/* Definitions for SOM assembler support.
   Copyright (C) 1999, 2001, 2002, 2003, 2004, 2005 Free Software Foundation,
   Inc.

This file is part of GCC.

GCC 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, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* So we can conditionalize small amounts of code in pa.c or pa.md.  */
#undef TARGET_SOM
#define TARGET_SOM 1

/* We do not use BINCL stabs in SOM.
   ??? If it does not hurt, we probably should to avoid useless divergence
   from other embedded stabs implementations.  */
#undef DBX_USE_BINCL

#define DBX_LINES_FUNCTION_RELATIVE 1

/* gdb needs a null N_SO at the end of each file for scattered loading.  */

#define DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END

/* Select a format to encode pointers in exception handling data.  CODE
   is 0 for data, 1 for code labels, 2 for function pointers.  GLOBAL is
   true if the symbol may be affected by dynamic relocations.  Because
   the HP assembler does auto alignment, it is necessary to use
   DW_EH_PE_aligned instead of the default DW_EH_PE_absptr.  */

#define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
  (TARGET_GAS ? DW_EH_PE_absptr : DW_EH_PE_aligned)

/* HPUX has a program 'chatr' to list the dependencies of dynamically
   linked executables and shared libraries.  */
#define LDD_SUFFIX "chatr"
/* Look for lines like "dynamic   /usr/lib/X11R5/libX11.sl"
   or "static    /usr/lib/X11R5/libX11.sl". 

   HPUX 10.20 also has lines like "static branch prediction ..."
   so we filter that out explicitly.

   We also try to bound our search for libraries with marker
   lines.  What a pain.  */
#define PARSE_LDD_OUTPUT(PTR)					\
do {								\
  static int in_shlib_list = 0;					\
  while (*PTR == ' ') PTR++;					\
  if (strncmp (PTR, "shared library list:",			\
	       sizeof ("shared library list:") - 1) == 0)	\
    {								\
      PTR = 0;							\
      in_shlib_list = 1;					\
    }								\
  else if (strncmp (PTR, "shared library binding:",		\
		    sizeof ("shared library binding:") - 1) == 0)\
    {								\
      PTR = 0;							\
      in_shlib_list = 0;					\
    }								\
  else if (strncmp (PTR, "static branch prediction disabled",	\
		    sizeof ("static branch prediction disabled") - 1) == 0)\
    {								\
      PTR = 0;							\
      in_shlib_list = 0;					\
    }								\
  else if (in_shlib_list					\
	   &&  strncmp (PTR, "dynamic", sizeof ("dynamic") - 1) == 0) \
    {								\
      PTR += sizeof ("dynamic") - 1;				\
      while (*p == ' ') PTR++;					\
    }								\
  else if (in_shlib_list					\
	   && strncmp (PTR, "static", sizeof ("static") - 1) == 0) \
    {								\
      PTR += sizeof ("static") - 1;				\
      while (*p == ' ') PTR++;					\
    }								\
  else								\
    PTR = 0;							\
} while (0)

/* Output the label for a function definition.  */
#ifndef HP_FP_ARG_DESCRIPTOR_REVERSED
#define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)	\
  do { fprintf (FILE, ",ARGW%d=FR", (ARG0));		\
       fprintf (FILE, ",ARGW%d=FU", (ARG1));} while (0)
#define DFMODE_RETURN_STRING ",RTNVAL=FU"
#define SFMODE_RETURN_STRING ",RTNVAL=FR"
#else
#define ASM_DOUBLE_ARG_DESCRIPTORS(FILE, ARG0, ARG1)	\
  do { fprintf (FILE, ",ARGW%d=FU", (ARG0));		\
       fprintf (FILE, ",ARGW%d=FR", (ARG1));} while (0)
#define DFMODE_RETURN_STRING ",RTNVAL=FR"
#define SFMODE_RETURN_STRING ",RTNVAL=FU"
#endif


#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
    do { tree fntype = TREE_TYPE (TREE_TYPE (DECL));			\
	 tree tree_type = TREE_TYPE (DECL);				\
	 tree parm;							\
	 int i;								\
	 if (TREE_PUBLIC (DECL) || TARGET_GAS)				\
	   { 								\
	     if (TREE_PUBLIC (DECL))					\
	       {							\
		 fputs ("\t.EXPORT ", FILE);				\
		 assemble_name (FILE, NAME);				\
		 fputs (",ENTRY,PRIV_LEV=3", FILE);			\
	       }							\
	     else							\
	       {							\
		 fputs ("\t.PARAM ", FILE);				\
		 assemble_name (FILE, NAME);				\
		 fputs (",PRIV_LEV=3", FILE);				\
	       }							\
	     for (parm = DECL_ARGUMENTS (DECL), i = 0; parm && i < 4;	\
		  parm = TREE_CHAIN (parm))				\
	       {							\
		 if (TYPE_MODE (DECL_ARG_TYPE (parm)) == SFmode		\
		     && ! TARGET_SOFT_FLOAT)				\
		   fprintf (FILE, ",ARGW%d=FR", i++);			\
		 else if (TYPE_MODE (DECL_ARG_TYPE (parm)) == DFmode	\
			  && ! TARGET_SOFT_FLOAT)			\
		   {							\
		     if (i <= 2)					\
		       {						\
			 if (i == 1) i++;				\
			 ASM_DOUBLE_ARG_DESCRIPTORS (FILE, i++, i++);	\
		       }						\
		     else						\
		       break;						\
		   }							\
		 else							\
		   {							\
		     int arg_size =					\
		       FUNCTION_ARG_SIZE (TYPE_MODE (DECL_ARG_TYPE (parm)),\
					  DECL_ARG_TYPE (parm));	\
		     /* Passing structs by invisible reference uses	\
			one general register.  */			\
		     if (arg_size > 2					\
			 || TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))	\
		       arg_size = 1;					\
		     if (arg_size == 2 && i <= 2)			\
		       {						\
			 if (i == 1) i++;				\
			 fprintf (FILE, ",ARGW%d=GR", i++);		\
			 fprintf (FILE, ",ARGW%d=GR", i++);		\
		       }						\
		     else if (arg_size == 1)				\
		       fprintf (FILE, ",ARGW%d=GR", i++);		\
		     else						\
		       i += arg_size;					\
		   }							\
	       }							\
	     /* anonymous args */					\
	     if (TYPE_ARG_TYPES (tree_type) != 0			\
		 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (tree_type)))\
		     != void_type_node))				\
	       {							\
		 for (; i < 4; i++)					\
		   fprintf (FILE, ",ARGW%d=GR", i);			\
	       }							\
	     if (TYPE_MODE (fntype) == DFmode && ! TARGET_SOFT_FLOAT)	\
	       fputs (DFMODE_RETURN_STRING, FILE);			\
	     else if (TYPE_MODE (fntype) == SFmode && ! TARGET_SOFT_FLOAT) \
	       fputs (SFMODE_RETURN_STRING, FILE);			\
	     else if (fntype != void_type_node)				\
	       fputs (",RTNVAL=GR", FILE);				\
	     fputs ("\n", FILE);					\
	   }} while (0)

#define TARGET_ASM_FILE_START pa_som_file_start

/* String to output before text.  */
#define TEXT_SECTION_ASM_OP som_text_section_asm_op ()

/* String to output before writable data.  */
#define DATA_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $DATA$\n"

/* String to output before uninitialized data.  */
#define BSS_SECTION_ASM_OP "\t.SPACE $PRIVATE$\n\t.SUBSPA $BSS$\n"

/* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
   which reference data within the $TEXT$ space (for example constant
   strings in the $LIT$ subspace).

   The assemblers (GAS and HP as) both have problems with handling
   the difference of two symbols which is the other correct way to
   reference constant data during PIC code generation.

   So, there's no way to reference constant data which is in the
   $TEXT$ space during PIC generation.  Instead place all constant
   data into the $PRIVATE$ subspace (this reduces sharing, but it
   works correctly).  */
#define READONLY_DATA_SECTION \
  (flag_pic ? data_section : som_readonly_data_section)

/* We must not have a reference to an external symbol defined in a
   shared library in a readonly section, else the SOM linker will
   complain.

   So, we force exception information into the data section.  */
#define TARGET_ASM_EXCEPTION_SECTION data_section

/* This is how to output a command to make the user-level label
   named NAME defined for reference from other files.  We use
   assemble_name_raw instead of assemble_name since a symbol in
   a .IMPORT directive that isn't otherwise referenced is not
   placed in the symbol table of the assembled object.

   Failure to import a function reference can cause the HP linker
   to segmentation fault!

   Note that the SOM based tools need the symbol imported as a
   CODE symbol, while the ELF based tools require the symbol to
   be imported as an ENTRY symbol.  */

#define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
  pa_hpux_asm_output_external ((FILE), (DECL), (NAME))
#define ASM_OUTPUT_EXTERNAL_REAL(FILE, DECL, NAME) \
  do { fputs ("\t.IMPORT ", FILE);					\
       assemble_name_raw (FILE, NAME);					\
       if (FUNCTION_NAME_P (NAME))					\
	 fputs (",CODE\n", FILE);					\
       else								\
	 fputs (",DATA\n", FILE);					\
     } while (0)

/* The bogus HP assembler requires ALL external references to be
   "imported", even library calls.  They look a bit different, so
   here's this macro.

   Also note not all libcall names are passed to pa_encode_section_info
   (__main for example).  To make sure all libcall names have section
   info recorded in them, we do it here.

   We must also ensure that a libcall that has been previously
   exported is not subsequently imported since the HP assembler may
   change the type from an ENTRY to a CODE symbol.  This would make
   the symbol local.  We are forced to use the identifier node
   associated with the real assembler name for this check as the
   symbol_ref available in ASM_DECLARE_FUNCTION_NAME is not the
   same as the one used here.  As a result, we can't use flags
   in the symbol_ref for this check.  The identifier check assumes
   assemble_external_libcall is called before the symbol is used.  */

#define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, RTL) \
  do { const char *name;						\
       tree id;								\
									\
       if (!function_label_operand (RTL, VOIDmode))			\
	 hppa_encode_label (RTL);					\
									\
       name = targetm.strip_name_encoding (XSTR ((RTL), 0));		\
       id = maybe_get_identifier (name);				\
       if (!id || !TREE_SYMBOL_REFERENCED (id))				\
	 {								\
	   fputs ("\t.IMPORT ", FILE);					\
	   assemble_name_raw (FILE, XSTR ((RTL), 0));		       	\
	   fputs (",CODE\n", FILE);					\
	 }								\
     } while (0)

/* We want __gcc_plt_call to appear in every program built by
   gcc, so we make a reference to it out of __main.
   We use the asm statement to fool the optimizer into not
   removing the dead (but important) initialization of
   REFERENCE.  */

#define DO_GLOBAL_DTORS_BODY			\
do {						\
  extern void __gcc_plt_call (void);		\
  void (*reference)(void) = &__gcc_plt_call;	\
  func_ptr *p;					\
  __asm__ ("" : : "r" (reference));		\
  for (p = __DTOR_LIST__ + 1; *p; )		\
    (*p++) ();					\
} while (0)

/* This macro specifies the biggest alignment supported by the object
   file format of this machine.

   The .align directive in the HP assembler allows alignments up to 4096
   bytes.  However, the maximum alignment of a global common symbol is 8
   bytes for objects smaller than the page size (4096 bytes).  For larger
   objects, the linker provides an alignment of 32 bytes.  Unfortunately,
   this macro doesn't provide a mechanism to test for common symbols.  */
#define MAX_OFILE_ALIGNMENT 32768

/* The SOM linker hardcodes paths into binaries.  As a result, dotdots
   must be removed from library prefixes to prevent binaries from depending
   on the location of the GCC tool directory.  The downside is GCC
   cannot be moved after installation using a symlink.  */
#define ALWAYS_STRIP_DOTDOT 1

/* Aggregates with a single float or double field should be passed and
   returned in the general registers.  */
#define MEMBER_TYPE_FORCES_BLK(FIELD, MODE) (MODE==SFmode || MODE==DFmode)

/* If GAS supports weak, we can support weak when we have working linker
   support for secondary definitions and are generating code for GAS.  */
#ifdef HAVE_GAS_WEAK
#define SUPPORTS_WEAK (TARGET_SOM_SDEF && TARGET_GAS)
#else
#define SUPPORTS_WEAK 0
#endif

/* CVS GAS as of 4/28/04 supports a comdat parameter for the .nsubspa
   directive.  This provides one-only linkage semantics even though we
   don't have weak support.  */
#ifdef HAVE_GAS_NSUBSPA_COMDAT
#define SUPPORTS_SOM_COMDAT (TARGET_GAS)
#else
#define SUPPORTS_SOM_COMDAT 0
#endif

/* We can support one only if we support weak or comdat.  */
#define SUPPORTS_ONE_ONLY (SUPPORTS_WEAK || SUPPORTS_SOM_COMDAT)

/* We use DECL_COMMON for uninitialized one-only variables as we don't
   have linkonce .bss.  We use SOM secondary definitions or comdat for
   initialized variables and functions.  */
#define MAKE_DECL_ONE_ONLY(DECL) \
  do {									\
    if (TREE_CODE (DECL) == VAR_DECL					\
        && (DECL_INITIAL (DECL) == 0					\
            || DECL_INITIAL (DECL) == error_mark_node))			\
      DECL_COMMON (DECL) = 1;						\
    else if (SUPPORTS_WEAK)						\
      DECL_WEAK (DECL) = 1;						\
  } while (0)

/* This is how we tell the assembler that a symbol is weak.  The SOM
   weak implementation uses the secondary definition (sdef) flag.

   The behavior of sdef symbols is similar to ELF weak symbols in that
   multiple definitions can occur without incurring a link error.
   However, they differ in the following ways:
     1) Undefined sdef symbols are not allowed.
     2) The linker searches for undefined sdef symbols and will load an
	archive library member to resolve an undefined sdef symbol.
     3) The exported symbol from a shared library is a primary symbol
        rather than a sdef symbol.  Thus, more care is needed in the
	ordering of libraries.

   It appears that the linker discards extra copies of "weak" functions
   when linking shared libraries, independent of whether or not they
   are in their own section.  In linking final executables, -Wl,-O can
   be used to remove dead procedures.  Thus, support for named sections
   is not needed and in previous testing caused problems with various
   HP tools.  */
#define ASM_WEAKEN_LABEL(FILE,NAME) \
  do { fputs ("\t.weak\t", FILE);				\
       assemble_name (FILE, NAME);				\
       fputc ('\n', FILE);					\
       targetm.asm_out.globalize_label (FILE, NAME);		\
  } while (0)

/* We can't handle weak aliases, and therefore can't support pragma weak.
   Suppress the use of pragma weak in gthr-dce.h and gthr-posix.h.  */
#define GTHREAD_USE_WEAK 0