure descriptor.
+	(alpha_frame_chain): Use macro FRAME_PAST_SIGTRAMP_FRAME to obtain
+ 	the frame past a sigtramp frame (if the current frame is indeed a
+ 	sigtramp function).
+	(init_extra_frame_info): Don't read next frame register off of
+ 	stack-pointer when inside a dynamiccaly generated sigtramp.
+	(alpha_pop_frame): Also unlink and destroy procedure descriptors
+ 	created for dynamically generated sigtramp functions.
+
+	* alpha-nat.c: When compiling under Linux, include <asm/reg.h> and
+ 	<alpha/ptrace.h> instead of <machine/reg.h>
+
 Thu May 23 15:13:56 1996  Jeffrey A Law  (law@cygnus.com)
 
 	* h8300-tdep.c (IS_PUSH): Refine.
diff --git a/gdb/NEWS b/gdb/NEWS
index 979a878..c6c3841 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -1,6 +1,12 @@
 		What has changed in GDB?
 	     (Organized release by release)
 
+*** Changes since GDB-4.16:
+
+* New native configurations
+
+Alpha Linux					alpha-*-linux*
+
 *** Changes in GDB-4.16:
 
 * New native configurations
diff --git a/gdb/alpha-nat.c b/gdb/alpha-nat.c
index b027116..0102a7b 100644
--- a/gdb/alpha-nat.c
+++ b/gdb/alpha-nat.c
@@ -22,7 +22,12 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 #include "gdbcore.h"
 #include "target.h"
 #include <sys/ptrace.h>
-#include <machine/reg.h>
+#ifdef __linux__
+# include <asm/reg.h>
+# include <alpha/ptrace.h>
+#else
+# include <machine/reg.h>
+#endif
 #include <sys/user.h>
 
 /* Size of elements in jmpbuf */
diff --git a/gdb/alpha-tdep.c b/gdb/alpha-tdep.c
index 7fbf642..d778bf2 100644
--- a/gdb/alpha-tdep.c
+++ b/gdb/alpha-tdep.c
@@ -132,6 +132,110 @@ struct linked_proc_info
 } *linked_proc_desc_table = NULL;
 
 
+/* Under Linux, signal handler invocations can be identified by the
+   designated code sequence that is used to return from a signal
+   handler.  In particular, the return address of a signal handler
+   points to the following sequence (the first instruction is quadword
+   aligned):
+
+	bis $30,$30,$16
+	addq $31,0x67,$0
+	call_pal callsys
+
+   Each instruction has a unique encoding, so we simply attempt to
+   match the instruction the pc is pointing to with any of the above
+   instructions.  If there is a hit, we know the offset to the start
+   of the designated sequence and can then check whether we really are
+   executing in a designated sequence.  If not, -1 is returned,
+   otherwise the offset from the start of the desingated sequence is
+   returned.
+
+   There is a slight chance of false hits: code could jump into the
+   middle of the designated sequence, in which case there is no
+   guarantee that we are in the middle of a sigreturn syscall.  Don't
+   think this will be a problem in praxis, though.
+*/
+long
+alpha_linux_sigtramp_offset (CORE_ADDR pc)
+{
+  unsigned int i[3], w;
+  long off, res;
+
+  if (read_memory_nobpt(pc, (char *) &w, 4) != 0)
+    return -1;
+
+  off = -1;
+  switch (w)
+    {
+    case 0x47de0410: off = 0; break;	/* bis $30,$30,$16 */
+    case 0x43ecf400: off = 4; break;	/* addq $31,0x67,$0 */
+    case 0x00000083: off = 8; break;	/* call_pal callsys */
+    default:	     return -1;
+    }
+  pc -= off;
+  if (pc & 0x7)
+    {
+      /* designated sequence is not quadword aligned */
+      return -1;
+    }
+
+  if (read_memory_nobpt(pc, (char *) i, sizeof(i)) != 0)
+    return -1;
+
+  if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
+    return off;
+
+  return -1;
+}
+
+
+/* Under OSF/1, the __sigtramp routine is frameless and has a frame
+   size of zero, but we are able to backtrace through it.  */
+CORE_ADDR
+alpha_osf_skip_sigtramp_frame (frame, pc)
+     struct frame_info *frame;
+     CORE_ADDR pc;
+{
+  char *name;
+  find_pc_partial_function (pc, &name, (CORE_ADDR *)NULL, (CORE_ADDR *)NULL);
+  if (IN_SIGTRAMP (pc, name))
+    return frame->frame;
+  else
+    return 0;
+}
+
+
+/* Dynamically create a signal-handler caller procedure descriptor for
+   the signal-handler return code starting at address LOW_ADDR.  The
+   descriptor is added to the linked_proc_desc_table.  */
+
+alpha_extra_func_info_t
+push_sigtramp_desc (CORE_ADDR low_addr)
+{
+  struct linked_proc_info *link;
+  alpha_extra_func_info_t proc_desc;
+
+  link = (struct linked_proc_info *)
+    xmalloc (sizeof (struct linked_proc_info));
+  link->next = linked_proc_desc_table;
+  linked_proc_desc_table = link;
+
+  proc_desc = &link->info;
+
+  proc_desc->numargs = 0;
+  PROC_LOW_ADDR (proc_desc)	= low_addr;
+  PROC_HIGH_ADDR (proc_desc)	= low_addr + 3 * 4;
+  PROC_DUMMY_FRAME (proc_desc)	= 0;
+  PROC_FRAME_OFFSET (proc_desc)	= 0x298; /* sizeof(struct sigcontext_struct) */
+  PROC_FRAME_REG (proc_desc)	= SP_REGNUM;
+  PROC_REG_MASK (proc_desc)	= 0xffff;
+  PROC_FREG_MASK (proc_desc)	= 0xffff;
+  PROC_PC_REG (proc_desc)	= 26;
+  PROC_LOCALOFF (proc_desc)	= 0;
+  SET_PROC_DESC_IS_DYN_SIGTRAMP (proc_desc);
+}
+
+
 /* Guaranteed to set frame->saved_regs to some values (it never leaves it
    NULL).  */
 
@@ -161,14 +265,9 @@ alpha_find_saved_regs (frame)
 #endif
   if (frame->signal_handler_caller)
     {
-      CORE_ADDR sigcontext_pointer_addr;
       CORE_ADDR sigcontext_addr;
 
-      if (frame->next)
-	sigcontext_pointer_addr = frame->next->frame;
-      else
-	sigcontext_pointer_addr = frame->frame;
-      sigcontext_addr = read_memory_integer(sigcontext_pointer_addr, 8);
+      sigcontext_addr = SIGCONTEXT_ADDR (frame);
       for (ireg = 0; ireg < 32; ireg++)
 	{
  	  reg_position = sigcontext_addr + SIGFRAME_REGSAVE_OFF + ireg * 8;
@@ -285,7 +384,10 @@ alpha_saved_pc_after_call (frame)
   proc_desc = find_proc_desc (pc, frame->next);
   pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM;
 
-  return read_register (pcreg);
+  if (frame->signal_handler_caller)
+    return alpha_frame_saved_pc (frame);
+  else
+    return read_register (pcreg);
 }
 
 
@@ -471,6 +573,9 @@ after_prologue (pc, proc_desc)
 
   if (proc_desc)
     {
+      if (PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))
+	return PROC_LOW_ADDR (proc_desc);	/* "prologue" is in kernel */
+
       /* If function is frameless, then we need to do it the hard way.  I
 	 strongly suspect that frameless always means prologueless... */
       if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
@@ -493,7 +598,7 @@ after_prologue (pc, proc_desc)
 }
 
 /* Return non-zero if we *might* be in a function prologue.  Return zero if we
-   are definatly *not* in a function prologue.  */
+   are definitively *not* in a function prologue.  */
 
 static int
 alpha_in_prologue (pc, proc_desc)
@@ -599,6 +704,8 @@ find_proc_desc (pc, next_frame)
     }
   else
     {
+      long offset;
+
       /* Is linked_proc_desc_table really necessary?  It only seems to be used
 	 by procedure call dummys.  However, the procedures being called ought
 	 to have their own proc_descs, and even if they don't,
@@ -610,6 +717,12 @@ find_proc_desc (pc, next_frame)
 	      && PROC_HIGH_ADDR(&link->info) > pc)
 	      return &link->info;
 
+      /* If PC is inside a dynamically generated sigtramp handler,
+	 create and push a procedure descriptor for that code: */
+      offset = DYNAMIC_SIGTRAMP_OFFSET (pc);
+      if (offset >= 0)
+	return push_sigtramp_desc (pc - offset);
+
       if (startaddr == 0)
 	startaddr = heuristic_proc_start (pc);
 
@@ -650,17 +763,7 @@ alpha_frame_chain(frame)
 	/* The previous frame from a sigtramp frame might be frameless
 	   and have frame size zero.  */
 	&& !frame->signal_handler_caller)
-      {
-	/* The alpha __sigtramp routine is frameless and has a frame size
-	   of zero, but we are able to backtrace through it. */
-	char *name;
-	find_pc_partial_function (saved_pc, &name,
-				  (CORE_ADDR *)NULL, (CORE_ADDR *)NULL);
-	if (IN_SIGTRAMP (saved_pc, name))
-	  return frame->frame;
-	else
-	  return 0;
-      }
+      return FRAME_PAST_SIGTRAMP_FRAME (frame, saved_pc);
     else
       return read_next_frame_reg(frame, PROC_FRAME_REG(proc_desc))
 	     + PROC_FRAME_OFFSET(proc_desc);
@@ -696,7 +799,8 @@ init_extra_frame_info (frame)
       /* This may not be quite right, if proc has a real frame register.
 	 Get the value of the frame relative sp, procedure might have been
 	 interrupted by a signal at it's very start.  */
-      else if (frame->pc == PROC_LOW_ADDR (proc_desc) && !PROC_DESC_IS_DUMMY (proc_desc))
+      else if (frame->pc == PROC_LOW_ADDR (proc_desc)
+	       && !PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))
 	frame->frame = read_next_frame_reg (frame->next, SP_REGNUM);
       else
 	frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc))
@@ -984,7 +1088,8 @@ alpha_pop_frame()
   write_register (SP_REGNUM, new_sp);
   flush_cached_frames ();
 
-  if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
+  if (proc_desc && (PROC_DESC_IS_DUMMY(proc_desc)
+		    || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)))
     {
       struct linked_proc_info *pi_ptr, *prev_ptr;
 
diff --git a/gdb/config/alpha/xm-alpha.h b/gdb/config/alpha/xm-alpha.h
deleted file mode 100644
index d9f85be..0000000
--- a/gdb/config/alpha/xm-alpha.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Host definitions for GDB running on an alpha under OSF/1
-   Copyright (C) 1992, 1993 Free Software Foundation, Inc.
-
-This file is part of GDB.
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
-
-#if !defined (HOST_BYTE_ORDER)
-#define HOST_BYTE_ORDER LITTLE_ENDIAN
-#endif
-
-/* The alpha has no siginterrupt routine.  */
-#define NO_SIGINTERRUPT
-
-/* HAVE_SGTTY also works, but we have termios, so use it.  */
-
-#define HAVE_TERMIOS
diff --git a/gdb/config/i386/tm-i386bsd.h b/gdb/config/i386/tm-i386bsd.h
index 0b0e3d9..8b8c3a9 100644
--- a/gdb/config/i386/tm-i386bsd.h
+++ b/gdb/config/i386/tm-i386bsd.h
@@ -32,8 +32,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
    the user area. Using constants here allows for cross debugging.
    These are tested for BSDI but should work on 386BSD.  */
 
-#define SIGTRAMP_START	0xfdbfdfc0
-#define SIGTRAMP_END	0xfdbfe000
+#define SIGTRAMP_START(pc)	0xfdbfdfc0
+#define SIGTRAMP_END(pc)	0xfdbfe000
 
 /* Saved Pc.  Get it from sigcontext if within sigtramp.  */
 
diff --git a/gdb/config/m68k/tm-hp300bsd.h b/gdb/config/m68k/tm-hp300bsd.h
index 1c4871d..cdd75dc 100644
--- a/gdb/config/m68k/tm-hp300bsd.h
+++ b/gdb/config/m68k/tm-hp300bsd.h
@@ -52,8 +52,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 /* For 4.4, it is actually right 20 bytes *before* STACK_END_ADDR, so
    include that in the area we test for.  */
 
-#define SIGTRAMP_START (STACK_END_ADDR - 20)
-#define SIGTRAMP_END (STACK_END_ADDR + TARGET_UPAGES * TARGET_NBPG)
+#define SIGTRAMP_START(pc) (STACK_END_ADDR - 20)
+#define SIGTRAMP_END(pc) (STACK_END_ADDR + TARGET_UPAGES * TARGET_NBPG)
 
 /* Address of end of stack space.  */
 
diff --git a/gdb/config/vax/tm-vax.h b/gdb/config/vax/tm-vax.h
index 1e5dacd..7e9774d 100644
--- a/gdb/config/vax/tm-vax.h
+++ b/gdb/config/vax/tm-vax.h
@@ -63,8 +63,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 /* On the VAX, sigtramp is in the u area.  Can't check the exact
    addresses because for cross-debugging we don't have VAX include
    files around.  This should be close enough.  */
-#define SIGTRAMP_START	STACK_END_ADDR
-#define SIGTRAMP_END	0x80000000
+#define SIGTRAMP_START(pc)	STACK_END_ADDR
+#define SIGTRAMP_END(pc)	0x80000000
 
 /* Stack grows downward.  */
 
diff --git a/gdb/configure b/gdb/configure
index cd53d46..1361977 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -3194,6 +3194,7 @@ case "${host}" in
 
 a29k-*-*)		gdb_host=ultra3 ;;
 
+alpha-*-linux*)		gdb_host=alpha-linux ;;
 alpha-*-osf1*)		gdb_host=alpha-osf1 ;;
 alpha-*-osf2*)		gdb_host=alpha-osf2 ;;
 alpha-*-osf[3456789]*)	gdb_host=alpha-osf3 ;;
@@ -3351,6 +3352,7 @@ a29k-*-sym1*)		gdb_target=ultra3 ;;
 a29k-*-udi*)		gdb_target=a29k-udi ;;
 a29k-*-vxworks*)        gdb_target=vx29k ;;
 
+alpha-*-linux*)		gdb_target=alpha-linux ;;
 alpha-*-osf*)		gdb_target=alpha-osf1 ;;
 
 # start-sanitize-arc
diff --git a/gdb/configure.in b/gdb/configure.in
index 5023140..f5f5bdb 100644
--- a/gdb/configure.in
+++ b/gdb/configure.in
@@ -305,6 +305,7 @@ a29k-*-*)		gdb_host=ultra3 ;;
 alpha-*-osf1*)		gdb_host=alpha-osf1 ;;
 alpha-*-osf2*)		gdb_host=alpha-osf2 ;;
 alpha-*-osf[3456789]*)	gdb_host=alpha-osf3 ;;
+alpha-*-linux*)		gdb_host=alpha-linux ;;
 
 arm-*-*)		gdb_host=arm ;;
 
@@ -460,6 +461,7 @@ a29k-*-udi*)		gdb_target=a29k-udi ;;
 a29k-*-vxworks*)        gdb_target=vx29k ;;
 
 alpha-*-osf*)		gdb_target=alpha-osf1 ;;
+alpha-*-linux*)		gdb_target=alpha-linux ;;
 
 # start-sanitize-arc
 arc-*-*)		gdb_target=arc ;;
diff --git a/gdb/dcache.c b/gdb/dcache.c
index f110a0c0..60caa29 100644
--- a/gdb/dcache.c
+++ b/gdb/dcache.c
@@ -111,7 +111,7 @@
 struct dcache_block
 {
   struct dcache_block *p;	/* next in list */
-  unsigned int addr;		/* Address for which data is recorded.  */
+  CORE_ADDR addr;		/* Address for which data is recorded.  */
   char data[LINE_SIZE];		/* bytes at given address */
   unsigned char state[LINE_SIZE]; /* what state the data is in */
 
@@ -155,7 +155,7 @@ static int
 dcache_peek_byte PARAMS ((DCACHE *dcache, CORE_ADDR addr, char *ptr));
 
 static struct dcache_block *
-dcache_hit PARAMS ((DCACHE *dcache, unsigned int addr));
+dcache_hit PARAMS ((DCACHE *dcache, CORE_ADDR addr));
 
 static int dcache_write_line PARAMS ((DCACHE *dcache,struct dcache_block *db));
 
@@ -207,7 +207,7 @@ dcache_flush (dcache)
 static struct dcache_block *
 dcache_hit (dcache, addr)
      DCACHE *dcache;
-     unsigned int addr;
+     CORE_ADDR addr;
 {
   register struct dcache_block *db;
 
@@ -338,7 +338,7 @@ dcache_peek_byte (dcache, addr, ptr)
     else
       db = dcache_alloc (dcache);
       immediate_quit++;
-	    db->addr = MASK (addr);
+      db->addr = MASK (addr);
       while (done < LINE_SIZE) 
 	{
 	  int try =
diff --git a/gdb/mdebugread.c b/gdb/mdebugread.c
index 3fe4f96..89015ba 100644
--- a/gdb/mdebugread.c
+++ b/gdb/mdebugread.c
@@ -835,7 +835,23 @@ parse_symbol (sh, ax, ext_sh, bigend, section_offsets)
       if (sh->sc == scUndefined || sh->sc == scNil)
 	t = mdebug_type_int;
       else
-	t = parse_type (cur_fd, ax, sh->index + 1, 0, bigend, name);
+	{
+	  t = parse_type (cur_fd, ax, sh->index + 1, 0, bigend, name);
+	  if (STREQ(name, "malloc") && t->code == TYPE_CODE_VOID)
+	    {
+	      /* I don't know why, but, at least under Linux/Alpha,
+		 when linking against a malloc without debugging
+		 symbols, its read as a function returning void---this
+		 is bad because it means we cannot call functions with
+		 string arguments interactively; i.e., "call
+		 printf("howdy\n")" would fail with the error message
+		 "program has no memory available".  To avoid this, we
+		 patch up the type and make it void*
+		 instead. (davidm@azstarnet.com)
+		 */
+	      t = t->pointer_type;
+	    }
+	}
       b = top_stack->cur_block;
       if (sh->st == stProc)
 	{