tree.h

GCC编译器源代码

/* Front-end tree definitions for GNU compiler.
   Copyright (C) 1989, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC 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.

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

#include "machmode.h"

#ifndef RTX_CODE
struct rtx_def;
#endif

/* Codes of tree nodes */

#define DEFTREECODE(SYM, STRING, TYPE, NARGS)   SYM,

enum tree_code {
#include "tree.def"

  LAST_AND_UNUSED_TREE_CODE	/* A convenient way to get a value for
				   NUM_TREE_CODE.  */
};

#undef DEFTREECODE

/* Number of tree codes.  */
#define NUM_TREE_CODES ((int)LAST_AND_UNUSED_TREE_CODE)

/* Indexed by enum tree_code, contains a character which is
   `<' for a comparison expression, `1', for a unary arithmetic
   expression, `2' for a binary arithmetic expression, `e' for
   other types of expressions, `r' for a reference, `c' for a
   constant, `d' for a decl, `t' for a type, `s' for a statement,
   and `x' for anything else (TREE_LIST, IDENTIFIER, etc).  */

extern char **tree_code_type;
#define TREE_CODE_CLASS(CODE)	(*tree_code_type[(int) (CODE)])

/* Number of argument-words in each kind of tree-node.  */

extern int *tree_code_length;

/* Names of tree components.  */

extern char **tree_code_name;

/* Codes that identify the various built in functions
   so that expand_call can identify them quickly.  */

enum built_in_function
{
  NOT_BUILT_IN,
  BUILT_IN_ALLOCA,
  BUILT_IN_ABS,
  BUILT_IN_FABS,
  BUILT_IN_LABS,
  BUILT_IN_FFS,
  BUILT_IN_DIV,
  BUILT_IN_LDIV,
  BUILT_IN_FFLOOR,
  BUILT_IN_FCEIL,
  BUILT_IN_FMOD,
  BUILT_IN_FREM,
  BUILT_IN_MEMCPY,
  BUILT_IN_MEMCMP,
  BUILT_IN_MEMSET,
  BUILT_IN_STRCPY,
  BUILT_IN_STRCMP,
  BUILT_IN_STRLEN,
  BUILT_IN_FSQRT,
  BUILT_IN_SIN,
  BUILT_IN_COS,
  BUILT_IN_GETEXP,
  BUILT_IN_GETMAN,
  BUILT_IN_SAVEREGS,
  BUILT_IN_CLASSIFY_TYPE,
  BUILT_IN_NEXT_ARG,
  BUILT_IN_ARGS_INFO,
  BUILT_IN_CONSTANT_P,
  BUILT_IN_FRAME_ADDRESS,
  BUILT_IN_RETURN_ADDRESS,
  BUILT_IN_AGGREGATE_INCOMING_ADDRESS,
  BUILT_IN_CALLER_RETURN_ADDRESS,
  BUILT_IN_APPLY_ARGS,
  BUILT_IN_APPLY,
  BUILT_IN_RETURN,
  BUILT_IN_SETJMP,
  BUILT_IN_LONGJMP,

  /* Various hooks for the DWARF 2 __throw routine.  */
  BUILT_IN_FP, BUILT_IN_SP,
  BUILT_IN_UNWIND_INIT,
  BUILT_IN_DWARF_FP_REGNUM,
  BUILT_IN_DWARF_REG_SIZE,
  BUILT_IN_FROB_RETURN_ADDR,
  BUILT_IN_EXTRACT_RETURN_ADDR,
  BUILT_IN_SET_RETURN_ADDR_REG,
  BUILT_IN_EH_STUB,
  BUILT_IN_SET_EH_REGS,

  /* C++ extensions */
  BUILT_IN_NEW,
  BUILT_IN_VEC_NEW,
  BUILT_IN_DELETE,
  BUILT_IN_VEC_DELETE,

  /* Upper bound on non-language-specific builtins. */
  END_BUILTINS
};

/* The definition of tree nodes fills the next several pages.  */

/* A tree node can represent a data type, a variable, an expression
   or a statement.  Each node has a TREE_CODE which says what kind of
   thing it represents.  Some common codes are:
   INTEGER_TYPE -- represents a type of integers.
   ARRAY_TYPE -- represents a type of pointer.
   VAR_DECL -- represents a declared variable.
   INTEGER_CST -- represents a constant integer value.
   PLUS_EXPR -- represents a sum (an expression).

   As for the contents of a tree node: there are some fields
   that all nodes share.  Each TREE_CODE has various special-purpose
   fields as well.  The fields of a node are never accessed directly,
   always through accessor macros.  */

/* This type is used everywhere to refer to a tree node.  */

typedef union tree_node *tree;

/* Every kind of tree node starts with this structure,
   so all nodes have these fields.

   See the accessor macros, defined below, for documentation of the fields.  */

struct tree_common
{
  union tree_node *chain;
  union tree_node *type;
#ifdef ONLY_INT_FIELDS
  unsigned int code : 8;
#else
  enum tree_code code : 8;
#endif

  unsigned side_effects_flag : 1;
  unsigned constant_flag : 1;
  unsigned permanent_flag : 1;
  unsigned addressable_flag : 1;
  unsigned volatile_flag : 1;
  unsigned readonly_flag : 1;
  unsigned unsigned_flag : 1;
  unsigned asm_written_flag: 1;

  unsigned used_flag : 1;
  unsigned raises_flag : 1;
  unsigned static_flag : 1;
  unsigned public_flag : 1;
  unsigned private_flag : 1;
  unsigned protected_flag : 1;

  unsigned lang_flag_0 : 1;
  unsigned lang_flag_1 : 1;
  unsigned lang_flag_2 : 1;
  unsigned lang_flag_3 : 1;
  unsigned lang_flag_4 : 1;
  unsigned lang_flag_5 : 1;
  unsigned lang_flag_6 : 1;
  /* There is room for three more flags.  */
};

/* The following table lists the uses of each of the above flags and
   for which types of nodes they are defined.  Note that expressions
   include decls.

   addressable_flag:

       TREE_ADDRESSABLE in
   	   VAR_DECL, FUNCTION_DECL, CONSTRUCTOR, LABEL_DECL, ..._TYPE
	   IDENTIFIER_NODE

   static_flag:

       TREE_STATIC in
           VAR_DECL, FUNCTION_DECL, CONSTRUCTOR
       TREE_NO_UNUSED_WARNING in
           CONVERT_EXPR, NOP_EXPR, COMPOUND_EXPR
       TREE_VIA_VIRTUAL in
           TREE_LIST or TREE_VEC
       TREE_CONSTANT_OVERFLOW in
           INTEGER_CST, REAL_CST, COMPLEX_CST
       TREE_SYMBOL_REFERENCED in
           IDENTIFIER_NODE

   public_flag:

       TREE_OVERFLOW in
           INTEGER_CST, REAL_CST, COMPLEX_CST
       TREE_PUBLIC in
           VAR_DECL or FUNCTION_DECL
       TREE_VIA_PUBLIC in
           TREE_LIST or TREE_VEC

   private_flag:

       TREE_VIA_PRIVATE in
           TREE_LIST or TREE_VEC
       TREE_PRIVATE in
           ??? unspecified nodes

   protected_flag:

       TREE_VIA_PROTECTED in
           TREE_LIST
       TREE_PROTECTED in
           BLOCK
	   ??? unspecified nodes

   side_effects_flag:

       TREE_SIDE_EFFECTS in
           all expressions

   volatile_flag:

       TREE_THIS_VOLATILE in
           all expressions
       TYPE_VOLATILE in
           ..._TYPE

   readonly_flag:

       TREE_READONLY in
           VAR_DECL, PARM_DECL, FIELD_DECL, ..._REF
       ITERATOR_BOUND_P in
           VAR_DECL if iterator (C)
       TYPE_READONLY in
           ..._TYPE

   constant_flag:

       TREE_CONSTANT in
           all expressions

   permanent_flag: TREE_PERMANENT in all nodes

   unsigned_flag:

       TREE_UNSIGNED in
           INTEGER_TYPE, ENUMERAL_TYPE, FIELD_DECL
       DECL_BUILT_IN_NONANSI in
           FUNCTION_DECL
       TREE_PARMLIST in
           TREE_PARMLIST (C++)
       SAVE_EXPR_NOPLACEHOLDER in
	   SAVE_EXPR

   asm_written_flag:

       TREE_ASM_WRITTEN in
           VAR_DECL, FUNCTION_DECL, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE
	   BLOCK

   used_flag:

       TREE_USED in
           expressions, IDENTIFIER_NODE

   raises_flag:

       TREE_RAISES in
           expressions

							  */
/* Define accessors for the fields that all tree nodes have
   (though some fields are not used for all kinds of nodes).  */

/* The tree-code says what kind of node it is.
   Codes are defined in tree.def.  */
#define TREE_CODE(NODE) ((enum tree_code) (NODE)->common.code)
#define TREE_SET_CODE(NODE, VALUE) ((NODE)->common.code = (int) (VALUE))

/* In all nodes that are expressions, this is the data type of the expression.
   In POINTER_TYPE nodes, this is the type that the pointer points to.
   In ARRAY_TYPE nodes, this is the type of the elements.  */
#define TREE_TYPE(NODE) ((NODE)->common.type)

/* Nodes are chained together for many purposes.
   Types are chained together to record them for being output to the debugger
   (see the function `chain_type').
   Decls in the same scope are chained together to record the contents
   of the scope.
   Statement nodes for successive statements used to be chained together.
   Often lists of things are represented by TREE_LIST nodes that
   are chained together.  */

#define TREE_CHAIN(NODE) ((NODE)->common.chain)

/* Given an expression as a tree, strip any NON_LVALUE_EXPRs and NOP_EXPRs
   that don't change the machine mode.  */

#define STRIP_NOPS(EXP) \
  while ((TREE_CODE (EXP) == NOP_EXPR				\
	  || TREE_CODE (EXP) == CONVERT_EXPR			\
	  || TREE_CODE (EXP) == NON_LVALUE_EXPR)		\
	 && (TYPE_MODE (TREE_TYPE (EXP))			\
	     == TYPE_MODE (TREE_TYPE (TREE_OPERAND (EXP, 0)))))	\
    (EXP) = TREE_OPERAND (EXP, 0);

/* Like STRIP_NOPS, but don't alter the TREE_TYPE either.  */

#define STRIP_TYPE_NOPS(EXP) \
  while ((TREE_CODE (EXP) == NOP_EXPR				\
	  || TREE_CODE (EXP) == CONVERT_EXPR			\
	  || TREE_CODE (EXP) == NON_LVALUE_EXPR)		\
	 && (TREE_TYPE (EXP)					\
	     == TREE_TYPE (TREE_OPERAND (EXP, 0))))		\
    (EXP) = TREE_OPERAND (EXP, 0);

/* Nonzero if TYPE represents an integral type.  Note that we do not
   include COMPLEX types here.  */

#define INTEGRAL_TYPE_P(TYPE)  \
  (TREE_CODE (TYPE) == INTEGER_TYPE || TREE_CODE (TYPE) == ENUMERAL_TYPE  \
   || TREE_CODE (TYPE) == BOOLEAN_TYPE || TREE_CODE (TYPE) == CHAR_TYPE)

/* Nonzero if TYPE represents a floating-point type, including complex
   floating-point types.  */

#define FLOAT_TYPE_P(TYPE)		\
  (TREE_CODE (TYPE) == REAL_TYPE	\
   || (TREE_CODE (TYPE) == COMPLEX_TYPE \
       && TREE_CODE (TREE_TYPE (TYPE)) == REAL_TYPE))

/* Nonzero if TYPE represents an aggregate (multi-component) type. */

#define AGGREGATE_TYPE_P(TYPE) \