/* This file contains the definitions and documentation for the
tree codes used in the GNU C compiler.
- Copyright (C) 1987, 1988, 1993, 1995, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001
+ Free Software Foundation, Inc.
This file is part of GNU CC.
outermost scope of a particular inlining of a function).
BLOCK_ABSTRACT is non-zero if the block represents an abstract
instance of a block (i.e. one which is nested within an abstract
- instance of a inline function. */
+ instance of an inline function).
+ TREE_ASM_WRITTEN is non-zero if the block was actually referenced
+ in the generated assembly. */
DEFTREECODE (BLOCK, "block", 'b', 0)
\f
/* Each data type is represented by a tree node whose code is one of
points to the start of the chain.
The TYPE_NONCOPIED_PARTS field is a list specifying which parts
of an object of this type should *not* be copied by assignment.
- The TREE_PURPOSE of each element is the offset of the part
- and the TREE_VALUE is the size in bits of the part.
+ The TREE_VALUE of each is a FIELD_DECL that should not be
+ copied. The TREE_PURPOSE is an initial value for that field when
+ an object of this type is initialized via an INIT_EXPR. It may
+ be NULL if no special value is required. Even the things in this
+ list are copied if the right-hand side of an assignment is known
+ to be a complete object (rather than being, perhaps, a subobject
+ of some other object.) The determination of what constitutes a
+ complete object is done by fixed_type_p.
The TYPE_NAME field contains info on the name used in the program
for this type (for GDB symbol table output). It is either a
TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
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;
DECL_RESULT holds a RESULT_DECL node for the value of a function,
or it is 0 for a function that returns no value.
(C functions returning void have zero here.)
- DECL_RESULT_TYPE holds the type in which the result is actually
- returned. This is usually the same as the type of DECL_RESULT,
- but (1) it may be a wider integer type and
- (2) it remains valid, for the sake of inlining, even after the
- function's compilation is done.
+ The TREE_TYPE field is the type in which the result is actually
+ returned. This is usually the same as the return type of the
+ FUNCTION_DECL, but it may be a wider integer type because of
+ promotion.
DECL_FUNCTION_CODE is a code number that is nonzero for
built-in functions. Its value is an enum built_in_function
that says which built-in function it is.
/* 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 list of indices
- stored as a chain of TREE_LIST nodes. */
+/* 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)
+
/* 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).
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)
+ made out of a chain of TREE_LIST nodes. */
+DEFTREECODE (CALL_EXPR, "call_expr", 'e', 2)
/* Call a method. Operand 0 is the method, whose type is a METHOD_TYPE.
Operand 1 is the expression for "self".
/* 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
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.
+ 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.
+
+ Record types with discriminants in Ada or schema types in Pascal are
+ examples of such types. 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.
+
+ When you wish to construct such a type you need "self-references"
+ that allow you to reference the object having this type from the
+ TYPE node, i.e. without having a variable instantiating this type.
+
+ Such a "self-references" is done 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). No other slots are used in the
+ PLACEHOLDER_EXPR.
+
+ 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
+ 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. */
+ 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
/* 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 is supposed to mean logical shift if done on an
- unsigned type, arithmetic shift on a signed type.
+ 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_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
+ a 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 (EQ_EXPR, "eq_expr", '<', 2)
DEFTREECODE (NE_EXPR, "ne_expr", '<', 2)
+/* Additional relational operators for floating point unordered. */
+DEFTREECODE (UNORDERED_EXPR, "unordered_expr", '<', 2)
+DEFTREECODE (ORDERED_EXPR, "ordered_expr", '<', 2)
+
+/* These are equivalent to unordered or ... */
+DEFTREECODE (UNLT_EXPR, "unlt_expr", '<', 2)
+DEFTREECODE (UNLE_EXPR, "unle_expr", '<', 2)
+DEFTREECODE (UNGT_EXPR, "ungt_expr", '<', 2)
+DEFTREECODE (UNGE_EXPR, "unge_expr", '<', 2)
+DEFTREECODE (UNEQ_EXPR, "uneq_expr", '<', 2)
+
/* Operations for Pascal sets. Not used now. */
DEFTREECODE (IN_EXPR, "in_expr", '2', 2)
DEFTREECODE (SET_LE_EXPR, "set_le_expr", '<', 2)
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. */
+/* 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)
/* & in C. Value is the address at which the operand's value resides.
DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", 'e', 2)
DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", 'e', 2)
+/* Used to implement `va_arg'. */
+DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", 'e', 1)
+
/* Evaluate operand 1. If and only if an exception is thrown during
the evaluation of operand 1, evaluate operand 2.
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)
+/* 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). */
+DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", 'e', 2)
+
+/* Used internally for cleanups in the implementation of TRY_FINALLY_EXPR.
+ (Specifically, it is created by expand_expr, not front-ends.)
+ Operand 0 is the rtx for the start of the subroutine we need to call.
+ 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)
\f
/* These types of expressions have no useful value,
and always have side effects. */
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.
+/* GOTO. Operand 0 is a LABEL_DECL node or an expression.
The type should be void and the value should be ignored. */
DEFTREECODE (GOTO_EXPR, "goto_expr", 's', 1)
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)
+/* A labeled block. Operand 0 is the label that will be generated to
+ mark the end of the block.
+ Operand 1 is the labeled block body. */
+DEFTREECODE (LABELED_BLOCK_EXPR, "labeled_block_expr", 'e', 2)
+
+/* Exit a labeled block, possibly returning a value. Operand 0 is a
+ LABELED_BLOCK_EXPR to exit. Operand 1 is the value to return. It
+ may be left null. */
+DEFTREECODE (EXIT_BLOCK_EXPR, "exit_block_expr", 'e', 2)
+
+/* Annotates a tree node (usually an expression) with source location
+ information: a file name (EXPR_WFL_FILENAME); a line number
+ (EXPR_WFL_LINENO); and column number (EXPR_WFL_COLNO). It is
+ expanded as the contained node (EXPR_WFL_NODE); a line note should
+ be emitted first if EXPR_WFL_EMIT_LINE_NOTE.
+ The third operand is only used in the Java front-end, and will
+ eventually be removed. */
+DEFTREECODE (EXPR_WITH_FILE_LOCATION, "expr_with_file_location", 'e', 3)
+
+/* 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. */
+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