Commit Graph

607 Commits

Author SHA1 Message Date
George Rimar f902250fc1 [LLD][ELF] - Handle quoted strings in the linker scripts correctly.
This is the https://bugs.llvm.org/show_bug.cgi?id=41356,

Seems it is kind of unusual case but it is possible to
have sections that require quotes for their namings.
Like "aaa bbb".

This patch adds support for those.

Differential revision: https://reviews.llvm.org/D60901

llvm-svn: 358874
2019-04-22 07:57:07 +00:00
George Rimar 5f7665969a [LLD][ELF] - Fix mistype. NFC.
Change the tripple name from
aarch64-linux-gnux to -triple=aarch64-linux-gnu

llvm-svn: 358810
2019-04-20 10:50:27 +00:00
George Rimar 55e1987f81 [LLD][ELF] - Convert out-of-order-section-in-region.s to *.test. NFCI.
This is consistent with the our others tests that has large scripts.

llvm-svn: 358659
2019-04-18 12:13:41 +00:00
George Rimar 69186f82f3 [LLD][ELF] - A fix for "linker script assignment loses relative nature of section" bug.
This is https://bugs.llvm.org//show_bug.cgi?id=39857.
I added the comment with much more details to the bug page,
the short version is below.

The following script and code demonstrates the issue:

aliasto__text = __text;
 SECTIONS {
  .text 0x1000 : { __text = . ; *(.text) }
 }
...
call aliasto__text

LLD fails with "cannot refer to absolute symbol: aliasto__text" error.
It happens because at the moment of scanning the relocations
we do not yet assign the correct/final/any section value for the symbol aliasto__text.
I made a change to Relocations.cpp to fix that.

Also, I had to remove the symbol-location.s test case completely, because now it does not
trigger any error. Since now all linker scripts symbols are resolved to constants, no
errors can be triggered at all it seems. I checked that it is consistent with the behavior
of bfd and gold (they do not trigger errors for the case from symbol-location.s), so it should
be OK. I.e. at least it is probably not the best possible, but natural behavior we obtained.

Differential revision: https://reviews.llvm.org/D55423

llvm-svn: 358652
2019-04-18 10:00:37 +00:00
Fangrui Song 3deff86657 [ELF] Respect NonAlloc when copying flags from the previous sections
Summary:
If the output section contains only symbol assignments, we copy flags
from the previous sections. Don't set SHF_ALLOC if NonAlloc is true.

We also have to change the type from SHT_NOBITS to SHT_PROGBITS.
In ld.bfd, bfd_elf_get_default_section_type maps non-alloctable sections to SHT_PROGBITS.
Non-alloctable SHT_NOBITS sections do not make sense.

Fixes PR38626

Differential Revision: https://reviews.llvm.org/D59986

llvm-svn: 358650
2019-04-18 09:22:05 +00:00
George Rimar da49faf15e [LLD][ELF] - Fix the different behavior of the linker script symbols on different platforms.
This generalizes code and also fixes the broken behavior shown in
one of our test cases for some targets, like x86-64.

The issue occurs when the forward declarations are used in the script.
One of the samples is:

SECTIONS {
  foo = ADDR(.text) - ABSOLUTE(ADDR(.text));
};

In that case, we have a broken output when output target does
not use thunks. That happens because thunks creating code
(called from maybeAddThunks)
calls Script->assignAddresses() at least one more time,
what fixups the values. As a result final symbols values can
be different on AArch64 and x86, for example.

In this patch, I generalize and rename maybeAddThunks to
finalizeAddressDependentContent and now it is used and called
by all targets.

Differential revision: https://reviews.llvm.org/D55550

llvm-svn: 358646
2019-04-18 08:15:54 +00:00
Rui Ueyama 14ef9b30b6 lld: elf: Fix sections with explict addresses in regions
Patch by Gabriel Smith.

The address for a section would be evaluated before the region was
switched to. Because of this, the position within the region would not
be updated. After the region is swapped to the dot would be set to the
out of date position within the region, undoing the section address
evaluation.

To fix this, the region is swapped to before the section's address is
evaluated. As part of the fallout of this, expandMemoryRegions needed
to be gated in setDot on the condition that the evaluated address is
less than the dot. This is for the case where sections are not listed
from lowest address to highest address.

Finally, a test for the case where sections are listed "out of order"
was added.

Differential Revision: https://reviews.llvm.org/D60744

llvm-svn: 358638
2019-04-18 02:32:12 +00:00
Fangrui Song abc068fc59 [ELF] Fix typo: .symtab_shndxr -> .symtab_shndx
The typo was introduced to llvm MC in rL204769 (fixed in rL358247) and then to lld.

Also, for relocatable-many-sections.s, the size of .symtab changed at some point and the formula needs update.

llvm-svn: 358248
2019-04-12 02:20:52 +00:00
Rui Ueyama 3a8bb7cd2c Discard debuginfo for object files empty after GC
Patch by Robert O'Callahan.

Rust projects tend to link in all object files from all dependent
libraries and rely on --gc-sections to strip unused code and data.
Unfortunately --gc-sections doesn't currently strip any debuginfo
associated with GC'ed sections, so lld links in the full debuginfo from
all dependencies even if almost all that code has been discarded. See
https://github.com/rust-lang/rust/issues/56068 for some details.

Properly stripping debuginfo for discarded sections would be difficult,
but a simple approach that helps significantly is to mark debuginfo
sections as live only if their associated object file has at least one
live code/data section. This patch does that. In a (contrived but not
totally artificial) Rust testcase linked above, it reduces the final
binary size from 46MB to 5.1MB.

Differential Revision: https://reviews.llvm.org/D54747

llvm-svn: 358069
2019-04-10 10:37:10 +00:00
Fangrui Song e8710ef1fb [ELF] Split RW PT_LOAD on the PT_GNU_RELRO boundary
Summary:
Based on Peter Collingbourne's suggestion in D56828.

Before D56828: PT_LOAD(.data PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) .bss)
Old:           PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) .data .bss)
New:           PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro)) PT_LOAD(.data. .bss)

The new layout reflects the runtime memory mappings.
By having two PT_LOAD segments, we can utilize the NOBITS part of the
first PT_LOAD and save bytes for .bss.rel.ro.

.bss.rel.ro is currently small and only used by copy relocations of
symbols in read-only segments, but it can be used for other purposes in
the future, e.g. if a relro section's statically relocated data is all
zeros, we can move it to .bss.rel.ro.

Reviewers: espindola, ruiu, pcc

Reviewed By: ruiu

Subscribers: nemanjai, jvesely, nhaehnle, javed.absar, kbarton, emaste, arichardson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58892

llvm-svn: 356226
2019-03-15 01:29:57 +00:00
Fangrui Song 07f8daf05e [ELF] Simplify RelRo, TLS, NOBITS section ranks and make RW PT_LOAD start with RelRo
Old: PT_LOAD(.data | PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .bss)
New: PT_LOAD(PT_GNU_RELRO(.data.rel.ro .bss.rel.ro) | .data .bss)

The placement of | indicates page alignment caused by PT_GNU_RELRO. The
new layout has simpler rules and saves space for many cases.

Old size: roundup(.data) + roundup(.data.rel.ro)
New size: roundup(.data.rel.ro + .bss.rel.ro) + .data

Other advantages:

* At runtime the 3 memory mappings decrease to 2.
* start(PT_TLS) = start(PT_GNU_RELRO) = start(RW PT_LOAD). This
  simplifies binary manipulation tools.
  GNU strip before 2.31 discards PT_GNU_RELRO if its
  address is not equal to the start of its associated PT_LOAD.
  This has been fixed by https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f2731e0c374e5323ce4cdae2bcc7b7fe22da1a6f
  But with this change, we will be compatible with GNU strip before 2.31
* Before, .got.plt (non-relro by default) was placed before .got (relro
  by default), which made it impossible to have _GLOBAL_OFFSET_TABLE_
  (start of .got.plt on x86-64) equal to the end of .got (R_GOT*_FROM_END)
  (https://bugs.llvm.org/show_bug.cgi?id=36555). With the new ordering, we
  can improve on this regard if we'd like to.

Reviewers: ruiu, espindola, pcc

Subscribers: emaste, arichardson, llvm-commits, joerg, jdoerfert

Differential Revision: https://reviews.llvm.org/D56828

llvm-svn: 356117
2019-03-14 03:47:45 +00:00
Peter Collingbourne 16d9a0acfd ELF: Change FileSize back to a uint64_t.
This lets us detect file size overflows when creating a 64-bit binary on
a 32-bit machine.

Differential Revision: https://reviews.llvm.org/D58840

llvm-svn: 355218
2019-03-01 18:53:41 +00:00
Peter Collingbourne 7fb9eabda5 ELF: Write .eh_frame_hdr explicitly after writing .eh_frame.
This lets us remove the special case from Writer::writeSections(), and also
fixes a bug where .eh_frame_hdr isn't necessarily written in the correct
order if a linker script moves .eh_frame and .eh_frame_hdr into the same
output section.

Differential Revision: https://reviews.llvm.org/D58795

llvm-svn: 355153
2019-02-28 23:11:35 +00:00
Rui Ueyama 016833bac2 lld: unquote possibly quoted `EXTERN("symbol")` entry in linker script.
gold accepts quoted strings. binutils requires quoted strings for some
kinds of symbols, e.g.:

  it accepts quoted symbols with @ in name:

  $ echo 'EXTERN("__libc_start_main@@GLIBC_2.2.5")' > a.script
  $ g++ a.script
  /usr/lib/gcc/x86_64-redhat-linux/4.8.5/../../../../lib64/crt1.o: In function `_start':
  (.text+0x20): undefined reference to `main'
  collect2: error: ld returned 1 exit status

  but rejects them if unquoted:

  $ echo 'EXTERN(__libc_start_main@@GLIBC_2.2.5)' > a.script
  $ g++ a.script
  a.script: file not recognized: File format not recognized
  collect2: error: ld returned 1 exit status

To maintain compatibility with existing linker scripts support quoted
strings in lld as well.

Patch by Lucian Adrian Grijincu.

Differential Revision: https://reviews.llvm.org/D57987

llvm-svn: 353756
2019-02-11 22:01:32 +00:00
Matt Davis 0d0e9c08a4 [llvm-readobj] Display sections that do not belong to a segment in the section-mapping
Summary:
The following patch adds the "None" line to the section to segment mapping dump.
That line lists the sections that do not belong to any segment.
I realize that this change differs from GNU readelf which does not display the latter information.

I'd rather not add this "feature" under a command line option.  I think that might introduce confusion, since users would have to
make an additional decision as to if they want to see all of the section-to-segment map or just a subset of it.

Another option is to only print the "None" line if the `--section-mapping` option is passed; however,
that might also introduce some confusion, because the section-to-segment map would be different between`--program-headers`
and the `--section-mapping` output.  While the difference is just the "None" line, it seems that if we choose to display
the segment-to-section mapping, then we should always display the whole map including the sections
that do not belong to segments.

```
Section to Segment mapping:
  Segment Sections...
   00
   01     .interp
   02     .interp .note.ABI-tag .gnu.hash
   03     .init_array .fini_array .dynamic
   04     .dynamic
   05     .note.ABI-tag
   06     .eh_frame_hdr
   07
   08     .init_array .fini_array .dynamic .got
   None   .comment .symtab .strtab .shstrtab <--- THIS LINE
```

Reviewers: grimar, rupprecht, jhenderson, espindola

Reviewed By: rupprecht

Subscribers: khemant, emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D57700

llvm-svn: 353217
2019-02-05 21:01:01 +00:00
George Rimar 8bb8433a1a [LLD][ELF] - Update tests after r352366.
r352366 "[llvm-objdump] - Print LMAs when dumping section headers." changed the format of
llvm-objdump output. We have to update the LLD tests.

llvm-svn: 352372
2019-01-28 15:03:47 +00:00
James Henderson b88d6fd7b8 [LLD][ELF]Fix tests for D56910
r351789 changes the output of llvm-readelf --dyn-symbols. This causes 3
LLD tests to break. This patch fixes them.

Reviewed by: ruiu

Differential Revision: https://reviews.llvm.org/D56911

llvm-svn: 351790
2019-01-22 09:35:47 +00:00
George Rimar 6552b29867 [LLD][ELF] - Fix tests after r350840.
D56076 (r350840) changed the llvm-objdump output.

This is a follow up commit to fix LLD test cases.

llvm-svn: 350842
2019-01-10 16:26:05 +00:00
James Henderson 4ba1777a2d [ELF] Remove checking for spurious '@' at the end of dynamic sym names
llvm-readobj currently has a bug (see PR40097) where it prints '@' at
the end of unversioned dynamic symbols. This bug will be fixed in a
separate later commit, but these tests need fixing first.

Reviewed by: ruiu, Higuoxing

Differential Revision: https://reviews.llvm.org/D56388

llvm-svn: 350614
2019-01-08 10:50:59 +00:00
George Rimar 751e6e1cf5 [LLD][ELF] - Report a location for symbols from the linker script when reporting an error.
When we report an error for symbols defined in the linker script,
we do not report the location properly.

For example:

ld.lld: error: relocation R_AARCH64_CALL26 cannot refer to absolute symbol: aliasto__text
>>> defined in <internal>
>>> referenced by rtoabs.o:(.text+0x4)

This patch fixes that.

Differential revision: https://reviews.llvm.org/D55360

llvm-svn: 349612
2018-12-19 10:19:40 +00:00
George Rimar 1f958ed269 [LLD][ELF] - Support discarding the .dynamic section.
This is a part of https://bugs.llvm.org/show_bug.cgi?id=39810.

Seems it turns out that supporting /DISCARD/ for the .dynamic section with the
linker script is something we can do easily. The patch does this.

Differential revision: https://reviews.llvm.org/D55211

llvm-svn: 348749
2018-12-10 09:24:49 +00:00
George Rimar ad667661c4 [ELF] - Allow discarding .dynsym from the linker script.
This is a part of https://bugs.llvm.org/show_bug.cgi?id=39810.
The patch allows discarding the .dynsym section using linker script.

Differential revision: https://reviews.llvm.org/D55218

llvm-svn: 348748
2018-12-10 09:13:36 +00:00
George Rimar 4af28e46ca [LLD][ELF] - Support discarding .dynstr section.
This is a part of https://bugs.llvm.org/show_bug.cgi?id=39810.
The patch allows discarding the .dynstr section using linker script.

Differential revision: https://reviews.llvm.org/D55215

llvm-svn: 348746
2018-12-10 09:07:30 +00:00
George Rimar b3be390f94 [ELF] - (-Map file) Implement printing of LMA for assignments outside of section declarations.
This was a missing piece.
We started to print LMAs and information about assignments,
but did not do that for assignments outside of section declarations yet.
The patch implements it.

Differential revision: https://reviews.llvm.org/D45314

llvm-svn: 348468
2018-12-06 09:04:52 +00:00
George Rimar f49fe218c2 [LLD][ELF] - Linker script: accept using a file name without a list of sections.
This is a part of
https://bugs.llvm.org/show_bug.cgi?id=39885

Linker script specification says:
"You can specify a file name to include sections from a particular file. You would
do this if one or more of your files contain special data that needs to be at a
particular location in memory."

LLD did not accept this syntax. The patch implements it.

Differential revision: https://reviews.llvm.org/D55324

llvm-svn: 348463
2018-12-06 08:34:52 +00:00
Rui Ueyama a592aeb35a ELF: allow non allocated sections to go into allocated sections
Patch from Andrew Kelley.

For context, see https://bugs.llvm.org/show_bug.cgi?id=39862

The use case is embedded / OS programming where the kernel wants
access to its own debug info via mapped dwarf info. I have a proof of
concept of this working, using this linker script snippet:

  .rodata : ALIGN(4K) {
    *(.rodata)
    __debug_info_start = .;
    KEEP(*(.debug_info))
    __debug_info_end = .;
    __debug_abbrev_start = .;
    KEEP(*(.debug_abbrev))
    __debug_abbrev_end = .;
    __debug_str_start = .;
    KEEP(*(.debug_str))
    __debug_str_end = .;
    __debug_line_start = .;
    KEEP(*(.debug_line))
    __debug_line_end =
    .;
    __debug_ranges_start
    = .;
    KEEP(*(.debug_ranges))
    __debug_ranges_end
    = .;
  }

Differential revision: https://reviews.llvm.org/D55276

llvm-svn: 348291
2018-12-04 18:47:44 +00:00
Martell Malone 15b6c453b8 [ELF] Allow discarding of .rela.plt
When linking the linux kernel on ppc64le

ld.lld -EL -m elf64lppc -Bstatic --orphan-handling=warn --build-id -o
.tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --whole-archive
built-in.a --no-whole-archive --start-group lib/lib.a --end-group
ld.lld: error: discarding .rela.plt section is not allowed

The linker script discards with the following matches
*(.glink .iplt .plt .rela* .comment)

Differential Revision: https://reviews.llvm.org/D54871

llvm-svn: 348258
2018-12-04 12:37:56 +00:00
Rui Ueyama 3b6cd2c602 Show a proper error message if output file is too large.
At least on Linux, if a file size given to FileOutputBuffer is greater
than 2^63, it fails with "Invalid argument" error, which is not a
user-friendly error message. With this patch, lld prints out "output
file too large" instead.

llvm-svn: 348153
2018-12-03 17:42:57 +00:00
Jordan Rupprecht 5bd334aef7 [lld][NFC] Update tests to use -S instead of -s when using llvm-readelf.
Summary: llvm-readobj/readelf accepts both -s and -S as aliases for --sections. However with GNU readelf only -S means --section, and -s means --symbols. I would like to make llvm-readelf more compatible.

Reviewers: MaskRay, espindola

Reviewed By: MaskRay

Subscribers: emaste, arichardson, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D54118

llvm-svn: 346164
2018-11-05 20:39:06 +00:00
George Rimar 3608decaa5 [ELF] - Do not crash when -r output uses linker script with `/DISCARD/`
This is https://bugs.llvm.org/show_bug.cgi?id=39493.

We crashed previously because did not handle /DISCARD/ properly
when -r was used. I think it is uncommon to use scripts with -r, though I see
nothing wrong to handle the /DISCARD/ so that we will not crash at least.

Differential revision: https://reviews.llvm.org/D53864

llvm-svn: 345819
2018-11-01 09:20:06 +00:00
Rui Ueyama ea8cd00a1d Add OUTPUT_FORMAT linker script directive support.
This patch adds a support for OUTPUT_FORMAT linker script directive.
Since I'm not 100% confident with BFD names you can use in the directive
for all architectures, I added only a few in this patch. We can add
other names for other archtiectures later.

We still do not support triple-style OUTPUT_FORMAT directive, namely,
OUTPUT_FORMAT(bfdname, big, little). If you pass -EL (little endian)
or -EB (big endian) to the linker, GNU linkers pick up big or little
as a BFD name, correspondingly, so that you can use a single linker
script for bi-endian processor. I'm not sure if we really need to
support that, so I'll leave it alone for now.

Note that -m takes precedence over OUTPUT_FORAMT, but we always parse
a BFD name given to OUTPUT_FORMAT for error checking. You cannot write
an invalid name in the OUTPUT_FORMAT directive.

Differential Revision: https://reviews.llvm.org/D53495

llvm-svn: 344952
2018-10-22 20:50:01 +00:00
Rui Ueyama ae8c3176b8 Fix typo in a test file name.
llvm-svn: 344899
2018-10-22 13:15:19 +00:00
Rui Ueyama 2e9d40d5f4 [lld] Add more complete support for the INCLUDE command.
Patch by Ian Tessier.

This change adds INCLUDE support to the MEMORY and SECTION commands, and
to output sections, as per:

https://sourceware.org/binutils/docs/ld/File-Commands.html#File-Commands

Differential Revision: https://reviews.llvm.org/D52951

llvm-svn: 344368
2018-10-12 17:07:32 +00:00
Peter Collingbourne 6556e6b929 ELF: Don't examine values of linker script symbols during ICF.
These symbols are declared early with the same value, so they otherwise
appear identical to ICF.

Differential Revision: https://reviews.llvm.org/D51376

llvm-svn: 340998
2018-08-29 23:43:38 +00:00
George Rimar a46d08ebe6 [LLD][ELD] - Do not reject INFO output section type when used with a start address.
This is https://bugs.llvm.org/show_bug.cgi?id=38625

LLD accept this: 

".stack (INFO) : {", 

but not this:

".stack address_expression (INFO) :"

The patch fixes it.

Differential revision: https://reviews.llvm.org/D51027

llvm-svn: 340804
2018-08-28 08:39:21 +00:00
George Rimar dffc1911e2 [LLD][ELF] - Add a test for elf::getPriority(StringRef S)
It covers the following line with a test:
https://github.com/llvm-mirror/lld/blob/master/ELF/OutputSections.cpp#L383

llvm-svn: 339348
2018-08-09 15:05:25 +00:00
George Rimar cc8f8194ba [LLD][ELF] - Add a test for ScriptParser::readPhdrType().
This adds a test for https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L1289.

llvm-svn: 339342
2018-08-09 13:19:10 +00:00
George Rimar 5570d7d45b [LLD][ELF] - Add a test for ScriptParser::readOutputSectionDescription.
This covers the following line:
https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L415

llvm-svn: 339333
2018-08-09 12:14:00 +00:00
George Rimar b89367ac46 [LLD][ELF] - Add a test for ScriptParser::readPhdrs(). NFCI.
This covers the following line with a test:
https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L415

llvm-svn: 339327
2018-08-09 11:13:30 +00:00
Rui Ueyama e262bb1afb Add TARGET(foo) linker script directive.
GNU ld's manual says that TARGET(foo) is basically an alias for
`--format foo` where foo is a BFD target name such as elf64-x86-64.

Unlike GNU linkers, lld doesn't allow arbitrary BFD target name for
--format. We accept only "default", "elf" or "binary". This makes
situation a bit tricky because we can't simply make TARGET an alias for
--target.

A quick code search revealed that the usage number of TARGET is very
small, and the only meaningful usage is to switch to the binary mode.
Thus, in this patch, we handle only TARGET(elf.*) and TARGET(binary).

Differential Revision: https://reviews.llvm.org/D48153

llvm-svn: 339060
2018-08-06 21:29:41 +00:00
George Rimar 434341be5b [LLD][ELF] - Fix bug when reporting memory intersections.
rangeToString() takes addres and length,
previously it was called incorrectly.

llvm-svn: 338956
2018-08-04 10:34:52 +00:00
Chris Jackson 1a721eb3a2 [lld] Make tests calling llvm-ar more robust
Some lit tests that call llvm-ar use the 'r' flag. If the target archive
already exists and is in a corrupt state, this can cause the test to fail. We
have added 'rm -f' calls before the llvm-ar calls to increase the
robustness of the tests.

Differential revision: https://reviews.llvm.org/D49184

llvm-svn: 338705
2018-08-02 11:33:54 +00:00
George Rimar acf8cef80f [LLD] Do not overwrite LMAOffset of PT_LOAD header
Patch by Konstantin Schwarz!

If more than a single output section is added to a PT_LOAD header,
only the first section should set the LMAOffset of the segment.
Otherwise, we get a load-address overlap error

Differential revision: https://reviews.llvm.org/D50133

llvm-svn: 338697
2018-08-02 10:45:46 +00:00
George Rimar add69e9c19 [LLD] Only increase LMARegion if different from MemRegion
Patch by Konstantin Schwarz!

If both the MemRegion and LMARegion are set for an output section in
a linker script, we should only increase the LMARegion if it is
different from the MemRegion. Otherwise, we reserve the memory twice.

Differential revision: https://reviews.llvm.org/D50065

llvm-svn: 338684
2018-08-02 08:13:56 +00:00
George Rimar 34bdf27eaa [LLD] - Improve handling of AT> linker script commands
Patch by Konstantin Schwarz!

The condition to create a new phdr must also check the usage of "AT>" 
linker script command, and create a new PT_LOAD header if a new LMARegion is used.

This fixes PR38307

Differential revision: https://reviews.llvm.org/D50052

llvm-svn: 338679
2018-08-02 08:07:07 +00:00
George Rimar 9524dee72e [ELF] - Implement SHT_SYMTAB_SHNDX (.symtab_shndxr) section.
This is relative to https://bugs.llvm.org//show_bug.cgi?id=38119.

SHT_SYMTAB section is able to keep symbols with output section indices
up to 0xff00 (SHN_LORESERVE). But if we have indices that are greater
than that (PR shows that it might happen), we need to use
SHT_SYMTAB_SHNDX extended section. It was not supported by LLD.

Description of the SHT_SYMTAB_SHNDX section is here:
https://docs.oracle.com/cd/E19683-01/817-3677/chapter6-94076/index.html.

Differential revision: https://reviews.llvm.org/D49541

llvm-svn: 338247
2018-07-30 12:39:54 +00:00
Fangrui Song 31cc084619 [ELF] Fix linker-script-in-search-path.s
llvm-svn: 337983
2018-07-25 23:29:15 +00:00
Fangrui Song 7610b4d64c [ELF] Make linker-script-in-search-path.s robust per r337972
llvm-svn: 337975
2018-07-25 22:11:00 +00:00
George Rimar 061af9aafa [ELF] - Add test case for checking PT_INTERP behavior.
When PT_INTERP is specified in PHDRS command, it should be created.
(if other conditions met)

We had no test for the folowing line:
https://github.com/llvm-mirror/lld/blob/master/ELF/LinkerScript.cpp#L1108
And for this header itself.

Patch fixes that.

llvm-svn: 336359
2018-07-05 15:01:44 +00:00
George Rimar 9b99abcf99 [ELF] - Advance position in a memory region when change the Dot.
This is https://bugs.llvm.org//show_bug.cgi?id=37836

Previously LLD could assign to Dot or set the address
for the section with address expression but did not advance
the position in a memory region.

Patch fixes the issue.

llvm-svn: 336335
2018-07-05 10:44:17 +00:00
George Rimar a50054829d [ELF] - Add support for '||' and '&&' in linker scripts.
This is https://bugs.llvm.org//show_bug.cgi?id=37976,
we had no support, but seems someone faced it.

llvm-svn: 336197
2018-07-03 14:02:52 +00:00
James Henderson b427d4eced [ELF] Don't create empty output section for unreferenced PROVIDEs
LLD removes empty output sections otherwise specified in the linker
script. Prior to this change however, if section descriptions included
ANY kind of symbol assignment, then the consequent output section would
not be removed, even if the assignment was marked with PROVIDE and not
actually triggered (i.e. the symbol was never referenced). This change
modifies the isDiscarable function to ignore such directives when
determining whether a section should be discarded, in keeping with
bfd's behaviour. Symbol assignments that do result in a symbol
definition will continue to result in a kept section (this is not
actually the same as bfd's behaviour, but it is simpler, and probably
makes more sense).

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D48771

llvm-svn: 336184
2018-07-03 09:23:25 +00:00
George Rimar 34d2333c07 [ELF] - Revert huge-temporary-file.s changed in r336129
Comment in the test case says that:

## This inputs previously created a 4gb temporarily file under 32 bit
## configuration. Issue was fixed. There is no clean way to check that from here.
## This testcase added for documentation purposes.

The intention of the test was to create such huge file
in case if our code will be broken again.
And currently it documents we do not create huge outputs.

r336129 changed -o to /dev/null and broke the intentions of the test case.

llvm-svn: 336179
2018-07-03 08:30:55 +00:00
Fangrui Song 841ae5ab1e [ELF] Fix other tests after r336129
llvm-svn: 336136
2018-07-02 19:17:03 +00:00
Fangrui Song 40a9f2251b [ELF] Replace unused output filenames with /dev/null in tests
Post commit review at rLLD335992

llvm-svn: 336129
2018-07-02 17:48:23 +00:00
George Rimar 0751a0307a [ELF] - Linker script: add tests for checking malformed numbers parsing.
Previoulsy we had no test that covered malfolmed numbers
with 'H', 'K' and 'M' suffixes, so the following lines
were uncovered:

https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L996
https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L1003
https://github.com/llvm-mirror/lld/blob/master/ELF/ScriptParser.cpp#L1008

Patch fixes that.

llvm-svn: 335979
2018-06-29 14:29:44 +00:00
George Rimar a582419ac7 [ELF] - Implement linker script OVERLAYs.
This is PR36768.

Linker script OVERLAYs are described in 4.6.9. Overlay Description of the spec:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/4/html/Using_ld_the_GNU_Linker/sections.html

They are used to allow output sections which have different LMAs but the same VAs
and used for embedded programming.

Currently, LLD restricts overlapping of sections and that seems to be the most desired
behaviour for defaults. My thoughts about possible approaches for PR36768 are on the bug page,
this patch implements OVERLAY keyword and allows VAs overlapping for sections that within the overlay.

Differential revision: https://reviews.llvm.org/D44780

llvm-svn: 335714
2018-06-27 08:08:12 +00:00
Fangrui Song 3d87323a7e [ELF] Make non-writable non-executable PROGBITS sections closer to .text
This generalizes the old heuristic placing SHT_DYNSYM SHT_DYNSTR first in the readonly SHF_ALLOC segment.

Reviewers: espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D48406

llvm-svn: 335674
2018-06-26 22:13:32 +00:00
Fangrui Song 68fa4e8c34 [ELF] Assign RF_EXEC rank even if --no-rosegment or SECTIONS command is used
Summary:
Currently when --no-rosegment is specified or a linker script with SECTIONS command is used,
.rodata (A) .text (AX) are assigned the same rank and .rodata may be placed after .text .
This increases the gap between .text and .bss and can cause pc-relative relocation overflow (e.g. gcc crtbegin.o crtbegin.S have R_X86_64_PC32 relocation from .text to .bss).

This patch makes SingleRoRx affect only segment layout, not section layout. As a consequence, .rodata will be placed before .text regardless of SingleRoRx.

Reviewers: espindola, ruiu, grimar, echristo, javed.absar

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D48405

llvm-svn: 335627
2018-06-26 17:04:47 +00:00
Fangrui Song 74282efee1 [ELF] Fix sort-non-script.s
llvm-svn: 335499
2018-06-25 17:16:01 +00:00
Fangrui Song 5ea154402e [ELF] Change test files for style consistency. NFC
* Move `REQUIRES:` line to the top
* llvm-mc ... -o %t -> llvm-mc ... -o %t.o
* Don't check "TEXT" "DATA" columns (they are bfd-style names that do
not fit into llvm well) in llvm-objdump output

llvm-svn: 335498
2018-06-25 17:07:40 +00:00
Fangrui Song 65c50074c2 [ELF] readobj -elf-output-style=GNU -> readelf
Style change for consistency. NFC

llvm-svn: 335494
2018-06-25 16:49:52 +00:00
Fangrui Song e737e75491 [ELF] Change llvm-objdump output for D48472: TEXT DATA -> TEXT
Reviewers: jyknight, Bigcheese, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D48473

llvm-svn: 335404
2018-06-23 00:15:23 +00:00
Joel Jones a5752e199c [lld] Add REQUIRES: x86 where needed to tests
If building lld without x86 support, tests that require that support should
be treated as unsupported, not errors.

Tested using:
  1. cmake '-DLLVM_TARGETS_TO_BUILD=AArch64;X86'
     make check-lld
     =>
     Expected Passes    : 1406
     Unsupported Tests  : 287

  2. cmake '-DLLVM_TARGETS_TO_BUILD=AArch64'
     make check-lld
     =>
     Expected Passes    : 410
     Unsupported Tests  : 1283

Patch by Joel Jones

Differential Revision: https://reviews.llvm.org/D47748

llvm-svn: 334095
2018-06-06 13:56:51 +00:00
Rui Ueyama b75d19c36c Make ALIGN work with -r in linker scripts
Patch by Mark Kettenis.

Make ALIGN work in linker scripts used with the -r option. This works in
GNU ld (ld.bfd) and is used to generate the "random gap" object for
linking the OpenBSD kernel.

Differential Revision: https://reviews.llvm.org/D46839

llvm-svn: 332656
2018-05-17 20:22:39 +00:00
Han Shen b56030ee9e [lld] Mitigate relocation overflow [part 1 of 2].
This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC
sections. We do this to mitigate the possibility that huge .dynsym and
.dynstr sections placed between ro-data and text sections cause
relocation overflow.

Differential Revision: https://reviews.llvm.org/D45788

llvm-svn: 332374
2018-05-15 17:02:35 +00:00
George Rimar 4c9ae67bb7 [ELF] - Revert of: r332038, r332054, r332060, r332061, r332062, r332063
This reverts "Mitigate relocation overflow [part 1 of 2]." and the following commits which
were trying to fix the bots.

At the moment of r332082, bots are still failing and we need to find the reason of test case breakages first of all.
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/17042/steps/test/logs/stdio
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/29845/steps/test/logs/stdio

llvm-svn: 332085
2018-05-11 08:11:25 +00:00
Han Shen 6c0881c3cd Mitigate relocation overflow [part 1 of 2].
This CL is to mitigate R_X86_64_PC32 relocation overflow problems for huge binaries that has near 4G allocated sections.

By examining those binaries, there're 2 issues contributes to the problem:
1). huge ".dynsym" and ".dynstr" stands in the way between .rodata and .text
2). _init_array_start/end are placed at 0 if no ".init_array" presents, this causes .text relocation against them become more prone to overflow.

This CL addresses 1st problem (the 2nd will be addressed in another CL.) by assigning a smaller sortrank to .dynsym and .dynstr thus they no longer stand in between.

llvm-svn: 332038
2018-05-10 20:44:42 +00:00
Fangrui Song 95851515d7 Add a CIE with length 0 unconditionally.
Summary: This is not technically required, but glibc unwind-dw2-fde.c classify_object_over_fdes expects there is a CIE record length 0 as a terminator.

Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D46566

llvm-svn: 331708
2018-05-08 01:19:16 +00:00
George Rimar d30a78b3fe [ELF] - Eliminate the AssertCommand.
Currently, LLD supports ASSERT as a separate command.

We support two forms now.

Assign expression-form: . = ASSERT(0x100)
(old GNU ld required it and some scripts in the wild are still using
something like . = ASSERT((_end - _text <= (512 * 1024 * 1024)), "kernel image bigger than KERNEL_IMAGE_SIZE");

Nowadays above is not a mandatory form and command-like form is commonly used:
ASSERT(<expr>, "text);

The return value of the ASSERT is Dot. That was implemented in D30171.
It looks like (2) is just a short version of (1) then.

GNU ld does *not* list ASSERT as a SECTIONS command:
https://sourceware.org/binutils/docs/ld/SECTIONS.html#SECTIONS

Given above we probably can change ASSERT to be an assignment to Dot. 
That makes the rest of the code much simpler. Patch do that.

Differential revision: https://reviews.llvm.org/D45434

llvm-svn: 330814
2018-04-25 11:16:31 +00:00
George Rimar e160473823 [ELF] - Do not crash when trying to order --defsym/linker script symbols.
Currently, we crash because File is null for
such symbols.

Differential revision: https://reviews.llvm.org/D45440

llvm-svn: 329678
2018-04-10 09:44:44 +00:00
George Rimar aeb7e305b8 [ELF] - Simplify test case. NFC.
llvm-svn: 329563
2018-04-09 13:13:36 +00:00
George Rimar 0029f21482 [ELF] - Stop setting OutSecOff too early.
Currently LLD sets OutSecOff in addSection for input sections.
That is a fake offset (just a rude approximation to remember the order), 
used for sorting SHF_LINK_ORDER sections
(see resolveShfLinkOrder, compareByFilePosition).

There are 2 problems with such approach:

1. We currently change and reuse Size field as a value assigned. Changing size is
not good because leads to bugs. Currently, SIZEOF(.bss) for empty .bss returns 2
because we add two empty synthetic sections and increase size twice by 1. 
(See PR37011: https://bugs.llvm.org/show_bug.cgi?id=37011)

2. Such approach simply does not work when --symbol-ordering-file is involved,
because processing of the ordering file might break the initial section order.

This fixes PR37011.

Differential revision: https://reviews.llvm.org/D45368

llvm-svn: 329560
2018-04-09 13:01:50 +00:00
Rui Ueyama 4e150c4c88 Make "Size" column in the map file one characters shorter.
Previously, "size" column is 9 characters long which is too long
at least for 32-bit (because at maximum it needs 8 columns). This
patch make it one column shorter than before. That's also a reasonable
default for 64-bit.

llvm-svn: 329317
2018-04-05 17:20:18 +00:00
Rui Ueyama 16a130bc78 Fix column size in the map file.
Size can be narrow, but LMA should be the same width as VMA.

llvm-svn: 329312
2018-04-05 16:45:37 +00:00
Eugene Leviant 57225ac179 [ELF] Don't add NOLOAD sections to segment
Differential revision: https://reviews.llvm.org/D45264

llvm-svn: 329281
2018-04-05 13:23:59 +00:00
George Rimar e88b76a989 [ELF] - Reveal more information in -Map file about assignments.
Currently, LLD print symbol assignment commands to the map file,
but it does not do that for assignments that are outside of the section
descriptions. Such assignments can affect the layout though.

The patch implements the following:

* Teaches LLD to print symbol assignments outside of section declaration.
* Teaches LLD to print PROVIDE/HIDDEN/PROVIDE hidden commands.

In case when symbol is not provided, nothing will be printed.

Differential revision: https://reviews.llvm.org/D44894

llvm-svn: 329272
2018-04-05 11:25:58 +00:00
George Rimar ee01b1d390 [ELF] - Print LMA in a -Map file.
Currently, LLD prints VA, but not LMA in a map file.
It seems can be useful to print both to reveal layout
details and patch implements it.

Differential revision: https://reviews.llvm.org/D44899

llvm-svn: 329271
2018-04-05 10:51:06 +00:00
George Rimar 1fc9f39bd5 [ELF] - Check that output sections fit in address space.
Added checks to test that we do not produce
output where VA of sections overruns the address
space available.

Differential revision: https://reviews.llvm.org/D43820

llvm-svn: 329063
2018-04-03 12:39:28 +00:00
George Rimar fd11560f6e [ELF] - Linkerscript: support MIN and MAX.
Sample for the OVERLAY command from the spec 
(https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/4/html/Using_ld_the_GNU_Linker/sections.html)
uses MAX command that we do not support currently:

. = 0x1000 + MAX (SIZEOF (.text0), SIZEOF (.text1));

This patch implements support for MIN and MAX.

Differential revision: https://reviews.llvm.org/D44734

llvm-svn: 328696
2018-03-28 11:33:00 +00:00
George Rimar a6ce78ece1 This is PR36799.
Currently, we might have a bug with scripts like below:

.foo : ALIGN(8) 
{
  *(.foo)
} > ram
because do not expand the memory region when doing ALIGN.

This might result in file range overlaps. The patch fixes the issue.

Differential revision: https://reviews.llvm.org/D44730

llvm-svn: 328479
2018-03-26 08:58:16 +00:00
George Rimar d8281379f9 [ELF] - Do not ignore discarding of .rela.plt/.rela.dyn, allow doing custom layout for them.
Currently when we build input sections list in linker script
we ignore all rel[a] sections. That was done to support
scripts like .rela.dyn : { *(.rela.data) } for emit relocs.

Though as a result following scripts were also silently ignored:

/DISCARD/ : { *(.rela.plt)
/DISCARD/ : { *(.rela.dyn)

and we produced output with this sections. That is not ideal.
The solution this patch suggests is simple: do not ignore synthetic
rel[a] sections. That way we can enable common discarding logic
for them and report a proper error.

Differential revision: https://reviews.llvm.org/D41640

llvm-svn: 328419
2018-03-24 13:10:19 +00:00
George Rimar 54634f1990 [ELF] - Another fix for "LLD crashes with --emit-relocs when trying to proccess .eh_frame"
This fixes PR36367 which is about segfault when --emit-relocs is
used together with .eh_frame sections which happens because
of reordering of regular and .rel[a] sections.

Path changes loop that iterates over input sections to create
relocation target sections first.

Differential revision: https://reviews.llvm.org/D44679

llvm-svn: 328299
2018-03-23 09:18:31 +00:00
Rui Ueyama aa92fca83c Fix linker script operator precedence.
"&" should have higher priority than "|" [1]. Previously, they had
the same priority.

[1] https://sourceware.org/binutils/docs/ld/Operators.html

Differential Revision: https://reviews.llvm.org/D43880

llvm-svn: 327684
2018-03-15 23:12:33 +00:00
George Rimar 76f1c78dea [ELF] - Simplify test case. NFCI.
llvm-svn: 327614
2018-03-15 09:26:08 +00:00
George Rimar 84bcabcb86 [ELF] - Show data and assignment commands in the map file.
Patch teaches LLD to print BYTE/SHORT/LONG/QUAD and
location move commands to the map file.

Differential revision: https://reviews.llvm.org/D44004

llvm-svn: 327612
2018-03-15 09:16:40 +00:00
George Rimar 271ed6eb0d [ELF] - Convert overlapping-sections.s testcase to x86 and cleanup.
Patch do the following changes:

* Test case was converted from MIPS to x86.

* Removed part of the test checking we are able to produce a valid output.
  Since we do that already in other tests, this one's intention should be
  only to check we are still able to report overlaps and/or produce
  broken output with overlaps.

Differential revision: https://reviews.llvm.org/D44438

llvm-svn: 327480
2018-03-14 07:44:23 +00:00
George Rimar b9f4b70f20 [ELF} - Fix build bots.
llvm-svn: 327419
2018-03-13 16:23:48 +00:00
George Rimar b7288836ca [ELF] - Fix mistype in comment. NFC.
llvm-svn: 327417
2018-03-13 16:11:02 +00:00
George Rimar f95e7c6f7a [ELF] - Rename test cases to *.test.
This is a follow-up for r327410.

llvm-svn: 327416
2018-03-13 16:02:45 +00:00
George Rimar cfd2c97008 [ELF] - Represent tests as linker scripts instead of asm.
This follows recently started direction and sometimes
allows to fully get rid from `echo` calls.

I'll rename changed files to *.test in a follow-up.

llvm-svn: 327410
2018-03-13 15:47:14 +00:00
George Rimar 796684b451 [ELF] - Implement INSERT BEFORE.
This finishes PR35877.

INSERT BEFORE used similar to INSERT AFTER,
it inserts sections before the given target section.

Differential revision: https://reviews.llvm.org/D44380

llvm-svn: 327378
2018-03-13 09:18:11 +00:00
George Rimar ebc1d1fdde [ELF] - Fix wrong "REQUIRES" in test.
Its a follow up for r327374 to fix BB.

llvm-svn: 327377
2018-03-13 08:50:36 +00:00
George Rimar 2313086726 [ELF] - Restrict section offsets that exceeds file size.
This is part of PR36515.

With some linkerscripts it is possible to get file offset overlaps
and overflows. Currently LLD checks overlaps in checkNoOverlappingSections().
And also we allow broken output with --no-inhibit-exec.
Problem is that sometimes final offset of sections is completely broken
and we calculate output file size wrong and might crash.

Patch implements check to verify that there is no output section
which offset exceeds file size.

Differential revision: https://reviews.llvm.org/D43819

llvm-svn: 327376
2018-03-13 08:47:17 +00:00
George Rimar afbf90aef9 [ELF] - Drop special flags for empty output sections.
This fixes PR36598.

LLD currently crashes when we have empty output section
with SHF_LINK_ORDER flag. This might happen if we place an 
empty synthetic section in the linker script, but keep output
section alive with the use of additional symbol, for example.

The patch fixes the issue by dropping all special flags
for empty sections.

Differential revision: https://reviews.llvm.org/D44376

llvm-svn: 327374
2018-03-13 08:32:56 +00:00
George Rimar e3f198d58a [ELF] - Change consume()->expect() in INSERT AFTER parsing.
AFTER keyword is mandatory and consume() was 
used by mistake here. We accepted broken script before
this patch, testcase shows the issue.

llvm-svn: 327260
2018-03-12 12:34:43 +00:00
George Rimar 9e2c8a9db1 [ELF] - Support "INSERT AFTER" statement.
This implements INSERT AFTER in a following way:

During reading scripts it collects all insert statements.
After we done and read all files it inserts statements into script commands list.

With that:
* Rest of code does know nothing about INSERT.
* Approach is straightforward and have no visible limitations.
* It is also easy to support INSERT BEFORE (was seen in clang code once).
* Should work for PR35877 and similar cases.

Cons:
* It assumes we have "main" scripts that describes sections.

Differential revision: https://reviews.llvm.org/D43468

llvm-svn: 327003
2018-03-08 14:54:38 +00:00
George Rimar bf3c384673 [ELF] - Adjust rangeToString to report ranges in a different format.
It was raised during the review of D43819.

LLD usually use [X, Y] for reporting ranges, like below:
"relocation R_386_16 out of range: 65536 is not in [0, 65535]"

Patch changes rangeToString() to do the same.

Differential revision: https://reviews.llvm.org/D44207

llvm-svn: 326918
2018-03-07 17:54:25 +00:00
George Rimar 527bfd7a48 [ELF] - Recommit r326892,r326893 "[ELF] - Report LMA region overflows."
With fix: add missing "RUN:" prefix to test case.

Original commit message:
We do not report LMA region overflows currently.
Both GNU linkers do that. The patch implements it.

Differential revision: https://reviews.llvm.org/D44094

llvm-svn: 326895
2018-03-07 12:44:18 +00:00
George Rimar 06846c2251 [ELF] - Revert r326892, r326893.
Bots are still unhappy:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/26259

llvm-svn: 326894
2018-03-07 12:33:00 +00:00
George Rimar 64b2ba1f81 [ELF] - Fix build bot after r326892 "[ELF] - Report LMA region overflows."
Removed excessive line from testcase.

llvm-svn: 326893
2018-03-07 12:16:26 +00:00
George Rimar 97e054e00d [ELF] - Report LMA region overflows.
We do not report LMA region overflows currently.
Both GNU linkers do that. The patch implements it.

Differential revision: https://reviews.llvm.org/D44094

llvm-svn: 326892
2018-03-07 11:54:30 +00:00
George Rimar 54baa5f45f [ELF] - Allow discarding .hash and .gnu.hash from linker script.
Currently, LLD segfaults when linker script attempts to discard
one of the hash sections. This patch fixes that.

Differential revision: https://reviews.llvm.org/D44012

llvm-svn: 326891
2018-03-07 11:47:15 +00:00
George Rimar 162d436c8e [ELF] - Support moving location counter when MEMORY is used.
We do not expand memory region correctly for following scripts:

.foo.1 : 
 {
   *(.foo.1)
   . += 0x1000;
 } > ram
Patch generalizes expanding of output sections and memory
regions in one place and fixes the issue.

Differential revision: https://reviews.llvm.org/D43999

llvm-svn: 326688
2018-03-05 10:54:03 +00:00
George Rimar 7b91e2133e [ELF] - Report location for div/mod by zero.
"division by zero" or "modulo by zero" are not
very informative errors and even probably confusing
as does not let to know that error is coming from linker script.
Patch adds location reporting.

Differential revision: https://reviews.llvm.org/D43934

llvm-svn: 326686
2018-03-05 10:02:44 +00:00
George Rimar 97785af464 [ELF] - Report error when memory region is overflowed by data commands.
LLD can not catch a memory area overflow when using a data command.
If we have the script below:

.foo : 
{
  *(.foo)
  BYTE(0x1)
} > ram

where BYTE overflows the ram region, we do not report it currently.
Patch fixes that.

Differential revision: https://reviews.llvm.org/D43948

llvm-svn: 326545
2018-03-02 08:11:58 +00:00
Rafael Espindola e75b42ee4e Don't allocate a header bellow address 0.
With the current code if the script has a PHDRS we always obey and try
to allocate a header. This can cause Min - HeaderSize to underflow.

It looks like bfd actually prints an error for this case. With this
patch we do the same.

Found while looking at pr36515.

llvm-svn: 326441
2018-03-01 15:25:46 +00:00
George Rimar b068b03793 [ELF] - Don't crash on broken MEMORY declaration.
LLD crashes with broken scripts shown in testcase,
because fails to read memory regon name and accesses
MemoryRegions's element which is nullptr.
Patch fixes it.

Differential revision: https://reviews.llvm.org/D43866

llvm-svn: 326431
2018-03-01 12:36:01 +00:00
George Rimar c4df670dea [ELF] - Do not remove empty sections that use symbols in expressions.
This is PR36515.

Currenly if we have a script like .debug_info 0 : { *(.debug_info) },
we would not remove this section and keep it in the output.
That does not work, because it is common case for
debug sections to have a zero address expression.
Patch changes behavior so that we remove only sections
that do not use symbols in its expressions.

Differential revision: https://reviews.llvm.org/D43863

llvm-svn: 326430
2018-03-01 12:27:04 +00:00
George Rimar f3e93b23f7 [ELF] - Fix eh-frame-reloc-out-of-range.test.
Was broken after recent testcases changes.

llvm-svn: 326427
2018-03-01 10:38:51 +00:00
Rui Ueyama 05660daced Convert more tests as linker scripts instead of assembly.
llvm-svn: 326415
2018-03-01 04:21:42 +00:00
Rui Ueyama dc32dc1770 Convert more .s files to linker script files.
Summary:
This change removes large "echo" commands from the test by writing
tests themselves as linker scripts.

Reviewers: rafael

Subscribers: emaste, javed.absar, llvm-commits, arichardson

Differential Revision: https://reviews.llvm.org/D43900

llvm-svn: 326403
2018-03-01 01:19:12 +00:00
Rui Ueyama 2dfe49a441 Write some tests as linker scripts instead of assembly files.
Some linker script test cases contain only a few lines of assembly
and a long linker script. Such tests are easier to maintain if we
write the main test file as a linkier script instead of assembly.

Differential Revision: https://reviews.llvm.org/D43887

llvm-svn: 326363
2018-02-28 20:22:42 +00:00
Rui Ueyama 39ba31ff50 Add "%" operator to the linker script.
This patch improves compatibility with GNU linkers.

Differential Revision: https://reviews.llvm.org/D43883

llvm-svn: 326348
2018-02-28 18:38:13 +00:00
Igor Kudrin c844524e46 [ELF] Process linker scripts deeper when declaring symbols.
We should process symbols inside output section declarations the same way as top-level ones.

Differential Revision: https://reviews.llvm.org/D43008

llvm-svn: 326305
2018-02-28 05:55:56 +00:00
Igor Kudrin 3345c9ac18 [ELF] Create and export symbols provided by a linker script if they referenced by DSOs.
It should be possible to resolve undefined symbols in dynamic libraries
using symbols defined in a linker script.

Differential Revision: https://reviews.llvm.org/D43011

llvm-svn: 326176
2018-02-27 07:18:07 +00:00
Rafael Espindola 79c23eec04 Keep flags from phantom synthetic sections.
This fixes pr36475.

I think this code can be simplified a bit, but I would like to check
in the more direct fix if we are in agreement on the direction and
then refactor.

This is not something that bfd does. The issue is not noticed in bfd
because it keeps fewer sections from the linkerscript in the output.

The reasons why it seems reasonable to do this:

- As George noticed, we would still keep the flags if the output
  section had both an empty synthetic section and a regular section
- We need an heuristic to find the flags of output sections. Using the
  flags of a synthetic section that would have been there seems a
  reasonable heuristic.

llvm-svn: 326137
2018-02-26 22:32:15 +00:00
George Rimar db1a062447 [ELF] - Do not remove empty output sections that are explicitly assigned to phdr in script.
This continues direction started in D43069.

We can keep sections that are explicitly assigned to segment in script.
It helps to simplify code.

Differential revision: https://reviews.llvm.org/D43571

llvm-svn: 325887
2018-02-23 10:53:04 +00:00
George Rimar 3cdf0d969a [ELF] - Report error if removed empty output section declaration used undefined symbols.
This is for fixing PR36297.

Issue itself is that if we have SECTIONS { .bar (a+b) : { *(.stub) } };
script and no section .stub, when LLD will remove .bar, but
produce output with undefined symbols a and b.

Differential revision: https://reviews.llvm.org/D43069

llvm-svn: 325875
2018-02-23 10:15:54 +00:00
George Rimar 4e6f52c9a4 [ELF] - Add testcase documenting flags assigned when empty synthetic section is removed.
This responds to PR36475,

r325763 led to unexprected layout change, though
new behavior seems to be more correct.

Previously we could have following script:

.foo : { *(.foo) } 
.bar : { *(.synthetic_empty) BYTE(0x11) }}
where synthetic_empty is a synthetic section which is empty and
hence removed by linker.

Before r325763 .bar would receive section flags from .synthetic_empty,
but after this revision it receives flags the same as .foo section has.

It is the same as if there would not be any synthetic_empty section in a script,
so looks reasonable and consistent behavior:
.foo : { *(.foo) } 
.bar : { BYTE(0x11) }}

Patch adds testcase to document it.

Differential revision: https://reviews.llvm.org/D43632

llvm-svn: 325873
2018-02-23 09:57:17 +00:00
George Rimar db7c630b01 [ELF] - Simplify testcase. NFC.
This removes script input file and inlines script into
testcase body. That is consistent with othet LS tests
and makes testcase easier to read.

llvm-svn: 325673
2018-02-21 11:56:55 +00:00
Rui Ueyama ff59a899d6 Use toString to print out garbage-collected sections.
Currently, archive file name is missing in this message. In general,
we should avoid constructing strings in an ad-hoc manner and instead
use toString() to get consistent output strings.

Differential Revision: https://reviews.llvm.org/D43420

llvm-svn: 325416
2018-02-17 00:09:49 +00:00
George Rimar 1c08e9f5ce [ELF] - Support COPY, INFO, OVERLAY output sections attributes.
This is PR36298.

(COPY), (INFO), (OVERLAY) all have the same effect:
section should be marked as non-allocatable.

(https://www.eecs.umich.edu/courses/eecs373/readings/Linker.pdf, 
3.6.8.1 Output Section Type)

Differential revision: https://reviews.llvm.org/D43071

llvm-svn: 325331
2018-02-16 10:42:58 +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
George Rimar 308c92b25d [ELF] - Fix BB after r324463.
Test requires arm, but specified x86.

llvm-svn: 324464
2018-02-07 09:41:14 +00:00
George Rimar 3d5e86e5ee [ELF] - Remove unused synthetic sections correctly.
This is PR35740 which now crashes
because we remove unused synthetic sections incorrectly.

We can keep input section description and corresponding output
section live even if it must be empty and dead. 
This results in a crash because SHF_LINK_ORDER handling code
tries to access first section which is nullptr in this case.

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D42681

llvm-svn: 324463
2018-02-07 09:11:07 +00:00
Rui Ueyama 532fa0e1ca Make sure that --no-check-sections doesn't print out warning messages.
Differential Revision: https://reviews.llvm.org/D42988

llvm-svn: 324434
2018-02-07 00:41:34 +00:00
Rui Ueyama 6a8e79b8e5 Add -{no,}-check-sections flags to enable/disable section overlchecking
GNU linkers have this option.

Differential Revision: https://reviews.llvm.org/D42858

llvm-svn: 324150
2018-02-02 22:24:06 +00:00
Rafael Espindola 27b2990d11 Sort each InputSectionDescription individually.
This fixes pr36190.

Thanks to James Henderson for the testcase and for pointing out how to
fix this.

llvm-svn: 323993
2018-02-01 19:30:15 +00:00
Alexander Richardson 6b367faa45 [ELF] Make overlapping output sections an error
Summary:
While trying to make a linker script behave the same way with lld as it did
with bfd, I discovered that lld currently doesn't diagnose overlapping
output sections. I was getting very strange runtime failures which I
tracked down to overlapping sections in the resulting binary. When linking
with ld.bfd overlapping output sections are an error unless
--noinhibit-exec is passed and I believe lld should behave the same way
here to avoid surprising crashes at runtime.

The patch also uncovered an errors in the tests: arm-thumb-interwork-thunk
was creating a binary where .got.plt was placed at an address overlapping
with .got.

Reviewers: ruiu, grimar, rafael

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D41046

llvm-svn: 323856
2018-01-31 09:22:44 +00:00
Rafael Espindola a9f488588d Run dos2unix on another file. NFC.
llvm-svn: 323796
2018-01-30 18:05:56 +00:00
Rafael Espindola c9265e81f4 Run dos2unix in a few files. NFC.
llvm-svn: 323793
2018-01-30 17:24:28 +00:00
Rafael Espindola 22d533568b Sort orphan section if --symbol-ordering-file is given.
Before this patch orphan sections were not sorted.

llvm-svn: 323779
2018-01-30 16:20:08 +00:00
George Rimar c4ccfb5d93 [ELF] - Define linkerscript symbols early.
Currently symbols assigned or created by linkerscript are not processed early
enough. As a result it is not possible to version them or assign any other flags/properties.

Patch creates Defined symbols for -defsym and linkerscript symbols early,
so that issue from above can be addressed.

It is based on Rafael Espindola's version of D38239 patch.

Fixes PR34121.

Differential revision: https://reviews.llvm.org/D41987

llvm-svn: 323729
2018-01-30 09:04:27 +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 db9dd5b43e Improve LMARegion handling.
This fixes the crash reported at PR36083.

The issue is that we were trying to put all the sections in the same
PT_LOAD and crashing trying to write past the end of the file.

This also adds accounting for used space in LMARegion, without it all
3 PT_LOADs would have the same physical address.

llvm-svn: 323449
2018-01-25 17:42:03 +00:00
Benjamin Kramer 3f47fcf102 [ELF] Keep tests from wrinting to the test directory.
llvm-svn: 322943
2018-01-19 14:15:13 +00:00
Rafael Espindola 5e9c77624c Handle parsing AT(ADDR(.foo-bar)).
The problem we had with it is that anything inside an AT is an
expression, so we failed to parse the section name because of the - in
it.

llvm-svn: 322801
2018-01-18 01:14:57 +00:00
George Rimar 0b89c55aea [ELF] - Stop mixing order of -defsym/-script commands.
Previously we always handled -defsym after other commands in command line.
That made impossible to overload values set by -defsym from linker script:

 test.script:            
  foo = 0x22;
-defsym=foo=0x11 -script t.script
would always set foo to 0x11.

That is inconstent with common logic which allows to override command line
options. it is inconsistent with bfd behavior and seems breaks assumption that
-defsym is the same as linker script assignment, as -defsyms always handled out of
command line order.

Patch fixes the handling order.

Differential revision: https://reviews.llvm.org/D42054

llvm-svn: 322625
2018-01-17 10:24:49 +00:00
Rafael Espindola 75702389bd Fix incorrect physical address on self-referencing AT command.
When a section placement (AT) command references the section itself,
the physical address of the section in the ELF header was calculated
incorrectly due to alignment happening right after the location
pointer's value was captured.

The problem was diagnosed and the first version of the patch written
by Erick Reyes.

llvm-svn: 322421
2018-01-12 23:26:25 +00:00
George Rimar 5d01a8be96 [ELF] - Fix for ld.lld does not accept "AT" syntax for declaring LMA region
AT> lma_region expression allows to specify the memory region
for section load address.

Should fix PR35684.

Differential revision: https://reviews.llvm.org/D41397

llvm-svn: 322359
2018-01-12 09:07:35 +00:00
James Henderson e1689689d8 [ELF] Compress debug sections after assignAddresses and support custom layout
Previously, in r320472, I moved the calculation of section offsets and sizes
for compressed debug sections into maybeCompress, which happens before
assignAddresses, so that the compression had the required information. However,
I failed to take account of relocations that patch such sections. This had two
effects:

1. A race condition existed when a debug section referred to a different debug
section (see PR35788).
2. References to symbols in non-debug sections would be patched incorrectly.
This is because the addresses of such symbols are not calculated until after
assignAddresses (this was a partial regression caused by r320472, but they
could still have been broken before, in the event that a custom layout was used
in a linker script).

assignAddresses does not need to know about the output section size of
non-allocatable sections, because they do not affect the value of Dot. This
means that there is no longer a reason not to support custom layout of
compressed debug sections, as far as I'm aware. These two points allow for
delaying when maybeCompress can be called, removing the need for the loop I
previously added to calculate the section size, and therefore the race
condition. Furthermore, by delaying, we fix the issues of relocations getting
incorrect symbol values, because they have now all been finalized.

llvm-svn: 321986
2018-01-08 10:17:03 +00:00
Rafael Espindola 2640a0a5e5 Align SHT_NOBITS sections is they are the first on a PT_LOAD.
We normally want to ignore SHT_NOBITS sections when computing
offsets. The sh_offset of section itself seems to be irrelevant and

- If the section is in the middle of a PT_LOAD, it will make no
  difference on the computed offset of the followup section.

- If it is in the end of a PT_LOAD, we want to avoid its alignment
  changing the offset of the followup sections.

The issue is if it is at the start of the PT_LOAD. In that case we do
have to align it so that the following sections have congruent address
and offset module the page size. We were not handling this case.

This should fix freebsd kernel link.

llvm-svn: 321657
2018-01-02 16:46:30 +00:00
Rafael Espindola 6a97f80755 Fix output section offset and contents when linker script uses memory region and data commands.
Advance the memory region offset when handling a linker script data
command such as BYTE or LONG.  Failure to advance the offset results
in corrupted output with overlapping sections.

Update tests to check for this combination of both a) memory regions
and b) data commands.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35565

Patch by Owen Shaw!

llvm-svn: 321418
2017-12-24 03:46:35 +00:00
Rafael Espindola 9cbb6dd1fc Result of subtracting two symbols should be absolute.
When two linker script symbols are subtracted, the result should be absolute.

This is the behavior of binutils' ld.

Patch by Erick Reyes!

llvm-svn: 321390
2017-12-22 21:55:28 +00:00
Igor Kudrin 5966d15943 [ELF] Fix an assignment command at the end of an .ARM.exidx section.
The value of the symbol in the assignment should include the sentinel entry.

Differential Revision: https://reviews.llvm.org/D41234

llvm-svn: 321154
2017-12-20 08:56:10 +00:00
Rafael Espindola 4e125de4a6 Use # instead of // for comments in a test.
The test was using both // and # before.

llvm-svn: 321049
2017-12-19 00:53:06 +00:00
Peter Smith 96ca4f5e91 [ELF] Remove Duplicate .ARM.exidx sections
The ARM.exidx section contains a table of 8-byte entries with the first
word of each entry an offset to the function it describes and the second
word instructions for unwinding if an exception is thrown from that
function. The SHF_LINK_ORDER processing will order the table in ascending
order of the functions described by the exception table entries. As the
address range of an exception table entry is terminated by the next table
entry, it is possible to merge consecutive table entries that have
identical unwind instructions.

For this implementation we define a table entry to be identical if:
- Both entries are the special EXIDX_CANTUNWIND.
- Both entries have the same inline unwind instructions.
We do not attempt to establish if table entries that are references to
.ARM.extab sections are identical.

This implementation works at a granularity of a single .ARM.exidx
InputSection. If all entries in the InputSection are identical to the
previous table entry we can remove the InputSection. A more sophisticated
but more complex implementation would rewrite InputSection contents so that
duplicates within a .ARM.exidx InputSection can be merged.

Differential Revision: https://reviews.llvm.org/D40967

llvm-svn: 320803
2017-12-15 11:09:41 +00:00
Igor Kudrin f01caab4b7 [ELF] Prevent crash in writing an .ARM.exidx sentinel entry.
We might crash in 'ARMExidxSentinelSection::writeTo()' because it expected
the sentinel entry to be put in the same 'InputSectionDescription' as
the last real entry. This assumption fails if the last output section command
for .ARM.exidx is anything but an input section description, because in this
case 'OutputSection::addSection()' creates a new 'InputSectionDescription'.

Differential Revision: https://reviews.llvm.org/D41105

llvm-svn: 320668
2017-12-14 06:23:50 +00:00
Rui Ueyama 1ce416c635 Remove trailing whitespace.
llvm-svn: 320520
2017-12-12 20:00:30 +00:00