DWARF files may contain overlapping address ranges. f.e. it can happen if the two
copies of the function have identical instruction sequences and they end up sharing.
That looks incorrect from the point of view of DWARF spec. Current implementation
of DWARFLinker does not combine overlapped address ranges. It would be good if such
ranges would be handled in some useful way. Thus, this patch allows DWARFLinker
to combine overlapped ranges in a single one.
Depends on D86539
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D123469
DWARF files may contain overlapping address ranges. f.e. it can happen if the two
copies of the function have identical instruction sequences and they end up sharing.
That looks incorrect from the point of view of DWARF spec. Current implementation
of DWARFLinker does not combine overlapped address ranges. It would be good if such
ranges would be handled in some useful way. Thus, this patch allows DWARFLinker
to combine overlapped ranges in a single one.
Depends on D86539
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D123469
This patch implements proposal https://lists.llvm.org/pipermail/llvm-dev/2020-August/144579.html
llvm-dwarfutil - is a tool that is used for processing debug info(DWARF) located in built binary files to improve debug info quality, reduce debug info size. The patch currently implements smaller set of command-line options(comparing to the proposal):
```
./llvm-dwarfutil [options] <input file> <output file>
--garbage-collection Do garbage collection for debug info(default)
-j <value> Alias for --num-threads
--no-garbage-collection Don`t do garbage collection for debug info
--no-odr-deduplication Don`t do ODR deduplication for debug types
--no-odr Alias for --no-odr-deduplication
--no-separate-debug-file
Create single output file, containing debug tables(default)
--num-threads <threads> Number of available threads for multi-threaded execution. Defaults to the number of cores on the current machine
--odr-deduplication Do ODR deduplication for debug types(default)
--odr Alias for --odr-deduplication
--separate-debug-file Create two output files: file w/o debug tables and file with debug tables
--tombstone [bfd,maxpc,exec,universal]
Tombstone value used as a marker of invalid address(default: universal)
=bfd - Zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec
=maxpc - Minus 1 for all addresses and minus 2 for DWARF v4 (or less) address ranges
=exec - Match with address ranges of executable sections
=universal - Both: bfd and maxpc
```
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D86539
This patch implements proposal https://lists.llvm.org/pipermail/llvm-dev/2020-August/144579.html
llvm-dwarfutil - is a tool that is used for processing debug info(DWARF) located in built binary files to improve debug info quality, reduce debug info size. The patch currently implements smaller set of command-line options(comparing to the proposal):
```
./llvm-dwarfutil [options] <input file> <output file>
--garbage-collection Do garbage collection for debug info(default)
-j <value> Alias for --num-threads
--no-garbage-collection Don`t do garbage collection for debug info
--no-odr-deduplication Don`t do ODR deduplication for debug types
--no-odr Alias for --no-odr-deduplication
--no-separate-debug-file
Create single output file, containing debug tables(default)
--num-threads <threads> Number of available threads for multi-threaded execution. Defaults to the number of cores on the current machine
--odr-deduplication Do ODR deduplication for debug types(default)
--odr Alias for --odr-deduplication
--separate-debug-file Create two output files: file w/o debug tables and file with debug tables
--tombstone [bfd,maxpc,exec,universal]
Tombstone value used as a marker of invalid address(default: universal)
=bfd - Zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec
=maxpc - Minus 1 for all addresses and minus 2 for DWARF v4 (or less) address ranges
=exec - Match with address ranges of executable sections
=universal - Both: bfd and maxpc
```
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D86539
This patch is extracted from D86539.
Current implementation of lookForDIEsToKeep() function skips types
duplications basing on the getCanonicalDIEOffset() data:
```
if (AttrSpec.Form != dwarf::DW_FORM_ref_addr && (UseOdr || IsModuleRef) &&
Info.Ctxt &&
Info.Ctxt != ReferencedCU->getInfo(Info.ParentIdx).Ctxt &&
Info.Ctxt->getCanonicalDIEOffset() && isODRAttribute(AttrSpec.Attr)) <<<<<
continue;
```
But that field is set after all compile units inside object file are processed:
```
for (auto &CurrentUnit : OptContext.CompileUnits)
lookForDIEsToKeep(.., &CurrentUnit, ..); // check CanonicalDIEOffset
DIECloner.cloneAllCompileUnits(); // set CanonicalDIEOffset
```
Thus, if the object file contains several compilation units - types would
not be deduplicated. The above solution works well for the case when the object file
contains only one compilation unit. But if the object file contains several compilation
units then types would not be deduplicated between these compilation units.
This patch changes the algorithm so that types were deduplicated between
compilation units from the same object file.
It produces binary incompatible output for the cases when several compilation units
are located inside the same object file.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D125469
Currently dsymutil will silently fail when processing binaries with
Dwarf 5 debug info. This patch adds rudimentary support for Dwarf 5 in
dsymutil.
- Recognize relocations in the debug_addr section.
- Recognize (a subset of) Dwarf 5 form values.
- Emits valid Dwarf 5 compile unit header chains.
To simplify things (and avoid having to emit indexed sections) I decided
to emit the relocated addresses directly in the debug info section.
- DW_FORM_strx gets relocated and rewritten to DW_FORM_strp
- DW_FORM_addrx gets relocated and rewritten to DW_FORM_addr
Obviously there's a lot of work left, but this should be a step in the
right direction.
rdar://62345491
Differential revision: https://reviews.llvm.org/D94323
This patch fixes a bug that would cause dsymutil to collect
.swiftinterface files for the Swift stdlib and other SDK
modules. There is no advantage in copying these since they should be
loaded from the ones bundled with LLDB's embedded Swift compiler
instead and copying them will cause LLDB to recompile them from source
instead of loading their prebuilt cached counterparts in the SDK.
rdar://problem/57463247
Differential Revisions: https://reviews.llvm.org/D75196
Summary:
This patch relands D71271. The problem with D71271 is that it has cyclic dependency:
CodeGen->AsmPrinter->DebugInfoDWARF->CodeGen. To avoid cyclic dependency this patch
puts implementation for DWARFOptimizer into separate library: lib/DWARFLinker.
Thus the difference between this patch and D71271 is in that DWARFOptimizer renamed into
DWARFLinker and it`s files are put into lib/DWARFLinker.
Reviewers: JDevlieghere, friss, dblaikie, aprantl
Reviewed By: JDevlieghere
Subscribers: thegameg, merge_guards_bot, probinson, mgorny, hiraditya, llvm-commits
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D71839
Alexey Lapshin