1 | /* This file contains the definitions and documentation for the |
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2 | tree codes used in the GNU C compiler. |
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3 | Copyright (C) 1987, 1988, 1993, 1995, 1997 Free Software Foundation, Inc. |
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4 | |
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5 | This file is part of GNU CC. |
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6 | |
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7 | GNU CC is free software; you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation; either version 2, or (at your option) |
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10 | any later version. |
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11 | |
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12 | GNU CC is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |
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17 | You should have received a copy of the GNU General Public License |
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18 | along with GNU CC; see the file COPYING. If not, write to |
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19 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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20 | Boston, MA 02111-1307, USA. */ |
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21 | |
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22 | |
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23 | /* The third argument can be: |
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24 | "x" for an exceptional code (fits no category). |
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25 | "t" for a type object code. |
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26 | "b" for a lexical block. |
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27 | "c" for codes for constants. |
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28 | "d" for codes for declarations (also serving as variable refs). |
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29 | "r" for codes for references to storage. |
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30 | "<" for codes for comparison expressions. |
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31 | "1" for codes for unary arithmetic expressions. |
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32 | "2" for codes for binary arithmetic expressions. |
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33 | "s" for codes for expressions with inherent side effects. |
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34 | "e" for codes for other kinds of expressions. */ |
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35 | |
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36 | /* For `r', `e', `<', `1', `2', `s' and `x' nodes, |
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37 | the 4th element is the number of argument slots to allocate. |
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38 | This determines the size of the tree node object. */ |
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39 | |
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40 | /* Any erroneous construct is parsed into a node of this type. |
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41 | This type of node is accepted without complaint in all contexts |
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42 | by later parsing activities, to avoid multiple error messages |
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43 | for one error. |
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44 | No fields in these nodes are used except the TREE_CODE. */ |
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45 | DEFTREECODE (ERROR_MARK, "error_mark", "x", 0) |
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46 | |
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47 | /* Used to represent a name (such as, in the DECL_NAME of a decl node). |
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48 | Internally it looks like a STRING_CST node. |
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49 | There is only one IDENTIFIER_NODE ever made for any particular name. |
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50 | Use `get_identifier' to get it (or create it, the first time). */ |
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51 | DEFTREECODE (IDENTIFIER_NODE, "identifier_node", "x", -1) |
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52 | |
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53 | /* Used to hold information to identify an operator (or combination |
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54 | of two operators) considered as a `noun' rather than a `verb'. |
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55 | The first operand is encoded in the TREE_TYPE field. */ |
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56 | DEFTREECODE (OP_IDENTIFIER, "op_identifier", "x", 2) |
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57 | |
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58 | /* Has the TREE_VALUE and TREE_PURPOSE fields. */ |
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59 | /* These nodes are made into lists by chaining through the |
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60 | TREE_CHAIN field. The elements of the list live in the |
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61 | TREE_VALUE fields, while TREE_PURPOSE fields are occasionally |
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62 | used as well to get the effect of Lisp association lists. */ |
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63 | DEFTREECODE (TREE_LIST, "tree_list", "x", 2) |
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64 | |
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65 | /* These nodes contain an array of tree nodes. */ |
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66 | DEFTREECODE (TREE_VEC, "tree_vec", "x", 2) |
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67 | |
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68 | /* A symbol binding block. These are arranged in a tree, |
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69 | where the BLOCK_SUBBLOCKS field contains a chain of subblocks |
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70 | chained through the BLOCK_CHAIN field. |
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71 | BLOCK_SUPERCONTEXT points to the parent block. |
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72 | For a block which represents the outermost scope of a function, it |
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73 | points to the FUNCTION_DECL node. |
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74 | BLOCK_VARS points to a chain of decl nodes. |
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75 | BLOCK_TYPE_TAGS points to a chain of types which have their own names. |
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76 | BLOCK_CHAIN points to the next BLOCK at the same level. |
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77 | BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which |
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78 | this block is an instance of, or else is NULL to indicate that this |
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79 | block is not an instance of anything else. When non-NULL, the value |
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80 | could either point to another BLOCK node or it could point to a |
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81 | FUNCTION_DECL node (e.g. in the case of a block representing the |
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82 | outermost scope of a particular inlining of a function). |
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83 | BLOCK_ABSTRACT is non-zero if the block represents an abstract |
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84 | instance of a block (i.e. one which is nested within an abstract |
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85 | instance of a inline function. */ |
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86 | DEFTREECODE (BLOCK, "block", "b", 0) |
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87 | |
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88 | /* Each data type is represented by a tree node whose code is one of |
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89 | the following: */ |
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90 | /* Each node that represents a data type has a component TYPE_SIZE |
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91 | containing a tree that is an expression for the size in bits. |
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92 | The TYPE_MODE contains the machine mode for values of this type. |
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93 | The TYPE_POINTER_TO field contains a type for a pointer to this type, |
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94 | or zero if no such has been created yet. |
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95 | The TYPE_NEXT_VARIANT field is used to chain together types |
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96 | that are variants made by type modifiers such as "const" and "volatile". |
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97 | The TYPE_MAIN_VARIANT field, in any member of such a chain, |
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98 | points to the start of the chain. |
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99 | The TYPE_NONCOPIED_PARTS field is a list specifying which parts |
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100 | of an object of this type should *not* be copied by assignment. |
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101 | The TREE_PURPOSE of each element is the offset of the part |
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102 | and the TREE_VALUE is the size in bits of the part. |
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103 | The TYPE_NAME field contains info on the name used in the program |
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104 | for this type (for GDB symbol table output). It is either a |
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105 | TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE |
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106 | in the case of structs, unions or enums that are known with a tag, |
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107 | or zero for types that have no special name. |
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108 | The TYPE_CONTEXT for any sort of type which could have a name or |
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109 | which could have named members (e.g. tagged types in C/C++) will |
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110 | point to the node which represents the scope of the given type, or |
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111 | will be NULL_TREE if the type has "file scope". For most types, this |
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112 | will point to a BLOCK node or a FUNCTION_DECL node, but it could also |
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113 | point to a FUNCTION_TYPE node (for types whose scope is limited to the |
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114 | formal parameter list of some function type specification) or it |
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115 | could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node |
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116 | (for C++ "member" types). |
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117 | For non-tagged-types, TYPE_CONTEXT need not be set to anything in |
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118 | particular, since any type which is of some type category (e.g. |
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119 | an array type or a function type) which cannot either have a name |
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120 | itself or have named members doesn't really have a "scope" per se. |
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121 | The TREE_CHAIN field is used as a forward-references to names for |
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122 | ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes; |
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123 | see below. */ |
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124 | |
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125 | DEFTREECODE (VOID_TYPE, "void_type", "t", 0) /* The void type in C */ |
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126 | |
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127 | /* Integer types in all languages, including char in C. |
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128 | Also used for sub-ranges of other discrete types. |
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129 | Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive) |
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130 | and TYPE_PRECISION (number of bits used by this type). |
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131 | In the case of a subrange type in Pascal, the TREE_TYPE |
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132 | of this will point at the supertype (another INTEGER_TYPE, |
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133 | or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE). |
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134 | Otherwise, the TREE_TYPE is zero. */ |
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135 | DEFTREECODE (INTEGER_TYPE, "integer_type", "t", 0) |
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136 | |
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137 | /* C's float and double. Different floating types are distinguished |
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138 | by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */ |
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139 | DEFTREECODE (REAL_TYPE, "real_type", "t", 0) |
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140 | |
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141 | /* Complex number types. The TREE_TYPE field is the data type |
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142 | of the real and imaginary parts. */ |
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143 | DEFTREECODE (COMPLEX_TYPE, "complex_type", "t", 0) |
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144 | |
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145 | /* C enums. The type node looks just like an INTEGER_TYPE node. |
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146 | The symbols for the values of the enum type are defined by |
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147 | CONST_DECL nodes, but the type does not point to them; |
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148 | however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE |
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149 | is a name and the TREE_VALUE is the value (an INTEGER_CST node). */ |
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150 | /* A forward reference `enum foo' when no enum named foo is defined yet |
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151 | has zero (a null pointer) in its TYPE_SIZE. The tag name is in |
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152 | the TYPE_NAME field. If the type is later defined, the normal |
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153 | fields are filled in. |
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154 | RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are |
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155 | treated similarly. */ |
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156 | DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", "t", 0) |
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157 | |
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158 | /* Pascal's boolean type (true or false are the only values); |
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159 | no special fields needed. */ |
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160 | DEFTREECODE (BOOLEAN_TYPE, "boolean_type", "t", 0) |
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161 | |
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162 | /* CHAR in Pascal; not used in C. |
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163 | No special fields needed. */ |
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164 | DEFTREECODE (CHAR_TYPE, "char_type", "t", 0) |
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165 | |
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166 | /* All pointer-to-x types have code POINTER_TYPE. |
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167 | The TREE_TYPE points to the node for the type pointed to. */ |
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168 | DEFTREECODE (POINTER_TYPE, "pointer_type", "t", 0) |
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169 | |
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170 | /* An offset is a pointer relative to an object. |
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171 | The TREE_TYPE field is the type of the object at the offset. |
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172 | The TYPE_OFFSET_BASETYPE points to the node for the type of object |
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173 | that the offset is relative to. */ |
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174 | DEFTREECODE (OFFSET_TYPE, "offset_type", "t", 0) |
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175 | |
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176 | /* A reference is like a pointer except that it is coerced |
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177 | automatically to the value it points to. Used in C++. */ |
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178 | DEFTREECODE (REFERENCE_TYPE, "reference_type", "t", 0) |
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179 | |
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180 | /* METHOD_TYPE is the type of a function which takes an extra first |
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181 | argument for "self", which is not present in the declared argument list. |
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182 | The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE |
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183 | is the type of "self". TYPE_ARG_TYPES is the real argument list, which |
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184 | includes the hidden argument for "self". */ |
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185 | DEFTREECODE (METHOD_TYPE, "method_type", "t", 0) |
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186 | |
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187 | /* Used for Pascal; details not determined right now. */ |
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188 | DEFTREECODE (FILE_TYPE, "file_type", "t", 0) |
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189 | |
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190 | /* Types of arrays. Special fields: |
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191 | TREE_TYPE Type of an array element. |
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192 | TYPE_DOMAIN Type to index by. |
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193 | Its range of values specifies the array length. |
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194 | TYPE_SEP Expression for units from one elt to the next. |
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195 | TYPE_SEP_UNIT Number of bits in a unit for previous. |
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196 | The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero |
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197 | and holds the type to coerce a value of that array type to in C. |
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198 | TYPE_STRING_FLAG indicates a string (in contrast to an array of chars) |
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199 | in languages (such as Chill) that make a distinction. */ |
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200 | /* Array types in C or Pascal */ |
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201 | DEFTREECODE (ARRAY_TYPE, "array_type", "t", 0) |
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202 | |
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203 | /* Types of sets for Pascal. Special fields are the same as |
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204 | in an array type. The target type is always a boolean type. |
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205 | Used for both bitstrings and powersets in Chill; |
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206 | TYPE_STRING_FLAG indicates a bitstring. */ |
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207 | DEFTREECODE (SET_TYPE, "set_type", "t", 0) |
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208 | |
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209 | /* Struct in C, or record in Pascal. */ |
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210 | /* Special fields: |
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211 | TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct, |
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212 | and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables, |
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213 | types and enumerators. |
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214 | A few may need to be added for Pascal. */ |
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215 | /* See the comment above, before ENUMERAL_TYPE, for how |
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216 | forward references to struct tags are handled in C. */ |
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217 | DEFTREECODE (RECORD_TYPE, "record_type", "t", 0) |
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218 | |
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219 | /* Union in C. Like a struct, except that the offsets of the fields |
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220 | will all be zero. */ |
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221 | /* See the comment above, before ENUMERAL_TYPE, for how |
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222 | forward references to union tags are handled in C. */ |
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223 | DEFTREECODE (UNION_TYPE, "union_type", "t", 0) /* C union type */ |
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224 | |
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225 | /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER |
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226 | in each FIELD_DECL determine what the union contains. The first |
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227 | field whose DECL_QUALIFIER expression is true is deemed to occupy |
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228 | the union. */ |
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229 | DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", "t", 0) |
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230 | |
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231 | /* Type of functions. Special fields: |
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232 | TREE_TYPE type of value returned. |
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233 | TYPE_ARG_TYPES list of types of arguments expected. |
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234 | this list is made of TREE_LIST nodes. |
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235 | Types of "Procedures" in languages where they are different from functions |
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236 | have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */ |
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237 | DEFTREECODE (FUNCTION_TYPE, "function_type", "t", 0) |
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238 | |
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239 | /* This is a language-specific kind of type. |
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240 | Its meaning is defined by the language front end. |
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241 | layout_type does not know how to lay this out, |
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242 | so the front-end must do so manually. */ |
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243 | DEFTREECODE (LANG_TYPE, "lang_type", "t", 0) |
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244 | |
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245 | /* Expressions */ |
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246 | |
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247 | /* First, the constants. */ |
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248 | |
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249 | /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, |
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250 | 32 bits each, giving us a 64 bit constant capability. |
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251 | Note: constants of type char in Pascal are INTEGER_CST, |
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252 | and so are pointer constants such as nil in Pascal or NULL in C. |
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253 | `(int *) 1' in C also results in an INTEGER_CST. */ |
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254 | DEFTREECODE (INTEGER_CST, "integer_cst", "c", 2) |
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255 | |
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256 | /* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */ |
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257 | DEFTREECODE (REAL_CST, "real_cst", "c", 3) |
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258 | |
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259 | /* Contents are in TREE_REALPART and TREE_IMAGPART fields, |
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260 | whose contents are other constant nodes. |
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261 | Also there is TREE_CST_RTL. */ |
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262 | DEFTREECODE (COMPLEX_CST, "complex_cst", "c", 3) |
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263 | |
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264 | /* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields. |
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265 | Also there is TREE_CST_RTL. */ |
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266 | DEFTREECODE (STRING_CST, "string_cst", "c", 3) |
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267 | |
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268 | /* Declarations. All references to names are represented as ..._DECL nodes. |
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269 | The decls in one binding context are chained through the TREE_CHAIN field. |
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270 | Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE. |
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271 | (Some decls, most often labels, may have zero as the DECL_NAME). |
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272 | DECL_CONTEXT points to the node representing the context in which |
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273 | this declaration has its scope. For FIELD_DECLs, this is the |
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274 | RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE node that the field |
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275 | is a member of. For VAR_DECL, PARM_DECL, FUNCTION_DECL, LABEL_DECL, |
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276 | and CONST_DECL nodes, this points to either the FUNCTION_DECL for the |
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277 | containing function, the RECORD_TYPE or UNION_TYPE for the containing |
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278 | type, or NULL_TREE if the given decl has "file scope". |
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279 | DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract) |
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280 | ..._DECL node of which this decl is an (inlined or template expanded) |
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281 | instance. |
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282 | The TREE_TYPE field holds the data type of the object, when relevant. |
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283 | LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field |
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284 | contents are the type whose name is being declared. |
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285 | The DECL_ALIGN, DECL_SIZE, |
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286 | and DECL_MODE fields exist in decl nodes just as in type nodes. |
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287 | They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes. |
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288 | |
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289 | DECL_OFFSET holds an integer number of bits offset for the location. |
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290 | DECL_VOFFSET holds an expression for a variable offset; it is |
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291 | to be multiplied by DECL_VOFFSET_UNIT (an integer). |
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292 | These fields are relevant only in FIELD_DECLs and PARM_DECLs. |
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293 | |
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294 | DECL_INITIAL holds the value to initialize a variable to, |
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295 | or the value of a constant. For a function, it holds the body |
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296 | (a node of type BLOCK representing the function's binding contour |
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297 | and whose body contains the function's statements.) For a LABEL_DECL |
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298 | in C, it is a flag, nonzero if the label's definition has been seen. |
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299 | |
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300 | PARM_DECLs use a special field: |
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301 | DECL_ARG_TYPE is the type in which the argument is actually |
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302 | passed, which may be different from its type within the function. |
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303 | |
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304 | FUNCTION_DECLs use four special fields: |
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305 | DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. |
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306 | DECL_RESULT holds a RESULT_DECL node for the value of a function, |
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307 | or it is 0 for a function that returns no value. |
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308 | (C functions returning void have zero here.) |
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309 | DECL_RESULT_TYPE holds the type in which the result is actually |
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310 | returned. This is usually the same as the type of DECL_RESULT, |
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311 | but (1) it may be a wider integer type and |
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312 | (2) it remains valid, for the sake of inlining, even after the |
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313 | function's compilation is done. |
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314 | DECL_FUNCTION_CODE is a code number that is nonzero for |
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315 | built-in functions. Its value is an enum built_in_function |
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316 | that says which built-in function it is. |
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317 | |
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318 | DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE |
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319 | holds a line number. In some cases these can be the location of |
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320 | a reference, if no definition has been seen. |
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321 | |
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322 | DECL_ABSTRACT is non-zero if the decl represents an abstract instance |
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323 | of a decl (i.e. one which is nested within an abstract instance of a |
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324 | inline function. */ |
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325 | |
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326 | DEFTREECODE (FUNCTION_DECL, "function_decl", "d", 0) |
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327 | DEFTREECODE (LABEL_DECL, "label_decl", "d", 0) |
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328 | DEFTREECODE (CONST_DECL, "const_decl", "d", 0) |
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329 | DEFTREECODE (TYPE_DECL, "type_decl", "d", 0) |
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330 | DEFTREECODE (VAR_DECL, "var_decl", "d", 0) |
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331 | DEFTREECODE (PARM_DECL, "parm_decl", "d", 0) |
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332 | DEFTREECODE (RESULT_DECL, "result_decl", "d", 0) |
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333 | DEFTREECODE (FIELD_DECL, "field_decl", "d", 0) |
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334 | |
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335 | /* References to storage. */ |
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336 | |
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337 | /* Value is structure or union component. |
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338 | Operand 0 is the structure or union (an expression); |
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339 | operand 1 is the field (a node of type FIELD_DECL). */ |
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340 | DEFTREECODE (COMPONENT_REF, "component_ref", "r", 2) |
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341 | |
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342 | /* Reference to a group of bits within an object. Similar to COMPONENT_REF |
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343 | except the position is given explicitly rather than via a FIELD_DECL. |
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344 | Operand 0 is the structure or union expression; |
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345 | operand 1 is a tree giving the number of bits being referenced; |
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346 | operand 2 is a tree giving the position of the first referenced bit. |
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347 | The field can be either a signed or unsigned field; |
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348 | TREE_UNSIGNED says which. */ |
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349 | DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", "r", 3) |
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350 | |
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351 | /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ |
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352 | DEFTREECODE (INDIRECT_REF, "indirect_ref", "r", 1) |
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353 | |
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354 | /* Pascal `^` on a file. One operand, an expression for the file. */ |
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355 | DEFTREECODE (BUFFER_REF, "buffer_ref", "r", 1) |
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356 | |
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357 | /* Array indexing in languages other than C. |
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358 | Operand 0 is the array; operand 1 is a list of indices |
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359 | stored as a chain of TREE_LIST nodes. */ |
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360 | DEFTREECODE (ARRAY_REF, "array_ref", "r", 2) |
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361 | |
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362 | /* Constructor: return an aggregate value made from specified components. |
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363 | In C, this is used only for structure and array initializers. |
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364 | Also used for SET_TYPE in Chill (and potentially Pascal). |
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365 | The first "operand" is really a pointer to the RTL, |
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366 | for constant constructors only. |
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367 | The second operand is a list of component values |
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368 | made out of a chain of TREE_LIST nodes. |
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369 | |
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370 | For ARRAY_TYPE: |
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371 | The TREE_PURPOSE of each node is the corresponding index. |
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372 | If the TREE_PURPOSE is a RANGE_EXPR, it is a short-hand for many nodes, |
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373 | one for each index in the range. (If the corresponding TREE_VALUE |
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374 | has side-effects, they are evaluated once for each element. Wrap the |
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375 | value in a SAVE_EXPR if you want to evaluate side effects only once.) |
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376 | |
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377 | For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: |
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378 | The TREE_PURPOSE of each node is a FIELD_DECL. |
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379 | |
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380 | For SET_TYPE: |
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381 | The TREE_VALUE specifies a value (index) in the set that is true. |
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382 | If TREE_PURPOSE is non-NULL, it specifies the lower limit of a |
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383 | range of true values. Elements not listed are false (not in the set). */ |
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384 | DEFTREECODE (CONSTRUCTOR, "constructor", "e", 2) |
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385 | |
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386 | /* The expression types are mostly straightforward, with the fourth argument |
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387 | of DEFTREECODE saying how many operands there are. |
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388 | Unless otherwise specified, the operands are expressions and the |
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389 | types of all the operands and the expression must all be the same. */ |
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390 | |
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391 | /* Contains two expressions to compute, one followed by the other. |
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392 | the first value is ignored. The second one's value is used. The |
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393 | type of the first expression need not agree with the other types. */ |
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394 | DEFTREECODE (COMPOUND_EXPR, "compound_expr", "e", 2) |
---|
395 | |
---|
396 | /* Assignment expression. Operand 0 is the what to set; 1, the new value. */ |
---|
397 | DEFTREECODE (MODIFY_EXPR, "modify_expr", "e", 2) |
---|
398 | |
---|
399 | /* Initialization expression. Operand 0 is the variable to initialize; |
---|
400 | Operand 1 is the initializer. */ |
---|
401 | DEFTREECODE (INIT_EXPR, "init_expr", "e", 2) |
---|
402 | |
---|
403 | /* For TARGET_EXPR, operand 0 is the target of an initialization, |
---|
404 | operand 1 is the initializer for the target, |
---|
405 | and operand 2 is the cleanup for this node, if any. |
---|
406 | and operand 3 is the saved initializer after this node has been |
---|
407 | expanded once, this is so we can re-expand the tree later. */ |
---|
408 | DEFTREECODE (TARGET_EXPR, "target_expr", "e", 4) |
---|
409 | |
---|
410 | /* Conditional expression ( ... ? ... : ... in C). |
---|
411 | Operand 0 is the condition. |
---|
412 | Operand 1 is the then-value. |
---|
413 | Operand 2 is the else-value. |
---|
414 | Operand 0 may be of any types, but the types of operands 1 and 2 |
---|
415 | must be the same and the same as the the of this expression. */ |
---|
416 | DEFTREECODE (COND_EXPR, "cond_expr", "e", 3) |
---|
417 | |
---|
418 | /* Declare local variables, including making RTL and allocating space. |
---|
419 | Operand 0 is a chain of VAR_DECL nodes for the variables. |
---|
420 | Operand 1 is the body, the expression to be computed using |
---|
421 | the variables. The value of operand 1 becomes that of the BIND_EXPR. |
---|
422 | Operand 2 is the BLOCK that corresponds to these bindings |
---|
423 | for debugging purposes. If this BIND_EXPR is actually expanded, |
---|
424 | that sets the TREE_USED flag in the BLOCK. |
---|
425 | |
---|
426 | The BIND_EXPR is not responsible for informing parsers |
---|
427 | about these variables. If the body is coming from the input file, |
---|
428 | then the code that creates the BIND_EXPR is also responsible for |
---|
429 | informing the parser of the variables. |
---|
430 | |
---|
431 | If the BIND_EXPR is ever expanded, its TREE_USED flag is set. |
---|
432 | This tells the code for debugging symbol tables not to ignore the BIND_EXPR. |
---|
433 | If the BIND_EXPR should be output for debugging but will not be expanded, |
---|
434 | set the TREE_USED flag by hand. |
---|
435 | |
---|
436 | In order for the BIND_EXPR to be known at all, the code that creates it |
---|
437 | must also install it as a subblock in the tree of BLOCK |
---|
438 | nodes for the function. */ |
---|
439 | DEFTREECODE (BIND_EXPR, "bind_expr", "e", 3) |
---|
440 | |
---|
441 | /* Function call. Operand 0 is the function. |
---|
442 | Operand 1 is the argument list, a list of expressions |
---|
443 | made out of a chain of TREE_LIST nodes. |
---|
444 | There is no operand 2. That slot is used for the |
---|
445 | CALL_EXPR_RTL macro (see preexpand_calls). */ |
---|
446 | DEFTREECODE (CALL_EXPR, "call_expr", "e", 3) |
---|
447 | |
---|
448 | /* Call a method. Operand 0 is the method, whose type is a METHOD_TYPE. |
---|
449 | Operand 1 is the expression for "self". |
---|
450 | Operand 2 is the list of explicit arguments. */ |
---|
451 | DEFTREECODE (METHOD_CALL_EXPR, "method_call_expr", "e", 4) |
---|
452 | |
---|
453 | /* Specify a value to compute along with its corresponding cleanup. |
---|
454 | Operand 0 argument is an expression whose value needs a cleanup. |
---|
455 | Operand 1 is an RTL_EXPR which will eventually represent that value. |
---|
456 | Operand 2 is the cleanup expression for the object. |
---|
457 | The RTL_EXPR is used in this expression, which is how the expression |
---|
458 | manages to act on the proper value. |
---|
459 | The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, if |
---|
460 | it exists, otherwise it is the responsibility of the caller to manually |
---|
461 | call expand_start_target_temps/expand_end_target_temps, as needed. |
---|
462 | |
---|
463 | This differs from TRY_CATCH_EXPR in that operand 2 is always |
---|
464 | evaluated when an exception isn't thrown when cleanups are run. */ |
---|
465 | DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", "e", 3) |
---|
466 | |
---|
467 | /* Specify a cleanup point. |
---|
468 | Operand 0 is an expression that may have cleanups. If it does, those |
---|
469 | cleanups are executed after the expression is expanded. |
---|
470 | |
---|
471 | Note that if the expression is a reference to storage, it is forced out |
---|
472 | of memory before the cleanups are run. This is necessary to handle |
---|
473 | cases where the cleanups modify the storage referenced; in the |
---|
474 | expression 't.i', if 't' is a struct with an integer member 'i' and a |
---|
475 | cleanup which modifies 'i', the value of the expression depends on |
---|
476 | whether the cleanup is run before or after 't.i' is evaluated. When |
---|
477 | expand_expr is run on 't.i', it returns a MEM. This is not good enough; |
---|
478 | the value of 't.i' must be forced out of memory. |
---|
479 | |
---|
480 | As a consequence, the operand of a CLEANUP_POINT_EXPR must not have |
---|
481 | BLKmode, because it will not be forced out of memory. */ |
---|
482 | DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", "e", 1) |
---|
483 | |
---|
484 | /* The following two codes are used in languages that have types where |
---|
485 | the position and/or sizes of fields vary from object to object of the |
---|
486 | same type, i.e., where some other field in the object contains a value |
---|
487 | that is used in the computation of another field's offset or size. |
---|
488 | |
---|
489 | For example, a record type with a discriminant in Ada is such a type. |
---|
490 | This mechanism is also used to create "fat pointers" for unconstrained |
---|
491 | array types in Ada; the fat pointer is a structure one of whose fields is |
---|
492 | a pointer to the actual array type and the other field is a pointer to a |
---|
493 | template, which is a structure containing the bounds of the array. The |
---|
494 | bounds in the type pointed to by the first field in the fat pointer refer |
---|
495 | to the values in the template. |
---|
496 | |
---|
497 | These "self-references" are doing using a PLACEHOLDER_EXPR. This is a |
---|
498 | node that will later be replaced with the object being referenced. Its type |
---|
499 | is that of the object and selects which object to use from a chain of |
---|
500 | references (see below). |
---|
501 | |
---|
502 | When we wish to evaluate a size or offset, we check it is contains a |
---|
503 | placeholder. If it does, we construct a WITH_RECORD_EXPR that contains |
---|
504 | both the expression we wish to evaluate and an expression within which the |
---|
505 | object may be found. The latter expression is the object itself in |
---|
506 | the simple case of an Ada record with discriminant, but it can be the |
---|
507 | array in the case of an unconstrained array. |
---|
508 | |
---|
509 | In the latter case, we need the fat pointer, because the bounds of the |
---|
510 | array can only be accessed from it. However, we rely here on the fact that |
---|
511 | the expression for the array contains the dereference of the fat pointer |
---|
512 | that obtained the array pointer. |
---|
513 | |
---|
514 | Accordingly, when looking for the object to substitute in place of |
---|
515 | a PLACEHOLDER_EXPR, we look down the first operand of the expression |
---|
516 | passed as the second operand to WITH_RECORD_EXPR until we find something |
---|
517 | of the desired type or reach a constant. */ |
---|
518 | |
---|
519 | /* Denotes a record to later be supplied with a WITH_RECORD_EXPR when |
---|
520 | evaluating this expression. The type of this expression is used to |
---|
521 | find the record to replace it. */ |
---|
522 | DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", "x", 0) |
---|
523 | |
---|
524 | /* Provide an expression that references a record to be used in place |
---|
525 | of a PLACEHOLDER_EXPR. The record to be used is the record within |
---|
526 | operand 1 that has the same type as the PLACEHOLDER_EXPR in |
---|
527 | operand 0. */ |
---|
528 | DEFTREECODE (WITH_RECORD_EXPR, "with_record_expr", "e", 2) |
---|
529 | |
---|
530 | /* Simple arithmetic. */ |
---|
531 | DEFTREECODE (PLUS_EXPR, "plus_expr", "2", 2) |
---|
532 | DEFTREECODE (MINUS_EXPR, "minus_expr", "2", 2) |
---|
533 | DEFTREECODE (MULT_EXPR, "mult_expr", "2", 2) |
---|
534 | |
---|
535 | /* Division for integer result that rounds the quotient toward zero. */ |
---|
536 | DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", "2", 2) |
---|
537 | |
---|
538 | /* Division for integer result that rounds the quotient toward infinity. */ |
---|
539 | DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", "2", 2) |
---|
540 | |
---|
541 | /* Division for integer result that rounds toward minus infinity. */ |
---|
542 | DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", "2", 2) |
---|
543 | |
---|
544 | /* Division for integer result that rounds toward nearest integer. */ |
---|
545 | DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", "2", 2) |
---|
546 | |
---|
547 | /* Four kinds of remainder that go with the four kinds of division. */ |
---|
548 | DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", "2", 2) |
---|
549 | DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", "2", 2) |
---|
550 | DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", "2", 2) |
---|
551 | DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", "2", 2) |
---|
552 | |
---|
553 | /* Division for real result. */ |
---|
554 | DEFTREECODE (RDIV_EXPR, "rdiv_expr", "2", 2) |
---|
555 | |
---|
556 | /* Division which is not supposed to need rounding. |
---|
557 | Used for pointer subtraction in C. */ |
---|
558 | DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", "2", 2) |
---|
559 | |
---|
560 | /* Conversion of real to fixed point: four ways to round, |
---|
561 | like the four ways to divide. |
---|
562 | CONVERT_EXPR can also be used to convert a real to an integer, |
---|
563 | and that is what is used in languages that do not have ways of |
---|
564 | specifying which of these is wanted. Maybe these are not needed. */ |
---|
565 | DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", "1", 1) |
---|
566 | DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", "1", 1) |
---|
567 | DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", "1", 1) |
---|
568 | DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", "1", 1) |
---|
569 | |
---|
570 | /* Conversion of an integer to a real. */ |
---|
571 | DEFTREECODE (FLOAT_EXPR, "float_expr", "1", 1) |
---|
572 | |
---|
573 | /* Exponentiation. Operands may have any types; |
---|
574 | constraints on value type are not known yet. */ |
---|
575 | DEFTREECODE (EXPON_EXPR, "expon_expr", "2", 2) |
---|
576 | |
---|
577 | /* Unary negation. */ |
---|
578 | DEFTREECODE (NEGATE_EXPR, "negate_expr", "1", 1) |
---|
579 | |
---|
580 | DEFTREECODE (MIN_EXPR, "min_expr", "2", 2) |
---|
581 | DEFTREECODE (MAX_EXPR, "max_expr", "2", 2) |
---|
582 | DEFTREECODE (ABS_EXPR, "abs_expr", "1", 1) |
---|
583 | DEFTREECODE (FFS_EXPR, "ffs_expr", "1", 1) |
---|
584 | |
---|
585 | /* Shift operations for shift and rotate. |
---|
586 | Shift is supposed to mean logical shift if done on an |
---|
587 | unsigned type, arithmetic shift on a signed type. |
---|
588 | The second operand is the number of bits to |
---|
589 | shift by; it need not be the same type as the first operand and result. */ |
---|
590 | DEFTREECODE (LSHIFT_EXPR, "lshift_expr", "2", 2) |
---|
591 | DEFTREECODE (RSHIFT_EXPR, "rshift_expr", "2", 2) |
---|
592 | DEFTREECODE (LROTATE_EXPR, "lrotate_expr", "2", 2) |
---|
593 | DEFTREECODE (RROTATE_EXPR, "rrotate_expr", "2", 2) |
---|
594 | |
---|
595 | /* Bitwise operations. Operands have same mode as result. */ |
---|
596 | DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", "2", 2) |
---|
597 | DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", "2", 2) |
---|
598 | DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", "2", 2) |
---|
599 | DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", "2", 2) |
---|
600 | DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", "1", 1) |
---|
601 | |
---|
602 | /* Combination of boolean values or of integers considered only |
---|
603 | as zero or nonzero. ANDIF and ORIF allow the second operand |
---|
604 | not to be computed if the value of the expression is determined |
---|
605 | from the first operand. AND, OR, and XOR always compute the second |
---|
606 | operand whether its value is needed or not (for side effects). */ |
---|
607 | DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", "e", 2) |
---|
608 | DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", "e", 2) |
---|
609 | DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", "e", 2) |
---|
610 | DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", "e", 2) |
---|
611 | DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", "e", 2) |
---|
612 | DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", "e", 1) |
---|
613 | |
---|
614 | /* Relational operators. |
---|
615 | `EQ_EXPR' and `NE_EXPR' are allowed for any types. |
---|
616 | The others are allowed only for integer (or pointer or enumeral) |
---|
617 | or real types. |
---|
618 | In all cases the operands will have the same type, |
---|
619 | and the value is always the type used by the language for booleans. */ |
---|
620 | DEFTREECODE (LT_EXPR, "lt_expr", "<", 2) |
---|
621 | DEFTREECODE (LE_EXPR, "le_expr", "<", 2) |
---|
622 | DEFTREECODE (GT_EXPR, "gt_expr", "<", 2) |
---|
623 | DEFTREECODE (GE_EXPR, "ge_expr", "<", 2) |
---|
624 | DEFTREECODE (EQ_EXPR, "eq_expr", "<", 2) |
---|
625 | DEFTREECODE (NE_EXPR, "ne_expr", "<", 2) |
---|
626 | |
---|
627 | /* Operations for Pascal sets. Not used now. */ |
---|
628 | DEFTREECODE (IN_EXPR, "in_expr", "2", 2) |
---|
629 | DEFTREECODE (SET_LE_EXPR, "set_le_expr", "<", 2) |
---|
630 | DEFTREECODE (CARD_EXPR, "card_expr", "1", 1) |
---|
631 | DEFTREECODE (RANGE_EXPR, "range_expr", "2", 2) |
---|
632 | |
---|
633 | /* Represents a conversion of type of a value. |
---|
634 | All conversions, including implicit ones, must be |
---|
635 | represented by CONVERT_EXPR or NOP_EXPR nodes. */ |
---|
636 | DEFTREECODE (CONVERT_EXPR, "convert_expr", "1", 1) |
---|
637 | |
---|
638 | /* Represents a conversion expected to require no code to be generated. */ |
---|
639 | DEFTREECODE (NOP_EXPR, "nop_expr", "1", 1) |
---|
640 | |
---|
641 | /* Value is same as argument, but guaranteed not an lvalue. */ |
---|
642 | DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", "1", 1) |
---|
643 | |
---|
644 | /* Represents something we computed once and will use multiple times. |
---|
645 | First operand is that expression. Second is the function decl |
---|
646 | in which the SAVE_EXPR was created. The third operand is the RTL, |
---|
647 | nonzero only after the expression has been computed. */ |
---|
648 | DEFTREECODE (SAVE_EXPR, "save_expr", "e", 3) |
---|
649 | |
---|
650 | /* For a UNSAVE_EXPR, operand 0 is the value to unsave. By unsave, we |
---|
651 | mean that all _EXPRs such as TARGET_EXPRs, SAVE_EXPRs, |
---|
652 | CALL_EXPRs and RTL_EXPRs, that are protected |
---|
653 | from being evaluated more than once should be reset so that a new |
---|
654 | expand_expr call of this expr will cause those to be re-evaluated. |
---|
655 | This is useful when we want to reuse a tree in different places, |
---|
656 | but where we must re-expand. */ |
---|
657 | DEFTREECODE (UNSAVE_EXPR, "unsave_expr", "e", 1) |
---|
658 | |
---|
659 | /* Represents something whose RTL has already been expanded |
---|
660 | as a sequence which should be emitted when this expression is expanded. |
---|
661 | The first operand is the RTL to emit. It is the first of a chain of insns. |
---|
662 | The second is the RTL expression for the result. */ |
---|
663 | DEFTREECODE (RTL_EXPR, "rtl_expr", "e", 2) |
---|
664 | |
---|
665 | /* & in C. Value is the address at which the operand's value resides. |
---|
666 | Operand may have any mode. Result mode is Pmode. */ |
---|
667 | DEFTREECODE (ADDR_EXPR, "addr_expr", "e", 1) |
---|
668 | |
---|
669 | /* Non-lvalue reference or pointer to an object. */ |
---|
670 | DEFTREECODE (REFERENCE_EXPR, "reference_expr", "e", 1) |
---|
671 | |
---|
672 | /* Operand is a function constant; result is a function variable value |
---|
673 | of typeEPmode. Used only for languages that need static chains. */ |
---|
674 | DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", "e", 1) |
---|
675 | |
---|
676 | /* Given two real or integer operands of the same type, |
---|
677 | returns a complex value of the corresponding complex type. */ |
---|
678 | DEFTREECODE (COMPLEX_EXPR, "complex_expr", "2", 2) |
---|
679 | |
---|
680 | /* Complex conjugate of operand. Used only on complex types. */ |
---|
681 | DEFTREECODE (CONJ_EXPR, "conj_expr", "1", 1) |
---|
682 | |
---|
683 | /* Used only on an operand of complex type, these return |
---|
684 | a value of the corresponding component type. */ |
---|
685 | DEFTREECODE (REALPART_EXPR, "realpart_expr", "1", 1) |
---|
686 | DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", "1", 1) |
---|
687 | |
---|
688 | /* Nodes for ++ and -- in C. |
---|
689 | The second arg is how much to increment or decrement by. |
---|
690 | For a pointer, it would be the size of the object pointed to. */ |
---|
691 | DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", "e", 2) |
---|
692 | DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", "e", 2) |
---|
693 | DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", "e", 2) |
---|
694 | DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", "e", 2) |
---|
695 | |
---|
696 | /* Evaluate operand 1. If and only if an exception is thrown during |
---|
697 | the evaluation of operand 1, evaluate operand 2. |
---|
698 | |
---|
699 | This differs from WITH_CLEANUP_EXPR, in that operand 2 is never |
---|
700 | evaluated unless an exception is throw. */ |
---|
701 | DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", "e", 2) |
---|
702 | |
---|
703 | /* Pop the top element off the dynamic handler chain. Used in |
---|
704 | conjunction with setjmp/longjmp based exception handling, see |
---|
705 | except.c for more details. This is meant to be used only by the |
---|
706 | exception handling backend, expand_dhc_cleanup specifically. */ |
---|
707 | DEFTREECODE (POPDHC_EXPR, "popdhc_expr", "s", 0) |
---|
708 | |
---|
709 | /* Pop the top element off the dynamic cleanup chain. Used in |
---|
710 | conjunction with the exception handling. This is meant to be used |
---|
711 | only by the exception handling backend. */ |
---|
712 | DEFTREECODE (POPDCC_EXPR, "popdcc_expr", "s", 0) |
---|
713 | |
---|
714 | /* These types of expressions have no useful value, |
---|
715 | and always have side effects. */ |
---|
716 | |
---|
717 | /* A label definition, encapsulated as a statement. |
---|
718 | Operand 0 is the LABEL_DECL node for the label that appears here. |
---|
719 | The type should be void and the value should be ignored. */ |
---|
720 | DEFTREECODE (LABEL_EXPR, "label_expr", "s", 1) |
---|
721 | |
---|
722 | /* GOTO. Operand 0 is a LABEL_DECL node. |
---|
723 | The type should be void and the value should be ignored. */ |
---|
724 | DEFTREECODE (GOTO_EXPR, "goto_expr", "s", 1) |
---|
725 | |
---|
726 | /* RETURN. Evaluates operand 0, then returns from the current function. |
---|
727 | Presumably that operand is an assignment that stores into the |
---|
728 | RESULT_DECL that hold the value to be returned. |
---|
729 | The operand may be null. |
---|
730 | The type should be void and the value should be ignored. */ |
---|
731 | DEFTREECODE (RETURN_EXPR, "return_expr", "s", 1) |
---|
732 | |
---|
733 | /* Exit the inner most loop conditionally. Operand 0 is the condition. |
---|
734 | The type should be void and the value should be ignored. */ |
---|
735 | DEFTREECODE (EXIT_EXPR, "exit_expr", "s", 1) |
---|
736 | |
---|
737 | /* A loop. Operand 0 is the body of the loop. |
---|
738 | It must contain an EXIT_EXPR or is an infinite loop. |
---|
739 | The type should be void and the value should be ignored. */ |
---|
740 | DEFTREECODE (LOOP_EXPR, "loop_expr", "s", 1) |
---|
741 | |
---|
742 | /* |
---|
743 | Local variables: |
---|
744 | mode:c |
---|
745 | End: |
---|
746 | */ |
---|