This doesn't compile with MSVC 2013:
include\lld/ReaderWriter/PECOFFLinkingContext.h(356) : error C2797:
'lld::PECOFFLinkingContext::_imageVersion': list initialization
inside member initializer list or non-static data member initializer
is not implemented
include\lld/ReaderWriter/PECOFFLinkingContext.h(357) : error C2797:
'lld::PECOFFLinkingContext::_imageVersion': list initialization
inside member initializer list or non-static data member initializer
is not implemented
llvm-svn: 234676
I believe this patch eliminates all remaining uses of _context
or _linkingContext variable names. Consistent naming improves
readability.
llvm-svn: 234645
This patch defines implicit conversion between integers and PowerOf2
instances, so uses of the classes is now implicit and look like
regular integers. Now we are ready to remove the scaffolding.
llvm-svn: 233245
This patch is to make instantiation and conversion to an integer explicit,
so that we can mechanically replace all occurrences of the class with
integer in the next step.
Now get() returns an alignment value rather than its log2 value.
llvm-svn: 233242
of the vector. For a vector 'v', '&v[v.size()]' isn't a valid way to
compute a pointer one-past-the-end of the vector. Instead, write the
loop in terms of iterators and save the beginning iterator. Once we have
that we can compute the beginning pointer from the beginning iterator,
and compute the distance which we should increment the beginning pointer
by subtracting the iterators.
What might be simpler would be to convert the function accepting a raw
pointer for begin and end to accept iterators or a range or some other
construct, but I wanted to keep this to a minimal bug-fix change.
This fixes a crash on any debug STL implementation which checks for
indexing out of bounds.
llvm-svn: 231765
If an output is large, its base relocation section can be also large.
For example, chrome.dll is almost 300 MB, and it has about 9 million
base relocations. Creating the section took 1.5 seconds on my machine.
This patch changes the way to create the section so that we can use
parallel_sort to group base relocations by high bits. This change
makes the linker almost 4% faster for the above test case on my machine.
If I replace parallel_sort with std::sort, performance remains the same,
so single thread performance should remain the same.
This has no functionality change. The output should be identical as
before.
llvm-svn: 231585
Previously applying 1 million relocations took about 2 seconds on my
Xeon 2.4GHz 8 core workstation. After this patch, it takes about 300
milliseconds. As a result, time to link chrome.dll becomes 23 seconds
to 21 seconds.
llvm-svn: 231454
Nothing wrong with reinterpret_cast<llvm::support::ulittle32_t *>(loc),
but that's redundant and not great from readability point of view.
The new functions are wrappers for that kind of reinterpet_casts.
Surprisingly or unsurprisingly, there was no use of big endian read
and write. {read,write}{16,32,64}be have no user. But I think they
still worth to be there in the header for completeness.
http://reviews.llvm.org/D7927
llvm-svn: 230725
This is yet another edge case of base relocation for symbols. Absolute
symbols are in general not target of base relocation because absolute
atom is a way to point to a specific memory location. In r229816, I
removed entries for absolute atoms from the base relocation table
(so that they won't be fixed by the loader).
However, there was one exception -- ImageBase. ImageBase points to the
start address of the current image in memory. That needs to be fixed up
at load time. This patch is to treat the symbol in a special manner.
llvm-svn: 229961
Previously we wrongly emitted a base relocation entry for an absolute symbol.
That made the loader to rewrite some instruction operands with wrong values
only when a DLL is not loaded at the default address. That caused a
misterious crash of some executable.
Absolute symbols will of course never change value wherever the binary is
loaded to memory. We shouldn't emit base relocations for absolute symbols.
llvm-svn: 229816
If the name field of a symbol table entry is all zero, it's interpreted
as it's pointing to the beginning of the string table. The first four
bytes of the string table is the size field, so dumpbin dumps that number
as an ASCIZ string.
This patch fills a dummy value to name field.
llvm-svn: 228971
The dumpbin tool in the MSVC toolchain cannot handle an executable created
by LLD if the executable contains a long section name.
In PE/COFF, a section name is stored to a section table entry. Because the
section name field in the table is only 8 byte long, a name longer than
that is stored to the string table and the offset in the string table is
stored to the section table entry instead.
In order to look up a string from the string table, tools need to handle
the symbol table, because the string table is defined as it immediately
follows the symbol table.
And seems the dumpbin doesn't like zero-length symbol table.
This patch teaches LLD how to emit a dummy symbol table. The dummy table
has one dummy entry in it.
llvm-svn: 228900
Previously, we incorrectly added the image base address to an absolute
symbol address (that calculation doesn't make any sense) if an
IMAGE_REL_I386_DIR32 relocation is applied to an absolute symbol.
This patch fixes the issue. With this fix, we can link Bochs using LLD.
(Choosing Bochs has no special meaining -- I just picked it up as a
test program and found it didn't work.) This also fixes one of the
issues we currently have to link Chromium using LLD.
llvm-svn: 228279
Before this patch there was a cyclic dependency between lldCore and
lldReaderWriter. Only lldConfig could be built as a shared library.
* Moved Reader and Writer base classes into lldCore.
* The following shared libraries can now be built:
lldCore
lldYAML
lldNative
lldPasses
lldReaderWriter
Differential Revision: http://reviews.llvm.org/D7105
From: Greg Fitzgerald <garious@gmail.com>
llvm-svn: 226732
Generalise the base relocation handling slightly to support multiple base
relocation types in PE/COFF. This is necessary to generate proper executables
for WoA.
Track the base relocation type from the decision that we need a base relocation
to the point where we emit the base relocation into base relocation directory.
Remove an outdated TODO item while in the area.
llvm-svn: 226335
The target may be a synthetic symbol like __ImageBase. cast_or_null will ensure
that the atom is a DefinedAtom, which is not guaranteed, which was the original
reason for the cast_or_null. Switch this to dyn_cast, which should enable
building of executables for WoA. Unfortunately, the issue of missing base
relocations still needs to be investigated.
llvm-svn: 226246
This adds the ability to export symbols from a DLL built for ARMNT. Add this
support first to help work towards adding support for import thunks on Windows
on ARM. In order to generate the exports, add support for
IMAGE_REL_ARM_ADDR32NB relocations.
llvm-svn: 225339
ARM NT assumes a purely THUMB execution, and as such requires that the address
of entry point is adjusted to indicate a thumb entry point. Unconditionally
adjust the AddressOfEntryPoint in the PE header for PE/COFF ARM as we only
support ARM NT at the moment.
llvm-svn: 225139
ARM NT assumes a THUMB only environment. As such, any address that is detected
as residing in an executable section is adjusted to have its bottom bit set to
indicate THUMB in case of a mode exchange.
Although the testing here seems insufficient (missing the negative cases) the
existing test cases for the IMAGE_REL_ARM_{ADDR32,MOV32T} are relevant as they
ensure that we do not incorrectly set the bit.
llvm-svn: 225104
This adds support for IMAGE_REL_ARM_BRANCH24T relocations. Similar to the
IMAGE_REL_ARM_BLX32T relocation, this relocation requires munging an
instruction. The instruction encoding is quite similar, allowing us to reuse
the same munging implementation. This is needed by the entry point stubs for
modules provided by MSVCRT.
llvm-svn: 225082
This adds support for IMAGE_REL_ARM_BLX23T relocations. Similar to the
IMAGE_REL_ARM_MOV32T relocation, this relocation requires munging an
instruction. This inches us closer to supporting a basic hello world
application.
llvm-svn: 225081
This adds support for the IMAGE_REL_ARM_MOV32T relocation. This is one of the
most complicated relocations for the Window on ARM target. It involves
re-encoding an instruction to contain an immediate value which is the relocation
target.
llvm-svn: 225072
This implements the IMAGE_REL_ARM_ADDR32 relocation. There are still a few more
relocation types that need to resolved before lld can even attempt to link a
trivial program for Windows on ARM.
llvm-svn: 225057
This teaches lld about the ARM NT object types. Add a trivial test to ensure
that it can handle ARM NT object file inputs. It is still unable to perform the
necessary relocations for ARM NT, but this allows the linker to at least read
the objects.
llvm-svn: 225052
If you have something like
__declspec(align(8192)) int foo = 1;
in your code, the compiler makes the data to be aligned to 8192-byte
boundary, and the linker align the section containing the data to 8192.
LLD always aligned the section to 4192. So, as long as alignment
requirement is smaller than 4192, it was correct, but for larger
requirements, it's wrong.
This patch fixes the issue.
llvm-svn: 222043
AddressOfEntryPoint is overridden after we layout all atoms (until then,
we don't know the entry point address for obvious reason.)
I believe this code is leftover from very early version of the
PE/COFF port that we only had an entry function in a test object file.
llvm-svn: 222026
SECREL relocation's value is the offset to the beginning of the section.
Because of the off-by-one error, if a SECREL relocation target is at the
beginning of a section, it got wrong value.
Added a test that would have caught this.
llvm-svn: 221420
Many programs, for reasons unknown, really like to look at the
AddressOfRelocationTable to determine whether or not they are looking at
a bona fide PE file. Without this, programs like the UNIX `file'
utility will insist that they are looking at a MS DOS executable.
llvm-svn: 221335
Normally, PE files have section names of eight characters or less.
However, this is problematic for DWARF because DWARF section names are
things like .debug_aranges.
Instead of truncating the section name, redirect the section name into
the string table.
Differential Revision: http://reviews.llvm.org/D6104
llvm-svn: 221212
This is a partial patch to emit the delay-import table. With this,
LLD is now able to emit the table that llvm-readobj can read and
dump.
The table lacks a few fields, such as the address of HMODULE, the
import address table, etc. They'll be added in subsequent patches.
llvm-svn: 219384
In order to support more than x86/x86_64, we need to change the behaviour to use
the actual machine type rather than checking the bitness and assuming that we
are on X86. This replaces the use of is64bit in applyAllRelocations with a
check on the machine type. This will enable adding support for handling ARM
relocations.
Rename the existing applyRelocation methods to be similarly named and to make it
clear the types of relocations they will process.
llvm-svn: 219088
Cache the machine type value of the linking context. We need this in order to
calculate the virtual address of the atom when resolving function symbols.
Windows on ARM must check if the atom is a function and if so, set the Thumb bit
for the returned virtual address. Failure to do so will result in an abnormal
exit due to a trap caused by invalid instruction decoding. The same information
can be used to determine the relocation type that was previously being done via
is64 to select between x86 and x86_64.
llvm-svn: 218106
The contents from section .CRT$XLA to .CRT$XLZ is an array of function
pointers. They are called by the runtime when a new thread is created
or (gracefully) terminated.
You can make your own initialization function to be called by that
mechanism. All you have to do is:
- Define a pointer to a function in a .CRT$XL* section using pragma
- Make an external reference to "__tls_used" symbol
That technique is used in many projects. This patch is to support that.
What this patch does is to set the relative virtual address of
"__tls_used" to the PECOFF directory table. __tls_used is actually a
struct containing pointers to a symbol in .CRT$XLA and another symbol
in .CRT$XLZ. The runtime looks at the directory table, gets the address
of the struct, and call the function pointers between XLA and XLZ.
llvm-svn: 218007
I hope this is the last fix for x64 relocations as I've wasted
a few days on this.
This caused a mysterious issue that some C++ programs crash on
startup. It was because a null pointer is passed as argv to main.
__tmainCRTStartup calls main, but before that it calls all
initialization routines between .text$xc_a and .text$xc_z.
pre_cpp_init is one of such routines, and it is the one who
initializes a heap pointer for argv for later use. That routine
was not called for some reason.
It turned out that __tmainCRTStartup was skipping a block of
code because of the relocation bug. A condition in the function
depends on a memory load, and that memory load was referring
a wrong location. As a result a jump instruction took the
wrong branch, skipping pre_cpp_init and so on.
This patch fixes the issue. Also added more tests to fix them
once and for all.
llvm-svn: 216772
When a relocation is applied to a location, the new value needs
to be added to the existing value at the location. Existing
value is in most cases zero, but if not, the current code does
not work.
llvm-svn: 216680
Image Base field in the PE/COFF header is used as hint for the loader.
If the loader can load the executable at the specified address, that's
fine, but if not, it has to load it at a different address.
If that happens, the loader has to fix up the addresses in the
executable by adding the offset. The list of addresses that need to
be fixed is in .reloc section.
This patch is to emit x64 .reloc section contents.
llvm-svn: 216636
