If a file has no symbols, perhaps because it is a linked executable,
synthesize some symbols by walking the code section. Otherwise the
disassembler will try to treat the whole code section as a function,
which won't parse. Fixes https://bugs.llvm.org/show_bug.cgi?id=50957.
Differential Revision: https://reviews.llvm.org/D105539
The patch reuses the common code to print memory operand addresses as
instruction comments. This helps to align the comments and enables using
target-specific comment markers when `evaluateMemoryOperandAddress()` is
implemented for them.
Differential Revision: https://reviews.llvm.org/D104861
For now, the source variable locations are printed at about the same
space as the comments for disassembled code, which can make some ranges
for variables disappear if a line contains comments, for example:
┠─ bar = W1
0: add x0, x2, #2, lsl #12 // =8192┃
4: add z31.d, z31.d, #65280 // =0xff00
8: nop ┻
The patch shifts the report a bit to allow printing comments up to
approximately 16 characters without interferences.
Differential Revision: https://reviews.llvm.org/D104700
LLVM disassembler can generate comments for disassembled instructions.
The patch enables printing these comments for 'llvm-objdump -d'.
Differential Revision: https://reviews.llvm.org/D104699
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
Summary: Under the option --section-headers, we can only
print the section types of TEXT, DATA, and BSS for now.
This patch adds the DEBUG type.
Reviewed By: jhenderson, Higuoxing
Differential Revision: https://reviews.llvm.org/D102603
This makes it possible for targets to define their own MCObjectFileInfo.
This MCObjectFileInfo is then used to determine things like section alignment.
This is a follow up to D101462 and prepares for the RISCV backend defining the
text section alignment depending on the enabled extensions.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101921
`__mh_(execute|dylib|dylinker|bundle|preload|object)_header` are special symbols whose values hold the VMA of the Mach header to support introspection. They are attached to the first section in `__TEXT`, even though their addresses are outside `__TEXT`, and they do not refer to code.
It is normally harmless, but when the first section of `__TEXT` has no other symbols, `__mh_*_header` is considered by the disassembler when determing function boundaries. Since `__mh_*_header` refers to an address outside `__TEXT`, the boundary determination fails and disassembly quits.
Since `__TEXT,__text` normally has symbols, this bug is obscured. Experiments placing `__stubs` and `__stub_helper` first exposed the bug, since neither has symbols.
Differential Revision: https://reviews.llvm.org/D101786
Fix up my recent commit rG1128311a19179ceca799ff0fbc4dd206ab56e560 to
use std::make_unique instead of std::unique_ptr(new), as requested by
David Blaikie.
Differential Revision: https://reviews.llvm.org/D101822
This untangles the MCContext and the MCObjectFileInfo. There is a circular
dependency between MCContext and MCObjectFileInfo. Currently this dependency
also exists during construction: You can't contruct a MOFI without a MCContext
without constructing the MCContext with a dummy version of that MOFI first.
This removes this dependency during construction. In a perfect world,
MCObjectFileInfo wouldn't depend on MCContext at all, but only be stored in the
MCContext, like other MC information. This is future work.
This also shifts/adds more information to the MCContext making it more
available to the different targets. Namely:
- TargetTriple
- ObjectFileType
- SubtargetInfo
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101462
The internal `cl::opt` option --x86-asm-syntax sets the AsmParser and AsmWriter
dialect. The option is used by llc and llvm-mc tests to set the AsmWriter dialect.
This patch adds -M {att,intel} as GNU objdump compatible aliases (PR43413).
Note: the dialect is initialized when the MCAsmInfo is constructed.
`MCInstPrinter::applyTargetSpecificCLOption` is called too late and its MCAsmInfo
reference is const, so changing the `cl::opt` in
`MCInstPrinter::applyTargetSpecificCLOption` is not an option, at least without
large amount of refactoring.
Reviewed By: hoy, jhenderson, thakis
Differential Revision: https://reviews.llvm.org/D101695
When dumping multiple pieces of information (e.g. --all-headers),
there is sometimes no separator between two pieces.
This patch uses the "\nheader:\n" style, which generally improves
compatibility with GNU objdump.
Note: objdump -t/-T does not add a newline before "SYMBOL TABLE:" and "DYNAMIC SYMBOL TABLE:".
We add a newline to be consistent with other information.
`objdump -d` prints two empty lines before the first 'Disassembly of section'.
We print just one with this patch.
Differential Revision: https://reviews.llvm.org/D101796
1. Add an accessor function to MCSymbolizer to retrieve addresses
referenced by a symbolizable operand, but not resolved to a symbol.
That way, the caller can synthesize labels at those addresses and
then retry disassembling the section.
2. Implement that in AMDGPU -- a failed symbol lookup results in the
address being added to a vector returned by the new function.
3. Use that in llvm-objdump when using MCSymbolizer (which only happens
on AMDGPU) and SymbolizeOperands is on.
Differential Revision: https://reviews.llvm.org/D101145
Change-Id: I19087c3bbfece64bad5a56ee88bcc9110d83989e
This implements an LLVM tool that's flag- and output-compatible
with macOS's `otool` -- except for bugs, but from testing with both
`otool` and `xcrun otool-classic`, llvm-otool matches vanilla
otool's behavior very well already. It's not 100% perfect, but
it's a very solid start.
This uses the same approach as llvm-objcopy: llvm-objdump uses
a different OptTable when it's invoked as llvm-otool. This
is possible thanks to D100433.
Differential Revision: https://reviews.llvm.org/D100583
This is similar to D83530, but for llvm-objdump.
The motivation is the desire to add an `llvm-otool` symlink to
llvm-objdump that behaves like macOS's `otool`, using the same
technique the at llvm-objcopy uses to behave like `strip` (etc).
This change for the most part preserves behavior. In some cases,
it increases compatibility with GNU objdump a bit. For example,
the long options now require two dashes, and the long options
taking arguments for the most part now require a `=` in front
of the value. Exceptions are flags where tests passed the
value separately, for these the separate form is kept as
an alias to the = form.
The one-letter short form args are now joined or separate
and long longer accept a =, which also matches GNU objdump.
cl::opt<>s in libraries now have to be explicitly plumbed
through. This patch does that for --x86-asm-syntax=, but
there's hope that we can remove that again.
Differential Revision: https://reviews.llvm.org/D100433
The option `--prefix-strip` is only used when `--prefix` is not empty.
It removes N initial directories from absolute paths before adding the
prefix.
This matches GNU's objdump behavior.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D96679
Warnings have been added for three cases (PR41905): (1) missing debug info, (2)
the source file cannot be found, (3) the debug info points at a line beyond the
end of the file.
(1) is probably less useful. This was brought up once on
http://lists.llvm.org/pipermail/llvm-dev/2020-April/141264.html and two
internal users mentioned it to me that it was annoying. (I personally
find the warning confusing, too.)
Users specify --source to get additional information if sources happen to be
available. If sources are not available, it should be obvious as the output
will have no interleaved source lines. The warning can be especially annoying
when using llvm-objdump -S on a bunch of files.
This patch drops the warning when there is no debug info.
(If LLVMSymbolizer::symbolizeCode returns an `Error`, there will still be
an error. There is currently no test for an `Error` return value.
The only code path is probably a broken symbol table, but we probably already emit a warning
in that case)
`source-interleave-prefix.test` has an inappropriate "malformed" test - the test simply has no
.debug_* because new llc does not produce debug info when the filename is empty (invalid).
I have tried tampering the header of .debug_info/.debug_line but llvm-symbolizer does not warn.
This patch does not intend to add the missing test coverage.
Differential Revision: https://reviews.llvm.org/D88715
FaultsMapParser lived in CodeGen and was forcing llvm-objdump to
link CodeGen and everything CodeGen depends on.
This was previously attempted in r240364 to fix a link failure.
The CodeGen dependency was independently added to fix the same
link failure, and that ended up being kept.
Removing the dependency seems like the correct layering for
llvm-objdump.
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D95414
Part of the <=> changes in C++20 make certain patterns of writing equality
operators ambiguous with themselves (sorry!).
This patch goes through and adjusts all the comparison operators such that
they should work in both C++17 and C++20 modes. It also makes two other small
C++20-specific changes (adding a constructor to a type that cases to be an
aggregate, and adding casts from u8 literals which no longer have type
const char*).
There were four categories of errors that this review fixes.
Here are canonical examples of them, ordered from most to least common:
// 1) Missing const
namespace missing_const {
struct A {
#ifndef FIXED
bool operator==(A const&);
#else
bool operator==(A const&) const;
#endif
};
bool a = A{} == A{}; // error
}
// 2) Type mismatch on CRTP
namespace crtp_mismatch {
template <typename Derived>
struct Base {
#ifndef FIXED
bool operator==(Derived const&) const;
#else
// in one case changed to taking Base const&
friend bool operator==(Derived const&, Derived const&);
#endif
};
struct D : Base<D> { };
bool b = D{} == D{}; // error
}
// 3) iterator/const_iterator with only mixed comparison
namespace iter_const_iter {
template <bool Const>
struct iterator {
using const_iterator = iterator<true>;
iterator();
template <bool B, std::enable_if_t<(Const && !B), int> = 0>
iterator(iterator<B> const&);
#ifndef FIXED
bool operator==(const_iterator const&) const;
#else
friend bool operator==(iterator const&, iterator const&);
#endif
};
bool c = iterator<false>{} == iterator<false>{} // error
|| iterator<false>{} == iterator<true>{}
|| iterator<true>{} == iterator<false>{}
|| iterator<true>{} == iterator<true>{};
}
// 4) Same-type comparison but only have mixed-type operator
namespace ambiguous_choice {
enum Color { Red };
struct C {
C();
C(Color);
operator Color() const;
bool operator==(Color) const;
friend bool operator==(C, C);
};
bool c = C{} == C{}; // error
bool d = C{} == Red;
}
Differential revision: https://reviews.llvm.org/D78938
This was requested in comments for D93209:
https://reviews.llvm.org/D93209#inline-871192
D93209 fixes an issue with `ELFFile<ELFT>::getEntry`,
after what `getSymbol` starts calling `report_fatal_error` for previously
missed invalid cases.
This patch makes it return `Expected<>` and updates callers.
For few of them I had to add new `report_fatal_error` calls. But I see no
way to avoid it currently. The change would affects too many places, e.g:
`getSymbolBinding` and other methods are used from `ELFSymbolRef`
which is used in too many places across LLVM.
Differential revision: https://reviews.llvm.org/D93297
Single dash for these options is not recognised.
Changes found by running this on the --help output
and the user guide:
grep -e ' -[a-zA-Z]\{2,\}'
The user guide was updated in https://reviews.llvm.org/D92305
so no change there.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D92310
This does the same as `--mcpu=help` but was only
documented in the user guide.
* Added a test for both options.
* Corrected the single dash in `-mcpu=help` text.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D92305
The prefix given to --prefix will be added to GNU absolute paths when
used with --source option (source interleaved with the disassembly).
This matches GNU's objdump behavior.
GNU and C++17 rules for absolute paths are different.
Differential Revision: https://reviews.llvm.org/D85024
Fixes PR46368.
Differential Revision: https://reviews.llvm.org/D85024
I recently came across a MachO with multiple sections of the same name but
different segments. We should emit the segment name alongside the section name
for MachO's.
Differential Revision: https://reviews.llvm.org/D87119
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
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
If the referenced symbol of a J[U]MP_SLOT is invalid (e.g. symbol index 0), llvm-objdump -d will bail out:
```
error: 'a': st_name (0x326600) is past the end of the string table of size 0x7
```
where 0x326600 is the st_name field of the first entry past the end of .symtab
Change it to a warning to continue dumping.
`X86/plt.test` uses a prebuilt executable, so I pick `ELF/AArch64/plt.test`
which has a YAML input and can be easily modified.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D85623
This adds the --debug-vars option to llvm-objdump, which prints
locations (registers/memory) of source-level variables alongside the
disassembly based on DWARF info. A vertical line is printed for each
live-range, with a label at the top giving the variable name and
location, and the position and length of the line indicating the program
counter range in which it is valid.
Differential revision: https://reviews.llvm.org/D70720
