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MinGW MiniDebugInfo
Summary
Analogously to the MiniDebugInfo change for native packages, install minimal debuginfos by default also for MinGW packages.
Owner
- Name: Sandro Mani
- Email: <manisandro@gmail.com>
- Release notes ticket: #119
Current status
Detailed Description
Currently the debuginfo data of MinGW binaries is completely stripped from the binary and placed in the respective .debuginfo file. This change proposes keeping the PE symbols in the binary, similarly to what was done for native binaries.
The change basically involves changing mingw-find-debuginfo.sh as follows:
diff --git a/mingw-filesystem/mingw-find-debuginfo.sh b/mingw-filesystem/mingw-find-debuginfo.sh
index de6dee1..261385f 100755
--- a/mingw-filesystem/mingw-find-debuginfo.sh
+++ b/mingw-filesystem/mingw-find-debuginfo.sh
@@ -25,7 +25,10 @@ do
echo extracting debug info from $f
mingw-objcopy --only-keep-debug $f $f.debug || :
pushd `dirname $f`
- mingw-objcopy --add-gnu-debuglink=`basename $f.debug` --strip-unneeded `basename $f` || :
+ keep_symbols=`mktemp`
+ mingw-nm $f.debug --format=sysv --defined-only | awk -F \| '{ if ($4 ~ "Function") print $1 }' | sort > "$keep_symbols"
+ mingw-objcopy --add-gnu-debuglink=`basename $f.debug` --strip-unneeded `basename $f` --keep-symbols="$keep_symbols" || :
+ rm -f "$keep_symbols"
popd
done
A test with some packages in this COPR repo shows that the price is a size increase of on average 17%:
| Binary | Stripped size | Size with symbols | Relative size change |
|---|---|---|---|
| libgio-2.0-0.dll | 1412 | 1656 | 117.28% |
| libglib-2.0-0.dll | 1092 | 1184 | 108.42% |
| libgmodule-2.0-0.dll | 28 | 32 | 114.29% |
| libgobject-2.0-0.dll | 312 | 352 | 112.82% |
| libgiomm-2.4-1.dll | 1284 | 1732 | 134.89% |
| libglibmm-2.4-1.dll | 432 | 588 | 136.11% |
| Qt5Concurrent.dll | 36 | 44 | 122.22% |
| Qt5Core.dll | 4884 | 5508 | 112.78% |
| Qt5DBus.dll | 548 | 652 | 118.99% |
| Qt5Gui.dll | 4408 | 5208 | 118.15% |
| Qt5Network.dll | 1568 | 1892 | 120.66% |
| Qt5OpenGL.dll | 328 | 404 | 123.17% |
| Qt5PrintSupport.dll | 376 | 448 | 119.15% |
| Qt5Sql.dll | 268 | 312 | 116.42% |
| Qt5Test.dll | 252 | 284 | 112.70% |
| Qt5Widgets.dll | 5716 | 6768 | 118.40% |
| Qt5Xml.dll | 216 | 268 | 124.07% |
Benefit to Fedora
Make it easier to debug Windows applications cross-compiled from Fedora, in particular:
- A convenient way to manage crash reporting is to ship gdb with the application, and in case of a crash, attach it to the dying process, collect a stacktrace, and ask the user to send it to the developer. For the developer it helps plenty if the stacktrace already contained symbol names, instead of being number-only.
- If you need to live-debug a deployed system, it is not always easy to obtain the correct debuginfo packages and install them along the binaries.
Scope
- Proposal owners:
- Change mingw-binutils toalso install a generic
mingw-nm, which will be used bymingw-find-debuginfo.sh - Change
mingw-find-debuginfo.shas outlined above - Rebuild all mingw packages
- Change mingw-binutils toalso install a generic
- Other developers: N/A (not a System Wide Change)
- Release engineering: #7005 (a check of an impact with Release Engineering is needed)
- List of deliverables: N/A (not a System Wide Change)
- Policies and guidelines: N/A (not a System Wide Change)
- Trademark approval: N/A (not needed for this Change)
Upgrade/compatibility impact
N/A (not a System Wide Change)
How To Test
- Wait for the packages rebuilt with the new mingw-find-debuginfo.sh to land, or use the test packages in this COPR repo.
- Make a Windows application using the binaries with minidebug infos crash
- The stacktrace should contain function names, i.e.
#0 0x000000000040157d in foo() () #1 0x00000000004015b5 in main ()
as opposed to being number only:
#0 0x000000000040157d in ?? () #1 0x00000000004015b5 in ?? () #2 0x00000000004013f7 in ?? () #3 0x000000000040152b in ?? () #4 0x0000000076af652d in KERNEL32!BaseThreadInitThunk () from C:\Windows\system32\kernel32.dll #5 0x0000000076d2c521 in ntdll!RtlUserThreadStart () from C:\Windows\SYSTEM32\ntdll.dll #6 0x0000000000000000 in ?? () Backtrace stopped: previous frame inner to this frame (corrupt stack?)
User Experience
N/A (not a System Wide Change)
Dependencies
N/A (not a System Wide Change)
Contingency Plan
- Contingency mechanism: N/A (not a System Wide Change)
- Contingency deadline: N/A (not a System Wide Change)
- Blocks release? N/A (not a System Wide Change), Yes/No
- Blocks product? none
Documentation
N/A (not a System Wide Change)
Release Notes
MinGW binaries contain symbol names by default for easier debugging.