Commit Graph

4 Commits

Author SHA1 Message Date
Fangrui Song b28412d539 [llvm-objcopy][ELF] Add --set-section-type
The request is mentioned on D129053. I feel that having this functionality is
mildly useful (not strong).

* Rename .ctors to .init_array and change sh_type to SHT_INIT_ARRAY (GNU objcopy
  detects the special name but we don't).
* Craft tests for a new SHT_LLVM_* extension

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D129337
2022-07-13 10:04:21 -07:00
James Henderson 1562e4552c [llvm-objcopy][llvm-strip][test] Improve testing
This patch adds a number of new test cases that cover various
llvm-objcopy and llvm-strip features that had missing test coverage of
various descriptions:
* --add-section - checked the shdr properties, not just the content.
* Dedicated test case for --add-symbol when there are many sections.
* Show that --change-start accepts negative values without overflow.
  This was previously present but got lost between review versions.
* --dump-section - show that multiple sections can be dumped
  simultaneously to different files, and that an error is reported when
  a section cannot be found.
* --globalize-symbol(s) - show that symbols that are not mentioned are
  not globalized, if they would otherwise be, and that missing symbols
  from the list do not cause problems.
* --keep-global-symbol - show that the --regex option can be used in
  conjunction with this option.
* --keep-symbol - show that the --regex option can be used in
  conjunction with this option.
* --localize-symbol(s) - show that symbols that are not mentioned are
  not localized, if they would otherwise be, and that missing symbols
  from the list do not cause problems.
* --prefix-alloc-sections - show the behaviour of an empty string
  argument and multiple arguments.
* --prefix-symbols - show the behaviour of an empty string argument and
  multiple arguments. Also show the option applies to undefined symbols.
* --redefine-symbol - show that symbols with no name can be renamed,
  that it is not an error if a symbol is not specified, and that the
  option doesn't chain (i.e. --redefine-sym a=b --redefine-sym b=c does
  not redefine a as c).
* --rename-section - show that all section flags are preserved if none
  are specified. Also show that the option does not chain.
* --set-section-alignment - show that only specified sections have
  their alignments changed.
* --set-section-flags - show which section flags are preserved when this
  option is used. Also show that unspecified sections are not affected.
* --preserve-dates - show that -p is an alias of --preserve-dates.
* --strip-symbol - show that --regex works with this option for
  llvm-objcopy as well as llvm-strip.
* --strip-unneeded-symbol(s) - show more clearly that needed symbols are
  not stripped even if requested by this option.
* --allow-broken-links - show the sh_link of a symbol table is set to 0
  when its string table has been removed when this option is specified.
* --weaken-symbol(s) - show that symbols that are not mentioned are not
  weakened, if they would otherwise be, and that missing symbols from
  the list do not cause problems.
* --wildcard - show the wildcard behaviour for several options that were
  previously unchecked.

Reviewed by: alexshap

Differential Revision: https://reviews.llvm.org/D97666
2021-03-04 11:32:27 +00:00
georgerim de3cef1d5d [yaml2obj, obj2yaml] - Add support for SHT_NOTE sections.
SHT_NOTE is the section that consists of
namesz, descsz, type, name + padding, desc + padding data.
This patch teaches yaml2obj, obj2yaml to dump and parse them.

This patch implements the section how it is described here:
https://docs.oracle.com/cd/E23824_01/html/819-0690/chapter6-18048.html
Which says: "For 64–bit objects and 32–bit objects, each entry is an array of 4-byte words in
the format of the target processor"

The official specification is different
http://www.sco.com/developers/gabi/latest/ch5.pheader.html#note_section
And says: "n 64-bit objects (files with e_ident[EI_CLASS] equal to ELFCLASS64), each entry is an array
of 8-byte words in the format of the target processor. In 32-bit objects (files with e_ident[EI_CLASS]
equal to ELFCLASS32), each entry is an array of 4-byte words in the format of the target processor"

Since LLVM uses the first, 32-bit way, this patch follows it.

Differential revision: https://reviews.llvm.org/D68983
2019-10-25 13:25:56 +03:00
Fangrui Song 671fb34358 [llvm-objcopy] Add --set-section-alignment
Fixes PR43181. This option was recently added to GNU objcopy (binutils
PR24942).

`llvm-objcopy -I binary -O elf64-x86-64 --set-section-alignment .data=8` can set the alignment of .data.

Reviewed By: grimar, jhenderson, rupprecht

Differential Revision: https://reviews.llvm.org/D67656

llvm-svn: 373461
2019-10-02 12:41:25 +00:00