2003-10-10 Andrew Cagney <cagney@redhat.com>

	* Makefile.in (ppc-sysv-tdep.o): Add $(gdb_assert_h).
	* rs6000-tdep.c (rs6000_gdbarch_init): When 64 bit SysV ABI, set
	push_dummy_call to ppc64_sysv_abi_push_dummy_call.
	* ppc-sysv-tdep.c: Include "gdb_assert.h".
	(ppc64_sysv_abi_push_dummy_call): New function.
	(ppc64_sysv_abi_broken_push_dummy_call): New function.
	* ppc-tdep.h (ppc64_sysv_abi_push_dummy_call): Declare.
	(ppc64_sysv_abi_broken_push_dummy_call): Declare.

1 files changed, 290 insertions, 1 deletions

diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c
index 82c58daf29e..0b153661e81 100644
--- a/gdb/ppc-sysv-tdep.c
+++ b/gdb/ppc-sysv-tdep.c
@@ -26,7 +26,7 @@
 #include "regcache.h"
 #include "value.h"
 #include "gdb_string.h"
-
+#include "gdb_assert.h"
 #include "ppc-tdep.h"
 
 /* Pass the arguments in either registers, or in the stack. Using the
@@ -317,6 +317,295 @@ ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type)
   return (TYPE_LENGTH (value_type) > 8);
 }
 
+/* Pass the arguments in either registers, or in the stack. Using the
+   ppc 64 bit SysV ABI.
+
+   This implements a dumbed down version of the ABI.  It always writes
+   values to memory, GPR and FPR, even when not necessary.  Doing this
+   greatly simplifies the logic. */
+
+CORE_ADDR
+ppc64_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr,
+				struct regcache *regcache, CORE_ADDR bp_addr,
+				int nargs, struct value **args, CORE_ADDR sp,
+				int struct_return, CORE_ADDR struct_addr)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+  /* By this stage in the proceedings, SP has been decremented by "red
+     zone size" + "struct return size".  Fetch the stack-pointer from
+     before this and use that as the BACK_CHAIN.  */
+  const CORE_ADDR back_chain = read_sp ();
+  /* See for-loop comment below.  */
+  int write_pass;
+  /* Size of the Altivec's vector parameter region, the final value is
+     computed in the for-loop below.  */
+  LONGEST vparam_size = 0;
+  /* Size of the general parameter region, the final value is computed
+     in the for-loop below.  */
+  LONGEST gparam_size = 0;
+  /* Kevin writes ... I don't mind seeing tdep->wordsize used in the
+     calls to align_up(), align_down(), etc.  because this makes it
+     easier to reuse this code (in a copy/paste sense) in the future,
+     but it is a 64-bit ABI and asserting that the wordsize is 8 bytes
+     at some point makes it easier to verify that this function is
+     correct without having to do a non-local analysis to figure out
+     the possible values of tdep->wordsize.  */
+  gdb_assert (tdep->wordsize == 8);
+
+  /* Go through the argument list twice.
+
+     Pass 1: Compute the function call's stack space and register
+     requirements.
+
+     Pass 2: Replay the same computation but this time also write the
+     values out to the target.  */
+
+  for (write_pass = 0; write_pass < 2; write_pass++)
+    {
+      int argno;
+      /* Next available floating point register for float and double
+         arguments.  */
+      int freg = 1;
+      /* Next available general register for non-vector (but possibly
+         float) arguments.  */
+      int greg = 3;
+      /* Next available vector register for vector arguments.  */
+      int vreg = 2;
+      /* The address, at which the next general purpose parameter
+         (integer, struct, float, ...) should be saved.  */
+      CORE_ADDR gparam;
+      /* Address, at which the next Altivec vector parameter should be
+         saved.  */
+      CORE_ADDR vparam;
+
+      if (!write_pass)
+	{
+	  /* During the first pass, GPARAM and VPARAM are more like
+	     offsets (start address zero) than addresses.  That way
+	     the accumulate the total stack space each region
+	     requires.  */
+	  gparam = 0;
+	  vparam = 0;
+	}
+      else
+	{
+	  /* Decrement the stack pointer making space for the Altivec
+	     and general on-stack parameters.  Set vparam and gparam
+	     to their corresponding regions.  */
+	  vparam = align_down (sp - vparam_size, 16);
+	  gparam = align_down (vparam - gparam_size, 16);
+	  /* Add in space for the TOC, link editor double word,
+	     compiler double word, LR save area, CR save area.  */
+	  sp = align_down (gparam - 48, 16);
+	}
+
+      /* If the function is returning a `struct', then there is an
+         extra hidden parameter (which will be passed in r3)
+         containing the address of that struct..  In that case we
+         should advance one word and start from r4 register to copy
+         parameters.  This also consumes one on-stack parameter slot.  */
+      if (struct_return)
+	{
+	  if (write_pass)
+	    regcache_cooked_write_signed (regcache,
+					  tdep->ppc_gp0_regnum + greg,
+					  struct_addr);
+	  greg++;
+	  gparam = align_up (gparam + tdep->wordsize, tdep->wordsize);
+	}
+
+      for (argno = 0; argno < nargs; argno++)
+	{
+	  struct value *arg = args[argno];
+	  struct type *type = check_typedef (VALUE_TYPE (arg));
+	  char *val = VALUE_CONTENTS (arg);
+	  if (TYPE_CODE (type) == TYPE_CODE_FLT && TYPE_LENGTH (type) <= 8)
+	    {
+	      /* Floats and Doubles go in f1 .. f13.  They also
+	         consume a left aligned GREG,, and can end up in
+	         memory.  */
+	      if (write_pass)
+		{
+		  if (ppc_floating_point_unit_p (current_gdbarch)
+		      && freg <= 13)
+		    {
+		      char regval[MAX_REGISTER_SIZE];
+		      struct type *regtype = register_type (gdbarch,
+							    FP0_REGNUM);
+		      convert_typed_floating (val, type, regval, regtype);
+		      regcache_cooked_write (regcache, FP0_REGNUM + freg,
+					     regval);
+		    }
+		  if (greg <= 10)
+		    {
+		      /* The ABI states "Single precision floating
+		         point values are mapped to the first word in
+		         a single doubleword" and "... floating point
+		         values mapped to the first eight doublewords
+		         of the parameter save area are also passed in
+		         general registers").
+
+		         This code interprets that to mean: store it,
+		         left aligned, in the general register.  */
+		      char regval[MAX_REGISTER_SIZE];
+		      memset (regval, 0, sizeof regval);
+		      memcpy (regval, val, TYPE_LENGTH (type));
+		      regcache_cooked_write (regcache,
+					     tdep->ppc_gp0_regnum + greg,
+					     regval);
+		    }
+		  write_memory (gparam, val, TYPE_LENGTH (type));
+		}
+	      /* Always consume parameter stack space.  */
+	      freg++;
+	      greg++;
+	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
+	    }
+	  else if (TYPE_LENGTH (type) == 16 && TYPE_VECTOR (type)
+		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
+		   && tdep->ppc_vr0_regnum >= 0)
+	    {
+	      /* In the Altivec ABI, vectors go in the vector
+	         registers v2 .. v13, or when that runs out, a vector
+	         annex which goes above all the normal parameters.
+	         NOTE: cagney/2003-09-21: This is a guess based on the
+	         PowerOpen Altivec ABI.  */
+	      if (vreg <= 13)
+		{
+		  if (write_pass)
+		    regcache_cooked_write (regcache,
+					   tdep->ppc_vr0_regnum + vreg, val);
+		  vreg++;
+		}
+	      else
+		{
+		  if (write_pass)
+		    write_memory (vparam, val, TYPE_LENGTH (type));
+		  vparam = align_up (vparam + TYPE_LENGTH (type), 16);
+		}
+	    }
+	  else if ((TYPE_CODE (type) == TYPE_CODE_INT
+		    || TYPE_CODE (type) == TYPE_CODE_ENUM)
+		   && TYPE_LENGTH (type) <= 8)
+	    {
+	      /* Scalars get sign[un]extended and go in gpr3 .. gpr10.
+	         They can also end up in memory.  */
+	      if (write_pass)
+		{
+		  /* Sign extend the value, then store it unsigned.  */
+		  ULONGEST word = unpack_long (type, val);
+		  if (greg <= 10)
+		    regcache_cooked_write_unsigned (regcache,
+						    tdep->ppc_gp0_regnum +
+						    greg, word);
+		  write_memory_unsigned_integer (gparam, tdep->wordsize,
+						 word);
+		}
+	      greg++;
+	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
+	    }
+	  else
+	    {
+	      int byte;
+	      for (byte = 0; byte < TYPE_LENGTH (type);
+		   byte += tdep->wordsize)
+		{
+		  if (write_pass && greg <= 10)
+		    {
+		      char regval[MAX_REGISTER_SIZE];
+		      int len = TYPE_LENGTH (type) - byte;
+		      if (len > tdep->wordsize)
+			len = tdep->wordsize;
+		      memset (regval, 0, sizeof regval);
+		      /* WARNING: cagney/2003-09-21: As best I can
+		         tell, the ABI specifies that the value should
+		         be left aligned.  Unfortunately, GCC doesn't
+		         do this - it instead right aligns even sized
+		         values and puts odd sized values on the
+		         stack.  Work around that by putting both a
+		         left and right aligned value into the
+		         register (hopefully no one notices :-^).
+		         Arrrgh!  */
+		      /* Left aligned (8 byte values such as pointers
+		         fill the buffer).  */
+		      memcpy (regval, val + byte, len);
+		      /* Right aligned (but only if even).  */
+		      if (len == 1 || len == 2 || len == 4)
+			memcpy (regval + tdep->wordsize - len,
+				val + byte, len);
+		      regcache_cooked_write (regcache, greg, regval);
+		    }
+		  greg++;
+		}
+	      if (write_pass)
+		/* WARNING: cagney/2003-09-21: Strictly speaking, this
+		   isn't necessary, unfortunately, GCC appears to get
+		   "struct convention" parameter passing wrong putting
+		   odd sized structures in memory instead of in a
+		   register.  Work around this by always writing the
+		   value to memory.  Fortunately, doing this
+		   simplifies the code.  */
+		write_memory (gparam, val, TYPE_LENGTH (type));
+	      /* Always consume parameter stack space.  */
+	      gparam = align_up (gparam + TYPE_LENGTH (type), tdep->wordsize);
+	    }
+	}
+
+      if (!write_pass)
+	{
+	  /* Save the true region sizes ready for the second pass.  */
+	  vparam_size = vparam;
+	  /* Make certain that the general parameter save area is at
+	     least the minimum 8 registers (or doublewords) in size.  */
+	  if (greg < 8)
+	    gparam_size = 8 * tdep->wordsize;
+	  else
+	    gparam_size = gparam;
+	}
+    }
+
+  /* Update %sp.   */
+  regcache_cooked_write_signed (regcache, SP_REGNUM, sp);
+
+  /* Write the backchain (it occupies WORDSIZED bytes).  */
+  write_memory_signed_integer (sp, tdep->wordsize, back_chain);
+
+  /* Point the inferior function call's return address at the dummy's
+     breakpoint.  */
+  regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
+
+  /* Find a value for the TOC register.  Every symbol should have both
+     ".FN" and "FN" in the minimal symbol table.  "FN" points at the
+     FN's descriptor, while ".FN" points at the entry point (which
+     matches FUNC_ADDR).  Need to reverse from FUNC_ADDR back to the
+     FN's descriptor address.  */
+  {
+    /* Find the minimal symbol that corresponds to FUNC_ADDR (should
+       have the name ".FN").  */
+    struct minimal_symbol *dot_fn = lookup_minimal_symbol_by_pc (func_addr);
+    if (dot_fn != NULL && SYMBOL_LINKAGE_NAME (dot_fn)[0] == '.')
+      {
+	/* Now find the corresponding "FN" (dropping ".") minimal
+	   symbol's address.  */
+	struct minimal_symbol *fn =
+	  lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (dot_fn) + 1, NULL,
+				 NULL);
+	if (fn != NULL)
+	  {
+	    /* Got the address of that descriptor.  The TOC is the
+	       second double word.  */
+	    CORE_ADDR toc =
+	      read_memory_unsigned_integer (SYMBOL_VALUE_ADDRESS (fn) +
+					    tdep->wordsize, tdep->wordsize);
+	    regcache_cooked_write_unsigned (regcache,
+					    tdep->ppc_gp0_regnum + 2, toc);
+	  }
+      }
+  }
+
+  return sp;
+}
+
 
 /* The 64 bit ABI retun value convention.