Add a new command line option '--require-defined' to the linker. This
option operates identically to the '--undefined' option, except that if
the symbol is not defined in the final output file then the linker will
exit with an error.
When making use of --gc-section, or just when trying to pull in parts of
a library, it is not uncommon for a user to use the '--undefined'
command line option to specify a symbol that the user then expects to be
defined by one of the object files supplied to the link.
However, if for any reason the symbol is not satisfied by an object
provided to the link the user will be left with an undefined symbol in
the output file, instead of a defined symbol.
In some cases the above behaviour is what the user wants, in other cases
though we can do better. The '--require-defined' option tries to fill
this gap. The symbol passed to the '--require-defined' option is
treated exactly as if the symbol was passed to '--undefined', however,
before the linker exits a check is made that all symbols passed to
'--require-defined' are actually defined, if any are not then the link
will fail with an error.
ld/ChangeLog:
* ld.texinfo (Options): Document --require-defined option.
* ldlang.c (struct require_defined_symbol): New structure.
(require_defined_symbol_list): New variable.
(ldlang_add_require_defined): New function.
(ldlang_check_require_defined_symbols): New function.
(lang_process): Check required symbols are defined.
* ldlang.h (ldlang_add_require_defined): Declare.
* ldlex.h (enum option_values): Add OPTION_REQUIRE_DEFINED_SYMBOL.
* lexsup.c (ld_options): Add '--require-defined' entry.
(parse_args): Handle '--require-defined' entry.
* NEWS: Mention new '--require-defined' option.
ld/testsuite/ChangeLog:
* ld-undefined/require-defined-1.d: New file.
* ld-undefined/require-defined-2.d: New file.
* ld-undefined/require-defined-3.d: New file.
* ld-undefined/require-defined-4.d: New file.
* ld-undefined/require-defined-5.d: New file.
* ld-undefined/require-defined.exp: New file.
* ld-undefined/require-defined.s: New file.
ld * ld.h (struct ld_config_type): Add new field: warn_orphan.
* ldlex.h (enum option_values): Add OPTION_WARN_ORPHAN and
OPTION_NO_WARN_ORPHAN.
* lexsup.c (ld_options): Add --warn-orphan and --no-warn-orphan.
(parse_args): Handle the new options.
* ldemul.c (ldemul_place_orphan): If requested, generate a warning
message when an orphan section is placed in the output file.
* ld.texinfo: Document the new option.
* NEWS: Mention the new feature.
tests * ld-elf/orphan-5.l: New test - checks the linker's output with
--warn-orphan enabled.
* ld-elf/elf.exp: Run the new test.
* ldlex.l (INPUTLIST): New start condition.
(comment pattern, ",", "(", ")", "AS_NEEDED")
({FILENAMECHAR1}{FILENAMECHAR}*, "-l"{FILENAMECHAR}+)
(quoted string pattern, whitespace pattern): Add INPUTLIST to
valid start conditions.
(<INPUTLIST>"="{FILENAMECHAR1}{FILENAMECHAR}*): New NAME rule.
(ldlex_inputlist): New start-condition-setter function.
* ldgram.y (input_list1): Rename from input_list. All recursive
use changed.
(input_list): New wrapper rule for input_list1, setting
INPUTLIST lexer state for the duration of parsing input_list1.
All this to say INPUT(=/path/to/file) and not be forced to use
INPUT("=/path/to/file") whenever there's a need to force a sysroot-
prefix. Still, IMHO it seems better to make use of a previously
invalid syntax and not only change the meaning of quoted =-prefixed
paths (though arguably that's not very useful before this patchset).
This got a little bit hairier than I'd expected: I had to add a new
lexer state (aka. start condition) to avoid a first "=" being lexed as
the token "=", despite that not making sense in constructs expecting
file-names in the first place. (The grammar doesn't allow for
expressions in any part of those lists.) I guess I *could* have made
it work using that token anyway, but I didn't like the idea that you
would be able to separate the "=" from the rest of the file-name with
whitespace.
* ld.h (parsing_defsym): Delete.
* ldexp.c (exp_intop, exp_bigintop, exp_relop): Set type.filename.
(fold_binary, fold_name, exp_fold_tree_1, exp_get_vma, exp_get_fill,
exp_get_abs_int): Add tree arg for %S in error messages. Don't
fudge lineno.
(exp_binop, exp_unop, exp_nameop, exp_assop, exp_assert): Copy
type.filename from sub-tree.
(exp_trinop): Likewise, and use "cond" rather than "lhs".
* ldexp.h (node_type): Add filename field to struct.
* ldfile.c (ldfile_input_filename): Delete. Remove all refs.
* ldfile.h (ldfile_input_filename): Delete.
* ldgram.y (phdr_type, phdr_qualifiers, yyerror): Add NULL arg for
%S in error messages.
* ldemul.c (syslib_default, hll_default): Likewise.
* ldlang.c (lang_memory_region_lookup, lang_memory_region_alias,
lang_get_regions, lang_new_phdr): Likewise.
(lang_size_sections_1): Pass addr_tree for %S.
* ldlex.h (lex_redirect): Update prototype.
(ldlex_filename): Declare.
* ldlex.l (<EOF>): Don't set ldfile_input_filename.
(lex_redirect): Add fake_filename and count params. Push
fake_filename to file_name_stack and init lineno from count.
(ldlex_filename): New function.
(lex_warn_invalid): Use above.
* ldmain.c (main): Update lex_redirect call.
* ldmisc.c (vfinfo <%S>): Take file name and line number from
etree_type arg, or use current if arg is NULL.
* lexsup.c (parsing_defsym): Delete.
(parse_args <OPTION_DEFSYM>): Update lex_redirect call.
