1217309Snwhitehorn/* This file contains the definitions and documentation for the 2251843Sbapt tree codes used in GCC. 3217309Snwhitehorn Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005 4220749Snwhitehorn Free Software Foundation, Inc. 5217309Snwhitehorn 6251843SbaptThis file is part of GCC. 7217309Snwhitehorn 8217309SnwhitehornGCC is free software; you can redistribute it and/or modify it under 9217309Snwhitehornthe terms of the GNU General Public License as published by the Free 10217309SnwhitehornSoftware Foundation; either version 2, or (at your option) any later 11217309Snwhitehornversion. 12217309Snwhitehorn 13217309SnwhitehornGCC is distributed in the hope that it will be useful, but WITHOUT ANY 14217309SnwhitehornWARRANTY; without even the implied warranty of MERCHANTABILITY or 15217309SnwhitehornFITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16217309Snwhitehornfor more details. 17217309Snwhitehorn 18217309SnwhitehornYou should have received a copy of the GNU General Public License 19217309Snwhitehornalong with GCC; see the file COPYING. If not, write to the Free 20217309SnwhitehornSoftware Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 21217309Snwhitehorn02110-1301, USA. */ 22217309Snwhitehorn 23217309Snwhitehorn 24217309Snwhitehorn/* For tcc_references, tcc_expression, tcc_comparison, tcc_unary, 25217309Snwhitehorn tcc_binary, and tcc_statement nodes, which use struct tree_exp, the 26217309Snwhitehorn 4th element is the number of argument slots to allocate. This 27217309Snwhitehorn determines the size of the tree node object. Other nodes use 28217309Snwhitehorn different structures, and the size is determined by the tree_union 29217309Snwhitehorn member structure; the 4th element should be zero. Languages that 30217309Snwhitehorn define language-specific tcc_exceptional or tcc_constant codes must 31217309Snwhitehorn define the tree_size langhook to say how big they are. 32217309Snwhitehorn 33217309Snwhitehorn These tree codes have been sorted so that the macros in tree.h that 34217309Snwhitehorn check for various tree codes are optimized into range checks. This 35217309Snwhitehorn gives a measurable performance improvement. When adding a new 36217309Snwhitehorn code, consider its placement in relation to the other codes. */ 37217309Snwhitehorn 38217309Snwhitehorn/* Any erroneous construct is parsed into a node of this type. 39217309Snwhitehorn This type of node is accepted without complaint in all contexts 40217309Snwhitehorn by later parsing activities, to avoid multiple error messages 41217309Snwhitehorn for one error. 42217309Snwhitehorn No fields in these nodes are used except the TREE_CODE. */ 43217309SnwhitehornDEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0) 44217309Snwhitehorn 45217309Snwhitehorn/* Used to represent a name (such as, in the DECL_NAME of a decl node). 46217309Snwhitehorn Internally it looks like a STRING_CST node. 47217309Snwhitehorn There is only one IDENTIFIER_NODE ever made for any particular name. 48217309Snwhitehorn Use `get_identifier' to get it (or create it, the first time). */ 49217309SnwhitehornDEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0) 50217309Snwhitehorn 51217309Snwhitehorn/* Has the TREE_VALUE and TREE_PURPOSE fields. */ 52217309Snwhitehorn/* These nodes are made into lists by chaining through the 53217309Snwhitehorn TREE_CHAIN field. The elements of the list live in the 54217309Snwhitehorn TREE_VALUE fields, while TREE_PURPOSE fields are occasionally 55217309Snwhitehorn used as well to get the effect of Lisp association lists. */ 56217309SnwhitehornDEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0) 57217309Snwhitehorn 58217309Snwhitehorn/* These nodes contain an array of tree nodes. */ 59217309SnwhitehornDEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0) 60217309Snwhitehorn 61217309Snwhitehorn/* A symbol binding block. These are arranged in a tree, 62217309Snwhitehorn where the BLOCK_SUBBLOCKS field contains a chain of subblocks 63217309Snwhitehorn chained through the BLOCK_CHAIN field. 64217309Snwhitehorn BLOCK_SUPERCONTEXT points to the parent block. 65217309Snwhitehorn For a block which represents the outermost scope of a function, it 66217309Snwhitehorn points to the FUNCTION_DECL node. 67217309Snwhitehorn BLOCK_VARS points to a chain of decl nodes. 68217309Snwhitehorn BLOCK_TYPE_TAGS points to a chain of types which have their own names. 69217309Snwhitehorn BLOCK_CHAIN points to the next BLOCK at the same level. 70217309Snwhitehorn BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which 71217309Snwhitehorn this block is an instance of, or else is NULL to indicate that this 72217309Snwhitehorn block is not an instance of anything else. When non-NULL, the value 73217309Snwhitehorn could either point to another BLOCK node or it could point to a 74217309Snwhitehorn FUNCTION_DECL node (e.g. in the case of a block representing the 75217309Snwhitehorn outermost scope of a particular inlining of a function). 76217309Snwhitehorn BLOCK_ABSTRACT is nonzero if the block represents an abstract 77217309Snwhitehorn instance of a block (i.e. one which is nested within an abstract 78217309Snwhitehorn instance of an inline function). 79217309Snwhitehorn TREE_ASM_WRITTEN is nonzero if the block was actually referenced 80217309Snwhitehorn in the generated assembly. */ 81217309SnwhitehornDEFTREECODE (BLOCK, "block", tcc_exceptional, 0) 82217309Snwhitehorn 83217309Snwhitehorn/* Each data type is represented by a tree node whose code is one of 84217309Snwhitehorn the following: */ 85217309Snwhitehorn/* Each node that represents a data type has a component TYPE_SIZE 86217309Snwhitehorn containing a tree that is an expression for the size in bits. 87217309Snwhitehorn The TYPE_MODE contains the machine mode for values of this type. 88217309Snwhitehorn The TYPE_POINTER_TO field contains a type for a pointer to this type, 89217309Snwhitehorn or zero if no such has been created yet. 90217309Snwhitehorn The TYPE_NEXT_VARIANT field is used to chain together types 91217309Snwhitehorn that are variants made by type modifiers such as "const" and "volatile". 92217309Snwhitehorn The TYPE_MAIN_VARIANT field, in any member of such a chain, 93217309Snwhitehorn points to the start of the chain. 94217309Snwhitehorn The TYPE_NONCOPIED_PARTS field is a list specifying which parts 95217309Snwhitehorn of an object of this type should *not* be copied by assignment. 96217309Snwhitehorn The TREE_VALUE of each is a FIELD_DECL that should not be 97217309Snwhitehorn copied. The TREE_PURPOSE is an initial value for that field when 98217309Snwhitehorn an object of this type is initialized via an INIT_EXPR. It may 99217309Snwhitehorn be NULL if no special value is required. Even the things in this 100217309Snwhitehorn list are copied if the right-hand side of an assignment is known 101217309Snwhitehorn to be a complete object (rather than being, perhaps, a subobject 102217309Snwhitehorn of some other object.) The determination of what constitutes a 103217309Snwhitehorn complete object is done by fixed_type_p. 104217309Snwhitehorn The TYPE_NAME field contains info on the name used in the program 105217309Snwhitehorn for this type (for GDB symbol table output). It is either a 106217309Snwhitehorn TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE 107217309Snwhitehorn in the case of structs, unions or enums that are known with a tag, 108217309Snwhitehorn or zero for types that have no special name. 109217309Snwhitehorn The TYPE_CONTEXT for any sort of type which could have a name or 110217309Snwhitehorn which could have named members (e.g. tagged types in C/C++) will 111217309Snwhitehorn point to the node which represents the scope of the given type, or 112217309Snwhitehorn will be NULL_TREE if the type has "file scope". For most types, this 113217309Snwhitehorn will point to a BLOCK node or a FUNCTION_DECL node, but it could also 114217309Snwhitehorn point to a FUNCTION_TYPE node (for types whose scope is limited to the 115217309Snwhitehorn formal parameter list of some function type specification) or it 116217309Snwhitehorn could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node 117217309Snwhitehorn (for C++ "member" types). 118217309Snwhitehorn For non-tagged-types, TYPE_CONTEXT need not be set to anything in 119217309Snwhitehorn particular, since any type which is of some type category (e.g. 120217309Snwhitehorn an array type or a function type) which cannot either have a name 121217309Snwhitehorn itself or have named members doesn't really have a "scope" per se. 122220749Snwhitehorn The TREE_CHAIN field is used as a forward-references to names for 123220749Snwhitehorn ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes; 124217309Snwhitehorn see below. */ 125220749Snwhitehorn 126220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 127220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 128220749Snwhitehorn compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, CHAR_TYPE, 129220749Snwhitehorn INTEGER_TYPE, REAL_TYPE, POINTER_TYPE. */ 130220749Snwhitehorn 131220749Snwhitehorn/* An offset is a pointer relative to an object. 132220749Snwhitehorn The TREE_TYPE field is the type of the object at the offset. 133220749Snwhitehorn The TYPE_OFFSET_BASETYPE points to the node for the type of object 134220749Snwhitehorn that the offset is relative to. */ 135220749SnwhitehornDEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0) 136220749Snwhitehorn 137220749Snwhitehorn/* C enums. The type node looks just like an INTEGER_TYPE node. 138220749Snwhitehorn The symbols for the values of the enum type are defined by 139220749Snwhitehorn CONST_DECL nodes, but the type does not point to them; 140220749Snwhitehorn however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE 141220749Snwhitehorn is a name and the TREE_VALUE is the value (an INTEGER_CST node). */ 142220749Snwhitehorn/* A forward reference `enum foo' when no enum named foo is defined yet 143220749Snwhitehorn has zero (a null pointer) in its TYPE_SIZE. The tag name is in 144220749Snwhitehorn the TYPE_NAME field. If the type is later defined, the normal 145220749Snwhitehorn fields are filled in. 146220749Snwhitehorn RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are 147220749Snwhitehorn treated similarly. */ 148220749SnwhitehornDEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0) 149220749Snwhitehorn 150220749Snwhitehorn/* Boolean type (true or false are the only values). Looks like an 151220749Snwhitehorn INTEGRAL_TYPE. */ 152220749SnwhitehornDEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0) 153220749Snwhitehorn 154220749Snwhitehorn/* CHAR in Java; not used in C. Looks like an INTEGRAL_TYPE. */ 155220749SnwhitehornDEFTREECODE (CHAR_TYPE, "char_type", tcc_type, 0) 156220749Snwhitehorn 157220749Snwhitehorn/* Integer types in all languages, including char in C. 158220749Snwhitehorn Also used for sub-ranges of other discrete types. 159220749Snwhitehorn Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive) 160220749Snwhitehorn and TYPE_PRECISION (number of bits used by this type). 161220749Snwhitehorn In the case of a subrange type in Pascal, the TREE_TYPE 162220749Snwhitehorn of this will point at the supertype (another INTEGER_TYPE, 163220749Snwhitehorn or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE). 164220749Snwhitehorn Otherwise, the TREE_TYPE is zero. */ 165220749SnwhitehornDEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0) 166220749Snwhitehorn 167220749Snwhitehorn/* C's float and double. Different floating types are distinguished 168220749Snwhitehorn by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */ 169220749SnwhitehornDEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0) 170220749Snwhitehorn 171220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 172220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 173220749Snwhitehorn compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range 174220749Snwhitehorn overlaps the previous range of ordered types. */ 175220749Snwhitehorn 176220749Snwhitehorn/* All pointer-to-x types have code POINTER_TYPE. 177217309Snwhitehorn The TREE_TYPE points to the node for the type pointed to. */ 178220749SnwhitehornDEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0) 179217309Snwhitehorn 180220749Snwhitehorn/* A reference is like a pointer except that it is coerced 181217309Snwhitehorn automatically to the value it points to. Used in C++. */ 182217309SnwhitehornDEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0) 183220749Snwhitehorn 184220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 185220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 186220749Snwhitehorn compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */ 187217309Snwhitehorn 188220749Snwhitehorn/* Complex number types. The TREE_TYPE field is the data type 189220749Snwhitehorn of the real and imaginary parts. */ 190217309SnwhitehornDEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0) 191220749Snwhitehorn 192220749Snwhitehorn/* Vector types. The TREE_TYPE field is the data type of the vector 193220749Snwhitehorn elements. The TYPE_PRECISION field is the number of subparts of 194220749Snwhitehorn the vector. */ 195220749SnwhitehornDEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0) 196220749Snwhitehorn 197220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 198220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 199220749Snwhitehorn compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE. 200220749Snwhitehorn Note that this range overlaps the previous range. */ 201220749Snwhitehorn 202220749Snwhitehorn/* Types of arrays. Special fields: 203220749Snwhitehorn TREE_TYPE Type of an array element. 204220749Snwhitehorn TYPE_DOMAIN Type to index by. 205220749Snwhitehorn Its range of values specifies the array length. 206220749Snwhitehorn The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero 207220749Snwhitehorn and holds the type to coerce a value of that array type to in C. 208220749Snwhitehorn TYPE_STRING_FLAG indicates a string (in contrast to an array of chars) 209220749Snwhitehorn in languages (such as Chill) that make a distinction. */ 210220749Snwhitehorn/* Array types in C or Pascal */ 211220749SnwhitehornDEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0) 212220749Snwhitehorn 213220749Snwhitehorn/* Struct in C, or record in Pascal. */ 214220749Snwhitehorn/* Special fields: 215220749Snwhitehorn TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct, 216220749Snwhitehorn and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables, 217220749Snwhitehorn types and enumerators. 218220749Snwhitehorn A few may need to be added for Pascal. */ 219220749Snwhitehorn/* See the comment above, before ENUMERAL_TYPE, for how 220220749Snwhitehorn forward references to struct tags are handled in C. */ 221217309SnwhitehornDEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0) 222217309Snwhitehorn 223217309Snwhitehorn/* Union in C. Like a struct, except that the offsets of the fields 224217309Snwhitehorn will all be zero. */ 225217309Snwhitehorn/* See the comment above, before ENUMERAL_TYPE, for how 226217309Snwhitehorn forward references to union tags are handled in C. */ 227217309SnwhitehornDEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0) /* C union type */ 228217309Snwhitehorn 229217309Snwhitehorn/* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER 230220749Snwhitehorn in each FIELD_DECL determine what the union contains. The first 231220749Snwhitehorn field whose DECL_QUALIFIER expression is true is deemed to occupy 232220749Snwhitehorn the union. */ 233220749SnwhitehornDEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0) 234220749Snwhitehorn 235220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 236220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 237217309Snwhitehorn compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */ 238220749Snwhitehorn 239220749Snwhitehorn/* The void type in C */ 240217309SnwhitehornDEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0) 241217309Snwhitehorn 242217309Snwhitehorn/* Type of functions. Special fields: 243217309Snwhitehorn TREE_TYPE type of value returned. 244217309Snwhitehorn TYPE_ARG_TYPES list of types of arguments expected. 245217309Snwhitehorn this list is made of TREE_LIST nodes. 246217309Snwhitehorn Types of "Procedures" in languages where they are different from functions 247217309Snwhitehorn have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */ 248217309SnwhitehornDEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0) 249217309Snwhitehorn 250217309Snwhitehorn/* METHOD_TYPE is the type of a function which takes an extra first 251217309Snwhitehorn argument for "self", which is not present in the declared argument list. 252217309Snwhitehorn The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE 253217309Snwhitehorn is the type of "self". TYPE_ARG_TYPES is the real argument list, which 254217309Snwhitehorn includes the hidden argument for "self". */ 255217309SnwhitehornDEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0) 256217309Snwhitehorn 257217309Snwhitehorn/* This is a language-specific kind of type. 258217309Snwhitehorn Its meaning is defined by the language front end. 259217309Snwhitehorn layout_type does not know how to lay this out, 260217309Snwhitehorn so the front-end must do so manually. */ 261217309SnwhitehornDEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0) 262217309Snwhitehorn 263217309Snwhitehorn/* Expressions */ 264217309Snwhitehorn 265217309Snwhitehorn/* First, the constants. */ 266217309Snwhitehorn 267217309Snwhitehorn/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, 268217309Snwhitehorn 32 bits each, giving us a 64 bit constant capability. INTEGER_CST 269217309Snwhitehorn nodes can be shared, and therefore should be considered read only. 270217309Snwhitehorn They should be copied, before setting a flag such as 271217309Snwhitehorn TREE_OVERFLOW. If an INTEGER_CST has TREE_OVERFLOW or 272217309Snwhitehorn TREE_CONSTANT_OVERFLOW already set, it is known to be unique. 273217309Snwhitehorn INTEGER_CST nodes are created for the integral types, for pointer 274217309Snwhitehorn types and for vector and float types in some circumstances. */ 275217309SnwhitehornDEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0) 276217309Snwhitehorn 277217309Snwhitehorn/* Contents are in TREE_REAL_CST field. */ 278217309SnwhitehornDEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0) 279217309Snwhitehorn 280217309Snwhitehorn/* Contents are in TREE_REALPART and TREE_IMAGPART fields, 281217309Snwhitehorn whose contents are other constant nodes. */ 282217309SnwhitehornDEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0) 283217309Snwhitehorn 284217309Snwhitehorn/* Contents are in TREE_VECTOR_CST_ELTS field. */ 285217309SnwhitehornDEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0) 286217309Snwhitehorn 287251843Sbapt/* Contents are TREE_STRING_LENGTH and the actual contents of the string. */ 288251843SbaptDEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0) 289251843Sbapt 290251843Sbapt/* Declarations. All references to names are represented as ..._DECL 291251843Sbapt nodes. The decls in one binding context are chained through the 292251843Sbapt TREE_CHAIN field. Each DECL has a DECL_NAME field which contains 293251843Sbapt an IDENTIFIER_NODE. (Some decls, most often labels, may have zero 294251843Sbapt as the DECL_NAME). DECL_CONTEXT points to the node representing 295251843Sbapt the context in which this declaration has its scope. For 296251843Sbapt FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or 297251843Sbapt QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL, 298251843Sbapt PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this 299251843Sbapt points to either the FUNCTION_DECL for the containing function, the 300251843Sbapt RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or 301251843Sbapt a TRANSLATION_UNIT_DECL if the given decl has "file scope". 302251843Sbapt DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract) 303251843Sbapt ..._DECL node of which this decl is an (inlined or template expanded) 304251843Sbapt instance. 305251843Sbapt The TREE_TYPE field holds the data type of the object, when relevant. 306251843Sbapt LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field 307251843Sbapt contents are the type whose name is being declared. 308251843Sbapt The DECL_ALIGN, DECL_SIZE, 309251843Sbapt and DECL_MODE fields exist in decl nodes just as in type nodes. 310251843Sbapt They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes. 311251843Sbapt 312251843Sbapt DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for 313251843Sbapt the location. DECL_VOFFSET holds an expression for a variable 314251843Sbapt offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer). 315251843Sbapt These fields are relevant only in FIELD_DECLs and PARM_DECLs. 316251843Sbapt 317217309Snwhitehorn DECL_INITIAL holds the value to initialize a variable to, 318217309Snwhitehorn or the value of a constant. For a function, it holds the body 319217309Snwhitehorn (a node of type BLOCK representing the function's binding contour 320217309Snwhitehorn and whose body contains the function's statements.) For a LABEL_DECL 321217309Snwhitehorn in C, it is a flag, nonzero if the label's definition has been seen. 322217309Snwhitehorn 323217309Snwhitehorn PARM_DECLs use a special field: 324217309Snwhitehorn DECL_ARG_TYPE is the type in which the argument is actually 325217309Snwhitehorn passed, which may be different from its type within the function. 326217309Snwhitehorn 327251843Sbapt FUNCTION_DECLs use four special fields: 328217309Snwhitehorn DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. 329217309Snwhitehorn DECL_RESULT holds a RESULT_DECL node for the value of a function. 330217309Snwhitehorn The DECL_RTL field is 0 for a function that returns no value. 331217309Snwhitehorn (C functions returning void have zero here.) 332217309Snwhitehorn The TREE_TYPE field is the type in which the result is actually 333217309Snwhitehorn returned. This is usually the same as the return type of the 334220749Snwhitehorn FUNCTION_DECL, but it may be a wider integer type because of 335220749Snwhitehorn promotion. 336220749Snwhitehorn DECL_FUNCTION_CODE is a code number that is nonzero for 337220749Snwhitehorn built-in functions. Its value is an enum built_in_function 338220749Snwhitehorn that says which built-in function it is. 339220749Snwhitehorn 340220749Snwhitehorn DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE 341220749Snwhitehorn holds a line number. In some cases these can be the location of 342220749Snwhitehorn a reference, if no definition has been seen. 343220749Snwhitehorn 344220749Snwhitehorn DECL_ABSTRACT is nonzero if the decl represents an abstract instance 345220749Snwhitehorn of a decl (i.e. one which is nested within an abstract instance of a 346220749Snwhitehorn inline function. */ 347220749Snwhitehorn 348220749SnwhitehornDEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0) 349220749SnwhitehornDEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0) 350220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 351220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 352220749Snwhitehorn compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL, 353220749Snwhitehorn TYPE_DECL. */ 354220749SnwhitehornDEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0) 355220749SnwhitehornDEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0) 356220749SnwhitehornDEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0) 357220749SnwhitehornDEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0) 358220749SnwhitehornDEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0) 359220749SnwhitehornDEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0) 360220749Snwhitehorn 361220749Snwhitehorn/* A namespace declaration. Namespaces appear in DECL_CONTEXT of other 362220749Snwhitehorn _DECLs, providing a hierarchy of names. */ 363220749SnwhitehornDEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0) 364220749Snwhitehorn 365220749Snwhitehorn/* A translation unit. This is not technically a declaration, since it 366220749Snwhitehorn can't be looked up, but it's close enough. */ 367220749SnwhitehornDEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\ 368220749Snwhitehorn tcc_declaration, 0) 369220749Snwhitehorn 370220749Snwhitehorn/* References to storage. */ 371220749Snwhitehorn 372220749Snwhitehorn/* Value is structure or union component. 373220749Snwhitehorn Operand 0 is the structure or union (an expression). 374220749Snwhitehorn Operand 1 is the field (a node of type FIELD_DECL). 375220749Snwhitehorn Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured 376220749Snwhitehorn in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */ 377220749SnwhitehornDEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3) 378220749Snwhitehorn 379220749Snwhitehorn/* Reference to a group of bits within an object. Similar to COMPONENT_REF 380220749Snwhitehorn except the position is given explicitly rather than via a FIELD_DECL. 381220749Snwhitehorn Operand 0 is the structure or union expression; 382220749Snwhitehorn operand 1 is a tree giving the number of bits being referenced; 383220749Snwhitehorn operand 2 is a tree giving the position of the first referenced bit. 384220749Snwhitehorn The field can be either a signed or unsigned field; 385220749Snwhitehorn BIT_FIELD_REF_UNSIGNED says which. */ 386220749SnwhitehornDEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3) 387220749Snwhitehorn 388220749Snwhitehorn/* The ordering of the following codes is optimized for the checking 389220749Snwhitehorn macros in tree.h. Changing the order will degrade the speed of the 390220749Snwhitehorn compiler. INDIRECT_REF, ALIGN_INDIRECT_REF, MISALIGNED_INDIRECT_REF. */ 391220749Snwhitehorn 392220749Snwhitehorn/* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ 393220749SnwhitehornDEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1) 394220749Snwhitehorn 395220749Snwhitehorn/* Like above, but aligns the referenced address (i.e, if the address 396220749Snwhitehorn in P is not aligned on TYPE_ALIGN boundary, then &(*P) != P). */ 397220749SnwhitehornDEFTREECODE (ALIGN_INDIRECT_REF, "align_indirect_ref", tcc_reference, 1) 398220749Snwhitehorn 399220749Snwhitehorn/* Same as INDIRECT_REF, but also specifies the alignment of the referenced 400220749Snwhitehorn address: 401220749Snwhitehorn Operand 0 is the referenced address (a pointer); 402220749Snwhitehorn Operand 1 is an INTEGER_CST which represents the alignment of the address, 403220749Snwhitehorn or 0 if the alignment is unknown. */ 404220749SnwhitehornDEFTREECODE (MISALIGNED_INDIRECT_REF, "misaligned_indirect_ref", tcc_reference, 2) 405220749Snwhitehorn 406220749Snwhitehorn/* Array indexing. 407220749Snwhitehorn Operand 0 is the array; operand 1 is a (single) array index. 408220749Snwhitehorn Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index. 409220749Snwhitehorn Operand 3, if present, is the element size, measured in units of 410220749Snwhitehorn the alignment of the element type. */ 411220749SnwhitehornDEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4) 412220749Snwhitehorn 413220749Snwhitehorn/* Likewise, except that the result is a range ("slice") of the array. The 414220749Snwhitehorn starting index of the resulting array is taken from operand 1 and the size 415220749Snwhitehorn of the range is taken from the type of the expression. */ 416220749SnwhitehornDEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4) 417224014Snwhitehorn 418224014Snwhitehorn/* Used to represent lookup of runtime type dependent data. Often this is 419224014Snwhitehorn a reference to a vtable, but it needn't be. Operands are: 420217309Snwhitehorn OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use. 421217309Snwhitehorn OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is 422217309Snwhitehorn being performed. Through this the optimizers may be able to statically 423217309Snwhitehorn determine the dynamic type of the object. 424217309Snwhitehorn OBJ_TYPE_REF_TOKEN: Something front-end specific used to resolve the 425217309Snwhitehorn reference to something simpler, usually to the address of a DECL. 426217309Snwhitehorn Never touched by the middle-end. Good choices would be either an 427217309Snwhitehorn identifier or a vtable index. */ 428217309SnwhitehornDEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3) 429217309Snwhitehorn 430217309Snwhitehorn/* The exception object from the runtime. */ 431224014SnwhitehornDEFTREECODE (EXC_PTR_EXPR, "exc_ptr_expr", tcc_expression, 0) 432224014Snwhitehorn 433217309Snwhitehorn/* The filter object from the runtime. */ 434217309SnwhitehornDEFTREECODE (FILTER_EXPR, "filter_expr", tcc_expression, 0) 435217309Snwhitehorn 436220749Snwhitehorn/* Constructor: return an aggregate value made from specified components. 437220749Snwhitehorn In C, this is used only for structure and array initializers. 438217309Snwhitehorn The operand is a sequence of component values made out of a VEC of 439217309Snwhitehorn struct constructor_elt. 440217309Snwhitehorn 441220749Snwhitehorn For ARRAY_TYPE: 442217309Snwhitehorn The field INDEX of each constructor_elt is the corresponding index. 443217309Snwhitehorn If the index is a RANGE_EXPR, it is a short-hand for many nodes, 444217309Snwhitehorn one for each index in the range. (If the corresponding field VALUE 445217309Snwhitehorn has side-effects, they are evaluated once for each element. Wrap the 446217309Snwhitehorn value in a SAVE_EXPR if you want to evaluate side effects only once.) 447224014Snwhitehorn 448224014Snwhitehorn For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: 449217309Snwhitehorn The field INDEX of each node is a FIELD_DECL. */ 450220749SnwhitehornDEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0) 451217309Snwhitehorn 452220749Snwhitehorn/* The expression types are mostly straightforward, with the fourth argument 453217309Snwhitehorn of DEFTREECODE saying how many operands there are. 454217309Snwhitehorn Unless otherwise specified, the operands are expressions and the 455217309Snwhitehorn types of all the operands and the expression must all be the same. */ 456217309Snwhitehorn 457217309Snwhitehorn/* Contains two expressions to compute, one followed by the other. 458224014Snwhitehorn the first value is ignored. The second one's value is used. The 459224014Snwhitehorn type of the first expression need not agree with the other types. */ 460224014SnwhitehornDEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2) 461217309Snwhitehorn 462217309Snwhitehorn/* Assignment expression. Operand 0 is the what to set; 1, the new value. */ 463217309SnwhitehornDEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2) 464217309Snwhitehorn 465217309Snwhitehorn/* Initialization expression. Operand 0 is the variable to initialize; 466224014Snwhitehorn Operand 1 is the initializer. This differs from MODIFY_EXPR in that any 467224014Snwhitehorn reference to the referent of operand 0 within operand 1 is undefined. */ 468224014SnwhitehornDEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2) 469224014Snwhitehorn 470224014Snwhitehorn/* For TARGET_EXPR, operand 0 is the target of an initialization, 471224014Snwhitehorn operand 1 is the initializer for the target, which may be void 472224014Snwhitehorn if simply expanding it initializes the target. 473251843Sbapt operand 2 is the cleanup for this node, if any. 474251843Sbapt operand 3 is the saved initializer after this node has been 475251843Sbapt expanded once; this is so we can re-expand the tree later. */ 476224014SnwhitehornDEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4) 477224014Snwhitehorn 478224014Snwhitehorn/* Conditional expression ( ... ? ... : ... in C). 479224014Snwhitehorn Operand 0 is the condition. 480224014Snwhitehorn Operand 1 is the then-value. 481224014Snwhitehorn Operand 2 is the else-value. 482224014Snwhitehorn Operand 0 may be of any type. 483224014Snwhitehorn Operand 1 must have the same type as the entire expression, unless 484224014Snwhitehorn it unconditionally throws an exception, in which case it should 485224014Snwhitehorn have VOID_TYPE. The same constraints apply to operand 2. */ 486224014SnwhitehornDEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3) 487224014Snwhitehorn 488220749Snwhitehorn/* Vector conditional expression. It is like COND_EXPR, but with 489224014Snwhitehorn vector operands. 490224014Snwhitehorn 491224014Snwhitehorn A = VEC_COND_EXPR ( X < Y, B, C) 492224014Snwhitehorn 493224014Snwhitehorn means 494217309Snwhitehorn 495224014Snwhitehorn for (i=0; i<N; i++) 496217309Snwhitehorn A[i] = X[i] < Y[i] ? B[i] : C[i]; 497217309Snwhitehorn*/ 498224014SnwhitehornDEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3) 499224014Snwhitehorn 500224014Snwhitehorn/* Declare local variables, including making RTL and allocating space. 501224014Snwhitehorn BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables. 502224014Snwhitehorn BIND_EXPR_BODY is the body, the expression to be computed using 503224014Snwhitehorn the variables. The value of operand 1 becomes that of the BIND_EXPR. 504224014Snwhitehorn BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings 505224014Snwhitehorn for debugging purposes. If this BIND_EXPR is actually expanded, 506224014Snwhitehorn that sets the TREE_USED flag in the BLOCK. 507224014Snwhitehorn 508224014Snwhitehorn The BIND_EXPR is not responsible for informing parsers 509224014Snwhitehorn about these variables. If the body is coming from the input file, 510224014Snwhitehorn then the code that creates the BIND_EXPR is also responsible for 511224014Snwhitehorn informing the parser of the variables. 512224014Snwhitehorn 513224014Snwhitehorn If the BIND_EXPR is ever expanded, its TREE_USED flag is set. 514224014Snwhitehorn This tells the code for debugging symbol tables not to ignore the BIND_EXPR. 515224014Snwhitehorn If the BIND_EXPR should be output for debugging but will not be expanded, 516224014Snwhitehorn set the TREE_USED flag by hand. 517224014Snwhitehorn 518224014Snwhitehorn In order for the BIND_EXPR to be known at all, the code that creates it 519224014Snwhitehorn must also install it as a subblock in the tree of BLOCK 520224014Snwhitehorn nodes for the function. */ 521224014SnwhitehornDEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3) 522224014Snwhitehorn 523224014Snwhitehorn/* Function call. Operand 0 is the function. 524224014Snwhitehorn Operand 1 is the argument list, a list of expressions 525224014Snwhitehorn made out of a chain of TREE_LIST nodes. 526224014Snwhitehorn Operand 2 is the static chain argument, or NULL. */ 527224014SnwhitehornDEFTREECODE (CALL_EXPR, "call_expr", tcc_expression, 3) 528224014Snwhitehorn 529224014Snwhitehorn/* Specify a value to compute along with its corresponding cleanup. 530224014Snwhitehorn Operand 0 is the cleanup expression. 531224014Snwhitehorn The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, 532224014Snwhitehorn which must exist. This differs from TRY_CATCH_EXPR in that operand 1 533224014Snwhitehorn is always evaluated when cleanups are run. */ 534224014SnwhitehornDEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1) 535217309Snwhitehorn 536224014Snwhitehorn/* Specify a cleanup point. 537224014Snwhitehorn Operand 0 is an expression that may have cleanups. If it does, those 538224014Snwhitehorn cleanups are executed after the expression is expanded. 539224014Snwhitehorn 540224014Snwhitehorn Note that if the expression is a reference to storage, it is forced out 541224014Snwhitehorn of memory before the cleanups are run. This is necessary to handle 542224014Snwhitehorn cases where the cleanups modify the storage referenced; in the 543224014Snwhitehorn expression 't.i', if 't' is a struct with an integer member 'i' and a 544224014Snwhitehorn cleanup which modifies 'i', the value of the expression depends on 545217309Snwhitehorn whether the cleanup is run before or after 't.i' is evaluated. When 546224014Snwhitehorn expand_expr is run on 't.i', it returns a MEM. This is not good enough; 547224014Snwhitehorn the value of 't.i' must be forced out of memory. 548224014Snwhitehorn 549224014Snwhitehorn As a consequence, the operand of a CLEANUP_POINT_EXPR must not have 550224014Snwhitehorn BLKmode, because it will not be forced out of memory. */ 551217309SnwhitehornDEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1) 552224014Snwhitehorn 553224014Snwhitehorn/* The following two codes are used in languages that have types where 554224014Snwhitehorn some field in an object of the type contains a value that is used in 555224014Snwhitehorn the computation of another field's offset or size and/or the size of 556224014Snwhitehorn the type. The positions and/or sizes of fields can vary from object 557217309Snwhitehorn to object of the same type or even for one and the same object within 558217309Snwhitehorn its scope. 559251843Sbapt 560217309Snwhitehorn Record types with discriminants in Ada or schema types in Pascal are 561217309Snwhitehorn examples of such types. This mechanism is also used to create "fat 562217309Snwhitehorn pointers" for unconstrained array types in Ada; the fat pointer is a 563217309Snwhitehorn structure one of whose fields is a pointer to the actual array type 564217309Snwhitehorn and the other field is a pointer to a template, which is a structure 565217309Snwhitehorn containing the bounds of the array. The bounds in the type pointed 566217309Snwhitehorn to by the first field in the fat pointer refer to the values in the 567217309Snwhitehorn template. 568217309Snwhitehorn 569217309Snwhitehorn When you wish to construct such a type you need "self-references" 570217309Snwhitehorn that allow you to reference the object having this type from the 571217309Snwhitehorn TYPE node, i.e. without having a variable instantiating this type. 572217309Snwhitehorn 573217309Snwhitehorn Such a "self-references" is done using a PLACEHOLDER_EXPR. This is 574217309Snwhitehorn a node that will later be replaced with the object being referenced. 575217309Snwhitehorn Its type is that of the object and selects which object to use from 576217309Snwhitehorn a chain of references (see below). No other slots are used in the 577217309Snwhitehorn PLACEHOLDER_EXPR. 578217309Snwhitehorn 579217309Snwhitehorn For example, if your type FOO is a RECORD_TYPE with a field BAR, 580217309Snwhitehorn and you need the value of <variable>.BAR to calculate TYPE_SIZE 581217309Snwhitehorn (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR 582217309Snwhitehorn whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with 583217309Snwhitehorn the PLACEHOLDER_EXPR as the first operand (which has the correct 584217309Snwhitehorn type). Later, when the size is needed in the program, the back-end 585217309Snwhitehorn will find this PLACEHOLDER_EXPR and generate code to calculate the 586217309Snwhitehorn actual size at run-time. In the following, we describe how this 587217309Snwhitehorn calculation is done. 588217309Snwhitehorn 589217309Snwhitehorn When we wish to evaluate a size or offset, we check whether it contains a 590217309Snwhitehorn PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr 591217309Snwhitehorn passing both that tree and an expression within which the object may be 592217309Snwhitehorn found. The latter expression is the object itself in the simple case of 593217309Snwhitehorn an Ada record with discriminant, but it can be the array in the case of an 594217309Snwhitehorn unconstrained array. 595217309Snwhitehorn 596217309Snwhitehorn In the latter case, we need the fat pointer, because the bounds of 597217309Snwhitehorn the array can only be accessed from it. However, we rely here on the 598217309Snwhitehorn fact that the expression for the array contains the dereference of 599217309Snwhitehorn the fat pointer that obtained the array pointer. */ 600217309Snwhitehorn 601217309Snwhitehorn/* Denotes a record to later be substituted before evaluating this expression. 602217309Snwhitehorn The type of this expression is used to find the record to replace it. */ 603217309SnwhitehornDEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0) 604217309Snwhitehorn 605217309Snwhitehorn/* Simple arithmetic. */ 606217309SnwhitehornDEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2) 607217309SnwhitehornDEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2) 608217309SnwhitehornDEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2) 609217309Snwhitehorn 610217309Snwhitehorn/* Division for integer result that rounds the quotient toward zero. */ 611217309SnwhitehornDEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2) 612217309Snwhitehorn 613217309Snwhitehorn/* Division for integer result that rounds the quotient toward infinity. */ 614217309SnwhitehornDEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2) 615217309Snwhitehorn 616217309Snwhitehorn/* Division for integer result that rounds toward minus infinity. */ 617217309SnwhitehornDEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2) 618217309Snwhitehorn 619217309Snwhitehorn/* Division for integer result that rounds toward nearest integer. */ 620217309SnwhitehornDEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2) 621217309Snwhitehorn 622217309Snwhitehorn/* Four kinds of remainder that go with the four kinds of division. */ 623217309SnwhitehornDEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2) 624217309SnwhitehornDEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2) 625217309SnwhitehornDEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2) 626217309SnwhitehornDEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2) 627217309Snwhitehorn 628217309Snwhitehorn/* Division for real result. */ 629217309SnwhitehornDEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2) 630217309Snwhitehorn 631217309Snwhitehorn/* Division which is not supposed to need rounding. 632217309Snwhitehorn Used for pointer subtraction in C. */ 633217309SnwhitehornDEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2) 634217309Snwhitehorn 635217309Snwhitehorn/* Conversion of real to fixed point: four ways to round, 636217309Snwhitehorn like the four ways to divide. 637217309Snwhitehorn CONVERT_EXPR can also be used to convert a real to an integer, 638217309Snwhitehorn and that is what is used in languages that do not have ways of 639217309Snwhitehorn specifying which of these is wanted. Maybe these are not needed. */ 640217309SnwhitehornDEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1) 641217309SnwhitehornDEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", tcc_unary, 1) 642217309SnwhitehornDEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", tcc_unary, 1) 643217309SnwhitehornDEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", tcc_unary, 1) 644217309Snwhitehorn 645217309Snwhitehorn/* Conversion of an integer to a real. */ 646217309SnwhitehornDEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1) 647217309Snwhitehorn 648217309Snwhitehorn/* Unary negation. */ 649217309SnwhitehornDEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1) 650217309Snwhitehorn 651217309Snwhitehorn/* Minimum and maximum values. When used with floating point, if both 652217309Snwhitehorn operands are zeros, or if either operand is NaN, then it is unspecified 653217309Snwhitehorn which of the two operands is returned as the result. */ 654217309SnwhitehornDEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2) 655217309SnwhitehornDEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2) 656217309Snwhitehorn 657217309Snwhitehorn/* Represents the absolute value of the operand. 658217309Snwhitehorn 659217309Snwhitehorn An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The 660 operand of the ABS_EXPR must have the same type. */ 661DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1) 662 663/* Shift operations for shift and rotate. 664 Shift means logical shift if done on an 665 unsigned type, arithmetic shift if done on a signed type. 666 The second operand is the number of bits to 667 shift by; it need not be the same type as the first operand and result. 668 Note that the result is undefined if the second operand is larger 669 than or equal to the first operand's type size. */ 670DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2) 671DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2) 672DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2) 673DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2) 674 675/* Bitwise operations. Operands have same mode as result. */ 676DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2) 677DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2) 678DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2) 679DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1) 680 681/* ANDIF and ORIF allow the second operand not to be computed if the 682 value of the expression is determined from the first operand. AND, 683 OR, and XOR always compute the second operand whether its value is 684 needed or not (for side effects). The operand may have 685 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be 686 either zero or one. For example, a TRUTH_NOT_EXPR will never have 687 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be 688 used to compare the VAR_DECL to zero, thereby obtaining a node with 689 value zero or one. */ 690DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2) 691DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2) 692DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2) 693DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2) 694DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2) 695DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1) 696 697/* Relational operators. 698 `EQ_EXPR' and `NE_EXPR' are allowed for any types. 699 The others are allowed only for integer (or pointer or enumeral) 700 or real types. 701 In all cases the operands will have the same type, 702 and the value is always the type used by the language for booleans. */ 703DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2) 704DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2) 705DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2) 706DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2) 707DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2) 708DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2) 709 710/* Additional relational operators for floating point unordered. */ 711DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2) 712DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2) 713 714/* These are equivalent to unordered or ... */ 715DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2) 716DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2) 717DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2) 718DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2) 719DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2) 720 721/* This is the reverse of uneq_expr. */ 722DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2) 723 724DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2) 725 726/* Represents a conversion of type of a value. 727 All conversions, including implicit ones, must be 728 represented by CONVERT_EXPR or NOP_EXPR nodes. */ 729DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1) 730 731/* Represents a conversion expected to require no code to be generated. */ 732DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1) 733 734/* Value is same as argument, but guaranteed not an lvalue. */ 735DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1) 736 737/* Represents viewing something of one type as being of a second type. 738 This corresponds to an "Unchecked Conversion" in Ada and roughly to 739 the idiom *(type2 *)&X in C. The only operand is the value to be 740 viewed as being of another type. It is undefined if the type of the 741 input and of the expression have different sizes. 742 743 This code may also be used within the LHS of a MODIFY_EXPR, in which 744 case no actual data motion may occur. TREE_ADDRESSABLE will be set in 745 this case and GCC must abort if it could not do the operation without 746 generating insns. */ 747DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1) 748 749/* Represents something we computed once and will use multiple times. 750 First operand is that expression. After it is evaluated once, it 751 will be replaced by the temporary variable that holds the value. */ 752DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1) 753 754/* & in C. Value is the address at which the operand's value resides. 755 Operand may have any mode. Result mode is Pmode. */ 756DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1) 757 758/* Operand0 is a function constant; result is part N of a function 759 descriptor of type ptr_mode. */ 760DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2) 761 762/* Given two real or integer operands of the same type, 763 returns a complex value of the corresponding complex type. */ 764DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2) 765 766/* Complex conjugate of operand. Used only on complex types. */ 767DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1) 768 769/* Used only on an operand of complex type, these return 770 a value of the corresponding component type. */ 771DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1) 772DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1) 773 774/* Nodes for ++ and -- in C. 775 The second arg is how much to increment or decrement by. 776 For a pointer, it would be the size of the object pointed to. */ 777DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2) 778DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2) 779DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2) 780DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2) 781 782/* Used to implement `va_arg'. */ 783DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1) 784 785/* Evaluate operand 1. If and only if an exception is thrown during 786 the evaluation of operand 1, evaluate operand 2. 787 788 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated 789 on a normal or jump exit, only on an exception. */ 790DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2) 791 792/* Evaluate the first operand. 793 The second operand is a cleanup expression which is evaluated 794 on any exit (normal, exception, or jump out) from this expression. */ 795DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2) 796 797/* These types of expressions have no useful value, 798 and always have side effects. */ 799 800/* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */ 801DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1) 802 803/* A label definition, encapsulated as a statement. 804 Operand 0 is the LABEL_DECL node for the label that appears here. 805 The type should be void and the value should be ignored. */ 806DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1) 807 808/* GOTO. Operand 0 is a LABEL_DECL node or an expression. 809 The type should be void and the value should be ignored. */ 810DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1) 811 812/* RETURN. Evaluates operand 0, then returns from the current function. 813 Presumably that operand is an assignment that stores into the 814 RESULT_DECL that hold the value to be returned. 815 The operand may be null. 816 The type should be void and the value should be ignored. */ 817DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1) 818 819/* Exit the inner most loop conditionally. Operand 0 is the condition. 820 The type should be void and the value should be ignored. */ 821DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1) 822 823/* A loop. Operand 0 is the body of the loop. 824 It must contain an EXIT_EXPR or is an infinite loop. 825 The type should be void and the value should be ignored. */ 826DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1) 827 828/* Switch expression. 829 830 TREE_TYPE is the original type of the condition, before any 831 language required type conversions. It may be NULL, in which case 832 the original type and final types are assumed to be the same. 833 834 Operand 0 is the expression used to perform the branch, 835 Operand 1 is the body of the switch, which probably contains 836 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2 837 must not be NULL. 838 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs 839 of all the cases. */ 840DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3) 841 842/* Used to represent a case label. The operands are CASE_LOW and 843 CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a 844 'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case 845 label. CASE_LABEL is the corresponding LABEL_DECL. */ 846DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 3) 847 848/* RESX. Resume execution after an exception. Operand 0 is a 849 number indicating the exception region that is being left. */ 850DEFTREECODE (RESX_EXPR, "resx_expr", tcc_statement, 1) 851 852/* Used to represent an inline assembly statement. ASM_STRING returns a 853 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS, 854 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers 855 for the statement. */ 856DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 4) 857 858/* Variable references for SSA analysis. New SSA names are created every 859 time a variable is assigned a new value. The SSA builder uses SSA_NAME 860 nodes to implement SSA versioning. */ 861DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0) 862 863/* SSA PHI operator. PHI_RESULT is the new SSA_NAME node created by 864 the PHI node. PHI_ARG_LENGTH is the number of arguments. 865 PHI_ARG_ELT returns the Ith tuple <ssa_name, edge> from the 866 argument list. Each tuple contains the incoming reaching 867 definition (SSA_NAME node) and the edge via which that definition 868 is coming through. */ 869DEFTREECODE (PHI_NODE, "phi_node", tcc_exceptional, 0) 870 871/* Used to represent a typed exception handler. CATCH_TYPES is the type (or 872 list of types) handled, and CATCH_BODY is the code for the handler. */ 873DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2) 874 875/* Used to represent an exception specification. EH_FILTER_TYPES is a list 876 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on 877 failure. EH_FILTER_MUST_NOT_THROW controls which range type to use when 878 expanding. */ 879DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2) 880 881/* Node used for describing a property that is known at compile 882 time. */ 883DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0) 884 885/* Node used for describing a property that is not known at compile 886 time. */ 887DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0) 888 889/* Polynomial chains of recurrences. 890 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */ 891DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3) 892 893/* Used to chain children of container statements together. 894 Use the interface in tree-iterator.h to access this node. */ 895DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0) 896 897/* Value handles. Artificial nodes to represent expressions in 898 partial redundancy elimination (tree-ssa-pre.c). These nodes are 899 used for expression canonicalization. If two expressions compute 900 the same value, they will be assigned the same value handle. */ 901DEFTREECODE (VALUE_HANDLE, "value_handle", tcc_exceptional, 0) 902 903/* Predicate assertion. Artificial expression generated by the optimizers 904 to keep track of predicate values. This expression may only appear on 905 the RHS of assignments. 906 907 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer 908 two things: 909 910 1- X is a copy of Y. 911 2- EXPR is a GIMPLE conditional expression (as defined by 912 is_gimple_condexpr) and is known to be true. 913 914 The type of the expression is the same as Y. */ 915DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2) 916 917/* Base class information. Holds information about a class as a 918 baseclass of itself or another class. */ 919DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0) 920 921/* Records the size for an expression of variable size type. This is 922 for use in contexts in which we are accessing the entire object, 923 such as for a function call, or block copy. 924 Operand 0 is the real expression. 925 Operand 1 is the size of the type in the expression. */ 926DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2) 927 928/* Extract elements from two input vectors Operand 0 and Operand 1 929 size VS, according to the offset OFF defined by Operand 2 as 930 follows: 931 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to 932 the first OFF elements of the vector OP1. 933 If OFF == 0, then the returned vector is OP1. 934 On different targets OFF may take different forms; It can be an address, in 935 which case its low log2(VS)-1 bits define the offset, or it can be a mask 936 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */ 937DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3) 938 939/* Low-level memory addressing. Operands are SYMBOL (static or global 940 variable), BASE (register), INDEX (register), STEP (integer constant), 941 OFFSET (integer constant). Corresponding address is 942 SYMBOL + BASE + STEP * INDEX + OFFSET. Only variations and values valid on 943 the target are allowed. 944 945 The sixth argument is the reference to the original memory access, which 946 is preserved for the purposes of the RTL alias analysis. The seventh 947 argument is a tag representing results of the tree level alias analysis. */ 948 949DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 7) 950 951/* Reduction operations. 952 Operations that take a vector of elements and "reduce" it to a scalar 953 result (e.g. summing the elements of the vector, finding the minimum over 954 the vector elements, etc). 955 Operand 0 is a vector; the first element in the vector has the result. 956 Operand 1 is a vector. */ 957DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1) 958DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1) 959DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1) 960 961/* Whole vector left/right shift in bits. 962 Operand 0 is a vector to be shifted. 963 Operand 1 is an integer shift amount in bits. */ 964DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2) 965DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2) 966 967/* 968Local variables: 969mode:c 970End: 971*/ 972