Commit Graph

11 Commits

Author SHA1 Message Date
Fangrui Song 6d637fa560 [ELF][test] Delete large temporary files and make some temporary files smaller with two text segments
Large files are cumbersome on some filesystems and can more easily trigger ENOSPC.

Some tests use two text sections with output section addresses to test branch ranges.
Use two text segments to prevent LLD from filling the gap and unnecessarily increasing the output size.

With this change, there is no test/ELF temporary file larger than 100MiB.

Reviewed By: psmith

Differential Revision: https://reviews.llvm.org/D88037
2020-09-21 12:09:17 -07:00
Peter Collingbourne bd7defeb94 llvm-nm: Implement --special-syms.
Differential Revision: https://reviews.llvm.org/D82251
2020-06-22 13:05:47 -07:00
Fangrui Song 7f36cb1f1a [AArch64InstPrinter] Change printAlignedLabel to print the target address in hexadecimal form
Similar to D76580 (x86) and D76591 (PPC).

```
// llvm-objdump -d output (before)
10000: 08 00 00 94                   bl      #32
10004: 08 00 00 94                   bl      #32

// llvm-objdump -d output (after)
10000: 08 00 00 94                   bl      0x10020
10004: 08 00 00 94                   bl      0x10024

// GNU objdump -d. The lack of 0x is not ideal due to ambiguity.
10000:       94000008        bl      10020 <bar+0x18>
10004:       94000008        bl      10024 <bar+0x1c>
```

The new output makes it easier to find the jump target.

Differential Revision: https://reviews.llvm.org/D77853
2020-04-10 09:21:09 -07:00
Fangrui Song a13212582a [ELF][test] Test that thunks are processed before finalizeSynthetic(in.symTab)
finalizeSynthetic(in.symTab) calls sortSymTabSymbols() to order local
symbols before non-local symbols.

The newly added tests ensure that thunk symbols are added before
finalizeSynthetic(in.symTab), otherwise .symtab would be out of order.
2020-04-04 10:57:37 -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 870094decf [ELF] Decrease alignment of ThunkSection on 64-bit targets from 8 to 4
ThunkSection contains 4-byte instructions on all targets that use
thunks. Thunks should not be used in any performance sensitive places,
and locality/cache line/instruction fetching arguments should not apply.

We use 16 bytes as preferred function alignments for modern PowerPC cores.
In any case, 8 is not optimal.

Differential Revision: https://reviews.llvm.org/D72819
2020-01-16 10:36:33 -08:00
Fangrui Song bf535ac4a2 [ELF][AArch64] Support R_AARCH64_{CALL26,JUMP26} range extension thunks with addends
Fixes AArch64 part of PR40438

The current range extension thunk framework does not handle a relocation
relative to a STT_SECTION symbol with a non-zero addend, which may be
used by jumps/calls to local functions on some RELA targets (AArch64,
powerpc ELFv1, powerpc64 ELFv2, etc).  See PR40438 and the following
code for examples:

  // clang -target $target a.cc
  // .text.cold may be placed in a separate output section.
  // The distance between bar in .text.cold and foo in .text may be larger than 128MiB.
  static void foo() {}
  __attribute__((section(".text.cold"))) static int bar() { foo(); return
  0; }
  __attribute__((used)) static int dummy = bar();

This patch makes such thunks with addends work for AArch64. The target
independent part can be reused by PPC in the future.

On REL targets (ARM, MIPS), jumps/calls are not represented as
STT_SECTION + non-zero addend (see
MCELFObjectTargetWriter::needsRelocateWithSymbol), so they don't need
this feature, but we need to make sure this patch does not affect them.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D70637
2019-12-02 10:07:24 -08:00
Fangrui Song 6b90f2bbec [ELF][test] Clean up some thunk tests
Use llvm-objdump --no-show-raw-insn --print-imm-hex
Prefer generic aarch64 triple to linux/freebsd specific triples.
2019-11-23 12:42:39 -08:00
Fangrui Song 5387c2cd17 [llvm-objdump] Print newlines before and after "Disassembly of section ...:"
This improves readability and the behavior is consistent with GNU objdump.

The new test test/tools/llvm-objdump/X86/disassemble-section-name.s
checks we print newlines before and after "Disassembly of section ...:"

Differential Revision: https://reviews.llvm.org/D61127

llvm-svn: 359668
2019-05-01 10:40:48 +00:00
Fangrui Song b6772b86e2 [ELF] Move `// REQUIRES:` line to the top
llvm-svn: 335676
2018-06-26 22:20:04 +00:00
Peter Smith 31dddc97ae [ELF][AArch64] Add support for AArch64 range thunks.
The AArch64 unconditional branch and branch and link instructions have a
maximum range of 128 Mib. This is usually enough for most programs but
there are cases when it isn't enough. This change adds support for range
extension thunks to AArch64. For pc-relative thunks we follow the small
code model and use ADRP, ADD, BR. This has a limit of 4 gigabytes.

Differential Revision: https://reviews.llvm.org/D39744

llvm-svn: 319307
2017-11-29 11:15:12 +00:00