[PATCH] Replace the block_found global with explicit data-flow

[Pierre-Marie de Rodat <derodat@adacore.com>]

Hi,

As Pedro suggested on gdb-patches@ (see
<https://sourceware.org/ml/gdb-patches/2015-05/msg00714.html>), this
change makes symbol lookup functions return a structure that includes
both the symbol found and the block in which it was found.  This makes
it possible to get rid of the block_found global variable and thus makes
block hunting explicit.

I saw no regression on x86_64-linux. Ok for trunk?

gdb/

         * ada-exp.y (write_object_renaming): Replace struct
         ada_symbol_info with struct symbol_in_block.  Update field
         references accordingly.
         (block_lookup, select_possible_type_sym): Likewise.
         (find_primitive_type): Likewise.  Also update call to
         ada_lookup_symbol to extract the symbol itself.
         (write_var_or_type, write_name_assoc): Likewise.
         * ada-lang.h (struct ada_symbol_info): Remove.
         (ada_lookup_symbol_list): Replace struct ada_symbol_info with
         struct symbol_in_block.
         (ada_lookup_encoded_symbol, user_select_syms): Likewise.
         (ada_lookup_symbol): Return struct symbol_in_block instead of a
         mere symbol.
         * ada-lang.c (defns_collected): Replace struct ada_symbol_info
         with struct symbol_in_block.
         (resolve_subexp, ada_resolve_function, sort_choices,
         user_select_syms, is_nonfunction, add_defn_to_vec,
         num_defns_collected, defns_collected,
         symbols_are_identical_enums, remove_extra_symbols,
         remove_irrelevant_renamings, add_lookup_symbol_list_worker,
         ada_lookup_symbol_list, ada_iterate_over_symbols,
         ada_lookup_encoded_symbol, get_var_value): Likewise.
         (symbol_in_block): Return a symbol_in_block instead of a mere
         symbol.  Replace struct ada_symbol_info with struct
         symbol_in_block.
         (ada_lookup_symbol_nonlocal): Likewise.
         (standard_lookup): Make block passing explicit through
         lookup_symbol_in_language.
         * ada-tasks.c (get_tcb_types_info): Update the calls to
         lookup_symbol_in_language to extract the mere symbol out of the
         returned value.
         (ada_tasks_inferior_data_sniffer): Likewise.
         * ax-gdb.c (gen_static_field): Likewise for the call to
         lookup_symbol.
         (gen_maybe_namespace_elt): Deal with struct symbol_in_block from
         lookup functions.
         (gen_expr): Likewise.
         * c-exp.y: Likewise.  Remove uses of block_found.
         (lex_one_token, classify_name, classify_inner_name,
         c_print_token): Likewise.
         * c-valprint.c (print_unpacked_pointer): Likewise.
         * compile/compile-c-symbols.c (convert_symbol_sym): Add a BLOCK
         parameter.  Use it to remove uses of block_found.  Deal with
         struct symbol_in_block from lookup functions.
         (gcc_convert_symbol): Likewise.  Update the call to
         convert_symbol_sym.
         * compile-object-load.c (compile_object_load): Deal with struct
         symbol_in_block from lookup functions.
         * cp-namespace.c (cp_lookup_nested_symbol_1,
         cp_lookup_nested_symbol, cp_lookup_bare_symbol,
         cp_search_static_and_baseclasses,
         cp_lookup_symbol_in_namespace, cp_lookup_symbol_via_imports,
         cp_lookup_symbol_imports_or_template,
         cp_lookup_symbol_via_all_imports, cp_lookup_symbol_namespace,
         lookup_namespace_scope, cp_lookup_nonlocal,
         find_symbol_in_baseclass): Return struct symbol_in_block instead
         of mere symbols and deal with struct symbol_in_block from lookup
         functions.
         * cp-support.c (inspect_type, replace_typedefs,
         cp_lookup_rtti_type): Deal with struct symbol_in_block from
         lookup functions.
         * cp-support.h (cp_lookup_symbol_nonlocal,
         cp_lookup_symbol_from_namespace,
         cp_lookup_symbol_imports_or_template, cp_lookup_nested_symbol):
         Return struct symbol_in_block instead of mere symbols.
         * d-exp.y (d_type_from_name, d_module_from_name, push_variable,
         push_module_name):
         Deal with struct symbol_in_block from lookup functions.  Remove
         uses of block_found.
         * eval.c (evaluate_subexp_standard): Update call to
         cp_lookup_symbol_namespace.
         * f-exp.y: Deal with struct symbol_in_block from lookup
         functions.  Remove uses of block_found.
         (yylex): Likewise.
         * gdbtypes.c (lookup_typename, lookup_struct, lookup_union,
         lookup_enum, lookup_template_type, check_typedef): Deal with
         struct symbol_in_block from lookup functions.
         * gnu-v3-abi.c (gnuv3_get_typeid_type): Likewise.
         * go-exp.y: Likewise.  Remove uses of block_found.
         (package_name_p, classify_packaged_name, classify_name):
         Likewise.
         * infrun.c (insert_exception_resume_breakpoint): Likewise.
         * jv-exp.y (push_variable): Likewise.
         * jv-lang.c (java_lookup_class, get_java_object_type): Likewise.
         * language.c (language_bool_type): Likewise.
         * language.h (struct language_defn): Update
         la_lookup_symbol_nonlocal to return a struct symbol_in_block
         rather than a mere symbol.
         * linespec.c (find_label_symbols): Deal with struct
         symbol_in_block from lookup functions.
         * m2-exp.y: Likewise.  Remove uses of block_found.
         (yylex): Likewise.
         * mi/mi-cmd-stack.c (list_args_or_locals): Likewise.
         * objc-lang.c (lookup_struct_typedef, find_imps): Likewise.
         * p-exp.y: Likewise.  Remove uses of block_found.
         (yylex): Likewise.
         * p-valprint.c (pascal_val_print): Likewise.
         * parse.c (write_dollar_variable): Likewise.  Remove uses of
         block_found.
         * parser-defs.h (struct symtoken): Turn the SYM field into a
         struct symbol_in_block.
         * printcmd.c (address_info): Deal with struct symbol_in_block
         from lookup functions.
         * python/py-frame.c (frapy_read_var): Likewise.
         * python/py-symbol.c (gdbpy_lookup_symbol,
         gdbpy_lookup_global_symbol): Likewise.
         * skip.c (skip_function_command): Likewise.
         * solib-darwin.c (darwin_lookup_lib_symbol): Return a struct
         symbol_in_block instead of a mere symbol.
         * solib-spu.c (spu_lookup_lib_symbol): Likewise.
         * solib-srv4.c (elf_lookup_lib_symbol): Likewise.
         * solib.c (solib_global_lookup): Likewise.
         * solist.h (solib_global_lookup): Likewise.
         (struct target_so_ops): Update lookup_lib_global_symbol to
         return a struct symbol_in_block rather than a mere symbol.
         * source.c (select_source_symtab): Deal with struct
         symbol_in_block from lookup functions.
         * stack.c (print_frame_args, iterate_over_block_arg_vars):
         Likewise.
         * symfile.c (set_initial_language): Likewise.
         * symtab.c (SYMBOL_LOOKUP_FAILED): Turn into a struct
         symbol_in_block.
         (SYMBOL_LOOKUP_FAILED_P): New predicate as a macro.
         (struct symbol_cache_slot): Turn the FOUND field into a struct
         symbol_in_block.
         (block_found): Remove.
         (eq_symbol_entry): Update to deal with struct symbol_in_block in
         cache slots.
         (symbol_cache_lookup): Return a struct symbol_in_block rather
         than a mere symbol.
         (symbol_cache_mark_found): Add a BLOCK parameter to fill
         appropriately the cache slots.  Update callers.
         (symbol_cache_dump): Update cache slots handling to the type
         change.
         (lookup_symbol_in_language, lookup_symbol, lookup_language_this,
         lookup_symbol_aux, lookup_local_symbol,
         lookup_symbol_in_objfile, lookup_global_symbol_from_objfile,
         lookup_symbol_in_objfile_symtabs,
         lookup_symbol_in_objfile_from_linkage_name,
         lookup_symbol_via_quick_fns, basic_lookup_symbol_nonlocal,
         lookup_symbol_in_static_block, lookup_static_symbol,
         lookup_global_symbol):
         Return a struct symbol_in_block rather than a mere symbol.  Deal
         with struct symbol_in_block from other lookup functions.  Remove
         uses of block_found.
         (lookup_symbol_in_block): Remove uses of block_found.
         (struct global_sym_lookup_data): Turn the RESULT field into a
         struct symbol_in_block.
         (lookup_symbol_global_iterator_cb): Update references to the
         RESULT field.
         (search_symbols): Deal with struct symbol_in_block from lookup
         functions.
         * symtab.h (struct symbol_in_block): New structure.
         (block_found): Remove.
         (lookup_symbol_in_language, lookup_symbol,
         basic_lookup_symbol_nonlocal, lookup_symbol_in_static_block,
         looku_static_symbol, lookup_global_symbol,
         lookup_symbol_in_block, lookup_language_this,
         lookup_global_symbol_from_objfile): Return a struct
         symbol_in_block rather than just a mere symbol.  Update comments
         to remove mentions of block_found.
         * valops.c (find_function_in_inferior,
         value_struct_elt_for_reference, value_maybe_namespace_elt,
         value_of_this):  Deal with struct symbol_in_block from lookup
         functions.
         * value.c (value_static_field, value_fn_field): Likewise.

-- 
Pierre-Marie de Rodat