Commit Graph

16 Commits

Author SHA1 Message Date
Daniel Jasper
b7f5b8b4b2 Revert r240302 ("Bring r240130 back.").
This causes errors like:

  ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
  may overflow at runtime; recompile with -fPIC
  blah.cc:function f(): error: undefined reference to ''
  blah.o:g(): error: undefined reference to ''

I have not yet come up with an appropriate reproduction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240394 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 11:31:32 +00:00
Rafael Espindola
afd779f72d Bring r240130 back.
Now that pr23900 is fixed, we can bring it back with no changes.

Original message:

Make all temporary symbols unnamed.

What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 17:52:52 +00:00
Nico Weber
7081f6fc99 Revert 240130, it caused crashes (repro in PR23900).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240193 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 23:43:47 +00:00
Rafael Espindola
ec77d9ad83 Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240130 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 12:16:55 +00:00
Rafael Espindola
a23cc6a1ea Add r224985 back with fixes.
The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.

Original message:

In an assembly expression like

bar:
  .long L0 + 1

the intended semantics is that bar will contain a pointer one byte past L0.

In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.

The solution used in ELF to use relocation with symbols if there is a non-zero
addend.

In MachO before this patch we would just keep all symbols in some sections.

This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.

This patch implements the non-zero addend logic for MachO too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226503 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 21:11:14 +00:00
Rafael Espindola
8327f0bca1 Revert "Add r224985 back with two fixes."
This reverts commit r225644 while I debug a regression.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 19:07:23 +00:00
Rafael Espindola
5512415ade Add r224985 back with two fixes.
One is that AArch64 has additional restrictions on when local relocations can
be used. We have to take those into consideration when deciding to put a L
symbol in the symbol table or not.

The other is that ld64 requires the relocations to cstring to use linker
visible symbols on AArch64.

Thanks to Michael Zolotukhin for testing this!

Remove doesSectionRequireSymbols.

In an assembly expression like

bar:
.long L0 + 1

the intended semantics is that bar will contain a pointer one byte past L0.

In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.

The solution used in ELF to use relocation with symbols if there is a non-zero
addend.

In MachO before this patch we would just keep all symbols in some sections.

This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.

This patch implements the non-zero addend logic for MachO too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225644 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 18:13:07 +00:00
Lang Hames
bce877c84c Revert r225048: It broke ObjC on AArch64.
I've filed http://llvm.org/PR22100 to track this issue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225228 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 00:54:32 +00:00
Rafael Espindola
8093abb745 Add r224985 back with a fix.
The issues was that AArch64 has additional restrictions on when local
relocations can be used. We have to take those into consideration when
deciding to put a L symbol in the symbol table or not.

Original message:

Remove doesSectionRequireSymbols.

In an assembly expression like

bar:
.long L0 + 1

the intended semantics is that bar will contain a pointer one byte past L0.

In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.

The solution used in ELF to use relocation with symbols if there is a non-zero
addend.

In MachO before this patch we would just keep all symbols in some sections.

This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.

This patch implements the non-zero addend logic for MachO too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225048 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 17:19:34 +00:00
Rafael Espindola
937e781f49 Revert "Remove doesSectionRequireSymbols."
This reverts commit r224985.

I am investigating why it made an Apple bot unhappy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225044 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 16:06:48 +00:00
Rafael Espindola
65300b95e6 Remove doesSectionRequireSymbols.
In an assembly expression like

bar:
.long L0 + 1

the intended semantics is that bar will contain a pointer one byte past L0.

In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.

The solution used in ELF to use relocation with symbols if there is a non-zero
addend.

In MachO before this patch we would just keep all symbols in some sections.

This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.

This patch implements the non-zero addend logic for MachO too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224985 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 13:13:27 +00:00
Rafael Espindola
d5dd993855 Simplify test a bit.
It looks like the original intent was to check which symbols were created.
With macho-dump the sections were being checked just to match which symbol
was in which section.

llvm-objdump prints the section a symbol is in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224980 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 05:09:17 +00:00
Rafael Espindola
c1c55ba767 Convert test to FileCheck. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224950 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 19:50:32 +00:00
Hans Wennborg
7fcd5f8c89 MachObjectWriter: optimize the string table for common suffices
This is a follow-up to r207670 (ELF) and r218636 (COFF).

Differential Revision: http://reviews.llvm.org/D5622

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219126 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-06 17:05:19 +00:00
Daniel Dunbar
44fa0473ae macho-dump: Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120185 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-27 04:00:06 +00:00
Daniel Dunbar
d6e59084d0 MC/Mach-O/x86_64: Temporary labels in cstring sections require symbols (and external relocations, but we don't have x86_64 relocations yet).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98583 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-15 21:56:50 +00:00