This patch adds support for R_X86_64_PC16 relocation type and
x86_64::Delta16 edge kind. This patch also adds missing test cases for
R_X86_64_PC32, R_X86_64_PC64 relocation types.
LinkGraph::splitBlock used to take a single split-point to split a Block into
two. In the common case where a block needs to be split repeatedly (e.g. in
eh-frame and compact-unwind sections), iterative calls to splitBlock could
lead to poor performance as symbols and edges are repeatedly shuffled to new
blocks.
This commit updates LinkGraph::splitBlock to take a sequence of split offsets,
allowing a block to be split into an arbitrary number of new blocks. Internally,
Symbols and Edges only need to be moved once (directly to whichever new block
they will be associated with), leading to better performance.
On some large MachO object files in an out of tree project this change improved
the performance of splitBlock by several orders of magnitude.
rdar://135820493
This allows us to rewrite part of StaticLibraryDefinitionGenerator in terms of
loadLinkableFile.
It's also useful for clients who may not know (either from file extensions or
context) whether a given path will be an object file, an archive, or a
universal binary.
rdar://134638070
This relocation is used in order to address GOT entries using 15 bit
offset in ldr instruction. The offset is calculated relative to GOT
section page address.
This reapplies 785d376d123, which was reverted in c49837f5f68 due to bot
failures. The fix was to relax some asserts to allow common symbols to be
resolved with either common or weak flags, rather than requiring one or the
other.
Duplicate common definitions should be coaleseced, rather than being treated as
duplicate definitions. Strong definitions should override common definitions.
rdar://132314264
The ARM architecture uses the LSB bit for ARM/Thumb mode switch
flagging. This is true for alignments of 2 and 4 but in data
relocations the alignment is 1 allowing the LSB bit to be set.
Now only `ELF::STT_FUNC` typed symbols are used in the
TargetFlag mechanism.
The test is a minimal example of the issue mentioned below.
Fixes#95911 "Orc global constructor order test fails on 32
bit ARM".
`TargetEndianness` is long and unwieldy. "Target" in the name is confusing. Rename it to "Endianness".
I cannot find noticeable out-of-tree users of `TargetEndianness`, but
keep `TargetEndianness` to make this patch safer. `TargetEndianness`
will be removed by a subsequent change.
Transform section$start$<section-name> and section$end$<section-name> external
symbols into defined symbols when a section named <section-name> is present.
rdar://125357048
Coding my way home: 8.98112N, 79.52094W
This commit adds section start and stop symbol handling to ELF/aarch64, and
fixes the section symbol prefixes (using `__start_` and `__stop_`, rather than
`__start` and `__end`). It also adds a testcase for handling of these symbols.
Right now InProcessMemoryManager only releases a standard segment (via
sys::Memory::releaseMappedMemory) in `deallocate` when there is a
DeallocAction associated, leaving residual memory pages in the process
until termination.
Despite being a de facto memory leak, it won't cause a major issue if
users only create a single LLJIT instance per process, which is the most
common use cases. It will, however, drain virtual memory pages if we
create thousands of ephemeral LLJIT instances in the same process.
This patch fixes this issue by releasing every standard segments
regardless of the attached DeallocAction.
As noted in issues #68594 and #73935, `JITLink/RISCV/ELF_ehframe.s`
fails with libstdc++'s expensive checks because `getRISCVPCRelHi20`
calls `std::equal_range` on the edges which may not be ordered by their
offset. Instead let `ELFJITLinker_riscv` build a hashmap of all edges
with type `R_RISCV_PCREL_HI20` that can be looked up in constant time.
Closes#73935
The error check should be performed after the iterator increment, not before
it. Thanks to @dcb314 for catching this!
Fixes github.com/apple/swift/issues/81119
This code appears to be a hack to set the features to include compressed
instructions if the ELF EFLAGS flags bit is present, but the ELF
attribute for the ISA string is no present or not accurate.
We can't remove the hack because llvm-mc doesn't create ELF attributes
by default so a lot of tests fail to disassembler properly. Using clang
as the assembler does set the attributes.
This patch changes the hack to only set Zca since that is the minimum
implied by the flag. Setting anything else potentially conflicts with
the ISA string containing Zcmp or Zcmt.
JITLink also needs to be updated to recognize Zca in addition to C.
This stub type loads an absolute address directly into the PC register.
It's the simplest and most compatible way to implement a branch
indirection across the entire address space (and probably the slowest as
well). It's the ideal fallback for all targets for which we did not
(yet) implement a more performant solution.
`R_ARM_PREL31` is a 31-bits relative data relocation where the
most-significant bit is preserved. It's used primarily in `.ARM.exidx`
sections, which we skipped processing until now, because we didn't
support the relocation type. This was implemented in RuntimeDyld with
https://reviews.llvm.org/D25069 and I implemented it in a similar way in
JITLink in order to reach feature parity.
We want to emit stubs that match the instruction set state of the
relocation site. This is important for branches that have no built-in
switch for the instruction set state. It's the case for Jump24
relocations. Relocations on instructions that support switching on
the fly will be rewritten in a relaxation step in the future. This
affects Call relocations on `BL`/`BLX` instructions.
In this patch, the StubManager gains a second stub symbol slot for each
target and selects which one to use based on the relocation type. For
testing, we select the appropriate slot with a stub-kind filter, i.e.
`arm` or `thumb`. With that we can implement Armv7 stubs and test
that we can have both kinds of stubs for a single external symbol.
Adds a function to create a LinkGraph of absolute symbols, and a
callback in dynamic library search generators to enable using it to
expose its symbols to the platform/orc runtime. This allows e.g. using
__orc_rt_run_program to run a precompiled function that was found via
dlsym. Ideally we would use this in llvm-jitlink's own search generator,
but it will require more work to align with the Process/Platform
JITDylib split, so not handled here.
As part of this change we need to handle LinkGraphs that only have
absolute symbols.
Previously the JITLink MachO backends (aarch64 and x86-64) only looked at the
fixup block to determine which symbol was being fixed up. This assumption breaks
if both symbols used in the subtractor are in the same block. The fix is to
check for such cases and use the offsets of each symbol to decide which is being
fixed up.
The issue only resulted in incorrect behavior for negative-delta relocations,
so the testcases use eh-frames with explicit edges for the CIE-pointer field in
FDEs (since these are negative-deltas).
rdar://119351329
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
Specifying relocation fixup constants with name and type facilitates
readability and compile-time checks. The `FixupInfo<EdgeKind>` facade
organizes the information into entries per relocation type and provides
uniform access across Arm and Thumb relocations. Since it uses template
specializations, it doesn't limit potential entries. We cannot access
the entries dynamically though, because `EdgeKind` must be given as a
compile-time constant.
With this patch we populate a static lookup table on-demand and use it
for dynamic access in opcode-checks.
Reading implicit addend from a relocation site doesn't require a complete
`LinkGraph` edge. The operation is independent from `TargetSymbol`,
but constructing an `Edge` instance required one. This patch fixes the
inconsistency and simplifies some setup code from the error unittests.
Furthermore this patch prepares for the `Arm`/`Thumb`/`Data` helper
functions to be turned into implementation details. Exposing them in the
API causes unfortunate inconsistencies that we don't want to error-check
all the time, e.g. passing `Thumb_Call` to `readAddendArm()`.
Support for ELF::R_ARM_THM_MOVW_PREL_NC and ELF::R_ARM_THM_MOVT_PREL
is added. Move instructions with PC-relative immediates can be handled
in Thumb mode with this addition.
The pass only requires that it can determine a uniquely identified
target at some offsets. Multiple relocations at the same offset are fine
otherwise and will be required when adding exception handling support
for RISC-V.
These files satisfy all of the following:
- misc-include-cleaner indicates that these files do not need
Endian.h.
- They do not mention "endian" anywhere.
- They do not include any *.inc or *.def, which could need
llvm::support::endian.
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class. This patch replaces
{big,little,native} with llvm::endianness::{big,little,native}.
This patch completes the migration to llvm::endianness and
llvm::endianness::{big,little,native}. I'll post a separate patch to
remove the migration helpers in llvm/Support/Endian.h:
using endianness = llvm::endianness;
constexpr llvm::endianness big = llvm::endianness::big;
constexpr llvm::endianness little = llvm::endianness::little;
constexpr llvm::endianness native = llvm::endianness::native;
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
Now that llvm::support::endianness has been renamed to
llvm::endianness, we can use the shorter form. This patch replaces
support::endianness with llvm::endianness.
Now that llvm::support::endianness has been renamed to
llvm::endianness, we can use the shorter form. This patch replaces
support::endianness::{big,little,native} with
llvm::endianness::{big,little,native}.
This restores the pre-b9383a86b8f behavior. Most platforms / compilers don't
add relocations for CIEs, however they're not prohibited and we want objects
that contain them to remain loadable.
* Remove unused variable.
* Error on existing edge at CIE pointer field.
* Simplify CFI processing in `EHFrameEdgeFixer`: The code expects
`DWARFRecordSectionSplitter` to split each CFI record into its own
block, so remove loop over possibly multiple entries in one block.
