[LTO][PATCH] Generate and use the .debug_str section when compiling -flto

["William Maddox" <maddox at google dot com>]

This patch modifies the LTO reader to read the .debug_str section,
if present, and to resolve DW_FORM_strp attributes.  It also removes
the workaround in dwarf2out.c for the previous inability of LTO to grok
string table references.

--Bill

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gcc/Changelog:

        * dwarf2out.c (AT_string_form): Remove code to suppress
       the use of the DWARF string table.

gcc/lto/Changelog:

        * lto.c (lto_str_fd_init): New function.
        (lto_str_fd_close): New function.
        (lto_file_init): Call lto_str_fd_init.
        (lto_file_close): Call lto_str_fd_close.
        (lto_str_read): New function. Read debug string table.
        (lto_str_lookup): New function. Get string for debug
        string table offset.
        (lto_read_form): Recognize DW_FORM_strp.
        (lto_file_read): Invoke lto_str_read.

        * lto-elf.c (lto_elf_file_open): Read raw section data
        for the .debug_str section, if present.

        * lto.h (struct lto_str_fd_struct): New struct.
        (struct lto_file_struct): Added new field DEBUG_STR
        to hold the file descriptor for the debug string table.

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Attachment: string-table-patch.txt
Description: Text document