Re: [PATCH 2/2] pickles: elf-32: add methods to Elf32_File

[Jose E. Marchesi]

> 2022-09-18  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
>
>       * pickles/elf-32.pk (Elf32_File.get_section_name): New method.
>       (Elf32_File.get_symbol_name): Likewise.
>       (Elf32_File.get_sections_by_name): Likewise.
>       (Elf32_File.get_sections_by_type): Likewise.
>       (Elf32_File.section_name_p): Likewise.
>       (Elf32_File.get_string): Likewise.
>       (Elf32_File.get_group_signature): Likewise.
>       (Elf32_File.get_group_signatures): Likewise.
>       (Elf32_File.get_section_group): Likewise.
> ---
>
> Hi Jose.
>
> I copied these methods from `Elf64_File' and `s/Elf64_/Elf32_/' :)
> Is this correct?

Yes, sure.  Maybe at some point the language will provide ways to avoid this
duplication, but until then... OK for master.

Thanks!

>
>
> Regards,
> Mohammad-Reza
>
>
>  ChangeLog         |  12 +++++
>  pickles/elf-32.pk | 127 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 139 insertions(+)
>
> diff --git a/ChangeLog b/ChangeLog
> index f04d36fa..305f907a 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,15 @@
> +2022-09-18  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
> +
> +     * pickles/elf-32.pk (Elf32_File.get_section_name): New method.
> +     (Elf32_File.get_symbol_name): Likewise.
> +     (Elf32_File.get_sections_by_name): Likewise.
> +     (Elf32_File.get_sections_by_type): Likewise.
> +     (Elf32_File.section_name_p): Likewise.
> +     (Elf32_File.get_string): Likewise.
> +     (Elf32_File.get_group_signature): Likewise.
> +     (Elf32_File.get_group_signatures): Likewise.
> +     (Elf32_File.get_section_group): Likewise.
> +
>  2022-09-18  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
>  
>       * pickles/elf-64.pk (Elf64_File.get_sections_by_name): Use `apush'.
> diff --git a/pickles/elf-32.pk b/pickles/elf-32.pk
> index 60acc625..38a33cad 100644
> --- a/pickles/elf-32.pk
> +++ b/pickles/elf-32.pk
> @@ -169,4 +169,131 @@ type Elf32_File =
>  
>      Elf32_Phdr[ehdr.e_phnum] phdr @ ehdr.e_phoff
>        if ehdr.e_phnum > 0;
> +
> +    /* Given an offset into the ELF file's section string table, return
> +       the string.  */
> +
> +    method get_section_name = (offset<Elf_Word,B> offset) string:
> +      {
> +        var strtab = ehdr.e_shstrndx;
> +        return string @ shdr'ios : shdr[strtab].sh_offset + offset;
> +      }
> +
> +    /* Given a symtab and an offset into its associated symbol string
> +       table, return the string.  */
> +
> +    method get_symbol_name = (Elf32_Shdr symtab, offset<Elf_Word,B> offset) 
> string:
> +      {
> +        var strtab = symtab.sh_link;
> +        return string @ shdr'ios : shdr[strtab].sh_offset + offset;
> +      }
> +
> +    /* Given a section name, return an array of section headers in the
> +       ELF file having that name.  */
> +
> +    method get_sections_by_name = (string name) Elf32_Shdr[]:
> +      {
> +        var sections = Elf32_Shdr[]();
> +
> +        for (s in shdr where get_section_name (s.sh_name) == name)
> +          apush (sections, s);
> +
> +        return sections;
> +      }
> +
> +    /* Given a section type (SHT_* value) return an array of section
> +       headers in the ELF file with that type.  */
> +
> +    method get_sections_by_type = (Elf_Word stype) Elf32_Shdr[]:
> +      {
> +        var sections = Elf32_Shdr[]();
> +
> +        for (s in shdr where s.sh_type == stype)
> +          apush (sections, s);
> +
> +        return sections;
> +      }
> +
> +    /* Given a section name, return whether it exists in this
> +       file.  */
> +
> +    method section_name_p = (string name) int:
> +      {
> +        var sections = Elf32_Shdr[]();
> +
> +        try sections = get_sections_by_name (name);
> +        catch if E_inval { return 0; }
> +
> +        return sections'length;
> +      }
> +
> +    /* Given an offset, return the string stored at that offset in the
> +       "default" string table of the ELF file.  This is the string table
> +       section named ".strtab".  If such a section doesn't exist, or it
> +       doesn't contain a string table, then raise E_inval.  */
> +    method get_string = (offset<Elf_Word,B> offset) string:
> +     {
> +       if (!section_name_p (".strtab"))
> +          raise E_inval;
> +
> +       var strtab = get_sections_by_name (".strtab")[0];
> +       return string @ strtab'ios : strtab.sh_offset + offset;
> +     }
> +
> +    /* Return the signature corresponding to a given group section.
> +       If the given section header doesn't correspond to a group
> +       section then raise E_inval.  */
> +
> +    method get_group_signature = (Elf32_Shdr section) string:
> +      {
> +        if (section.sh_type != SHT_GROUP)
> +          raise E_inval;
> +
> +        var symtab = shdr[section.sh_link];
> +        var symtab_data
> +          = Elf32_Sym [symtab.sh_size] @ shdr'ios : symtab.sh_offset;
> +        var symbol = symtab_data[section.sh_info];
> +        var symbol_name = get_symbol_name (symtab, symbol.st_name);
> +
> +        return symbol_name;
> +      }
> +
> +    /* Return an array of strings with the signatures of the section
> +       groups present in this ELF file.  */
> +
> +    method get_group_signatures = string[]:
> +      {
> +        var signatures = string[]();
> +
> +        for (section in shdr where section.sh_type == SHT_GROUP)
> +          apush (signatures, get_group_signature (section));
> +
> +        return signatures;
> +      }
> +
> +    /* Given the name of a section group, return an array with the
> +       section headers corresponding to all the sections in that
> +       group.  If the given name doesn't identify a section group in
> +       the ELF file then return an empty array.  */
> +
> +    method get_section_group = (string group_name) Elf32_Shdr[]:
> +      {
> +        var section_group = Elf32_Shdr[]();
> +
> +        var group_sections = get_sections_by_type (SHT_GROUP);
> +        for (sec in group_sections
> +             where get_group_signature (sec) == group_name)
> +          {
> +            var group_entries
> +              = (Elf_Word[sec.sh_size - sizeof (Elf_Word)]
> +                 @ sec'ios : sec.sh_offset + sizeof (Elf_Word));
> +
> +            for (entry in group_entries)
> +              apush (section_group, shdr[entry]);
> +
> +            break;
> +         }
> +
> +       return section_group;
> +     }
>    };