Commit Graph

9 Commits

Author SHA1 Message Date
Fangrui Song 962b29d716 ELFObjectWriter: Don't sort non-local symbols
As we don't sort local symbols, don't sort non-local symbols.  This makes
non-local symbols appear in their register order, which matches GNU as. The
register order is nice in that you can write tests with interleaved CHECK
prefixes, e.g.

```
// CHECK: something about foo
.globl foo
foo:
// CHECK: something about bar
.globl bar
bar:
```

With the lexicographical order, the user needs to place lexicographical smallest
symbol first or keep CHECK prefixes in one place.
2021-02-13 10:32:27 -08:00
Fangrui Song 3f8dda50cb [test] Fix unuses FileCheck prefixes in lld 2021-02-01 20:52:33 -08:00
Fangrui Song f0374e7db2 [test] lld/test/: change llvm-objdump single-dash long options to double-dash options 2020-03-15 17:48:36 -07:00
Fangrui Song 71e2ca6e32 [llvm-objdump] -d: print `00000000 <foo>:` instead of `00000000 foo:`
The new behavior matches GNU objdump. A pair of angle brackets makes tests slightly easier.

`.foo:` is not unique and thus cannot be used in a `CHECK-LABEL:` directive.
Without `-LABEL`, the CHECK line can match the `Disassembly of section`
line and causes the next `CHECK-NEXT:` to fail.

```
Disassembly of section .foo:

0000000000001634 .foo:
```

Bdragon: <> has metalinguistic connotation. it just "feels right"

Reviewed By: rupprecht

Differential Revision: https://reviews.llvm.org/D75713
2020-03-05 18:05:28 -08:00
Fangrui Song f9a0056016 [llvm-objdump] --syms: make flags closer to GNU objdump
This fixes several issues. The behavior changes are:

A SHN_COMMON symbol does not have the 'g' flag.
An undefined symbol does not have 'g' or 'l' flag.
A STB_GLOBAL SymbolRef::ST_Unknown symbol has the 'g' flag.
A STB_LOCAL SymbolRef::ST_Unknown symbol has the 'l' flag.

Reviewed By: rupprecht

Differential Revision: https://reviews.llvm.org/D75659
2020-03-05 09:59:53 -08:00
Jordan Rupprecht 9d4a6b1bb2 [llvm-objdump] Further rearrange llvm-objdump sections for compatability
Summary:
rL371826 rearranged some output from llvm-objdump for GNU objdump compatability, but there still seem to be some more.

I think this rearrangement is a little closer. Overview of the ordering which matches GNU objdump:
* Archive headers
* File headers
* Section headers
* Symbol table
* Dwarf debugging
* Relocations (if `--disassemble` is not used)
* Section contents
* Disassembly

Reviewers: jhenderson, justice_adams, grimar, ychen, espindola

Reviewed By: jhenderson

Subscribers: aprantl, emaste, arichardson, jrtc27, atanasyan, seiya, llvm-commits, MaskRay

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68066

llvm-svn: 373671
2019-10-03 22:01:08 +00:00
Simon Atanasyan 2439b8b0c5 [mips] Make another set of test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371458
2019-09-09 22:04:20 +00:00
Simon Atanasyan 56e4ea2bff [mips] Fix decoding of microMIPS JALX instruction
microMIPS jump and link exchange instruction stores a target in a
26-bits field. Despite other microMIPS JAL instructions these bits
are target address shifted right 2 bits [1]. The patch fixes the
JALX instruction decoding and uses 2-bit shift.

[1] MIPS Architecture for Programmers Volume II-B: The microMIPS32 Instruction Set

Differential Revision: https://reviews.llvm.org/D67320

llvm-svn: 371428
2019-09-09 17:28:45 +00:00
Simon Atanasyan fae2a509fa [MIPS] Handle cross-mode (regular <-> microMIPS) jumps
The patch solves two tasks:

1. MIPS ABI allows to mix regular and microMIPS code and perform
cross-mode jumps. Linker needs to detect such cases and replace
jump/branch instructions by their cross-mode equivalents.

2. Other tools like dunamic linkers need to recognize cases when dynamic
table entries, e_entry field of an ELF header etc point to microMIPS
symbol. Linker should provide such information.

The first task is implemented in the `MIPS<ELFT>::relocateOne()` method.
New routine `fixupCrossModeJump` detects ISA mode change, checks and
replaces an instruction.

The main problem is how to recognize that relocation target is microMIPS
symbol. For absolute and section symbols compiler or assembler set the
less-significant bit of the symbol's value or sum of the symbol's value
and addend. And this bit signals to linker about microMIPS code. For
global symbols compiler cannot do the same trick because other tools like,
for example, disassembler wants to know an actual position of the symbol.
So compiler sets STO_MIPS_MICROMIPS flag in the `st_other` field.

In `MIPS<ELFT>::relocateOne()` method we have a symbol's value only and
cannot access any symbol's attributes. To pass type of the symbol
(regular/microMIPS) to that routine as well as other places where we
write a symbol value as-is (.dynamic section, `Elf_Ehdr::e_entry` field
etc) we set when necessary a less-significant bit in the `getSymVA`
function.

Differential revision: https://reviews.llvm.org/D40147

llvm-svn: 354311
2019-02-19 10:36:58 +00:00