| /* This file contains the definitions and documentation for the |
| 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 GCC. |
| |
| 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. |
| |
| 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 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: |
| 'x' for an exceptional code (fits no category). |
| 't' for a type object code. |
| 'b' for a lexical block. |
| 'c' for codes for constants. |
| 'd' for codes for declarations (also serving as variable refs). |
| 'r' for codes for references to storage. |
| '<' for codes for comparison expressions. |
| '1' for codes for unary arithmetic expressions. |
| '2' for codes for binary arithmetic expressions. |
| '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', 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 |
| by later parsing activities, to avoid multiple error messages |
| for one error. |
| No fields in these nodes are used except the TREE_CODE. */ |
| DEFTREECODE (ERROR_MARK, "error_mark", 'x', 0) |
| |
| /* Used to represent a name (such as, in the DECL_NAME of a decl node). |
| 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', 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', 0) |
| |
| /* These nodes contain an array of tree nodes. */ |
| 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 |
| chained through the BLOCK_CHAIN field. |
| BLOCK_SUPERCONTEXT points to the parent block. |
| For a block which represents the outermost scope of a function, it |
| points to the FUNCTION_DECL node. |
| BLOCK_VARS points to a chain of decl nodes. |
| BLOCK_TYPE_TAGS points to a chain of types which have their own names. |
| BLOCK_CHAIN points to the next BLOCK at the same level. |
| BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which |
| this block is an instance of, or else is NULL to indicate that this |
| block is not an instance of anything else. When non-NULL, the value |
| 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 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 nonzero if the block was actually referenced |
| in the generated assembly. */ |
| DEFTREECODE (BLOCK, "block", 'b', 0) |
| |
| /* Each data type is represented by a tree node whose code is one of |
| the following: */ |
| /* Each node that represents a data type has a component TYPE_SIZE |
| containing a tree that is an expression for the size in bits. |
| The TYPE_MODE contains the machine mode for values of this type. |
| The TYPE_POINTER_TO field contains a type for a pointer to this type, |
| or zero if no such has been created yet. |
| The TYPE_NEXT_VARIANT field is used to chain together types |
| that are variants made by type modifiers such as "const" and "volatile". |
| The TYPE_MAIN_VARIANT field, in any member of such a chain, |
| 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_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 |
| in the case of structs, unions or enums that are known with a tag, |
| or zero for types that have no special name. |
| The TYPE_CONTEXT for any sort of type which could have a name or |
| which could have named members (e.g. tagged types in C/C++) will |
| point to the node which represents the scope of the given type, or |
| will be NULL_TREE if the type has "file scope". For most types, this |
| will point to a BLOCK node or a FUNCTION_DECL node, but it could also |
| point to a FUNCTION_TYPE node (for types whose scope is limited to the |
| formal parameter list of some function type specification) or it |
| could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node |
| (for C++ "member" types). |
| For non-tagged-types, TYPE_CONTEXT need not be set to anything in |
| particular, since any type which is of some type category (e.g. |
| an array type or a function type) which cannot either have a name |
| itself or have named members doesn't really have a "scope" per se. |
| The TREE_CHAIN field is used as a forward-references to names for |
| ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes; |
| see below. */ |
| |
| DEFTREECODE (VOID_TYPE, "void_type", 't', 0) /* The void type in C */ |
| |
| /* Integer types in all languages, including char in C. |
| Also used for sub-ranges of other discrete types. |
| Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive) |
| and TYPE_PRECISION (number of bits used by this type). |
| In the case of a subrange type in Pascal, the TREE_TYPE |
| of this will point at the supertype (another INTEGER_TYPE, |
| or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE). |
| Otherwise, the TREE_TYPE is zero. */ |
| DEFTREECODE (INTEGER_TYPE, "integer_type", 't', 0) |
| |
| /* C's float and double. Different floating types are distinguished |
| by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */ |
| DEFTREECODE (REAL_TYPE, "real_type", 't', 0) |
| |
| /* Complex number types. The TREE_TYPE field is the data type |
| 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; |
| however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE |
| is a name and the TREE_VALUE is the value (an INTEGER_CST node). */ |
| /* A forward reference `enum foo' when no enum named foo is defined yet |
| has zero (a null pointer) in its TYPE_SIZE. The tag name is in |
| the TYPE_NAME field. If the type is later defined, the normal |
| fields are filled in. |
| RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are |
| treated similarly. */ |
| DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", 't', 0) |
| |
| /* Pascal's boolean type (true or false are the only values); |
| no special fields needed. */ |
| DEFTREECODE (BOOLEAN_TYPE, "boolean_type", 't', 0) |
| |
| /* CHAR in Pascal; not used in C. |
| No special fields needed. */ |
| DEFTREECODE (CHAR_TYPE, "char_type", 't', 0) |
| |
| /* All pointer-to-x types have code POINTER_TYPE. |
| The TREE_TYPE points to the node for the type pointed to. */ |
| DEFTREECODE (POINTER_TYPE, "pointer_type", 't', 0) |
| |
| /* An offset is a pointer relative to an object. |
| The TREE_TYPE field is the type of the object at the offset. |
| The TYPE_OFFSET_BASETYPE points to the node for the type of object |
| that the offset is relative to. */ |
| DEFTREECODE (OFFSET_TYPE, "offset_type", 't', 0) |
| |
| /* A reference is like a pointer except that it is coerced |
| automatically to the value it points to. Used in C++. */ |
| DEFTREECODE (REFERENCE_TYPE, "reference_type", 't', 0) |
| |
| /* METHOD_TYPE is the type of a function which takes an extra first |
| argument for "self", which is not present in the declared argument list. |
| The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE |
| is the type of "self". TYPE_ARG_TYPES is the real argument list, which |
| includes the hidden argument for "self". */ |
| DEFTREECODE (METHOD_TYPE, "method_type", 't', 0) |
| |
| /* Used for Pascal; details not determined right now. */ |
| DEFTREECODE (FILE_TYPE, "file_type", 't', 0) |
| |
| /* Types of arrays. Special fields: |
| TREE_TYPE Type of an array element. |
| TYPE_DOMAIN Type to index by. |
| Its range of values specifies the array length. |
| 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. */ |
| /* 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. */ |
| DEFTREECODE (SET_TYPE, "set_type", 't', 0) |
| |
| /* Struct in C, or record in Pascal. */ |
| /* Special fields: |
| TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct, |
| and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables, |
| types and enumerators. |
| A few may need to be added for Pascal. */ |
| /* See the comment above, before ENUMERAL_TYPE, for how |
| forward references to struct tags are handled in C. */ |
| DEFTREECODE (RECORD_TYPE, "record_type", 't', 0) |
| |
| /* Union in C. Like a struct, except that the offsets of the fields |
| will all be zero. */ |
| /* See the comment above, before ENUMERAL_TYPE, for how |
| forward references to union tags are handled in C. */ |
| DEFTREECODE (UNION_TYPE, "union_type", 't', 0) /* C union type */ |
| |
| /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER |
| in each FIELD_DECL determine what the union contains. The first |
| field whose DECL_QUALIFIER expression is true is deemed to occupy |
| the union. */ |
| DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", 't', 0) |
| |
| /* Type of functions. Special fields: |
| TREE_TYPE type of value returned. |
| TYPE_ARG_TYPES list of types of arguments expected. |
| this list is made of TREE_LIST nodes. |
| Types of "Procedures" in languages where they are different from functions |
| have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */ |
| DEFTREECODE (FUNCTION_TYPE, "function_type", 't', 0) |
| |
| /* This is a language-specific kind of type. |
| Its meaning is defined by the language front end. |
| layout_type does not know how to lay this out, |
| so the front-end must do so manually. */ |
| DEFTREECODE (LANG_TYPE, "lang_type", 't', 0) |
| |
| /* Expressions */ |
| |
| /* First, the constants. */ |
| |
| /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, |
| 32 bits each, giving us a 64 bit constant capability. |
| 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', 0) |
| |
| /* 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. */ |
| 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. |
| The TREE_TYPE field holds the data type of the object, when relevant. |
| LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field |
| contents are the type whose name is being declared. |
| The DECL_ALIGN, DECL_SIZE, |
| 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_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, |
| or the value of a constant. For a function, it holds the body |
| (a node of type BLOCK representing the function's binding contour |
| and whose body contains the function's statements.) For a LABEL_DECL |
| in C, it is a flag, nonzero if the label's definition has been seen. |
| |
| PARM_DECLs use a special field: |
| DECL_ARG_TYPE is the type in which the argument is actually |
| passed, which may be different from its type within the function. |
| |
| FUNCTION_DECLs use four special fields: |
| DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. |
| 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.) |
| 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. |
| |
| DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE |
| holds a line number. In some cases these can be the location of |
| a reference, if no definition has been seen. |
| |
| 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. */ |
| |
| DEFTREECODE (FUNCTION_DECL, "function_decl", 'd', 0) |
| DEFTREECODE (LABEL_DECL, "label_decl", 'd', 0) |
| DEFTREECODE (CONST_DECL, "const_decl", 'd', 0) |
| DEFTREECODE (TYPE_DECL, "type_decl", 'd', 0) |
| DEFTREECODE (VAR_DECL, "var_decl", 'd', 0) |
| DEFTREECODE (PARM_DECL, "parm_decl", 'd', 0) |
| DEFTREECODE (RESULT_DECL, "result_decl", 'd', 0) |
| DEFTREECODE (FIELD_DECL, "field_decl", 'd', 0) |
| |
| /* 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) |
| |
| /* References to storage. */ |
| |
| /* Value is structure or union component. |
| Operand 0 is the structure or union (an expression); |
| operand 1 is the field (a node of type FIELD_DECL). */ |
| DEFTREECODE (COMPONENT_REF, "component_ref", 'r', 2) |
| |
| /* Reference to a group of bits within an object. Similar to COMPONENT_REF |
| except the position is given explicitly rather than via a FIELD_DECL. |
| Operand 0 is the structure or union expression; |
| operand 1 is a tree giving the number of bits being referenced; |
| operand 2 is a tree giving the position of the first referenced bit. |
| The field can be either a signed or unsigned field; |
| TREE_UNSIGNED says which. */ |
| DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", 'r', 3) |
| |
| /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ |
| DEFTREECODE (INDIRECT_REF, "indirect_ref", 'r', 1) |
| |
| /* Pascal `^` on a file. One operand, an expression for the file. */ |
| DEFTREECODE (BUFFER_REF, "buffer_ref", 'r', 1) |
| |
| /* 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 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. |
| If the TREE_PURPOSE is a RANGE_EXPR, it is a short-hand for many nodes, |
| one for each index in the range. (If the corresponding TREE_VALUE |
| has side-effects, they are evaluated once for each element. Wrap the |
| value in a SAVE_EXPR if you want to evaluate side effects only once.) |
| |
| For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: |
| The TREE_PURPOSE of each node is a FIELD_DECL. |
| |
| For SET_TYPE: |
| 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', 1) |
| |
| /* The expression types are mostly straightforward, with the fourth argument |
| of DEFTREECODE saying how many operands there are. |
| Unless otherwise specified, the operands are expressions and the |
| types of all the operands and the expression must all be the same. */ |
| |
| /* Contains two expressions to compute, one followed by the other. |
| the first value is ignored. The second one's value is used. The |
| type of the first expression need not agree with the other types. */ |
| DEFTREECODE (COMPOUND_EXPR, "compound_expr", 'e', 2) |
| |
| /* 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. |
| 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. |
| 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. */ |
| 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 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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) |
| |
| /* 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) |
| |
| /* 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. |
| 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 (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_NOT_EXPR, "bit_not_expr", '1', 1) |
| |
| /* 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 (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) |
| |
| /* 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) |
| 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 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, |
| 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. 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 (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 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) |
| |
| /* 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) |
| |
| /* 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. |
| |
| 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) |
| |
| /* Evaluate the first operand. |
| 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. |
| (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) |
| |
| /* 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 or an expression. |
| 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) |
| |
| /* 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 |
| End: |
| */ |