old-cross-binutils/gdb/block.h
Pierre-Marie de Rodat 63e43d3aed DWARF: handle non-local references in nested functions
GDB's current behavior when dealing with non-local references in the
context of nested fuctions is approximative:

  - code using valops.c:value_of_variable read the first available stack
    frame that holds the corresponding variable (whereas there can be
    multiple candidates for this);

  - code directly relying on read_var_value will instead read non-local
    variables in frames where they are not even defined.

This change adds the necessary context to symbol reads (to get the block
they belong to) and to blocks (the static link property, if any) so that
GDB can make the proper decisions when dealing with non-local varibale
references.

gdb/ChangeLog:

	* ada-lang.c (ada_read_var_value): Add a var_block argument
	and pass it to default_read_var_value.
	* block.c (block_static_link): New accessor.
	* block.h (block_static_link): Declare it.
	* buildsym.c (finish_block_internal): Add a static_link
	argument.  If there is a static link, associate it to the new
	block.
	(finish_block): Add a static link argument and pass it to
	finish_block_internal.
	(end_symtab_get_static_block): Update calls to finish_block and
	to finish_block_internal.
	(end_symtab_with_blockvector): Update call to
	finish_block_internal.
	* buildsym.h: Forward-declare struct dynamic_prop.
	(struct context_stack): Add a static_link field.
	(finish_block): Add a static link argument.
	* c-exp.y: Remove an obsolete comment (evaluation of variables
	already start from the selected frame, and now they climb *up*
	the call stack) and propagate the block information to the
	produced expression.
	* d-exp.y: Likewise.
	* f-exp.y: Likewise.
	* go-exp.y: Likewise.
	* jv-exp.y: Likewise.
	* m2-exp.y: Likewise.
	* p-exp.y: Likewise.
	* coffread.c (coff_symtab_read): Update calls to finish_block.
	* dbxread.c (process_one_symbol): Likewise.
	* xcoffread.c (read_xcoff_symtab): Likewise.
	* compile/compile-c-symbols.c (convert_one_symbol): Promote the
	"sym" parameter to struct block_symbol, update its uses and pass
	its block to calls to read_var_value.
	(convert_symbol_sym): Update the calls to convert_one_symbol.
	* compile/compile-loc2c.c (do_compile_dwarf_expr_to_c): Update
	call to read_var_value.
	* dwarf2loc.c (block_op_get_frame_base): New.
	(dwarf2_block_frame_base_locexpr_funcs): Implement the
	get_frame_base method.
	(dwarf2_block_frame_base_loclist_funcs): Likewise.
	(dwarf2locexpr_baton_eval): Add a frame argument and use it
	instead of the selected frame in order to evaluate the
	expression.
	(dwarf2_evaluate_property): Add a frame argument.  Update call
	to dwarf2_locexpr_baton_eval to provide a frame in available and
	to handle the absence of address stack.
	* dwarf2loc.h (dwarf2_evaluate_property): Add a frame argument.
	* dwarf2read.c (attr_to_dynamic_prop): Add a forward
	declaration.
	(read_func_scope): Record any available static link description.
	Update call to finish_block.
	(read_lexical_block_scope): Update call to finish_block.
	* findvar.c (follow_static_link): New.
	(get_hosting_frame): New.
	(default_read_var_value): Add a var_block argument.  Use
	get_hosting_frame to handle non-local references.
	(read_var_value): Add a var_block argument and pass it to the
	LA_READ_VAR_VALUE method.
	* gdbtypes.c (resolve_dynamic_range): Update calls to
	dwarf2_evaluate_property.
	(resolve_dynamic_type_internal): Likewise.
	* guile/scm-frame.c (gdbscm_frame_read_var): Update call to
	read_var_value, passing it the block coming from symbol lookup.
	* guile/scm-symbol.c (gdbscm_symbol_value): Update call to
	read_var_value (TODO).
	* infcmd.c (finish_command_continuation): Update call to
	read_var_value, passing it the block coming from symbol lookup.
	* infrun.c (insert_exception_resume_breakpoint): Likewise.
	* language.h (struct language_defn): Add a var_block argument to
	the LA_READ_VAR_VALUE method.
	* objfiles.c (struct static_link_htab_entry): New.
	(static_link_htab_entry_hash): New.
	(static_link_htab_entry_eq): New.
	(objfile_register_static_link): New.
	(objfile_lookup_static_link): New.
	(free_objfile): Free the STATIC_LINKS hashed map if needed.
	* objfiles.h: Include hashtab.h.
	(struct objfile): Add a static_links field.
	(objfile_register_static_link): New.
	(objfile_lookup_static_link): New.
	* printcmd.c (print_variable_and_value): Update call to
	read_var_value.
	* python/py-finishbreakpoint.c (bpfinishpy_init): Likewise.
	* python/py-frame.c (frapy_read_var): Update call to
	read_var_value, passing it the block coming from symbol lookup.
	* python/py-framefilter.c (extract_sym): Add a sym_block
	parameter and set the pointed value to NULL (TODO).
	(enumerate_args): Update call to extract_sym.
	(enumerate_locals): Update calls to extract_sym and to
	read_var_value.
	* python/py-symbol.c (sympy_value): Update call to
	read_var_value (TODO).
	* stack.c (read_frame_local): Update call to read_var_value.
	(read_frame_arg): Likewise.
	(return_command): Likewise.
	* symtab.h (struct symbol_block_ops): Add a get_frame_base
	method.
	(struct symbol): Add a block field.
	(SYMBOL_BLOCK): New accessor.
	* valops.c (value_of_variable): Remove frame/block handling and
	pass the block argument to read_var_value, which does this job
	now.
	(value_struct_elt_for_reference): Update calls to
	read_var_value.
	(value_of_this): Pass the block found to read_var_value.
	* value.h (read_var_value): Add a var_block argument.
	(default_read_var_value): Likewise.

gdb/testsuite/ChangeLog:

	* gdb.base/nested-subp1.exp: New file.
	* gdb.base/nested-subp1.c: New file.
	* gdb.base/nested-subp2.exp: New file.
	* gdb.base/nested-subp2.c: New file.
	* gdb.base/nested-subp3.exp: New file.
	* gdb.base/nested-subp3.c: New file.
2015-08-25 08:13:28 -04:00

347 lines
12 KiB
C

/* Code dealing with blocks for GDB.
Copyright (C) 2003-2015 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/>. */
#ifndef BLOCK_H
#define BLOCK_H
#include "dictionary.h"
/* Opaque declarations. */
struct symbol;
struct compunit_symtab;
struct block_namespace_info;
struct using_direct;
struct obstack;
struct addrmap;
/* All of the name-scope contours of the program
are represented by `struct block' objects.
All of these objects are pointed to by the blockvector.
Each block represents one name scope.
Each lexical context has its own block.
The blockvector begins with some special blocks.
The GLOBAL_BLOCK contains all the symbols defined in this compilation
whose scope is the entire program linked together.
The STATIC_BLOCK contains all the symbols whose scope is the
entire compilation excluding other separate compilations.
Blocks starting with the FIRST_LOCAL_BLOCK are not special.
Each block records a range of core addresses for the code that
is in the scope of the block. The STATIC_BLOCK and GLOBAL_BLOCK
give, for the range of code, the entire range of code produced
by the compilation that the symbol segment belongs to.
The blocks appear in the blockvector
in order of increasing starting-address,
and, within that, in order of decreasing ending-address.
This implies that within the body of one function
the blocks appear in the order of a depth-first tree walk. */
struct block
{
/* Addresses in the executable code that are in this block. */
CORE_ADDR startaddr;
CORE_ADDR endaddr;
/* The symbol that names this block, if the block is the body of a
function (real or inlined); otherwise, zero. */
struct symbol *function;
/* The `struct block' for the containing block, or 0 if none.
The superblock of a top-level local block (i.e. a function in the
case of C) is the STATIC_BLOCK. The superblock of the
STATIC_BLOCK is the GLOBAL_BLOCK. */
struct block *superblock;
/* This is used to store the symbols in the block. */
struct dictionary *dict;
/* Contains information about namespace-related info relevant to this block:
using directives and the current namespace scope. */
struct block_namespace_info *namespace_info;
};
/* The global block is singled out so that we can provide a back-link
to the compunit symtab. */
struct global_block
{
/* The block. */
struct block block;
/* This holds a pointer to the compunit symtab holding this block. */
struct compunit_symtab *compunit_symtab;
};
#define BLOCK_START(bl) (bl)->startaddr
#define BLOCK_END(bl) (bl)->endaddr
#define BLOCK_FUNCTION(bl) (bl)->function
#define BLOCK_SUPERBLOCK(bl) (bl)->superblock
#define BLOCK_DICT(bl) (bl)->dict
#define BLOCK_NAMESPACE(bl) (bl)->namespace_info
struct blockvector
{
/* Number of blocks in the list. */
int nblocks;
/* An address map mapping addresses to blocks in this blockvector.
This pointer is zero if the blocks' start and end addresses are
enough. */
struct addrmap *map;
/* The blocks themselves. */
struct block *block[1];
};
#define BLOCKVECTOR_NBLOCKS(blocklist) (blocklist)->nblocks
#define BLOCKVECTOR_BLOCK(blocklist,n) (blocklist)->block[n]
#define BLOCKVECTOR_MAP(blocklist) ((blocklist)->map)
/* Return the objfile of BLOCK, which must be non-NULL. */
extern struct objfile *block_objfile (const struct block *block);
/* Return the architecture of BLOCK, which must be non-NULL. */
extern struct gdbarch *block_gdbarch (const struct block *block);
extern struct symbol *block_linkage_function (const struct block *);
extern struct symbol *block_containing_function (const struct block *);
extern int block_inlined_p (const struct block *block);
extern int contained_in (const struct block *, const struct block *);
extern const struct blockvector *blockvector_for_pc (CORE_ADDR,
const struct block **);
extern const struct blockvector *
blockvector_for_pc_sect (CORE_ADDR, struct obj_section *,
const struct block **, struct compunit_symtab *);
extern int blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc);
extern struct call_site *call_site_for_pc (struct gdbarch *gdbarch,
CORE_ADDR pc);
extern const struct block *block_for_pc (CORE_ADDR);
extern const struct block *block_for_pc_sect (CORE_ADDR, struct obj_section *);
extern const char *block_scope (const struct block *block);
extern void block_set_scope (struct block *block, const char *scope,
struct obstack *obstack);
extern struct using_direct *block_using (const struct block *block);
extern void block_set_using (struct block *block,
struct using_direct *using_decl,
struct obstack *obstack);
extern const struct block *block_static_block (const struct block *block);
extern const struct block *block_global_block (const struct block *block);
extern struct block *allocate_block (struct obstack *obstack);
extern struct block *allocate_global_block (struct obstack *obstack);
extern void set_block_compunit_symtab (struct block *,
struct compunit_symtab *);
/* Return a property to evaluate the static link associated to BLOCK.
In the context of nested functions (available in Pascal, Ada and GNU C, for
instance), a static link (as in DWARF's DW_AT_static_link attribute) for a
function is a way to get the frame corresponding to the enclosing function.
Note that only objfile-owned and function-level blocks can have a static
link. Return NULL if there is no such property. */
extern struct dynamic_prop *block_static_link (const struct block *block);
/* A block iterator. This structure should be treated as though it
were opaque; it is only defined here because we want to support
stack allocation of iterators. */
struct block_iterator
{
/* If we're iterating over a single block, this holds the block.
Otherwise, it holds the canonical compunit. */
union
{
struct compunit_symtab *compunit_symtab;
const struct block *block;
} d;
/* If we're iterating over a single block, this is always -1.
Otherwise, it holds the index of the current "included" symtab in
the canonical symtab (that is, d.symtab->includes[idx]), with -1
meaning the canonical symtab itself. */
int idx;
/* Which block, either static or global, to iterate over. If this
is FIRST_LOCAL_BLOCK, then we are iterating over a single block.
This is used to select which field of 'd' is in use. */
enum block_enum which;
/* The underlying dictionary iterator. */
struct dict_iterator dict_iter;
};
/* Initialize ITERATOR to point at the first symbol in BLOCK, and
return that first symbol, or NULL if BLOCK is empty. */
extern struct symbol *block_iterator_first (const struct block *block,
struct block_iterator *iterator);
/* Advance ITERATOR, and return the next symbol, or NULL if there are
no more symbols. Don't call this if you've previously received
NULL from block_iterator_first or block_iterator_next on this
iteration. */
extern struct symbol *block_iterator_next (struct block_iterator *iterator);
/* Initialize ITERATOR to point at the first symbol in BLOCK whose
SYMBOL_SEARCH_NAME is NAME (as tested using strcmp_iw), and return
that first symbol, or NULL if there are no such symbols. */
extern struct symbol *block_iter_name_first (const struct block *block,
const char *name,
struct block_iterator *iterator);
/* Advance ITERATOR to point at the next symbol in BLOCK whose
SYMBOL_SEARCH_NAME is NAME (as tested using strcmp_iw), or NULL if
there are no more such symbols. Don't call this if you've
previously received NULL from block_iterator_first or
block_iterator_next on this iteration. And don't call it unless
ITERATOR was created by a previous call to block_iter_name_first
with the same NAME. */
extern struct symbol *block_iter_name_next (const char *name,
struct block_iterator *iterator);
/* Initialize ITERATOR to point at the first symbol in BLOCK whose
SYMBOL_SEARCH_NAME is NAME, as tested using COMPARE (which must use
the same conventions as strcmp_iw and be compatible with any
block hashing function), and return that first symbol, or NULL
if there are no such symbols. */
extern struct symbol *block_iter_match_first (const struct block *block,
const char *name,
symbol_compare_ftype *compare,
struct block_iterator *iterator);
/* Advance ITERATOR to point at the next symbol in BLOCK whose
SYMBOL_SEARCH_NAME is NAME, as tested using COMPARE (see
block_iter_match_first), or NULL if there are no more such symbols.
Don't call this if you've previously received NULL from
block_iterator_match_first or block_iterator_match_next on this
iteration. And don't call it unless ITERATOR was created by a
previous call to block_iter_match_first with the same NAME and COMPARE. */
extern struct symbol *block_iter_match_next (const char *name,
symbol_compare_ftype *compare,
struct block_iterator *iterator);
/* Search BLOCK for symbol NAME in DOMAIN. */
extern struct symbol *block_lookup_symbol (const struct block *block,
const char *name,
const domain_enum domain);
/* Search BLOCK for symbol NAME in DOMAIN but only in primary symbol table of
BLOCK. BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. Function is useful if
one iterates all global/static blocks of an objfile. */
extern struct symbol *block_lookup_symbol_primary (const struct block *block,
const char *name,
const domain_enum domain);
/* The type of the MATCHER argument to block_find_symbol. */
typedef int (block_symbol_matcher_ftype) (struct symbol *, void *);
/* Find symbol NAME in BLOCK and in DOMAIN that satisfies MATCHER.
DATA is passed unchanged to MATCHER.
BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. */
extern struct symbol *block_find_symbol (const struct block *block,
const char *name,
const domain_enum domain,
block_symbol_matcher_ftype *matcher,
void *data);
/* A matcher function for block_find_symbol to find only symbols with
non-opaque types. */
extern int block_find_non_opaque_type (struct symbol *sym, void *data);
/* A matcher function for block_find_symbol to prefer symbols with
non-opaque types. The way to use this function is as follows:
struct symbol *with_opaque = NULL;
struct symbol *sym
= block_find_symbol (block, name, domain,
block_find_non_opaque_type_preferred, &with_opaque);
At this point if SYM is non-NULL then a non-opaque type has been found.
Otherwise, if WITH_OPAQUE is non-NULL then an opaque type has been found.
Otherwise, the symbol was not found. */
extern int block_find_non_opaque_type_preferred (struct symbol *sym,
void *data);
/* Macro to loop through all symbols in BLOCK, in no particular
order. ITER helps keep track of the iteration, and must be a
struct block_iterator. SYM points to the current symbol. */
#define ALL_BLOCK_SYMBOLS(block, iter, sym) \
for ((sym) = block_iterator_first ((block), &(iter)); \
(sym); \
(sym) = block_iterator_next (&(iter)))
/* Macro to loop through all symbols with name NAME in BLOCK,
in no particular order. ITER helps keep track of the iteration, and
must be a struct block_iterator. SYM points to the current symbol. */
#define ALL_BLOCK_SYMBOLS_WITH_NAME(block, name, iter, sym) \
for ((sym) = block_iter_name_first ((block), (name), &(iter)); \
(sym) != NULL; \
(sym) = block_iter_name_next ((name), &(iter)))
#endif /* BLOCK_H */