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* [ARM][MC] Move information about variadic register defs into tablegenOliver Stannard2018-12-031-9/+5
| | | | | | | | | | | | | | | | | | | Currently, variadic operands on an MCInst are assumed to be uses, because they come after the defs. However, this is not always the case, for example the Arm/Thumb LDM instructions write to a variable number of registers. This adds a property of instruction definitions which can be used to mark variadic operands as defs. This only affects MCInst, because MachineInstruction already tracks use/def per operand in each instance of the instruction, so can already represent this. This property can then be checked in MCInstrDesc, allowing us to remove some special cases in ARMAsmParser::isITBlockTerminator. Differential revision: https://reviews.llvm.org/D54853 llvm-svn: 348114
* [ARM][Asm] Debug trace for the processInstruction loopOliver Stannard2018-12-031-3/+9
| | | | | | | | | | | | | | | | | | | In the Arm assembly parser, we first match an instruction, then call processInstruction to possibly change it to a different encoding, to match rules in the architecture manual which can't be expressed by the table-generated matcher. This adds debug printing so that this process is visible when using the -debug option. To support this, I've added a new overload of MCInst::dump_pretty which takes the opcode name as a StringRef, since we don't have an InstPrinter instance in the assembly parser. Instead, we can get the same information directly from the MCInstrInfo. Differential revision: https://reviews.llvm.org/D54852 llvm-svn: 348113
* Revert "[BTF] Add BTF DebugInfo"Yonghong Song2018-11-301-3/+0
| | | | | | This reverts commit 9c6b970db8bc63b28ce58a129bb1580a6a3c6caf. llvm-svn: 348004
* [BTF] Add BTF DebugInfoYonghong Song2018-11-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds BPF Debug Format (BTF) as a standalone LLVM debuginfo. The BTF related sections are directly generated from IR. The BTF debuginfo is generated only when the compilation target is BPF. What is BTF? ============ First, the BPF is a linux kernel virtual machine and widely used for tracing, networking and security. https://www.kernel.org/doc/Documentation/networking/filter.txt https://cilium.readthedocs.io/en/v1.2/bpf/ BTF is the debug info format for BPF, introduced in the below linux patch https://github.com/torvalds/linux/commit/69b693f0aefa0ed521e8bd02260523b5ae446ad7#diff-06fb1c8825f653d7e539058b72c83332 in the patch set mentioned in the below lwn article. https://lwn.net/Articles/752047/ The BTF format is specified in the above github commit. In summary, its layout looks like struct btf_header type subsection (a list of types) string subsection (a list of strings) With such information, the kernel and the user space is able to pretty print a particular bpf map key/value. One possible example below: Withtout BTF: key: [ 0x01, 0x01, 0x00, 0x00 ] With BTF: key: struct t { a : 1; b : 1; c : 0} where struct is defined as struct t { char a; char b; short c; }; How BTF is generated? ===================== Currently, the BTF is generated through pahole. https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=68645f7facc2eb69d0aeb2dd7d2f0cac0feb4d69 and available in pahole v1.12 https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=4a21c5c8db0fcd2a279d067ecfb731596de822d4 Basically, the bpf program needs to be compiled with -g with dwarf sections generated. The pahole is enhanced such that a .BTF section can be generated based on dwarf. This format of the .BTF section matches the format expected by the kernel, so a bpf loader can just take the .BTF section and load it into the kernel. https://github.com/torvalds/linux/commit/8a138aed4a807ceb143882fb23a423d524dcdb35 The .BTF section layout is also specified in this patch: with file include/llvm/BinaryFormat/BTF.h. What use cases this patch tries to address? =========================================== Currently, only the bpf instruction stream is required to pass to the kernel. The kernel verifies it, jits it if configured to do so, attaches it to a particular kernel attachment point, and later executes when a particular event happens. This patch tries to expand BTF to support two more use cases below: (1). BPF supports subroutine calls. During performance analysis, it would be good to differentiate which call is hot instead of just providing a virtual address. This would require to pass a unique identifier for each subroutine to the kernel, the subroutine name is a natual choice. (2). If a particular jitted instruction is hot, we want user to know which source line this jitted instruction belongs to. This would require the source information is available to various profiling tools. Note that in a single ELF file, . there may be multiple loadable bpf programs, . for a particular to-be-loaded bpf instruction stream, its instructions may come from multiple PROGBITS sections, the bpf loader needs to merge them together to a single consecutive insn stream before loading to the kernel. For example: section .text: subroutines funcFoo section _progA: calling funcFoo section _progB: calling funcFoo The bpf loader could construct two loadable bpf instruction streams and load them into the kernel: . _progA funcFoo . _progB funcFoo So per ELF section function offset and instruction offset will need to be adjusted before passing to the kernel, and the kernel essentially expect only one code section regardless of how many in the ELF file. What do we propose and Why? =========================== To support the above two use cases, we propose to add an additional section, .BTF.ext, to the ELF file which is the input of the bpf loader. A different section is preferred since loader may need to manipulate it before loading part of its data to the kernel. The .BTF.ext section has a similar header to the .BTF section and it contains two subsections for func_info and line_info. . the func_info maps the func insn byte offset to a func type in the .BTF type subsection. . the line_info maps the insn byte offset to a line info. . both func_info and line_info subsections are organized by ELF PROGBITS AX sections. pahole is not a good place to implement .BTF.ext as pahole is mostly for structure hole information and more importantly, we want to pass the actual code to the kernel. . bpf program typically is small so storage overhead should be small. . in bpf land, it is totally possible that an application loads the bpf program into the kernel and then that application quits, so holding debug info by the user space application is not practical as you may not even know who loads this bpf program. . having source codes directly kept by kernel would ease deployment since the original source code does not need ship on every hosts and kernel-devel package does not need to be deployed even if kernel headers are used. LLVM is a good place to implement. . The only reliable time to get the source code is during compilation time. This will result in both more accurate information and easier deployment as stated in the above. . Another consideration is for JIT. The project like bcc (https://github.com/iovisor/bcc) use MCJIT to compile a C program into bpf insns and load them to the kernel. The llvm generated BTF sections will be readily available for such cases as well. Design and implementation of emiting .BTF/.BTF.ext sections =========================================================== The BTF debuginfo format is defined. Both .BTF and .BTF.ext sections are generated directly from IR when both "-target bpf" and "-g" are specified. Note that dwarf sections are still generated as dwarf is used by user space tools like llvm-objdump etc. for BPF target. This patch also contains tests to verify generated .BTF and .BTF.ext sections for all supported types, func_info and line_info subsections. The patch is also tested against linux kernel bpf sample tests and selftests. Signed-off-by: Yonghong Song <yhs@fb.com> Differential Revision: https://reviews.llvm.org/D53736 llvm-svn: 347999
* Revert r347490 as it breaks address sanitizer buildsLuke Cheeseman2018-11-233-20/+0
| | | | llvm-svn: 347499
* Revert r343341Luke Cheeseman2018-11-233-0/+20
| | | | | | | - Cannot reproduce the build failure locally and the build logs have been deleted. llvm-svn: 347490
* [MC] Support labels as offsets in .reloc directiveVladimir Stefanovic2018-11-212-20/+55
| | | | | | | | | | | | | | | | | Currently, expressions like .reloc 1f, R_MIPS_JALR, foo 1: nop are not allowed, ie. an offset in .reloc can only be absolute value. This patch adds support for labels as offsets. If offset is a forward declared label, MCObjectStreamer keeps the fixup locally and adds it to the fixups vector after the label (and its offset) is defined. label+number is not supported yet. Differential revision: https://reviews.llvm.org/D53990 llvm-svn: 347397
* [WebAssembly] Remove unused function return types (NFC)Heejin Ahn2018-11-201-6/+4
| | | | | | | | | | Reviewers: sbc100 Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D54734 llvm-svn: 347277
* [WebAssembly] replaced .param/.result by .functypeWouter van Oortmerssen2018-11-192-1/+7
| | | | | | | | | | | | | | | | | | | | | Summary: This makes it easier/cleaner to generate a single signature from this directive. Also: - Adds the symbol name, such that we don't depend on the location of this directive anymore. - Actually constructs the signature in the assembler, and make the assembler own it. - Refactor the use of MVT vs ValType in the streamer and assembler to require less conversions overall. - Changed 700 or so tests to use it. Reviewers: sbc100, dschuff Subscribers: jgravelle-google, eraman, aheejin, sunfish, jfb, llvm-commits Differential Revision: https://reviews.llvm.org/D54652 llvm-svn: 347228
* [WebAssembly] Add support for the event sectionHeejin Ahn2018-11-142-51/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This adds support for the 'event section' specified in the exception handling proposal. (This was named 'exception section' first, but later renamed to 'event section' to take possibilities of other kinds of events into consideration. But currently we only store exception info in this section.) The event section is added between the global section and the export section. This is for ease of validation per request of the V8 team. This patch: - Creates the event symbol type, which is a weak symbol - Makes 'throw' instruction take the event symbol '__cpp_exception' - Adds relocation support for events - Adds WasmObjectWriter / WasmObjectFile (Reader) support - Adds obj2yaml / yaml2obj support - Adds '.eventtype' printing support Reviewers: dschuff, sbc100, aardappel Subscribers: jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D54096 llvm-svn: 346825
* Fix .cfi_restore with register numbers > 64Alexander Richardson2018-11-131-1/+6
| | | | | | | | | | | | | | | | | | | Summary: DW_CFA_restore can only encode register numbers up to 64 (6 bits unsigned int). For regsiter numbers > 64 we have to use DW_CFA_restore_extended instead which uses a ULEB128 value. I discovered this problem in the out-of-tree CHERI target since we use DWARF register number 89 for our return capability register. Reviewers: probinson, dblaikie, aprantl, espindola Reviewed By: dblaikie Subscribers: JohnReagan, emaste, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D54420 llvm-svn: 346751
* [WebAssembly] Added WasmAsmParser.Wouter van Oortmerssen2018-11-123-5/+149
| | | | | | | | | | | | | | | | | | | | | | | Summary: This is to replace the ELFAsmParser that WebAssembly was using, which so far was a stub that didn't do anything, and couldn't work correctly with wasm. This new class is there to implement generic directives related to wasm as a binary format. Wasm target specific directives are still parsed in WebAssemblyAsmParser as before. The two classes now cooperate more correctly too. Also implemented .result which was missing. Any unknown directives will now result in errors. Reviewers: dschuff, sbc100 Subscribers: mgorny, jgravelle-google, eraman, aheejin, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D54360 llvm-svn: 346700
* [DWARFv5] Emit normal type units in .debug_info comdats.Paul Robinson2018-11-091-4/+5
| | | | | | Differential Revision: https://reviews.llvm.org/D54282 llvm-svn: 346540
* [Hexagon] Handle Hexagon's SHF_HEX_GPREL section flagKrzysztof Parzyszek2018-11-092-0/+6
| | | | llvm-svn: 346494
* [ARM64] [Windows] Improve error reporting for unsupported SEH unwind.Eli Friedman2018-11-081-2/+7
| | | | | | | | Use report_fatal_error instead of crashing or miscompiling. (It's currently easier than it should be to hit this case because we don't reuse codes across epilogs.) llvm-svn: 346440
* [WebAssembly] Parsing missing directives to produce valid .oWouter van Oortmerssen2018-11-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Summary: The assembler was able to assemble and then dump back to .s, but was failing to parse certain directives necessary for valid .o output: - .type directives are now recognized to distinguish function symbols and others. - .size is now parsed to provide function size. - .globaltype (introduced in https://reviews.llvm.org/D54012) is now recognized to ensure symbols like __stack_pointer have a proper type set for both .s and .o output. Also added tests for the above. Reviewers: sbc100, dschuff Subscribers: jgravelle-google, aheejin, dexonsmith, kristina, llvm-commits, sunfish Differential Revision: https://reviews.llvm.org/D53842 llvm-svn: 346047
* [WebAssembly] Change indices types to unsined int (NFC)Heejin Ahn2018-11-021-4/+4
| | | | | | | | | | | | | | | | Summary: This changes int types to unsigned int in a few places: function indices and `wasm::Valtype` (which is unsigend int enum). Currently these values cannot have negative values anyway, so this should not be a functional change for now. Reviewers: sbc100 Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D54044 llvm-svn: 346031
* [MC] Implement EmitRawText in MCNullStreamerDaniel Sanders2018-11-011-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This adds dummy implementation of `EmitRawText` in `MCNullStreamer`. This fixes the behavior of `AsmPrinter` with `MCNullStreamer` on targets on which no integrated assembler is used. An attempt to emit inline asm on such a target would previously lead to a crash, since `AsmPrinter` does not check for `hasRawTextSupport` in `EmitInlineAsm` and calls `EmitRawText` anyway if integrated assembler is disabled (the behavior has changed in D2686). Error message printed by MCStreamer: > EmitRawText called on an MCStreamer that doesn't support it, something > must not be fully mc'ized Patch by Eugene Sharygin Reviewers: dsanders, echristo Reviewed By: dsanders Subscribers: eraman, llvm-commits Differential Revision: https://reviews.llvm.org/D53938 llvm-svn: 345841
* [ARM64][Windows] MCLayer support for exception handlingSanjin Sijaric2018-10-273-0/+363
| | | | | | | | | | Add ARM64 unwind codes to MCLayer, as well SEH directives that will be emitted by the frame lowering patch to follow. We only emit unwind codes into object object files for now. Differential Revision: https://reviews.llvm.org/D50166 llvm-svn: 345450
* [Codegen] - Implement basic .debug_loclists section emission (DWARF5).George Rimar2018-10-261-0/+5
| | | | | | | | | .debug_loclists is the DWARF 5 version of the .debug_loc. With that patch, it will be emitted when DWARF 5 is used. Differential revision: https://reviews.llvm.org/D53365 llvm-svn: 345377
* Reland "[WebAssembly] LSDA info generation"Heejin Ahn2018-10-252-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This adds support for LSDA (exception table) generation for wasm EH. Wasm EH mostly follows the structure of Itanium-style exception tables, with one exception: a call site table entry in wasm EH corresponds to not a call site but a landing pad. In wasm EH, the VM is responsible for stack unwinding. After an exception occurs and the stack is unwound, the control flow is transferred to wasm 'catch' instruction by the VM, after which the personality function is called from the compiler-generated code. (Refer to WasmEHPrepare pass for more information on this part.) This patch: - Changes wasm.landingpad.index intrinsic to take a token argument, to make this 1:1 match with a catchpad instruction - Stores landingpad index info and catch type info MachineFunction in before instruction selection - Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an exception table - Adds WasmException class with overridden methods for table generation - Adds support for LSDA section in Wasm object writer Reviewers: dschuff, sbc100, rnk Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D52748 llvm-svn: 345345
* [MC] Separate masm integer literal lexer support from inline asmReid Kleckner2018-10-242-17/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This renames the IsParsingMSInlineAsm member variable of AsmLexer to LexMasmIntegers and moves it up to MCAsmLexer. This is the only behavior controlled by that variable. I added a public setter, so that it can be set from outside or from the llvm-mc command line. We may need to arrange things so that users can get this behavior from clang, but that's future work. I also put additional hex literal lexing functionality under this flag to fix PR32973. It appears that this hex literal parsing wasn't intended to be enabled in non-masm-style blocks. Now, masm integers (0b1101 and 0ABCh) work in __asm blocks from clang, but 0b label references work when using .intel_syntax in standalone .s files. However, 0b label references will *not* work from __asm blocks in clang. They will work from GCC inline asm blocks, which it sounds like is important for Crypto++ as mentioned in PR36144. Essentially, we only lex masm literals for inline asm blobs that use intel syntax. If the .intel_syntax directive is used inside a gnu-style inline asm statement, masm literals will not be lexed, which is compatible with gas and llvm-mc standalone .s assembly. This fixes PR36144 and PR32973. Reviewers: Gerolf, avt77 Subscribers: eraman, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D53535 llvm-svn: 345189
* [DEBUGINFO, NVPTX] Try to pack bytes data into a single string.Alexey Bataev2018-10-242-4/+20
| | | | | | | | | | | | | | | | | | | | Summary: If the target does not support `.asciz` and `.ascii` directives, the strings are represented as bytes and each byte is placed on the new line as a separate byte directive `.b8 <data>`. NVPTX target allows to represent the vector of the data of the same type as a vector, where values are separated using `,` symbol: `.b8 <data1>,<data2>,...`. This allows to reduce the size of the final PTX file. Ptxas tool includes ptx files into the resulting binary object, so reducing the size of the PTX file is important. Reviewers: tra, jlebar, echristo Subscribers: jholewinski, llvm-commits Differential Revision: https://reviews.llvm.org/D45822 llvm-svn: 345142
* [MC] Shrink MCAsmParser by grouping bools, add const, NFCReid Kleckner2018-10-221-1/+1
| | | | | | | | | | | | I was considering adding another boolean here. I standardized on bools since they allow default member initializers in the class definition. This makes ShowParsedOperands protected instead of private, but that's probably fine. Reduce the SmallVector size while we're at it, since the common case is that there is never a pending error. llvm-svn: 344967
* Add missed file from previous commit (r344838)David Blaikie2018-10-201-0/+3
| | | | llvm-svn: 344839
* [MC][DWARF][AsmParser] Ensure nested CFI frames are diagnosed.Kristina Brooks2018-10-192-5/+10
| | | | | | | | | | | | | | | | | | This avoids a crash (with asserts) or bad codegen (without asserts) in Dwarf streamer later on. This patch fixes this condition in MCStreamer and propogates SMLoc down when it's available with an added bonus of source locations for those specific types of errors. Further patches could use similar improvements as currently most non-Windows CFI directives lack an SMLoc parameter. Modified an existing test to verify source location propogation and added an object-file version of it to verify that it does not crash in addition to a standalone test to only ensure it does not crash. Differential Revision: https://reviews.llvm.org/D51695 llvm-svn: 344781
* Revert "[WebAssembly] LSDA info generation"Krasimir Georgiev2018-10-162-9/+1
| | | | | | | | This reverts commit r344575. Newly introduced test eh-lsda.ll.test fails with use-after-free under ASAN build. llvm-svn: 344639
* [mips][micromips] Fix how values in .gcc_except_table are calculatedAleksandar Beserminji2018-10-161-0/+5
| | | | | | | | | | | | | When a landing pad is calculated in a program that is compiled for micromips, it will point to an even address. Such an error will cause a segmentation fault, as the instructions in micromips are aligned on odd addresses. This patch sets the last bit of the offset where a landing pad is, to 1, which will effectively be an odd address and point to the instruction exactly. Differential Revision: https://reviews.llvm.org/D52985 llvm-svn: 344591
* [WebAssembly] LSDA info generationHeejin Ahn2018-10-162-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This adds support for LSDA (exception table) generation for wasm EH. Wasm EH mostly follows the structure of Itanium-style exception tables, with one exception: a call site table entry in wasm EH corresponds to not a call site but a landing pad. In wasm EH, the VM is responsible for stack unwinding. After an exception occurs and the stack is unwound, the control flow is transferred to wasm 'catch' instruction by the VM, after which the personality function is called from the compiler-generated code. (Refer to WasmEHPrepare pass for more information on this part.) This patch: - Changes wasm.landingpad.index intrinsic to take a token argument, to make this 1:1 match with a catchpad instruction - Stores landingpad index info and catch type info MachineFunction in before instruction selection - Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an exception table - Adds WasmException class with overridden methods for table generation - Adds support for LSDA section in Wasm object writer Reviewers: dschuff, sbc100, rnk Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits Differential Revision: https://reviews.llvm.org/D52748 llvm-svn: 344575
* Revert BTF commit series.Eli Friedman2018-10-127-410/+1
| | | | | | | | | | The initial patch was not reviewed, and does not have any tests; it should not have been merged. This reverts 344395, 344390, 344387, 344385, 344381, 344376, and 344366. llvm-svn: 344405
* [BPF] Don't include linux/types.h and fix styleFangrui Song2018-10-123-39/+37
| | | | llvm-svn: 344381
* [BPF] Some fixes after rL344366Fangrui Song2018-10-121-2/+2
| | | | | | | | | | * Move #include outside of namespaces * Add missing #include * Add out-of-line virtual destructor to BTFTypeEntry designated initializers should also be fixed llvm-svn: 344376
* [BPF] Add BTF generation for BPF targetYonghong Song2018-10-127-1/+412
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BTF is the debug format for BPF, a kernel virtual machine and widely used for tracing, networking and security, etc ([1]). Currently only instruction streams are passed to kernel, the kernel verifier verifies them before execution. In order to provide better visibility of bpf programs to user space tools, some debug information, e.g., function names and debug line information are desirable for kernel so tools can get such information with better annotation for jited instructions for performance or other reasons. The dwarf is too complicated in kernel and for BPF. Hence, BTF is designed to be the debug format for BPF ([2]). Right now, pahole supports BTF for types, which are generated based on dwarf sections in the ELF file. In order to annotate performance metrics for jited bpf insns, it is necessary to pass debug line info to the kernel. Furthermore, we want to pass the actual code to the kernel because of the following reasons: . bpf program typically is small so storage overhead should be small. . in bpf land, it is totally possible that an application loads the bpf program into the kernel and then that application quits, so holding debug info by the user space application is not practical. . having source codes directly kept by kernel would ease deployment since the original source code does not need ship on every hosts and kernel-devel package does not need to be deployed even if kernel headers are used. The only reliable time to get the source code is during compilation time. This will result in both more accurate information and easier deployment as stated in the above. Another consideration is for JIT. The project like bcc use MCJIT to compile a C program into bpf insns and load them to the kernel ([3]). The generated BTF sections will be readily available for such cases as well. This patch implemented generation of BTF info in llvm compiler. The BTF related sections will be generated when both -target bpf and -g are specified. Two sections are generated: .BTF contains all the type and string information, and .BTF.ext contains the func_info and line_info. The separation is related to how two sections are used differently in bpf loader, e.g., linux libbpf ([4]). The .BTF section can be loaded into the kernel directly while .BTF.ext needs loader manipulation before loading to the kernel. The format of the each section is roughly defined in llvm:include/llvm/MC/MCBTFContext.h and from the implementation in llvm:lib/MC/MCBTFContext.cpp. A later example also shows the contents in each section. The type and func_info are gathered during CodeGen/AsmPrinter by traversing dwarf debug_info. The line_info is gathered in MCObjectStreamer before writing to the object file. After all the information is gathered, the two sections are emitted in MCObjectStreamer::finishImpl. With cmake CMAKE_BUILD_TYPE=Debug, the compiler can dump out all the tables except insn offset, which will be resolved later as relocation records. The debug type "btf" is used for BTFContext dump. Dwarf tests the debug info generation with llvm-dwarfdump to decode the binary sections and check whether the result is expected. Currently we do not have such a tool yet. We will implement btf dump functionality in bpftool ([5]) as the bpftool is considered the recommended tool for bpf introspection. The implementation for type and func_info is tested with linux kernel test cases. The line_info is visually checked with dump from linux kernel libbpf ([4]) and checked with readelf dumping section raw data. Note that the .BTF and .BTF.ext information will not be emitted to assembly code and there is no assembler support for BTF either. In the below, with a clang/llvm built with CMAKE_BUILD_TYPE=Debug, Each table contents are shown for a simple C program. -bash-4.2$ cat -n test.c 1 struct A { 2 int a; 3 char b; 4 }; 5 6 int test(struct A *t) { 7 return t->a; 8 } -bash-4.2$ clang -O2 -target bpf -g -mllvm -debug-only=btf -c test.c Type Table: [1] FUNC name_off=1 info=0x0c000001 size/type=2 param_type=3 [2] INT name_off=12 info=0x01000000 size/type=4 desc=0x01000020 [3] PTR name_off=0 info=0x02000000 size/type=4 [4] STRUCT name_off=16 info=0x04000002 size/type=8 name_off=18 type=2 bit_offset=0 name_off=20 type=5 bit_offset=32 [5] INT name_off=22 info=0x01000000 size/type=1 desc=0x02000008 String Table: 0 : 1 : test 6 : .text 12 : int 16 : A 18 : a 20 : b 22 : char 27 : test.c 34 : int test(struct A *t) { 58 : return t->a; FuncInfo Table: sec_name_off=6 insn_offset=<Omitted> type_id=1 LineInfo Table: sec_name_off=6 insn_offset=<Omitted> file_name_off=27 line_off=34 line_num=6 column_num=0 insn_offset=<Omitted> file_name_off=27 line_off=58 line_num=7 column_num=3 -bash-4.2$ readelf -S test.o ...... [12] .BTF PROGBITS 0000000000000000 0000028d 00000000000000c1 0000000000000000 0 0 1 [13] .BTF.ext PROGBITS 0000000000000000 0000034e 0000000000000050 0000000000000000 0 0 1 [14] .rel.BTF.ext REL 0000000000000000 00000648 0000000000000030 0000000000000010 16 13 8 ...... -bash-4.2$ The latest linux kernel ([6]) can already support .BTF with type information. The [7] has the reference implementation in linux kernel side to support .BTF.ext func_info. The .BTF.ext line_info support is not implemented yet. If you have difficulty accessing [6], you can manually do the following to access the code: git clone https://github.com/yonghong-song/bpf-next-linux.git cd bpf-next-linux git checkout btf The change will push to linux kernel soon once this patch is landed. References: [1]. https://www.kernel.org/doc/Documentation/networking/filter.txt [2]. https://lwn.net/Articles/750695/ [3]. https://github.com/iovisor/bcc [4]. https://github.com/torvalds/linux/tree/master/tools/lib/bpf [5]. https://github.com/torvalds/linux/tree/master/tools/bpf/bpftool [6]. https://github.com/torvalds/linux [7]. https://github.com/yonghong-song/bpf-next-linux/tree/btf Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Differential Revision: https://reviews.llvm.org/D52950 llvm-svn: 344366
* [mips] Fix FDE/CFI encoding in case of N32 ABISimon Atanasyan2018-10-091-3/+3
| | | | | | | | | | For O32 and N32 ABI FDE/CFI encoding should be `DW_EH_PE_sdata4` and only N64 ABI uses `DW_EH_PE_sdata8`. To cover all cases this patch check code pointer size and setup a correct FDE/CFI encoding type. Differential revision: https://reviews.llvm.org/D52876 llvm-svn: 344040
* [AsmParser] Return an error in the case of empty symbol ref in an expressionFrancis Visoiu Mistrih2018-10-081-1/+1
| | | | | | | | | | | | | | The following instruction: > str q28, [x0, #1*6*4*@] contains a @ which is parsed as an empty symbol. The parser returns true but has no error, so the assembler continues by ignoring the instruction. Differential Revision: https://reviews.llvm.org/D52645 llvm-svn: 343961
* [WebAssembly] Fixed missing "global" symbol type in AsmParser.Wouter van Oortmerssen2018-10-041-0/+1
| | | | | | | | | | | | | | | Summary: These are emitted by the wasm backend for e.g. __stack_pointer@GLOBAL which previously wasn't accepted by the assembler. Reviewers: aheejin, dschuff Subscribers: sbc100, jgravelle-google, llvm-commits, sunfish Differential Revision: https://reviews.llvm.org/D52911 llvm-svn: 343830
* [WebAssembly] Refactor WasmSignature and use it for MCSymbolWasmDerek Schuff2018-10-031-2/+5
| | | | | | | | | | | | MCContext does not destroy MCSymbols on shutdown. So, rather than putting SmallVectors (which may heap-allocate) inside MCSymbolWasm, use unowned pointer to a WasmSignature instead. The signatures are now owned by the AsmPrinter. Also uses WasmSignature instead of param and result vectors in TargetStreamer, and leaves some TODOs for further simplification. Differential Revision: https://reviews.llvm.org/D52580 llvm-svn: 343733
* Revert r343317Luke Cheeseman2018-09-283-20/+0
| | | | | | - asan buildbots are breaking and I need to investigate the issue llvm-svn: 343341
* Reapply changes reverted by r343235Luke Cheeseman2018-09-283-0/+20
| | | | | | | | - Add fix so that all code paths that create DWARFContext with an ObjectFile initialise the target architecture in the context - Add an assert that the Arch is known in the Dwarf CallFrameString method llvm-svn: 343317
* Revert r343192 as an ubsan build is currently failingLuke Cheeseman2018-09-273-20/+0
| | | | llvm-svn: 343235
* Reapply changes reverted in r343114, lldb patch to follow shortlyLuke Cheeseman2018-09-273-0/+20
| | | | llvm-svn: 343192
* llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)Fangrui Song2018-09-272-6/+5
| | | | | | | | | | | | Summary: The convenience wrapper in STLExtras is available since rL342102. Reviewers: dblaikie, javed.absar, JDevlieghere, andreadb Subscribers: MatzeB, sanjoy, arsenm, dschuff, mehdi_amini, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, javed.absar, gbedwell, jrtc27, mgrang, atanasyan, steven_wu, george.burgess.iv, dexonsmith, kristina, jsji, llvm-commits Differential Revision: https://reviews.llvm.org/D52573 llvm-svn: 343163
* Revert r343112 as CallFrameString API change has broken lldb buildsLuke Cheeseman2018-09-263-20/+0
| | | | llvm-svn: 343114
* [AArch64] - Return address signing dwarf supportLuke Cheeseman2018-09-263-0/+20
| | | | | | - Reapply r343089 with a fix for DebugInfo/Sparc/gnu-window-save.ll llvm-svn: 343112
* Revert r343089 "[AArch64] - Return address signing dwarf support"Hans Wennborg2018-09-263-20/+0
| | | | | | | | | | | | | | | | | | | This caused the DebugInfo/Sparc/gnu-window-save.ll test to fail. > Functions that have signed return addresses need additional dwarf support: > - After signing the LR, and before authenticating it, the LR register is in a > state the is unusable by a debugger or unwinder > - To account for this a new directive, .cfi_negate_ra_state, is added > - This directive says the signed state of the LR register has now changed, > i.e. unsigned -> signed or signed -> unsigned > - This directive has the same CFA code as the SPARC directive GNU_window_save > (0x2d), adding a macro to account for multiply defined codes > - This patch matches the gcc implementation of this support: > https://patchwork.ozlabs.org/patch/800271/ > > Differential Revision: https://reviews.llvm.org/D50136 llvm-svn: 343103
* [AArch64] - Return address signing dwarf supportLuke Cheeseman2018-09-263-0/+20
| | | | | | | | | | | | | | | | | Functions that have signed return addresses need additional dwarf support: - After signing the LR, and before authenticating it, the LR register is in a state the is unusable by a debugger or unwinder - To account for this a new directive, .cfi_negate_ra_state, is added - This directive says the signed state of the LR register has now changed, i.e. unsigned -> signed or signed -> unsigned - This directive has the same CFA code as the SPARC directive GNU_window_save (0x2d), adding a macro to account for multiply defined codes - This patch matches the gcc implementation of this support: https://patchwork.ozlabs.org/patch/800271/ Differential Revision: https://reviews.llvm.org/D50136 llvm-svn: 343089
* [MCAsmParser] Move AltMacroMode tracking out of MCAsmLexerCraig Topper2018-09-252-10/+9
| | | | | | | | The Lexer doesn't use this state itself. It is only set and used by AsmParser so it seems like it should just be part of AsmParser. Differential Revision: https://reviews.llvm.org/D52515 llvm-svn: 343027
* [MC] Return a std::string instead of taking it as an out parameter. Make two ↵Craig Topper2018-09-251-7/+5
| | | | | | parser methods into static functions at file scope. NFC llvm-svn: 343020
* [MC] Fix bad indentation and 80 column violations. Use StringRef::front ↵Craig Topper2018-09-251-29/+34
| | | | | | instead of dereferencing StringRef::begin. NFC llvm-svn: 343010
* [MC] Replace NULL constant in code with nullptr.Craig Topper2018-09-251-1/+1
| | | | llvm-svn: 343003
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