[Bug c++/19523] New: [4.0 Regression] DBX_USE_BINCL support broken in the C++ compiler

["ebotcazou at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The patch

2004-09-20  Matt Austern <austern@apple.com>
            Zack Weinberg  <zack@codesourcery.com>

        * c-common.c (fix_string_type): Build the unqualified array
        type unconditionally, then use c_build_qualified_type to get
        the proper const-qualified variant, and set its
        TYPE_MAIN_VARIANT to refer to the unqualified type.
        * c-lex.c (c_lex_return_raw_string): New global.
        (c_lex_with_flags): Honor it.
        * c-pragma.h: Declare it.

cp:
        * decl.c (make_rtl_for_nonlocal_decl, start_preparsed_function):
        Apply lbasename to input_filename before passing to get_fileinfo.
        * semantics.c (begin_class_definition): Likewise.
        * lex.c (handle_pragma_interface): Apply get_fileinfo to the
        correct filename.  Rename variables to be less confusing.
        (handle_pragma_implementation): Likewise.  Disable "appears
        after file is included" diagnostic.

        * parser.c (struct cp_token): Add in_system_header fiag.
        (CP_TOKEN_BLOCK_NUM_TOKENS, struct cp_token_block)
        (CP_TOKEN_BUFFER_SIZE, cp_token_cache_push_token)
        (CPP_NONE, cp_lexer_read_token): Delete.
        (struct cp_lexer): Remove first_token, string_tokens,
        main_lexer_p fields.  Clarify comments.
        (struct cp_token_cache): Now just a pair of pointers.
        (CP_LEXER_BUFFER_SIZE): New #define.
        (CPP_PURGED): New fake token type.
        (cp_lexer_new_from_token_array, cp_lexer_destroy)
        (cp_lexer_peek_token_emit_debug_info, cp_lexer_skip_purged_tokens)
        (cp_lexer_handle_pragma, cp_token_cache_new, cp_parser_string_literal):
        New functions.
        (cp_lexer_new_from_tokens): Now a simple wrapper around
        cp_lexer_new_from_token_array.
        (cp_lexer_set_source_position_from_token): Also update
        in_system_header.
        (cp_lexer_next_token, cp_lexer_prev_token, cp_lexer_advance_token):
        Don't wrap round.
        (cp_lexer_token_difference): Dont handle wrapping round.
        (cp_lexer_new_main): Enable pragma deferral and raw strings,
        read the entire translation unit through c_lex_with_flags into
        this lexer's buffer, then turn raw strings back off again.
        (cp_lexer_grow_buffer): Adjust for buffer no longer being circular.
        (cp_lexer_get_preprocessor_token): No need to handle not being
        the main lexer.  Set token->in_system_header too.
        (cp_lexer_peek_token): Skip purged tokens.  Feed pragma tokens
        to cp_lexer_handle_pragma.  No need to call cp_lexer_read_token.
        (cp_lexer_peek_nth_token): Likewise.
        (cp_lexer_purge_token): Mark the token PURGED, don't shift all
        the other tokens down.
        (cp_lexer_purge_tokens_after): Likewise.
        (cp_lexer_save_tokens, cp_lexer_rollback_tokens): Don't worry
        about there being no tokens.
        (cp_lexer_print_token): Revise to give useful information on
        all tokens.
        (struct cp_parser): Add field translate_strings_p.
        (cp_parser_new): Initialize it.
        (cp_parser_translation_unit): Destroy the lexer when done.
        (cp_parser_parameter_declaration): Restructure saving of
        default arguments.
        (cp_parser_save_member_function_body): Likewise.
        (cp_parser_check_for_invalid_template_id)
        (cp_parser_nested_name_specifier_opt, cp_parser_template_id):
        Adjust calls to cp_lexer_advance_token.
        (cp_parser_skip_to_closing_parenthesis, cp_parser_declaration):
        No need to fiddle c_lex_string_translate.
        (cp_parser_primary_expression, cp_parser_linkage_specification)
        (cp_parser_asm_definition, cp_parser_asm_specification_opt)
        (cp_parser_asm_operand_list, cp_parser_asm_clobber_list)
        Use cp_parser_string_literal.
        (cp_parser_attribute_list): Save and restore parser->translate_strings_p
        not c_lex_string_translate.
        (cp_parser_cache_group): Delete.
        (cp_parser_cache_group_1): Rename cp_parser_cache_group.  Do
        not take a cache argument.

has broken DBX_USE_BINCL support for the C++ compiler: it doesn't emit pairs of
N_BINCL/N_EINCL anymore.  This is indirectly visible in the C++ PCH testsuite on
platforms that don't eliminate unused debug info by default (so not on Darwin):

FAIL: g++.dg/pch/externc-1.C -g assembly comparison
FAIL: g++.dg/pch/externc-1.C -O2 -g assembly comparison
FAIL: g++.dg/pch/static-1.C -g assembly comparison
FAIL: g++.dg/pch/static-1.C -O2 -g assembly comparison
FAIL: g++.dg/pch/system-1.C -g assembly comparison
FAIL: g++.dg/pch/system-1.C -O2 -g assembly comparison
FAIL: g++.dg/pch/system-2.C -g assembly comparison
FAIL: g++.dg/pch/system-2.C -O2 -g assembly comparison
FAIL: g++.dg/pch/uninst.C -g assembly comparison
FAIL: g++.dg/pch/uninst.C -O2 -g assembly comparison
FAIL: g++.dg/pch/wchar-1.C -g assembly comparison
FAIL: g++.dg/pch/wchar-1.C -O2 -g assembly comparison

e.g. sparc-sun-solaris2.6 and sparc-sun-solaris2.5.1.

The problem is that dbxout.c relies on the ordered invocations of the hooks
dbxout_start_source_file, dbxout_symbol and dbxout_end_source_file to 
implement it.  Now dbxout_start_source_file and dbxout_end_source_file are 
invoked by the lexer, while dbxout_symbol is invoked by the parser, and the
patch essentially disentangled both.

See the thread http://gcc.gnu.org/ml/gcc-patches/2005-01/msg00871.html which
contains the sketch of a possible fix.

-- 
           Summary: [4.0 Regression] DBX_USE_BINCL support broken in the C++
                    compiler
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ebotcazou at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: *-*-*
  GCC host triplet: *-*-*
GCC target triplet: *-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19523