According to Microsoft's PE/COFF documentation, a SECREL relocation is
"The 32-bit offset of the target from the beginning of its section". By
my reading, the "from the beginning of its section" implies that the
offset is unsigned.
Change from an assertion to an error, since it's possible to trigger
this condition normally for input files with very large sections, and we
should fail gracefully for those instead of asserting.
Differential Revision: https://reviews.llvm.org/D38020
llvm-svn: 313703
These are emitted for comm symbols in object files, when targeting
a GNU environment.
Alternatively, just ignore them since we already align CommonChunk
to the natural size of the content (up to 32 bytes). That would only
trade away the possibility to overalign small symbols, which doesn't
sound like something that might not need to be handled?
Differential Revision: https://reviews.llvm.org/D36304
llvm-svn: 310871
Also handle overflow correctly in LDR/STR relocations. Even if the
offset range of a 8 byte LDR instruction is 15 bit (even if the immediate
itself is 12 bit) due to a 3 bit shift, only include up to 12 bits of offset
after doing the relocation, by limiting the range of the immediate by the
number of shifted bits.
Differential Revision: https://reviews.llvm.org/D35792
llvm-svn: 309175
Also extend the tests for IMAGE_REL_ARM64_PAGEOFFSET_12L to test
all 8/16/32/64 bit GPR and 8/16/32/64/128 SIMD/FP bit ldr/str variants,
and a ldr with an existing offset.
Differential revision: https://reviews.llvm.org/D35647
llvm-svn: 308631
Fix issues found in existing code, while reviewing other changes.
Change the data type of a variable to uint32_t, to avoid potential issues
with signedness in shifts.
Differential revision: https://reviews.llvm.org/D35646
llvm-svn: 308586
This fixes cases on ARM64 when importing from more than one DLL,
in case the imports from the first DLL ended up unaligned.
When fixing up a IMAGE_REL_ARM64_PAGEOFFSET_12L, which shifts the
offset by the load/store size, check that the shift doesn't discard
any bits. (This would also detect if the import address chunks were
unaligned.)
Differential revision: https://reviews.llvm.org/D35640
llvm-svn: 308585
DWARF debug sections can also contain relocations against symbols in
discared segments. LLD should accept such relocations.
Differential Revision: https://reviews.llvm.org/D35526
llvm-svn: 308315
Summary:
This would have caught the invalid object file I used in my test case in
r307726. The OOB was only caught by ASan later, which is slow and
doesn't work on some platforms. LLD should do some basic input
validation itself. This check isn't perfect, so relocations can reach
OOB by up to seven bytes, but it's better than what we had and probably
cheap.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35371
llvm-svn: 307948
This is enough to link a working hello world executable, with
a call to an imported function, a string constant passed to
the imported function, and loads from a global variable.
Differential Revision: https://reviews.llvm.org/D34964
llvm-svn: 307629
Summary:
In order to do this without switching on the symbol kind multiple times,
I created Defined::getChunkAndOffset and use that instead of
SymbolBody::getRVA in the inner relocation loop.
Now we get the symbol's chunk before switching over relocation types, so
we can test if it has been discarded outside the inner relocation type
switch. This also simplifies application of section relative
relocations. Previously we would switch on symbol kind to compute the
RVA, then the relocation type, and then the symbol kind again to get the
output section so we could subtract that from the symbol RVA. Now we
*always* have an OutputSection, so applying SECREL and SECTION
relocations isn't as much of a special case.
I'm still not quite happy with the cleanliness of this code. I'm not
sure what offsets and bases we should be using during the relocation
processing loop: VA, RVA, or OutputSectionOffset.
Reviewers: ruiu, pcc
Reviewed By: ruiu
Subscribers: majnemer, inglorion, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D34650
llvm-svn: 306566
Summary:
For SECTION relocations against absolute symbols, MSVC emits the largest
output section index plus one. I've implemented that by threading a
global variable through DefinedAbsolute that is filled in by the Writer.
A more library-oriented approach would be to thread the Writer through
Chunk::writeTo and SectionChunk::applyRel*, but Rui seems to prefer
doing it this way.
MSVC rejects SECREL relocations against absolute symbols, but only when
the relocation is in a real output section. When the relocation is in a
CodeView debug info section destined for the PDB, it seems that this
relocation error is suppressed, and absolute symbols become zeros in the
object file. This is easily implemented by checking the input section
from which we're applying relocations.
This should fix errors about __safe_se_handler_table and
__guard_fids_table when linking the CRT and generating a PDB.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34541
llvm-svn: 306071
Summary:
Adds a "Discarded" bool to SectionChunk to indicate if the section was
discarded by COMDAT deduplication. The Writer still just checks
`isLive()`.
Fixes PR33446
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34288
llvm-svn: 305582
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
I thought I fixed the page size, but there were still errors.
This patch also contains fixes for grammatical errors.
Thanks pcc for proofreading!
llvm-svn: 301454
LLD is a multi-threaded program. errs() or outs() are not guaranteed
to be thread-safe (they are actually not).
LLD's message(), log() or error() are thread-safe. We should use them.
llvm-svn: 295787
Summary: When we encouter a relocation type we don't know how to handle, this change causes us to print out the hexadecimal value of the relocation type. This makes troubleshooting a little easier.
Reviewers: ruiu, zturner
Differential Revision: https://reviews.llvm.org/D28576
llvm-svn: 291962
This ports the ELF linker's symbol table design, introduced in r268178,
to the COFF linker.
Differential Revision: http://reviews.llvm.org/D21166
llvm-svn: 289280
Handle this in the exact same way as IMAGE_REL_AMD64_SECREL
and IMAGE_REL_I386_SECREL.
Differential revision: https://reviews.llvm.org/D24608
llvm-svn: 282531
Don't blindly OR in the new value, but clear the existing one, since it can be
nonzero. Read out the existing value before, and add into the desired offset.
(The add is done outside of the applyMOV, to handle potential overflow between
the two.)
Patch by Martin Storsjö!
llvm-svn: 277846
The opcode for the bl branches can initially be F000 F800, i.e.
the J1 and J2 bits are already set. Therefore mask these bits out
before or'ing in the new bits.
Patch by Martin Storsjö!
llvm-svn: 277836
Only live symbols are written to the symbol table. Because isLive()
returned false if dead-stripping was disabled entirely, only
non-COMDAT sections were written to the symbol table. This patch fixes
the issue.
llvm-svn: 247856
This is more convenient than the offset from the start of the file as we
don't have to worry about it changing when we move the output section.
This is a port of r245008 from ELF.
llvm-svn: 245018
This has a few advantages
* Less C++ code (about 300 lines less).
* Less machine code (about 14 KB of text on a linux x86_64 build).
* It is more debugger friendly. Just set a breakpoint on the exit function and
you get the complete lld stack trace of when the error was found.
* It is a more robust API. The errors are handled early and we don't get a
std::error_code hot potato being passed around.
* In most cases the error function in a better position to print diagnostics
(it has more context).
llvm-svn: 244215
I don't remember why I thought that only functions are subject
of garbage collection, but the comment here said so, which is
not correct. Moreover, the code just below the comment does not
do what the comment says -- it handles non-COMDAT, non-function
sections as GC root. As a result, it just handles non-COMDAT
sections as GC root.
This patch cleans that up by removing SectionChunk::isRoot and
use isCOMDAT instead.
llvm-svn: 243700
Windows ARM is the thumb ARM environment, and pointers to thumb code
needs to have its LSB set. When we apply relocations, we need to
adjust the LSB if it points to an executable section.
llvm-svn: 243560
SECREL should sets the 32-bit offset of the target from the beginning
of *target's* output section. Previously, the offset from the beginning
of source's output section was used instead.
SECTION means the target section's index, and not the source section's
index. This patch fixes that issue too.
llvm-svn: 243535
Shoaib Meenai