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* [DebugInfo] Add a DW_OP_LLVM_entry_value operationDavid Stenberg2019-10-151-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Internally in LLVM's metadata we use DW_OP_entry_value operations with the same semantics as DWARF; that is, its operand specifies the number of bytes that the entry value covers. At the time of emitting entry values we don't know the emitted size of the DWARF expression that the entry value will cover. Currently the size is hardcoded to 1 in DIExpression, and other values causes the verifier to fail. As the size is 1, that effectively means that we can only have valid entry values for registers that can be encoded in one byte, which are the registers with DWARF numbers 0 to 31 (as they can be encoded as single-byte DW_OP_reg0..DW_OP_reg31 rather than a multi-byte DW_OP_regx). It is a bit confusing, but it seems like llvm-dwarfdump will print an operation "correctly", even if the byte size is less than that, which may make it seem that we emit correct DWARF for registers with DWARF numbers > 31. If you instead use readelf for such cases, it will interpret the number of specified bytes as a DWARF expression. This seems like a limitation in llvm-dwarfdump. As suggested in D66746, a way forward would be to add an internal variant of DW_OP_entry_value, DW_OP_LLVM_entry_value, whose operand instead specifies the number of operations that the entry value covers, and we then translate that into the byte size at the time of emission. In this patch that internal operation is added. This patch keeps the limitation that a entry value can only be applied to simple register locations, but it will fix the issue with the size operand being incorrect for DWARF numbers > 31. Reviewers: aprantl, vsk, djtodoro, NikolaPrica Reviewed By: aprantl Subscribers: jyknight, fedor.sergeev, hiraditya, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D67492 llvm-svn: 374881
* [DebugInfo] Add interface for pre-calculating the size of emitted DWARFDavid Stenberg2019-10-151-5/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: DWARF's DW_OP_entry_value operation has two operands; the first is a ULEB128 operand that specifies the size of the second operand, which is a DWARF block. This means that we need to be able to pre-calculate and emit the size of DWARF expressions before emitting them. There is currently no interface for doing this in DwarfExpression, so this patch introduces that. When implementing this I initially thought about running through DwarfExpression's emission two times; first with a temporary buffer to emit the expression, in order to being able to calculate the size of that emitted data. However, DwarfExpression is a quite complex state machine, so I decided against that, as it seemed like the two runs could get out of sync, resulting in incorrect size operands. Therefore I have implemented this in a way that we only have to run DwarfExpression once. The idea is to emit DWARF to a temporary buffer, for which it is possible to query the size. The data in the temporary buffer can then be emitted to DwarfExpression's main output. In the case of DIEDwarfExpression, a temporary DIE is used. The values are all allocated using the same BumpPtrAllocator as for all other DIEs, and the values are then transferred to the real value list. In the case of DebugLocDwarfExpression, the temporary buffer is implemented using a BufferByteStreamer which emits to a buffer in the DwarfExpression object. Reviewers: aprantl, vsk, NikolaPrica, djtodoro Reviewed By: aprantl Subscribers: hiraditya, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D67768 llvm-svn: 374879
* [DebugInfo] Fix truncation of call site immediatesDavid Stenberg2019-10-141-1/+1
| | | | | | | | | | | | | | | | | | | | Summary: This addresses a bug in collectCallSiteParameters() where call site immediates would be truncated from int64_t to unsigned. This fixes PR43525. Reviewers: djtodoro, NikolaPrica, aprantl, vsk Reviewed By: aprantl Subscribers: hiraditya, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D68869 llvm-svn: 374770
* DebugInfo: Use base address selection entries for debug_locDavid Blaikie2019-10-111-150/+115
| | | | | | | | Unify the range and loc emission (for both DWARFv4 and DWARFv5 style lists) and take advantage of that unification to use strategic base addresses for loclists. Differential Revision: https://reviews.llvm.org/D68620 llvm-svn: 374600
* Second attempt to add iterator_range::empty()Jordan Rose2019-10-071-2/+2
| | | | | | | | | | | | Doing this makes MSVC complain that `empty(someRange)` could refer to either C++17's std::empty or LLVM's llvm::empty, which previously we avoided via SFINAE because std::empty is defined in terms of an empty member rather than begin and end. So, switch callers over to the new method as it is added. https://reviews.llvm.org/D68439 llvm-svn: 373935
* DebugInfo: Generalize rnglist emission as a precursor to reusing it for ↵David Blaikie2019-10-031-15/+25
| | | | | | loclist emission llvm-svn: 373663
* DebugInfo: Rename DebugLocStream::Entry::Begin/EndSym to just Begin/EndDavid Blaikie2019-10-021-10/+10
| | | | | | | | Brings this struct in line with the RangeSpan class so they might eventually be used by common template code for generating range/loc lists with less duplicate code. llvm-svn: 373540
* DebugInfo: Simplify RangeSpan to be a plain structDavid Blaikie2019-10-021-6/+6
| | | | | | | | | | | | | | This is an effort to make RangeSpan and DebugLocStream::Entry more similar to share code for their emission (to reuse the more complicated code for using (& choosing when to use) base address selection entries, etc). It didn't seem like this struct was worth the complexity of encapsulation - when the members could be initialized by the ctor to any value (no validation) and the type is assignable (so there's no mutability or other constraint being implemented by its interface). llvm-svn: 373533
* DebugInfo: Update support for detecting C++ language variants in debug info ↵David Blaikie2019-10-021-3/+4
| | | | | | emission llvm-svn: 373420
* DebugInfo: Simplify section label caching/usageDavid Blaikie2019-09-301-8/+4
| | | | llvm-svn: 373273
* [Alignment][NFC] Remove unneeded llvm:: scoping on Align typesGuillaume Chatelet2019-09-271-2/+2
| | | | llvm-svn: 373081
* Remove the obsolete BlockByRefStruct flag from LLVM IRAdrian Prantl2019-09-181-47/+1
| | | | | | | | | | | | | | | | | | | | | | | DIFlagBlockByRefStruct is an unused DIFlag that originally was used by clang to express (Objective-)C block captures in debug info. For the last year Clang has been emitting complex DIExpressions to describe block captures instead, which makes all the code supporting this flag redundant. This patch removes the flag and all supporting "dead" code, so we can reuse the bit for something else in the future. Since this only affects debug info generated by Clang with the block extension this mostly affects Apple platforms and I don't have any bitcode compatibility concerns for removing this. The Verifier will reject debug info that uses the bit and thus degrade gracefully when LTO'ing older bitcode with a newer compiler. rdar://problem/44304813 Differential Revision: https://reviews.llvm.org/D67453 llvm-svn: 372272
* [Alignment] Move OffsetToAlignment to Alignment.hGuillaume Chatelet2019-09-121-2/+2
| | | | | | | | | | | | | | | | | Summary: This is patch is part of a series to introduce an Alignment type. See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html See this patch for the introduction of the type: https://reviews.llvm.org/D64790 Reviewers: courbet, JDevlieghere, alexshap, rupprecht, jhenderson Subscribers: sdardis, nemanjai, hiraditya, kbarton, jakehehrlich, jrtc27, MaskRay, atanasyan, jsji, seiya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D67499 llvm-svn: 371742
* [DWARF] Emit call site parameter info when tuning for lldbVedant Kumar2019-09-111-2/+2
| | | | | | | | | Emit debug entry values using standard DWARF5 opcodes when the debugger tuning is set to lldb. Differential Revision: https://reviews.llvm.org/D67410 llvm-svn: 371666
* [DebugInfo][X86] Describe call site values for zero-valued immsDavid Stenberg2019-09-081-12/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Add zero-materializing XORs to X86's describeLoadedValue() hook in order to produce call site values. I have had to change the defs logic in collectCallSiteParameters() a bit to be able to describe the XORs. The XORs implicitly define $eflags, which would cause them to never be considered, due to a guard condition that I->getNumDefs() is one. I have changed that condition so that we now only consider instructions where a forwarded register overlaps with the instruction's single explicit define. We still need to collect the implicit defines of other forwarded registers to remove them from the work list. I'm not sure how to move towards supporting instructions with multiple explicit defines, cases where forwarded register are implicitly defined, and/or cases where an instruction produces values for multiple forwarded registers. Perhaps the describeLoadedValue() hook should take a register argument, and we then leave it up to the hook to describe the loaded value in that register? I have not yet encountered a situation where that would be necessary though. Reviewers: aprantl, vsk, djtodoro, NikolaPrica Reviewed By: vsk Subscribers: ychen, hiraditya, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D67225 llvm-svn: 371333
* [NFC] Make the describeLoadedValue() hook return machine operand objectsDavid Stenberg2019-09-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This changes the ParamLoadedValue pair which the describeLoadedValue() hook returns so that MachineOperand objects are returned instead of pointers. When describing call site values we may need to describe operands which are not part of the instruction. One such example is zero-materializing XORs on x86, which I have implemented support for in a child revision. Instead of having to return a pointer to an operand stored somewhere outside the instruction, start returning objects directly instead, as that simplifies the code. The MachineOperand class only holds POD members, and on x86-64 it is 32 bytes large. That combined with copy elision means that the overhead of returning a machine operand object from the hook does not become very large. I benchmarked this on a 8-thread i7-8650U machine with 32 GB RAM. The benchmark consisted of building a clang 8.0 binary configured with: -DCMAKE_BUILD_TYPE=RelWithDebInfo \ -DLLVM_TARGETS_TO_BUILD=X86 \ -DLLVM_USE_SANITIZER=Address \ -DCMAKE_CXX_FLAGS="-Xclang -femit-debug-entry-values -stdlib=libc++" The average wall clock time increased by 4 seconds, from 62:05 to 62:09, which is an 0.1% increase. Reviewers: aprantl, vsk, djtodoro, NikolaPrica Reviewed By: vsk Subscribers: hiraditya, ychen, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D67261 llvm-svn: 371332
* [DWARF] Rename getDwarf5OrGNUCallSite{Attr,Tag}, NFCVedant Kumar2019-08-261-2/+1
| | | | llvm-svn: 369967
* Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVMDaniel Sanders2019-08-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This clang-tidy check is looking for unsigned integer variables whose initializer starts with an implicit cast from llvm::Register and changes the type of the variable to llvm::Register (dropping the llvm:: where possible). Partial reverts in: X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned& MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register PPCFastISel.cpp - No Register::operator-=() PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned& MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor Manual fixups in: ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned& HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register. PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned& Depends on D65919 Reviewers: arsenm, bogner, craig.topper, RKSimon Reviewed By: arsenm Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D65962 llvm-svn: 369041
* [llvm] Migrate llvm::make_unique to std::make_uniqueJonas Devlieghere2019-08-151-7/+7
| | | | | | | | Now that we've moved to C++14, we no longer need the llvm::make_unique implementation from STLExtras.h. This patch is a mechanical replacement of (hopefully) all the llvm::make_unique instances across the monorepo. llvm-svn: 369013
* [DebugInfo] Consider debug label scope has an extra lexical block fileTaewook Oh2019-08-141-2/+5
| | | | | | | | | | | | | | Summary: There are places where a case that debug label scope has an extra lexical block file is not considered properly. The modified test won't pass without this patch. Reviewers: aprantl, HsiangKai Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66187 llvm-svn: 368891
* Switch LLVM to use 64-bit offsets (2/5)Igor Kudrin2019-08-061-2/+2
| | | | | | | | | This updates all libraries and tools in LLVM Core to use 64-bit offsets which directly or indirectly come to DataExtractor. Differential Revision: https://reviews.llvm.org/D65638 llvm-svn: 368014
* Finish moving TargetRegisterInfo::isVirtualRegister() and friends to ↵Daniel Sanders2019-08-011-1/+2
| | | | | | llvm::Register as started by r367614. NFC llvm-svn: 367633
* Fix unused variable warning for non-assert builds.Eric Christopher2019-07-311-0/+1
| | | | llvm-svn: 367482
* Reland "[DwarfDebug] Dump call site debug info"Djordje Todorovic2019-07-311-15/+197
| | | | | | | | | The build failure found after the rL365467 has been resolved. Differential Revision: https://reviews.llvm.org/D60716 llvm-svn: 367446
* Revert "[DwarfDebug] Dump call site debug info"Djordje Todorovic2019-07-121-172/+15
| | | | | | | | A build failure was found on the SystemZ platform. This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc. llvm-svn: 365886
* [NFC][AsmPrinter] Fix the formatting for the rL365467Djordje Todorovic2019-07-091-8/+6
| | | | | | | In addition, fix the build failure for the 'unused' variable. The variable was used inside the 'LLVM_DEBUG()'. llvm-svn: 365469
* [DwarfDebug] Dump call site debug infoDjordje Todorovic2019-07-091-14/+173
| | | | | | | | | | | | | | | | | | | Dump the DWARF information about call sites and call site parameters into debug info sections. The patch also provides an interface for the interpretation of instructions that could load values of a call site parameters in order to generate DWARF about the call site parameters. ([13/13] Introduce the debug entry values.) Co-authored-by: Ananth Sowda <asowda@cisco.com> Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com> Co-authored-by: Ivan Baev <ibaev@cisco.com> Differential Revision: https://reviews.llvm.org/D60716 llvm-svn: 365467
* [DWARF] Handle the DW_OP_entry_value operandDjordje Todorovic2019-06-271-5/+11
| | | | | | | | | | | | | | | Add the IR and the AsmPrinter parts for handling of the DW_OP_entry_values DWARF operation. ([11/13] Introduce the debug entry values.) Co-authored-by: Ananth Sowda <asowda@cisco.com> Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com> Co-authored-by: Ivan Baev <ibaev@cisco.com> Differential Revision: https://reviews.llvm.org/D60866 llvm-svn: 364542
* [IR] Add DISuprogram and DIE for a func declDjordje Todorovic2019-06-271-0/+5
| | | | | | | | | | | | | | | A unique DISubprogram may be attached to a function declaration used for call site debug info. ([6/13] Introduce the debug entry values.) Co-authored-by: Ananth Sowda <asowda@cisco.com> Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com> Co-authored-by: Ivan Baev <ibaev@cisco.com> Differential Revision: https://reviews.llvm.org/D60713 llvm-svn: 364500
* [DebugInfo] Move Value struct out of DebugLocEntry as DbgValueLoc (NFC)Nikola Prica2019-06-131-11/+11
| | | | | | | | | | | | | Since the DebugLocEntry::Value is used as part of DwarfDebug and DebugLocEntry make it as the separate class. Reviewers: aprantl, dstenb Reviewed By: aprantl Differential Revision: https://reviews.llvm.org/D63213 llvm-svn: 363246
* [DebugInfo] More strict debug range for stack variablesNikola Prica2019-06-101-88/+131
| | | | | | | | | | | | | | | | | | | | | | | | | | | Variable's stack location can stretch longer than it should. If a variable is placed at the stack in a some nested basic block its range can be calculated to be up to the next occurrence of the variable's DBG_VALUE, or up to the end of the function, thus covering a basic blocks that should not be included in the variable’s location range. This happens because the DbgEntityHistoryCalculator ends register locations at the end of a basic block only if the variable’s location register has been changed throughout the function, which is not the case for the register used to reference stack objects. This patch also tries to produce a single value location if the location list builder managed to merge all the locations into one. Reviewers: aprantl, dstenb, jmorse Reviewed By: aprantl, dstenb, jmorse Subscribers: djtodoro, ivanbaev, asowda Tags: #debug-info Differential Revision: https://reviews.llvm.org/D61600 llvm-svn: 362923
* Stop undef fragments from closing non-overlapping fragmentsDavid Stenberg2019-05-281-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: When DwarfDebug::buildLocationList() encountered an undef debug value, it would truncate all open values, regardless if they were overlapping or not. This patch fixes so that it only does that for overlapping fragments. This change unearthed a bug that I had introduced in D57511, which I have fixed in this patch. The code in DebugHandlerBase that changes labels for parameter debug values could break DwarfDebug's assumption that the labels for the entries in the debug value history are monotonically increasing. Before this patch, that bug could result in location list entries whose ending address was lower than the beginning address, and with the changes for undef debug values that this patch introduces it could trigger an assertion, due to attempting to emit location list entries with empty ranges. A reproducer for the bug is added in param-reg-const-mix.mir. Reviewers: aprantl, jmorse, probinson Reviewed By: aprantl Subscribers: javed.absar, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D62379 llvm-svn: 361820
* DWARF v5: emit DW_AT_addr_base if DW_AT_low_pc references .debug_addrFangrui Song2019-05-141-7/+7
| | | | | | | | | | | | | | | | The condition !AddrPool.empty() is tested before attachRangesOrLowHighPC(), which may add an entry to AddrPool. We emit DW_AT_low_pc (DW_FORM_addrx) but may incorrectly omit DW_AT_addr_base for LineTablesOnly. This can be easily reproduced: clang -gdwarf-5 -gmlt -c a.cc Fix this by moving !AddrPool.empty() below. This was discovered while investigating an lld crash (fixed by D61889) on such object files: ld.lld --gdb-index a.o Reviewed By: probinson Differential Revision: https://reviews.llvm.org/D61891 llvm-svn: 360678
* [DebugInfo] Delete TypedDINodeRefFangrui Song2019-05-071-4/+4
| | | | | | | | | | | | | TypedDINodeRef<T> is a redundant wrapper of Metadata * that is actually a T *. Accordingly, change DI{Node,Scope,Type}Ref uses to DI{Node,Scope,Type} * or their const variants. This allows us to delete many resolve() calls that clutter the code. Reviewed By: rnk Differential Revision: https://reviews.llvm.org/D61369 llvm-svn: 360108
* [DebugInfo] DW_OP_deref_size in PrologEpilogInserter.Markus Lavin2019-04-301-0/+4
| | | | | | | | | | | | | | | | | | | | The PrologEpilogInserter need to insert a DW_OP_deref_size before prepending a memory location expression to an already implicit expression to avoid having the existing expression act on the memory address instead of the value behind it. The reason for using DW_OP_deref_size and not plain DW_OP_deref is that big-endian targets need to read the right size as simply truncating a larger read would yield the wrong result (LSB bytes are not at the lower address). This re-commit fixes issues reported in the first one. Namely deref was inserted under wrong conditions and additionally the deref_size argument was incorrectly encoded. Differential Revision: https://reviews.llvm.org/D59687 llvm-svn: 359535
* DebugInfo: Emit only declarations (not whole definitions) of non-unit user ↵David Blaikie2019-04-241-0/+16
| | | | | | | | | | | | | | | | | | | | defined types into type units While this doesn't come up in reasonable cases currently (the only user defined types not in type units are ones without linkage - which makes for near-ODR violations, because it'd be a type with linkage referencing a type without linkage - such a type can't be validly defined in more than one TU, so arguably it shouldn't be in a type unit to begin with - but it's a convenient way to demonstrate an issue that will become more revalent with homed modular debug info type definitions - which also don't need to be in type units but more legitimately so). Precursor to the Clang change to de-type-unit (by omitting the 'identifier') types homed due to strong linkage vtables. (making that change without this one would lead to major type duplication in type units) llvm-svn: 359122
* Reapply: "DebugInfo: Emit only one kind of accelerated access/name table""David Blaikie2019-04-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Originally committed in r358931 Reverted in r358997 Seems this change made Apple accelerator tables miss names (because names started respecting the CU NameTableKind GNU & assuming that shouldn't produce accelerated names too), which is never correct (apple accelerator tables don't have separators or CU lists - if present, they must describe all names in all CUs). Original Description: Currently to opt in to debug_names in DWARFv5, the IR must contain 'nameTableKind: Default' which also enables debug_pubnames. Instead, only allow one of {debug_names, apple_names, debug_pubnames, debug_gnu_pubnames}. nameTableKind: Default gives debug_names in DWARFv5 and greater, debug_pubnames in v4 and earlier - and apple_names when tuning for lldb on MachO. nameTableKind: GNU always gives gnu_pubnames llvm-svn: 359026
* Revert "DebugInfo: Emit only one kind of accelerated access/name table"David Blaikie2019-04-231-3/+0
| | | | | | | | Regresses some apple_names situations - still investigating. This reverts commit r358931. llvm-svn: 358997
* Use llvm::stable_sortFangrui Song2019-04-231-13/+12
| | | | | | While touching the code, simplify if feasible. llvm-svn: 358996
* DebugInfo: Emit only one kind of accelerated access/name tableDavid Blaikie2019-04-221-0/+3
| | | | | | | | | | | | | | | Currently to opt in to debug_names in DWARFv5, the IR must contain 'nameTableKind: Default' which also enables debug_pubnames. Instead, only allow one of {debug_names, apple_names, debug_pubnames, debug_gnu_pubnames}. nameTableKind: Default gives debug_names in DWARFv5 and greater, debug_pubnames in v4 and earlier - and apple_names when tuning for lldb on MachO. nameTableKind: GNU always gives gnu_pubnames llvm-svn: 358931
* [DebugInfo] Improve handling of clobbered fragmentsDavid Stenberg2019-04-101-47/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Currently the DbgValueHistorymap only keeps track of clobbered registers for the last debug value that it has encountered. This could lead to preceding register-described debug values living on longer in the location lists than they should. See PR40283 for an example. This patch does not introduce tracking of multiple registers, but changes the DbgValueHistoryMap structure to allow for that in a follow-up patch. This patch is not NFC, as it at least fixes two bugs in DwarfDebug (both are covered in the new clobbered-fragments.mir test): * If a debug value was clobbered (its End pointer set), the value would still be added to OpenRanges, meaning that the succeeding location list entries could potentially contain stale values. * If a debug value was clobbered, and there were non-overlapping fragments that were still live after the clobbering, DwarfDebug would not create a location list entry starting directly after the clobbering instruction. This meant that the location list could have a gap until the next debug value for the variable was encountered. Before this patch, the history map was represented by <Begin, End> pairs, where a new pair was created for each new debug value. When dealing with partially overlapping register-described debug values, such as in the following example: DBG_VALUE $reg2, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 32, 32) [...] DBG_VALUE $reg3, $noreg, !1, !DIExpression(DW_OP_LLVM_fragment, 64, 32) [...] $reg2 = insn1 [...] $reg3 = insn2 the history map would then contain the entries `[<DV1, insn1>, [<DV2, insn2>]`. This would leave it up to the users of the map to be aware of the relative order of the instructions, which e.g. could make DwarfDebug::buildLocationList() needlessly complex. Instead, this patch makes the history map structure monotonically increasing by dropping the End pointer, and replacing that with explicit clobbering entries in the vector. Each debug value has an "end index", which if set, points to the entry in the vector that ends the debug value. The ending entry can either be an overlapping debug value, or an instruction which clobbers the register that the debug value is described by. The ending entry's instruction can thus either be excluded or included in the debug value's range. If the end index is not set, the debug value that the entry introduces is valid until the end of the function. Changes to test cases: * DebugInfo/X86/pieces-3.ll: The range of the first DBG_VALUE, which describes that the fragment (0, 64) is located in RDI, was incorrectly ended by the clobbering of RAX, which the second (non-overlapping) DBG_VALUE was described by. With this patch we get a second entry that only describes RDI after that clobbering. * DebugInfo/ARM/partial-subreg.ll: This test seems to indiciate a bug in LiveDebugValues that is caused by it not being aware of fragments. I have added some comments in the test case about that. Also, before this patch DwarfDebug would incorrectly include a register-described debug value from a preceding block in a location list entry. Reviewers: aprantl, probinson, dblaikie, rnk, bjope Reviewed By: aprantl Subscribers: javed.absar, kristof.beyls, jdoerfert, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D59941 llvm-svn: 358072
* [DebugInfo] Rename DbgValueHistoryMap::{InstrRange -> Entry}, NFCDavid Stenberg2019-04-101-14/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: In an upcoming commit the history map will be changed so that it contains explicit entries for instructions that clobber preceding debug values, rather than Begin- End range pairs, so generalize the name to "Entry". Also, prefix the iterator variable names in buildLocationList() with "E". In an upcoming commit the entry will have query functions such as "isD(e)b(u)gValue", which could at a glance make one confuse it for iterations over MachineInstrs, so make the iterator names a bit more distinct to avoid that. Reviewers: aprantl Reviewed By: aprantl Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59939 llvm-svn: 358060
* [DebugInfo] Make InstrRange into a class, NFCDavid Stenberg2019-04-101-5/+5
| | | | | | | | | | | | | | | | | | | | Summary: Replace use of std::pair by creating a class for the debug value instruction ranges instead. This is a preparatory refactoring for improving handling of clobbered fragments. In an upcoming commit the Begin pointer will become a PointerIntPair, so it will be cleaner to have a getter for that. Reviewers: aprantl Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59938 llvm-svn: 358059
* [DebugInfo] Pass all values in DebugLocEntry's constructor, NFCDavid Stenberg2019-04-091-18/+5
| | | | | | | | | | | | | | | | | | | | Summary: With MergeValues() removed, amend DebugLocEntry's constructor so that it takes multiple values rather than a single, and keep non-fragment values in OpenRanges, as this allows some cleanup of the code in buildLocationList(). Reviewers: aprantl, dblaikie, loladiro Reviewed By: aprantl Subscribers: hiraditya, llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D59303 llvm-svn: 357988
* [DebugInfo] Remove redundant DebugLocEntry::MergeValues() function, NFCDavid Stenberg2019-04-091-50/+4
| | | | | | | | | | | | | | | | | | | | | | | Summary: The MergeValues() function would try to merge two entries if they shared the same beginning label. Having the same beginning label means that the former entry's range would be empty; however, after D55919 we no longer create entries for empty ranges, so we can no longer land in a situation where that check in MergeValues would succeed. Instead, the "merging" is done by keeping the live values from the preceding empty ranges in OpenRanges, and adding them to the first non-empty range. Reviewers: aprantl, dblaikie, loladiro Reviewed By: aprantl Subscribers: llvm-commits Tags: #debug-info, #llvm Differential Revision: https://reviews.llvm.org/D59301 llvm-svn: 357974
* Revert "[llvm] Reapply "Prevent duplicate files in debug line header in ↵Ali Tamur2019-03-261-1/+0
| | | | | | | | | | | | | dwarf 5."" This reverts commit rL357020. The commit broke the test llvm/test/tools/llvm-objdump/embedded-source.test on some builds including clang-ppc64be-linux-multistage, clang-s390x-linux, clang-with-lto-ubuntu, clang-x64-windows-msvc, llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast (and others). llvm-svn: 357026
* [llvm] Reapply "Prevent duplicate files in debug line header in dwarf 5."Ali Tamur2019-03-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reapply rL356941 after regenerating the object file in the failing test llvm/test/tools/llvm-objdump/embedded-source.test from source. Original commit message: [llvm] Prevent duplicate files in debug line header in dwarf 5. Motivation: In previous dwarf versions, file name indexes started from 1, and the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes the primary source file to be explicitly given an entry with an index number 0. The current implementation honors the specification by just duplicating the main source file, once with index number 0, and later maybe with another index number. While this is compliant with the letter of the standard, the duplication causes problems for consumers of this information such as lldb. (Some files are duplicated, where only some of them have a line table although all refer to the same file) With this change, dwarf 5 debug line section files always start from 0, and the zeroth entry is not duplicated whenever possible. This requires different handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5) However, I think the minor complication is worth it, because it enables all consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the file name list homogenously. Tags: #llvm, #debug-info Differential Revision: https://reviews.llvm.org/D59515 llvm-svn: 357018
* Revert "[llvm] Prevent duplicate files in debug line header in dwarf 5."Ali Tamur2019-03-251-1/+0
| | | | | | | | This reverts commit 312ab05887d0e2caa29aaf843cefe39379a98d36. My commit broke the build; I will revert and find out what happened. llvm-svn: 356951
* [llvm] Prevent duplicate files in debug line header in dwarf 5.Ali Tamur2019-03-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Motivation: In previous dwarf versions, file name indexes started from 1, and the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes the primary source file to be explicitly given an entry with an index number 0. The current implementation honors the specification by just duplicating the main source file, once with index number 0, and later maybe with another index number. While this is compliant with the letter of the standard, the duplication causes problems for consumers of this information such as lldb. (Some files are duplicated, where only some of them have a line table although all refer to the same file) With this change, dwarf 5 debug line section files always start from 0, and the zeroth entry is not duplicated whenever possible. This requires different handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns an index zero for a file name, it signals an error in dwarf 4, but not in dwarf 5) However, I think the minor complication is worth it, because it enables all consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the file name list homogenously. Reviewers: dblaikie, probinson, aprantl, espindola Reviewed By: probinson Subscribers: emaste, jvesely, nhaehnle, aprantl, javed.absar, arichardson, hiraditya, MaskRay, rupprecht, jdoerfert, llvm-commits Tags: #llvm, #debug-info Differential Revision: https://reviews.llvm.org/D59515 llvm-svn: 356941
* [DwarfDebug] Skip entries to big for 16 bit size field in Dwarf < 5.Florian Hahn2019-03-191-1/+7
| | | | | | | | | | | | | | | | Nothing prevents entries from being bigger than the 16 bit size field in Dwarf < 5. For entries that are too big, just emit an empty entry instead of crashing. This fixes PR41038. Reviewers: probinson, aprantl, davide Reviewed By: probinson Differential Revision: https://reviews.llvm.org/D59518 llvm-svn: 356514
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