sysv4.h

gcc3.2.1源代码

/* Override definitions in elfos.h/svr4.h to be correct for IA64.  */

/* We want DWARF2 as specified by the IA64 ABI.  */
#undef PREFERRED_DEBUGGING_TYPE
#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG

/* Stabs does not work properly for 64-bit targets.  */
#undef DBX_DEBUGGING_INFO

/* Various pseudo-ops for which the Intel assembler uses non-standard
   definitions.  */

#undef STRING_ASM_OP
#define STRING_ASM_OP "\tstringz\t"

#undef SKIP_ASM_OP
#define SKIP_ASM_OP "\t.skip\t"

#undef COMMON_ASM_OP
#define COMMON_ASM_OP "\t.common\t"

#undef ASCII_DATA_ASM_OP
#define ASCII_DATA_ASM_OP "\tstring\t"

/* ia64-specific options for gas
   ??? ia64 gas doesn't accept standard svr4 assembler options?  */
#undef ASM_SPEC
#define ASM_SPEC "-x %{mconstant-gp} %{mauto-pic} %(asm_extra)"

/* ??? Unfortunately, .lcomm doesn't work, because it puts things in either
   .bss or .sbss, and we can't control the decision of which is used.  When
   I use .lcomm, I get a cryptic "Section group has no member" error from
   the Intel simulator.  So we must explicitly put variables in .bss
   instead.  This matters only if we care about the Intel assembler.  */

/* This is asm_output_aligned_bss from varasm.c without the ASM_GLOBALIZE_LABEL
   call at the beginning.  */

/* This is for final.c, because it is used by ASM_DECLARE_OBJECT_NAME.  */
extern int size_directive_output;

#undef ASM_OUTPUT_ALIGNED_LOCAL
#define ASM_OUTPUT_ALIGNED_DECL_LOCAL(FILE, DECL, NAME, SIZE, ALIGN) \
do {									\
  if ((DECL)								\
      && XSTR (XEXP (DECL_RTL (DECL), 0), 0)[0] == SDATA_NAME_FLAG_CHAR) \
    sbss_section ();							\
  else									\
    bss_section ();							\
  ASM_OUTPUT_ALIGN (FILE, floor_log2 ((ALIGN) / BITS_PER_UNIT));	\
  ASM_DECLARE_OBJECT_NAME (FILE, NAME, DECL);				\
  ASM_OUTPUT_SKIP (FILE, SIZE ? SIZE : 1);				\
} while (0)

/* The # tells the Intel assembler that this is not a register name.
   However, we can't emit the # in a label definition, so we set a variable
   in ASM_OUTPUT_LABEL to control whether we want the postfix here or not.
   We append the # to the label name, but since NAME can be an expression
   we have to scan it for a non-label character and insert the # there.  */

#undef ASM_OUTPUT_LABELREF
#define ASM_OUTPUT_LABELREF(STREAM, NAME)	\
do {						\
  const char *name_ = NAME;			\
  if (*name_ == SDATA_NAME_FLAG_CHAR)		\
    name_++;					\
  if (*name_ == '*')				\
    name_++;					\
  else						\
    fputs (user_label_prefix, STREAM);		\
  fputs (name_, STREAM);			\
  if (!ia64_asm_output_label)			\
    fputc ('#', STREAM);			\
} while (0)

/* Intel assembler requires both flags and type if declaring a non-predefined
   section.  */
#undef INIT_SECTION_ASM_OP
#define INIT_SECTION_ASM_OP	"\t.section\t.init,\"ax\",\"progbits\""
#undef FINI_SECTION_ASM_OP
#define FINI_SECTION_ASM_OP	"\t.section\t.fini,\"ax\",\"progbits\""

/* svr4.h undefines this, so we need to define it here.  */
#define DBX_REGISTER_NUMBER(REGNO) \
  ia64_dbx_register_number(REGNO)

/* Things that svr4.h defines to the wrong type, because it assumes 32 bit
   ints and 32 bit longs.  */

#undef SIZE_TYPE
#define SIZE_TYPE "long unsigned int"

#undef PTRDIFF_TYPE
#define PTRDIFF_TYPE "long int"

#undef WCHAR_TYPE
#define WCHAR_TYPE "int"

#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE 32

/* We redefine this to use the ia64 .proc pseudo-op.  */

#undef ASM_DECLARE_FUNCTION_NAME
#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
do {									\
  fputs ("\t.proc ", FILE);						\
  assemble_name (FILE, NAME);						\
  fputc ('\n', FILE);							\
  ASM_OUTPUT_LABEL (FILE, NAME);					\
} while (0)

/* We redefine this to use the ia64 .endp pseudo-op.  */

#undef ASM_DECLARE_FUNCTION_SIZE
#define ASM_DECLARE_FUNCTION_SIZE(FILE, NAME, DECL) \
do {									\
  fputs ("\t.endp ", FILE);						\
  assemble_name (FILE, NAME);						\
  fputc ('\n', FILE);							\
} while (0)

/* A C expression which outputs to the stdio stream STREAM some appropriate
   text to go at the start of an assembler file.  */

/* ??? Looks like almost every port, except for a few original ones, get this
   wrong.  Must emit #NO_APP as first line of file to turn of special assembler
   preprocessing of files.  */

/* ??? Even worse, it doesn't work, because gas does not accept the tab chars
   that dwarf2out.c emits when #NO_APP.  */

/* ??? Unrelated, but dwarf2out.c emits unnecessary newlines after strings,
   may as well fix at the same time.  */

#undef ASM_FILE_START
#define ASM_FILE_START(STREAM) \
do {									\
  output_file_directive (STREAM, main_input_filename);			\
  emit_safe_across_calls (STREAM);					\
} while (0)

/* A C statement or statements to switch to the appropriate
   section for output of DECL.  DECL is either a `VAR_DECL' node
   or a constant of some sort.  RELOC indicates whether forming
   the initial value of DECL requires link-time relocations.

   Set SECNUM to:
	0	.text
	1	.rodata
	2	.data
	3	.sdata
	4	.bss
	5	.sbss
*/
#define DO_SELECT_SECTION(SECNUM, DECL, RELOC)				\
  do									\
    {									\
      if (TREE_CODE (DECL) == FUNCTION_DECL)				\
	SECNUM = 0;							\
      else if (TREE_CODE (DECL) == STRING_CST)				\
	{								\
	  if (! flag_writable_strings)					\
	    SECNUM = 0x101;						\
	  else								\
	    SECNUM = 2;							\
	}								\
      else if (TREE_CODE (DECL) == VAR_DECL)				\
	{								\
	  if (XSTR (XEXP (DECL_RTL (DECL), 0), 0)[0]			\
	      == SDATA_NAME_FLAG_CHAR)					\
	    SECNUM = 3;							\
	  /* ??? We need the extra RELOC check, because the default	\
	     is to only check RELOC if flag_pic is set, and we don't	\
	     set flag_pic (yet?).  */					\
	  else if (!DECL_READONLY_SECTION (DECL, RELOC) || (RELOC))	\
	    SECNUM = 2;							\
	  else if (flag_merge_constants < 2)				\
	    /* C and C++ don't allow different variables to share	\
	       the same location.  -fmerge-all-constants allows		\
	       even that (at the expense of not conforming).  */	\
	    SECNUM = 1;							\
	  else if (TREE_CODE (DECL_INITIAL (DECL)) == STRING_CST)	\
	    SECNUM = 0x201;						\
	  else								\
	    SECNUM = 0x301;						\
	}								\
      /* This could be a CONSTRUCTOR containing ADDR_EXPR of a VAR_DECL, \
	 in which case we can't put it in a shared library rodata.  */	\
      else if (flag_pic && (RELOC))					\
	SECNUM = 3;							\
      else								\
	SECNUM = 2;							\
    }									\
  while (0)

/* We override svr4.h so that we can support the sdata section.  */

#undef SELECT_SECTION
#define SELECT_SECTION(DECL,RELOC,ALIGN)				\
  do									\
    {									\
      typedef void (*sec_fn) PARAMS ((void));				\
      static sec_fn const sec_functions[6] =				\
      {									\
	text_section,							\
	const_section,							\
	data_section,							\
	sdata_section,							\
	bss_section,							\
	sbss_section							\
      };								\
									\
      int sec;								\
									\
      DO_SELECT_SECTION (sec, DECL, RELOC);				\
									\
      switch (sec)							\
	{								\
	case 0x101:							\
	  mergeable_string_section (DECL, ALIGN, 0);			\
	  break;							\
	case 0x201:							\
	  mergeable_string_section (DECL_INITIAL (DECL),		\
				    ALIGN, 0);				\
	  break;							\
	case 0x301:							\
	  mergeable_constant_section (DECL_MODE (DECL),			\
				      ALIGN, 0);			\
	  break;							\
	default:							\
	  (*sec_functions[sec]) ();					\
	  break;							\
	}								\
    }									\
  while (0)

#undef  UNIQUE_SECTION
#define UNIQUE_SECTION(DECL, RELOC)					\
  do									\
    {									\
      static const char * const prefixes[6][2] =			\
      {									\
	{ ".text.",   ".gnu.linkonce.t." },				\
	{ ".rodata.", ".gnu.linkonce.r." },				\
	{ ".data.",   ".gnu.linkonce.d." },				\
	{ ".sdata.",  ".gnu.linkonce.s." },				\
	{ ".bss.",    ".gnu.linkonce.b." },				\
	{ ".sbss.",   ".gnu.linkonce.sb." }				\
      };								\
									\
      int nlen, plen, sec;						\
      const char *name, *prefix;					\
      char *string;							\
									\
      DO_SELECT_SECTION (sec, DECL, RELOC);				\
									\
      name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL));		\
      STRIP_NAME_ENCODING (name, name);					\
      nlen = strlen (name);						\
									\
      prefix = prefixes[sec & 0xff][DECL_ONE_ONLY(DECL)];		\
      plen = strlen (prefix);						\
									\
      string = alloca (nlen + plen + 1);				\
									\
      memcpy (string, prefix, plen);					\
      memcpy (string + plen, name, nlen + 1);				\
									\
      DECL_SECTION_NAME (DECL) = build_string (nlen + plen, string);	\
    }									\
  while (0)

/* Similarly for constant pool data.  */

extern unsigned int ia64_section_threshold;
#undef SELECT_RTX_SECTION
#define SELECT_RTX_SECTION(MODE, RTX, ALIGN)				\
{									\
  if (GET_MODE_SIZE (MODE) > 0						\
      && GET_MODE_SIZE (MODE) <= ia64_section_threshold)		\
    sdata_section ();							\
  else if (flag_pic && symbolic_operand ((RTX), (MODE)))		\
    data_section ();							\
  else									\
    mergeable_constant_section ((MODE), (ALIGN), 0);			\
}

#undef EXTRA_SECTIONS
#define EXTRA_SECTIONS in_const, in_sdata, in_sbss

#undef EXTRA_SECTION_FUNCTIONS
#define EXTRA_SECTION_FUNCTIONS						\
  CONST_SECTION_FUNCTION						\
  SDATA_SECTION_FUNCTION						\
  SBSS_SECTION_FUNCTION

#define SDATA_SECTION_ASM_OP "\t.sdata"

#define SDATA_SECTION_FUNCTION						\
void									\
sdata_section ()							\
{									\
  if (in_section != in_sdata)						\
    {									\
      fprintf (asm_out_file, "%s\n", SDATA_SECTION_ASM_OP);		\
      in_section = in_sdata;						\
    }									\
}

#define SBSS_SECTION_ASM_OP "\t.sbss"

#define SBSS_SECTION_FUNCTION						\
void									\
sbss_section ()								\
{									\
  if (in_section != in_sbss)						\
    {									\
      fprintf (asm_out_file, "%s\n", SBSS_SECTION_ASM_OP);		\
      in_section = in_sbss;						\
    }									\
}