Commit Graph

5 Commits

Author SHA1 Message Date
Rafael Espindola a7c3163cdf Use CIE version 1 for .eh_frame.
According to

http://www.linuxbase.org/betaspecs/lsb/LSB-Core-generic/LSB-Core-generic/ehframechpt.html

we should always use 1.

llvm-svn: 235923
2015-04-27 22:04:24 +00:00
Oliver Stannard cf6bfb1dd0 Revert r221150, as it broke sanitizer tests
llvm-svn: 221151
2014-11-03 12:19:03 +00:00
Oliver Stannard 652ec6ee89 Emit .eh_frame with relocations to functions, rather than sections
When LLVM emits DWARF call frame information, it currently creates a local,
section-relative symbol in the code section, which is pointed to by a
relocation on the .eh_frame section. However, for C++ we emit some functions in
section groups, and the SysV ABI has some rules to make it easier to remove
these sections
(http://www.sco.com/developers/gabi/latest/ch4.sheader.html#section_group_rules):

  A symbol table entry with STB_LOCAL binding that is defined relative to one
  of a group's sections, and that is contained in a symbol table section that is
  not part of the group, must be discarded if the group members are discarded.
  References to this symbol table entry from outside the group are not allowed.

This means that we need to use the function symbol for the relocation, not a
temporary symbol.

There was a comment in the code claiming that the local symbol was used to
avoid creating a relocation, but a relocation must be created anyway as the
code and CFI are in different sections.

llvm-svn: 221150
2014-11-03 12:02:51 +00:00
Oliver Stannard f7693f4c1f Emit DWARF3 call frame information when DWARF3+ debug info is requested
Currently, llvm always emits a DWARF CIE with a version of 1, even when emitting
DWARF 3 or 4, which both support CIE version 3. This patch makes it emit the
newer CIE version when we are emitting DWARF 3 or 4. This will not reduce
compatibility, as we already emit other DWARF3/4 features, and is worth doing as
the DWARF3 spec removed some ambiguities in the interpretation of call frame
information.

It also fixes a minor bug where the "return address" field of the CIE was
encoded as a ULEB128, which is only valid when the CIE version is 3. There are
no test changes for this, because (as far as I can tell) none of the platforms
that we test have a return address register with a DWARF register number >127.

llvm-svn: 211272
2014-06-19 15:39:33 +00:00
Tim Northover 72e122607f AArch64: convert MC-layer test to .s file
The CodeGen aspects of this test are already covered by cfi-frame.ll;
making it an assembly file reduces the risk of incidental changes
affecting the test.

llvm-svn: 180671
2013-04-27 11:56:14 +00:00