This patch updates MachOLinkGraphBuilder to honor the MH_SUBSECTIONS_VIA_SYMBOLS
flag. Prior to this patch we assumed MH_SUBSECTIONS_VIA_SYMBOLS, but never
checked the flag.
If MH_SUBSECTIONS_VIA_SYMBOLS is set (the default for MachO output on modern
compilers) then MachOLinkGraphBuilder will break MachO section content into
jitlink::Blocks on symbol boundaries. (This is how JITLink has always handled
MachO sections previously).
If MH_SUBSECTIONS_VIA_SYMBOLS is not set then MachOLinkGraphBuilder will create
a single jitlink::Block for each MachO section.
Existing hand-written testcases that were _not_ using the
.subsections_via_symbols directive are updated to use it. A new testcase for
non-subsections-via-symbols behavior is included.
I (lhames) accidentally pushed 5f300397c6 on
Kshitij Jain's behalf without updating the patch author first (my apologies
Kshitij!).
Re-applying with correct authorship.
https://reviews.llvm.org/D131347
Implements SECTION/SECREL relocation. These are used by debug info (pdb) data.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130275
Handles COMDAT symbol with an offset and refactor the code to only generated symbol if the second symbol was encountered. This happens very infrequently but happens in recursive_mutex implementation of MSVC STL library.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130454
Implements remaining IMAGE_REL_AMD64_REL32_*. We only need IMAGE_REL_AMD64_REL32_4 for now but doing all remaining ones for completeness. (clang only uses IMAGE_REL_AMD64_REL32_1 and IMAGE_REL_AMD64_REL32)
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130452
Implements include/alternatename linker directive. Alternatename is used by static msvc runtime library. Alias symbol is technically incorrect (we have to search for external definition) but we don't have a way to represent this in jitlink/orc yet, this is solved in the following up patch.
Inlcude linker directive is used in ucrt to forcelly lookup the static initializer symbols so that they will be emitted. It's implemented as extenral symbols with live flag on that cause the lookup of these symbols.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130276
Implements include/alternatename linker directive. Alternatename is used by static msvc runtime library. Alias symbol is technically incorrect (we have to search for external definition) but we don't have a way to represent this in jitlink/orc yet, this is solved in the following up patch.
Inlcude linker directive is used in ucrt to forcelly lookup the static initializer symbols so that they will be emitted. It's implemented as extenral symbols with live flag on that cause the lookup of these symbols.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130276
Implements dllimport stubs using GOT table manager. Benefit of using GOT table manager is that we can just reuse jitlink-check architecture.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130175
Adds keep-alive edges to pdata section to prevent dead strip of block when its parent function is alive.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129945
Implement IMAGE_COMDAT_SELECT_LARGEST partially. It's going to fail if larger symbol appears but this hasn't happened at least in vcruntime library.
We probably would not implement this properly as it requires complicated runtime patching which is not of nature of JIT. However, we'd like to validate if larger section appears and report to the user in the near future.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129941
Implement IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY/LIBRARY characteristics flag.
Since COFFObjectFile class will set undefined flag for symbols with no alias flag, ORC ObjectFileInterface will not pull in this symbol. So, we only need to make sure the scope is local. NOLIBRARY and LIBRARY are handled in the same way for now. (which is what lld does right now)
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129939
Handles duplicate external symbols. This happens in few static libraries generaed from msvc toolchain.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129937
Reimplements ADDR32NB/REL32 relocations properly, out-of-reach targets will be dealt in the separate patch that will generate the stub for dllimport symbols.
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D129936
Properly set weak flag to COMDAT symbols so that no duplicate definition error will be generated. There is an inaccuracy in setting plain weak for largest selection type, which will be dealt with soon when largest type is properly implemented.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129764
AcceptedPublic
Implements IMAGE_SYM_CLASS_LABEL. It's simply a section + offset. This is not used a lot by llvm mc but very commonly used by MSVC compiler.
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D129754
Handle out-of-order COMDAT second symbols. In llvm codegen, the second symbol of COMDAT sequence always follows the first symbol in the global symbol list. But, when the object file came from MSVC compiler, these can come in out of order.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D129721
This prevents the dead strip of associative comdat section when parent section is alive.
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D129720
Adds initial COFF support in JITLink. This is able to run a hello world c program in x86 windows successfully.
Implemented
- COFF object loader
- Static local symbols
- Absolute symbols
- External symbols
- Weak external symbols
- Common symbols
- COFF jitlink-check support
- All COMDAT selection type execpt largest
- Implicit symobl size calculation
- Rel32 relocation with PLT stub.
- IMAGE_REL_AMD64_ADDR32NB relocation
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D128968
Define atexit symbol in GenericLLVMIRPlatformSupport so that it doesn't need to be defined by user.
On windows, llvm codegen emits atexit runtime calls to support global deinitializers as there is no lower function like cxa_atexit as in Itanium C++ ABI. ORC JIT user had to define custom atexit symbol manually. This was a hassle as it has to deal with dso_handle and cxa_atexit internals of LLJIT. If client didn't provide atexit definition, the default behaviour is just linking with host atexit function which is destined to fail as it calls dtors when the host program exits. This is after jit instances and buffers are freed, so users would see weird access violation exception from the uknown location. (in console application, the debugger thinks exception happened in scrt_common_main_seh)
This is a hack that has some caveats. (e.g. memory address is not identical) But, it's better than the situation described in the above. Ultimately, we will move on to ORC runtime that is able to solve the memory address issue properly.
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D128037
Implements R_AARCH64_MOVW_UABS_G*_NC fixup edges. These relocation entries can be generated when code is compiled without a PIC flag. With this patch, clang-repl can printf Hello World with ObjectLinkerLayer on aarch64 linux.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D127585
Implements eh frame handling by using generic EHFrame passes. The c++ exception handling works correctly with this change.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D127063
Implements Procedure Linkage Table (PLT) for ELF/AARCH64. The aarch64 linux calling convention also uses r16 as the intra-procedure-call scratch register same as MachO/ARM64. We can use the same stub sequence for this reason.
Also, BR regiseter doesn't touch X30 register. External function call by BL instruction (touched by CALL26 relocation) will set X30 to the original PC + 4, which is the intended behavior. External function call by B instruction (touched by JUMP26 relocation) doesn't requite to set X30, so the patch will be correct in this case too.
Reference: https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#611general-purpose-registers
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D127061
Implements R_AARCH64_JUMP26. We can use the same generic aarch64 Branch26 edge since B instruction and BL nstruction have the same sized&offseted immediate field, and the relocation address calculation is the same.
Reference: ELF for the ARM ® 64-bit Architecture Tabel 4-10, ARM Architecture Reference Manual ® ARMv8, for ARMv8-A architecture profile C6.2.24, C6.2.31
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D127059
This patch implements R_AARCH64_PREL64 and R_AARCH64_PREL32 relocations that is
used in eh frame pointers. The test case utlizes obj2yaml tool to create an
artifical eh frame that generates related relocation types.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D127058
This patch implements two most commonly used Global Offset Table relocations in
ELF/AARCH64: R_AARCH64_ADR_GOT_PAGE and R_AARCH64_LD64_GOT_LO12_NC. It
implements the GOT table manager by extending the existing
PerGraphGOTAndPLTStubsBuilder. A future patch will unify this with the MachO
implementation to produce a generic aarch64 got table manager.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D127057
Implement R_AARCH64_ABS64 relocation entry. This relocation type is generated
when creating a static function pointer to symbol.
Reviewed By: lhames, sgraenitz
Differential Revision: https://reviews.llvm.org/D126658
Implement R_AARCH64_LDST*_ABS_LO12_NC relocaiton entries by reusing PageOffset21
generic relocation edge. The difference between MachO backend is that in ELF,
the shift value is explicitly given by relocation type. lld generates the
relocation type that matches with instruction bitwidth, so getting the shift
value implicitly from instruction bytes should be fine in typical use cases.
Make old JIT ExecutionEngine tests unsupported for RISCV, like many other architectures included.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D126188
On some platforms _ZTIi may not be present (see discussion at
https://reviews.llvm.org/rG43acef48d38e). We don't need this symbol for the
test to work, so just add -phony-externals to the testcase to suppress the
error.
Adds support for pointer encodings commonly used in large/static models,
including non-pcrel, sdata/udata8, indirect, and omit.
Also refactors pointer-encoding handling to consolidate error generation inside
common functions, rather than callees of those functions.
Removes a bogus dyn_cast_or_null that was breaking cast-expression handling when
parsing llvm.global_ctors.
The intent of this code was to identify Functions nested within cast
expressions, but the offending dyn_cast_or_null was actually blocking that:
Since a function is not a cast expression, we would set FuncC to null and break
the loop without finding the Function. The cast was not necessary either:
Functions are already Constants, and we didn't need to do anything
ConstantExpr-specific with FuncC, so we could just drop the cast.
Thanks to Jonas Hahnfeld for tracking this down.
http://llvm.org/PR54797
This function had been assuming a 1-byte alignment, which isn't always correct.
This commit updates it to take the alignment from the __cstring section.
The key change is to the createContentBlock call, but the surrounding code is
updated with clearer debugging output to support the testcase (and any future
debugging work).
The sort should have been lexicographic, but wasn't. This resulted in us
choosing a common symbol at address zero over the intended target function,
leading to a crash.
This patch also moves sorting up to the start of the pass, which means that we
only need to hold on to the canonical symbol at each address rather than a list
of candidates.
EHFrameSplitter does the exact same work to split up the eh_frame as it would need for any section that follows the DWARF record, therefore this patch just changes the name of it to DWARFRecordSectionSplitter to be more general.
Differential Revision: https://reviews.llvm.org/D121486
When an external symbol is converted to an absolute it should be demoted to
local scope so that the symbol does not become a new definition within this
LinkGraph.
This patch removes the unintended resolution of locally scoped absolute symbols
(which was causing unexpected definition errors).
It stops using the JITSymbolFlags::Absolute flag (it isn't set or used elsewhere,
and causes mismatch-flags asserts), and adds JITSymbolFlags::Exported to default
scoped absolute symbols.
Finally, we now set the scope of absolute symbols correctly in
MachOLinkGraphBuilder.
This patch supports the R_RISCV_JAL relocation.
Moreover, it will fix the extractBits function's behavior as it extracts Size + 1 bits.
In the test ELF_jal.s:
Before:
```
Hi: 4294836480
extractBits(Hi, 12, 8): 480
```
After:
```
Hi: 4294836480
extractBits(Hi, 12, 8): 224
```
Reviewed By: StephenFan
Differential Revision: https://reviews.llvm.org/D117975
sunho
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