Ubuntu
unity8 package

  1. Bug #1403758
  2. Comment #17

Comment 17 for bug 1403758

Revision history for this message
In , Giuseppe-dangelo (giuseppe-dangelo) wrote :

Created attachment 7474
testcase

The attached program changes the output from "true" to "false" when the -Bsymbolic / -Bsymbolic-functions options are passed to GCC. This happens on ARM -- on x86-64 output is always "true".

The program involves a comparison, within a shared library, of a PMF defined inside the shared library itself with the same PMF passed by the application.

Compile with:

 > g++ -fPIC -shared -Wall -o libshared.so -Wl,-Bsymbolic shared.cpp
 > g++ -fPIE -Wall -o main main.cpp -L. -lshared

(The long story is that Qt 5 is taking PMFs in its public API, and the comparison failing inside of Qt shared libraries is breaking code on ARM, as -Bsymbolic is set by default there.)

The bug has been acknowledged, and tentative patch has been kindly provided by W. Newton here:

> https://sourceware.org/ml/binutils/2014-01/msg00172.html

but there hasn't been any activity from what I can see, so I'm opening this bug report to keep track of the issue.

References:

> http://lists.linaro.org/pipermail/linaro-toolchain/2014-January/003942.html
> https://bugreports.qt-project.org/browse/QTBUG-36129