Commit Graph

16 Commits

Author SHA1 Message Date
Rafael Espindola
930ca98433 Fix pr19645.
The fix itself is fairly simple: move getAccessVariant to MCValue so that we
replace the old weak expression evaluation with the far more general
EvaluateAsRelocatable.

This then requires that EvaluateAsRelocatable stop when it finds a non
trivial reference kind. And that in turn requires the ELF writer to look
harder for weak references.

Last but not least, this found a case where we were being bug by bug
compatible with gas and accepting an invalid input. I reported pr19647
to track it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207920 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-03 19:57:04 +00:00
Rafael Espindola
0a70f9b3b9 Look through variables when computing relocations.
Given

bar = foo + 4
	.long bar

MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.

Fixing this unfortunately required some other changes:

* Since the variable is now evaluated, it would prevent the ELF writer from
  noticing the weakref marker the elf streamer uses. This patch then replaces
  that with a VariantKind in MCSymbolRefExpr.

* Using VariantKind then requires us to look past other VariantKind to see

	.weakref	bar,foo
	call	bar@PLT

  doing this also fixes

	zed = foo +2
	call zed@PLT

  so that is a good thing.

* Looking past VariantKind means that the relocation selection has to use
  the fixup instead of the target.

This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 02:12:01 +00:00
Craig Topper
50bee42b54 Convert assert(0) to llvm_unreachable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149849 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-05 22:14:15 +00:00
Jim Grosbach
82f4ce5081 Add simple support for keeping MCFixup source information.
Can be used to issue more user friendly diagnostics for faulty
relocation constructs and such.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149092 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-26 23:20:11 +00:00
Rafael Espindola
ce618af3e8 Section relative fixups are a coff concept, not a x86 one. Replace the
x86 specific reloc_coff_secrel32 with a generic FK_SecRel_4.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147252 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 14:47:52 +00:00
Akira Hatanaka
84bfc2f090 This patch addresses gp relative fixups/relocations for jump tables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145112 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-23 22:18:04 +00:00
Rafael Espindola
3a83c40ab6 Add support for the same encodings of the personality function that gnu as
supports.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122577 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-27 00:36:05 +00:00
Michael J. Spencer
1f6efa3996 Merge System into Support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120298 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 18:16:10 +00:00
Rafael Espindola
e04ed7e45f Define generic 1, 2 and 4 byte pc relative relocations. They are common
and at least the 4 byte one will be needed to implement the .cfi_* directives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120240 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-28 14:17:56 +00:00
Daniel Dunbar
0dd0c941c9 MC: Simplify MCFixup and increase the available offset size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104698 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-26 15:18:40 +00:00
Daniel Dunbar
2be2fd0730 MCAssembler: Switch MCAsmFixup to storing MCFixupKind instead of just a size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96094 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13 09:28:54 +00:00
Daniel Dunbar
5d5a1e13a1 MC: Switch MCFixup to just hold an MCExpr pointer instead of index into the
MCInst it came from.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95767 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 04:47:08 +00:00
Daniel Dunbar
4c6e18aefe Fix a signed comparison warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95766 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 04:46:51 +00:00
Chris Lattner
37145b6e4c "fixup" a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95754 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 01:46:47 +00:00
Chris Lattner
5d672cfab0 Add ability for MCInstPrinters to add comments for instructions.
Enhance the x86 backend to show the hex values of immediates in
comments when they are large.  For example:

        movl    $1072693248, 4(%esp)    ## imm = 0x3FF00000



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95728 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 00:10:18 +00:00
Daniel Dunbar
73c557458c MC: First cut at MCFixup, for getting fixup/relocation information out of an MCCodeEmitter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95708 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 22:59:55 +00:00