Commit Graph

7 Commits

Author SHA1 Message Date
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +00:00
Peter Smith 3ce9af9370 [ELF][ARM] Recommit Redesign of .ARM.exidx handling to use a SyntheticSection
Recommit r356666 with fixes for buildbot failure, as well as handling for
--emit-relocs, which we decide not to emit any relocation sections as the
table is already position independent and an offline tool can deduce the
relocations.

Instead of creating extra Synthetic .ARM.exidx sections to account for
gaps in the table, create a single .ARM.exidx SyntheticSection that can
derive the contents of the gaps from a sorted list of the executable
InputSections. This has the benefit of moving the ARM specific code for
SyntheticSections in SHF_LINK_ORDER processing and the table merging code
into the ARM specific SyntheticSection. This also makes it easier to create
EXIDX_CANTUNWIND table entries for executable InputSections that don't
have an associated .ARM.exidx section.

Fixes pr40277

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 357160
2019-03-28 11:10:20 +00:00
Peter Smith 54dab70bb7 [ELF][ARM] Revert Redesign of .ARM.exidx handling to use a SyntheticSection
There is a reproducible buildbot failure (segfault) on the 2 stage
clang-cmake-armv8-lld bot. Reverting while I investigate.

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 356684
2019-03-21 17:17:54 +00:00
Peter Smith d3511a214e [ELF][ARM] Redesign of .ARM.exidx handling to use a SyntheticSection
Instead of creating extra Synthetic .ARM.exidx sections to account for
gaps in the table, create a single .ARM.exidx SyntheticSection that can
derive the contents of the gaps from a sorted list of the executable
InputSections. This has the benefit of moving the ARM specific code for
SyntheticSections in SHF_LINK_ORDER processing and the table merging code
into the ARM specific SyntheticSection. This also makes it easier to create
EXIDX_CANTUNWIND table entries for executable InputSections that don't
have an associated .ARM.exidx section.

Fixes pr40277

Differential Revision: https://reviews.llvm.org/D59216

llvm-svn: 356666
2019-03-21 14:06:40 +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 719eb8efa5 [ELF] Add terminating sentinel .ARM.exidx table entry
The .ARM.exidx table has an entry for each function with the first entry
giving the start address of the function, the table is sorted in ascending
order of function address. Given a PC value, the unwinder will search the
table for the entry that contains the PC value.
    
If the table entry happens to be the last, the range of the addresses that
the final unwinding table describes will extend to the end of the address
space. To prevent an incorrect address outside the address range of the
program matching the last entry we follow ld.bfd's example and add a
sentinel EXIDX_CANTUNWIND entry at the end of the table. This gives the
final real table entry an upper bound.
    
In addition the llvm libunwind unwinder currently depends on the presence
of a sentinel entry (PR31091).

Differential revision: https://reviews.llvm.org/D26977

llvm-svn: 287869
2016-11-24 11:43:55 +00:00
Peter Smith 8646ced053 Initial support for ARM in lld.
Add support for an ARM Target and the initial set of relocations
    and PLT entries that are necessary for an ARM only hello world to
    link. This has been tested against an ARM only sysroot from the
    4.2.0 CodeSourcery Lite release.
    
    Tests have been added to test/ELF for the support that has been
    implemented.
    
    Main limitations:
    - No Thumb support
    - Relocations incomplete
    - No C++ exceptions support
    - No TLS support
    - No range extension or interworking veneer (thunk) support
    - No Build Attribute support
    - No Big-endian support
    
    The deprecated relocations R_ARM_PLT32 and R_ARM_PC24 have been
    implemented as these are used by the 4.2.0 CodeSourcery Lite release.

llvm-svn: 271993
2016-06-07 09:31:52 +00:00