Referencing one symbol from another in the same section does not
generally require a relocation. However, the MS linker has a feature
called /INCREMENTAL which enables incremental links. It achieves this
by creating thunks to the actual function and redirecting all
relocations to point to the thunk.
This breaks down with the old scheme if you have a function which
references, say, itself. On x86_64, we would use %rip relative
addressing to reference the start of the function from out current
position. This would lead to miscompiles because other references might
reference the thunk instead, breaking function pointer equality.
This fixes PR21520.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221678 91177308-0d34-0410-b5e6-96231b3b80d8
The ELF symbol `st_other` field might contain additional flags besides
visibility ones. This patch implements support for some MIPS specific
flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221491 91177308-0d34-0410-b5e6-96231b3b80d8
The getBinary and getBuffer method now return ordinary pointers of appropriate
const-ness. Ownership is transferred by calling takeBinary(), which returns a
pair of the Binary and a MemoryBuffer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221003 91177308-0d34-0410-b5e6-96231b3b80d8
Do a better job classifying symbols. This increases the consistency
between the COFF handling code and the ELF side of things.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220952 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This helps llvm-objdump -r to print out the symbol name along
with the relocation type on x86. Adjust existing tests from checking
for "Unknown" to check for the symbol now.
Test Plan: Adjusted test/Object tests.
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5987
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220866 91177308-0d34-0410-b5e6-96231b3b80d8
This CL introduces MachOObjectFile::getUuid(). This function returns an ArrayRef to the object file's UUID, or an empty ArrayRef if the object file doesn't contain an LC_UUID load command.
The new function is gonna be used by llvm-symbolizer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219866 91177308-0d34-0410-b5e6-96231b3b80d8
We, I suppose naïvely, believed the COFF specification with regard to
auxiliary symbol records which defined sections: they specified that the
symbol value should be zero. However, dumpbin and MinGW's objdump do
not consider the symbol value as a restriction. Relaxing this allows us
to properly dump MinGW linked executables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219479 91177308-0d34-0410-b5e6-96231b3b80d8
While getSectionContents was updated to do the right thing,
getSectionSize wasn't. Move the logic to getSectionSize and leverage it
from getSectionContents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219391 91177308-0d34-0410-b5e6-96231b3b80d8
There are two methods in SectionRef that can fail:
* getName: The index into the string table can be invalid.
* getContents: The section might point to invalid contents.
Every other method will always succeed and returning and std::error_code just
complicates the code. For example, a section can have an invalid alignment,
but if we are able to get to the section structure at all and create a
SectionRef, we will always be able to read that invalid alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219314 91177308-0d34-0410-b5e6-96231b3b80d8
After 4 years there is still no normalization library. We do support
disassembly and relocations, so it doesn't look like we need it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219308 91177308-0d34-0410-b5e6-96231b3b80d8
DWARF in COFF utilizes several relocations. Implement support for them
in RelocVisitor to support llvm-dwarfdump.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219280 91177308-0d34-0410-b5e6-96231b3b80d8
output of the llvm-dwarfdump and llvm-objdump report the endianness
used when the object files were generated.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219110 91177308-0d34-0410-b5e6-96231b3b80d8
This patch defines a new iterator for the imported symbols.
Make a change to COFFDumper to use that iterator to print
out imported symbols and its ordinals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218915 91177308-0d34-0410-b5e6-96231b3b80d8
When the flag is given, the command prints out the COFF import table.
Currently only the import table directory will be printed.
I'm going to make another patch to print out the imported symbols.
The implementation of import directory entry iterator in
COFFObjectFile.cpp was buggy. This patch fixes that too.
http://reviews.llvm.org/D5569
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218891 91177308-0d34-0410-b5e6-96231b3b80d8
For biendian targets like ARM and AArch64, it is useful to have the
output of the llvm-dwarfdump and llvm-objdump report the endianness
used when the object files were generated.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218408 91177308-0d34-0410-b5e6-96231b3b80d8
This change fixes the ARM and AArch64 relocation visitors in
RelocVisitor. They were unconditionally assuming the object data are
little-endian. Tests have been added to ensure that the
llvm-dwarfdump utility does not crash when processing big-endian
object files.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218407 91177308-0d34-0410-b5e6-96231b3b80d8
This change replaces the brittle if/else chain of string comparisons
with a switch statement on the detected target triple, removing the
need for testing arbitrary architecture names returned from
getFileFormatName, whose primary purpose seems to be for display
(user-interface) purposes. The visitor now takes a reference to the
object file, rather than its arbitrary file format name to figure out
whether the file is a 32 or 64-bit object file and what the detected
target triple is.
A set of tests have been added to help show that the refactoring processes
relocations for the same targets as the original code.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218406 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit faac033f73.
The test depends on all targets to be enabled in llc in order to pass,
and needs to be rewritten/refactored to not have that dependency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218393 91177308-0d34-0410-b5e6-96231b3b80d8
For biendian targets like ARM and AArch64, it is useful to have the
output of the llvm-dwarfdump and llvm-objdump report the endianness
used when the object files were generated.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218391 91177308-0d34-0410-b5e6-96231b3b80d8
This change fixes the ARM and AArch64 relocation visitors in
RelocVisitor. They were unconditionally assuming the object data are
little-endian. Tests have been added to ensure that the
llvm-dwarfdump utility does not crash when processing big-endian
object files.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218389 91177308-0d34-0410-b5e6-96231b3b80d8
This change replaces the brittle if/else chain of string comparisons
with a switch statement on the detected target triple, removing the
need for testing arbitrary architecture names returned from
getFileFormatName, whose primary purpose seems to be for display
(user-interface) purposes. The visitor now takes a reference to the
object file, rather than its arbitrary file format name to figure out
whether the file is a 32 or 64-bit object file and what the detected
target triple is.
A set of tests have been added to help show that the refactoring processes
relocations for the same targets as the original code.
Patch by Charlie Turner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218388 91177308-0d34-0410-b5e6-96231b3b80d8
This format is simply a regular object file with the bitcode stored in a
section named ".llvmbc", plus any number of other (non-allocated) sections.
One immediate use case for this is to accommodate compilation processes
which expect the object file to contain metadata in non-allocated sections,
such as the ".go_export" section used by some Go compilers [1], although I
imagine that in the future we could consider compiling parts of the module
(such as large non-inlinable functions) directly into the object file to
improve LTO efficiency.
[1] http://golang.org/doc/install/gccgo#Imports
Differential Revision: http://reviews.llvm.org/D4371
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218078 91177308-0d34-0410-b5e6-96231b3b80d8
This finishes the ability of llvm-objdump to print out all information from
the LC_DYLD_INFO load command.
The -bind option prints out symbolic references that dyld must resolve
immediately.
The -lazy-bind option prints out symbolc reference that are lazily resolved on
first use.
The -weak-bind option prints out information about symbols which dyld must
try to coalesce across images.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217853 91177308-0d34-0410-b5e6-96231b3b80d8
Teach WinCOFFObjectWriter how to write -mbig-obj style object files;
these object files allow for more sections inside an object file.
Our support for BigObj is notably different from binutils and cl: we
implicitly upgrade object files to BigObj instead of asking the user to
compile the same file *again* but with another flag. This matches up
with how LLVM treats ELF variants.
This was tested by forcing LLVM to always emit BigObj files and running
the entire test suite. A specific test has also been added.
I've lowered the maximum number of sections in a normal COFF file,
VS "14" CTP 3 supports no more than 65279 sections. This is important
otherwise we might not switch to BigObj quickly enough, leaving us with
a COFF file that we couldn't link.
yaml2obj support is all that remains to implement.
Differential Revision: http://reviews.llvm.org/D5349
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217812 91177308-0d34-0410-b5e6-96231b3b80d8
Similar to my previous -exports-trie option, the -rebase option dumps info from
the LC_DYLD_INFO load command. The rebasing info is a list of the the locations
that dyld needs to adjust if a mach-o image is not loaded at its preferred
address. Since ASLR is now the default, images almost never load at their
preferred address, and thus need to be rebased by dyld.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217709 91177308-0d34-0410-b5e6-96231b3b80d8
This adds support for reading the "bigobj" variant of COFF produced by
cl's /bigobj and mingw's -mbig-obj.
The most significant difference that bigobj brings is more than 2**16
sections to COFF.
bigobj brings a few interesting differences with it:
- It doesn't have a Characteristics field in the file header.
- It doesn't have a SizeOfOptionalHeader field in the file header (it's
only used in executable files).
- Auxiliary symbol records have the same width as a symbol table entry.
Since symbol table entries are bigger, so are auxiliary symbol
records.
Write support will come soon.
Differential Revision: http://reviews.llvm.org/D5259
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217496 91177308-0d34-0410-b5e6-96231b3b80d8
