I'm building Firefox with debug information - I've tried both x86 and x64 versions - and it produced a gigantic 2+GB xul.dll. I believe that in the process it is also outputting bad DWARF information though, and preventing it from running (or being debugged).
I have two scenarios of the same (?) problem. The first is when all the debug information is in xul.dll. Trying to run Firefox gives the 'bad image' error: 0xc000007b referencing xul.dll. Running this in gdb outputs ""C:\cygwin64\home\Tom\working\ff-transfer\debugging/x64-Og-no-strip/firefox/firefox.exe": not in executable format: File format not recognized" - however I think this is bogus, as when I run it outside gdb, the command line starts up and the program produces a line of output before attempting to load xul.dll and failing. The second is when I have tried moving all the debug information into a separate file and linking them with --add-gnu-debuglink. This does run; but produced a segfault in firefox very early on. (In comparison - a debug build with stripped debug information does _not_ have the same failure scenario (it has a different failure scenario)). Running this in gdb this produced a "can't get string table" error upon loading the symbol file; and I don't have any symbol names. Output: (gdb) symbol-file ./firefox-debuglink/.debug/xul.dll.debug Load new symbol table from "./firefox-debuglink/.debug/xul.dll.debug"? (y or n) [answered Y; input not from terminal] Reading symbols from ./firefox-debuglink/.debug/xul.dll.debug..."C:\cygwin64\home\Tom\working\ff-transfer\debugging\firefox-debuglink\.debug\xul.dll.debug": can't get string table (gdb) run --no-remote -p Starting program: C:\cygwin64\home\Tom\working\ff-transfer\debugging\firefox-debuglink\firefox.exe --no-remote -p ... Assertion failure: false (cx->runtime()->gc.setParameter(key, value, lock)), at /builds/worker/workspace/build/src/js/src/jsapi.cpp:1543 Thread 1 received signal SIGSEGV, Segmentation fault. 0x06385aba in ?? () (gdb) (gdb) bt #0 0x06385aba in ?? () #1 0x0655d344 in ?? () #2 0x06769641 in ?? () ... 30 more frames of ?? () ... #33 0x00000000 in ?? () This is all using a MinGW version of gdb.exe from Equation Solution. Interestingly, if I use cygwin's gdb, I get the following (when trying the linked debug file): Dwarf Error: bad offset (0x70bee73e) in compilation unit header (offset 0x17441 + 6) [in module /home/Tom/working/ff-transfer/debugging/firefox-debuglink/lgpllibs.dll] (pause) warning: section .gnu_debuglink not found in /home/Tom/working/ff-transfer/debugging/firefox-debuglink/.debug/xul.dll.debug Error while reading shared library symbols for /home/Tom/working/ff-transfer/debugging/firefox-debuglink/xul.dll: "/home/Tom/working/ff-transfer/debugging/firefox-debuglink/.debug/xul.dll.debug": can't get string table (last two lines repeat a few dozen times slowly, then the gc.setParameter assertion error) I have various examples, and can fairly easily create new ones. For all of these 'target.zip' in the bottom pane is the file to download. (I've pre-selected the correct job, but it's Bd in the 'Windows MinGW all' line. Once selected it will say something like "Windows MinGW all MinGW builds for Windows 64-bits build-win64-mingw32/debug WM64(Bd)" in the bottom left to indicate x86 vs x64) x64 O0 https://treeherder.mozilla.org/#/jobs?repo=try&revision=030b88690e7966e2f16c97006e44327797119894&selectedJob=171280346 x64 O3 https://treeherder.mozilla.org/#/jobs?repo=try&revision=d96601a5d61fd8de6653441a30732b49dc403e09&selectedJob=171407096 x64 Og https://treeherder.mozilla.org/#/jobs?repo=try&revision=816fd51099f3418bc9dae125fbc9b26c2913b3a6&selectedJob=171407107 x64 Os https://treeherder.mozilla.org/#/jobs?repo=try&revision=2ff256d8863d23d0bd0ea314e4b702edd4de6aca&selectedJob=171407090 x86 Og https://treeherder.mozilla.org/#/jobs?repo=try&revision=13ff5041c81095c4f5502f2a1dfa4ba2b1d60f0e&selectedJob=171407200 x86 O0 https://treeherder.mozilla.org/#/jobs?repo=try&revision=030b88690e7966e2f16c97006e44327797119894&selectedJob=171280360 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
