svr4.h

gcc-2.95.3 Linux下最常用的C编译器

/* This is how to allocate empty space in some section.  The .zero
   pseudo-op is used for this on most svr4 assemblers.  */

#define SKIP_ASM_OP	".zero"

#undef ASM_OUTPUT_SKIP
#define ASM_OUTPUT_SKIP(FILE,SIZE) \
  fprintf (FILE, "\t%s\t%u\n", SKIP_ASM_OP, (SIZE))

/* The prefix to add to user-visible assembler symbols.

   For System V Release 4 the convention is *not* to prepend a leading
   underscore onto user-level symbol names.  */

#undef USER_LABEL_PREFIX
#define USER_LABEL_PREFIX ""

/* This is how to output an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.

   For most svr4 systems, the convention is that any symbol which begins
   with a period is not put into the linker symbol table by the assembler.  */

#undef ASM_OUTPUT_INTERNAL_LABEL
#define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM)			\
do {									\
  fprintf (FILE, ".%s%d:\n", PREFIX, NUM);				\
} while (0)

/* This is how to store into the string LABEL
   the symbol_ref name of an internal numbered label where
   PREFIX is the class of label and NUM is the number within the class.
   This is suitable for output with `assemble_name'.

   For most svr4 systems, the convention is that any symbol which begins
   with a period is not put into the linker symbol table by the assembler.  */

#undef ASM_GENERATE_INTERNAL_LABEL
#define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM)			\
do {									\
  sprintf (LABEL, "*.%s%d", PREFIX, (unsigned) (NUM));			\
} while (0)

/* Output the label which precedes a jumptable.  Note that for all svr4
   systems where we actually generate jumptables (which is to say every
   svr4 target except i386, where we use casesi instead) we put the jump-
   tables into the .rodata section and since other stuff could have been
   put into the .rodata section prior to any given jumptable, we have to
   make sure that the location counter for the .rodata section gets pro-
   perly re-aligned prior to the actual beginning of the jump table.  */

#define ALIGN_ASM_OP ".align"

#ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE) \
  ASM_OUTPUT_ALIGN ((FILE), 2);
#endif

#undef ASM_OUTPUT_CASE_LABEL
#define ASM_OUTPUT_CASE_LABEL(FILE,PREFIX,NUM,JUMPTABLE)		\
  do {									\
    ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE)		\
    ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM);			\
  } while (0)

/* The standard SVR4 assembler seems to require that certain builtin
   library routines (e.g. .udiv) be explicitly declared as .globl
   in each assembly file where they are referenced.  */

#define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN)				\
  ASM_GLOBALIZE_LABEL (FILE, XSTR (FUN, 0))

/* This says how to output assembler code to declare an
   uninitialized external linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */

#define COMMON_ASM_OP	".comm"

#undef ASM_OUTPUT_ALIGNED_COMMON
#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)		\
do {									\
  fprintf ((FILE), "\t%s\t", COMMON_ASM_OP);				\
  assemble_name ((FILE), (NAME));					\
  fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT);	\
} while (0)

/* This says how to output assembler code to declare an
   uninitialized internal linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */

#define LOCAL_ASM_OP	".local"

#undef ASM_OUTPUT_ALIGNED_LOCAL
#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)		\
do {									\
  fprintf ((FILE), "\t%s\t", LOCAL_ASM_OP);				\
  assemble_name ((FILE), (NAME));					\
  fprintf ((FILE), "\n");						\
  ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN);			\
} while (0)

/* Biggest alignment supported by the object file format of this
   machine.  Use this macro to limit the alignment which can be
   specified using the `__attribute__ ((aligned (N)))' construct.  If
   not defined, the default value is `BIGGEST_ALIGNMENT'.  */

#define MAX_OFILE_ALIGNMENT (32768*8)

/* This is the pseudo-op used to generate a 32-bit word of data with a
   specific value in some section.  This is the same for all known svr4
   assemblers.  */

#define INT_ASM_OP		".long"

/* This is the pseudo-op used to generate a contiguous sequence of byte
   values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
   AUTOMATICALLY APPENDED.  This is the same for most svr4 assemblers.  */

#undef ASCII_DATA_ASM_OP
#define ASCII_DATA_ASM_OP	".ascii"

/* Support const sections and the ctors and dtors sections for g++.
   Note that there appears to be two different ways to support const
   sections at the moment.  You can either #define the symbol
   READONLY_DATA_SECTION (giving it some code which switches to the
   readonly data section) or else you can #define the symbols
   EXTRA_SECTIONS, EXTRA_SECTION_FUNCTIONS, SELECT_SECTION, and
   SELECT_RTX_SECTION.  We do both here just to be on the safe side.  */

#define USE_CONST_SECTION	1

#define CONST_SECTION_ASM_OP	".section\t.rodata"

/* Define the pseudo-ops used to switch to the .ctors and .dtors sections.

   Note that we want to give these sections the SHF_WRITE attribute
   because these sections will actually contain data (i.e. tables of
   addresses of functions in the current root executable or shared library
   file) and, in the case of a shared library, the relocatable addresses
   will have to be properly resolved/relocated (and then written into) by
   the dynamic linker when it actually attaches the given shared library
   to the executing process.  (Note that on SVR4, you may wish to use the
   `-z text' option to the ELF linker, when building a shared library, as
   an additional check that you are doing everything right.  But if you do
   use the `-z text' option when building a shared library, you will get
   errors unless the .ctors and .dtors sections are marked as writable
   via the SHF_WRITE attribute.)  */

#define CTORS_SECTION_ASM_OP	".section\t.ctors,\"aw\""
#define DTORS_SECTION_ASM_OP	".section\t.dtors,\"aw\""

/* On svr4, we *do* have support for the .init and .fini sections, and we
   can put stuff in there to be executed before and after `main'.  We let
   crtstuff.c and other files know this by defining the following symbols.
   The definitions say how to change sections to the .init and .fini
   sections.  This is the same for all known svr4 assemblers.  */

#define INIT_SECTION_ASM_OP	".section\t.init"
#define FINI_SECTION_ASM_OP	".section\t.fini"

/* A default list of other sections which we might be "in" at any given
   time.  For targets that use additional sections (e.g. .tdesc) you
   should override this definition in the target-specific file which
   includes this file.  */

#undef EXTRA_SECTIONS
#define EXTRA_SECTIONS in_const, in_ctors, in_dtors

/* A default list of extra section function definitions.  For targets
   that use additional sections (e.g. .tdesc) you should override this
   definition in the target-specific file which includes this file.  */

#undef EXTRA_SECTION_FUNCTIONS
#define EXTRA_SECTION_FUNCTIONS						\
  CONST_SECTION_FUNCTION						\
  CTORS_SECTION_FUNCTION						\
  DTORS_SECTION_FUNCTION

#define READONLY_DATA_SECTION() const_section ()

extern void text_section ();

#define CONST_SECTION_FUNCTION						\
void									\
const_section ()							\
{									\
  if (!USE_CONST_SECTION)						\
    text_section();							\
  else if (in_section != in_const)					\
    {									\
      fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP);		\
      in_section = in_const;						\
    }									\
}

#define CTORS_SECTION_FUNCTION						\
void									\
ctors_section ()							\
{									\
  if (in_section != in_ctors)						\
    {									\
      fprintf (asm_out_file, "%s\n", CTORS_SECTION_ASM_OP);		\
      in_section = in_ctors;						\
    }									\
}

#define DTORS_SECTION_FUNCTION						\
void									\
dtors_section ()							\
{									\
  if (in_section != in_dtors)						\
    {									\
      fprintf (asm_out_file, "%s\n", DTORS_SECTION_ASM_OP);		\
      in_section = in_dtors;						\
    }									\
}

/* Switch into a generic section.
 
   We make the section read-only and executable for a function decl,
   read-only for a const data decl, and writable for a non-const data decl.
 
   If the section has already been defined, we must not
   emit the attributes here. The SVR4 assembler does not
   recognize section redefinitions.
   If DECL is NULL, no attributes are emitted.  */

#define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC)		\
do {									\
  static struct section_info						\
    {									\
      struct section_info *next;				        \
      char *name;						        \
      enum sect_enum {SECT_RW, SECT_RO, SECT_EXEC} type;		\
    } *sections;							\
  struct section_info *s;						\
  char *mode;								\
  enum sect_enum type;							\
									\
  for (s = sections; s; s = s->next)					\
    if (!strcmp (NAME, s->name))					\
      break;								\
									\
  if (DECL && TREE_CODE (DECL) == FUNCTION_DECL)			\
    type = SECT_EXEC, mode = "ax";					\
  else if (DECL && DECL_READONLY_SECTION (DECL, RELOC))			\
    type = SECT_RO, mode = "a";						\
  else									\
    type = SECT_RW, mode = "aw";					\
									\
  if (s == 0)								\
    {									\
      s = (struct section_info *) xmalloc (sizeof (struct section_info));  \
      s->name = xmalloc ((strlen (NAME) + 1) * sizeof (*NAME));		\
      strcpy (s->name, NAME);						\
      s->type = type;							\
      s->next = sections;						\
      sections = s;							\
      fprintf (FILE, ".section\t%s,\"%s\",@progbits\n", NAME, mode);	\
    }									\
  else									\
    {									\
      if (DECL && s->type != type)					\
	error_with_decl (DECL, "%s causes a section type conflict");	\
									\
      fprintf (FILE, ".section\t%s\n", NAME);				\
    }									\
} while (0)

#define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
#define UNIQUE_SECTION_P(DECL) (DECL_ONE_ONLY (DECL))
#define UNIQUE_SECTION(DECL,RELOC)				\
do {								\
  int len;							\
  char *name, *string, *prefix;					\
								\
  name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL));	\
								\
  if (! DECL_ONE_ONLY (DECL))					\
    {								\
      prefix = ".";                                             \
      if (TREE_CODE (DECL) == FUNCTION_DECL)			\
	prefix = ".text.";					\
      else if (DECL_READONLY_SECTION (DECL, RELOC))		\
	prefix = ".rodata.";					\
      else							\
	prefix = ".data.";					\
    }								\
  else if (TREE_CODE (DECL) == FUNCTION_DECL)			\
    prefix = ".gnu.linkonce.t.";				\
  else if (DECL_READONLY_SECTION (DECL, RELOC))			\
    prefix = ".gnu.linkonce.r.";				\
  else								\
    prefix = ".gnu.linkonce.d.";				\
								\
  len = strlen (name) + strlen (prefix);			\
  string = alloca (len + 1);					\
  sprintf (string, "%s%s", prefix, name);			\
								\
  DECL_SECTION_NAME (DECL) = build_string (len, string);	\
} while (0)
/* A C statement (sans semicolon) to output an element in the table of
   global constructors.  */
#define ASM_OUTPUT_CONSTRUCTOR(FILE,NAME)				\
  do {									\
    ctors_section ();							\
    fprintf (FILE, "\t%s\t ", INT_ASM_OP);				\