756 lines
35 KiB
Modula-2
756 lines
35 KiB
Modula-2
/* This file contains the definitions and documentation for the
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tree codes used in the GNU C compiler.
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Copyright (C) 1987, 1988, 1993, 1995, 1997 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* The third argument can be:
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'x' for an exceptional code (fits no category).
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't' for a type object code.
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'b' for a lexical block.
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'c' for codes for constants.
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'd' for codes for declarations (also serving as variable refs).
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'r' for codes for references to storage.
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'<' for codes for comparison expressions.
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'1' for codes for unary arithmetic expressions.
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'2' for codes for binary arithmetic expressions.
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's' for codes for expressions with inherent side effects.
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'e' for codes for other kinds of expressions. */
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/* For `r', `e', `<', `1', `2', `s' and `x' nodes,
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the 4th element is the number of argument slots to allocate.
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This determines the size of the tree node object. */
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/* Any erroneous construct is parsed into a node of this type.
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This type of node is accepted without complaint in all contexts
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by later parsing activities, to avoid multiple error messages
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for one error.
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No fields in these nodes are used except the TREE_CODE. */
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DEFTREECODE (ERROR_MARK, "error_mark", 'x', 0)
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/* Used to represent a name (such as, in the DECL_NAME of a decl node).
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Internally it looks like a STRING_CST node.
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There is only one IDENTIFIER_NODE ever made for any particular name.
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Use `get_identifier' to get it (or create it, the first time). */
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DEFTREECODE (IDENTIFIER_NODE, "identifier_node", 'x', -1)
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/* Used to hold information to identify an operator (or combination
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of two operators) considered as a `noun' rather than a `verb'.
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The first operand is encoded in the TREE_TYPE field. */
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DEFTREECODE (OP_IDENTIFIER, "op_identifier", 'x', 2)
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/* Has the TREE_VALUE and TREE_PURPOSE fields. */
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/* These nodes are made into lists by chaining through the
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TREE_CHAIN field. The elements of the list live in the
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TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
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used as well to get the effect of Lisp association lists. */
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DEFTREECODE (TREE_LIST, "tree_list", 'x', 2)
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/* These nodes contain an array of tree nodes. */
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DEFTREECODE (TREE_VEC, "tree_vec", 'x', 2)
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/* A symbol binding block. These are arranged in a tree,
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where the BLOCK_SUBBLOCKS field contains a chain of subblocks
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chained through the BLOCK_CHAIN field.
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BLOCK_SUPERCONTEXT points to the parent block.
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For a block which represents the outermost scope of a function, it
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points to the FUNCTION_DECL node.
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BLOCK_VARS points to a chain of decl nodes.
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BLOCK_TYPE_TAGS points to a chain of types which have their own names.
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BLOCK_CHAIN points to the next BLOCK at the same level.
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BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
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this block is an instance of, or else is NULL to indicate that this
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block is not an instance of anything else. When non-NULL, the value
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could either point to another BLOCK node or it could point to a
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FUNCTION_DECL node (e.g. in the case of a block representing the
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outermost scope of a particular inlining of a function).
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BLOCK_ABSTRACT is non-zero if the block represents an abstract
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instance of a block (i.e. one which is nested within an abstract
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instance of a inline function. */
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DEFTREECODE (BLOCK, "block", 'b', 0)
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/* Each data type is represented by a tree node whose code is one of
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the following: */
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/* Each node that represents a data type has a component TYPE_SIZE
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containing a tree that is an expression for the size in bits.
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The TYPE_MODE contains the machine mode for values of this type.
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The TYPE_POINTER_TO field contains a type for a pointer to this type,
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or zero if no such has been created yet.
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The TYPE_NEXT_VARIANT field is used to chain together types
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that are variants made by type modifiers such as "const" and "volatile".
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The TYPE_MAIN_VARIANT field, in any member of such a chain,
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points to the start of the chain.
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The TYPE_NONCOPIED_PARTS field is a list specifying which parts
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of an object of this type should *not* be copied by assignment.
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The TREE_PURPOSE of each element is the offset of the part
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and the TREE_VALUE is the size in bits of the part.
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The TYPE_NAME field contains info on the name used in the program
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for this type (for GDB symbol table output). It is either a
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TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
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in the case of structs, unions or enums that are known with a tag,
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or zero for types that have no special name.
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The TYPE_CONTEXT for any sort of type which could have a name or
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which could have named members (e.g. tagged types in C/C++) will
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point to the node which represents the scope of the given type, or
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will be NULL_TREE if the type has "file scope". For most types, this
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will point to a BLOCK node or a FUNCTION_DECL node, but it could also
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point to a FUNCTION_TYPE node (for types whose scope is limited to the
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formal parameter list of some function type specification) or it
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could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
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(for C++ "member" types).
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For non-tagged-types, TYPE_CONTEXT need not be set to anything in
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particular, since any type which is of some type category (e.g.
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an array type or a function type) which cannot either have a name
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itself or have named members doesn't really have a "scope" per se.
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The TREE_CHAIN field is used as a forward-references to names for
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ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
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see below. */
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DEFTREECODE (VOID_TYPE, "void_type", 't', 0) /* The void type in C */
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/* Integer types in all languages, including char in C.
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Also used for sub-ranges of other discrete types.
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Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
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and TYPE_PRECISION (number of bits used by this type).
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In the case of a subrange type in Pascal, the TREE_TYPE
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of this will point at the supertype (another INTEGER_TYPE,
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or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
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Otherwise, the TREE_TYPE is zero. */
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DEFTREECODE (INTEGER_TYPE, "integer_type", 't', 0)
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/* C's float and double. Different floating types are distinguished
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by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
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DEFTREECODE (REAL_TYPE, "real_type", 't', 0)
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/* Complex number types. The TREE_TYPE field is the data type
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of the real and imaginary parts. */
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DEFTREECODE (COMPLEX_TYPE, "complex_type", 't', 0)
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/* C enums. The type node looks just like an INTEGER_TYPE node.
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The symbols for the values of the enum type are defined by
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CONST_DECL nodes, but the type does not point to them;
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however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
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is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
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/* A forward reference `enum foo' when no enum named foo is defined yet
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has zero (a null pointer) in its TYPE_SIZE. The tag name is in
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the TYPE_NAME field. If the type is later defined, the normal
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fields are filled in.
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RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
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treated similarly. */
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DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", 't', 0)
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/* Pascal's boolean type (true or false are the only values);
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no special fields needed. */
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DEFTREECODE (BOOLEAN_TYPE, "boolean_type", 't', 0)
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/* CHAR in Pascal; not used in C.
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No special fields needed. */
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DEFTREECODE (CHAR_TYPE, "char_type", 't', 0)
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/* All pointer-to-x types have code POINTER_TYPE.
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The TREE_TYPE points to the node for the type pointed to. */
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DEFTREECODE (POINTER_TYPE, "pointer_type", 't', 0)
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/* An offset is a pointer relative to an object.
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The TREE_TYPE field is the type of the object at the offset.
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The TYPE_OFFSET_BASETYPE points to the node for the type of object
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that the offset is relative to. */
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DEFTREECODE (OFFSET_TYPE, "offset_type", 't', 0)
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/* A reference is like a pointer except that it is coerced
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automatically to the value it points to. Used in C++. */
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DEFTREECODE (REFERENCE_TYPE, "reference_type", 't', 0)
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/* METHOD_TYPE is the type of a function which takes an extra first
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argument for "self", which is not present in the declared argument list.
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The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
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is the type of "self". TYPE_ARG_TYPES is the real argument list, which
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includes the hidden argument for "self". */
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DEFTREECODE (METHOD_TYPE, "method_type", 't', 0)
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/* Used for Pascal; details not determined right now. */
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DEFTREECODE (FILE_TYPE, "file_type", 't', 0)
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/* Types of arrays. Special fields:
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TREE_TYPE Type of an array element.
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TYPE_DOMAIN Type to index by.
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Its range of values specifies the array length.
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TYPE_SEP Expression for units from one elt to the next.
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TYPE_SEP_UNIT Number of bits in a unit for previous.
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The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
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and holds the type to coerce a value of that array type to in C.
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TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
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in languages (such as Chill) that make a distinction. */
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/* Array types in C or Pascal */
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DEFTREECODE (ARRAY_TYPE, "array_type", 't', 0)
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/* Types of sets for Pascal. Special fields are the same as
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in an array type. The target type is always a boolean type.
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Used for both bitstrings and powersets in Chill;
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TYPE_STRING_FLAG indicates a bitstring. */
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DEFTREECODE (SET_TYPE, "set_type", 't', 0)
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/* Struct in C, or record in Pascal. */
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/* Special fields:
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TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct,
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and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
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types and enumerators.
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A few may need to be added for Pascal. */
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/* See the comment above, before ENUMERAL_TYPE, for how
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forward references to struct tags are handled in C. */
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DEFTREECODE (RECORD_TYPE, "record_type", 't', 0)
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/* Union in C. Like a struct, except that the offsets of the fields
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will all be zero. */
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/* See the comment above, before ENUMERAL_TYPE, for how
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forward references to union tags are handled in C. */
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DEFTREECODE (UNION_TYPE, "union_type", 't', 0) /* C union type */
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/* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
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in each FIELD_DECL determine what the union contains. The first
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field whose DECL_QUALIFIER expression is true is deemed to occupy
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the union. */
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DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", 't', 0)
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/* Type of functions. Special fields:
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TREE_TYPE type of value returned.
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TYPE_ARG_TYPES list of types of arguments expected.
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this list is made of TREE_LIST nodes.
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Types of "Procedures" in languages where they are different from functions
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have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
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DEFTREECODE (FUNCTION_TYPE, "function_type", 't', 0)
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/* This is a language-specific kind of type.
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Its meaning is defined by the language front end.
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layout_type does not know how to lay this out,
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so the front-end must do so manually. */
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DEFTREECODE (LANG_TYPE, "lang_type", 't', 0)
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/* Expressions */
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/* First, the constants. */
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/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
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32 bits each, giving us a 64 bit constant capability.
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Note: constants of type char in Pascal are INTEGER_CST,
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and so are pointer constants such as nil in Pascal or NULL in C.
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`(int *) 1' in C also results in an INTEGER_CST. */
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DEFTREECODE (INTEGER_CST, "integer_cst", 'c', 2)
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/* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */
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DEFTREECODE (REAL_CST, "real_cst", 'c', 3)
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/* Contents are in TREE_REALPART and TREE_IMAGPART fields,
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whose contents are other constant nodes.
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Also there is TREE_CST_RTL. */
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DEFTREECODE (COMPLEX_CST, "complex_cst", 'c', 3)
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/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
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Also there is TREE_CST_RTL. */
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DEFTREECODE (STRING_CST, "string_cst", 'c', 3)
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/* Declarations. All references to names are represented as ..._DECL nodes.
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The decls in one binding context are chained through the TREE_CHAIN field.
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Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE.
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(Some decls, most often labels, may have zero as the DECL_NAME).
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DECL_CONTEXT points to the node representing the context in which
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this declaration has its scope. For FIELD_DECLs, this is the
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RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE node that the field
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is a member of. For VAR_DECL, PARM_DECL, FUNCTION_DECL, LABEL_DECL,
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and CONST_DECL nodes, this points to either the FUNCTION_DECL for the
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containing function, the RECORD_TYPE or UNION_TYPE for the containing
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type, or NULL_TREE if the given decl has "file scope".
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DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
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..._DECL node of which this decl is an (inlined or template expanded)
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instance.
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The TREE_TYPE field holds the data type of the object, when relevant.
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LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field
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contents are the type whose name is being declared.
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The DECL_ALIGN, DECL_SIZE,
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and DECL_MODE fields exist in decl nodes just as in type nodes.
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They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
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DECL_OFFSET holds an integer number of bits offset for the location.
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DECL_VOFFSET holds an expression for a variable offset; it is
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to be multiplied by DECL_VOFFSET_UNIT (an integer).
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These fields are relevant only in FIELD_DECLs and PARM_DECLs.
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DECL_INITIAL holds the value to initialize a variable to,
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or the value of a constant. For a function, it holds the body
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(a node of type BLOCK representing the function's binding contour
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and whose body contains the function's statements.) For a LABEL_DECL
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in C, it is a flag, nonzero if the label's definition has been seen.
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PARM_DECLs use a special field:
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DECL_ARG_TYPE is the type in which the argument is actually
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passed, which may be different from its type within the function.
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FUNCTION_DECLs use four special fields:
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DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
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DECL_RESULT holds a RESULT_DECL node for the value of a function,
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or it is 0 for a function that returns no value.
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(C functions returning void have zero here.)
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DECL_RESULT_TYPE holds the type in which the result is actually
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returned. This is usually the same as the type of DECL_RESULT,
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but (1) it may be a wider integer type and
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(2) it remains valid, for the sake of inlining, even after the
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function's compilation is done.
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DECL_FUNCTION_CODE is a code number that is nonzero for
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built-in functions. Its value is an enum built_in_function
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that says which built-in function it is.
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DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
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holds a line number. In some cases these can be the location of
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a reference, if no definition has been seen.
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DECL_ABSTRACT is non-zero if the decl represents an abstract instance
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of a decl (i.e. one which is nested within an abstract instance of a
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inline function. */
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DEFTREECODE (FUNCTION_DECL, "function_decl", 'd', 0)
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DEFTREECODE (LABEL_DECL, "label_decl", 'd', 0)
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DEFTREECODE (CONST_DECL, "const_decl", 'd', 0)
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DEFTREECODE (TYPE_DECL, "type_decl", 'd', 0)
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DEFTREECODE (VAR_DECL, "var_decl", 'd', 0)
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DEFTREECODE (PARM_DECL, "parm_decl", 'd', 0)
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DEFTREECODE (RESULT_DECL, "result_decl", 'd', 0)
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DEFTREECODE (FIELD_DECL, "field_decl", 'd', 0)
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/* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
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_DECLs, providing a hierarchy of names. */
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DEFTREECODE (NAMESPACE_DECL, "namespace_decl", 'd', 0)
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/* References to storage. */
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/* Value is structure or union component.
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Operand 0 is the structure or union (an expression);
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operand 1 is the field (a node of type FIELD_DECL). */
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DEFTREECODE (COMPONENT_REF, "component_ref", 'r', 2)
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/* Reference to a group of bits within an object. Similar to COMPONENT_REF
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except the position is given explicitly rather than via a FIELD_DECL.
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Operand 0 is the structure or union expression;
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operand 1 is a tree giving the number of bits being referenced;
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operand 2 is a tree giving the position of the first referenced bit.
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The field can be either a signed or unsigned field;
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TREE_UNSIGNED says which. */
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DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", 'r', 3)
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/* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
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DEFTREECODE (INDIRECT_REF, "indirect_ref", 'r', 1)
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/* Pascal `^` on a file. One operand, an expression for the file. */
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DEFTREECODE (BUFFER_REF, "buffer_ref", 'r', 1)
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/* Array indexing in languages other than C.
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Operand 0 is the array; operand 1 is a list of indices
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stored as a chain of TREE_LIST nodes. */
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DEFTREECODE (ARRAY_REF, "array_ref", 'r', 2)
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/* Constructor: return an aggregate value made from specified components.
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In C, this is used only for structure and array initializers.
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Also used for SET_TYPE in Chill (and potentially Pascal).
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The first "operand" is really a pointer to the RTL,
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for constant constructors only.
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The second operand is a list of component values
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made out of a chain of TREE_LIST nodes.
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For ARRAY_TYPE:
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The TREE_PURPOSE of each node is the corresponding index.
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If the TREE_PURPOSE is a RANGE_EXPR, it is a short-hand for many nodes,
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one for each index in the range. (If the corresponding TREE_VALUE
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has side-effects, they are evaluated once for each element. Wrap the
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value in a SAVE_EXPR if you want to evaluate side effects only once.)
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For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
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The TREE_PURPOSE of each node is a FIELD_DECL.
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For SET_TYPE:
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The TREE_VALUE specifies a value (index) in the set that is true.
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If TREE_PURPOSE is non-NULL, it specifies the lower limit of a
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range of true values. Elements not listed are false (not in the set). */
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DEFTREECODE (CONSTRUCTOR, "constructor", 'e', 2)
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/* The expression types are mostly straightforward, with the fourth argument
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of DEFTREECODE saying how many operands there are.
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Unless otherwise specified, the operands are expressions and the
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types of all the operands and the expression must all be the same. */
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/* Contains two expressions to compute, one followed by the other.
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the first value is ignored. The second one's value is used. The
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type of the first expression need not agree with the other types. */
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DEFTREECODE (COMPOUND_EXPR, "compound_expr", 'e', 2)
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|
||
/* Assignment expression. Operand 0 is the what to set; 1, the new value. */
|
||
DEFTREECODE (MODIFY_EXPR, "modify_expr", 'e', 2)
|
||
|
||
/* Initialization expression. Operand 0 is the variable to initialize;
|
||
Operand 1 is the initializer. */
|
||
DEFTREECODE (INIT_EXPR, "init_expr", 'e', 2)
|
||
|
||
/* For TARGET_EXPR, operand 0 is the target of an initialization,
|
||
operand 1 is the initializer for the target,
|
||
and operand 2 is the cleanup for this node, if any.
|
||
and operand 3 is the saved initializer after this node has been
|
||
expanded once, this is so we can re-expand the tree later. */
|
||
DEFTREECODE (TARGET_EXPR, "target_expr", 'e', 4)
|
||
|
||
/* Conditional expression ( ... ? ... : ... in C).
|
||
Operand 0 is the condition.
|
||
Operand 1 is the then-value.
|
||
Operand 2 is the else-value.
|
||
Operand 0 may be of any type, but the types of operands 1 and 2
|
||
must be the same and the same as the type of this expression. */
|
||
DEFTREECODE (COND_EXPR, "cond_expr", 'e', 3)
|
||
|
||
/* Declare local variables, including making RTL and allocating space.
|
||
Operand 0 is a chain of VAR_DECL nodes for the variables.
|
||
Operand 1 is the body, the expression to be computed using
|
||
the variables. The value of operand 1 becomes that of the BIND_EXPR.
|
||
Operand 2 is the BLOCK that corresponds to these bindings
|
||
for debugging purposes. If this BIND_EXPR is actually expanded,
|
||
that sets the TREE_USED flag in the BLOCK.
|
||
|
||
The BIND_EXPR is not responsible for informing parsers
|
||
about these variables. If the body is coming from the input file,
|
||
then the code that creates the BIND_EXPR is also responsible for
|
||
informing the parser of the variables.
|
||
|
||
If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
|
||
This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
|
||
If the BIND_EXPR should be output for debugging but will not be expanded,
|
||
set the TREE_USED flag by hand.
|
||
|
||
In order for the BIND_EXPR to be known at all, the code that creates it
|
||
must also install it as a subblock in the tree of BLOCK
|
||
nodes for the function. */
|
||
DEFTREECODE (BIND_EXPR, "bind_expr", 'e', 3)
|
||
|
||
/* Function call. Operand 0 is the function.
|
||
Operand 1 is the argument list, a list of expressions
|
||
made out of a chain of TREE_LIST nodes.
|
||
There is no operand 2. That slot is used for the
|
||
CALL_EXPR_RTL macro (see preexpand_calls). */
|
||
DEFTREECODE (CALL_EXPR, "call_expr", 'e', 3)
|
||
|
||
/* Call a method. Operand 0 is the method, whose type is a METHOD_TYPE.
|
||
Operand 1 is the expression for "self".
|
||
Operand 2 is the list of explicit arguments. */
|
||
DEFTREECODE (METHOD_CALL_EXPR, "method_call_expr", 'e', 4)
|
||
|
||
/* Specify a value to compute along with its corresponding cleanup.
|
||
Operand 0 argument is an expression whose value needs a cleanup.
|
||
Operand 1 is an RTL_EXPR which will eventually represent that value.
|
||
Operand 2 is the cleanup expression for the object.
|
||
The RTL_EXPR is used in this expression, which is how the expression
|
||
manages to act on the proper value.
|
||
The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, if
|
||
it exists, otherwise it is the responsibility of the caller to manually
|
||
call expand_start_target_temps/expand_end_target_temps, as needed.
|
||
|
||
This differs from TRY_CATCH_EXPR in that operand 2 is always
|
||
evaluated when an exception isn't thrown when cleanups are run. */
|
||
DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", 'e', 3)
|
||
|
||
/* Specify a cleanup point.
|
||
Operand 0 is an expression that may have cleanups. If it does, those
|
||
cleanups are executed after the expression is expanded.
|
||
|
||
Note that if the expression is a reference to storage, it is forced out
|
||
of memory before the cleanups are run. This is necessary to handle
|
||
cases where the cleanups modify the storage referenced; in the
|
||
expression 't.i', if 't' is a struct with an integer member 'i' and a
|
||
cleanup which modifies 'i', the value of the expression depends on
|
||
whether the cleanup is run before or after 't.i' is evaluated. When
|
||
expand_expr is run on 't.i', it returns a MEM. This is not good enough;
|
||
the value of 't.i' must be forced out of memory.
|
||
|
||
As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
|
||
BLKmode, because it will not be forced out of memory. */
|
||
DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", 'e', 1)
|
||
|
||
/* The following two codes are used in languages that have types where
|
||
the position and/or sizes of fields vary from object to object of the
|
||
same type, i.e., where some other field in the object contains a value
|
||
that is used in the computation of another field's offset or size.
|
||
|
||
For example, a record type with a discriminant in Ada is such a type.
|
||
This mechanism is also used to create "fat pointers" for unconstrained
|
||
array types in Ada; the fat pointer is a structure one of whose fields is
|
||
a pointer to the actual array type and the other field is a pointer to a
|
||
template, which is a structure containing the bounds of the array. The
|
||
bounds in the type pointed to by the first field in the fat pointer refer
|
||
to the values in the template.
|
||
|
||
These "self-references" are doing using a PLACEHOLDER_EXPR. This is a
|
||
node that will later be replaced with the object being referenced. Its type
|
||
is that of the object and selects which object to use from a chain of
|
||
references (see below).
|
||
|
||
When we wish to evaluate a size or offset, we check it is contains a
|
||
placeholder. If it does, we construct a WITH_RECORD_EXPR that contains
|
||
both the expression we wish to evaluate and an expression within which the
|
||
object may be found. The latter expression is the object itself in
|
||
the simple case of an Ada record with discriminant, but it can be the
|
||
array in the case of an unconstrained array.
|
||
|
||
In the latter case, we need the fat pointer, because the bounds of the
|
||
array can only be accessed from it. However, we rely here on the fact that
|
||
the expression for the array contains the dereference of the fat pointer
|
||
that obtained the array pointer.
|
||
|
||
Accordingly, when looking for the object to substitute in place of
|
||
a PLACEHOLDER_EXPR, we look down the first operand of the expression
|
||
passed as the second operand to WITH_RECORD_EXPR until we find something
|
||
of the desired type or reach a constant. */
|
||
|
||
/* Denotes a record to later be supplied with a WITH_RECORD_EXPR when
|
||
evaluating this expression. The type of this expression is used to
|
||
find the record to replace it. */
|
||
DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", 'x', 0)
|
||
|
||
/* Provide an expression that references a record to be used in place
|
||
of a PLACEHOLDER_EXPR. The record to be used is the record within
|
||
operand 1 that has the same type as the PLACEHOLDER_EXPR in
|
||
operand 0. */
|
||
DEFTREECODE (WITH_RECORD_EXPR, "with_record_expr", 'e', 2)
|
||
|
||
/* Simple arithmetic. */
|
||
DEFTREECODE (PLUS_EXPR, "plus_expr", '2', 2)
|
||
DEFTREECODE (MINUS_EXPR, "minus_expr", '2', 2)
|
||
DEFTREECODE (MULT_EXPR, "mult_expr", '2', 2)
|
||
|
||
/* Division for integer result that rounds the quotient toward zero. */
|
||
DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", '2', 2)
|
||
|
||
/* Division for integer result that rounds the quotient toward infinity. */
|
||
DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", '2', 2)
|
||
|
||
/* Division for integer result that rounds toward minus infinity. */
|
||
DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", '2', 2)
|
||
|
||
/* Division for integer result that rounds toward nearest integer. */
|
||
DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", '2', 2)
|
||
|
||
/* Four kinds of remainder that go with the four kinds of division. */
|
||
DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", '2', 2)
|
||
DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", '2', 2)
|
||
DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", '2', 2)
|
||
DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", '2', 2)
|
||
|
||
/* Division for real result. */
|
||
DEFTREECODE (RDIV_EXPR, "rdiv_expr", '2', 2)
|
||
|
||
/* Division which is not supposed to need rounding.
|
||
Used for pointer subtraction in C. */
|
||
DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", '2', 2)
|
||
|
||
/* Conversion of real to fixed point: four ways to round,
|
||
like the four ways to divide.
|
||
CONVERT_EXPR can also be used to convert a real to an integer,
|
||
and that is what is used in languages that do not have ways of
|
||
specifying which of these is wanted. Maybe these are not needed. */
|
||
DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", '1', 1)
|
||
DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", '1', 1)
|
||
DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", '1', 1)
|
||
DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", '1', 1)
|
||
|
||
/* Conversion of an integer to a real. */
|
||
DEFTREECODE (FLOAT_EXPR, "float_expr", '1', 1)
|
||
|
||
/* Exponentiation. Operands may have any types;
|
||
constraints on value type are not known yet. */
|
||
DEFTREECODE (EXPON_EXPR, "expon_expr", '2', 2)
|
||
|
||
/* Unary negation. */
|
||
DEFTREECODE (NEGATE_EXPR, "negate_expr", '1', 1)
|
||
|
||
DEFTREECODE (MIN_EXPR, "min_expr", '2', 2)
|
||
DEFTREECODE (MAX_EXPR, "max_expr", '2', 2)
|
||
DEFTREECODE (ABS_EXPR, "abs_expr", '1', 1)
|
||
DEFTREECODE (FFS_EXPR, "ffs_expr", '1', 1)
|
||
|
||
/* Shift operations for shift and rotate.
|
||
Shift is supposed to mean logical shift if done on an
|
||
unsigned type, arithmetic shift on a signed type.
|
||
The second operand is the number of bits to
|
||
shift by; it need not be the same type as the first operand and result. */
|
||
DEFTREECODE (LSHIFT_EXPR, "lshift_expr", '2', 2)
|
||
DEFTREECODE (RSHIFT_EXPR, "rshift_expr", '2', 2)
|
||
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", '2', 2)
|
||
DEFTREECODE (RROTATE_EXPR, "rrotate_expr", '2', 2)
|
||
|
||
/* Bitwise operations. Operands have same mode as result. */
|
||
DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", '2', 2)
|
||
DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", '2', 2)
|
||
DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", '2', 2)
|
||
DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", '2', 2)
|
||
DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", '1', 1)
|
||
|
||
/* Combination of boolean values or of integers considered only
|
||
as zero or nonzero. ANDIF and ORIF allow the second operand
|
||
not to be computed if the value of the expression is determined
|
||
from the first operand. AND, OR, and XOR always compute the second
|
||
operand whether its value is needed or not (for side effects). */
|
||
DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", 'e', 2)
|
||
DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", 'e', 2)
|
||
DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", 'e', 2)
|
||
DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", 'e', 2)
|
||
DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", 'e', 2)
|
||
DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", 'e', 1)
|
||
|
||
/* Relational operators.
|
||
`EQ_EXPR' and `NE_EXPR' are allowed for any types.
|
||
The others are allowed only for integer (or pointer or enumeral)
|
||
or real types.
|
||
In all cases the operands will have the same type,
|
||
and the value is always the type used by the language for booleans. */
|
||
DEFTREECODE (LT_EXPR, "lt_expr", '<', 2)
|
||
DEFTREECODE (LE_EXPR, "le_expr", '<', 2)
|
||
DEFTREECODE (GT_EXPR, "gt_expr", '<', 2)
|
||
DEFTREECODE (GE_EXPR, "ge_expr", '<', 2)
|
||
DEFTREECODE (EQ_EXPR, "eq_expr", '<', 2)
|
||
DEFTREECODE (NE_EXPR, "ne_expr", '<', 2)
|
||
|
||
/* Operations for Pascal sets. Not used now. */
|
||
DEFTREECODE (IN_EXPR, "in_expr", '2', 2)
|
||
DEFTREECODE (SET_LE_EXPR, "set_le_expr", '<', 2)
|
||
DEFTREECODE (CARD_EXPR, "card_expr", '1', 1)
|
||
DEFTREECODE (RANGE_EXPR, "range_expr", '2', 2)
|
||
|
||
/* Represents a conversion of type of a value.
|
||
All conversions, including implicit ones, must be
|
||
represented by CONVERT_EXPR or NOP_EXPR nodes. */
|
||
DEFTREECODE (CONVERT_EXPR, "convert_expr", '1', 1)
|
||
|
||
/* Represents a conversion expected to require no code to be generated. */
|
||
DEFTREECODE (NOP_EXPR, "nop_expr", '1', 1)
|
||
|
||
/* Value is same as argument, but guaranteed not an lvalue. */
|
||
DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", '1', 1)
|
||
|
||
/* Represents something we computed once and will use multiple times.
|
||
First operand is that expression. Second is the function decl
|
||
in which the SAVE_EXPR was created. The third operand is the RTL,
|
||
nonzero only after the expression has been computed. */
|
||
DEFTREECODE (SAVE_EXPR, "save_expr", 'e', 3)
|
||
|
||
/* For a UNSAVE_EXPR, operand 0 is the value to unsave. By unsave, we
|
||
mean that all _EXPRs such as TARGET_EXPRs, SAVE_EXPRs,
|
||
CALL_EXPRs and RTL_EXPRs, that are protected
|
||
from being evaluated more than once should be reset so that a new
|
||
expand_expr call of this expr will cause those to be re-evaluated.
|
||
This is useful when we want to reuse a tree in different places,
|
||
but where we must re-expand. */
|
||
DEFTREECODE (UNSAVE_EXPR, "unsave_expr", 'e', 1)
|
||
|
||
/* Represents something whose RTL has already been expanded
|
||
as a sequence which should be emitted when this expression is expanded.
|
||
The first operand is the RTL to emit. It is the first of a chain of insns.
|
||
The second is the RTL expression for the result. */
|
||
DEFTREECODE (RTL_EXPR, "rtl_expr", 'e', 2)
|
||
|
||
/* & in C. Value is the address at which the operand's value resides.
|
||
Operand may have any mode. Result mode is Pmode. */
|
||
DEFTREECODE (ADDR_EXPR, "addr_expr", 'e', 1)
|
||
|
||
/* Non-lvalue reference or pointer to an object. */
|
||
DEFTREECODE (REFERENCE_EXPR, "reference_expr", 'e', 1)
|
||
|
||
/* Operand is a function constant; result is a function variable value
|
||
of typeEPmode. Used only for languages that need static chains. */
|
||
DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", 'e', 1)
|
||
|
||
/* Given two real or integer operands of the same type,
|
||
returns a complex value of the corresponding complex type. */
|
||
DEFTREECODE (COMPLEX_EXPR, "complex_expr", '2', 2)
|
||
|
||
/* Complex conjugate of operand. Used only on complex types. */
|
||
DEFTREECODE (CONJ_EXPR, "conj_expr", '1', 1)
|
||
|
||
/* Used only on an operand of complex type, these return
|
||
a value of the corresponding component type. */
|
||
DEFTREECODE (REALPART_EXPR, "realpart_expr", '1', 1)
|
||
DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", '1', 1)
|
||
|
||
/* Nodes for ++ and -- in C.
|
||
The second arg is how much to increment or decrement by.
|
||
For a pointer, it would be the size of the object pointed to. */
|
||
DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", 'e', 2)
|
||
DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", 'e', 2)
|
||
DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", 'e', 2)
|
||
DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", 'e', 2)
|
||
|
||
/* Evaluate operand 1. If and only if an exception is thrown during
|
||
the evaluation of operand 1, evaluate operand 2.
|
||
|
||
This differs from WITH_CLEANUP_EXPR, in that operand 2 is never
|
||
evaluated unless an exception is throw. */
|
||
DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", 'e', 2)
|
||
|
||
/* Pop the top element off the dynamic handler chain. Used in
|
||
conjunction with setjmp/longjmp based exception handling, see
|
||
except.c for more details. This is meant to be used only by the
|
||
exception handling backend, expand_dhc_cleanup specifically. */
|
||
DEFTREECODE (POPDHC_EXPR, "popdhc_expr", 's', 0)
|
||
|
||
/* Pop the top element off the dynamic cleanup chain. Used in
|
||
conjunction with the exception handling. This is meant to be used
|
||
only by the exception handling backend. */
|
||
DEFTREECODE (POPDCC_EXPR, "popdcc_expr", 's', 0)
|
||
|
||
/* These types of expressions have no useful value,
|
||
and always have side effects. */
|
||
|
||
/* A label definition, encapsulated as a statement.
|
||
Operand 0 is the LABEL_DECL node for the label that appears here.
|
||
The type should be void and the value should be ignored. */
|
||
DEFTREECODE (LABEL_EXPR, "label_expr", 's', 1)
|
||
|
||
/* GOTO. Operand 0 is a LABEL_DECL node.
|
||
The type should be void and the value should be ignored. */
|
||
DEFTREECODE (GOTO_EXPR, "goto_expr", 's', 1)
|
||
|
||
/* RETURN. Evaluates operand 0, then returns from the current function.
|
||
Presumably that operand is an assignment that stores into the
|
||
RESULT_DECL that hold the value to be returned.
|
||
The operand may be null.
|
||
The type should be void and the value should be ignored. */
|
||
DEFTREECODE (RETURN_EXPR, "return_expr", 's', 1)
|
||
|
||
/* Exit the inner most loop conditionally. Operand 0 is the condition.
|
||
The type should be void and the value should be ignored. */
|
||
DEFTREECODE (EXIT_EXPR, "exit_expr", 's', 1)
|
||
|
||
/* A loop. Operand 0 is the body of the loop.
|
||
It must contain an EXIT_EXPR or is an infinite loop.
|
||
The type should be void and the value should be ignored. */
|
||
DEFTREECODE (LOOP_EXPR, "loop_expr", 's', 1)
|
||
|
||
/* Used to represent a tree node, such as IDENTIFIER_NODE or an EXPR
|
||
node, adding several location information: a file name, a line
|
||
number and column number. It is expanded as the node it refers to
|
||
and can be considered a no-op "conversion" with an annotation. */
|
||
DEFTREECODE (EXPR_WITH_FILE_LOCATION, "expr_with_file_location", '1', 2)
|
||
/*
|
||
Local variables:
|
||
mode:c
|
||
End:
|
||
*/
|