Commit Graph

6 Commits

Author SHA1 Message Date
Fangrui Song 011b785505 [ELF] Create readonly PT_LOAD in the presence of a SECTIONS command
This essentially drops the change by r288021 (discussed with Georgii Rymar
and Peter Smith and noted down in the release note of lld 10).

GNU ld>=2.31 enables -z separate-code by default for Linux x86. By
default (in the absence of a PHDRS command) a readonly PT_LOAD is
created, which is different from its traditional behavior.

Not emulating GNU ld's traditional behavior is good for us because it
improves code consistency (we create a readonly PT_LOAD in the absence
of a SECTIONS command).

Users can add --no-rosegment to restore the previous behavior (combined
readonly and read-executable sections in a single RX PT_LOAD).
2020-03-19 19:11:11 -07:00
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 5d4bc1293c [ARM][test] Improve tests
Delete trailing 2>&1 that is not piped to another command.
Add --no-show-raw-insn to objdump -d commands.

llvm-svn: 366676
2019-07-22 11:37:03 +00:00
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
Peter Smith 13d134684f [ELF] Implement option to force PIC compatible Thunks
By default LLD will generate position independent Thunks when the --pie or
--shared option is used. Reference to absolute addresses is permitted in
other cases. For some embedded systems position independent thunks are
needed for code that executes before the MMU has been set up. The option
--pic-veneer is used by ld.bfd to force position independent thunks.
    
The patch adds --pic-veneer as the option is needed for the Linux kernel
on Arm.
    
fixes pr39886
    
Differential Revision: https://reviews.llvm.org/D55505

llvm-svn: 351326
2019-01-16 12:09:13 +00:00