Commit Graph

12021 Commits

Author SHA1 Message Date
Georgii Rymar
41a5636b6f [llvm-readobj] - Remove Error.cpp,.h and drop dependencies in the code.
We have Error.cpp/.h which contains some code for working with error codes.
In fact we use Error/Expected<> almost everywhere already and we can get rid
of these files.

Note: a few places in the code used readobj specific error codes,
e.g. `return readobj_error::unknown_symbol`. But these codes are never really used,
i.e. the code checks the fact of a success/error call only.
So I've changes them to `return inconvertibleErrorCode()` for now.
It seems that these places probably should be converted to use `Error`/`Expected<>`.

Differential revision: https://reviews.llvm.org/D86772
2020-09-01 16:46:17 +03:00
Georgii Rymar
522d076ef9 [llvm-readobj/elf] - Report warnings instead of errors when dumping broken stack sizes sections.
This replaces `reportError` calls with `reportUniqueWarning` and improves testing
for the code that is related to stack sizes dumping.

Differential revision: https://reviews.llvm.org/D86783
2020-09-01 13:46:54 +03:00
Xing GUO
45321f3e73 [DWARFYAML] Make the debug_str section optional.
This patch makes the debug_str section optional. When the debug_str
section exists but doesn't contain anything, yaml2obj will emit a
section header for it.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D86860
2020-09-01 10:02:09 +08:00
Christopher Tetreault
b93c073189 [SVE] Remove calls to VectorType::getNumElements() from llvm-stress
Differential Revision: https://reviews.llvm.org/D86898
2020-08-31 15:51:15 -07:00
Florian Hahn
102583c8b4 [llvm-reduce] Create returns with undef values for non-void functions.
Currently replaceBranchTerminator/removeUninterestingBBsFromSwitch
always creates `ret void` instructions if no successor is in the chunk.

This results in invalid IR for functions with non-void return types,
which makes those reductions unfeasible. Instead, create `ret ty undef`
for functions with non-void return types.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D86849
2020-08-31 16:33:46 +01:00
Georgii Rymar
e56dc2e569 [llvm-readobj/elf] - Don't fail when dumping an archive with a member that can't be recognized.
Imagine we have an archive that has 3 objects in the following order:
<valid known object>,<unknown object> and <valid known object>.

Currently llvm-readelf/obj report an error and stops dumping in the middle.
This patch changes the error reported to warning.

Differential revision: https://reviews.llvm.org/D86771
2020-08-31 13:16:15 +03:00
Tyker
b04be3c048 [llvm-reduce] Function body reduction: don't forget to unset comdat
althought the interstingness test should usually fail when the module is invalid
this changes reduces the frequency at which llvm-reduce generate invalid IR.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D86404
2020-08-30 12:17:33 +02:00
Georgii Rymar
56c55fadc1 [llvm-readobj] - Simplify the code that creates dumpers. NFCI.
We have a few helper functions like the following:
```
std::error_code create*Dumper(...)
```

In fact we do not need or want to use `std::error_code` and the code
can be simpler if we just return `std::unique_ptr<ObjDumper>`.

This patch does this change and refines the signature of `createDumper`
as well.

Differential revision: https://reviews.llvm.org/D86718
2020-08-28 11:36:10 +03:00
Florian Hahn
4cf9e27313 [llvm-reduce] Skip chunks that lead to broken modules.
Some reduction passes may create invalid IR. I am not aware of any use
case where we would like to proceed reducing invalid IR. Various utils
used here, including CloneModule, assume the module to clone is valid
and crash otherwise.

Ideally, no reduction pass would create invalid IR, but some currently
do. ReduceInstructions can be fixed relatively easily (D86210), but
others are harder. For example, ReduceBasicBlocks may remove result in
invalid PHI nodes.

For now, skip the chunks. If we get to the point where all reduction
passes result in valid IR, we may want to turn this into an assertion.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D86212
2020-08-28 09:08:35 +01:00
Russell Gallop
16726ba1da [Test] Tidy up loose ends from LLVM_HAS_GLOBAL_ISEL
This hasn't been allowed as a build option since r309990

Remove leftover REQUIRES: global-isel

Differential Revision: https://reviews.llvm.org/D86714
2020-08-27 16:36:27 +01:00
Alexandre Ganea
1c64f56c35 [Support] On Windows, add optional support for {rpmalloc|snmalloc|mimalloc}
This patch optionally replaces the CRT allocator (i.e., malloc and free) with rpmalloc (mixed public domain licence/MIT licence) or snmalloc (MIT licence) or mimalloc (MIT licence). Please note that the source code for these allocators must be available outside of LLVM's tree.

To enable, use `cmake ... -DLLVM_INTEGRATED_CRT_ALLOC=D:/git/rpmalloc -DLLVM_USE_CRT_RELEASE=MT` where `D:/git/rpmalloc` has already been git clone'd from `https://github.com/mjansson/rpmalloc`. The same applies to snmalloc and mimalloc.

When enabled, the allocator will be embeded (statically linked) into the LLVM tools & libraries. This currently only works with the static CRT (/MT), although using the dynamic CRT (/MD) could potentially work as well in the future.

When enabled, this changes the memory stack from:
  new/delete -> MS VC++ CRT malloc/free -> HeapAlloc -> VirtualAlloc
to:
  new/delete -> {rpmalloc|snmalloc|mimalloc} -> VirtualAlloc

The goal of this patch is to bypass the application's global heap - which is thread-safe thus inducing locking - and instead take advantage of a modern lock-free, thread cache, allocator. On a 6-core Xeon Skylake we observe a 2.5x decrease in execution time when linking a large scale application with LLD and ThinLTO (12 min 20 sec -> 5 min 34 sec), when all hardware threads are being used (using LLD's flag /opt:lldltojobs=all). On a dual 36-core Xeon Skylake with all hardware threads used, we observe a 24x decrease in execution time (1 h 2 min -> 2 min 38 sec) when linking a large application with LLD and ThinLTO. Clang build times also see a decrease in the range 5-10% depending on the configuration.

Differential Revision: https://reviews.llvm.org/D71786
2020-08-27 11:09:46 -04:00
Lang Hames
02bae0a8ff [ORC][JITLink] Switch to unique ownership for EHFrameRegistrars.
This will make stateful registrars (e.g. a future TargetProcessControl based
registrar) easier to deal with.
2020-08-26 16:59:45 -07:00
Steven Wu
0298cbfe6d [LTO] Don't apply LTOPostLink module flag during writeMergedModule
For `ld64` which uses legacy LTOCodeGenerator, it relies on
writeMergedModule to perform `ld -r` (generates a linked object file).
If all the inputs to `ld -r` is fullLTO bitcode, `ld64` will linked the
bitcode module, internalize all the symbols and write out another
fullLTO bitcode object file. This bitcode file doesn't have all the
bitcode inputs and it should not have LTOPostLink module flag. It will
also cause error when this bitcode object file is linked with other LTO
object file.
Fix the issue by not applying LTOPostLink flag during writeMergedModule
function. The flag should only be added when all the bitcode are linked
and ready to be optimized.

rdar://problem/58462798

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D84789
2020-08-26 11:17:45 -07:00
Xing GUO
d25b99b1d8 [DWARFYAML] Make the unit_length and header_length fields optional.
This patch makes the unit_length and header_length fields of line tables
optional. yaml2obj is able to infer them for us.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86590
2020-08-26 20:35:10 +08:00
Georgii Rymar
3916410662 [llvm-readobj/elf][test] - Add testing for EM_* specific OS/ABI values.
We have no tests for OS/ABI values specific to
EM_TI_C6000, ELFOSABI_AMDGPU_MESA3D and ELFOSABI_ARM machines.

Also, related arrays in the code are not grouped together.
(That is why such testing was missed I guess).

The patch fixes that all.

Differential revision: https://reviews.llvm.org/D86341
2020-08-26 14:41:16 +03:00
Georgii Rymar
fbecfa6986 [obj2yaml] - Cleanup error reporting (remove Error.cpp/.h files)
This removes Error.cpp/.h files from obj2yaml.
These files are not needed because we are
using `Error`s instead of error codes widely and do
not need a logic related to obj2yaml specific
error codes anymore.

I had to adjust just a few lines of tool's code
to remove remaining dependencies.

Differential revision: https://reviews.llvm.org/D86536
2020-08-26 14:25:11 +03:00
Georgii Rymar
691f3730a9 [llvm-readobj] - Don`t crash when --section-symbols is requested for an object w/o .symtab.
llvm-readobj crashes when `-S --section-symbols` is used
on an object that has no symbol table.

The patch fixes it.

Differential revision: https://reviews.llvm.org/D86520
2020-08-26 14:13:05 +03:00
Martin Storsjö
61ac2a0eea [llvm-readobj] Fix arm64 unwind opcode disassembly printing
Add a missing minus, fix vertical alignment of instructions for one opcode.

Differential Revision: https://reviews.llvm.org/D86523
2020-08-26 09:38:11 +03:00
Adrien Guinet
add1ee3a12 [llvm-lipo] Add support for bitcode files
A Mach-O universal binary may contain bitcode as a slice.
This diff adds proper handling of such binaries to llvm-lipo.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D85740
2020-08-25 21:11:18 -07:00
Wolfgang Pieb
e13b33f132 [llvm-mca][NFC] Refactor handling of views that examine individual instructions,
including printing them.

Reviewers: andreadb, lebedev.ri

Differential Review: https://reviews.llvm.org/D86390

Introduces a new base class "InstructionView" that such views derive from.
Other views still use the "View" base class.
2020-08-25 12:12:37 -07:00
Georgii Rymar
f23c466d76 [llvm-readobj] - Print "Unknown" when a program header is unknown.
Currently, when a program header type is unknown, we dont print anything:

```
ProgramHeader {
  Type:  (0x60000000)
```

With this patch the output will be:

```
ProgramHeader {
  Type: Unknown (0x60000000)
```

It was discussed in D85526 and consistent with what we print for
'--sections' already, e.g.:

```
Section {
  Name: .sec
  Type: Unknown (0x7FFFFFFF)
}
```

Differential revision: https://reviews.llvm.org/D86213
2020-08-25 13:05:17 +03:00
Georgii Rymar
ce5d5ddb40 [llvm-readelf/obj] - Change the return type of the createDRI(...) to Expected<>
This allows to get rid of "Invalid data was encountered while parsing the file"
error reported in cases when sh_size/sh_offset of sections are broken.

Differential revision: https://reviews.llvm.org/D86451
2020-08-25 12:11:26 +03:00
OCHyams
6420954176 [llvm-dwarfdump] Fix misleading scope byte coverage statistics
Fixes PR46575.

Bump statistics version to 6.

Without this patch, for a variable described with a location list the stat
'sum_all_variables(#bytes in parent scope covered by DW_AT_location)' is
calculated by summing all bytes covered by the location ranges in the list and
capping the result to the number of bytes in the parent scope. With the patch,
only bytes which overlap with the parent DIE scope address ranges contribute to
the stat. A new stat 'sum_all_variables(#bytes in any scope covered by
DW_AT_location)' has been added which displays the total bytes covered when
ignoring scopes.
2020-08-25 06:40:11 +01:00
Shoaib Meenai
5c9a439cf0 [llvm-libtool-darwin] Add support for -V option
The -V option in cctools' libtool prints out the version number and
performs any specified operation. Add this option to LLVM's version.
cctools is more forgiving of invalid command lines when -V is specified,
but I think it's better to give errors instead of silently producing no
output.

Unfortunately, when -V is present, options that would otherwise be
required aren't anymore, so we need to perform some manual argument
validation.

Reviewed By: alexshap

Differential Revision: https://reviews.llvm.org/D86359
2020-08-24 13:48:23 -07:00
Florian Hahn
27f75460b8 [llvm-reduce] Skip terminators when reducing instructions.
Removing terminators will result in invalid IR, making further
reductions pointless. I do not think there is any valid use case where
we actually want to create invalid IR as part of a reduction.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D86210
2020-08-23 17:20:34 +01:00
Fangrui Song
ed1bc644de [llvm-dwarfdump] --statistics: break lines and indent by 2
so that the user does not have to pipe the output to `jq` or `python -m json.tool`.
This change makes testing more convenient because `-NEXT` patterns can be used.
The "prettify by default" is a good tradeoff to make. The output size increases a bit.

Differential Revision: https://reviews.llvm.org/D86318
2020-08-22 13:58:18 -07:00
Tyker
d75baa4613 [llvm-reduce] make llvm-reduce save the best reduction it has when it crashes
This helps with both debugging llvm-reduce and sometimes getting usefull result even if llvm-reduce crashes

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D85996
2020-08-22 19:16:43 +02:00
Arthur Eubanks
5e4555a20b [opt][NewPM] Add basic-aa in legacy PM compatibility mode
The legacy PM alias analysis pipeline by default includes basic-aa.
When running `opt -foo-pass` under the NPM and -disable-basic-aa is not
specified, use basic-aa.

This decreases the number of check-llvm failures under NPM from 913 to 752.

Reviewed By: ychen, asbirlea

Differential Revision: https://reviews.llvm.org/D86167
2020-08-21 14:05:07 -07:00
Wolfgang Pieb
ce0e164b61 [llvm-mca][NFC] Refactor views to separate data collection from printing.
Reviewed By: andreadb, lebedev.ri

    Differential Revision: https://reviews.llvm.org/D86177
2020-08-21 11:27:36 -07:00
Georgii Rymar
5a7a553b60 [llvm-readobj/elf] - Refine the code for broken PT_DYNAMIC segment diagnostic.
The code that reports "PT_DYNAMIC segment offset + size exceeds the size of the file"
has an issue: it is possible to bypass the validation by overflowing the size + offset result.

Differential revision: https://reviews.llvm.org/D85519
2020-08-21 15:05:46 +03:00
Xing GUO
54320a5f65 Recommit: [DWARFYAML] Add support for referencing different abbrev tables.
The original commit (7ff0ace96db9164dcde232c36cab6519ea4fce8) was causing
build failure and was reverted in 6d242a73264ef1e3e128547f00e0fe2d20d3ada0

==================== Original Commit Message ====================
This patch adds support for referencing different abbrev tables. We use
'ID' to distinguish abbrev tables and use 'AbbrevTableID' to explicitly
assign an abbrev table to compilation units.

The syntax is:
```
debug_abbrev:
  - ID: 0
    Table:
      ...
  - ID: 1
    Table:
      ...
debug_info:
  - ...
    AbbrevTableID: 1 ## Reference the second abbrev table.
  - ...
    AbbrevTableID: 0 ## Reference the first abbrev table.
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83116
2020-08-21 19:02:10 +08:00
Georgii Rymar
53c4cabd9b [llvm-readelf] - Start recognizing 'PT_OPENBSD_*' segment types.
Its a follow-up for D85830, it stops ignoring 'PT_OPENBSD_*' segment types.
Now them are recognized properly.

Note: GNU readelf does not recognize them, though perhaps it shouldn't.
Anyways, it was reported to binutils: https://sourceware.org/bugzilla/show_bug.cgi?id=26405#c0

Differential revision: https://reviews.llvm.org/D86208
2020-08-21 13:13:05 +03:00
Georgii Rymar
ac79b2437e [llvm-readobj] - Change how we create DynRegionInfo objects. NFCI.
Currently we have `checkDRI` and two `createDRIFrom` methods which
are used to create `DynRegionInfo` objects.

And we have an issue: constructions like:
`ObjF->getELFFile()->base() + P->p_offset`
that are used in `createDRIFrom` functions might overflow.

I had to revert `D85519` which triggered such UBSan failure.

This NFC, simplifies and generalizes how we create `DynRegionInfo` objects.
It will allow us to introduce more/better validation checks in a single place.
It also will allow to change `createDRI` to return `Expected<>` so
that we will be able to stop using the `reportError`, which
is used inside currently, and have a warning instead.

Differential revision: https://reviews.llvm.org/D86297
2020-08-21 11:35:28 +03:00
Xing GUO
7720abc372 Revert "[DWARFYAML] Add support for referencing different abbrev tables."
This reverts commit f7ff0ace96db9164dcde232c36cab6519ea4fce8.

This change is causing build failure.

http://lab.llvm.org:8011/builders/clang-cmake-armv7-global-isel/builds/10400
2020-08-21 12:15:54 +08:00
Xing GUO
de84ba17c9 [DWARFYAML] Add support for referencing different abbrev tables.
This patch adds support for referencing different abbrev tables. We use
'ID' to distinguish abbrev tables and use 'AbbrevTableID' to explicitly
assign an abbrev table to compilation units.

The syntax is:
```
debug_abbrev:
  - ID: 0
    Table:
      ...
  - ID: 1
    Table:
      ...
debug_info:
  - ...
    AbbrevTableID: 1 ## Reference the second abbrev table.
  - ...
    AbbrevTableID: 0 ## Reference the first abbrev table.
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83116
2020-08-21 11:44:25 +08:00
Xing GUO
6752521113 [DWARFYAML] Add support for emitting multiple abbrev tables.
This patch adds support for emitting multiple abbrev tables. Currently,
compilation units will always reference the first abbrev table.

Reviewed By: jhenderson, labath

Differential Revision: https://reviews.llvm.org/D86194
2020-08-21 10:12:08 +08:00
Fangrui Song
4d9361b2f3 [llvm-dwarfdump] Fix a typo: witin -> within 2020-08-20 14:12:37 -07:00
Fangrui Song
2eec803753 [llvm-dwarfdump] --statistics: switch to json::OStream. NFC
Then it is trivial to make the output indented (the second parameter of
json::OStream::OStream specifies the indentation).

Reviewed By: jhenderson, echristo

Differential Revision: https://reviews.llvm.org/D86045
2020-08-20 12:24:06 -07:00
Georgii Rymar
e7c1ab412e Revert "[llvm-readobj/elf] - Refine the code for broken PT_DYNAMIC segment diagnostic."
This reverts commit 455d5a8a065b4b93df11d1696dc1546c403465a5.

It broke UBSan:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/21386/steps/check-llvm%20ubsan/logs/stdio

/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test:62:10: error: WARN3: expected string not found in input
# WARN3: error: '[[FILE]]': Invalid data was encountered while parsing the file
         ^
<stdin>:2:1: note: scanning from here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:1: note: with "FILE" equal to "/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/test/tools/llvm-readobj/ELF/Output/malformed-pt-dynamic\\.test\\.tmp3"
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:117: note: possible intended match here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
                                                                                                                    ^
Input file: <stdin>
Check file: /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test
2020-08-20 14:04:30 +03:00
Georgii Rymar
45c7e14aca [llvm-readobj/elf] - Refine the code for broken PT_DYNAMIC segment diagnostic.
The code that reports "PT_DYNAMIC segment offset + size exceeds the size of the file"
has an issue: it is possible to bypass the validation by overflowing the size + offset result.

Differential revision: https://reviews.llvm.org/D85519
2020-08-20 12:28:34 +03:00
Georgii Rymar
ab00fa2ce1 [yaml2obj] - Make the 'Machine' key optional.
Currently we have to set 'Machine' to something in our
YAML descriptions. Usually we use 'EM_X86_64' for 64-bit targets
and 'EM_386' for 32-bit targets. At the same time, in fact, in most
cases our tests do not need a machine type and we can use
'EM_NONE'.

This is cleaner, because avoids the need of using a particular machine.

In this patch I've made the 'Machine' key optional (the default value,
when it is not specified is `EM_NONE`) and removed it (where possible)
from yaml2obj, obj2yaml and llvm-readobj tests.

There are few tests left where I decided not to remove it, because
I didn't want to touch CHECK lines or doing anything more complex
than a removing a "Machine: *" line and formatting lines around.

Differential revision: https://reviews.llvm.org/D86202
2020-08-20 11:40:51 +03:00
Simon Pilgrim
b4fc1fb85b Fix MSVC implicit truncation narrowing conversion warning. 2020-08-19 14:41:40 +01:00
Xing GUO
6ada6c96e0 [obj2yaml] Refactor the .debug_pub* sections dumper.
It's good to reuse the DWARF parser in lib/DebugInfo so that we don't
need to maintain a separate parser in client side (obj2yaml). Besides,
A test case is added whose length field is a very huge value which makes
obj2yaml stuck when parsing the section.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86192
2020-08-19 21:13:52 +08:00
Ronak Chauhan
4697f34ed6 Revert "[AMDGPU] Support disassembly for AMDGPU kernel descriptors"
This reverts commit cacfb02d28a3cabd4e45d2535cb0686cef48a2c9.

Reverting due to buildbot failures.
2020-08-19 13:12:29 +05:30
Ronak Chauhan
142f4dd209 [AMDGPU] Support disassembly for AMDGPU kernel descriptors
Decode AMDGPU Kernel descriptors as assembler directives.

Reviewed By: scott.linder

Differential Revision: https://reviews.llvm.org/D80713
2020-08-19 08:49:07 +05:30
Ronak Chauhan
0f95014e38 [llvm-objdump][AMDGPU] Detect CPU string
AMDGPU ISA isn't backwards compatible and hence -mcpu must always be specified during disassembly.
However, the AMDGPU target CPU is stored in e_flags in the ELF object.

This patch allows targets to implement CPU string detection, and also implements it for AMDGPU by looking at e_flags.

Reviewed By: scott.linder

Differential Revision: https://reviews.llvm.org/D84519
2020-08-18 17:43:16 +05:30
Hongtao Yu
43bf988191 [llvm-objdump] Symbolize binary addresses for low-noisy asm diff.
When diffing disassembly dump of two binaries, I see lots of noises from mismatched jump target addresses and global data references, which unnecessarily causes diffs on every function, making it impractical. I'm trying to symbolize the raw binary addresses to minimize the diff noise.
In this change, a local branch target is modeled as a label and the branch target operand will simply be printed as a label. Local labels are collected by a separate pre-decoding pass beforehand. A global data memory operand will be printed as a global symbol instead of the raw data address. Unfortunately, due to the way the disassembler is set up and to be less intrusive, a global symbol is always printed as the last operand of a memory access instruction. This is less than ideal but is probably acceptable from checking code quality point of view since on most targets an instruction can have at most one memory operand.

So far only the X86 disassemblers are supported.

Test Plan:

llvm-objdump -d  --x86-asm-syntax=intel --no-show-raw-insn --no-leading-addr :
```
Disassembly of section .text:

<_start>:
               	push	rax
               	mov	dword ptr [rsp + 4], 0
               	mov	dword ptr [rsp], 0
               	mov	eax, dword ptr [rsp]
               	cmp	eax, dword ptr [rip + 4112]  # 202182 <g>
               	jge	0x20117e <_start+0x25>
               	call	0x201158 <foo>
               	inc	dword ptr [rsp]
               	jmp	0x201169 <_start+0x10>
               	xor	eax, eax
               	pop	rcx
               	ret
```

llvm-objdump -d  **--symbolize-operands** --x86-asm-syntax=intel --no-show-raw-insn --no-leading-addr :
```
Disassembly of section .text:

<_start>:
               	push	rax
               	mov	dword ptr [rsp + 4], 0
               	mov	dword ptr [rsp], 0
<L1>:
               	mov	eax, dword ptr [rsp]
               	cmp	eax, dword ptr  <g>
               	jge	 <L0>
               	call	 <foo>
               	inc	dword ptr [rsp]
               	jmp	 <L1>
<L0>:
               	xor	eax, eax
               	pop	rcx
               	ret
```

Note that the jump instructions like `jge 0x20117e <_start+0x25>` without this work is printed as a real target address and an offset from the leading symbol. With a change in the optimizer that adds/deletes an instruction, the address and offset may shift for targets placed after the instruction. This will be a problem when diffing the disassembly from two optimizers where there are unnecessary false positives due to such branch target address changes. With `--symbolize-operand`, a label is printed for a branch target instead to reduce the false positives. Similarly, the disassemble of PC-relative global variable references is also prone to instruction insertion/deletion.

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D84191
2020-08-17 16:55:12 -07:00
Georgii Rymar
fe476e8dfc [llvm-readobj] - Remove unwrapOrError calls from GNUStyle<ELFT>::printRelocations.
This fixes existent FIXMEs: we should not error out when unable to
find the number of relocations.

Differential revision: https://reviews.llvm.org/D85891
2020-08-17 15:16:36 +03:00
Georgii Rymar
cd6681160b [llvm-readobj/elf] - Refine the warning about the broken PT_DYNAMIC segment.
Splitted out from D85519.

Currently we report "PT_DYNAMIC segment offset + size exceeds the size of the file",
this changes it to
"PT_DYNAMIC segment offset (0x1234) + file size (0x5678) exceeds the size of the file (0x68ab)"

Differential revision: https://reviews.llvm.org/D85654
2020-08-17 14:57:19 +03:00
Shoaib Meenai
8de4e46dad [llvm-libtool-darwin] Use Optional operator overloads. NFC
Use operator bool instead of hasValue and operator* instead of getValue
to simplify the code slightly.
2020-08-15 11:41:57 -07:00