This patch resolves crash that occurs when user wanted to remove all
symbols and add a brand new one using:
```
llvm-objcopy -R .symtab --add-symbol foo=1234 in.o out.o
```
Before these changes the symbol table internally being null when adding
new symbols. For now we will regenerate symtab in this case.
This fixes: https://bugs.llvm.org/show_bug.cgi?id=43930
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D82935
SHT_GROUP sections contain a reference to a symbol indicating their
"signature" symbol. The symbol table containing this symbol is referred
to by the group section's sh_link field. If llvm-objcopy is instructed
to remove the symbol table, it will emit an error.
This fixes https://bugs.llvm.org/show_bug.cgi?id=46153.
Reviewed By: jhenderson, Higuoxing
Differential Revision: https://reviews.llvm.org/D82274
Reorder `DumpSection` under `handleArgs` in file `ELFObjcopy.cpp`.
`DumpSection` is placed before `replaceAndRemoveSections` and is
therefore now the first operation under `handleArgs`. Thus, it is now
performed before both `add` and `remove` section operations.
Change for the MachO format at D81123. Together fixes https://bugs.llvm.org/show_bug.cgi?id=44283.
Reviewed By: alexshap, jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D81097
When a group member is removed, the corresponding record in the
SHT_GROUP section has to be deleted.
This fixes PR46064.
Differential Revision: https://reviews.llvm.org/D80568
When a SHT_GROUP section is removed, but other sections of the group are
kept, the SHF_GROUP flag of these sections should be dropped, otherwise
the resulting ELF file will be malformed.
Differential Revision: https://reviews.llvm.org/D80511
cctools strip has the option "-T" which removes Swift symbols.
This diff implements this option in llvm-strip for MachO.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D80099
To avoid undefined behavior caught by -fsanitize=undefined on binary-paddr.test
void SectionWriter::visit(const Section &Sec) {
if (Sec.Type != SHT_NOBITS)
// Sec.Contents is empty while Sec.Offset may be out of bound
llvm::copy(Sec.Contents, Out.getBufferStart() + Sec.Offset);
}
After SHF_ALLOC sections are ordered by LMA:
* If initial sections are empty, GNU objcopy skips their contents while we
emit leading zeros. (binary-paddr.test %t4)
* If trailing sections are empty, GNU objcopy skips their contents while we
emit trailing zeros. (binary-paddr.test %t5)
This patch matches GNU objcopy's behavior. Linkers don't keep p_memsz
PT_LOAD segments. Such empty sections would not have a containing
PT_LOAD and `Section::ParentSegment` might be null if linkers fail to
optimize the file offsets (lld D79254).
In particular, without D79254, the arm Linux kernel's multi_v5_defconfig
depends on this behavior: in `vmlinux`, an empty .text_itcm is mapped at
a very high address (0xfffe0000) but the kernel does not expect
`objcopy -O binary` to create a very large `arch/arm/boot/Image`
(0xfffe0000-0xc0000000 ~= 1GiB). See https://bugs.llvm.org/show_bug.cgi?id=45632
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D79229
Don't error on Config.KeepFileSymbols for COFF and Mach-O.
Original description:
GNU objcopy removes STT_FILE symbols for strip-debug operations, and
keeps them for --discard-all operation. Match their behaviour for
llvm-objcopy.
Bug: https://github.com/android/ndk/issues/1212
Differential Revision: https://reviews.llvm.org/D76675
It can be used to avoid passing the begin and end of a range.
This makes the code shorter and it is consistent with another
wrappers we already have.
Differential revision: https://reviews.llvm.org/D78016
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
.text sh_address=0x1000 sh_offset=0x1000
.data sh_address=0x3000 sh_offset=0x2000
In an objcopy -O binary output, the distance between two sections equal
their LMA differences (0x3000-0x1000), instead of their sh_offset
differences (0x2000-0x1000). This patch changes our behavior to match
GNU.
This rule gets more complex when the containing PT_LOAD has
p_vaddr!=p_paddr. GNU objcopy essentially computes
sh_offset-p_offset+p_paddr for each candidate section, and removes the
gap before the first address.
Added tests to binary-paddr.test to catch the compatibility problem.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D71035
--only-keep-debug produces a debug file as the output that only
preserves contents of sections useful for debugging purposes (the
binutils implementation preserves SHT_NOTE and non-SHF_ALLOC sections),
by changing their section types to SHT_NOBITS and rewritting file
offsets.
See https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
The intended use case is:
```
llvm-objcopy --only-keep-debug a a.dbg
llvm-objcopy --strip-debug a b
llvm-objcopy --add-gnu-debuglink=a.dbg b
```
The current layout algorithm is incapable of deleting contents and
shrinking segments, so it is not suitable for implementing the
functionality.
This patch adds a new algorithm which assigns sh_offset to sections
first, then modifies p_offset/p_filesz of program headers. It bears a
resemblance to lld/ELF/Writer.cpp.
Reviewed By: jhenderson, jakehehrlich
Differential Revision: https://reviews.llvm.org/D67137
`llvm::objcopy:🧝:*Section::classof` matches Type and Flags, yet Type
and Flags are mutable (by setSectionFlagsAndTypes and upcoming
--only-keep-debug feature). Add OriginalType & OriginalFlags to be used
in classof, to prevent classof results from changing.
Reviewed By: jakehehrlich, jhenderson, alexshap
Differential Revision: https://reviews.llvm.org/D69739
* Improve comments.
* Reorder the assignment to Obj.SectionNames before the symbol table
creation code. Add a test.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D69526
This works around a bug in Debian's patchset for glibc. The bug is
described in detail in the upstream debian bug:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943798, but the short
version of it is that glibc on any Debian based distro don't load
libraries unless it has a .ARM.attribute section.
Reviewed by: jhenderson, rupprecht, MaskRay, jakehehrlich
Differential Revision: https://reviews.llvm.org/D69188
Patch by Tobias Hieta.
It was revealed by D69260.
Tool crashed when scanned relocations in a object without a symbol table.
This patch teaches it either to handle such objects (when relocations
does not use symbols we do not need a symbol table to proceed)
or to show an appropriate error otherwise.
Differential revision: https://reviews.llvm.org/D69304
Exposed by D69041. If SHT_SYMTAB does not exist, ELFObjcopy.cpp:handleArgs will crash due
to a null pointer dereference.
for (const NewSymbolInfo &SI : Config.ELF->SymbolsToAdd) {
...
Obj.SymbolTable->addSymbol(
Fix this by creating .symtab and .strtab on demand in ELFBuilder<ELFT>::readSections,
if --add-symbol is specified.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D69093
llvm-svn: 375105
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
GNU objcopy documents that -B is only useful with architecture-less
input (i.e. "binary" or "ihex"). After D67144, -O defaults to -I, and
-B is essentially a NOP.
* If -O is binary/ihex, GNU objcopy ignores -B.
* If -O is elf*, -B provides the e_machine field in GNU objcopy.
So to convert a blob to an ELF, `-I binary -B i386:x86-64 -O elf64-x86-64` has to be specified.
`-I binary -B i386:x86-64 -O elf64-x86-64` creates an ELF with its
e_machine field set to EM_NONE in GNU objcopy, but a regular x86_64 ELF
in elftoolchain elfcopy. Follow the elftoolchain approach (ignoring -B)
to simplify code. Users that expect their command line portable should
specify -B.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D67215
llvm-svn: 371914
Handle --prefix-alloc-sections after --rename-sections so that --prefix-alloc-sections code
does not have to check if renaming has been performed.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D66931
llvm-svn: 371591
"Section" can refer to the type llvm::objcopy:🧝:Section or the
variable name. Rename it to "Sec" for clarity. "Sec" is already used a
lot, so this change improves consistency as well.
Also change `auto` to `const SectionBase` for readability.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67143
llvm-svn: 370852
Summary:
GNU --strip-unneeded strips debugging sections as well. Do that for llvm-objcopy as well.
Additionally, add a test that verifies we keep the .gnu_debuglink section. This apparently was not always the case, and I'm not sure which commit fixed it, but there doesn't appear to be any test coverage to make sure we continue to do so.
This fixes PR41043.
Reviewers: jhenderson, jakehehrlich, espindola, alexshap
Subscribers: emaste, arichardson, MaskRay, abrachet, seiya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66623
llvm-svn: 369761
Summary:
The matchers for section/symbol related flags (e.g. `--keep-symbol=Name` or `--regex --keep-symbol=foo.*`) are currently just vectors that are matched linearlly. However, adding wildcard support would require negative matching too, e.g. a symbol should be removed if it matches a wildcard *but* doesn't match some other wildcard.
To make the next patch simpler, consolidate matching logic to a class defined in CopyConfig that takes care of matching.
Reviewers: jhenderson, seiya, MaskRay, espindola, alexshap
Reviewed By: jhenderson, MaskRay
Subscribers: emaste, arichardson, jakehehrlich, abrachet, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66432
llvm-svn: 369689
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
This reverts r365193 (git commit 194f16b354)
This patch doesn't work with binaries built w/ `--emit-relocs`, e.g.
```
$ echo 'int main() { return 0; }' | clang -Wl,--emit-relocs -x c - -o foo && llvm-objcopy --strip-unneeded foo
llvm-objcopy: error: 'foo': not stripping symbol '__gmon_start__' because it is named in a relocation
```
llvm-svn: 365712
Georgy Komarov