binutils-gdb/gdb/std-operator.def

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/* Standard language operator definitions for GDB, the GNU debugger.
Copyright (C) 1986-2019 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 3 of the License, or
(at your option) any later version.
This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
/* Used when it's necessary to pass an opcode which will be ignored,
or to catch uninitialized values. */
OP (OP_NULL)
/* BINOP_... operate on two values computed by following subexpressions,
replacing them by one result value. They take no immediate arguments. */
OP (BINOP_ADD) /* + */
OP (BINOP_SUB) /* - */
OP (BINOP_MUL) /* * */
OP (BINOP_DIV) /* / */
OP (BINOP_REM) /* % */
OP (BINOP_MOD) /* mod (Knuth 1.2.4) */
OP (BINOP_LSH) /* << */
OP (BINOP_RSH) /* >> */
OP (BINOP_LOGICAL_AND) /* && */
OP (BINOP_LOGICAL_OR) /* || */
OP (BINOP_BITWISE_AND) /* & */
OP (BINOP_BITWISE_IOR) /* | */
OP (BINOP_BITWISE_XOR) /* ^ */
OP (BINOP_EQUAL) /* == */
OP (BINOP_NOTEQUAL) /* != */
OP (BINOP_LESS) /* < */
OP (BINOP_GTR) /* > */
OP (BINOP_LEQ) /* <= */
OP (BINOP_GEQ) /* >= */
OP (BINOP_REPEAT) /* @ */
OP (BINOP_ASSIGN) /* = */
OP (BINOP_COMMA) /* , */
OP (BINOP_SUBSCRIPT) /* x[y] */
OP (BINOP_EXP) /* Exponentiation */
/* C++. */
OP (BINOP_MIN) /* <? */
OP (BINOP_MAX) /* >? */
/* STRUCTOP_MEMBER is used for pointer-to-member constructs.
X . * Y translates into X STRUCTOP_MEMBER Y. */
OP (STRUCTOP_MEMBER)
/* STRUCTOP_MPTR is used for pointer-to-member constructs
when X is a pointer instead of an aggregate. */
OP (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. */
OP (TYPE_INSTANCE)
/* end of C++. */
/* For Modula-2 integer division DIV. */
OP (BINOP_INTDIV)
/* +=, -=, *=, 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. */
OP (BINOP_ASSIGN_MODIFY)
/* Modula-2 standard (binary) procedures. */
OP (BINOP_VAL)
/* 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. */
OP (BINOP_CONCAT)
/* This must be the highest BINOP_ value, for expprint.c. */
OP (BINOP_END)
/* Operates on three values computed by following subexpressions. */
OP (TERNOP_COND) /* ?: */
/* A sub-string/sub-array. Ada syntax: OP1(OP2..OP3). Return
elements OP2 through OP3 of OP1. */
OP (TERNOP_SLICE)
/* 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. <OP><dimension><OP>.
The value of the first following subexpression is subscripted
by each of the next following subexpressions, one per dimension. */
OP (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 (OP_LONG)
Target FP: Use target format throughout expression parsing When parsing floating-point literals, the language parsers currently use parse_float or some equivalent routine to parse the input string into a DOUBLEST, which is then stored within a OP_DOUBLE expression node. When evaluating the expression, the OP_DOUBLE is finally converted into a value in target format. On the other hand, *decimal* floating-point literals are parsed directly into target format and stored that way in a OP_DECFLOAT expression node. In order to eliminate the DOUBLEST, this patch therefore unifies the handling of binary and decimal floating- point literals and stores them both in target format within a new OP_FLOAT expression node, replacing both OP_DOUBLE and OP_DECFLOAT. In order to store literals in target format, the parse_float routine needs to know the type of the literal. All parsers therefore need to be changed to determine the appropriate type (e.g. by detecting suffixes) *before* calling parse_float, instead of after it as today. However, this change is mostly straightforward -- again, this is already done for decimal FP today. The core of the literal parsing is moved into a new routine floatformat_from_string, mirroring floatformat_to_string. The parse_float routine now calls either floatformat_from_string or decimal_from_sting, allowing it to handle any type of FP literal. All language parsers need to be updated. Some notes on specific changes to the various languages: - C: Decimal FP is now handled in parse_float, and no longer needs to be handled specially. - D: Straightforward. - Fortran: Still used a hard-coded "atof", also replaced by parse_float now. Continues to always use builtin_real_s8 as the type of literal, even though this is probably wrong. - Go: This used to handle "f" and "l" suffixes, even though the Go language actually doesn't support those. I kept this support for now -- maybe revisit later. Note the the GDB test suite for some reason actually *verifies* that GDB supports those unsupported suffixes ... - Pascal: Likewise -- this handles suffixes that are not supported in the language standard. - Modula-2: Like Fortran, used to use "atof". - Rust: Mostly straightforward, except for a unit-testing hitch. The code use to set a special "unit_testing" flag which would cause "rust_type" to always return NULL. This makes it not possible to encode a literal into target format (which type?). The reason for this flag appears to have been that during unit testing, there is no "rust_parser" context set up, which means no "gdbarch" is available to use its types. To fix this, I removed the unit_testing flag, and instead simply just set up a dummy rust_parser context during unit testing. - Ada: This used to check sizeof (DOUBLEST) to determine which type to use for floating-point literal. This seems questionable to begin with (since DOUBLEST is quite unrelated to target formats), and in any case we need to get rid of DOUBLEST. I'm now simply always using the largest type (builtin_long_double). gdb/ChangeLog: 2017-10-25 Ulrich Weigand <uweigand@de.ibm.com> * doublest.c (floatformat_from_string): New function. * doublest.h (floatformat_from_string): Add prototype. * std-operator.def (OP_DOUBLE, OP_DECFLOAT): Remove, replace by ... (OP_FLOAT): ... this. * expression.h: Do not include "doublest.h". (union exp_element): Replace doubleconst and decfloatconst by new element floatconst. * ada-lang.c (resolve_subexp): Handle OP_FLOAT instead of OP_DOUBLE. (ada_evaluate_subexp): Likewise. * eval.c (evaluate_subexp_standard): Handle OP_FLOAT instead of OP_DOUBLE and OP_DECFLOAT. * expprint.c (print_subexp_standard): Likewise. (dump_subexp_body_standard): Likewise. * breakpoint.c (watchpoint_exp_is_const): Likewise. * parse.c: Include "dfp.h". (write_exp_elt_dblcst, write_exp_elt_decfloatcst): Remove. (write_exp_elt_floatcst): New function. (operator_length_standard): Handle OP_FLOAT instead of OP_DOUBLE and OP_DECFLOAT. (operator_check_standard): Likewise. (parse_float): Do not accept suffix. Take type as input. Return bool. Return target format buffer instead of host DOUBLEST. Use floatformat_from_string and decimal_from_string to parse either binary or decimal floating-point types. (parse_c_float): Remove. * parser-defs.h: Do not include "doublest.h". (write_exp_elt_dblcst, write_exp_elt_decfloatcst): Remove. (write_exp_elt_floatcst): Add prototype. (parse_float): Update prototype. (parse_c_float): Remove. * c-exp.y: Do not include "dfp.h". (typed_val_float): Use byte buffer instead of DOUBLEST. (typed_val_decfloat): Remove. (DECFLOAT): Remove. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Update to new parse_float interface. Parse suffixes and determine type before calling parse_float. Handle decimal and binary FP types the same way. * d-exp.y (typed_val_float): Use byte buffer instead of DOUBLEST. (FLOAT_LITERAL): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Update to new parse_float interface. Parse suffixes and determine type before calling parse_float. * f-exp.y: Replace dval by typed_val_float. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Use parse_float instead of atof. * go-exp.y (typed_val_float): Use byte buffer instead of DOUBLEST. (parse_go_float): Remove. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Call parse_float instead of parse_go_float. Parse suffixes and determine type before calling parse_float. * p-exp.y (typed_val_float): Use byte buffer instead of DOUBLEST. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Update to new parse_float interface. Parse suffixes and determine type before calling parse_float. * m2-exp.y: Replace dval by byte buffer val. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. (parse_number): Call parse_float instead of atof. * rust-exp.y (typed_val_float): Use byte buffer instead of DOUBLEST. (lex_number): Call parse_float instead of strtod. (ast_dliteral): Use OP_FLOAT instead of OP_DOUBLE. (convert_ast_to_expression): Handle OP_FLOAT instead of OP_DOUBLE. Use write_exp_elt_floatcst. (unit_testing): Remove static variable. (rust_type): Do not check unit_testing. (rust_lex_tests): Do not set uint_testing. Set up dummy rust_parser. * ada-exp.y (type_float, type_double): Remove. (typed_val_float): Use byte buffer instead of DOUBLEST. (FLOAT): Use OP_FLOAT and write_exp_elt_floatcst. * ada-lex.l (processReal): Use parse_float instead of sscanf.
2017-10-25 15:32:23 +02:00
/* OP_FLOAT is similar but takes a floating-point constant encoded in
the target format for the given type instead of a long. */
OP (OP_FLOAT)
/* 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 (OP_VAR_VALUE)
/* OP_VAR_ENTRY_VALUE takes one struct symbol * in the following element,
followed by another OP_VAR_ENTRY_VALUE, making three exp_elements.
somename@entry may mean parameter value as present at the entry of the
DWARF-5: call sites this patch updates all call sites related DWARF-5 renames. gdb/ChangeLog 2017-02-20 Jan Kratochvil <jan.kratochvil@redhat.com> * block.c (call_site_for_pc): Rename DW_OP_GNU_*, DW_TAG_GNU_* and DW_AT_GNU_*. * common/common-exceptions.h (enum errors): Likewise. * dwarf2-frame.c (class dwarf_expr_executor): Likewise. * dwarf2expr.c (dwarf_block_to_dwarf_reg) (dwarf_expr_context::execute_stack_op): Likewise. * dwarf2expr.h (struct dwarf_expr_context, struct dwarf_expr_piece): Likewise. * dwarf2loc.c (dwarf_evaluate_loc_desc::get_base_type) (dwarf_evaluate_loc_desc::push_dwarf_reg_entry_value) (show_entry_values_debug, call_site_to_target_addr) (func_addr_to_tail_call_list, func_verify_no_selftailcall) (dwarf_expr_reg_to_entry_parameter, dwarf_entry_parameter_to_value) (entry_data_value_free_closure, value_of_dwarf_reg_entry) (value_of_dwarf_block_entry, indirect_pieced_value) (symbol_needs_eval_context::push_dwarf_reg_entry_value): (disassemble_dwarf_expression): Likewise. * dwarf2read.c (process_die, inherit_abstract_dies) (read_call_site_scope): Likewise. * gdbtypes.h (struct func_type, struct call_site_parameter) (struct call_site): Likewise. * stack.c (read_frame_arg): Likewise. * std-operator.def (OP_VAR_ENTRY_VALUE): Likewise. gdb/doc/ChangeLog 2017-02-20 Jan Kratochvil <jan.kratochvil@redhat.com> * gdb.texinfo (Print Settings, Tail Call Frames): Rename DW_OP_GNU_*, DW_TAG_GNU_* and DW_AT_GNU_*. gdb/testsuite/ChangeLog 2017-02-20 Jan Kratochvil <jan.kratochvil@redhat.com> * gdb.arch/amd64-entry-value-param-dwarf5.S: New file. * gdb.arch/amd64-entry-value-param-dwarf5.c: New file. * gdb.arch/amd64-entry-value-param-dwarf5.exp: New file. * gdb.arch/amd64-entry-value.exp: Rename DW_OP_GNU_*, DW_TAG_GNU_* and DW_AT_GNU_*.
2017-02-20 20:53:21 +01:00
current function. Implemented via DW_OP_entry_value. */
OP (OP_VAR_ENTRY_VALUE)
Introduce OP_VAR_MSYM_VALUE The previous patch left GDB with an inconsistency. While with normal expression evaluation the "unknown return type" error shows the name of the function that misses debug info: (gdb) p getenv ("PATH") 'getenv' has unknown return type; cast the call to its declared return type ^^^^^^ which can by handy in more complicated expressions, "ptype" does not: (gdb) ptype getenv ("PATH") function has unknown return type; cast the call to its declared return type ^^^^^^^^ This commit is a step toward fixing it. The problem is that while evaluating the expression above, we have no reference to the minimal symbol where we could extract the name from. This is because the resulting expression tree has no reference to the minsym at all. During parsing, the type and address of the minsym are extracted and an UNOP_MEMVAL / UNOP_MEMVAL_TLS operator is generated (see write_exp_elt_msym). With "set debug expression", here's what you see: 0 OP_FUNCALL Number of args: 0 3 UNOP_MEMVAL Type @0x565334a51930 (<text variable, no debug info>) 6 OP_LONG Type @0x565334a51c60 (__CORE_ADDR), value 140737345035648 (0x7ffff7751d80) The "print" case finds the function name, because call_function_by_hand looks up the function by address again. However, for "ptype", we don't reach that code, because obviously we don't really call the function. Unlike minsym references, references to variables with debug info have a pointer to the variable's symbol in the expression tree, with OP_VAR_VALUE: (gdb) ptype main() ... 0 OP_FUNCALL Number of args: 0 3 OP_VAR_VALUE Block @0x0, symbol @0x559bbbd9b358 (main(int, char**)) ... so I don't see why do minsyms need to be different. So to prepare for fixing the missing function name issue, this commit adds a new OP_VAR_MSYM_VALUE operator that mimics OP_VAR_VALUE, except that it's for minsyms instead of debug symbols. For infcalls, we now get expressions like these: 0 OP_FUNCALL Number of args: 0 3 OP_VAR_MSYM_VALUE Objfile @0x1e41bf0, msymbol @0x7fffe599b000 (getenv) In the following patch, we'll make OP_FUNCALL extract the function name from the symbol stored in OP_VAR_VALUE/OP_VAR_MSYM_VALUE. OP_VAR_MSYM_VALUE will be used more in a later patch in the series too. gdb/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * ada-lang.c (resolve_subexp): Handle OP_VAR_MSYM_VALUE. * ax-gdb.c (gen_msym_var_ref): New function. (gen_expr): Handle OP_VAR_MSYM_VALUE. * eval.c (evaluate_var_msym_value): New function. * eval.c (evaluate_subexp_standard): Handle OP_VAR_MSYM_VALUE. <OP_FUNCALL>: Extract function name from symbol/minsym and pass it to call_function_by_hand. * expprint.c (print_subexp_standard, dump_subexp_body_standard): Handle OP_VAR_MSYM_VALUE. (union exp_element) <msymbol>: New field. * minsyms.h (struct type): Forward declare. (find_minsym_type_and_address): Declare. * parse.c (write_exp_elt_msym): New function. (write_exp_msymbol): Delete, refactored as ... (find_minsym_type_and_address): ... this new function. (write_exp_msymbol): Reimplement using OP_VAR_MSYM_VALUE. (operator_length_standard, operator_check_standard): Handle OP_VAR_MSYM_VALUE. * std-operator.def (OP_VAR_MSYM_VALUE): New.
2017-09-04 21:21:13 +02:00
/* OP_VAR_MSYM_VALUE takes one struct objfile * in the following
element, and one struct minimal_symbol * in the following
exp_element, followed by another OP_VAR_MSYM_VALUE, making four
exp_elements. */
OP (OP_VAR_MSYM_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 (OP_LAST)
/* OP_REGISTER is followed by a string in the next exp_element.
This is the name of a register to fetch. */
OP (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 (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 (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 (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
<name> ( <stuff> ). */
OP (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 (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 (OP_STRING)
/* 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 (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. */
OP (UNOP_CAST)
/* Like UNOP_CAST, but the type is a subexpression. */
OP (UNOP_CAST_TYPE)
/* The C++ dynamic_cast operator. */
OP (UNOP_DYNAMIC_CAST)
/* The C++ reinterpret_cast operator. */
OP (UNOP_REINTERPRET_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. */
OP (UNOP_MEMVAL)
/* Like UNOP_MEMVAL, but the type is supplied as a subexpression. */
OP (UNOP_MEMVAL_TYPE)
/* UNOP_... operate on one value from a following subexpression
and replace it with a result. They take no immediate arguments. */
OP (UNOP_NEG) /* Unary - */
OP (UNOP_LOGICAL_NOT) /* Unary ! */
OP (UNOP_COMPLEMENT) /* Unary ~ */
OP (UNOP_IND) /* Unary * */
OP (UNOP_ADDR) /* Unary & */
OP (UNOP_PREINCREMENT) /* ++ before an expression */
OP (UNOP_POSTINCREMENT) /* ++ after an expression */
OP (UNOP_PREDECREMENT) /* -- before an expression */
OP (UNOP_POSTDECREMENT) /* -- after an expression */
OP (UNOP_SIZEOF) /* Unary sizeof (followed by expression) */
OP (UNOP_ALIGNOF) /* Unary alignof (followed by expression) */
OP (UNOP_PLUS) /* Unary plus */
OP (UNOP_CAP) /* Modula-2 standard (unary) procedures */
OP (UNOP_CHR)
OP (UNOP_ORD)
OP (UNOP_ABS)
OP (UNOP_FLOAT)
OP (UNOP_HIGH)
OP (UNOP_MAX)
OP (UNOP_MIN)
OP (UNOP_ODD)
OP (UNOP_TRUNC)
OP (OP_BOOL) /* Modula-2 builtin BOOLEAN type */
OP (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. */
OP (STRUCTOP_STRUCT)
OP (STRUCTOP_PTR)
/* Anonymous field access, e.g. "foo.3". Used in Rust. */
OP (STRUCTOP_ANONYMOUS)
/* C++: OP_THIS is just a placeholder for the class instance variable.
It just comes in a tight (OP_THIS, OP_THIS) pair. */
OP (OP_THIS)
/* Objective C: "@selector" pseudo-operator. */
OP (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 (OP_SCOPE)
Handle "p S::method()::static_var" in the C++ parser This commit makes "print S::method()::static_var" actually find the debug symbol for static_var. Currently, you get: (gdb) print S::method()::static_var A syntax error in expression, near `'. Quoting the whole string would seemingly work before the previous patch that made GDB stop assuming int for no-debug-info variables: (gdb) p 'S::method()::static_var' $1 = 1 ... except that's incorrect output, because: (gdb) ptype 'S::method()::static_var' type = <data variable, no debug info> The way to make it work correctly currently is by quoting the function/method part, like this: (gdb) print 'S::method()'::static_var $1 = {i1 = 1, i2 = 2, i3 = 3} (gdb) ptype 'S::method()'::static_var type = struct aggregate { int i1; int i2; int i3; } At least after the "stop assuming int" patch, this is what we now get: (gdb) p 'S::method()::static_var' 'S::method()::static_var' has unknown type; cast it to its declared type (gdb) p (struct aggregate) 'S::method()::static_var' $1 = {i1 = 1, i2 = 2, i3 = 3} However, IMO, users shouldn't really have to care about any of this. GDB should Just Work, without quoting, IMO. So here's a patch that implements support for that in the C++ parser. With this patch, you now get: (gdb) p S::method()::S_M_s_var_aggregate $1 = {i1 = 1, i2 = 2, i3 = 3} (gdb) ptype S::method()::S_M_s_var_aggregate type = struct aggregate { int i1; int i2; int i3; } gdb/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> (%type <voidval>): Add function_method. * c-exp.y (exp): New production for calls with no arguments. (function_method, function_method_void_or_typelist): New productions. (exp): New production for "method()::static_var". * eval.c (evaluate_subexp_standard): Handle OP_FUNC_STATIC_VAR. * expprint.c (print_subexp_standard, dump_subexp_body_standard): Handle OP_FUNC_STATIC_VAR. * parse.c (operator_length_standard): Handle OP_FUNC_STATIC_VAR. * std-operator.def (OP_FUNC_STATIC_VAR): New. gdb/testsuite/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * gdb.base/local-static.c: New. * gdb.base/local-static.cc: New. * gdb.base/local-static.exp: New.
2017-09-04 21:21:15 +02:00
/* OP_FUNC_STATIC_VAR refers to a function local static variable. The
function is taken from the following subexpression. The length of
the variable name as a 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.
Note this is used by C++, but not C. The C parser handles local
static variables in the parser directly. Also, this is only used
in C++ if the function/method name is not quoted, like e.g.:
p S:method()::var
p S:method() const::var
If the function/method is quoted like instead:
p 'S:method() const'::var
then the C-specific handling directly in the parser takes over (see
block/variable productions).
Handle "p 'S::method()::static_var'" (quoted) in symbol lookup While the previous commit made "p method()::static_var" (no single-quotes) Just Work, if users (or frontends) try wrapping the expression with quotes, they'll get: (gdb) p 'S::method()::static_var' 'S::method()::static_var' has unknown type; cast it to its declared type even if we _do_ have debug info for that variable. That's better than the bogus/confusing value what GDB would print before the stop-assuming-int patch: (gdb) p 'S::method()::static_var' $1 = 1 but I think it'd still be nice to make this case Just Work too. In this case, due to the quoting, the C/C++ parser (c-exp.y) interprets the whole expression/string as a single symbol name, and we end up calling lookup_symbol on that name. There's no debug symbol with that fully-qualified name, but since the compiler gives the static variable a mangled linkage name exactly like the above, it appears in the mininal symbols: $ nm -A local-static | c++filt | grep static_var local-static:0000000000601040 d S::method()::static_var ... and that's what GDB happens to find/print. This only happens in C++, note, since for C the compiler uses different linkage names: local-static-c:0000000000601040 d static_var.1848 So while (in C++, not C) function local static variables are given a mangled name that demangles to the same syntax that GDB documents/expects as the way to access function local statics, there's no global symbol in the debug info with that name at all. The debug info for a static local variable for a non-inline function looks like this: <1><2a1>: Abbrev Number: 19 (DW_TAG_subprogram) ... <2><2f7>: Abbrev Number: 20 (DW_TAG_variable) <2f8> DW_AT_name : (indirect string, offset: 0x4e9): static_var <2fc> DW_AT_decl_file : 1 <2fd> DW_AT_decl_line : 64 <2fe> DW_AT_type : <0x25> <302> DW_AT_location : 9 byte block: 3 40 10 60 0 0 0 0 0 (DW_OP_addr: 601040) and for an inline function, it looks like this (linkage name run through c++filt for convenience): <2><21b>: Abbrev Number: 16 (DW_TAG_variable) <21c> DW_AT_name : (indirect string, offset: 0x21a): static_var <220> DW_AT_decl_file : 1 <221> DW_AT_decl_line : 48 <222> DW_AT_linkage_name: (indirect string, offset: 0x200): S::inline_method()::static_var <226> DW_AT_type : <0x25> <22a> DW_AT_external : 1 <22a> DW_AT_location : 9 byte block: 3 a0 10 60 0 0 0 0 0 (DW_OP_addr: 6010a0) (The inline case makes the variable external so that the linker can merge the different inlined copies. It seems like GCC never outputs the linkage name for non-extern globals.) When we read the DWARF, we record the static_var variable as a regular variable of the containing function's block. This makes stopping in the function and printing the variable as usual. The variable just so happens to have a memory address as location. So one way to make "p 'S::method()::static_var'" work would be to record _two_ copies of the symbols for these variables. One in the function's scope/block, with "static_var" as name, as we currently do, and another in the static or global blocks (depending on whether the symbol is external), with a fully-qualified name. I wrote a prototype patch for that, and it works. For the non-inline case above, since the debug info doesn't point to the linkage same, that patch built the physname of the static local variable as the concat of the physname of the containing function, plus "::", plus the variable's name. We could make that approach work for C too, though it kind of feels awkward to record fake symbol names like that in C. The other approach I tried is to change the C++ symbol lookup routines instead. This is the approach this commit takes. We can already lookup up symbol in namespaces and classes, so this feels like a good fit, and was easy enough. The advantage is that this doesn't require recording extra symbols. The test in gdb.cp/m-static.exp that exposed the need for this is removed, since the same functionality is now covered by gdb.cp/local-static.exp. gdb/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * cp-namespace.c (cp_search_static_and_baseclasses): Handle function/method scopes; lookup the nested name as a function local static variable. gdb/testsuite/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * gdb.base/local-static.exp: Also test with class::method::variable wholly quoted. * gdb.cp/m-static.exp (class::method::variable): Remove test.
2017-09-04 21:21:16 +02:00
Also, if the whole function+var is quoted like this:
p 'S:method() const::var'
then the whole quoted expression is interpreted as a single symbol
name and we don't use OP_FUNC_STATIC_VAR either. In that case, the
C++-specific symbol lookup routines take care of the
function-local-static search. */
Handle "p S::method()::static_var" in the C++ parser This commit makes "print S::method()::static_var" actually find the debug symbol for static_var. Currently, you get: (gdb) print S::method()::static_var A syntax error in expression, near `'. Quoting the whole string would seemingly work before the previous patch that made GDB stop assuming int for no-debug-info variables: (gdb) p 'S::method()::static_var' $1 = 1 ... except that's incorrect output, because: (gdb) ptype 'S::method()::static_var' type = <data variable, no debug info> The way to make it work correctly currently is by quoting the function/method part, like this: (gdb) print 'S::method()'::static_var $1 = {i1 = 1, i2 = 2, i3 = 3} (gdb) ptype 'S::method()'::static_var type = struct aggregate { int i1; int i2; int i3; } At least after the "stop assuming int" patch, this is what we now get: (gdb) p 'S::method()::static_var' 'S::method()::static_var' has unknown type; cast it to its declared type (gdb) p (struct aggregate) 'S::method()::static_var' $1 = {i1 = 1, i2 = 2, i3 = 3} However, IMO, users shouldn't really have to care about any of this. GDB should Just Work, without quoting, IMO. So here's a patch that implements support for that in the C++ parser. With this patch, you now get: (gdb) p S::method()::S_M_s_var_aggregate $1 = {i1 = 1, i2 = 2, i3 = 3} (gdb) ptype S::method()::S_M_s_var_aggregate type = struct aggregate { int i1; int i2; int i3; } gdb/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> (%type <voidval>): Add function_method. * c-exp.y (exp): New production for calls with no arguments. (function_method, function_method_void_or_typelist): New productions. (exp): New production for "method()::static_var". * eval.c (evaluate_subexp_standard): Handle OP_FUNC_STATIC_VAR. * expprint.c (print_subexp_standard, dump_subexp_body_standard): Handle OP_FUNC_STATIC_VAR. * parse.c (operator_length_standard): Handle OP_FUNC_STATIC_VAR. * std-operator.def (OP_FUNC_STATIC_VAR): New. gdb/testsuite/ChangeLog: 2017-09-04 Pedro Alves <palves@redhat.com> * gdb.base/local-static.c: New. * gdb.base/local-static.cc: New. * gdb.base/local-static.exp: New.
2017-09-04 21:21:15 +02:00
OP (OP_FUNC_STATIC_VAR)
/* 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 (OP_TYPE)
/* An un-looked-up identifier. */
OP (OP_NAME)
/* An Objective C Foundation Class NSString constant. */
OP (OP_OBJC_NSSTRING)
/* An array range operator (in Fortran 90, for "exp:exp", "exp:",
":exp" and ":"). */
OP (OP_RANGE)
/* OP_ADL_FUNC specifies that the function is to be looked up in an
Argument Dependent manner (Koenig lookup). */
OP (OP_ADL_FUNC)
/* The typeof operator. This has one expression argument, which is
evaluated solely for its type. */
OP (OP_TYPEOF)
/* The decltype operator. This has one expression argument, which is
evaluated solely for its type. This is similar to typeof, but has
slight different semantics. */
OP (OP_DECLTYPE)
/* The typeid operator. This has one expression argument. */
OP (OP_TYPEID)
/* This is used for the Rust [expr; N] form of array construction. It
takes two expression arguments. */
OP (OP_RUST_ARRAY)