Commit Graph

6 Commits

Author SHA1 Message Date
Rafael Espindola b691ccf0a5 Revert "Add terminator to .eh_frame sections"
This reverts commit r296378.

I am pretty sure this is incorrect. In particular, for just

        .cfi_startproc
        nop
        .cfi_endproc

We now add an extra 4 zeros that neither bfd nor gold add.

llvm-svn: 296503
2017-02-28 18:55:08 +00:00
Rui Ueyama 1720ef1343 Add terminator to .eh_frame sections
Patch by Mark Kettenis.

Currenlty ld.lld does not add a terminator (a CIE with its length field
set to zero) to the .eh_frame sections it generates.  While the relevant
standards (the AMD64 SysV ABI and the Linux LSB) are not explicit about
this, such a terminator is expected by some unwinder implementations and
seems to be always emitted by ld.bfd. In addition to that, the Linux LSB

  https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html#EHFRAME

explicitly says that

  The .eh_frame section shall contain 1 or more Call Frame Information
  (CFI) records.

Currently, if the .eh_frame sections of the input files only contain
terminators, ld.lld emits a zero=sized .eh_frame section
which clearly doesn't meet that requirement.

The diff makes sure a terminator gets added to each .eh_frame section
and adjusts all the relevant tests to account for that.  An additional
test isn't needed as these adjustments mean that the existence of the
terminator is tested for by several tests already.

Differential Revision: https://reviews.llvm.org/D30335

llvm-svn: 296378
2017-02-27 20:44:59 +00:00
Ed Maste 8fd0196c6f lld: Default image base address to 0x200000 on x86-64
Align to the large page size (known as a superpage or huge page).
FreeBSD automatically promotes large, superpage-aligned allocations.

Differential Revision:	https://reviews.llvm.org/D27042

llvm-svn: 287782
2016-11-23 17:44:02 +00:00
Rui Ueyama f86cb90a2d Do not propagate section name and attributes to .eh_frame.
.eh_frame is always ".eh_frame" and its attribute is fixed.
No need to copy from inputs to outputs. GNU gold also sets
SHT_PROGBITS.

llvm-svn: 270443
2016-05-23 15:12:41 +00:00
Rafael Espindola 1b6188d2f8 Make this test a bit stronger.
Show that in addition to handling empty .eh_frame, it is merged with any
regular .eh_frame.

llvm-svn: 265588
2016-04-06 19:38:26 +00:00
George Rimar 6ab275c0c8 [ELF] - Fixed handling relocations against zero sized .eh_frame section.
The file crtbeginT.o has relocations pointing to the start of an empty
.eh_frame that is known to be the first in the link. It does that to
identify the start of the output .eh_frame. Handle this special case.

Differential revision: http://reviews.llvm.org/D15610

llvm-svn: 256414
2015-12-25 09:51:42 +00:00