201 Commits

Author SHA1 Message Date
Fangrui Song
c465429f28 [llvm-objcopy] Delete --build-id-link-{dir,input,output}
The few options are niche. They solved a problem which was traditionally solved
with more shell commands (`llvm-readelf -n` fetches the Build ID. Then
`ln` is used to hard link the file to a directory derived from the Build ID.)

Due to limitation, they are no longer used by Fuchsia and they don't appear to
be used elsewhere (checked with Google Search and Debian Code Search). So delete
them without a transition period.

Announcement: https://lists.llvm.org/pipermail/llvm-dev/2021-February/148446.html

Differential Revision: https://reviews.llvm.org/D96310
2021-02-15 11:17:32 -08:00
Fangrui Song
3e837e1735 [llvm-objcopy][test] Stablize build-id-link-dir.test 2021-02-08 17:22:22 -08:00
Patrick Oppenlander
93345e825a [llvm-objcopy] -O binary: consider SHT_NOBITS sections to be empty
This is consistent with BFD objcopy.

Previously llvm objcopy would allocate space for SHT_NOBITS sections
often resulting in enormous binary files.

New test case (binary-paddr.test %t6).

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D95569
2021-02-01 15:01:25 -08:00
Abhina Sreeskantharajan
42a21778f6 [test] Use host platform specific error message substitution in lit tests
On z/OS, the following error message is not matched correctly in lit tests.

```
EDC5129I No such file or directory.
```

This patch uses a lit config substitution to check for platform specific error messages.

Reviewed By: muiez, jhenderson

Differential Revision: https://reviews.llvm.org/D95246
2021-01-29 07:16:30 -05:00
Georgii Rymar
d5e48f1347 [yaml2obj][obj2yaml] - Improve how we set/dump the sh_entsize field.
We already set the `sh_entsize` field in a single place
for all non-implicit sections.

This patch reorders the logic slightly and with it
we finally have the only one place where the `sh_entsize` is set.

obj2yaml will not dump the `EntSize` key for `SHT_DYNSYM/SHT_SYMTAB` sections anymore,
when the value of `sh_entsize` is equal to `sizeof(Elf_Sym)`

Note that this also seems revealed an issue in llvm-objcopy:
Previously yaml2obj set the `sh_entsize` for the `.symtab` section to 0x18,
now we it sets it for `SHT_SYMTAB` sections, i.e. by type.
But the `llvm-objcopy/ELF/only-keep-debug.test` has a `.symtab` section of type `SHT_STRTAB`,
and now yaml2obj sets the `sh_entsize` to 0 for it.
I had to update the corresponding check lines for `ES`, but the behavior of
`llvm-objcopy` should be fixed instead I think.
I've added a TODO and a comment.

Differential revision: https://reviews.llvm.org/D95364
2021-01-26 13:33:02 +03:00
Abhina Sreeskantharajan
978444d531 Revert "[SystemZ][z/OS] Fix No such file or directory expression error"
This reverts commit 06f8a49693957bc27b83e0ab5f429ff874941a07.
2021-01-25 08:29:38 -05:00
Abhina Sreeskantharajan
689aaba7ac [SystemZ][z/OS] Fix No such file or directory expression error matching in lit tests
On z/OS, the following error message is not matched correctly in lit tests. This patch updates the CHECK expression to match successfully.
```
EDC5129I No such file or directory.
```

Reviewed By: muiez

Differential Revision: https://reviews.llvm.org/D94239
2021-01-18 07:14:37 -05:00
Brandon Bergren
696bd3073f [PowerPC] Support powerpcle target in LLVMObject [2/5]
Add object file handling for powerpcle-*-*.

Adjust tests.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D93916
2021-01-02 12:17:39 -06:00
Georgii Rymar
98a4289810 [llvm-readobj] - For SHT_REL relocations, don't display an addend.
This is https://bugs.llvm.org/show_bug.cgi?id=44257.

In LLVM style we always print `0` as addend when dumping
SHT_REL relocations. It is confusing, this patch stops
printing it as the first comment on the bug page suggests.

Differential revision: https://reviews.llvm.org/D93033
2020-12-14 12:03:00 +03:00
Fangrui Song
20de182246 [llvm-objcopy] --only-keep-debug: place zero-size segment according to its parent segment
Alternative to D74755. sectionWithinSegment() treats an empty section as having
a size of 1. Due to the rule, an empty .tdata will not be attributed to an
empty PT_TLS. (The empty p_align=64 PT_TLS is for Android Bionic's TCB
compatibility (ELF-TLS). See https://reviews.llvm.org/D62055#1507426)

Currently --only-keep-debug will not layout a segment with no section
(layoutSegmentsForOnlyKeepDebug()), thus p_offset of PT_TLS can go past the end
of the file. The strange p_offset can trigger validation errors for subsequent
tools, e.g. llvm-objcopy errors when reading back the separate debug file
(readProgramHeaders()).

This patch places such an empty segment according to its parent segment.  This
special cases works for the empty PT_TLS used in Android. For a non-empty
segment, it should have at least one non-empty section and will be handled by
the normal code. Note, p_memsz PT_LOAD is rejected by both Linux and FreeBSD.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D90897
2020-11-11 09:21:10 -08:00
Georgii Rymar
a7a447be0f [yaml2obj] - ProgramHeaders: introduce FirstSec/LastSec instead of Sections list.
Imagine we have a YAML declaration of few sections: `foo1`, `<unnamed 2>`, `foo3`, `foo4`.

To put them into segment we can do (1*):

```
Sections:
 - Section: foo1
 - Section: foo4
```

or we can use (2*):

```
Sections:
 - Section: foo1
 - Section: foo3
 - Section: foo4
```

or (3*) :

```
Sections:
 - Section: foo1
## "(index 2)" here is a name that we automatically created for a unnamed section.
 - Section: (index 2)
 - Section: foo3
 - Section: foo4
```

It looks really confusing that we don't have to list all of sections.

At first I've tried to make this rule stricter and report an error when there is a gap
(i.e. when a section is included into segment, but not listed explicitly).
This did not work perfect, because such approach conflicts with unnamed sections/fills (see (3*)).

This patch drops "Sections" key and introduces 2 keys instead: `FirstSec` and `LastSec`.
Both are optional.

Differential revision: https://reviews.llvm.org/D90458
2020-11-09 13:00:50 +03:00
Fangrui Song
ee142c4988 [llvm-objcopy] Make --set-section-flags work with --add-section
This matches behavior GNU objcopy and can simplify clang-offload-bundler
(which currently works around the issue by invoking llvm-objcopy twice).

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D90438
2020-11-04 09:39:14 -08:00
Georgii Rymar
d4035af253 [llvm-readelf/obj] - Print section symbol names properly when dumping relocations.
Currently `--relocations` ignores section symbol names and always prints
section names for them. This is inconsistent with GNU readelf and with `--symbols`.

We have a code in `getFullSymbolName` (which is used for `--symbols`) which can be
reused for `getRelocationTarget` (used for `--relocations`).
With that the issue described is fixed and code becomes a bit shorter.
Also with this change we start to print more relocations (in situations when we just
showed warnings instead before) and also start to report more diagnostic warnings
(see reloc-zero-name-or-value.test).

Differential revision: https://reviews.llvm.org/D87613
2020-09-23 13:25:39 +03:00
Alexander Shaposhnikov
10af5bad44 [llvm-objcopy] Consolidate and unify version tests
In this diff the tests which verify version printing functionality are refactored.
Since they are not specific to a particular format we move them into tool-version.test
and slightly unify (similarly to tool-name.test and tool-help-message.test).

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D87211
2020-09-07 18:44:32 -07:00
Alexandre Ganea
a680ea2c72 Fix "last accessed time" test failing on Windows
Before this patch, the tests in llvm/test/tools/llvm-objcopy/ELF/strip-preserve-atime.test used to fail on my machine, because the "last accessed time" is disabled in the OS by default since Windows XP. One needs to explicitly enable it for the feature to work. Otherwise the last access time is the last write time. Please see: https://superuser.com/questions/251263/the-last-access-date-is-not-changed-even-after-reading-the-file-on-windows-7

    Differential Revision: https://reviews.llvm.org/D85669
2020-08-10 16:03:14 -04:00
Fangrui Song
dd405f1a53 Revert D83834 "Add test utility 'extract'"
This reverts commit d054c7ee2e9f4f98af7f22a5b00a941eb919bd59.

There are discussions about the utility name, its functionality and user interface.
Revert before we reach consensus.
2020-07-28 13:26:33 -07:00
Fangrui Song
d054c7ee2e Add test utility 'extract'
See https://lists.llvm.org/pipermail/llvm-dev/2020-July/143373.html
"[llvm-dev] Multiple documents in one test file" for some discussions.

`extract part filename` splits the input file into multiple parts separated by
regex `^(.|//)--- ` and extract the specified part to stdout or the
output file (if specified).

Use case A (organizing input of different formats (e.g. linker
script+assembly) in one file).

```
// RUN: extract lds %s -o %t.lds
// RUN: extract asm %s -o %t.s
// RUN: llvm-mc %t.s -o %t.o
// RUN: ld.lld -T %t.lds %t.o -o %t
This is sometimes better than the %S/Inputs/ approach because the user
can see the auxiliary files immediately and don't have to open another file.
```

Use case B (for utilities which don't have built-in input splitting
feature):

```
// RUN: extract case1 %s | llc | FileCheck %s --check-prefix=CASE1
// RUN: extract case2 %s | llc | FileCheck %s --check-prefix=CASE2
Combing tests prudently can improve readability.
This is sometimes better than having multiple test files.
```

Since this is a new utility, there is no git history concerns for
UpperCase variable names. I use lowerCase variable names like mlir/lld.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83834
2020-07-23 19:15:35 -07:00
Georgy Komarov
afd81a637d
[llvm-objcopy] Fix crash when removing symbol table at same time as adding a symbol
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
2020-07-05 05:14:00 +03:00
Georgy Komarov
e503851d80 [llvm-objcopy] Emit error if removing symtab referenced by group section
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
2020-06-29 10:42:03 +01:00
Sid Manning
e5911de377 [Hexagon][llvm-objcopy] Add missing check for SHN_HEXAGON_SCOMMON_1
Differential Revision: https://reviews.llvm.org/D82484
2020-06-24 19:56:01 -05:00
Alexander Shaposhnikov
395920a614 [llvm-objcopy] Update help message tests
This diff merges help message tests for llvm-objcopy, llvm-strip and
llvm-install-name-tool.

Patch by Sameer Arora!

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D82012
2020-06-24 12:40:31 -07:00
Alexander Shaposhnikov
ca133cdecf [llvm-objcopy] Update help messages
This diff updates the help messages for llvm-objcopy, llvm-strip and
llvm-install-name-tool.

Patch by Sameer Arora!

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D81907
2020-06-24 11:19:56 -07:00
Georgii Rymar
818ab3d654 [yaml2obj] - Allocate the file space for SHT_NOBITS sections in some cases.
This teaches yaml2obj to allocate file space for a no-bits section
when there is a non-nobits section in the same segment that follows it.

It was discussed in D78005 thread and matches GNU linkers and LLD behavior.

Differential revision: https://reviews.llvm.org/D80629
2020-06-11 12:54:53 +03:00
Sameer Arora
a018b538a6 [llvm-objcopy] Reorder --dump-section before --remove-section for ELF
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
2020-06-05 10:45:51 -07:00
Georgii Rymar
5750f12b82 Revert "[yaml2obj] - Allocate the file space for SHT_NOBITS sections in some cases."
This reverts commit aa3a85cdaa4432ca389bdbf48049eaa64dc6e266.

There are problems with it. See here: https://reviews.llvm.org/D80629
2020-06-04 13:17:48 +03:00
Georgii Rymar
aa3a85cdaa [yaml2obj] - Allocate the file space for SHT_NOBITS sections in some cases.
This teaches yaml2obj to allocate file space for a no-bits section
when there is a non-nobits section in the same segment that follows it.

It was discussed in D78005 thread and matches GNU linkers and LLD behavior.

Differential revision: https://reviews.llvm.org/D80629
2020-06-02 17:19:24 +03:00
Igor Kudrin
5b875bf59b [llvm-objcopy][ELF] Fix removing a group member.
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
2020-05-29 20:24:53 +07:00
Igor Kudrin
a9313282cd [llvm-objcopy][ELF] Fix removing SHT_GROUP sections.
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
2020-05-29 20:24:53 +07:00
Georgii Rymar
e2b134b01a [yaml2obj] - Stop using square brackets for unique suffixes.
For describing section/symbol names we can use unique suffixes,
e.g:

```
- Name: '.foo [1]`
- Name: '.foo [2]`
```

It can be a problem (see https://reviews.llvm.org/D79984#inline-734829),
because `[]` are sometimes used to describe a macros:

```
- Name: "[[a0]]"
```

Seems the better approach is to use something else, like "()".
This patch does it and refactors the code related.

Differential revision: https://reviews.llvm.org/D80123
2020-05-19 12:59:13 +03:00
Fangrui Song
32b19334da [llvm-objcopy][ELF] Allow --dump-section to dump an empty non-SHT_NOBITS section
This is the ELF part of D75949.

GNU objcopy from binutils 2.35 onwards will support an empty non-SHT_NOBITS section as
well
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=e052e2ba295a65b6ea80cbc3f90495beca299c42

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D79339
2020-05-05 08:26:34 -07:00
Fangrui Song
a11e90a6b9 [llvm-objcopy][test] ELF/dump-section.test: change #CHECK to # CHECK
The latter is more common and thus the preferred way to use CHECK lines.
2020-05-05 08:26:34 -07:00
Fangrui Song
ec786906f5 [llvm-objcopy] -O binary: skip empty sections
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
2020-05-01 14:25:37 -07:00
Fangrui Song
fd624e623d [llvm-objcopy] Don't specialize the all zero p_paddr case
Spotted by https://reviews.llvm.org/D74755#1998673

> it looks like OrderedSegments in the function is only used to set the physical address to the virtual address when there are no physical addresses set amongst these sections.

I believe this behavior was copied from https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=6ffd79000b45e77b3625143932ffbf781b6aecab (2008-05)
The commit was made for some corner cases of very old linkers.
This special rule does not seem useful and remove it can allow us to
delete a large chunk of code.

Reviewed By: jhenderson, jakehehrlich

Differential Revision: https://reviews.llvm.org/D78786
2020-04-27 11:20:41 -07:00
Georgii Rymar
2bf5674317 [yaml2obj] - Program headers: add an additional check for Offset
The `Offset` field is used to set the file offset of a program header.
In a normal object it should not be greater than the minimal offset
of sections included into segment.

This patch adds a check for that and adds tests.

Differential revision: https://reviews.llvm.org/D78304
2020-04-22 12:49:05 +03:00
Fangrui Song
b14e9e3c0c Reland D76675 [llvm-objcopy] Match GNU behaviour regarding file symbols
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
2020-04-20 21:18:48 -07:00
Yi Kong
37a1c2eda5 Revert "[llvm-objcopy] Match GNU behaviour regarding file symbols"
This reverts commit 7c65e88d0bc85ff2732a4e23c397ff842b97b828.

Broke non ELF targets.
2020-04-21 12:04:01 +08:00
Yi Kong
7c65e88d0b [llvm-objcopy] Match GNU behaviour regarding file symbols
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
2020-04-21 11:30:04 +08:00
Bill Wendling
edcfc391e1 [Object] Use BFD name for little-endian PowerPC64
Summary:
Little-endian PowerPC object files should report "elf64-powerpcle" instead of
"elf64-powerpc".

Reviewers: jhenderson, MaskRay, espindola, alexshap, rupprecht, #powerpc

Reviewed By: MaskRay

Subscribers: wuzish, emaste, nemanjai, shchenz, steven.zhang, llvm-commits

Tags: #llvm, #powerpc

Differential Revision: https://reviews.llvm.org/D78344
2020-04-19 20:10:05 -07:00
Georgii Rymar
b6d77e792c [tools][tests] - Use --check-prefixes instead of multiple --check-prefix. NFCI.
There is no need to use `--check-prefix` multiple times.
It helps to improve readability/test maintainability.
This patch does it for all tools at once.

Differential revision: https://reviews.llvm.org/D78217
2020-04-17 12:35:25 +03:00
Georgii Rymar
82bfe3b177 [LLVM/tools][test] - Remove/fix dead check prefixes.
We have a few unused/broken FileCheck prefixes in `llvm/test/tools`.
This patch fixes it.

Differential revision: https://reviews.llvm.org/D78110
2020-04-15 13:09:51 +03:00
Sid Manning
5002863ab0 Support bfdname "elf32-hexagon".
Add support and update testcases.

Differential Revision: https://reviews.llvm.org/D77579
2020-04-06 17:22:56 -05:00
James Henderson
ccf16c4d38 Make test more robust
llvm-readobj prints the file path as part of the output, so
--implicit-check-not patterns can accidentally match it. This patch
makes the test more robust by preventing failures if "foo" is in
somebody's path.

Reviewed by: grimar

Differential Revision: https://reviews.llvm.org/D77546
2020-04-06 14:47:05 +01:00
Vedant Kumar
5e6e545cba [test] Re-enable accidentally disabled X86 tests
A number of X86 tests were accidentally disabled in
https://reviews.llvm.org/D73568. This commit re-enables those tests.

```
$ for x86_test in $(gg 'REQUIRES: x86$' llvm/test | fst); do sed -i "" '/REQUIRES: x86/d' $x86_test; done
```

(Note that 'x86' is not an available feature, that's what caused the
tests to be disabled.)
2020-03-19 09:29:23 -07:00
Fangrui Song
536ba6373f [Object] Change ELFObjectFile<ELFT>::getFileFormatName() to use BFD names
Follow-up for D74433

What the function returns are almost standard BFD names, except that "ELF" is
in uppercase instead of lowercase.

This patch changes "ELF" to "elf" and changes ARM/AArch64 to use their BFD names.
MIPS and PPC64 have endianness differences as well, but this patch does not intend to address them.

Advantages:

* llvm-objdump: the "file format " line matches GNU objdump on ARM/AArch64 objects
* "file format " line can be extracted and fed into llvm-objcopy -O literally.
  (https://github.com/ClangBuiltLinux/linux/issues/779 has such a use case)

Affected tools: llvm-readobj, llvm-objdump, llvm-dwarfdump, MCJIT (internal implementation detail, not exposed)

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D76046
2020-03-16 07:42:04 -07:00
Georgii Rymar
b236b4cb43 [yaml2obj] - Set a default value for PAddr property of a program header to a value of VAddr
`PAddr` corresponds to `p_paddr` of a program header, which is the segment's physical
address for systems in which physical addressing is relevant. `p_paddr` is often equal
to `p_vaddr`, which is the virtual address of a segment.

This patch changes the default for `PAddr` from 0 to a value of `VAddr`.

Differential revision: https://reviews.llvm.org/D76131
2020-03-14 17:44:57 +03:00
Jordan Rupprecht
c140810ea1 [llvm-readobj] Include section name of notes.
This changes the output of `llvm-readelf -n` from:

```
Displaying notes found at file offset 0x<...> with length 0x<...>:
```

to:

```
Displaying notes found in: .note.foo
```

And similarly, adds a `Name:` field to the `llvm-readobj -n` output for notes.

This change not only increases GNU compatibility, it also makes it much easier to read notes. Note that we still fall back to printing the file offset/length in cases where we don't have a section name, such as when printing notes in program headers or printing notes in a partially stripped file (GNU readelf does the same).

Fixes llvm.org/PR41339.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D75647
2020-03-05 09:53:14 -08:00
Fangrui Song
9e1319df7e [llvm-readelf] Make --all output order closer to GNU readelf
https://bugs.llvm.org/show_bug.cgi?id=43403

The new order makes it easy to compare the two tools' --all.

Reviewed By: grimar, rupprecht

Differential Revision: https://reviews.llvm.org/D75592
2020-03-04 12:22:12 -08:00
Fangrui Song
6503aadcc6 [llvm-objcopy][test] Improve empty section tests
empty-sections.test: add two tests adapted from @jhenderson's https://reviews.llvm.org/D74755#1882221
strip-non-alloc.test: improve. D74755 will change the attribution of an empty section.

They mostly test the behavior of Object.cpp:sectionWithinSegment : how we attribute sections to segments.
`ParentSegment` can affect some subtle layout decisions.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D74879
2020-02-26 08:57:23 -08:00
Georgii Rymar
31f2ad9c36 [yaml2obj] - Automatically assign sh_addr for allocatable sections.
I've noticed that it is not convenient to create YAMLs from
binaries (using obj2yaml) that have to be test cases for obj2yaml
later (after applying yaml2obj).

The problem, for example is that obj2yaml emits "DynamicSymbols:"
key instead of .dynsym. It also does not create .dynstr.
And when a YAML document without explicitly defined .dynsym/.dynstr
is given to yaml2obj, we have issues:

1) These sections are placed after non-allocatable sections (I've fixed it in D74756).
2) They have VA == 0. User needs create descriptions for such sections explicitly manually
    to set a VA.

This patch addresses (2). I suggest to let yaml2obj assign virtual addresses by itself.
It makes an output binary to be much closer to "normal" ELF.
(It is still possible to use "Address: 0x0" for a section to get the original behavior
if it is needed)

Differential revision: https://reviews.llvm.org/D74764
2020-02-22 14:43:54 +03:00
Georgii Rymar
3439d4ee0e [yaml2obj] - Change the order of implicitly created sections.
.dynsym and .dynstr are allocatable and therefore normally are placed
before non-allocatable .strtab, .shstrtab, .symtab sections.
But we are placing them after currently what creates a mix of
alloc/non-alloc sections and does not look normal.

Differential revision: https://reviews.llvm.org/D74756
2020-02-19 15:09:19 +03:00