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
Summary:
This commit slightly modifies the MCDisassembler, and llvm-objdump to
allow targets to also decode entire symbols.
WebAssembly uses the onSymbolStart hook it to decode preludes.
WebAssembly partially disassembles the symbol in its target specific
way; and then falls back to the normal flow of llvm-objdump.
AMDGPU needs it to decode kernel descriptors entirely, and move to the
next symbol.
This commit is to split the above task into 2.
- Changes to llvm-objdump and MC-layer without breaking WebAssembly code
[ this commit ]
- AMDGPU's implementation of onSymbolStart that decodes kernel
descriptors. [ https://reviews.llvm.org/D80713 ]
Reviewers: scott.linder, t-tye, sunfish, arsenm, jhenderson, MaskRay, aardappel
Reviewed By: scott.linder, jhenderson, aardappel
Subscribers: bcain, dschuff, wdng, tpr, sbc100, jgravelle-google, hiraditya, aheejin, MaskRay, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80512
Place the instruction at the 24th column (0-based indexing), matching
GNU objdump ARM/AArch64/powerpc/etc when the address is low.
This is beneficial for non-x86 targets which have short instruction
lengths.
```
// GNU objdump AArch64
0: 91001062 add x2, x3, #0x4
400078: 91001062 add x2, x3, #0x4
// llvm-objdump, with this patch
0: 62 10 00 91 add x2, x3, #4
400078: 62 10 00 91 add x2, x3, #4
// llvm-objdump, if we change to print a word instead of bytes in the future
0: 91001062 add x2, x3, #4
400078: 91001062 add x2, x3, #4
// GNU objdump Thumb
0: bf00 nop
// GNU objdump Power ISA 3.1 64-bit instruction
// 0: 00 00 10 04 plwa r3,0
// 4: 00 00 60 a4
```
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D81590
As noticed by dblaikie.
I don't know what code paths using reportError can cause stdout output
to be interleaved with stderr, so no test is added now.
Also drop an unneeded use of errs().fflush() in reportWarning().
I requested this in D64165.
Fixes PR44357
For ARM ELF, regions covered by data mapping symbols `$d` are dumped as `.byte`, `.short` or `.word` but inline relocations are not printed. This patch merges its loop into the normal instruction printing loop so that inline relocations are printed.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D79284
D63847 added `MCInstrAnalysis::evaluateMemoryOperandAddress()`. This patch
leverages the feature to print the target addresses for evaluable instructions.
```
-400a: movl 4080(%rip), %eax
+400a: movl 4080(%rip), %eax # 5000 <data1>
```
This patch also deletes `MIA->isCall(Inst) || MIA->isUnconditionalBranch(Inst) || MIA->isConditionalBranch(Inst)`
which is used to guard `MCInstrAnalysis::evaluateBranch()`
Reviewed By: jhenderson, skan
Differential Revision: https://reviews.llvm.org/D78776
Summary:
Continuing from D77285, the external interfaces implemented by
`ELFDump.cpp` are now declared in `ELFDump.h` and moved into the
`llvm::objdump` namespace. Externs defined in `ELFDump.cpp` that are
unreferenced externally are also made static.
Reviewers: jhenderson, MaskRay, DiggerLin, jasonliu, daltenty
Reviewed By: jhenderson, MaskRay
Subscribers: RKSimon, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78695
Prior to this patch, llvm-objdump would only look in the last section
(according to the section header table order) that matched an address
for a symbol when identifying the target symbol of a call or branch
operation. If there are multiple sections with the same address, due to
some of them being empty, it did not look in those, even if the symbol
couldn't be found in the first section looked in.
This patch causes llvm-objdump to look in all sections for possible
candidate symbols. If there are multiple possible symbols, it picks one
from a non-empty section, if possible (as that is more likely to be the
"real" symbol since functions can't really be in emptiy sections),
before falling back to those in empty sections. If all else fails, it
falls back to absolute symbols as it did before.
Differential Revision: https://reviews.llvm.org/D78549
Reviewed by: grimar, Higuoxing
Currently C++ symbols are demangled in the symbol table as well as in
the disassembly and relocations. This patch adds demangling of C++
symbols in targets of calls and branches making it easier to decipher
control flow in disassembly. This also matches up with GNUobjdump's
behavior
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D77957
Summary:
Continuing from D77285, the external interfaces implemented by
`WasmDump.cpp` are now declared in `WasmDump.h` and moved into the
`llvm::objdump` namespace.
Reviewers: jhenderson, MaskRay, DiggerLin, jasonliu, daltenty
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D77990
This patch intends to fix incomplete relocation printing for
XCOFF (potentially for other targets).
Differential Revision: https://reviews.llvm.org/D77580
Ronak Chauhan
Hongtao Yu
Fangrui Song
Simon Pilgrim
Oliver Stannard
Reid Kleckner
Fangrui Song
Nico Weber
Hubert Tong
jasonliu
James Henderson
Markus Böck
vgxbj
Hubert Tong