+/* Definitions for expressions stored in reversed prefix form, for GDB.
+ Copyright (C) 1986, 1989 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+GDB is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 1, or (at your option)
+any later version.
+
+GDB is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GDB; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* Definitions for saved C expressions. */
+
+/* An expression is represented as a vector of union exp_element's.
+ Each exp_element is an opcode, except that some opcodes cause
+ the following exp_element to be treated as a long or double constant
+ or as a variable. The opcodes are obeyed, using a stack for temporaries.
+ The value is left on the temporary stack at the end. */
+
+/* When it is necessary to include a string,
+ it can occupy as many exp_elements as it needs.
+ We find the length of the string using strlen,
+ divide to find out how many exp_elements are used up,
+ and skip that many. Strings, like numbers, are indicated
+ by the preceding opcode. */
+
+enum exp_opcode
+{
+/* BINOP_... operate on two values computed by following subexpressions,
+ replacing them by one result value. They take no immediate arguments. */
+ BINOP_ADD, /* + */
+ BINOP_SUB, /* - */
+ BINOP_MUL, /* * */
+ BINOP_DIV, /* / */
+ BINOP_REM, /* % */
+ BINOP_LSH, /* << */
+ BINOP_RSH, /* >> */
+ BINOP_AND, /* && */
+ BINOP_OR, /* || */
+ BINOP_LOGAND, /* & */
+ BINOP_LOGIOR, /* | */
+ BINOP_LOGXOR, /* ^ */
+ BINOP_EQUAL, /* == */
+ BINOP_NOTEQUAL, /* != */
+ BINOP_LESS, /* < */
+ BINOP_GTR, /* > */
+ BINOP_LEQ, /* <= */
+ BINOP_GEQ, /* >= */
+ BINOP_REPEAT, /* @ */
+ BINOP_ASSIGN, /* = */
+ BINOP_COMMA, /* , */
+ BINOP_SUBSCRIPT, /* x[y] */
+ BINOP_EXP, /* Exponentiation */
+
+/* C++. */
+ BINOP_MIN, /* <? */
+ BINOP_MAX, /* >? */
+ BINOP_SCOPE, /* :: */
+
+ /* STRUCTOP_MEMBER is used for pointer-to-member constructs.
+ X . * Y translates into X STRUCTOP_MEMBER Y. */
+ STRUCTOP_MEMBER,
+ /* STRUCTOP_MPTR is used for pointer-to-member constructs
+ when X is a pointer instead of an aggregate. */
+ STRUCTOP_MPTR,
+/* end of C++. */
+
+ BINOP_END,
+
+ BINOP_ASSIGN_MODIFY, /* +=, -=, *=, and so on.
+ The following exp_element is another opcode,
+ a BINOP_, saying how to modify.
+ Then comes another BINOP_ASSIGN_MODIFY,
+ making three exp_elements in total. */
+
+/* Operates on three values computed by following subexpressions. */
+ TERNOP_COND, /* ?: */
+
+/* The OP_... series take immediate following arguments.
+ After the arguments come another OP_... (the same one)
+ so that the grouping can be recognized from the end. */
+
+/* OP_LONG is followed by a type pointer in the next exp_element
+ and the long constant value in the following exp_element.
+ Then comes another OP_LONG.
+ Thus, the operation occupies four exp_elements. */
+
+ OP_LONG,
+/* OP_DOUBLE is similar but takes a double constant instead of a long one. */
+ OP_DOUBLE,
+/* OP_VAR_VALUE takes one struct symbol * in the following exp_element,
+ followed by another OP_VAR_VALUE, making three exp_elements. */
+ OP_VAR_VALUE,
+/* OP_LAST is followed by an integer in the next exp_element.
+ The integer is zero for the last value printed,
+ or it is the absolute number of a history element.
+ With another OP_LAST at the end, this makes three exp_elements. */
+ OP_LAST,
+/* OP_REGISTER is followed by an integer in the next exp_element.
+ This is the number of a register to fetch (as an int).
+ With another OP_REGISTER at the end, this makes three exp_elements. */
+ OP_REGISTER,
+/* OP_INTERNALVAR is followed by an internalvar ptr in the next exp_element.
+ With another OP_INTERNALVAR at the end, this makes three exp_elements. */
+ OP_INTERNALVAR,
+/* OP_FUNCALL is followed by an integer in the next exp_element.
+ The integer is the number of args to the function call.
+ That many plus one values from following subexpressions
+ are used, the first one being the function.
+ The integer is followed by a repeat of OP_FUNCALL,
+ making three exp_elements. */
+ OP_FUNCALL,
+/* OP_STRING represents a string constant.
+ Its format is the same as that of a STRUCTOP, but the string
+ data is just made into a string constant when the operation
+ is executed. */
+ OP_STRING,
+
+/* UNOP_CAST is followed by a type pointer in the next exp_element.
+ With another UNOP_CAST at the end, this makes three exp_elements.
+ It casts the value of the following subexpression. */
+ UNOP_CAST,
+/* UNOP_MEMVAL is followed by a type pointer in the next exp_element
+ With another UNOP_MEMVAL at the end, this makes three exp_elements.
+ It casts the contents of the word addressed by the value of the
+ following subexpression. */
+ UNOP_MEMVAL,
+/* UNOP_... operate on one value from a following subexpression
+ and replace it with a result. They take no immediate arguments. */
+ UNOP_NEG, /* Unary - */
+ UNOP_ZEROP, /* Unary ! */
+ UNOP_LOGNOT, /* Unary ~ */
+ UNOP_IND, /* Unary * */
+ UNOP_ADDR, /* Unary & */
+ UNOP_PREINCREMENT, /* ++ before an expression */
+ UNOP_POSTINCREMENT, /* ++ after an expression */
+ UNOP_PREDECREMENT, /* -- before an expression */
+ UNOP_POSTDECREMENT, /* -- after an expression */
+ UNOP_SIZEOF, /* Unary sizeof (followed by expression) */
+
+/* STRUCTOP_... operate on a value from a following subexpression
+ by extracting a structure component specified by a string
+ that appears in the following exp_elements (as many as needed).
+ STRUCTOP_STRUCT is used for "." and STRUCTOP_PTR for "->".
+ They differ only in the error message given in case the value is
+ not suitable or the structure component specified is not found.
+
+ The length of the string follows in the next exp_element,
+ (after the string), followed by another STRUCTOP_... code. */
+ STRUCTOP_STRUCT,
+ STRUCTOP_PTR,
+
+/* C++ */
+ /* OP_THIS is just a placeholder for the class instance variable.
+ It just comes in a tight (OP_THIS, OP_THIS) pair. */
+ OP_THIS,
+
+ /* OP_SCOPE surrounds a type name and a field name. The type
+ name is encoded as one element, but the field name stays as
+ a string, which, of course, is variable length. */
+ OP_SCOPE,
+
+};
+
+union exp_element
+{
+ enum exp_opcode opcode;
+ struct symbol *symbol;
+ LONGEST longconst;
+ double doubleconst;
+ char string;
+ struct type *type;
+ struct internalvar *internalvar;
+};
+
+struct expression
+{
+ int nelts;
+ union exp_element elts[1];
+};
+
+struct expression *parse_c_expression ();
+struct expression *parse_c_1 ();
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