Bug#796076: gcc-5: undefined reference errors with extern __inline__ (regression)

[Vincent Lefevre <vincent@vinc17.net>]

Package: gcc-5
Version: 5.2.1-15
Severity: important

On the following C code obtained with creduce (on a code obtained
when I wanted to test MPFR 3.1.3 against GMP 4.1.4):

extern __inline__ fn1() { fn2(); }

main() {}

I get the following error with gcc-5:

$ gcc-5 -w ct.i
/tmp/ccFWIDKK.o: In function `fn1':
ct.i:(.text+0xa): undefined reference to `fn2'
collect2: error: ld returned 1 exit status

No such problem with gcc-4.9, gcc-4.8 and gcc-4.7.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.1.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages gcc-5 depends on:
ii  binutils      2.25.1-1
ii  cpp-5         5.2.1-15
ii  gcc-5-base    5.2.1-15
ii  libc6         2.19-19
ii  libcc1-0      5.2.1-15
ii  libgcc-5-dev  5.2.1-15
ii  libgcc1       1:5.2.1-15
ii  libgmp10      2:6.0.0+dfsg-7
ii  libisl13      0.14-2
ii  libmpc3       1.0.3-1
ii  libmpfr4      3.1.3-1
ii  libstdc++6    5.2.1-15
ii  zlib1g        1:1.2.8.dfsg-2+b1

Versions of packages gcc-5 recommends:
ii  libc6-dev  2.19-19

Versions of packages gcc-5 suggests:
pn  gcc-5-doc         <none>
ii  gcc-5-locales     5.2.1-15
ii  gcc-5-multilib    5.2.1-15
pn  libasan2-dbg      <none>
ii  libatomic1-dbg    5.2.1-15
ii  libcilkrts5-dbg   5.2.1-15
ii  libgcc1-dbg       1:5.2.1-15
ii  libgomp1-dbg      5.2.1-15
ii  libitm1-dbg       5.2.1-15
ii  liblsan0-dbg      5.2.1-15
pn  libmpx0-dbg       <none>
ii  libquadmath0-dbg  5.2.1-15
ii  libtsan0-dbg      5.2.1-15
ii  libubsan0-dbg     5.2.1-15

-- no debconf information