Generated symbols different on different archs with gcc-4.5

[Scott Kitterman]

Binary package hint: gcc-4.5

This affects multiple packages in Natty (all appear to be C++ based). You can also see this in kde4libs and opengtl. Here is an example:

https://launchpad.net/ubuntu/+source/kdegraphics/4:4.5.80-0ubuntu1 FTBFS on amd64 and i386 due to this problem.

The first few changes from http://launchpadlibrarian.net/59783195/buildlog_ubuntu-natty-amd64.kdegraphics_4:4.5.80-0ubuntu1_FAILEDTOBUILD.txt.gz are:

--- debian/libkexiv2-9.symbols (libkexiv2-9_4:4.5.80-0ubuntu1_amd64)
+++ dpkg-gensymbols0Pnv2H 2010-11-29 11:13:22.000000000 +0000
@@ -352,13 +352,23 @@
  _ZTVN11KExiv2Iface6KExiv2E@Base 4:4.5.80
  _ZTVN5Exiv210BasicErrorIcEE@Base 4:4.5.80
  _ZTVN5Exiv29ValueTypeIjEE@Base 4:4.5.80
- _ZThn20_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80
- _ZThn20_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface11MsgTextEditD0Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface11MsgTextEditD1Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface13SubjectWidgetD0Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface13SubjectWidgetD1Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface14AltLangStrEditD0Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface14AltLangStrEditD1Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80
- _ZThn8_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80
+ _ZThn16_N11KExiv2Iface11MsgTextEditD0Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface11MsgTextEditD1Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface13SubjectWidgetD0Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface13SubjectWidgetD1Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface14AltLangStrEditD0Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface14AltLangStrEditD1Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn16_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80-0ubuntu1
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn20_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn20_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80
+ _ZThn40_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80-0ubuntu1
+ _ZThn40_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80-0ubuntu1
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface11MsgTextEditD0Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface11MsgTextEditD1Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface13SubjectWidgetD0Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface13SubjectWidgetD1Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface14AltLangStrEditD0Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface14AltLangStrEditD1Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface15CountrySelectorD0Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu1# _ZThn8_N11KExiv2Iface15CountrySelectorD1Ev@Base 4:4.5.80

Similarly, the first few changes from http://launchpadlibrarian.net/59835990/buildlog_ubuntu-natty-powerpc.kdegraphics_4:4.5.80-0ubuntu2_FAILEDTOBUILD.txt.gz (note: The only difference between ubuntu1 and ubuntu2 is a per arch symbols file for amd64 to work around this exact problem) are:

--- debian/libkdcraw9.symbols (libkdcraw9_4:4.5.80-0ubuntu2_powerpc)
+++ dpkg-gensymbolszUBEVL 2010-11-30 00:43:38.000000000 +0000
@@ -377,35 +377,35 @@
  _ZTVN11KDcrawIface21RExpanderBoxExclusiveE@Base 4:4.5.80
  _ZTVN11KDcrawIface6KDcrawE@Base 4:4.5.80
  _ZTVN11KDcrawIface9RComboBoxE@Base 4:4.5.80
- _ZThn16_N11KDcrawIface12RExpanderBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface12RExpanderBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface12RIntNumInputD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface12RIntNumInputD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface14RLabelExpanderD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface14RLabelExpanderD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface15RDoubleNumInputD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface15RDoubleNumInputD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface16SqueezedComboBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface16SqueezedComboBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface19DcrawSettingsWidgetD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface19DcrawSettingsWidgetD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface21RExpanderBoxExclusiveD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface21RExpanderBoxExclusiveD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface9RComboBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
- _ZThn16_N11KDcrawIface9RComboBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface12RExpanderBoxD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface12RExpanderBoxD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface12RIntNumInputD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface12RIntNumInputD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface14RLabelExpanderD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface14RLabelExpanderD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface15RDoubleNumInputD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface15RDoubleNumInputD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface16SqueezedComboBoxD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface16SqueezedComboBoxD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface19DcrawSettingsWidgetD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface19DcrawSettingsWidgetD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface21RExpanderBoxExclusiveD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface21RExpanderBoxExclusiveD1Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface9RComboBoxD0Ev@Base 4:4.5.80
-#MISSING: 4:4.5.80-0ubuntu1~ppa3# _ZThn8_N11KDcrawIface9RComboBoxD1Ev@Base 4:4.5.80
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface12RExpanderBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface12RExpanderBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface12RIntNumInputD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface12RIntNumInputD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface14RLabelExpanderD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface14RLabelExpanderD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface15RDoubleNumInputD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface15RDoubleNumInputD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface16SqueezedComboBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface16SqueezedComboBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface19DcrawSettingsWidgetD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface19DcrawSettingsWidgetD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface21RExpanderBoxExclusiveD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface21RExpanderBoxExclusiveD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface9RComboBoxD0Ev@Base 4:4.5.80-0ubuntu1~ppa3
+#MISSING: 4:4.5.80-0ubuntu2# _ZThn16_N11KDcrawIface9RComboBoxD1Ev@Base 4:4.5.80-0ubuntu1~ppa3
+ _ZThn8_N11KDcrawIface12RExpanderBoxD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface12RExpanderBoxD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface12RIntNumInputD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface12RIntNumInputD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface14RLabelExpanderD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface14RLabelExpanderD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface15RDoubleNumInputD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface15RDoubleNumInputD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface16SqueezedComboBoxD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface16SqueezedComboBoxD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface19DcrawSettingsWidgetD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface19DcrawSettingsWidgetD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface21RExpanderBoxExclusiveD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface21RExpanderBoxExclusiveD1Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface9RComboBoxD0Ev@Base 4:4.5.80-0ubuntu2
+ _ZThn8_N11KDcrawIface9RComboBoxD1Ev@Base 4:4.5.80-0ubuntu2
dh_makeshlibs: dpkg-gensymbols -plibkdcraw9 -Idebian/libkdcraw9.symbols -Pdebian/libkdcraw9 return

[Matthias Klose (doko)]

any more information than the build logs? like a (preprocessed) source file, or a reduced testcase?

[Scott Kitterman (kitterman)]

No. Tell me how to generate those and I'll provide them.

[Colin Watson (cjwatson)]

Matthias, ping: Scott doesn't remember any communication outside the bug on this.

[Scott Kitterman (kitterman)]

<cjwatson> doko: any progress on bug 684703? the last comment on the bug is ScottK asking you for how to provide the information you requested; did you discuss that outside the bug?
<doko> cjwatson, ScottK: are these non-virtual thunks referred to in other libs?
<doko> sorry, s/libs/binaries/
<ScottK> They are non-virtual thunk.
<doko> ScottK: then why add these to the symbols files at all?
<ScottK> doko: It's what dpkg-gensymbols generates.
<ScottK> c++filt _ZThn16_N11KDcrawIface12RExpanderBoxD0Ev
<ScottK> non-virtual thunk to KDcrawIface::RExpanderBox::~RExpanderBox()
<ScottK> That's in libkdcraw9.symbols
<doko> ScottK: well, maybe ask buxy why he wants these mentioned in the symbols files?
<ScottK> doko: They weren't different on different archs before. Why now?
<buxy> I don't "pick" symbols, I take everything that's exported.
<ScottK> doko: I'm not a build system expert, but right now I have to test build that package on all archs to get a package that builds. That's not supportable.
<doko> ScottK, buxy: well, symbols files shouldn't be used unreflected for C++ libs. Debian #605833 is another (unrelated) case
<ubottu> Debian bug 605833 in gpsd "symbols file lists symbols from qt libs" [Important,Open] http://bugs.debian.org/605833
<buxy> doko: true, but MoDaX has done such work there that it gets more common...
<doko> buxy: which work?
<buxy> doko: the possibility to map symbols by their demangled name
<buxy> and other similar stuff
<doko> ScottK, buxy: so if we agree that these thunks don't belong the interface, then maybe make them optional by default?
<buxy> doko: I have no idea whether they belong to the interface or not, and I don't think that I want to have lots of special-cases in dpkg-gensymbols, in particular when these are difficult to identify (I don't want to always run c++filt)
<buxy> I rather suggest that the affected package uses the (c++) tag to match this symbol in arch-neutral way
<doko> buxy: well, these "special cases" are defined. http://www.codesourcery.com/public/cxx-abi/abi.html#mangling
<ScottK> doko: I don't know enough to have an opinion of if they should be optional by default. I just know it's a lot more effort to maintain symbols files if they vary per arch.
<doko> ScottK: sure, but you have to live with it
<seb128> bcurtiswx, it will be easier
<SpamapS> less confusing then to use -8 :)
<ScottK> doko: Why? I didn't have to live with it with gcc4.4.
<doko> ScottK: because types of parameters are mangled too

[Martin Pitt (pitti)]

There are various workarounds for this problem which the Kubuntu developers are using for now, and a solution is unlikely in two days, so moving milestone.

[Matthias Klose (doko)]

this needs fixes in the symbols files, not in GCC. we need to identify the packages in the next archive rebuild