back trace now works when using external memory and frameless functions; all

arguments are passed in args registers until we run out; finding saved regs
now has two offsets not just one doing double duty.
TARGET_READ_SP / TARGET_WRITE_SP are (temporarily?) commented out.

3 files changed, 58 insertions, 22 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2df0bba..5596c8b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,18 @@
+Tue Dec 16 10:29:16 1997  David Taylor  <taylor@texas.cygnus.com>
+
+	* d30v-tdep.c (d30v_frame_chain): don't or in DMEM_START to
+	FP_REGNUM value before return; (prologue_find_regs): two sets
+	of offsets -- frame pointer and stack pointer, not just one that
+	tries to do double duty; (d30v_frame_find_saved_regs): stop once
+	we hit pc (in case we're stopped in the middle of the prologue)
+	and improve handling of frameless prologues; (d30v_push_arguments):
+	*ALL* arguments go on the stack until we run out of args registers,
+	force sp to be 8 byte aligned.
+
+	* config/tm-d30v.h (EXTRACT_STRUCT_VALUE_ADDRESS): fix, it's r2,
+	not r0; (FRAME_CHAIN_VALID): handle use of external memory;
+	(STACK_ALIGN): define.
+
 Mon Dec 15 15:13:57 1997  Andrew Cagney  <cagney@b1.cygnus.com>
 
 	* remote-sim.c (gdbsim_wait): When HAVE_SIGACTION and SA_RESTART
diff --git a/gdb/config/d30v/tm-d30v.h b/gdb/config/d30v/tm-d30v.h
index 931c032..a1a5b58 100644
--- a/gdb/config/d30v/tm-d30v.h
+++ b/gdb/config/d30v/tm-d30v.h
@@ -191,8 +191,7 @@ void d30v_do_registers_info PARAMS ((int regnum, int fpregs));
 /* Extract from an array REGBUF containing the (raw) register state
    the address in which a function should return its structure value,
    as a CORE_ADDR (or an expression that can be used as one).  */
-
-#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
+#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (((CORE_ADDR *)(REGBUF))[2])
 
 
 /* Define other aspects of the stack frame. 
@@ -222,8 +221,13 @@ extern void d30v_init_extra_frame_info PARAMS (( int fromleaf, struct frame_info
 #define FRAME_CHAIN_VALID(chain,frame)	\
       ((chain) != 0 && (frame) != 0 && (frame)->pc > IMEM_START)
 #else
+#if 0
 #define FRAME_CHAIN_VALID(chain,fi)	\
       ((chain) != 0 && (fi) != 0 && (fi)->frame <= STACK_START)
+#else
+#define FRAME_CHAIN_VALID(chain,fi)	\
+      ((chain) != 0 && (fi) != 0 && (fi)->return_pc != 0)
+#endif
 #endif
 #define FRAME_SAVED_PC(FRAME)    ((FRAME)->return_pc)   
 #define FRAME_ARGS_ADDRESS(fi)   (fi)->frame
@@ -311,7 +315,7 @@ extern void d30v_pop_frame PARAMS((void));
 #define REGISTER_SIZE 4
 
 /* Need to handle SP special, as we need to select between spu and spi.  */
-
+#if 0				/* XXX until the simulator is fixed */
 #define TARGET_READ_SP() ((read_register (PSW_REGNUM) & PSW_SM) \
 			  ? read_register (SPU_REGNUM) \
 			  : read_register (SPI_REGNUM))
@@ -319,6 +323,9 @@ extern void d30v_pop_frame PARAMS((void));
 #define TARGET_WRITE_SP(val) ((read_register (PSW_REGNUM) & PSW_SM) \
 			  ? write_register (SPU_REGNUM, (val)) \
 			  : write_register (SPI_REGNUM, (val)))
+#endif
+
+#define STACK_ALIGN(len)	(((len) + 7 ) & ~7)
 
 /* Turn this on to cause remote-sim.c to use sim_set/clear_breakpoint. */
 
diff --git a/gdb/d30v-tdep.c b/gdb/d30v-tdep.c
index 50b3d0d..09cd9e3 100644
--- a/gdb/d30v-tdep.c
+++ b/gdb/d30v-tdep.c
@@ -320,7 +320,7 @@ d30v_frame_chain (frame)
   if (!read_memory_unsigned_integer(fsr.regs[FP_REGNUM],4))
     return (CORE_ADDR)0;
 
-  return read_memory_unsigned_integer(fsr.regs[FP_REGNUM],4)| DMEM_START;
+  return read_memory_unsigned_integer(fsr.regs[FP_REGNUM],4);
 }  
 
 static int next_addr, uses_frame;
@@ -440,16 +440,16 @@ prologue_find_regs (op, fsr, addr)
   if ((op & OP_MASK_ALL_BUT_IMM) == OP_SUB_SP_IMM)
     {
       offset = EXTRACT_IMM6(op);
-      next_addr -= offset;
+      frame_size += -offset;
       return 1;
     }
 
-  /* st  rn, @(sp,0) */
+  /* st  rn, @(sp,0) -- observed */
   if (((op & OP_MASK_ALL_BUT_RA) == OP_STW_SP_R0) ||
       ((op & OP_MASK_ALL_BUT_RA) == OP_STW_SP_IMM0))
     {
       n = EXTRACT_RA(op);
-      fsr->regs[n] = next_addr;
+      fsr->regs[n] = (- frame_size);
       return 1;
     }
 
@@ -458,8 +458,8 @@ prologue_find_regs (op, fsr, addr)
       ((op & OP_MASK_ALL_BUT_RA) == OP_ST2W_SP_IMM0))
     {
       n = EXTRACT_RA(op);
-      fsr->regs[n] = next_addr;
-      fsr->regs[n+1] = next_addr+4;
+      fsr->regs[n] = (- frame_size);
+      fsr->regs[n+1] = (- frame_size) + 4;
       return 1;
     }
 
@@ -490,7 +490,7 @@ d30v_frame_find_saved_regs (fi, fsr)
   pc = get_pc_function_start (fi->pc);
 
   uses_frame = 0;
-  while (1)
+  while (pc < fi->pc)
     {
       opl = (unsigned long)read_memory_integer (pc, 4);
       opr = (unsigned long)read_memory_integer (pc+4, 4);
@@ -554,7 +554,7 @@ d30v_frame_find_saved_regs (fi, fsr)
     }
   
   fi->size = frame_size;
-  if (!fp)
+  if (!fp || !uses_frame)
 #if 0
     fp = read_register(SP_REGNUM) | DMEM_START;
 #else
@@ -571,7 +571,7 @@ d30v_frame_find_saved_regs (fi, fsr)
   else
     fi->return_pc = read_register(LR_REGNUM);
   
-  /* th SP is not normally (ever?) saved, but check anyway */
+  /* the SP is not normally (ever?) saved, but check anyway */
   if (!fsr->regs[SP_REGNUM])
     {
       /* if the FP was saved, that means the current FP is valid, */
@@ -861,27 +861,37 @@ d30v_push_arguments (nargs, args, sp, struct_return, struct_addr)
       struct type *arg_type = check_typedef (VALUE_TYPE (arg));
       len = TYPE_LENGTH (arg_type);
       contents = VALUE_CONTENTS(arg);
-      val = extract_signed_integer (contents, len);
       if (len > 4)
 	{
 	  /* we need multiple registers */
 	  int ndx;
 
-	  for (ndx = 0; ndx < len; ndx += 4, len -= 4)
+	  for (ndx = 0; len > 0; ndx += 8, len -= 8)
 	    {
+	      if (regnum & 1)
+		regnum++;	/* all args > 4 bytes start in even register */
+
 	      if (regnum < 18)
 		{
-		  if (len > 4)
-		    val = extract_signed_integer (&contents[ndx], 4);
-		  else
-		    val = extract_signed_integer (&contents[ndx], len);
+		  val = extract_signed_integer (&contents[ndx], 4);
+		  write_register (regnum++, val);
 
+		  if (len >= 8)
+		    val = extract_signed_integer (&contents[ndx+4], 4);
+		  else
+		    val = extract_signed_integer (&contents[ndx+4], len-4);
 		  write_register (regnum++, val);
 		}
 	      else
 		{
 		  /* no more registers available.  put it on the stack */
-		  sp -= len;
+
+		  /* all args > 4 bytes are padded to a multiple of 8 bytes
+		   and start on an 8 byte boundary */
+		  if (sp & 7)
+		    sp -= (sp & 7); /* align it */
+
+		  sp -= ((len + 7) & ~7); /* allocate space */
 		  write_memory (sp, &contents[ndx], len);
 		  break;
 		}
@@ -891,16 +901,20 @@ d30v_push_arguments (nargs, args, sp, struct_return, struct_addr)
 	{
 	  if (regnum < 18 )
 	    {
+	      val = extract_signed_integer (contents, len);
 	      write_register (regnum++, val);
 	    }
 	  else
 	    {
-	      sp -= len;
-	      store_address (buffer, len, val);
-	      write_memory (sp, buffer, len);
+	      /* all args are padded to a multiple of 4 bytes (at least) */
+	      sp -= ((len + 3) & ~3);
+	      write_memory (sp, contents, len);
 	    }
 	}
     }
+  if (sp & 7)
+    /* stack pointer is not on an 8 byte boundary -- align it */
+    sp -= (sp & 7);
   return sp;
 }