/* This file contains the definitions and documentation for the
- tree codes used in the GNU C compiler.
- Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000 Free Software Foundation, Inc.
+ tree codes used in GCC.
+ Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004
+ Free Software Foundation, Inc.
-This file is part of GNU CC.
+This file is part of GCC.
-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.
+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.
-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.
+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 GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+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. */
/* The third argument can be:
'<' for codes for comparison expressions.
'1' for codes for unary arithmetic expressions.
'2' for codes for binary arithmetic expressions.
- 's' for codes for expressions with inherent side effects.
+ 's' for codes for "statement" expressions, which have side-effects,
+ but usually no interesting value.
'e' for codes for other kinds of expressions. */
-/* For `r', `e', `<', `1', `2', `s' and `x' nodes,
- the 4th element is the number of argument slots to allocate.
- This determines the size of the tree node object. */
+/* For `r', `e', `<', `1', `2', and `s' nodes, which use struct
+ tree_exp, the 4th element is the number of argument slots to
+ allocate. This determines the size of the tree node object.
+ Other nodes use different structures, and the size is determined
+ by the tree_union member structure; the 4th element should be
+ zero. Languages that define language-specific 'x' or 'c' codes
+ must define the tree_size langhook to say how big they are. */
/* Any erroneous construct is parsed into a node of this type.
This type of node is accepted without complaint in all contexts
Internally it looks like a STRING_CST node.
There is only one IDENTIFIER_NODE ever made for any particular name.
Use `get_identifier' to get it (or create it, the first time). */
-DEFTREECODE (IDENTIFIER_NODE, "identifier_node", 'x', -1)
-
-/* Used to hold information to identify an operator (or combination
- of two operators) considered as a `noun' rather than a `verb'.
- The first operand is encoded in the TREE_TYPE field. */
-DEFTREECODE (OP_IDENTIFIER, "op_identifier", 'x', 2)
+DEFTREECODE (IDENTIFIER_NODE, "identifier_node", 'x', 0)
/* Has the TREE_VALUE and TREE_PURPOSE fields. */
/* These nodes are made into lists by chaining through the
TREE_CHAIN field. The elements of the list live in the
TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
used as well to get the effect of Lisp association lists. */
-DEFTREECODE (TREE_LIST, "tree_list", 'x', 2)
+DEFTREECODE (TREE_LIST, "tree_list", 'x', 0)
/* These nodes contain an array of tree nodes. */
-DEFTREECODE (TREE_VEC, "tree_vec", 'x', 2)
+DEFTREECODE (TREE_VEC, "tree_vec", 'x', 0)
/* A symbol binding block. These are arranged in a tree,
where the BLOCK_SUBBLOCKS field contains a chain of subblocks
could either point to another BLOCK node or it could point to a
FUNCTION_DECL node (e.g. in the case of a block representing the
outermost scope of a particular inlining of a function).
- BLOCK_ABSTRACT is non-zero if the block represents an abstract
+ BLOCK_ABSTRACT is nonzero if the block represents an abstract
instance of a block (i.e. one which is nested within an abstract
instance of an inline function).
- TREE_ASM_WRITTEN is non-zero if the block was actually referenced
+ TREE_ASM_WRITTEN is nonzero if the block was actually referenced
in the generated assembly. */
DEFTREECODE (BLOCK, "block", 'b', 0)
\f
of the real and imaginary parts. */
DEFTREECODE (COMPLEX_TYPE, "complex_type", 't', 0)
+/* Vector types. The TREE_TYPE field is the data type of the vector
+ elements. */
+DEFTREECODE (VECTOR_TYPE, "vector_type", 't', 0)
+
/* C enums. The type node looks just like an INTEGER_TYPE node.
The symbols for the values of the enum type are defined by
CONST_DECL nodes, but the type does not point to them;
TREE_TYPE Type of an array element.
TYPE_DOMAIN Type to index by.
Its range of values specifies the array length.
- TYPE_SEP Expression for units from one elt to the next.
- TYPE_SEP_UNIT Number of bits in a unit for previous.
The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
and holds the type to coerce a value of that array type to in C.
TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
- in languages (such as Chill) that make a distinction. */
+ in languages (such as Chill) that make a distinction. */
/* Array types in C or Pascal */
DEFTREECODE (ARRAY_TYPE, "array_type", 't', 0)
/* Types of sets for Pascal. Special fields are the same as
in an array type. The target type is always a boolean type.
Used for both bitstrings and powersets in Chill;
- TYPE_STRING_FLAG indicates a bitstring. */
+ TYPE_STRING_FLAG indicates a bitstring. */
DEFTREECODE (SET_TYPE, "set_type", 't', 0)
/* Struct in C, or record in Pascal. */
Note: constants of type char in Pascal are INTEGER_CST,
and so are pointer constants such as nil in Pascal or NULL in C.
`(int *) 1' in C also results in an INTEGER_CST. */
-DEFTREECODE (INTEGER_CST, "integer_cst", 'c', 2)
+DEFTREECODE (INTEGER_CST, "integer_cst", 'c', 0)
-/* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */
-DEFTREECODE (REAL_CST, "real_cst", 'c', 3)
+/* Contents are in TREE_REAL_CST field. */
+DEFTREECODE (REAL_CST, "real_cst", 'c', 0)
/* Contents are in TREE_REALPART and TREE_IMAGPART fields,
- whose contents are other constant nodes.
- Also there is TREE_CST_RTL. */
-DEFTREECODE (COMPLEX_CST, "complex_cst", 'c', 3)
-
-/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
- Also there is TREE_CST_RTL. */
-DEFTREECODE (STRING_CST, "string_cst", 'c', 3)
-
-/* Declarations. All references to names are represented as ..._DECL nodes.
- The decls in one binding context are chained through the TREE_CHAIN field.
- Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE.
- (Some decls, most often labels, may have zero as the DECL_NAME).
- DECL_CONTEXT points to the node representing the context in which
- this declaration has its scope. For FIELD_DECLs, this is the
- RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE node that the field
- is a member of. For VAR_DECL, PARM_DECL, FUNCTION_DECL, LABEL_DECL,
- and CONST_DECL nodes, this points to either the FUNCTION_DECL for the
- containing function, the RECORD_TYPE or UNION_TYPE for the containing
- type, or NULL_TREE if the given decl has "file scope".
+ whose contents are other constant nodes. */
+DEFTREECODE (COMPLEX_CST, "complex_cst", 'c', 0)
+
+/* Contents are in TREE_VECTOR_CST_ELTS field. */
+DEFTREECODE (VECTOR_CST, "vector_cst", 'c', 0)
+
+/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields. */
+DEFTREECODE (STRING_CST, "string_cst", 'c', 0)
+
+/* Declarations. All references to names are represented as ..._DECL
+ nodes. The decls in one binding context are chained through the
+ TREE_CHAIN field. Each DECL has a DECL_NAME field which contains
+ an IDENTIFIER_NODE. (Some decls, most often labels, may have zero
+ as the DECL_NAME). DECL_CONTEXT points to the node representing
+ the context in which this declaration has its scope. For
+ FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or
+ QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL,
+ PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this
+ points to either the FUNCTION_DECL for the containing function, the
+ RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or
+ a TRANSLATION_UNIT_DECL if the given decl has "file scope".
DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
..._DECL node of which this decl is an (inlined or template expanded)
instance.
and DECL_MODE fields exist in decl nodes just as in type nodes.
They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
- DECL_OFFSET holds an integer number of bits offset for the location.
- DECL_VOFFSET holds an expression for a variable offset; it is
- to be multiplied by DECL_VOFFSET_UNIT (an integer).
+ DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for
+ the location. DECL_VOFFSET holds an expression for a variable
+ offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer).
These fields are relevant only in FIELD_DECLs and PARM_DECLs.
DECL_INITIAL holds the value to initialize a variable to,
holds a line number. In some cases these can be the location of
a reference, if no definition has been seen.
- DECL_ABSTRACT is non-zero if the decl represents an abstract instance
+ DECL_ABSTRACT is nonzero if the decl represents an abstract instance
of a decl (i.e. one which is nested within an abstract instance of a
inline function. */
/* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
_DECLs, providing a hierarchy of names. */
DEFTREECODE (NAMESPACE_DECL, "namespace_decl", 'd', 0)
+
+/* A translation unit. This is not technically a declaration, since it
+ can't be looked up, but it's close enough. */
+DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl", 'd', 0)
\f
/* References to storage. */
/* Pascal `^` on a file. One operand, an expression for the file. */
DEFTREECODE (BUFFER_REF, "buffer_ref", 'r', 1)
-/* Array indexing in languages other than C.
- Operand 0 is the array; operand 1 is a (single) array index. */
+/* Array indexing.
+ Operand 0 is the array; operand 1 is a (single) array index. */
DEFTREECODE (ARRAY_REF, "array_ref", 'r', 2)
+/* Likewise, except that the result is a range ("slice") of the array. The
+ starting index of the resulting array is taken from operand 1 and the size
+ of the range is taken from the type of the expression. */
+DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", 'r', 2)
+
+/* Vtable indexing. Carries data useful for emitting information
+ for vtable garbage collection.
+ Operand 0: an array_ref (or equivalent expression)
+ Operand 1: the vtable base (must be a var_decl)
+ Operand 2: index into vtable (must be an integer_cst). */
+DEFTREECODE (VTABLE_REF, "vtable_ref", 'r', 3)
+
/* Constructor: return an aggregate value made from specified components.
In C, this is used only for structure and array initializers.
Also used for SET_TYPE in Chill (and potentially Pascal).
- The first "operand" is really a pointer to the RTL,
- for constant constructors only.
- The second operand is a list of component values
- made out of a chain of TREE_LIST nodes.
+ The operand is a list of component values made out of a chain of
+ TREE_LIST nodes.
For ARRAY_TYPE:
The TREE_PURPOSE of each node is the corresponding index.
The TREE_VALUE specifies a value (index) in the set that is true.
If TREE_PURPOSE is non-NULL, it specifies the lower limit of a
range of true values. Elements not listed are false (not in the set). */
-DEFTREECODE (CONSTRUCTOR, "constructor", 'e', 2)
+DEFTREECODE (CONSTRUCTOR, "constructor", 'e', 1)
/* The expression types are mostly straightforward, with the fourth argument
of DEFTREECODE saying how many operands there are.
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. */
+ Operand 0 may be of any type.
+ Operand 1 must have the same type as the entire expression, unless
+ it unconditionally throws an exception, in which case it should
+ have VOID_TYPE. The same constraints apply to operand 2. */
DEFTREECODE (COND_EXPR, "cond_expr", 'e', 3)
/* Declare local variables, including making RTL and allocating space.
/* 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)
+ made out of a chain of TREE_LIST nodes. */
+DEFTREECODE (CALL_EXPR, "call_expr", 'e', 2)
/* 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.
+ Operand 1 is the cleanup expression for the object.
+ Operand 2 is an RTL_EXPR which will eventually represent that value.
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
some field in an object of the type contains a value that is used in
the computation of another field's offset or size and/or the size of
the type. The positions and/or sizes of fields can vary from object
- to object of the same type.
+ to object of the same type or even for one and the same object within
+ its scope.
Record types with discriminants in Ada or schema types in Pascal are
examples of such types. This mechanism is also used to create "fat
For example, if your type FOO is a RECORD_TYPE with a field BAR,
and you need the value of <variable>.BAR to calculate TYPE_SIZE
(FOO), just substitute <variable> above with a PLACEHOLDER_EXPR
- what contains both the expression we wish to
+ whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with
+ the PLACEHOLDER_EXPR as the first operand (which has the correct
+ type). Later, when the size is needed in the program, the back-end
+ will find this PLACEHOLDER_EXPR and generate code to calculate the
+ actual size at run-time. In the following, we describe how this
+ calculation is done.
+
+ When we wish to evaluate a size or offset, we check whether it
+ contains a PLACEHOLDER_EXPR. 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
/* 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)
+
+/* Represents the absolute value of the operand.
+
+ An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The
+ operand of the ABS_EXPR must have the same type. */
DEFTREECODE (ABS_EXPR, "abs_expr", '1', 1)
-DEFTREECODE (FFS_EXPR, "ffs_expr", '1', 1)
/* Shift operations for shift and rotate.
Shift means logical shift if done on an
unsigned type, arithmetic shift if done 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. */
+ shift by; it need not be the same type as the first operand and result.
+ Note that the result is undefined if the second operand is larger
+ than the first operand's type size. */
DEFTREECODE (LSHIFT_EXPR, "lshift_expr", '2', 2)
DEFTREECODE (RSHIFT_EXPR, "rshift_expr", '2', 2)
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", '2', 2)
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). */
+/* 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). The operand may have
+ BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be
+ either zero or one. For example, a TRUTH_NOT_EXPR will never have
+ an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
+ used to compare the VAR_DECL to zero, thereby obtaining a node with
+ value zero or one. */
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 (UNORDERED_EXPR, "unordered_expr", '<', 2)
DEFTREECODE (ORDERED_EXPR, "ordered_expr", '<', 2)
-/* These are equivalent to unordered or ... */
+/* These are equivalent to unordered or ... */
DEFTREECODE (UNLT_EXPR, "unlt_expr", '<', 2)
DEFTREECODE (UNLE_EXPR, "unle_expr", '<', 2)
DEFTREECODE (UNGT_EXPR, "ungt_expr", '<', 2)
/* Value is same as argument, but guaranteed not an lvalue. */
DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", '1', 1)
+/* Represents viewing something of one type as being of a second type.
+ This corresponds to an "Unchecked Conversion" in Ada and roughly to
+ the idiom *(type2 *)&X in C. The only operand is the value to be
+ viewed as being of another type. It is undefined if the type of the
+ input and of the expression have different sizes.
+
+ This code may also be used within the LHS of a MODIFY_EXPR, in which
+ case no actual data motion may occur. TREE_ADDRESSABLE will be set in
+ this case and GCC must abort if it could not do the operation without
+ generating insns. */
+DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_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,
/* 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. Any
- temporaries created during the building of the RTL_EXPR can be
- reused once the RTL_EXPR has been expanded, with the exception of
- the RTL_EXPR_RTL. */
-DEFTREECODE (RTL_EXPR, "rtl_expr", 'e', 2)
+ of insns. The second is the RTL expression for the result. The
+ third operand is the "alternate RTL expression" for the result, if
+ any; if the second argument is the DECL_RTL for a VAR_DECL, but
+ with an invalid memory address replaced by a valid one, then the
+ third operand will be the original DECL_RTL. Any temporaries
+ created during the building of the RTL_EXPR can be reused once the
+ RTL_EXPR has been expanded, with the exception of the
+ RTL_EXPR_RTL. */
+DEFTREECODE (RTL_EXPR, "rtl_expr", 'e', 3)
/* & in C. Value is the address at which the operand's value resides.
Operand may have any mode. Result mode is Pmode. */
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. */
+ of type EPmode. Used only for languages that need static chains. */
DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", 'e', 1)
+/* Operand0 is a function constant; result is part N of a function
+ descriptor of type ptr_mode. */
+DEFTREECODE (FDESC_EXPR, "fdesc_expr", 'e', 2)
+
/* 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)
DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", 'e', 2)
/* Evaluate the first operand.
- The second operand is a a cleanup expression which is evaluated
- before an exit (normal, exception, or jump out) from this expression.
-
- Like a CLEANUP_POINT_EXPR/WITH_CLEANUP_EXPR combination, but those
- always copy the cleanup expression where needed. In contrast,
- TRY_FINALLY_EXPR generates a jump to a cleanup subroutine.
- (At least conceptually; the optimizer could inline the cleanup
- subroutine in the same way it could inline normal subroutines.)
- TRY_FINALLY_EXPR should be used when the cleanup is actual statements
- in the source of the current function (which people might want to
- set breakpoints in). */
+ The second operand is a cleanup expression which is evaluated
+ on any exit (normal, exception, or jump out) from this expression. */
DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", 'e', 2)
/* Used internally for cleanups in the implementation of TRY_FINALLY_EXPR.
Operand 1 is the rtx for a variable in which to store the address
of where the subroutine should return to. */
DEFTREECODE (GOTO_SUBROUTINE_EXPR, "goto_subroutine", '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)
\f
/* These types of expressions have no useful value,
and always have side effects. */
/* Switch expression.
Operand 0 is the expression used to perform the branch,
Operand 1 contains the case values. The way they're organized is
- front-end implementation defined. */
+ front-end implementation defined. */
DEFTREECODE (SWITCH_EXPR, "switch_expr", 'e', 2)
+
+/* The exception object from the runtime. */
+DEFTREECODE (EXC_PTR_EXPR, "exc_ptr_expr", 'e', 0)
+
/*
Local variables:
mode:c
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