Commit Graph

68 Commits

Author SHA1 Message Date
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Peter Collingbourne 11dc7fcae2 ELF: Do not ICF two sections with different output sections.
Note that this doesn't do the right thing in the case where there is
a linker script. We probably need to move output section assignment
before ICF to get the correct behaviour here.

Differential Revision: https://reviews.llvm.org/D47241

llvm-svn: 333052
2018-05-23 01:58:43 +00:00
Sam Clegg f187c4d2e5 Consistent use of header file for ICF and MarkLive
Previously wasm used a separate header to declare markLive
and ELF used to declare ICF.  This change makes each backend
consistently declare these in their own headers.

Differential Revision: https://reviews.llvm.org/D43529

llvm-svn: 325631
2018-02-20 22:09:59 +00:00
Igor Kudrin 25f917341e [ELF] Simplify handling of AT section attribute.
This also makes the behavior close to GNU ld's.

Differential Revision: https://reviews.llvm.org/D43284

llvm-svn: 325213
2018-02-15 06:13:52 +00:00
Rafael Espindola a0d7df3988 Put the header in the first PT_LOAD even if that PT_LOAD has a LMAExpr.
This should fix PR36017.

The root problem is that we were creating a PT_LOAD just for the
header. That was technically valid, but inconvenient: we should not be
making the ELF discontinuous.

The solution is to allow a section with LMAExpr to be added to a
PT_LOAD if that PT_LOAD doesn't already have a LMAExpr.

llvm-svn: 323625
2018-01-29 03:44:44 +00:00
Rafael Espindola 4879864dd7 Move LMAOffset from the OutputSection to the PhdrEntry. NFC.
If two sections are in the same PT_LOAD, their relatives offsets,
virtual address and physical addresses are all the same.

I initially wanted to have a single global LMAOffset, on the
assumption that every ELF file was in practiced loaded contiguously in
both physical and virtual memory.

Unfortunately that is not the case. The linux kernel has:

  LOAD           0x200000 0xffffffff81000000 0x0000000001000000 0xced000 0xced000 R E 0x200000
  LOAD           0x1000000 0xffffffff81e00000 0x0000000001e00000 0x15f000 0x15f000 RW  0x200000
  LOAD           0x1200000 0x0000000000000000 0x0000000001f5f000 0x01b198 0x01b198 RW  0x200000
  LOAD           0x137b000 0xffffffff81f7b000 0x0000000001f7b000 0x116000 0x1ec000 RWE 0x200000

The delta for all but the third PT_LOAD is the same:
0xffffffff80000000. I think the 3rd one is a hack for implementing per
cpu data, but we can't break that.

llvm-svn: 323456
2018-01-25 19:02:08 +00:00
Rafael Espindola 9a84f6b954 Detemplate reportDuplicate.
We normally avoid "switch (Config->EKind)", but in this case I think
it is worth it.

It is only executed when there is an error and it allows detemplating
a lot of code.

llvm-svn: 321404
2017-12-23 17:21:39 +00:00
Rafael Espindola 63fcc5cccc Create reserved symbols early so they can be versioned.
This fixes pr35570.

We were creating these symbols after parsing version scripts, so they
could not be versioned.

We cannot move the version script parsing later because we need it for
lto.

One option is to move both addReservedSymbols and
createSyntheticSections earlier. The disadvantage is that some
sections created by createSyntheticSections replace other input
sections. For example, gdb index replaces .debug_gnu_pubnames, so it
wants to run after gc sections so that it can set S->Live to false.

What this patch does instead is to move just the ElfHeader creation
early.

llvm-svn: 320390
2017-12-11 17:23:28 +00:00
George Rimar 78e27e830d [ELF] - Produce relocation section name consistent with output section name when --emit-reloc used with linker script.
This is for "Bug 35474 - --emit-relocs produces wrongly-named reloc sections".

LLD currently for scripts like:

.text.boot : { *(.text.boot) }
emits relocation section with name .rela.text because does not take
redefined name of output section into account and builds section name
using rules for non-scripted case. Patch fixes this oddness.

Differential revision: https://reviews.llvm.org/D40652

llvm-svn: 319526
2017-12-01 09:04:52 +00:00
Simon Atanasyan cfa8aa7edb [MIPS] Set STO_MIPS_MICROMIPS flag and less-significant bit for microMIPS symbols
microMIPS symbols including microMIPS PLT records created for regular
symbols needs to be marked by STO_MIPS_MICROMIPS flag in a symbol table.
Additionally microMIPS entries in a dynamic symbol table should have
configured less-significant bit. That allows to escape teaching a
dynamic linker about microMIPS symbols.

llvm-svn: 318097
2017-11-13 22:40:36 +00:00
Simon Atanasyan f8db45361e [MIPS] Generate thunks for microMIPS code
If symbol has the STO_MIPS_MICROMIPS flag and requires a thunk to perform
call PIC from non-PIC functions, we need to generate a thunk with microMIPS
code.

llvm-svn: 314797
2017-10-03 13:30:02 +00:00
Simon Atanasyan 649e4d328f [MIPS] Fix PLT entries generation in case of linking regular and microMIPS code
Currently LLD calls the `isMicroMips` routine to determine type of PLT entries
needs to be generated: regular or microMIPS. This routine checks ELF
header flags in the `FirstObj` to retrieve type of linked object files.
So if the first file does not contain microMIPS code, LLD will generate
PLT entries with regular (non-microMIPS) code only.

Ideally, if a PLT entry is referenced by microMIPS code only this entry
should contain microMIPS code, if a PLT entry is referenced by regular
code this entry should contain regular code. In a "mixed" case the PLT
entry can be either microMIPS or regular, but each "cross-mode-call" has
additional cost.

It's rather difficult to implement this ideal solution. But we can
assume that if there is an input object file with microMIPS code, the
most part of the code is microMIPS too. So we need to deduce type of PLT
entries based on finally calculated ELF header flags and do not check
only the first input object file.

This change implements this.
  - The `getMipsEFlags` renamed to the `calcMipsEFlags`. The function
    called from the `LinkerDriver::link`. Result is stored in
    the Configuration::MipsEFlags field.
  - The `isMicroMips` and `isMipsR6` routines access the `MipsEFlags`
    field to get and check calculated ELF flags.
  - New types of PLT records created when necessary.

Differential revision: https://reviews.llvm.org/D37747

llvm-svn: 314675
2017-10-02 14:56:41 +00:00
George Rimar 6823c5f0c0 [ELF] - Rename PhdrEntry::First/Last to FirstSec/LastSec. NFC.
As was suggested in D34956 thread.

llvm-svn: 312712
2017-09-07 11:01:10 +00:00
Rui Ueyama 709fb2bb10 Rename ObjectFile -> ObjFile.
Rename it because it was too easy to conflict with llvm::object::ObjectFile
which broke buildbots several times.

llvm-svn: 309199
2017-07-26 22:13:32 +00:00
Rafael Espindola 244ef98161 Detemplate SymbolTable.
NFC, just makes it easier to access from non templated code.

llvm-svn: 309152
2017-07-26 18:42:48 +00:00
Rafael Espindola dc49af9d32 Make a function static. NFC.
llvm-svn: 308939
2017-07-24 23:55:33 +00:00
George Rimar 67c60727ce [ELF] - Apply clang-format. NFC.
llvm-svn: 308297
2017-07-18 11:55:35 +00:00
Rui Ueyama 9e6f268054 Inline a trivial constructor.
llvm-svn: 303958
2017-05-26 02:17:13 +00:00
Rafael Espindola 9e889eb48c Detemplate isRelroSection. NFC.
llvm-svn: 302847
2017-05-11 23:31:06 +00:00
Rafael Espindola 02ed7575e7 Simplify the header allocation.
In the non linker script case we would try very early to find out if
we could allocate the headers. Failing to do that would add extra
alignment to the first ro section, since we would set PageAlign
thinking it was the first section in the PT_LOAD.

In the linker script case the header allocation must be done in the
end, causing some duplication.

We now tentatively add the headers to the first PT_LOAD and if it
turns out they don't fit, remove them. With this we only need to
allocate the headers in one place in the code.

llvm-svn: 302186
2017-05-04 19:34:17 +00:00
George Rimar 2d2621090d [ELF] - Step to combine LinkerScript and LinkerScriptBase
We can move all not templated functionality to LinkerScriptBase.
Patch do that for hasPhdrsCommands() and shows how it helps to detemplate
things in other places.

Probably we should be able to merge these 2 classes into single one after such steps.
Even if not, it still looks as reasonable cleanup for me.

Differential revision: https://reviews.llvm.org/D30895

llvm-svn: 297714
2017-03-14 09:03:53 +00:00
Rafael Espindola 8bb4087f88 Use 32 bits for alignment.
This is consistent with what we do for input sections.

llvm-svn: 297152
2017-03-07 15:51:09 +00:00
Rafael Espindola 24e6f363c5 Merge OutputSectionBase and OutputSection. NFC.
Now that all special sections are SyntheticSections, we only need one
OutputSection class.

llvm-svn: 296127
2017-02-24 15:07:30 +00:00
Rafael Espindola b4c9b81aad Convert InputSectionBase to a class.
Removing this template is not a big win by itself, but opens the way
for removing more templates.

llvm-svn: 295923
2017-02-23 02:28:28 +00:00
Rafael Espindola ecbfd871f9 Don't print DISCARD sections as gced.
This is a small difference I noticed to gold and bfd. When given
--print-gc-sections, we print sections a linkerscript marks
DISCARD. The other linkers don't.

llvm-svn: 295467
2017-02-17 17:35:07 +00:00
Rafael Espindola 0347c0b874 Don't create a bogus PT_PHDR if we don't allocate the headers.
llvm-svn: 292644
2017-01-20 20:46:15 +00:00
Rafael Espindola 8c495e20bd Reduce code duplication when allocating program headers.
This will simplify a bug fix.

llvm-svn: 292642
2017-01-20 20:41:18 +00:00
Rui Ueyama 6e3595d6c5 Move a function defintion to make it static.
llvm-svn: 290215
2016-12-21 00:05:39 +00:00
Rafael Espindola 5967c97323 Fix corner cases of setting the section address.
This handles all the corner cases if setting a section address:

- If the address is too low, we cannot allocate the program headers.
- If the load address is lowered, we have to do that before finalize

This also shares some code with the linker script since it was already
hitting similar cases.

This is used by the freebsd boot loader. It is not clear if we need to
support this with a non binary output, but it is not as bad as I was
expecting.

llvm-svn: 290136
2016-12-19 21:21:07 +00:00
Rafael Espindola 17cb7c0a2a Detemplate PhdrEntry. NFC.
llvm-svn: 290115
2016-12-19 17:01:01 +00:00
Eugene Leviant 84569e6caa [ELF] Refactor target error messages
Differential revision: https://reviews.llvm.org/D27097

llvm-svn: 288114
2016-11-29 08:05:44 +00:00
Rafael Espindola e08e78df6d Make OutputSectionBase a class instead of class template.
The disadvantage is that we use uint64_t instad of uint32_t for some
value in 32 bit files. The advantage is a substantially simpler code,
faster builds and less code duplication.

llvm-svn: 286414
2016-11-09 23:23:45 +00:00
Simon Atanasyan 9e0297b8bc [ELF][MIPS] N32 ABI support
In short the patch introduces support for linking object file conform
MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit
pointer size.

The most non-trivial requirement of this ABI is one more relocation
packing format. N64 ABI puts multiple relocation type into the single
relocation record. The N32 ABI uses series of successive relocations
with the same offset for this purpose. In this patch, new function
`mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to
the N64 relocation so the rest of the code keep unchanged.

For now, linker does not support series of relocations applied to sections
without SHF_ALLOC bit. Probably later I will add the support or insert
some sort of assert into the `relocateNonAlloc` routine to catch this
case.

[1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf

Differential revision: https://reviews.llvm.org/D26298

llvm-svn: 286052
2016-11-05 22:58:01 +00:00
Rafael Espindola 63732f5356 Add a few const qualifiers.
llvm-svn: 285996
2016-11-04 13:20:45 +00:00
Rui Ueyama 55518e7dd8 Consolidate BumpPtrAllocators.
Previously, we have a lot of BumpPtrAllocators, but all these
allocators virtually have the same lifetime because they are
not freed until the linker finishes its job. This patch aggregates
them into a single allocator.

Differential revision: https://reviews.llvm.org/D26042

llvm-svn: 285452
2016-10-28 20:57:25 +00:00
George Rimar a4c7e74d4b [ELF] - Applied clang format. NFC.
llvm-svn: 284705
2016-10-20 08:36:42 +00:00
Rui Ueyama 05384080df Support GNU-style ZLIB-compressed input sections.
Previously, we supported only SHF_COMPRESSED sections because it's
new and it's the ELF standard. But there are object files compressed
in the GNU style out there, so we had to support it.

Sections compressed in the GNU style start with ".zdebug_" and
contain different headers than the ELF standard's one. In this
patch, getRawCompressedData is responsible to handle it.

A tricky thing about GNU-style compressed sections is that we have
to rename them when creating output sections. ".zdebug_" prefix
implies the section is compressed. We need to rename ".zdebug_"
".debug" because our output sections are not compressed.
We do that in this patch.

llvm-svn: 284068
2016-10-12 22:36:31 +00:00
Eugene Leviant a8d12ef853 Do not join sections for relocatable object files
Differential revision: https://reviews.llvm.org/D25232

llvm-svn: 283307
2016-10-05 10:10:45 +00:00
Eugene Leviant 56b21c869e Linker script: implement AT [ (address) ] for PHDR
Differential revision: https://reviews.llvm.org/D24340

llvm-svn: 281024
2016-09-09 09:46:16 +00:00
Simon Atanasyan 85c6b44817 [ELF][MIPS] Support .MIPS.abiflags section
This section supersedes .reginfo and .MIPS.options sections. But for now
we have to support all three sections for ABI transition period.

llvm-svn: 278482
2016-08-12 06:28:49 +00:00
Rui Ueyama 1034c9e342 Remove isOutputDynamic and use Out<ELFT>::DynSymTab instead.
This patch is to not instantiate DynSymTab and DynStrTab if the
output is not a dynamic output.

llvm-svn: 278095
2016-08-09 04:42:01 +00:00
Rui Ueyama 84907c5143 Do not pass the SymbolTable to writeResult.
The SymbolTable is always accessible as Symtab<ELFT>::X,
so no need to pass it as an argument.

llvm-svn: 278091
2016-08-09 03:38:23 +00:00
Rui Ueyama 31f32fa62a Refactor getMipsEFlags.
Previously, we incrementally updated the reuslting flag as we check
file flags, so it was not very clear who is updating what flags.
This patch makes them pure functions -- that has no side effect and
don't update arguments to improve readability.

Now each function construct a patial result, and all resutls are then
bitwise-OR'ed to construct the final result.

This patch also creates a new file, Mips.cpp, to move all these
MIPS functions to a separate file.

Differential Revision: https://reviews.llvm.org/D23249

llvm-svn: 278042
2016-08-08 19:39:45 +00:00
Rafael Espindola 0b113671c5 Make toPhdrFlags a member function. NFC.
llvm-svn: 276868
2016-07-27 14:10:56 +00:00
Rui Ueyama 1b59f27c9a Add `static` to a function that is used only in one file.
llvm-svn: 276774
2016-07-26 17:35:42 +00:00
Rui Ueyama 96bdd5bc81 Do not pass InputFile to reportDiscarded().
Because the file from which an input section is created can be
obtained using getFile().

llvm-svn: 276702
2016-07-25 22:26:28 +00:00
Rui Ueyama fd03cfd27a Instantiate Interp output section only when needed.
This change simplifies interaction between Writer and the linker script
because we can make needsInterpSection() a file-scope function.

llvm-svn: 276261
2016-07-21 11:01:23 +00:00
Rui Ueyama 18f084ff62 Function names should start with lowercase letters.
llvm-svn: 276165
2016-07-20 19:36:41 +00:00
Rafael Espindola 74df5c7eeb Fix build with gcc 6.
llvm-svn: 275972
2016-07-19 12:33:46 +00:00
Eugene Leviant bbe3860244 [ELF] Minimal PHDRS parser and section to segment assignment support
llvm-svn: 275965
2016-07-19 09:25:43 +00:00