Commit Graph

11 Commits

Author SHA1 Message Date
Jonas Devlieghere 7fb9bcd3da [dsymutil] Add option to print statistics about the .debug_info size.
This patch adds statistics about the contribution of each object file to
the linked debug info. When --statistics is passed to dsymutil, it
prints a table after linking as illustrated below.

It lists the object file name, the size of the debug info in the object
file in bytes, and the absolute size contribution to the linked dSYM and
the percentage difference. The table is sorted by the output size, so
the object files contributing the most to the link are listed first.

.debug_info section size (in bytes)
-------------------------------------------------------------------------------
Filename                                           Object         dSYM   Change
-------------------------------------------------------------------------------
basic2.macho.x86_64.o                                210b         165b  -24.00%
basic3.macho.x86_64.o                                177b         150b  -16.51%
basic1.macho.x86_64.o                                125b         129b    3.15%
-------------------------------------------------------------------------------
Total                                                512b         444b  -14.23%
-------------------------------------------------------------------------------

Differential revision: https://reviews.llvm.org/D79513
2020-05-06 19:48:45 -07:00
Jonas Devlieghere 0be7acab15 [dsymutil] Thread the VFS through dsymutil (NFC)
This patch threads the virtual file system through dsymutil.

Currently there is no good way to find out exactly what files are
necessary in order to reproduce a dsymutil link, at least not without
knowledge of how dsymutil's internals.  My motivation for this change is
to add lightweight "reproducers" that automatically gather the input
object files through the FileCollectorFileSystem. The files together
with the YAML mapping will allow us to transparently reproduce a
dsymutil link, even without having to mess with the OSO path prefix.

Differential revision: https://reviews.llvm.org/D79376
2020-05-04 20:21:33 -07:00
Alexey Lapshin 0ed2170dc4 [DWARFLinker][dsymutil] followup for 88c2137b6d
That patch is a followup for "Move DwarfStreamer into DWARFLinker".
It fixes build with LLVM_LINK_LLVM_DYLIB.
2020-04-08 16:46:52 +03:00
Alexey Lapshin 88c2137b6d [DWARFLinker][dsymutil][NFC] Move DwarfStreamer into DWARFLinker.
For implementing "remove obsolete debug info in lld", it is neccesary
to have DWARF generation code implementation. dsymutil uses DwarfStreamer
for that purpose. DwarfStreamer uses AsmPrinter. It is considered OK
to use AsmPrinter based code in lld(D74169). This patch moves
DwarfStreamer implementation into DWARFLinker, so that it could be reused
from lld.

Generally, a better place for such a common DWARF generation code would be
not DWARFLinker but an additional separate library. Such a library could
contain a single version of DWARF generation routines and could also
be independent of AsmPrinter. At the current moment, DwarfStreamer
does not pretend to be such a general implementation of DWARF generation.
So I decided to put it into DWARFLinker since it is the only user
of DwarfStreamer.

Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM
bundle matches for the dsymutil with/without that patch.

Reviewed By: JDevlieghere

Differential revision: https://reviews.llvm.org/D77169
2020-04-07 21:21:54 +03:00
Adrian Prantl ed8ad6ec15 Add an -object-path-prefix option to dsymutil
to remap object file paths (but no source paths) before
processing. This is meant to be used for Clang objects where the
module cache location was remapped using ``-fdebug-prefix-map``; to
help dsymutil find the Clang module cache.

<rdar://problem/55685132>

Differential Revision: https://reviews.llvm.org/D76391
2020-03-24 17:13:42 -07:00
Alexey Lapshin c074f5234d [DWARFLinker][NFC] Remove usages of "const object::ObjectFile" from DWARFLinker.
Summary:
DWARFContext has all the required information to access source debug info.
It is not necessary to use "const object::ObjectFile" to create DWARFContext.
Thus this patch removes all usages of "const object::ObjectFile"
from DWARFLinker. Instead, already created DWARFContext is passed
to DWARFLinker. The purpose is to not depend on "const object::ObjectFile".

The patch looks big, but most of changes are renamings and movements.

Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM bundle
matches for the dsymutil with/without that patch.

Reviewers: JDevlieghere, friss, dblaikie, aprantl

Reviewed By: JDevlieghere

Subscribers: hiraditya, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D75029
2020-02-28 13:26:22 +03:00
Fangrui Song 6520976064 [dsymutil] Delete unneeded parameter Triple from DWARFLinker
Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D74173
2020-02-07 11:33:27 -08:00
Alexey Lapshin a8c5a461a8 [Dsymutil][Debuginfo][NFC] #4 Refactor dsymutil to separate DWARF optimizing part.
Summary:
The primary goal of this refactoring is to separate DWARF optimizing part.
So that it could be reused by linker or by any other client.
There was a thread on llvm-dev discussing the necessity of such a refactoring:

http://lists.llvm.org/pipermail/llvm-dev/2019-September/135068.html.

This is a final part from series of patches for dsymutil.
Previous patches : D71068, D71839, D72476. This patch:

1. Creates lib/DWARFLinker interface :

   void addObjectFile(DwarfLinkerObjFile &ObjFile);
   bool link();
   void setOptions;

1. Moves all linking logic from tools/dsymutil/DwarfLinkerForBinary
   into lib/DWARFLinker.
2. Renames RelocationManager into AddressesManager.
3. Remarks creation logic moved from separate parallel execution
   into object file loading routine.

Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM bundle
matches for the dsymutil with/without that patch.

Reviewers: JDevlieghere, friss, dblaikie, aprantl, jdoerfert

Reviewed By: JDevlieghere

Subscribers: merge_guards_bot, hiraditya, jfb, llvm-commits, probinson, thegameg

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D72915
2020-01-23 18:16:32 +03:00
Vedant Kumar f0120556c7 [DWARF] Emit DW_AT_call_return_pc as an address
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.

In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.

The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.

Differential Revision: https://reviews.llvm.org/D72489
2020-01-15 13:02:23 -08:00
Alexey Lapshin f163755eb0 [Dsymutil][Debuginfo][NFC] #3 Refactor dsymutil to separate DWARF optimizing part.
Summary:
This is the next portion of patches for dsymutil.

Create DwarfEmitter interface to generate all debug info tables.
Put DwarfEmitter into DwarfLinker library and make tools/dsymutil/DwarfStreamer
to be child of DwarfEmitter.

It passes check-all testing. MD5 checksum for clang .dSYM bundle matches
for the dsymutil with/without that patch.

Reviewers: JDevlieghere, friss, dblaikie, aprantl

Reviewed By: JDevlieghere

Subscribers: merge_guards_bot, hiraditya, thegameg, probinson, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D72476
2020-01-13 23:33:25 +03:00
Alexey Lapshin 1cf11a4c67 [Dsymutil][Debuginfo][NFC] Reland: Refactor dsymutil to separate DWARF optimizing part. #2.
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
2020-01-08 14:15:31 +03:00