Commit Graph

10 Commits

Author SHA1 Message Date
Nico Weber c29003813a Revert "[LLD][ELF][ARM] Do not substitute BL/BLX for non STT_FUNC symbols."
There are still problems after the fix in
"[ELF][ARM] Fix regression of BL->BLX substitution after D73542"
so let's revert to get trunk back to green while we investigate.
See https://reviews.llvm.org/D73542

This reverts commit 5461fa2b1f.
This reverts commit 0b4a047bfb.
2020-02-07 08:55:52 -05:00
Peter Smith 0b4a047bfb [LLD][ELF][ARM] Do not substitute BL/BLX for non STT_FUNC symbols.
D73474 disabled the generation of interworking thunks for branch
relocations to non STT_FUNC symbols. This patch handles the case of BL and
BLX instructions to non STT_FUNC symbols. LLD would normally look at the
state of the caller and the callee and write a BL if the states are the
same and a BLX if the states are different.

This patch disables BL/BLX substitution when the destination symbol does
not have type STT_FUNC. This brings our behavior in line with GNU ld which
may prevent difficult to diagnose runtime errors when switching to lld.

Differential Revision: https://reviews.llvm.org/D73542
2020-01-29 11:42:25 +00:00
Fangrui Song 024bf27ddf [ELF][ARM] Allow PT_LOAD to have overlapping p_offset ranges on EM_ARM
Port the D64906 technique to ARM. It deletes 3 alignments at
PT_LOAD boundaries for the default case: the size of an arm binary
decreases by at most 12kb.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D66749

llvm-svn: 370049
2019-08-27 11:52:36 +00:00
Fangrui Song fdbc2bd2aa [ELF][ARM] Add --no-show-raw-insn and -soname to some ARM tests
Delete some insignificant addresses to make it simpler for layout
changes.

llvm-svn: 370048
2019-08-27 11:50:27 +00:00
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
Fangrui Song b6772b86e2 [ELF] Move `// REQUIRES:` line to the top
llvm-svn: 335676
2018-06-26 22:20:04 +00:00
Rafael Espindola f846ce259a Fix weak symbols on arm and aarch64.
Given

.weak target
 .global _start
_start:
 b target

The intention is that the branch goes to the instruction after the
branch, effectively turning it on a nop.  The branch adds the runtime
PC, but we were adding it statically too.

I noticed the oddity by inspection, but llvm-objdump seems to agree,
since it now prints things like:

b       #-4 <_start+0x4>

llvm-svn: 305212
2017-06-12 18:05:01 +00:00
Rafael Espindola d2a1b944bc Don't check the raw bits in tests.
It is not needed since we have the disassemble.

llvm-svn: 305096
2017-06-09 18:07:34 +00:00
Peter Smith 8339bbd759 [ELF] ARM and AArch64 undefined weak reference values
The ARM 32 and 64-bit ABI does not use 0 for undefined weak references
that are used in PC relative relocations. In particular:
- A branch relocation to an undefined weak resolves to the next
  instruction. Effectively making the branch a no-op
- In all other cases the symbol resolves to the place so that S + A - P
  resolves to A.

Differential Revision: https://reviews.llvm.org/D26240

llvm-svn: 286353
2016-11-09 10:22:29 +00:00