271 Commits

Author SHA1 Message Date
Logan Chien
a68f166d60 llvm-mc: Fix build breakage caused by r205050.
When LLVM is not built with zlib, nocompression.s will test
for the error message.  But this test case will cause breakage
because the exit code is non-zero.  This commit fix this issue
by adding "not" to the command.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205102 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-29 15:10:22 +00:00
Rafael Espindola
224dbf4aec Completely rewrite ELFObjectWriter::RecordRelocation.
I started trying to fix a small issue, but this code has seen a small fix too
many.

The old code was fairly convoluted. Some of the issues it had:

* It failed to check if a symbol difference was in the some section when
  converting a relocation to pcrel.
* It failed to check if the relocation was already pcrel.
* The pcrel value computation was wrong in some cases (relocation-pc.s)
* It was missing quiet a few cases where it should not convert symbol
  relocations to section relocations, leaving the backends to patch it up.
* It would not propagate the fact that it had changed a relocation to pcrel,
  requiring a quiet nasty work around in ARM.
* It was missing comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205076 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-29 06:26:49 +00:00
David Blaikie
1fc0d63775 Debug Compression: Avoid compression debug_frame for now
Turns out debug_frame does use multiple fragments, so it doesn't
compress correctly with the current approach. Disable compressing it for
now while I figure out what's the best solution for it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205059 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 21:48:31 +00:00
David Blaikie
4a9c2585ab llvm-mc: error when -compress-debug-sections is requested and zlib is not linked
This is a bit of a stab in the dark, since I have zlib on my machine.
Just going to bounce it off the bots & see if it sticks.

Do we have some convention for negative REQUIRES: checks? Or do I just
need to add a feature like I've done here?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205050 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 20:45:24 +00:00
David Blaikie
b91f51161f Only test compression when linked with zlib.
I'll implement error handling and a negative test in both llvm-mc and
Clang soon.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205016 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-28 17:04:53 +00:00
David Blaikie
0a0c4cc56f DebugInfo: Support for compressed debug info sections
1) When creating a .debug_* section and instead create a .zdebug_
   section.
2) When creating a fragment in a .zdebug_* section, make it a compressed
   fragment.
3) When computing the size of a compressed section, compress the data
   and use the size of the compressed data.
4) Emit the compressed bytes.

Also, check that only if a section has a compressed fragment, then that
is the only fragment in the section.

Assert-fail if the fragment's data is modified after it is compressed.

Initial review on llvm-commits by Eric Christopher and Rafael Espindola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204958 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 20:45:58 +00:00
Rafael Espindola
e459f72ee0 Correctly propagates st_size.
This also finally removes a bogus call to AliasedSymbol.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204883 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-27 00:28:24 +00:00
Rafael Espindola
3008f80562 Correctly detect if a symbol uses a reserved section index or not.
The logic was incorrect for variables, causing them to end up in the wrong
section if the section had an index >= 0xff00.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204771 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-26 00:16:43 +00:00
Rafael Espindola
81c66bcc13 Create .symtab_shndxr only when needed.
We need .symtab_shndxr if and only if a symbol references a section with an
index >= 0xff00.

The old code was trying to figure out if the section was needed ahead of time,
making it a fairly dependent on the code actually writing the table. It was
also somewhat conservative and would create the section in cases where it was
not needed.

If I remember correctly, the old structure was there so that the sections were
created in the same order gas creates them. That was valuable when MC's support
for ELF was new and we tested with elf-dump.py.

This patch refactors the symbol table creation to another class and makes it
obvious that .symtab_shndxr is really only created when we are about to output
a reference to a section index >= 0xff00.

While here, also improve the tests to use macros. One file is one section
short of needing .symtab_shndxr, the second one has just the right number.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204769 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-25 23:44:25 +00:00
Rafael Espindola
2236f9348d Teach llvm-readobj to print human friendly description of reserved sections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204584 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-24 05:00:34 +00:00
Rafael Espindola
0259b8e14f Add back tests that were reverted in r204203.
They pass again with the fix in r204581.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204582 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-24 03:48:15 +00:00
Rafael Espindola
0bce3343cc Propagate section from base to derived symbol.
We were already propagating the section in

a = b

With this patch we also propagate it for

a = b + 1

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204581 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-24 03:43:21 +00:00
Rafael Espindola
4ff2dadebe Propagate types from symbol to aliases.
This is similar, but not identical to what gas does. The logic in MC is to just
compute the symbol table after parsing the entire file. GAS is mixed, given

.type b, @object
a = b
b:
.type b, @function

It will propagate the change and make 'a' a function. Given

.type b, @object
b:
a = b
.type b, @function

the type of 'a' is still object.

Since we do the computation in the end, we produce a function in both cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204555 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-23 03:33:20 +00:00
Rafael Espindola
a60f719c8d Fix the value computation in
sym_a:
sym_d = sym_a + 1

This is the smallest fix I was able to extract from what got reverted in
r204203.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204527 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-21 22:00:29 +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
Rafael Espindola
94ec09ae32 Make the test harder by using a non-zero offset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204205 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-19 00:26:58 +00:00
Rafael Espindola
025e94d7dc Revert "Add back r203962, r204028 and r204059."
This reverts commit r204178.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204203 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-19 00:13:43 +00:00
Rafael Espindola
4af106a677 Add back r203962, r204028 and r204059.
This reverts commit r204137.

This includes a fix for handling aliases of aliases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 20:40:38 +00:00
Alexander Kornienko
8a99824c5a Revert r203962 and two revisions depending on it: r204028 and r204059.
The revision I'm reverting breaks handling of transitive aliases. This blocks us
and breaks sanitizer bootstrap:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/2651
(and checked locally by Alexey).

This revision is the result of:

  svn merge -r204059:204058 -r204028:204027 -r203962:203961 .

+ the regression test added to test/MC/ELF/alias.s

Another way to reproduce the regression with clang:
  $ cat q.c
  void a1();
  void a2() __attribute__((alias("a1")));
  void a3() __attribute__((alias("a2")));
  void a1() {}

  $ ~/work/llvm-build/bin/clang-3.5-good -c q.c && mv q.o good.o && \
      ~/work/llvm-build/bin/clang-3.5-bad -c q.c && mv q.o bad.o && \
      objdump -t good.o bad.o

    good.o:     file format elf64-x86-64

    SYMBOL TABLE:
    0000000000000000 l    df *ABS*  0000000000000000 q.c
    0000000000000000 l    d  .text  0000000000000000 .text
    0000000000000000 l    d  .data  0000000000000000 .data
    0000000000000000 l    d  .bss   0000000000000000 .bss
    0000000000000000 l    d  .comment       0000000000000000 .comment
    0000000000000000 l    d  .note.GNU-stack        0000000000000000 .note.GNU-stack
    0000000000000000 l    d  .eh_frame      0000000000000000 .eh_frame
    0000000000000000 g     F .text  0000000000000006 a1
    0000000000000000 g     F .text  0000000000000006 a2
    0000000000000000 g     F .text  0000000000000006 a3



    bad.o:     file format elf64-x86-64

    SYMBOL TABLE:
    0000000000000000 l    df *ABS*  0000000000000000 q.c
    0000000000000000 l    d  .text  0000000000000000 .text
    0000000000000000 l    d  .data  0000000000000000 .data
    0000000000000000 l    d  .bss   0000000000000000 .bss
    0000000000000000 l    d  .comment       0000000000000000 .comment
    0000000000000000 l    d  .note.GNU-stack        0000000000000000 .note.GNU-stack
    0000000000000000 l    d  .eh_frame      0000000000000000 .eh_frame
    0000000000000000 g     F .text  0000000000000006 a1
    0000000000000000 g     F .text  0000000000000006 a2
    0000000000000000 g       .text  0000000000000000 a3




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204137 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-18 10:36:11 +00:00
Rafael Espindola
9fdf9d2a1e Consider the base pointer for setting the symbol type.
This is really a consistency fix. Since given

a = b

we propagate the information, we should propagate it too given

a = b + (1 - 1)

Fixes pr19145.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204028 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-17 04:29:51 +00:00
Rafael Espindola
54e582179f Correctly handle an ELF symbol defined with "a = b + expr".
We were marking the symbol as absolute instead of computing b's offset + the
expression value.

This fixes pr19126.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203962 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-14 20:09:04 +00:00
Anders Waldenborg
1410f7ffc6 Add support for assigning to . in AsmParser.
This is implemented by handling assignments to the '.' pseudo symbol
as ".org" directives.

Differential Revision: http://llvm-reviews.chandlerc.com/D2625



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201530 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-17 20:48:32 +00:00
Nico Rieck
268e96a8a6 Fix broken CHECK lines
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201479 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-16 07:31:05 +00:00
Diego Novillo
837c54fa7b Support DWARF discriminators in object streamer.
Summary:
This adds support for emitting DWARF path discriminator values in
the object streamer. It also changes the DWARF dumper to show
discriminator values in the line table output.

Reviewers: echristo

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2794

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201427 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-14 19:27:53 +00:00
David Majnemer
0fd23cd6c2 MC: Add support for .cfi_startproc simple
This commit allows LLVM MC to process .cfi_startproc directives when
they are followed by an additional `simple' identifier. This signals to
elide the emission of target specific CFI instructions that would
normally occur initially.

This fixes PR16587.

Differential Revision: http://llvm-reviews.chandlerc.com/D2624


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200227 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-27 17:20:25 +00:00
David Majnemer
ce5f07f33c Forgot to add testcase for r198590
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199765 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-21 20:39:11 +00:00
Roman Divacky
edc4b60fca Force emit a relocation for @gnu_indirect_function symbols so that the indirect
resolution works.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198780 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-08 18:50:32 +00:00
David Woodhouse
38b362617c [x86] Support R_386_PC8, R_386_PC16 and R_X86_64_PC8
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198763 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-08 12:58:40 +00:00
Roman Divacky
7e889af768 In the ELFWriter when writing aliased (.set) symbols dont blindly
take type from the new symbol but merge them so that the type
is never "downgraded".

This is probably quite rare, except for IFUNC symbols which
we used to misassemble, losing the IFUNC type.

Fixes #18372.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198706 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 20:17:03 +00:00
Alp Toker
087ab613f4 Correct word hyphenations
This patch tries to avoid unrelated changes other than fixing a few
hyphen-related ambiguities and contractions in nearby lines.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196471 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-05 05:44:44 +00:00
NAKAMURA Takumi
688aa71e35 Move llvm/test/MC/ELF/thumb-st_other.s to test/MC/ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196457 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-05 02:21:44 +00:00
Logan Chien
175fe68393 [mc] Fix ELF st_other flag.
ELF_Other_Weakref and ELF_Other_ThumbFunc seems to be LLVM
internal ELF symbol flags.  These should not be emitted to
object file.

This commit defines ELF_STO_Shift for the target-defined
flags for st_other, and increase the value of
ELF_Other_Shift to 16.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196440 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-05 00:34:11 +00:00
Tom Roeder
4ca9a2a0ad This commit adds some (but not all) of the x86-64 relocations that are not
currently supported in the ELF object writer, along with a simple test case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193709 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-30 18:47:25 +00:00
Joerg Sonnenberger
72580780a9 Move the STT_FILE symbols out of the normal symbol table processing for
ELF. They can overlap with the other symbols, e.g. if a source file
"foo.c" contains a function "foo" with a static variable "c".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193569 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-29 01:06:17 +00:00
David Blaikie
2b3ea3cdad MC: Support multiple sections with the same name in the same comdat group
Code review by Eric Christopher and Rafael Espindola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193209 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-22 23:41:52 +00:00
Peter Collingbourne
e52fac1632 Emit DWARF line entries for all data in the instruction stream.
r182712 attempted to do this, but it failed to handle data emitted via
EmitBytes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193041 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-20 02:16:18 +00:00
Hans Wennborg
22f9dd4591 MC asm parser: allow ?'s in symbol names, and handle @'s in names in MS asm
This is another (final?) stab at making us able to parse our own asm output
on Windows.

Symbols on Windows often contain @'s and ?'s in their names. Our asm parser
didn't like this. ?'s were not allowed, and @'s were intepreted as trying to
reference PLT/GOT/etc.

We can't just add quotes around the bad names, since e.g. for MinGW, we use gas
to assemble, and it doesn't like quotes in some places (notably in .def
directives).

This commit makes us allow ?'s in symbol names, and @'s in symbol names for MS
assembly.

Differential Revision: http://llvm-reviews.chandlerc.com/D1978

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193000 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-18 20:46:28 +00:00
Venkatraman Govindaraju
83ba58e5f0 Implements parsing and emitting of .cfi_window_save in MC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191431 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-26 14:49:40 +00:00
David Majnemer
7d7db75a55 X86: Use R_X86_64_TPOFF64 for FK_Data_8
Summary:
LLVM would crash when trying to come up with a relocation type for
assembly like:
movabsq $V@TPOFF, %rax

Instead, we say the relocation type is R_X86_64_TPOFF64.

Fixes PR17274.

Reviewers: dblaikie, nrieck, rafael

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1717

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191163 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-22 05:30:16 +00:00
David Majnemer
60c81c9397 ELF: Parse types in directives like binutils gas
Allow binutils .type and .section directives to take the following
forms:
- @<type>
- %<type>
- "<type>"


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191134 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-21 05:25:12 +00:00
Benjamin Kramer
766f25306a ELF: Add support for the exclude section bit for gas compat.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190769 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-15 19:53:20 +00:00
David Majnemer
bcd9b3b6b1 MC: Add support for '?' flags in .section directives
Summary:
The '?' flag uses the last section group if the last had a section
group.  We treat combining an explicit section group and the '?' as a
hard error.

This fixes PR17198.

Reviewers: rafael, bkramer

Reviewed By: bkramer

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1686

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190768 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-15 19:24:16 +00:00
Daniel Dunbar
24ec2e5a72 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188513 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 00:37:11 +00:00
Rafael Espindola
0a69bac396 Check for $PWD in llvm::sys::current_path.
Some users (clang, libTooling) require this. After this patch we can remove
the calls to getenv("PWD") from clang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188125 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-10 00:50:57 +00:00
Tim Northover
f5b1c5043d Put ELF COMDAT relocations into the relevant COMDAT group.
Patch from Игорь Пашев  (I do hope we support utf-8 commit messages; I
also hope he'll forgive me for transliterating it as Igor Pashev in
case things go horribly wrong).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186034 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-10 20:58:17 +00:00
Serge Pavlov
f04f8b4f77 Added the test missed from r185080.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185316 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-01 09:02:33 +00:00
David Blaikie
c084c0945b Integrate Assembler: Support X86_64_DTPOFF64 relocations
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185131 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-28 04:24:32 +00:00
Ulrich Weigand
4df4bccc71 [MC/DWARF] Generate multiple .debug_line entries for adjacent .loc directives
The compiler occasionally generates multiple .loc directives in a row
(at the same instruction address).  These need to be transformed into
multple actual .debug_line table entries, since they are used to signal
certain information to the debugger (e.g. if the opening brace of a
function body is on the same line as the declaration).

The MCAsmStreamer version of EmitDwarfLocDirective handles this
correctly by emitting a .loc directive every time it is called.
However, the MCObjectStream version simply defaults to recording
the information and emitting only a single table entry later,
e.g. when EmitInstruction is called.

This patch introduces a MCAsmStreamer::EmitDwarfLocDirective
version that emits a line table entry for a .loc directive
that may already be pending before recording the new directive.
(This is similar to how this is handled in GNU as.)

With this patch (and the code alignment factor patch) applied,
I'm now getting identical DWARF .debug sections for all test-suite
object files on PowerPC for the internal and the external assembler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184357 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 21:27:27 +00:00
Rafael Espindola
c9f2cc7e05 Don't hide the first ELF symbol.
The first symbol on ELF is dummy, but it has a defined content and readelf
normally displays it. With this change llvm-readobj also displays it and we
can check that llvm-mc output is correct according to the standard.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183337 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-05 20:33:54 +00:00
Rafael Espindola
7486d92a6c Change how we iterate over relocations on ELF.
For COFF and MachO, sections semantically have relocations that apply to them.
That is not the case on ELF.

In relocatable objects (.o), a section with relocations in ELF has offsets to
another section where the relocations should be applied.

In dynamic objects and executables, relocations don't have an offset, they have
a virtual address. The section sh_info may or may not point to another section,
but that is not actually used for resolving the relocations.

This patch exposes that in the ObjectFile API. It has the following advantages:

* Most (all?) clients can handle this more efficiently. They will normally walk
all relocations, so doing an effort to iterate in a particular order doesn't
save time.

* llvm-readobj now prints relocations in the same way the native readelf does.

* probably most important, relocations that don't point to any section are now
visible. This is the case of relocations in the rela.dyn section. See the
updated relocation-executable.test for example.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182908 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-30 03:05:14 +00:00