X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=gdb%2Fexpression.h;h=3ba68a2db93eaec6a4014551acf508a6a628acab;hb=1d2eeb660f0885807320792ee18c033b34522225;hp=82b9367dd60b00ffadb595f3b337e01266db131b;hpb=072bba3b0f3e2ee8d2cfc94e256d0f0ebc627afc;p=binutils-gdb.git diff --git a/gdb/expression.h b/gdb/expression.h index 82b9367dd60..3ba68a2db93 100644 --- a/gdb/expression.h +++ b/gdb/expression.h @@ -1,7 +1,6 @@ /* Definitions for expressions stored in reversed prefix form, for GDB. - Copyright (C) 1986, 1989, 1992, 1994, 2000, 2003, 2005, 2007, 2008, 2009 - Free Software Foundation, Inc. + Copyright (C) 1986-2022 Free Software Foundation, Inc. This file is part of GDB. @@ -21,428 +20,290 @@ #if !defined (EXPRESSION_H) #define EXPRESSION_H 1 +#include "gdbtypes.h" -#include "symtab.h" /* Needed for "struct block" type. */ -#include "doublest.h" /* Needed for DOUBLEST. */ +/* While parsing expressions we need to track the innermost lexical block + that we encounter. In some situations we need to track the innermost + block just for symbols, and in other situations we want to track the + innermost block for symbols and registers. These flags are used by the + innermost block tracker to control which blocks we consider for the + innermost block. These flags can be combined together as needed. */ +enum innermost_block_tracker_type +{ + /* Track the innermost block for symbols within an expression. */ + INNERMOST_BLOCK_FOR_SYMBOLS = (1 << 0), -/* Definitions for saved C expressions. */ + /* Track the innermost block for registers within an expression. */ + INNERMOST_BLOCK_FOR_REGISTERS = (1 << 1) +}; +DEF_ENUM_FLAGS_TYPE (enum innermost_block_tracker_type, + innermost_block_tracker_types); -/* 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. */ +enum exp_opcode : uint8_t + { +#define OP(name) name , -/* 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. */ +#include "std-operator.def" -enum exp_opcode - { - /* Used when it's necessary to pass an opcode which will be ignored, - or to catch uninitialized values. */ - OP_NULL, - -/* 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_MOD, /* mod (Knuth 1.2.4) */ - BINOP_LSH, /* << */ - BINOP_RSH, /* >> */ - BINOP_LOGICAL_AND, /* && */ - BINOP_LOGICAL_OR, /* || */ - BINOP_BITWISE_AND, /* & */ - BINOP_BITWISE_IOR, /* | */ - BINOP_BITWISE_XOR, /* ^ */ - 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, /* ? */ - - /* 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, - - /* TYPE_INSTANCE is used when the user specifies a specific - type instantiation for overloaded methods/functions. - - The format is: - TYPE_INSTANCE num_types type0 ... typeN num_types TYPE_INSTANCE */ - TYPE_INSTANCE, - - /* end of C++. */ - - /* For Modula-2 integer division DIV */ - BINOP_INTDIV, - - 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. */ - - /* Modula-2 standard (binary) procedures */ - BINOP_VAL, - BINOP_INCL, - BINOP_EXCL, - - /* Concatenate two operands, such as character strings or bitstrings. - If the first operand is a integer expression, then it means concatenate - the second operand with itself that many times. */ - BINOP_CONCAT, - - /* For (the deleted) Chill and Pascal. */ - BINOP_IN, /* Returns 1 iff ARG1 IN ARG2. */ - - /* This is the "colon operator" used various places in (the - deleted) Chill. */ - BINOP_RANGE, - - /* This must be the highest BINOP_ value, for expprint.c. */ - BINOP_END, - - /* Operates on three values computed by following subexpressions. */ - TERNOP_COND, /* ?: */ - - /* A sub-string/sub-array. (the deleted) Chill syntax: - OP1(OP2:OP3). Return elements OP2 through OP3 of OP1. */ - TERNOP_SLICE, - - /* A sub-string/sub-array. (The deleted) Chill syntax: OP1(OP2 UP - OP3). Return OP3 elements of OP1, starting with element - OP2. */ - TERNOP_SLICE_COUNT, - - /* Multidimensional subscript operator, such as Modula-2 x[a,b,...]. - The dimensionality is encoded in the operator, like the number of - function arguments in OP_FUNCALL, I.E. . - The value of the first following subexpression is subscripted - by each of the next following subexpressions, one per dimension. */ - MULTI_SUBSCRIPT, - - /* 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 DOUBLEST constant instead of a long. */ - OP_DOUBLE, - - /* OP_VAR_VALUE takes one struct block * in the following element, - and one struct symbol * in the following exp_element, followed by - another OP_VAR_VALUE, making four exp_elements. If the block is - non-NULL, evaluate the symbol relative to the innermost frame - executing in that block; if the block is NULL use the selected frame. */ - 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 a string in the next exp_element. - This is the name of a register to fetch. */ - 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_OBJC_MSGCALL is followed by a string in the next exp_element and then an - integer. The string is the selector string. The integer is the number - of arguments to the message call. That many plus one values are used, - the first one being the object pointer. This is an Objective C message */ - OP_OBJC_MSGCALL, - - /* This is EXACTLY like OP_FUNCALL but is semantically different. - In F77, array subscript expressions, substring expressions - and function calls are all exactly the same syntactically. They may - only be disambiguated at runtime. Thus this operator, which - indicates that we have found something of the form ( ) */ - OP_F77_UNDETERMINED_ARGLIST, - - /* OP_COMPLEX takes a type in the following element, followed by another - OP_COMPLEX, making three exp_elements. It is followed by two double - args, and converts them into a complex number of the given type. */ - OP_COMPLEX, - - /* 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, - - /* OP_BITSTRING represents a packed bitstring constant. - Its format is the same as that of a STRUCTOP, but the bitstring - data is just made into a bitstring constant when the operation - is executed. */ - OP_BITSTRING, - - /* OP_ARRAY creates an array constant out of the following subexpressions. - It is followed by two exp_elements, the first containing an integer - that is the lower bound of the array and the second containing another - integer that is the upper bound of the array. The second integer is - followed by a repeat of OP_ARRAY, making four exp_elements total. - The bounds are used to compute the number of following subexpressions - to consume, as well as setting the bounds in the created array constant. - The type of the elements is taken from the type of the first subexp, - and they must all match. */ - OP_ARRAY, - - /* 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_MEMVAL_TLS is followed by a `struct objfile' pointer in the next - exp_element and a type pointer in the following exp_element. - With another UNOP_MEMVAL_TLS at the end, this makes four exp_elements. - It casts the contents of the word offsetted by the value of the - following subexpression from the TLS specified by `struct objfile'. */ - UNOP_MEMVAL_TLS, - - /* UNOP_... operate on one value from a following subexpression - and replace it with a result. They take no immediate arguments. */ - - UNOP_NEG, /* Unary - */ - UNOP_LOGICAL_NOT, /* Unary ! */ - UNOP_COMPLEMENT, /* 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) */ - - UNOP_PLUS, /* Unary plus */ - - UNOP_CAP, /* Modula-2 standard (unary) procedures */ - UNOP_CHR, - UNOP_ORD, - UNOP_ABS, - UNOP_FLOAT, - UNOP_HIGH, - UNOP_MAX, - UNOP_MIN, - UNOP_ODD, - UNOP_TRUNC, - - /* (The deleted) Chill builtin functions. */ - UNOP_LOWER, UNOP_UPPER, UNOP_LENGTH, UNOP_CARD, UNOP_CHMAX, UNOP_CHMIN, - - OP_BOOL, /* Modula-2 builtin BOOLEAN type */ - OP_M2_STRING, /* Modula-2 string constants */ - - /* 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 the opcode, followed by - BYTES_TO_EXP_ELEM(length) elements containing the data of the - string, followed by the length again and the opcode again. */ - - 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, - - /* Objective-C: OP_OBJC_SELF is just a placeholder for the class instance - variable. It just comes in a tight (OP_OBJC_SELF, OP_OBJC_SELF) pair. */ - OP_OBJC_SELF, - - /* Objective C: "@selector" pseudo-operator */ - OP_OBJC_SELECTOR, - - /* 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, - - /* Used to represent named structure field values in brace - initializers (or tuples as they are called in (the deleted) - Chill). - - The gcc C syntax is NAME:VALUE or .NAME=VALUE, the (the - deleted) Chill syntax is .NAME:VALUE. Multiple labels (as in - the (the deleted) Chill syntax .NAME1,.NAME2:VALUE) is - represented as if it were .NAME1:(.NAME2:VALUE) (though that is - not valid (the deleted) Chill syntax). - - The NAME is represented as for STRUCTOP_STRUCT; VALUE follows. */ - OP_LABELED, - - /* OP_TYPE is for parsing types, and used with the "ptype" command - so we can look up types that are qualified by scope, either with - the GDB "::" operator, or the Modula-2 '.' operator. */ - OP_TYPE, - - /* An un-looked-up identifier. */ - OP_NAME, - - /* An Objective C Foundation Class NSString constant */ - OP_OBJC_NSSTRING, - - /* A F90 array range operator (for "exp:exp", "exp:", ":exp" and ":"). */ - OP_F90_RANGE, - - /* OP_DECFLOAT is followed by a type pointer in the next exp_element - and a dec long constant value in the following exp_element. - Then comes another OP_DECFLOAT. */ - OP_DECFLOAT, - - /* First extension operator. Individual language modules define - extra operators in *.inc include files below always starting with - numbering at OP_EXTENDED0: - BINOP_MOGRIFY = OP_EXTENDED0, - BINOP_FROB, - ... */ - OP_EXTENDED0, - - /* Last possible extension operator. Defined to provide an - explicit and finite number of extended operators. */ - OP_EXTENDED_LAST = 0xff, - /* NOTE: Eventually, we expect to convert to an object-oriented - formulation for expression operators that does away with the - need for these extension operators, and indeed for this - entire enumeration type. Therefore, consider the OP_EXTENDED - definitions to be a temporary measure. */ - - /* Each language specific set of operators starts at OP_EXTENDED0. */ -#include "ada-operator.inc" - - /* Existing only to swallow the last comma (',') from last .inc file. */ - OP_UNUSED_LAST +#undef OP }; -union exp_element +/* Values of NOSIDE argument to eval_subexp. */ + +enum noside { - enum exp_opcode opcode; - struct symbol *symbol; - LONGEST longconst; - DOUBLEST doubleconst; - gdb_byte decfloatconst[16]; - /* Really sizeof (union exp_element) characters (or less for the last - element of a string). */ - char string; - struct type *type; - struct internalvar *internalvar; - struct block *block; - struct objfile *objfile; + EVAL_NORMAL, + EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or + call any functions. The value + returned will have the correct + type, and will have an + approximately correct lvalue + type (inaccuracy: anything that is + listed as being in a register in + the function in which it was + declared will be lval_register). + Ideally this would not even read + target memory, but currently it + does in many situations. */ }; +struct expression; +struct agent_expr; +struct axs_value; +struct type; +struct ui_file; + +namespace expr +{ + +class operation; +typedef std::unique_ptr operation_up; + +/* Base class for an operation. An operation is a single component of + an expression. */ + +class operation +{ +protected: + + operation () = default; + DISABLE_COPY_AND_ASSIGN (operation); + +public: + + virtual ~operation () = default; + + /* Evaluate this operation. */ + virtual value *evaluate (struct type *expect_type, + struct expression *exp, + enum noside noside) = 0; + + /* Evaluate this operation in a context where C-like coercion is + needed. */ + virtual value *evaluate_with_coercion (struct expression *exp, + enum noside noside) + { + return evaluate (nullptr, exp, noside); + } + + /* Evaluate this expression in the context of a cast to + EXPECT_TYPE. */ + virtual value *evaluate_for_cast (struct type *expect_type, + struct expression *exp, + enum noside noside); + + /* Evaluate this expression in the context of a sizeof + operation. */ + virtual value *evaluate_for_sizeof (struct expression *exp, + enum noside noside); + + /* Evaluate this expression in the context of an address-of + operation. Must return the address. */ + virtual value *evaluate_for_address (struct expression *exp, + enum noside noside); + + /* Evaluate a function call, with this object as the callee. + EXPECT_TYPE, EXP, and NOSIDE have the same meaning as in + 'evaluate'. ARGS holds the operations that should be evaluated + to get the arguments to the call. */ + virtual value *evaluate_funcall (struct type *expect_type, + struct expression *exp, + enum noside noside, + const std::vector &args) + { + /* Defer to the helper overload. */ + return evaluate_funcall (expect_type, exp, noside, nullptr, args); + } + + /* True if this is a constant expression. */ + virtual bool constant_p () const + { return false; } + + /* Return true if this operation uses OBJFILE (and will become + dangling when OBJFILE is unloaded), otherwise return false. + OBJFILE must not be a separate debug info file. */ + virtual bool uses_objfile (struct objfile *objfile) const + { return false; } + + /* Generate agent expression bytecodes for this operation. */ + void generate_ax (struct expression *exp, struct agent_expr *ax, + struct axs_value *value, + struct type *cast_type = nullptr); + + /* Return the opcode that is implemented by this operation. */ + virtual enum exp_opcode opcode () const = 0; + + /* Print this operation to STREAM. */ + virtual void dump (struct ui_file *stream, int depth) const = 0; + + /* Call to indicate that this is the outermost operation in the + expression. This should almost never be overridden. */ + virtual void set_outermost () { } + +protected: + + /* A helper overload that wraps evaluate_subexp_do_call. */ + value *evaluate_funcall (struct type *expect_type, + struct expression *exp, + enum noside noside, + const char *function_name, + const std::vector &args); + + /* Called by generate_ax to do the work for this particular + operation. */ + virtual void do_generate_ax (struct expression *exp, + struct agent_expr *ax, + struct axs_value *value, + struct type *cast_type) + { + error (_("Cannot translate to agent expression")); + } +}; + +/* A helper function for creating an operation_up, given a type. */ +template +operation_up +make_operation (Arg... args) +{ + return operation_up (new T (std::forward (args)...)); +} + +} + struct expression +{ + expression (const struct language_defn *lang, struct gdbarch *arch) + : language_defn (lang), + gdbarch (arch) { - const struct language_defn *language_defn; /* language it was entered in */ - struct gdbarch *gdbarch; /* architecture it was parsed in */ - int nelts; - union exp_element elts[1]; - }; + } -/* Macros for converting between number of expression elements and bytes - to store that many expression elements. */ + DISABLE_COPY_AND_ASSIGN (expression); -#define EXP_ELEM_TO_BYTES(elements) \ - ((elements) * sizeof (union exp_element)) -#define BYTES_TO_EXP_ELEM(bytes) \ - (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element)) + /* Return the opcode for the outermost sub-expression of this + expression. */ + enum exp_opcode first_opcode () const + { + return op->opcode (); + } + + /* Evaluate the expression. EXPECT_TYPE is the context type of the + expression; normally this should be nullptr. NOSIDE controls how + evaluation is performed. */ + struct value *evaluate (struct type *expect_type, enum noside noside); + + /* Language it was entered in. */ + const struct language_defn *language_defn; + /* Architecture it was parsed in. */ + struct gdbarch *gdbarch; + expr::operation_up op; +}; + +typedef std::unique_ptr expression_up; /* From parse.c */ -extern struct expression *parse_expression (char *); +class innermost_block_tracker; +extern expression_up parse_expression (const char *, + innermost_block_tracker * = nullptr, + bool void_context_p = false); -extern struct type *parse_field_expression (char *, char **); +extern expression_up parse_expression_with_language (const char *string, + enum language lang); -extern struct expression *parse_exp_1 (char **, struct block *, int); -/* For use by parsers; set if we want to parse an expression and - attempt to complete a field name. */ -extern int in_parse_field; +class completion_tracker; -/* The innermost context required by the stack and register variables - we've encountered so far. To use this, set it to NULL, then call - parse_, then look at it. */ -extern struct block *innermost_block; +/* Base class for expression completion. An instance of this + represents a completion request from the parser. */ +struct expr_completion_base +{ + /* Perform this object's completion. EXP is the expression in which + the completion occurs. TRACKER is the tracker to update with the + results. Return true if completion was possible (even if no + completions were found), false to fall back to ordinary + expression completion (i.e., symbol names). */ + virtual bool complete (struct expression *exp, + completion_tracker &tracker) = 0; -/* From eval.c */ + virtual ~expr_completion_base () = default; +}; -/* Values of NOSIDE argument to eval_subexp. */ +extern expression_up parse_expression_for_completion + (const char *, std::unique_ptr *completer); -enum noside - { - EVAL_NORMAL, - EVAL_SKIP, /* Only effect is to increment pos. */ - EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or - call any functions. The value - returned will have the correct - type, and will have an - approximately correct lvalue - type (inaccuracy: anything that is - listed as being in a register in - the function in which it was - declared will be lval_register). */ - }; +class innermost_block_tracker; +extern expression_up parse_exp_1 (const char **, CORE_ADDR pc, + const struct block *, int, + innermost_block_tracker * = nullptr); -extern struct value *evaluate_subexp_standard - (struct type *, struct expression *, int *, enum noside); +/* From eval.c */ -/* From expprint.c */ +/* Evaluate a function call. The function to be called is in CALLEE and + the arguments passed to the function are in ARGVEC. + FUNCTION_NAME is the name of the function, if known. + DEFAULT_RETURN_TYPE is used as the function's return type if the return + type is unknown. */ + +extern struct value *evaluate_subexp_do_call (expression *exp, + enum noside noside, + value *callee, + gdb::array_view argvec, + const char *function_name, + type *default_return_type); -extern void print_expression (struct expression *, struct ui_file *); +/* From expprint.c */ -extern char *op_string (enum exp_opcode); +extern const char *op_name (enum exp_opcode opcode); -extern void dump_raw_expression (struct expression *, struct ui_file *, char *); extern void dump_prefix_expression (struct expression *, struct ui_file *); +/* In an OP_RANGE expression, either bound could be empty, indicating + that its value is by default that of the corresponding bound of the + array or string. Also, the upper end of the range can be exclusive + or inclusive. So we have six sorts of subrange. This enumeration + type is to identify this. */ + +enum range_flag : unsigned +{ + /* This is a standard range. Both the lower and upper bounds are + defined, and the bounds are inclusive. */ + RANGE_STANDARD = 0, + + /* The low bound was not given. */ + RANGE_LOW_BOUND_DEFAULT = 1 << 0, + + /* The high bound was not given. */ + RANGE_HIGH_BOUND_DEFAULT = 1 << 1, + + /* The high bound of this range is exclusive. */ + RANGE_HIGH_BOUND_EXCLUSIVE = 1 << 2, + + /* The range has a stride. */ + RANGE_HAS_STRIDE = 1 << 3, +}; + +DEF_ENUM_FLAGS_TYPE (enum range_flag, range_flags); + #endif /* !defined (EXPRESSION_H) */